(BQ) Part 2 book General surgery prepare for the MRCS key articles from the surgery journal presentation of content: Anatomy of the caecum, appendix and colon, anatomy of the rectum and anal canal, the pathology of colorectal polyps and cancers, chemotherapy andradiotherapy for colorectal cancers,... and other contents.
Trang 1surgery Surgery also indicates recent advances that improve the understanding of disease and the safe and effective treatment of patients It comprises concise and systematically updated contributions that are produced over a three-year cycle Surgery is an excellent didactic tool to help consultant surgeons train their junior staff to become safe and competent surgeons.
Series editor
W E G Thomas MS FRCS FSACS(Hon) Consultant Surgeon, Honorary Senior Lecturer, Sheffield University, Member of Council and
past Vice President of the Royal College of Surgeons of England
Clinical editor
Michael G Wyatt MSc MD FRCS FRCSEd (ad hom) Consultant Surgeon, Freeman Hospital, Newcastle upon Tyne; Honorary Reader, Newcastle
University; Clinical Editor, SURGERY; Honorary Secretary, The Vascular Society of Great Britain and Ireland, and Member of the Court
of Examiners for the Intercollegiate MRCS
Editorial adviser
Harold Ellis CBE DM FRCS FRCOG
Emeritus Professor of Surgery, London University
Clinical Anatomist, Guy’s, King’s and St Thomas’s
School of Biomedical Science, London, UK
Editorial Board
Jon Anderson FRCS (CTh)
Consultant Cardiothoracic Surgeon
Hammersmith Hospital NHS Trust, London, UK
Emily Jane Baird MBChB MRCS (Glasgow)
Trauma and Orthopaedic Specialty Registrar,
West of Scotland Rotation; and President of
the British Orthopaedic Trainees Association
Frank Carey FRCPath
Professor and Consultant Histopathologist
Ninewells Hospital, Dundee, UK
Christopher R Chapple MD FRCS(Urol) FEBU
Visiting Professor, Sheffield Hallam University
Consultant Urological Surgeon,
Royal Hallamshire Hospital, UK
Ben Cresswell MBChB FRCS (Gen Surg)
Consultant Hepatopancreatobiliary Surgeon
The Basingstoke Hepatobiliary Unit
North Hampshire Hospital, UK
Michael J Kelly MChir FRCS MRCP (UK)
Consultant Colorectal Surgeon, Leicester, UK and National
Advisor Colorectal Cancer, NHS Improvement Court of
Examiners RCSEng
Peter Lamb MBBS FRCS(Eng) MD FRCS (Gen)
Consultant Upper GI and General Surgeon
Royal Infirmary of Edinburgh, UK
Anthony Lander PhD DCH FRCS (Paed)
Senior Lecturer in Paediatric Surgery and Consultant
Paediatric Surgeon, Birmingham Children’s Hospital, UK
Mary Murphy MB BCh, BAO, FRCS (SN)
Consultant Senior Lecturer in SurgeryBristol Royal Infirmary, Bristol, UKHelen Sweetland MD FRCS (Ed)Reader in Surgery and Honorary Consultant SurgeonCardiff and Vale NHS Trust, UK
William Wallace MBChB(Hon) PhD FRCPE FRCPathConsultant Pathologist and Honorary Senior LecturerRoyal Infirmary of Edinburgh, UK
Robert Wilkins MA DPhil (Oxon)Lecturer in PhysiologyDepartment of Physiology, Anatomy & Genetics
St Edmund Hall, University of Oxford, UKMark Wilkinson PhD FRCS (Orth)
Professor of Orthopaedic SurgeryUniversity of Sheffield, UKConsultant Orthopaedic SurgeonNorthern General Hospital, Sheffield, UK
Surgical and Clinical Anatomy for the MRCS exam
Series editors
Harold Ellis CBE DM MCh FRCS FRCOG LondonVishy Mahadevan MB BS PhD FRCS LondonThis series is available only on the website:
www.surgeryjournal.co.uk
Trang 2Anorectal anomalies and Hirschsprung disease (including stomas)
Jonathan Sutcliffe Ian Sugarman Marc Levitt
646
TEST YOURSELFTest yourself: MCQ and extended
A great revision guide for the MRCS and beyond
Based entirely on the Intercollegiate Surgical Curriculum
Issue Editor
Anthony Lander frcs ( p aed )
Consultant Paediatric Surgeon
Birmingham Children’s Hospital,
Birmingham, UK
www.surgeryjournal.co.uk
ONLINE, IN PRINT, IN PRACTICE
Trang 3Paediatric fluid and
electrolyte therapy
guidelines
Anthony Lander
Abstract
The advice in this article is based on a multidisciplinary consensus
opinion generated by the Association of Paediatric Anaesthetists and
on a National Patient Safety Agency (NPSA) recommendation of March
2007 entitled ‘Reducing the risk of hyponatraemia when administering
intravenous infusions to children’ To this has been added advice from
our specialist hospital fluid policy.
KeywordsHyponatraemia; intravenous fluids; paediatrics
The National Patient Safety Agency (NPSA) Alert of 2007 was
ex-pected to bring about a widespread change in postoperative
maintenance fluid administration such that children would receive
solutions containing 0.9% saline or Hartmann’s solution rather
than solutions containing 0.18% or 0.45% saline in glucose
Tele-phone surveys show that practice has changed such that 0.18%
saline has mostly been removed from wards but that the preferred
postoperative fluid is often 0.45% saline with 5% dextrose
The potential benefit of the recommendations is that the
chances of serious error from bad prescribing will be reduced
However, hypernatraemia or hyperchloraemia should be looked
for in those children having 0.9% saline or Hartmann’s solution
for protracted periods and instances reported appropriately
NPSA: The dangers of 4% glucose 0.18% saline
The NPSA reminded clinicians of the dangers of the use of
low-sodium-containing fluids such as 0.18% saline with 4% glucose
This fluid has always been inappropriate when used for
resuscita-tion or when used to replace most fluid and electrolyte deficits or
when given at excessive rates when maintenance fluids were
intended The risk is one of precipitating hyponatraemia which can
be fatal Sadly even in university and tertiary centres local audits
have shown that inappropriate prescriptions like this are not rare
Many surgeons have traditionally used 4% glucose with
0.18% saline as a maintenance fluid when given at appropriate
rates in well children based on their weight This or 0.45% saline
with 5% glucose has been traditionally given at reduced rates in
the postoperative period
The term isotonic is now to be considered in relation to the
tonicity of the electrolyte components of fluids Thus 0.18%
sa-line with 4% glucose and 0.45% sasa-line with 5% glucose are now
to be considered hypotonic since the glucose is ignored
Importantly the NPSA wanted all stocks of 4% glucose with0.18% saline removed from non-specialized areas and thisshould now have happened (Table 2)
Postoperative fluid prescriptionse new regulationsThe NPSA say that postoperative fluid prescriptions should neverinclude 4% glucose with 0.18% saline or 0.45% saline with 5%glucose and outside the neonatal period can only be chosen from:
0.9% saline
0.9% saline with 5% glucose
Ringer’s lactate/Hartmann’s solution
4.5% albumin
For neonates 10% glucose with 0.18% saline and 0.45% salinewith 5% glucose remain options
Prescribing intravenous (IV) fluids
IV fluids should be prescribed with the same care and attention
as given to other drugs No one prescribes analgesics when tibiotics are needed and no one should prescribe maintenancefluids when replacement fluids are intended
an-Fluids are given intravenously for the following four reasons:
circulatory support in resuscitating vascular collapse
replacement of previous fluid and electrolyte deficits
maintenance
replacement of ongoing losses
IV fluid prescriptionsPractice should be determined locally and ideally IV fluids should beprescribed daily by the team involved in the child’s care either at themorning round or in the early evening before handover
Fluids should not be being prescribed by the night team whowill not be as familiar with the patient unless the fluid man-agement requires fine-tuning in response to the clinical situation
or as a result of investigations Such a patient would then havehad a detailed and specific handover
PotassiumPotassium 20 mmol/litre (0.15%) (10 mmol in each 500-ml bag)should be included in maintenance fluids and in replacementfluids unless there are specific contraindications If there arespecial reasons not to give potassium these should be detailed inthe notes Potassium is not included in the first 24 hours of lifenor traditionally in the first 24 hours after surgery However, itwill be given if Hartmann’s solution is prescribed Rememberthat most potassium is intracellular and so a slightly lower serumlevel than normal may indicate marked potassium depletion.Monitoring
Monitoring of the patient’s weight is important and particularlyhelpful in managing rehydration Urine specific gravity is also agood guide to rehydration
Daily electrolytes are mandatory in those solely on IV fluidsfor more than a day The electrolytes should be looked at in thecontext of previous results and not simply in relation to thenormal values Typically when the serum sodium falls fluid re-striction is appropriate and when it rises fluid rates can beincreased This is particularly relevant in managing fluids in thepostoperative period A falling sodium is usually a sign of overadministration of fluid and not of giving too little sodium
Anthony Lander PhD FRCS (Paed) DCH is a Consultant Surgeon at
Bir-mingham Children’s Hospital, BirBir-mingham, UK Conflicts of interest:
none declared.
Trang 4Circulatory support in shock
The following fluids are appropriate for bolus administration at
10 or 20 ml/kg given over periods of up to 20 minutes:
It is inappropriate to use low-sodium-containing fluids in these
situations 0.18% saline or 0.45% saline in glucose is not to be
used for circulatory resuscitation Hyponatraemia can result and
this can be fatal
Monitoring is typically based on the clinical response, blood
pressure, capillary refill, blood gasses, etc Serum electrolytes
should be checked in anyone needing circulatory resuscitation
Correcting previous fluid and electrolyte deficits
However estimated, previous losses are typically between 5 and
15% of body weight Sometimes the weight loss is accurately
known The fluid used to replace this deficit should be isotonic
0.9% sodium chloride or Ringer’s lactate/Hartmann’s solution
A 15-kg child who is 5% dehydrated has a water deficit of 750 ml
Audits have shown that it is not an uncommon misconception that
10% dehydration can be corrected by increasing maintenance fluid
rates by 10%! This is clearly incorrect
Hypovolaemia, should be corrected with an initial fluid bolus
of 10e20 ml/kg of an isotonic fluid or colloid, repeated as
necessary followed by a slower correction of residual tion with an isotonic fluid, taking into account ongoing losses,serum electrolytes and urine output
dehydra-Maintenance fluid requirements in childrenMaintenance fluid requirements are still to be calculatedaccording to the recommendations of Holliday and Segar(Table 1) Table 1is a starting point only and the individualchild’s response to fluid therapy should always be monitored andappropriate adjustments made
In children outside the neonatal period 0.45% saline in glucose
or Hartmann’s solution or 0.9% saline are options supported by theNPSA However, in the postoperative period it recommends notusing 0.45% saline These fluids give more than the daily re-quirements of sodium, but the risks of this are considered to be lessthan the risks of hyponatraemia if 0.18% saline is administered Ourpreferred fluid is Hartmann’s solution since this gives less chloride
In term neonates during the first 48 hours of life 10% glucoseshould be given at a rate of 60 ml/kg/day unless there is aclinical indication for increased or decreased fluid administra-tion Sodium would be added to IV fluids on day 2e3 depending
on renal function, serum sodium and weight
From day 3 of life maintenance fluid should be 0.18% saline with10% glucose given at a rate of 4 ml/kg/hour or 100e120 ml/kg/day.Preterm babies or those under 2 kg may require higher rates ofadministration and should be assessed at least daily by assess-ment of weight and electrolytes
Normal water, electrolyte, energy and protein requirements
Table 1
Commonly available crystalloid fluids
(mmol/litre) (mmol/litre) (mmol/litre) (kcal/litre)
Trang 5Maintenance fluid requirements may need to be increased in
children with pyrexia, excess sweating, hypermetabolic states
such as burns or when radiant heaters or phototherapy is used
There is no consensus on whether maintenance fluid
re-quirements should be reduced in children on a paediatric intensive
care unit (PICU) who are sedated and ventilated with humidified
gases
Simple calculations will show that the electrolyte
re-quirements are met if 0.18% NaCl, 0.15% KCl is administered at
the prescribed rates But the dangers of hyponatraemia are
considered to outweigh the benefits of restricting the sodium and
chloride content of the fluid
Fluids given during operations
During surgery the majority of children may be given fluids
without glucose Blood glucose should be monitored
Maintenance fluid used during surgery should be isotonic
such as 0.9% sodium chloride or Ringer’s
lactate/Hart-mann’s solution
Neonates in the first 48 hours of life should be given
glucose during surgery
Preterm and term infants already receiving
glucose-cont-aining solutions should continue with them during surgery
Infants and children on parenteral nutrition preoperatively
should continue to receive parenteral nutrition during
surgery or change to a glucose-containing maintenance
fluid and blood glucose monitored
Children of low body weight (less than third centile) or
having prolonged surgery should receive a
glucose-containing maintenance fluid (1e2.5% glucose) or have
their blood glucose monitored during surgery
Children having extensive regional anaesthesia with a
reduced stress response should receive a
glucose-containing maintenance fluid (1e2.5% glucose) or have
their blood glucose monitored
All losses during surgery should be replaced with an
isotonic fluid such as 0.9% sodium chloride, Ringer’s
lactate/Hartmann’s solution, a colloid or blood, depending
on the child’s haematocrit
In children over 3 months of age the haematocrit may be
allowed to fall to 25% Children with cyanotic congenital
heart disease may need a higher haematocrit to maintain
oxygenation
Postoperative fluid management
Some preoperative surgical conditions are associated with
increased antidiuretic hormone (ADH) production: empyema,
sepsis, shock, etc Operative trauma, pain, nausea and vomiting
also contribute to ADH release
The NPSA alert has recommended that 0.18% and 0.45% saline
in glucose should not be used for postoperative maintenance as
they may cause hyponatraemia due to retention of free water
released after metabolism of glucose from the solution
It recommends that the following fluids alone should be prescribed:
Ongoing losses from drains or nasogastric tubes should bereplaced with an isotonic fluid such as 0.9% sodium chloride
It is possible that this change in practice may lead to high serumchlorides and these should be monitored Hyperchloraemia cangive rise to headaches, but it is less dangerous than hyponatraemia.Oral fluids should be started and increased after surgery whilst
IV fluids are reduced and then discontinued The rate at whichthis happens depends upon the child and the surgery
Monitoring of fluid therapy
Serum electrolytes do not need to be measured in all operatively healthy children prior to elective surgerywhere IV fluids are to be given for the duration of surgeryand for a short period thereafter
pre- If there has been bowel preparation or there is unshuntedhydrocephalus, electrolytes should be checked preoperatively
Serum electrolytes need to be measured preoperatively inall children presenting for elective or emergency surgerywho require IV fluid to be administered prior to surgery
Children should be weighed prior to fluids being prescribed
Serum electrolytes should be measured every 24 hours inall children on IV fluids or more frequently if abnormal
Children should be weighed daily while on IV fluids unlessthis is difficult
A fluid input/output chart must be carefully maintainedand checked by the prescribing doctor
Common electrolyte derangementsHyponatraemia
Hyponatraemia (serum Na <135 mmol/litre) may occur in
a number of situations, but is commonly seen wheninappropriate fluids have been administered or followingsurgery with any fluid regime
Low-sodium-containing (0.18% NaCl) (hypotonic) tenance fluids are more likely to precipitate hyponatraemia
main-if fluids rates are inappropriately high
Presenting features of hyponatraemia include seizures orrespiratory arrest Headache is a consistent early sign ofhyponatraemia in adults, but is rarely reported in children
Hyponatraemic encephalopathy should be managed as amedical emergency on PICU
Hyponatraemic seizures respond poorly to anticonvulsantsand initial management is to give an infusion of 3% sodiumchloride solution One ml/kg of 3% sodium chloride willnormally raise the serum sodium by 1 mmol/litre Serum Nashould be raised quickly until the child has regained con-sciousness and has stopped fitting or the serum Na is above
125 mmol/litre The amount of Na required can be calculatedaccording to the following formula:
mmol of Na required¼ ð130 present serum NaÞ 0:6
Trang 6Asymptomatic hyponatraemia does not require active
correction with 3% sodium chloride solution The dehydrated
child may be treated with enteral fluids or if not tolerated, with
IV 0.9% sodium chloride solution
The child with asymptomatic hyponatraemia and normal or
increased volume status, if taking oral fluids should be
vol-ume restricted or if on IV fluids should have fluid
adminis-tered at 50% of maintenance rate If eating, salt can be added
to the food
Hypernatraemia
Hypernatraemia (serum Na >150 mmol/litre) commonly
oc-curs as a result of excessive water loss, restricted water intake
or an inability to respond to thirst It may also occur in infants
given incorrectly made feeds Hypernatraemia can be fatal
Signs of hypernatraemia are more severe when it develops
rapidly or when the serum Na is greater than 160 mmol/
litre Chronic hypernatraemia is often well tolerated
because of cerebral compensation
The true degree of dehydration is often underestimated if
clinical signs alone are used compared to loss of weight
Intravascular volume is often well preserved during the initial
stages
The management of hypernatraemic dehydration consists
of initial volume replacement with 0.9% sodium chloride
given in boluses of 20 ml/kg to restore normovolaemia
Complete correction should then be done very slowly over
at least 48 hours to prevent cerebral oedema, seizures and
brain injury The serum Na should be corrected at a
reduction of no more than 12 mmol/litre/day with 0.45%
sodium chloride or 0.9% sodium chloride in glucose
In hypernatraemic dehydration it is important to give
maintenance fluid alongside fluid to correct dehydration
Potassium imbalance
Hypokalaemia (serum K <3.5 mmol/litre) produces
contractility and paralytic ileus If possible oral
supple-ments of 3e5 mmol/kg/day should be given Orange juice
and bananas are rich in potassium
In severe hypokalaemia (serum K <3 mmol/litre), IV
correction should be no faster than 0.25 mmol/kg/hour
using a maximum peripheral concentration of 40 mmol/
litre KCl (as per British National Formulary for Children)
For a more rapid correction, the patient should be in PICU
and the infusion administered via a central line
Hyperkalaemia (serum K >5.5 mmol/litre) causes skeletal
muscle weakness and electrocardiography (ECG) changes
when serum K is greater than 7 mmol/litre
Immediate treatment of hyperkalaemia is to antagonize
membrane effects by giving 100 mg/kg of 10% calcium
gluconate This equates to 0.5 ml/kg of a 10% solution (1
ml 10% calcium gluconate contains 0.22 mmol calcium)
Advanced Paediatric Life Support (APLS) recommendation)
Alongside this it is important to increase intracellular shift
bicar-bonate, an infusion of 0.3e0.5 g/kg/hour of glucose with 1
unit of insulin for every 5 g of glucose or to give 2.5e5 mg
nebulized salbutamol (5 mg/kg in neonates IV)
Removal of potassium from the body can be achieved bygiving 1 g/kg calcium resonium rectally or orally, by use offurosemide 1 mg/kg or by dialysis or haemofiltration.Calcium imbalance
Hypocalcaemia (corrected total Ca <2 mmol/litre or
<1.5 mmol/litre in neonates) may produce symptoms oftwitching and jitteriness, perioral, finger and toe paraes-thesia, masseter and carpopedal spasm, prolonged QT in-terval and reduced cardiac contractility
Immediate treatment is with 10% calcium gluconate 0.5ml/kg to a maximum of 20 ml over 10 minutes or 10%calcium gluconate 0.2 ml/kg to a maximum of 10 ml over
10 minutes Warning: there is a danger of extravasationcausing tissue injury
The central venous route should be considered for tion with continuous ECG monitoring during injection
injec- Calcium levels appear low in the newborn because of lowalbumin levels There is a normal physiological fall in cal-cium concentration after birth which rises after the secondday Causes of hypocalcaemia in the newborn are encepha-lopathy, renal failure, Di George syndrome, disorderedmaternal metabolism or maternal diabetes mellitus.Pyloric stenosis: hypochloraemia correction
Children with pyloric stenosis typically present with a mildhypochloraemic alkalotic dehydration Resuscitation can bebased on the serum chloride in most children
Calculate the chloride deficit and replace over 12e48 hoursdepending on severity
Chloride deficit¼ 2=3 weight ðkgÞ 110 Cl
:Use 0.9% saline 0.15% Kþ(170 mmol Cl/litre) or 0.45% saline,5% glucose 0.15% Kþ(95 mmol Cl/litre)
SummaryGreat care and respect should be given to IV fluid management It
is important to understand the basic science, the risks and nowthe national guidelines which have been outlined here and
Example: a 3.3-kg child is mildly dehydrated with a ClLof
If the serum chloride is then remeasured and the bicarbonate checked, they will most likely be corrected.
When corrected use appropriate maintenance fluids, but continue
to replace nasogastric losses with 0.9% saline 0.15% KD.
Trang 7This is a review of the pathology of the major solid extracranial neoplasms
of childhood that may be encountered in paediatric surgical practice It
does not include the various leukaemias, lymphomas and
reticuloendothe-lial neoplasms that make up a large proportion of childhood malignancy.
The rarity of childhood tumours and common overlapping histological
fea-tures may make the diagnosis particularly challenging A variety of
histo-pathological parameters may be used to give prognostic information
including degree of tumour differentiation, presence or absence of
anaplasia, extent of necrosis and mitotic index Important genetic
aberra-tions of both prognostic and diagnostic significance are also discussed.
Increasingly the management of these tumours requires a multidisciplinary
approach with close collaboration between the surgical team, pathologist
and molecular scientist.
KeywordsChildhood; genetics; pathology; tumour
Neuroblastoma
Neuroblastoma is the most common solid extracranial neoplasm
in children (1 in 10,000 live births per year in the UK) accounting
internationally for 6e10% of all childhood malignancies It is a
nervous system tumour, derived from cells of the neural crest
which give rise to the sympathetic nervous system, and occurs
predominantly in those aged under 5 years It usually arises in
the retroperitoneum (50% originating in the adrenal glands), but
may occur anywhere along the line of the sympathetic chain
Clinical presentation depends upon tumour location, age and
associated clinical symptoms, which may include weight loss,
fever, gastrointestinal tract disturbances, and anaemia (as well as
symptoms related to tumour expansion) Neuroblastoma is often
widely disseminated at the time of diagnosis, with 70e80% of
patients aged more than 1 year presenting with metastatic
dis-ease, usually to lymph nodes, liver skin, bone or bone marrow
Histology (Figure 1): neuroblastomas are composed of dense
sheets of small, round, blue cells traversed by fine fibrovascular
septa Homer-Wright pseudorosettes are observed in 15e50% of
tumour samples and consist of neuroblasts with eosinophilic
neuritic processes that polarize towards a central point Theseneuritic processes (also called neuropils) are a pathognomonicfeature of neuroblastoma Necrosis and calcification (often in a
‘chicken wire’ fashion around individual cells) are usual ings Positive immunohistochemistry for neural markers (forexample S100, neuron-specific enolase) may help differentiateneuroblastomas from other small, round blue-cell tumours (forexample Ewing’s/primitive neuroectodermal tumours, rhabdo-myosarcoma) Electron microscopy may show ultrastructuralfeatures (for example neurofilaments, neurotubules, synapticvesicles, dense core granules) confirming the neural nature of thetumour
find-Various histological grading systems designed to give nostic information are in use They grade tumour characteristics,
prog-in particular the percentage of differentiated elements, mitoticcount and karyorrhectic index Neoplasms containing matureganglion cells as well as immature neuroblasts are termed ‘gan-glioneuroblastomas’ and tend to have a better prognosis thanneuroblastomas Ganglioneuroma, which is more common inadults, is benign and consists of abnormal (but mature)gangliocytes
Molecular genetics may show a wide variety of chromosomalimbalances, including hyperdiploidy for whole chromosomes,deletions of chromosome arms 1p and 11q (regions which maycontain tumour suppressor genes) and, most commonly, gains ofchromosome arm 17q Amplification of the MYCN proto-oncogene occurs in about 25% of cases
Management: different treatments are required for differentstages of disease The age at diagnosis (prognosis is better forthose aged <1 year) and the other prognostic variables listedabove must be considered The International NeuroblastomaRisk Group Task Force has identified the following factors to behighly statistically significant in providing pre-treatment riskstratification: stage, age, histologic category, grade of tumourdifferentiation, status of the MYCN oncogene (amplification is anadverse prognostic feature), chromosome 11q status and DNAploidy Neuroblastomas may be managed by surgery and radio-therapy; chemotherapy and bone marrow transplantation may berequired for higher-stage disease This is an aggressive neoplasmand less than 50% of cases are cured
Wilms’ tumour (malignant nephroblastoma)
In the UK, Wilms’ tumour accounts for about 95% of renal lignancies in childhood and 5% of all childhood malignancies.Most patients present with an abdominal mass (noted by theparents) between the ages of 1 year and 3 years Rarely it pre-sents with pain, haematuria, hypertension or even rupture.Sporadic cases of Wilms’ tumour have been reported in adultsand a rare extra-renal variant exists Prognosis is related to thestage of the disease at diagnosis, histological features, age (morefavourable for those aged<2 years) and tumour size Metastaticspread is typically to the lungs
ma-Histology: the classic triphasic Wilms’ tumour consists of threecell types: epithelial, blastemal and stromal (Figure 2) All
Lesley Christie FRCPath is a Consultant Histopathologist at Ninewells
Hospital and Medical School, Dundee Conflicts of interest none
declared.
Steve Lang FRCPath is a Consultant Histopathologist at Ninewells
Hospital and Medical School, Dundee, UK Conflicts of interest: none
declared.
Trang 8components are represented to varying degrees in most tumours,
but monophasic or biphasic types occur
Undifferentiated blastema is extremely cellular, composed
of small round or oval primitive cells containing small amounts
of cytoplasm Typically, these cells grow in sheets, nodules or
cords Mesenchymal stroma consists of spindle cells which may
differentiate along various cell lines, particularly skeletal and
smooth muscle Epithelial tissue comprises embryonic tubular
and glomerular elements Other cell types including squamous,
transitional, neural, cartilage and adipose tissue may be seen
The presence or absence of anaplasia (large, hyperchromatic
nuclei, abnormal mitosis) designates the tumour as having
unfavourable or favourable histology, respectively
Genetics: Wilms’ tumour develops in otherwise healthy children,
but less than 10% of tumours occur in individuals with
eDrash and Wilms’ tumour, aniridia, genitourinary ities, mental retardation (WAGR syndrome) Hereditary or spo-radic Wilms’ tumour may result from specific germlinemutations in the Wilms’ tumour gene (WT1) located on the shortarm of chromosome 11 and may also be associated with a variety
abnormal-of genitourinary abnormalities Loss abnormal-of heterozygosity for mosomes 1p and 16q appears to be an adverse prognostic indi-cator even in cases with favourable histology
chro-Management: the overall cure rate of Wilms’ tumour in the UKhas risen dramatically to about 80% due to improvements insurgery, chemotherapy and radiotherapy Stage I and Stage IItumours without anaplasia (favourable histology) are managedwith nephrectomy and chemotherapy Additional chemothera-peutic agents and radiotherapy are employed for higher stage andanaplastic tumours (unfavourable histology) Treatment hasbeen standardized following the publication of the NationalWilms’ Tumour Study
Other malignant renal tumours in children with a poorerprognosis than that of Wilms’ tumour include:
clear cell sarcoma of the kidney (also called bone stasising renal tumour of childhood), accounting foraround 5% of paediatric renal neoplasms
meta- malignant rhabdoid tumour of the kidney (the mostaggressive tumour in this group, accounting for around 2%
as well as bilaterality, the tumour may also be present in thepineal gland or suprasellar/parasellar regions (trilateral retino-blastoma) Retinoblastomas are often quite large at presentationand are characteristically identified by the presence of a whitepupillary reflex Spread may occur to the optic nerve and brain
by direct extension or through the arachnoid space; distantspread is commonly to the skeleton
Histology: retinoblastoma is typically composed of sheets ofsmall, round, hyperchromatic blue cells although a trabecular ornested pattern of growth may be present A characteristic feature(not always seen) is evidence of retinal differentiation in the form
of FlexnereWintersteiner rosettes Extensive areas of coagulativenecrosis may be evident as the rapidly growing tumour outstripsits vascular supply A rare benign variant exists in which thetumour is composed of mature cells (retinocytoma)
Genetics: retinoblastoma arises due to inactivation of the noblastoma gene (RB1) located on chromosome 13 Both allelesmust be mutated for this to occur e a classic example of theKnudson ‘two-hit’ hypothesis The first hit may be a germlinemutation in which every cell of the body has one mutant allele;
reti-Figure 1 Neuroblastoma (a) Fibrillary background; (b) undifferentiated
cells.
Figure 2 Triphasic Wilms’ tumour (a) Blastemal element; (b) epithelial
element; c, stromal element.
Trang 9the second hit represents a somatic mutation The germline
mutation may be transmitted as a dominant trait from a parent,
or, as in most retinoblastoma cases, represents a new mutation
Children with an inherited mutant retinoblastoma gene are at
greatly increased risk of other malignancies, particularly
osteo-sarcoma All bilateral retinoblastomas and a proportion of
uni-lateral cases (15% of cases in the UK) arise in children who carry
the mutant gene
Management aims to preserve as much sight as possible, and
may include laser photocoagulation and local radiotherapy
Enucleation is performed if the tumour is extensive Systemic
chemotherapy may be employed if the surgical margin of the
optic nerve is involved by tumour or there is evidence of
extension into the brain or metastatic spread Long-term survival
for retinoblastoma is about 95% in the UK
Hepatoblastoma
Hepatoblastoma is the most common malignant liver tumour in
children However, it is rare even among the other solid
malig-nancies, with about one child per million per year developing the
disease in the UK Unlike hepatocellular carcinoma, there is
no association with cirrhosis The typical presentation is an
asymptomatic abdominal mass noted by the parents in a child
aged under 3 years Sporadic cases occur in older children,
teenagers and adults; 10e20% of children have metastases at
presentation, with the lung being the predominant site Serum
concentrations of alpha-fetoprotein are often elevated The
location of the tumour within the liver, its size and extent of
spread are usually determined by computed tomography (CT)
and hepatic angiography
Wiedemann syndrome, and those with familial adenomatous
polyposis are at about 500 times greater risk of developing the
disease
Histology: hepatoblastoma may be composed entirely of
epithelial elements (50%) or a combination of epithelium and
mesenchyme The most common epithelial subtype is the pure
fetal form, in which the cells resemble hepatocytes and grow in a
pattern mimicking fetal liver Foci of extramedullary
haemato-poiesis may be seen The embryonal form is composed of cells
which appear less mature and has a predominantly solid growth
pattern The small cell undifferentiated hepatoblastoma is
composed of sheets of undifferentiated anaplastic small cells and
has the poorest prognosis If stromal elements are present (mixed
tumours), they may be undifferentiated or consist of bone and/or
cartilage
Genetics: there has been limited study of their cytogenetics due
to the rarity of these tumours The most common findings are
trisomies of 2, 8 and 20 and rearrangements of 1q Aneuploidy
may be associated with a poorer prognosis
Management of hepatoblastoma is surgical resection
Cytore-ductive chemotherapy may be used in order to allow removal of
a previously unresectable tumour The prognosis of patients who
have had complete surgical removal with no evidence of residual
disease is excellent; the outlook for those who have residualdisease (despite aggressive chemotherapy) is poor A transplantmay be considered in tumours that involve the whole liver.Concentrations of a-fetoprotein may be used to determineresponse to therapy and to detect recurrence
RhabdomyosarcomaRhabdomyosarcoma is a highly malignant tumour that arisesfrom the primitive skeletal muscle cell (rhabdomyoblast) andaccounts for over 50% of soft-tissue tumours in children in the
UK There are three main subtypes of rhabdomyosarcoma;embryonal, alveolar and pleomorphic; the latter is extremely rare
in children and is not discussed further The tumours may arise
as part of a familial syndrome, but the vast majority are sporadic
Embryonal rhabdomyosarcoma occurs predominantly inchildren aged less than 5 years, but may occur in adoles-cents and very rarely in adults It usually arises in the headand neck region, as well as the biliary and urogenitaltracts Macroscopically, it appears poorly circumscribed,white and soft If the tumour grows just beneath a mucosalmembrane (for example vagina, bladder) it may form apolypoidal mass resembling a bunch of grapes and isfurther then termed a ‘botryoid rhabdomyosarcoma’.Embryonal rhabdomyosarcoma is composed of sheets ofspindle shaped cells (rhabdomyoblasts) The identification
of cross-striations on light microscopy is useful (but notessential) for the diagnosis There is a characteristic vari-ability in cellularity within the tumour, the less cellularareas containing abundant mucoid material
Alveolar rhabdomyosarcoma is seen in older children andyoung adults and usually occurs in the extremities andperineal region The tumour consists of nests of round oroval cells separated by fibrous septa (Figure 3) Centrally,the cells become detached, leaving spaces A solid variety
of the alveolar rhabdomyosarcoma exists in which the cellnests are cohesive, a feature which may cause some
Figure 3 Alveolar rhabdomyosarcoma (a) Rhabdomyoblasts; (b) fibrous septae covered by a lining of single cells; (c) discohesive cells.
Trang 10diagnostic difficulties The alveolar subtype has a poorer
prognosis than the embryonal variant
Immunohistochemistry: the skeletal muscle origin of the
tumour must be established in order to make a diagnosis of
rhabdomyosarcoma A wide panel of immunohistochemistry
may be employed, with the most useful stains including
posi-tivity for myogenin, myo D1, desmin and muscle-specific actin
Genetics: alveolar rhabdomyosarcomas characteristically have
the translocation t(2;13) which results in PAX3-FKHR fusion or
t(1;13) resulting in PAX7-FKHR fusion In those patients with
metastatic disease, tumours expressing PAX3-FKHR appear to
have a poorer prognosis The embryonal variant has no specific
cytogenetic features
Ewing’s sarcoma/peripheral neuroectodermal tumour
Ewing’s sarcoma/peripheral neuroectodermal tumours are a
family of tumours with similar cell lineage and genetic
aberra-tions These tumours were previously considered separate
en-tities, but were grouped together following the discovery that
they contained identical reciprocal translocations The cell of
origin is thought to be derived from the neural crest Ewing’s
tumour is a primary sarcoma of bone lying at the most
undif-ferentiated end of the spectrum The peripheral neuroectodermal
tumours arise in soft tissues and show evidence of primitive
neuronal differentiation The presence or absence of neural
fea-tures has no prognostic significance
The tumours arise predominantly in children and young
adults, accounting for 4% of adult and childhood malignancies
There is a predilection for males Ewing’s sarcoma usually occurs
in the medullary canal of the long bones and may present with
pain, fever and a raised erythrocyte sedimentation rate;
sug-gesting an initial diagnosis of osteomyelitis Peripheral
neuro-ectodermal tumours commonly arise in the chest, abdomen,
pelvis and extremities The prognosis depends on the stage of the
disease at presentation, and the location and size of tumour
About 20% will present with metastases, with spread occurring
primarily to the lungs, pleura, other bones and bone marrow
Involvement of lymph nodes may occur, which is rare in a
sar-coma The diagnosis is made using the combination of clinical
information, radiology, histology with immunohistochemistry
and cytogenetics
Histology: the tumour comprises small round cells arranged in
sheets separated by strands of fibrous tissue Necrosis and
hae-morrhage are common and may be striking Peripheral
neuro-ectodermal tumour cells may arrange themselves around blood
vessels to form pseudorosettes and, occasionally, true
Homer-Wright rosettes are present (in keeping with neuronal
differen-tiation) Immunohistochemistry for vimentin and the cell
mem-brane protein CD99 is positive in almost all cases; neural markers
may also be expressed
Genetics: the most common cytological abnormality shared by
these tumours is the t(11;22)(q24;q12) translocation, which
re-sults in fusion of the Ewing’s sarcoma gene with the FLI-1 gene
This translocation is found in over 95% of cases in the UK
Management is a combination of surgery, radiotherapy andmulti-drug chemotherapy The 5-year survival is about 75% forpatients with localized disease
OsteosarcomaOsteosarcoma is the most common primary malignancy of bone
in children; there are under 100 new cases in the UK each year.The cell of origin is the bone-forming cell, the osteoblast Thistumour usually arises in the metaphyses of the long bones,particularly around the knee or involving the proximal humerus.Most occur sporadically, but others may be associated withinherited disorders such as the LieFraumeni syndrome; childrenwho have hereditary retinoblastoma are also at increased risk It
is more common in adolescent boys than girls, with most mours arising in the second decade It may occur following boneirradiation for other malignancies (secondary osteosarcoma) and
tu-is associated with Paget’s dtu-isease of bone in adults Typicallyosteosarcoma presents with severe, worsening bone pain with orwithout local swelling The patient may present with a patho-logical fracture Radiological appearances vary, but the usualfinding is that of a lytic and blastic lesion with destruction ofcortical bone and extension of the tumour into soft tissues Thefull extent of disease is carefully assessed by CT or magneticresonance imaging before surgery as limb-sparing techniques arebecoming routine in the UK
The tumour is sampled extensively in order to determine theimpact of preoperative chemotherapy; the extent of tumour ne-crosis is presented as a percentage and provides importantprognostic information
Histology: osteosarcoma is an aggressive tumour that usuallyshows marked pleomorphism and nuclear anaplasia The cellularmorphology may vary considerably, consisting of small cells,spindle cells, giant cells, epitheliod cells or a combination oftypes Central to the diagnosis of osteosarcoma is the identifi-cation of malignant osteoid: an amorphous, pink, extracellulardeposit (Figure 4) The amount of osteoid and the pattern in
Figure 4 Osteosarcoma (a) malignant osteoid; (b) malignant osteoblasts.
Trang 11which it is laid down vary considerably and, in cases where it is
sparse, its identification may be extremely difficult Varying
amounts of cartilage and fibrous tissue may also be present The
conventional osteosarcoma may be subdivided according to the
predominant matrix into:
osteoblastic osteosarcoma
chondroblastic osteosarcoma
fibroblastic osteosarcoma
Genetics: no single translocation or chromosomal aberration is
consistently seen in osteosarcoma Chromosomal gains are
common and a number of genes are reportedly amplified (forexample CDK4, MDM2, SAS )
Management depends on the size, location and grade of thetumour Pulmonary metastases are common at the time of pre-sentation and, even in those with apparently localized disease, thepresence of microscopic metastases is highly likely Surgicalmanagement may involve local resection (limb-sparing surgery) oramputation Chemotherapy is given pre- and sometimes post-operatively; radiotherapy may also be employed in some cases.About 50% of those with osteosarcoma are cured in the UK A
Trang 12Abdominal pain in children is common and sometimes results from
serious pathology amenable to surgical intervention Though the true
cause of many symptoms is not always determinable a diagnostic label
is often assigned The final diagnosis for many children is ‘non-specific
abdominal pain’ e an ill-understood group of conditions Acute
appendi-citis is common in children and can be life threatening; the history is short
in the majority and the diagnosis can be obvious, but when the diagnosis
is in doubt, active observation and judicious investigation are
appro-priate For children in whom appendicitis is strongly suspected, surgery
is the standard treatment though the child with an appendix mass may
be managed conservatively Adequate resuscitation and preoperative
broad-spectrum antibiotics are important for successful outcomes.
Appendicectomy can be carried out open or laparoscopically
Laparo-scopic appendicectomy is the intervention of choice where facilities and
expertise are available Operating late at night is not recommended
Com-plications of the disease include rupture with localized or generalized
peritonitis leading to intra-abdominal and pelvic abscesses, and wound
infections Rarely there may be an iatrogenic injury to the bowel or an
ap-pendix stump rupture resulting in a faecal fistula While acute
appendi-citis remains a cause of morbidity and occasionally mortality, with
timely presentation the majority of children have a good outcome.
Keywords Acute appendicitis; appendicectomy; appendix abscess;
children; laparoscopy
Children with abdominal pain account for a high proportion of all
paediatric and paediatric general surgery admissions A wide
variety of underlying diagnoses, organic and functional, may be
causative and should be kept in mind in the assessment of each
child A stepwise approach ensures that investigations and
in-terventions are appropriate, timely and effective Clinicians
should remember that a significant number of children
present-ing for an opinion will have non-specific abdominal pain (NSAP);
ultimately no cause will be found for their symptoms
Appendicitis is the most common surgical emergency in
children and young people and though it can present at any age
the majority are between 10 and 20 years of age It is less mon in pre-school children when it commonly presents atypi-cally and at an advanced stage Older children usually presentwith more classic symptoms and signs The diagnosis ofabdominal pain in adolescent girls can, however, be difficult asmenstrual and tubo-ovarian pathologies occur Establishing agood relationship with the child and parents is important tofacilitate successful evaluation
com-Aetiology and pathogenesisFor over 120 years, since Fitz’s famous paper,1the fundamentalcause of appendicitis has remained poorly understood However,the widely accepted theory is one of proximal luminal obstruc-tion of the appendix by a faecolith or inflammatory swelling Thisresults in distension and reduced blood flow to the appendix withischaemia and necrosis of the wall In early appendicitis there isacute inflammation, oedema and congestion of the appendix.Subsequently, areas of gangrene develop and appear grey orblack at operation The lumen contains infective material andthere is commonly purulent fluid in the peritoneum A distendednecrotic appendix can perforate, spilling its infective contentsinto the peritoneal cavity
The appendix usually perforates on the anti-mesenteric borderand may present with localized or generalized peritonitisdepending on whether the inflammation is well contained or not
An inflammatory appendix mass made up of small bowel andomentum can form around a perforated appendix
Anorexia or nausea are common features of acute citis Vomiting, if present, is usually non-bilious initially Aninflamed pelvic appendix may induce small-volume but frequentstools that can be confused with the diarrhoea associated withgastroenteritis A history of recent illness and medication, espe-cially pain killers and antibiotics, is important Specific questionsregarding respiratory and ear, nose and throat symptoms should
appendi-be sought If symptoms have appendi-been present for over 4 days theabdominal examination should include careful palpation for anappendix mass
SignsOverall assessment should include weight, height and generalinspection, looking to exclude stigmata of chronic ill health.Observing the child walking and getting onto the examinationcouch can alert the examiner to the presence of peritonitis Thepatient who can jump up and down without obvious discomfort
is unlikely to have appendicitis, and some use this as a test tohelp assess the less ill patient Low-grade pyrexia is usuallypresent in the range 37.4e38.5C Temperatures above 39C may
Aly Shalaby MRCS is a Specialist Registrar in the Department of
Paediatric Surgery, King’s College Hospital, London, UK Conflicts of
interest: none declared.
Niyi Ade-Ajayi MPhil FRCS(I) FRCS(Paed) is a Consultant Paediatric Surgeon
at King’s College Hospital, London, UK Conflicts of interest: none
declared.
Trang 13be secondary to viral illness, urinary tract infections or
perfora-tion of the appendix with generalized peritonitis Assessment of
hydration helps to inform the initial fluid resuscitation and the
urine specific gravity is a useful measure that is often overlooked
The tongue is inspected and the pulse taken when the child is
settled
A furred tongue and a bounding pulse are typical of
appen-dicitis The chest is inspected and careful auscultation carried out
to look for evidence of chest infection since a lower lobe
pneu-monia can present with abdominal pain The ears and throat are
examined for otitis media and tonsillitis, respectively Abdominal
examination includes looking for the point of maximal
tender-ness and signs of peritonitis; often maximum tendertender-ness is
directly over the appendix Significant faecal loading associated
with constipation should be excluded though rectal examination
is usually unnecessary The groins should be checked, looking
for hernias and, in boys, the scrotum should be examined The
renal angles should be palpated for tenderness The differential
diagnoses for abdominal pain in children appears inTable 1
Investigations
Accurate history and clinical examination are often all that are
required to diagnose or rule out appendicitis A urine sample for
a dipstick test is usually taken when the child arrives at the
hospital and this is a sensitive test for urinary tract infection If
positive, the urine should be sent for microscopy and culture
The urine specific gravity gives a guide to hydration (1.030 dry,
1.010 well hydrated) Serum white cell count may support
clin-ical suspicion However, an elevated white cell count should not
be the primary indication for appendicectomy Other useful
blood tests include serum amylase and C-reactive protein (CRP)
The former is done to rule out pancreatitis and the latter to
confirm the clinical suspicion of an active inflammatory process.Plain abdominal radiography is occasionally indicated if there is
a history suggestive of urinary calculi A plain X-ray may revealcalculi in the urinary tract A faecolith in the right iliac fossa may
be seen with appendicitis Widespread faecal loading may vide an alternative explanation for pain but remember thatconstipation does not cause fever or right iliac fossa tenderness.Abdominal ultrasound (US) may help when the diagnosis isequivocal; this is especially useful in adolescent girls to rule outtubo-ovarian pathology When an appendix mass is palpated, USmay provide useful information about the size, content (smallbowel, omentum and appendix) and whether there is pus withinthe mass that might require drainage Some centres advocatefast, high-resolution computed tomography (CT) scans for thispurpose and for establishing the diagnosis in doubtful cases (e.g.typhlitis, Crohn’s disease, pancreatitis); however, in the UK, theradiation dose is considered justifiable only for a small number ofchildren In 2004, a survey of the management of appendicitis inthe US reported that the majority of paediatric surgeons preferred
pro-CT scans as part of their preoperative workup.2A contemporaryreport demonstrated no decrease in negative appendicectomyrates using CT.3Several studies from the USA have questionedits value noting the radiation risk UK paediatric surgeons have
a preference for US compared to CT Although US is operatordependent, it is readily available, repeatable and does notexpose the child to ionizing radiation
Some children have a long history of recurrent, significantabdominal pain Signs may be few and initial investigationsnegative This sub-group of patients warrant additional investi-gation which may include flexible and capsule endoscopy and aMeckel scan If these investigations are negative a proportionmay benefit from diagnostic laparoscopy.4A comprehensive re-view of chronic abdominal pain (CAP) in children was recentlypublished by Wright et al.5
ManagementFollowing initial clinical assessment, the child is put into one ofthree categories: has not got appendicitis, has got appendicitis, oruncertain If the patient has no significant symptoms or signs of
an acute abdomen, and the social setting is appropriate, they can
be discharged with advice to return if there is persistence orworsening of the condition If appendicitis is likely, preparationfor surgery should commence with fluid resuscitation andintravenous antibiotics
The timing of surgery is also important Fitz1and McBurney6advocated early surgery but morbidity was high Antibioticsdramatically changed the outlook and current recommenda-tions from both the UK and the USA is to perform the surgery indaylight hours after antibiotics and fluids have been given.Emergency surgery late at night or in the early hours of themorning, in a child that has not been fully resuscitated, is rarelyindicated If this is thought to be necessary senior consultation
is mandatory and access to intensive care is likely to be needed
In situations where the symptoms are significant but thediagnosis is doubtful, the child should be admitted for activeobservation and possibly, further investigation.7 Antibioticsshould not be commenced The child’s vital signs should bemonitored at regular intervals Regular surgical evaluation
Age-dependent differential diagnoses in children
presenting with abdominal pain to hospital
Pre-school Older child Adolescent
Acute appendicitis Acute appendicitis Acute appendicitis
Gastroenteritis Gastroenteritis Gastroenteritis
Urinary tract
infection
Urinary tract infection
Urinary tract infection Respiratory tract
infection
Respiratory tract infection
Respiratory tract infection Henoch eSchonlein
purpura
Henoch eSchonlein purpura
Henoch eSchonlein purpura
Constipation Constipation Acute scrotum
Intussusception Meckel’s diverticulitis Ovarian pathology
Non-specific abdominal pain
Fallopian tube pathology Acute scrotum Inflammatory bowel
disease Non-specific abdominal pain Pancreatitis Renal stones Table 1
Trang 14should be carried out by appropriately experienced clinicians.
When possible, the review team should include the admitting
surgeon During this period the child is given analgesia as
required and is allowed only clear fluids by mouth to avoid
de-lays in transfer to theatre if required Appendicitis is an evolving
process and if the diagnosis is unclear when the child is first
seen, it may be diagnosed with active observation The decision
to proceed to appendicectomy is based principally on finding
persistent guarding in the right iliac fossa If the pain andtenderness resolve spontaneously during active observation, thechild is discharged In adult and paediatric practice, high nega-tive appendicectomy rates were previously considered as anacceptable alternative to delayed diagnosis Active observationand selective investigation reduces the number of negative ap-pendicectomies However, it is interesting that most childrenwho have an apparently normal appendix removed in this situ-ation are cured of their pain
Despite awareness of the dangers of appendicitis and
continue to see advanced appendicitis when the diagnosis mighthave been made earlier
The treatment options for acute appendicitis and an appendixmass have continued to evolve and, increasingly are tailored tothe patient’s age and the diagnostic findings.Figure 1 summa-rizes our management strategy for children presenting to hospitalwith acute abdominal pain
Surgery
An older child or adolescent who requires surgery may besafely managed in a district hospital under the care of an adultgeneral surgeon with paediatric input Infants and toddlersshould be stabilized and discussed with a paediatric surgeryunit, with a view to transfer Fluid resuscitation is based onthe estimated deficit and is distinguished from maintenance
co-amoxiclav where the clavulanate component extends thespectrum of amoxicillin to Gram-negative and anaerobic cover.For complicated appendicitis we add in gentamicin to enhanceGram-negative cover and metronidazole to improve anaerobiccover A general anaesthetic with muscle relaxant is adminis-tered by a paediatric anaesthetist Appendicectomy can be open
or laparoscopic Open surgery is carried out via a right lowerquadrant transverse (Lanz) incision The external oblique
Abdominal pain
Not appendicitis
e.g Constipation –treat and discharge
Symptoms &
signs resolveNSAP
LA, laparoscopic appendicectomy; NSAP, non-specific abdominal pain.
Medicalproblem
Resuscitationand antibiotics
Active observationand investigations
Discharge Refer to
paediatrician
Appendicitissuspected
DischargeLA
Management of acute abdominal pain in children
Figure 1
Figure 2 Representation of theatre layout for laparoscopic
appendicec-tomy AS, Anaesthetic stack; AN, anaesthetist; ES, energy source; LS,
laparoscopic stack; SA, surgical assistant; S, surgeon; SN, scrub nurse; LT,
laparoscopic tray.
Trang 15muscle is cut then split along its fibres The internal oblique
and transversus muscles are also split along their fibres and the
peritoneum is opened Fluid is sent for microbiology The
caecum is identified and the appendix isolated and
devascu-larized The base of the appendix is crushed using artery
forceps prior to ligation and removal Burying the stump using
a circumferential absorbable suture is recommended
Laparoscopic appendicectomy is now the preferred approachfor most paediatric surgeons.Figure 2 shows the theatre layoutand Figure 3 shows port positions for laparoscopicappendicectomy
A 5e12-mm umbilical port for the camera, inserted by theHasson technique is favoured Two 5-mm ports are sited low inthe left iliac fossa and bowel-holding forceps inserted for initialexploration Samples of intraperitoneal fluid are taken for cultureand antibiotic sensitivity using a suction device attached to atrap The appendix is identified, mobilized and devascularizedusing bowel-handling forceps and a hook diathermy Three pre-formed loops of absorbable suture material are placed around theappendix: two just distal to the origin of the appendix from thecaecum, and the third further along the appendix allowing suf-ficient room for the appendix to be cut between loops If exten-sive peritoneal contamination is present, a thorough washoutwith saline at the end of the procedure is required to decrease therisk of abscess formation
This standard three-port approach can be abbreviated to twoports if one of the instruments is used in parallel to a roticulatingscope Single-port appendicectomy is slowly gaining popularitybut is currently limited to older children.Figures 4and5are anexample of a single-port device used by the authors
A preoperatively diagnosed appendix abscess larger than 3 cm(Figure 6) is amenable to percutaneous drainage Drainage
Figure 3 Port site placement for laparoscopic appendicectomy X, 5 e12
mm-port placed by Hasson technique for camera; Y and Z, 5-mm ports
placed for instruments.
Figure 4 Components of the GelPointRAdvanced Access Platform, for single-port laparoscopy Image courtesy of Applied Medical Resources Corporation, Rancho Santa Margarita, CA, USA.
Trang 16should be followed by a course of antibiotics Percutaneous
drainage has its risks8and may not always be possible if there
are intervening abdominal viscera A randomized controlled
study showed no difference between immediate and interval
appendicectomy for an appendix abscess.9
The management of an appendix mass is controversial and
each case should be judged on merit A mass demonstrated
during initial assessment is conventionally treated with
intrave-nous antibiotics and fluids and an interval appendicectomy, 6
weeks after the acute admission, should be considered.10
Addi-tional controversies exist with regards to an appendix mass
identified only under anaesthetic Some surgeons have the child
woken up and then treated conventionally Faced with this
sce-nario and a short history, the authors proceed with a
laparo-scopic appendicectomy and convert to open surgery if the
procedure is deemed unduly challenging The approach of the
authors is summarized inFigure 7
Interval appendicectomy after successful management of
either an appendix mass or an appendix abscess should be
dis-cussed with the patient and parents The risk of recurrent
appendicitis has been estimated anywhere between 15% and
25% whilst the complications of interval appendicectomy
include wound infection, ileus, haematoma and bowel
obstruc-tion have been reported as 3.4%.11
HistologyThe appendix is sent for histological examination and reviewed
by the surgeon In uncomplicated appendicitis this usually showssubmucosal or transmural neutrophil infiltration Intraluminalworms such as Enterobius vermicularis (pinworms) are some-times found and arrangements should be made for anti-helminthics for the child and close contacts Unusual histologysuch as a carcinoid tumour may occasionally be found Tumours
2 cm or smaller are cured by an appendicectomy Further ment of larger tumours is controversial due to lack of evidence;however traditional teaching is to perform a right hemi-colectomy along with the resection of the regional mesentericlymph nodes
treat-ComplicationsMeticulous surgical technique including gentle tissue handlingshould reduce intraoperative complications such as bowelperforation and ureteric injury Early postoperative complica-tions include abscess formation (around 2%) which may betreated with antibiotics or percutaneous image-guided drainage.Other complications include adhesive bowel obstruction which ismore common if the appendix was perforated Recurrentappendicitis has also been reported in cases where a long ap-pendix stump was left behind
PrognosisMortality following appendicitis in childhood is rare in the UK.The case fatality rate fell from 1.06 to 0.16 per 1000 discharges inthe 30 years to 1997 Earlier presentation and improved clinicaldiagnosis are likely to have been important contributors to thisreduction, as are an increased availability of specialist paediatricmedical, anaesthetic and surgical services Morbidity resultsfrom delayed presentation for a medical opinion or referral aswell as inadequate pre-operative preparation and poor surgicaltechnique Overall, however, children with acute appendicitismanaged in appropriately resourced units generally recover with
Figure 5 Three-dimensional rendering of the assembled GelPoint R for
single-port laparoscopy Image courtesy of Applied Medical Resources
Corporation, Rancho Santa Margarita, CA, USA.
Figure 6 Computed tomography scan showing an intra-abdominal abscess secondary to appendicitis.
Trang 171 Fitz RH Perforating inflammation of the vermiform appendix, with
special reference to its early diagnosis and treatment Trans Assoc
Am Physicians 1886; 1: 107 e36
2 Muehlstedt SG, Pham TQ, Schmeling DJ The management of pediatric
appendicitis: a survey of North American Pediatric Surgeons J Pediatr
Surg 2004; 39: 875 e9
3 Martin AE, Vollman D, Adler B, Caniano DA CT scans may not
reduce the negative appendectomy rate in children J Pediatr Surg
2004; 39: 886 e90
4 Kolts RL, Nelson RS, Park R, Heikenen J Exploratory laparoscopy for
recurrent right lower quadrant pain in a pediatric population Pediatr
Surg Int 2006; 22: 247 e9
5 Wright NJ, Hammond PJ, Curry JI Chronic abdominal pain in children:
help in spotting the organic diagnosis Arch Dis Child Educ Pract Ed
J Pediatr Surg 2008; 43: 977 e80
9 St Peter SD, Aguayo P, Fraser JD, et al Initial laparoscopic dectomy versus initial nonoperative management and interval ap- pendectomy for perforated appendicitis with abscess: a prospective, randomized trial J Pediatr Surg 2010; 45: 236 e40
appen-10 Gillick J, Velayudham M, Puri P Conservative management of appendix mass in children Br J Surg 2001; 88: 1539 e42
11 Hall NJ, Jones CE, Eaton S, Stanton MP, Burge DM Is interval cectomy justified after successful nonoperative treatment of an appendix mass in children? A systematic review J Pediatr Surg 2011; 46: 767 e71
appendi-Appendix mass
Abdominal US
Diagnosed preoperativelyDiagnosed after anaesthesia
Shorthistory
Shorthistory
LA, laparoscopic appendicectomy; US, ultrasound
Longhistory
Treat with antibiotics6–8 -week
interval
If difficult
Image-guidedpercutaneous drain
Wakepatient up
Trang 18Gastro-oesophageal reflux occurring infrequently and without symptoms
or occurring without damage to the oesophagus is not considered
path-ological, otherwise the reflux and the pathology are referred to as
gastro-oesophageal reflux disease (GORD) Factors predisposing to GORD
include: impairments to the physiological antireflux barrier and
anatom-ical abnormalities of the oesophagus or diaphragm Non-operative and
medical management result in resolution of symptoms in the majority
of children Surgery is indicated in the event of failure of medical
manage-ment or severe complications and in neurologically normal children this
would usually be a laparoscopic or open fundoplication In severely
neurologically impaired children other options are sometimes considered
and these include: fundoplication with or without vagotomy and
pyloro-plasty; surgical feeding jejunostomy and oesophago-gastric dissociation.
Keywords Antireflux procedure; fundoplication; gastro-oesophageal
reflux; non-bilious vomiting
Definition and epidemiology
Gastro-oesophageal reflux (GOR) is the passage of gastric
con-tents into the oesophagus associated with or without
regurgita-tion or vomiting Gastro-oesophageal reflux disease (GORD) is
defined as the presence of GOR with symptoms or complications
A recent Italian population study reported a prevalence of 12%
for GOR in infants
Aetiology
The process of swallowing involves the onset of oesophageal
peristaltic waves and associated relaxation of the upper and
lower oesophageal sphincters These are regulated by the vagus
and sympathetic nerves through the intrinsic neural network of
the oesophagus In GOR, non-deglutatory peristaltic waves are
triggered to achieve clearance The factors promoting GOR are
increased intra-abdominal pressure, strong gastric contractions,
reverse gastric peristalsis, negative pressure in the oesophagusduring inspiration and sometimes the lying down position.The physiological antireflux barrier (Figure 1) is made up ofthe following:
The lower oesophageal sphincter (LOS) composed of:
the inner circular smooth muscle layer of oesophagus
high normal resting tone of the lower oesophagus whichrelaxes only during swallowing
The flutter valve formed by the mucosal fold below theLOS
The diaphragmatic crural sling composed of striatedmuscle which contracts rhythmically during the respira-tory cycle and displaces the gastro-oesophageal junctiondownwards, closing it tightly during inspiration andforming an external pinchcock mechanism
There are several other minor components protecting againstGOR including increased intra-abdominal oesophageal pressure,the angle of His, alkaline saliva in the oesophagus bufferinggastric acid, and protective mucus
Anatomical disruption (e.g hiatus hernia, congenital phragmatic hernia, oesophageal atresia) or functional abolition(neurological disorders) of one or more of the protective mech-anisms result in GOR The occurrence of non-deglutatory tran-sient lower oesophageal sphincteric relaxation accounts for mostepisodes of GOR
dia-Clinical presentationMost infants with GORD present with varying degrees of non-bilious vomiting or discomfort following feeds Ear, nose andthroat (ENT) symptoms including recurrent tonsillitis, otitis andlaryngeal polyps are less commonly reported Infants with severeGORD can present with complications including apparent life-threatening events (ALTE), aspiration pneumonia, chronic cough
or recurrent wheeze Severe GORD rarely results in nutritionaldeficiencies and failure to thrive and paradoxically children can
be overweight because they can consume inappropriate ties of milk if this relieves symptoms Older children tend topresent with heartburn and dysphagia especially when the GORDhas resulted in a stricture A stricture may also present with foodbolus obstruction or oesophageal regurgitation which can bedistinguished from vomiting as the food is often unaltered.Oesophagitis can cause pain, iron deficiency anaemia and blood
quanti-in the vomit Sandifer syndrome is seen chronic reflux, and ischaracterized by dystonic body movements or spastic torticollis.Aspiration of gastric contents into the respiratory tract can result
in bronchospasm, recurrent lower respiratory infections andatelectasis Cases of sudden death have also been reported Long-term risks of GORD include oesophageal strictures, Barrett’soesophagus and an increased risk of oesophageal carcinoma
Investigations
In a recent survey of American paediatric surgeons, most geons reported that their decision to proceed to an antirefluxprocedure was based mainly on the clinical history from parentsthan on investigations demonstrating GORD There is no singleinvestigation which predicts response to medical or surgicaltherapy
sur-Dhanya Mullassery MRCS PhD is a Specialty Trainee in Paediatric Surgery
at Alder Hey Children’s Hospital, Liverpool, UK Conflicts of interest:
none declared.
Matthew O Jones MD FRCS (Paed) is a Consultant in Paediatric Surgery at
Alder Hey Children’s Hospital, Liverpool, UK Conflicts of interest: none
declared.
Trang 19Upper gastrointestinal contrast studies may be used to
delin-eate the anatomy of LOS and rule out a hiatus hernia GOR can be
classified on contrast swallow examination as followse grade 1
(reflux into distal oesophagus); grade 2 (reflux into proximal
thoracic oesophagus); grade 3 (reflux into cervical oesophagus);
grade 4 (continuous reflux) and grade 5 (aspiration into
respi-ratory tract) Figure 2 shows an upper gastrointestinal (GI)
contrast swallow demonstrating severe GOR However, routine
contrast studies are not recommended due to the high
false-positive and -negative rates and also the associated risk of
radiation Contrast studies can rule out other causes of
vomiting such as malrotation and gastric or bowel obstruction
Twenty-four-hour pH studies help quantify aspects of acid
reflux The number of acid reflux episodes, their duration and
timing in relation to activities can be recorded A reflux index is
defined as the percentage of time the measured oesophageal pH
is less than 4 If this is above 5% of the time it is considered
abnormal This measure alone does not correlate well with the
severity of symptoms in infants This discrepancy may be due to
the buffering of gastric acid by milk feeds Both the North
American and European Societies for Pediatric Gastroenterology
and Nutrition have made specific recommendations for the
in-dications for the use of oesophageal pH monitoring in children
changes in electrical resistance between multiple electrodes
placed along the oesophagus and can be used to calculate the
direction and velocity of bolus movements in the oesophagus
This has the advantage of being able to detect not only
oeso-phageal acid exposure but also neutral or even alkaline reflux
events which are more common in newborns MII with pH
motoring has been shown to double the probability of
compared to pH monitoring alone in infants
Upper GI endoscopy is used to assess oesophagitis secondary to
reflux Endoscopically oesophagitis is classified by the Savary
Miller scoring system as grade 1 (erythema of mucosa), grade 2
(linear non circular ulceration) grade 3 (confluent ulceration) and
grade 4 (stricture) A negative endoscopic examination, however,does not exclude GORD in infants or patients on H2blockers orproton pump inhibitor (PPI) treatments Endoscopic biopsy helps
to rule out other causes of oesophagitis and to diagnose andmonitor Barrett’s oesophagus
Oesophageal manometry is sometimes used in older children
to assess the function of the LOS However, non-deglutatory laxations are difficult to record accurately
re-It is noteworthy that in many neurologically disabled patients,objective evidence of GORD is sometimes absent even in thepresence of marked symptoms This suggests that, in these pa-tients, the condition is more than mere ‘acid reflux’, and may becompounded by inappropriate neurological responses Disor-dered physiological responses have been demonstrated byelectro-gastrographic and gastric emptying studies
ManagementMost neonates have GOR which resolves spontaneously by theage of 18 months Infants with GORD are initially managed usingconservative measures Thickened feeds reduces regurgitationbut does not always decrease the frequency of reflux episodes.Raising the head of the bed has not been shown to have abeneficial effect in infants with GOR Whereas prone or a left-sided sleeping position with elevation of the bed has been shown
to be of benefit in adults with GOR
H2 receptor antagonists (ranitidine) help in symptomaticimprovement of GORD, but tolerance can be a problem PPIsinactivate the HþKþadenosine triphosphatase (ATPase) pumpand are currently the medical treatment of choice for symptoms
of GORD and oesophagitis Complications of PPIs include anincreased risk of community-acquired pneumonias especially inimmunocompromised children However, the evidence does notsupport the use of PPIs in infants Recent studies suggest a po-tential role for baclofen in inhibiting LOS relaxation Motilityagents such as domperidone are widely used although random-ized controlled trials do not support their use
Diaphragmaticcrus
Figure 2 Contrast swallow demonstrating severe gastro-oesophageal reflux.
Trang 20Surgical management
Surgery for GORD is indicated when there has been an
inade-quate response to medical management or the presence of
sig-nificant or recurrent respiratory complications Surgery may be
considered early in children with neurological impairment and
those with anatomical factors contributing to GORD (e.g
oeso-phageal atresia, congenital diaphragmatic hernia) The aim of
antireflux surgery is to reconstruct an effective antireflux barrier
maintaining the free passage of food through the
gastro-oesophageal junction The most common procedure is a
fundo-plication, which decreases reflux by increasing the LOS pressure,
relaxations
The loose Nissen fundoplication is illustrated inFigure 3 This
entails a 360-degree wrap of gastric fundus around the lower
oesophagus that acts as an effective pneumohydraulic valve The
procedure involves mobilization of the upper third to half of the
greater curvature with or without division or ligation of short
gastric vessels This is followed by mobilization of the abdominal
oesophagus to enable encircling of the fundus around the
oesophagus above the left gastric vessels A single or double
layer of braided non-absorbable sutures are used A long wrap or
a tight wrap can result in gas bloat (air trapping in the stomach)
and dysphagia The fundoplication is combined with
approxi-mation of the crura if needed and always if there is a hiatus
hernia to repair
Laparoscopic fundoplication is being increasingly performed
with short term success rates similar to the open procedure and
the advantages of shorter postoperative stay and lesser analgesic
requirements Long-term results from randomized controlled
trials are awaited
Anterior (Thal) or posterior (Toupet) wraps of 180-degrees are
preferred by some surgeons for fundoplication in patients who
have had repair of oesophageal atresia to avoid dysphagia in the
context of poor oesophageal motility
In children with neurological disorders, delayed gastric
emptying, spasticity and retching contribute to the severity of
symptoms and Nissen fundoplication alone (whether open or
laparoscopic) often achieves only modest symptomatic relief,whereas fundoplication combined with vagotomy and pylo-roplasty results in both a better functional outcome and a lowerrate of subsequent revision Since most children in this grouphave difficulty feeding by mouth, they also tend to have a feedinggastrostomy
An alternative to fundoplication and feeding gastrostomy inchildren with neurological impairment is to form a surgicaljejunostomy for feeding to reduce reflux episodes whileproviding nutrition The main long-term complication of a sur-gical feeding jejunostomy is volvulus of the jejunal limb.Children with severe neurological impairment who fail torespond to the above procedures may be considered for anoesophago-gastric dissociation with a Roux-en-Y feeding jeju-nostomy (Figure 4) This technically demanding procedure may
be complicated by gas accumulating within the distal bowel,presumably because the rearranged anatomy precludes theregurgitation of swallowed gas, and so caution is advised inchildren with poor colonic motility
Recent advances in endoscopy have introduced new reflux procedures including endoluminal fundoplication, radio-frequency application to the oesophago-gastric junction and in-jection of an inert material at the LOS reducing its distensibility.Outcomes
anti-A recent systematic review reported a median success rate of 86%(57e100%) for antireflux surgery in children with GORD Similarrecurrence rates have been reported for open and laparoscopicfundoplication The failure rates after redo fundoplication havebeen reported to be between 7% and 26% The risk factors forrecurrence are younger age and co-morbidities including neuro-logical impairment A recent randomized controlled trial in adultsreported the use of antireflux medications in 44% of patients 5years following laparoscopic fundoplication
Dysphagia can result when the wrap is too long or too tight Arecent randomized controlled trial comparing laparoscopic
Oesophagus
Fundus wrapapproximated usingnon-absorbable sutures
Trang 21Nissen and Thal fundoplications reported a significantly lower
rate of recurrence for Nissen procedure but with a higher rate of
dysphagia in neurologically normal children Other early
post-operative complications include oesophageal perforation,
pneu-monia and wound infection Gas bloat can also result from a tight
wrap Dumping has been reported following fundoplication
especially when performed with a pyloroplasty
Children with neurological problems have the highest risk of
postoperative complications including wrap failure, respiratory
complications and death Wrap failure has been reported in 20
e50% of neurologically impaired children Antireflux surgery
has been shown to reduce significant respiratory events causing
hospital admissions in neurologically impaired children under 4
years of age but not in older children
Conclusions
GOR is common in neonates and spontaneously settles in the
majority after infancy The diagnosis of GORD is mainly based on
the history with supportive investigations in selected patients
Surgery is indicated for those who fail to respond to medical
management and for complications The surgical
armamen-tarium of antireflux surgery includes fundoplication, feeding
jejunostomy and oesophago-gastric dissociation The outcomes
of surgery are variable and failure rates and complications are
FURTHER READING
Campanozzi A, Boccia G, Pensabene L, et al Prevalence and natural
history of gastroesophageal reflux: pediatric prospective survey.
Pediatrics 2009; 123: 779 e83
Craig WR, Hanlon-Dearman A, Sinclair C, et al Metoclopramide, thickened feedings, and positioning for gastro-oesophageal reflux in children under two years Cochrane Database Syst Rev 2004; 4: CD003502 Fonkalsrud EW, Ament ME, Berquist W Surgical management of the gastroesophageal reflux syndrome in childhood Surgery 1985; 97: 42 e8
Jeurnink SM, van Herwaarden-Lindeboom MY, Siersema PD, et al Barrett’s esophagus in children: does it need more attention? Dig Liver Dis 2011; 43: 682 e7
Lall A, Morabito A, Dall’Oglio L, et al Total oesophagogastric dissociation: experience in 2 centres J Pediatr Surg 2006; 41: 342 e6
Mauritz FA, van Herwaarden-Lindeboom MY, Stomp W, et al The effects and efficacy of antireflux surgery in children with gastroesophageal reflux disease: a systematic review J Gastrointest Surg 2011; 15:
1872 e8 Srivastava R, Berry JG, Hall M, et al Reflux related hospital admissions after fundoplication in children with neurological impairment: retro- spective cohort study Br Med J 2009; 339: b4411
Vandenplas Y, Rudolph CD, Di Lorenzo C, et al North American Society for Pediatric Gastroenterology Hepatology and Nutrition, European Soci- ety for Pediatric Gastroenterology Hepatology and Nutrition Pediatric gastroesophageal reflux clinical practice guidelines: joint recommen- dations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN).
J Pediatr Gastroenterol Nutr 2009; 49: 498 e547 Williams AR, Borsellino A, Sugarman ID, Crabbe DC Roux-en-Y feeding jejunostomy in infants and children Eur J Pediatr Surg 2007; 17: 29 e33
Wockenforth R, Gillespie CS, Jaffray B Survival of children following Nissen fundoplication Br J Surg 2011; 98: 680 e5
Trang 22Oesophageal atresia
Gareth P Hosie
Elizabeth Gavens
Abstract
Oesophageal atresia is a congenital malformation that affects
approxi-mately 1 in 4000 newborn infants It is most commonly associated with
a distal tracheo-oesophageal fistula It can also be associated with
verte-bral anomalies, anorectal malformation, cardiac defects, renal and limb
anomalies It requires surgery, usually within the first day of life to correct
the anomaly and establish continuity of the gastrointestinal tract.
Keywords Congenital anomaly; gastro-oesophageal reflux; neonate;
oesophagus; paediatric surgery
Background
Oesophageal atresia (OA) is a congenital anomaly in which a
variable portion of the oesophagus is not formed The
com-monest configuration is a blind-ending upper oesophageal
pouch, with a distal tracheo-oesophageal fistula (TOF)
connect-ing the lower oesophagus to the trachea Oesophageal atresia
requires surgery to correct the anomaly and this is usually
per-formed within the first 24e36 hours of life
The incidence varies globally, but is between 1 in 2500 and 1
in 4000 births There is no gender predominance and there has
currently been no common genetic anomaly identified, although
siblings of a child with oesophageal atresia have a 1e2%
inci-dence One-third of infants with oesophageal atresia are born
prematurely The condition itself does not have a high mortality
and infants who die with oesophageal atresia usually do so from
associated, usually cardiac, conditions
Embryology
The oesophagus is derived from the primitive foregut by day 20
of gestation The respiratory tract forms by day 26 from a groove
on the ventral aspect of the foregut Over the next 2 days the
trachea and bronchial tree develop as tubular structures separate
from the oesophagus This occurs as a result of the development
of tracheo-oesophageal folds that fuse together to form the
tracheo-oesophageal septum separating the ventral trachea from
the dorsal oesophagus The stimulus for this separation of the
gastrointestinal and respiratory tract is not fully understood, but
it is disruption of this process that results in oesophageal atresia
in its many forms
ClassificationOesophageal atresia presents anatomically with a variety ofconfigurations By far the commonest type is the presence of ablind-ending proximal oesophagus, with the distal oesophagusattached to the trachea in the form of a tracheo-oesophagealfistula (Figure 1, Type C) Oesophageal atresia can also occur inthe absence of a TOF when it is known as a pure oesophagealatresia (Figure 1a, Type A)
Associated anomaliesThere are a number of anomalies associated with oesophagealatresia and the majority of patients have one of more of theseanomalies The frequency of occurrence of these associations is
so common, that there are a number of named associations, themost common being VACTERL association (Box 1) An associa-tion is the non-random occurrence of a group of anomalieswithout a known common aetiological factor This is distinctfrom a syndrome, which is the occurrence of a group of anom-alies due to a single (often genetic) aetiology
DiagnosisMost infants with oesophageal atresia are diagnosed postnatallywithin the first few hours of life Some are suspected antenatallywhen there is polyhydramnios and a small or ‘absent’ stomach onultrasound scanning (USS) If there are antenatal suspicions theparents should undergo antenatal counselling including the dis-cussion of associated anomalies Any newborn whose mother hadpolyhydramnios during pregnancy should have a naso-gastric tube(NGT) passed to exclude the diagnosis of oesophageal atresia.Postnatally, oesophageal atresia is usually suspected when aninfant is drooling and unable to swallow saliva Attempts atfeeding lead to spluttering, coughing and can cause aspirationand cyanosis Attempts to pass a nasogastric tube are unsuc-cessful as resistance is felt, usually at about 10 cm from the lips,when the tube hits the bottom of the oesophageal pouch.Once suspected a chest radiograph with a tube in the upperpouch confirms the diagnosis The tube should be a large tube,around a size 10 Fr and gentle pressure should ideally be placed
on the tube during the X-ray examination If there is an phageal atresia, this will show the NGT curling in the pouch(Figure 2) If there is an associated distal tracheo-oesophagealfistula this will show air in the stomach and distal bowel If there
oeso-is a pure oesophageal atresia there will be no air in the stomach.Infants who have been diagnosed with oesophageal atresiarequire an echocardiogram, USS examination of the renal tractand a full spinal X-ray
Initial managementInfants with oesophageal atresia should undergo a full baby check
to look for any other associated anomaly The infant should bekept warm and receive maintenance fluids A double bore tubecalled a Replogle tube should also be passed via the nostril into theoesophageal pouch This enables aspiration of saliva and secre-tions The Replogle tube is a sump drain and the presence of the
Gareth P Hosie MBChB FRCS(Paed) is a Consultant Paediatric Surgeon at
the Royal Victoria Infirmary, Newcastle-upon-Tyne, UK Conflicts of
interest: none.
Elizabeth Gavens BM BS BMed Sci MRCS is a Specialist Trainee in Paediatric
Surgery at the Royal Victoria Infirmary, Newcastle-upon-Tyne, UK.
Conflicts of interest: none.
Trang 23second lumen allows continuous suction on the tube and for the
tube to be flushed and therefore unblocked if necessary
Surgery
Oesophageal atresia requires surgical correction, usually with the
first 24 hours of life If possible this should be carried out during
usual working hours rather than out of hours Infants with
associated duodenal atresia, progressive abdominal distension,
or who require positive pressure ventilation should undergo
emergency surgery and not be left overnight The major risk of
positive pressure ventilation is that gas passes through the fistula
and distends the abdomen and so impairs ventilation Gastricperforation can occur The need for ventilation is most common
in premature babies In such compromised babies, particularlythose under 1.5 kg, an emergency ligation of the TOF alone can
be a lifesaving procedure and the anastomosis can be fashioned
at a second operation
Bronchoscopy is useful at the beginning of the procedure toconfirm the position of the distal tracheo-oesophageal fistula(Figure 3) This is also useful to rule out a rare proximal fistula tothe upper pouch or a cleft of the larynx The anaesthetist aims toplace the tip of the endotracheal tube beyond the tracheo-oeso-phageal fistula, as this limits gas flow into the stomach For thesame reason ventilation is ideally administered without paralysisfor as long as possible
The repair can be performed either thoracoscopically orthrough a right thoracotomy The thoracotomy is performedthrough a right infrascapular incision (Figure 4)
The thoracic cavity is entered at the fourth intercostal spaceand an extra-pleural approach is maintained by sweeping theparietal pleura off the chest wall The azygous vein is identifiedand ligated before division This will allow identification of thedistal oesophagus joining the trachea at the tracheo-oesophagealfistula The fistula is then divided, repairing the tracheal wallwith non-absorbable sutures The proximal oesophagus is thenidentified at the thoracic inlet by asking the anaesthetist to push
Anatomical classification of oesophageal atresia
Type A – Oesophageal atresia without
fistula or so-called pure oesophageal
Type D – Oesophageal atresia with
proximal and distal TOFs (<1%)
Type E – TOF without oesophageal atresia or so-called H-type fistula (4%)
Type F – Congenital oesophageal stenosis (<1%)
Figure 1
VACTERL association
V e Vertebral Multiple/single hemivertebrae, scoliosis, rib
anomalies
A e Anorectal e Imperforate anus
C e Cardiac Most commonly ventricular septal defect (VSD)
T e Trachea Tracheo-oesophageal fistula
E e Oesophageal
R e Renal tract anomalies
L e Limb anomalies (radial or tibial)
Box 1
619 Ó 2013 Published by Elsevier Ltd All rights reserved.
Trang 24down on a tube in the lumen of the proximal oesophageal pouch.
This pouch must be mobilized sufficiently to enable an
anasto-mosis with the distal oesophagus Excessive mobilization of the
distal oesophagus should be avoided as this structure receives a
segmented blood supply which can be disrupted by excessive
dissection The anastomosis is performed using interrupted
absorbable 5.0 sutures A trans-anastomotic tube is often passed
prior to the completion of the anastomosis The tube, will allow
early enteral feeding beyond the anastomosis A chest drain is
inserted with only if there is anxiety about the security of the
anastomosis
Surgical management of anatomical variants
H-type tracheo-oesophageal fistula
This fistula often has a cervical rather than intra-thoracic
loca-tion It is useful to perform a bronchoscopy and pass a soft wire
through the fistula from the trachea to the oesophagus An
oesophagoscopy is then undertaken and the end of the wire
brought out through the mouth The surgical approach is through
a right cervical incision and the fistula can be identified by
applying traction to the wire Once identified the fistula is dividedand the tracheal and oesophageal walls repaired
Pure oesophageal atresia
In this condition there is a long gap between the upper phageal pouch and the distal oesophagus which means that thetwo ends cannot be primarily brought together The commonestapproach is to undertake an initial gastrostomy to enable theinfant to feed enterally, and wait for the child to grow for 2e3months, after which the comparative length of the oesophagealgap will have shortened, enabling a delayed primary anastomosis
oeso-of the oesophagus in 80e90% cases During this time, the upperoesophageal pouch must be kept clear of secretions with regularsuctioning via the Replogle tube This requires skilled andintensive nursing If this is not available, then a safer but lesssatisfactory approach is to exteriorise the upper pouch in theform of a cervical oesophagostomy
If there is not enough native oesophagus to enable a delayedrepair then oesophageal substitution is required A number oftechniques are available, using stomach, colonic or small bowelinterposition
ComplicationsAnastomotic leake occurs in 5e15% of infants, usually on day
5 postoperatively Infants present with mild pyrexia, increasedwork of breathing or if they have a chest drain, saliva or milk inthe drain Most leaks will heal with conservative management,with the infant placed nil by mouth, a chest drain on freedrainage and antibiotics If the leak persists then revision surgery
is indicated
Anastomotic stricture (Figure 5)e is a common complication,especially if the anastomosis was under tension, or if there was
an anastomotic leak Anastomotic strictures usually respond to
Figure 3 Operative tracheoscopy demonstrating a tracheo-oesophageal
fistula above the carina.
Site of incision
Figure 4
Figure 2 A plain chest X-ray showing a coiled tube in the upper pouch and
gas in the stomach An associated duodenal atresia cannot be excluded
on this film and so an abdominal film is also required Note the large
thymus.
Trang 25dilatation There is higher incidence of gastro-oesophageal reflux
in patients after an oesophageal atresia repair, and the presence
of acid in the oesophageal lumen can contribute to stricture
formation Infants with a persistent stricture may require a
gastric fundoplication, after which the stricture markedly
improves
Recurrent tracheo-oesophageal fistulae this is a rare
compli-cation, most commonly occurring after an anastomotic leak which
has caused inflammation at the site of the tracheo-oesophageal
fistula repair The infant presents with recurrent chest infections
or choking or cyanosis with feeds
oesophageal atresia and is due to an inherent weakness of the
tracheal cartilages allowing the anterior and posterior tracheal
walls to move towards each other in expiration or coughing This
can lead to apnoeas when feeding or cyanotic near-death episodes
Tracheomalacia also accounts for the characteristic barking cough
that is a feature of children with repaired oesophageal atresia It
will improve with time but, if life-threatening, surgical
interven-tion is required What is often performed is an aortopexy In this
interesting operation the anterior wall of the aorta is stitched to theback of the sternum so pulling it forward The adventitia betweenthe aorta and the trachea then pulls the trachea open
Chylous leake this rare complication occurs due to a disruption
of the thoracic duct This is managed conservatively with a chestdrain on free drainage, medium-chain triglyceride (MCT) feedsand octreotide This can take up to 1 month to resolve.Oesophageal dysmotility
All infants with oesophageal atresia have a degree of abnormaloesophageal peristaltic activity This can cause dysphagia andfood bolus obstruction in the absence of a stricture Thesesymptoms tend to improve as the infant gets older
OutcomeSurvival rates for infants with oesophageal atresia haveimproved from less than 40% when repair was first undertaken
in the 1940s to 95% today There is a higher risk of death if theinfant has a birthweight below 1500 g, has major congenital heartdisease, severe associated anomalies or a long oesophageal gap.Children need follow-up to ensure that there are no ongoingproblems related to for example oesophageal dysmotility, chestinfections, gastro-oesophageal reflux, spinal anomalies and otherassociated defects The first survivors of oesophageal atresia arenow reaching their 50s and 60s Although Barrett’s oesophagusand malignant change secondary to reflux in this group of pa-tients have been described, recent population studies have not
FURTHER READING
Burge DM, Shah K, Spark P, et al Contemporary management and comes for infants born with oesophageal atresia Br J Surg 2013 March; 100: 515 e21
out-Mitchell B, Sharma R Embryology, an illustrated colour text Churchill Livingstone, 2005
Orford J, Manglick P, Cass DT, Tam PP Mechanisms for the development of esophageal atresia J Pediatr Surg 2001 Jul; 36: 985 e94
Spitz L, Kiely EM, Morecroft JA, Drake DP Oesophageal atresia: at-risk groups for the 1990s J Pediatr Surg 1994; 29: 723 e5
Stringer MD, McKenna KM, Goldstein RB, et al Prenatal diagnosis of esophageal atresia J Pediatr Surg 1995; 30: 1258 e63
Figure 5 Oesophagoscopy demonstrating an anastomotic stricture 6
months after repair of oesophageal atresia.
621 Ó 2013 Published by Elsevier Ltd All rights reserved.
Trang 26The vomiting infant: pyloric
stenosis
Brian W Davies
Abstract
Infantile hypertrophic pyloric stenosis is the commonest reason to
perform an intra-abdominal operation on a young infant It is thus an
important condition for the trainee surgeon to understand It illustrates
many important lessons in diagnosis, preoperative preparation, operative
skill and postoperative management and how to apply them to infants
and babies to achieve the excellent outcome that is expected with
mini-mal morbidity.
For these reasons, and the application of basic sciences, it is a common
topic for postgraduate examination.
For the trainee in paediatric surgery it is a key operation to learn to
perform well and is a stepping-stone to performing neonatal surgery.
Keywords Infantile hypertrophic pyloric stenosis; pyloromyotomy;
Ramstedt
Introduction
Infantile hypertrophic pyloric stenosis (IHPS) is the commonest
surgical cause of non-bilious vomiting in infancy It typically
presents 2e8 weeks after birth and is characterized by
hyper-trophy of the pyloric smooth muscle, producing a progressive
gastric outlet obstruction and a hypochloraemic metabolic
alka-losis Other common causes of non-bilious vomiting in this age
group are listed inBox 1
The first accurate description of IHPS is generally attributed to
the Danish paediatrician Harald Hirschsprung, who described
clinical and autopsy findings in 1887 The mortality rate for the
condition remained high despite attempted surgical treatments
including dilatation via gastrostomy and pyloroplasty In 1912
Conrad Ramstedt described a case of IHPS treated by transverse
pyloroplasty where the sutures cut out; unusually the patient
survived In his next patient he deliberately left the
pylo-romyotomy unsutured Although various surgical incisions to
approach the pylorus have been described since, once the
pylo-rus is reached, a Ramstedt’s pyloromyotomy is still performed
Epidemiology
In the UK the incidence of IHPS is approximately 3/1000 and
falling The incidence is much lower in AfroeCarribean and Asian
children IHPS usually presents between 2 and 8 weeks of life and
almost never beyond 3 months of age There is a 4:1 male
pre-ponderance and familial cases occur: the recurrence risk of IHPS in
the child of an affected father is 1:20 for male and 1:50 for femaleoffspring The risk of IHPS in children of an affected mother ismuch higher at 1:6 It is less frequent in breast fed babies.Aetiology
IHPS is a multifactorial sex-modified polygenic disease with athreshold model of inheritance, almost certainly with an envi-ronmental trigger
Until recently five candidate genes were implicated in thepathogenesis of IHPS The first of these is the nitric oxide synthasegene NOS1, and there is evidence of a lack of neuronal nitric oxide
in infants with IHPS The other IHPS candidate genes are alsothought to relate to smooth muscle function and regulation andone lies on the X chromosome These findings help to explain themale preponderance and the increased risk of an affected mothertransmitting the disease to her children: in order to have hadclinical IHPS she must have had a higher genetic ‘load’ of sus-ceptibility genes than a comparable affected male, and is thereforelikely to transmit the required genetic load to her children.IHPS has also been described in other genetic syndromes,such as Cornelia de Lange and Smith-Lemli-Opitz It also has ahigher incidence in children born with oesophageal atresia.Evidence for an environmental trigger comes from the factthat preterm infants develop IHPS 4e6 weeks after they are born,not at 44e46 weeks post-conceptual age The exact nature of thetrigger(s) is not known: suggestions include a prone sleepingposture and Helicobacter pylori infection
Whatever the cause, the smooth muscle hyperplasia soapparent in early infancy has been shown to regress spontane-ously later in life even if left untreated, and the pylorus resumes anormal appearance and function after several months The rea-sons for this are still not understood
In August 2013 a new genome-wide significant locus for IHPSwas found at chromosome 11q23.3 with a single-nucleotidepolymorphism (SNP) located 301 bases downstream of theapolipoprotein A-I (APOA1) gene suggesting the possibility of aninverse relationship between levels of circulating cholesterol inneonates and the IHPS risk This is an area for investigation.Diagnosis
The initial work-up of an infant with non-bilious vomiting is shown
inBox 2 The vomiting associated with IHPS is classically forceful,occurs after feeds and is described as projectile It gets progres-sively worse and the infant is hungry after vomiting ‘Coffeegrounds’ may appear in the vomitus as oesophagitis/gastritisdevelop Weight loss occurs as the disease progresses and it isimportant to review the growth charts and obtain a good feedinghistory (type of feed, amount, frequency) Urinary frequency andvolume reduces, such that parents note they are changing fewer,and less heavy, nappies Stool frequency is reduced
On clinical examination the child may show signs of dration or even shock There may be subcutaneous fat wasting,especially visible around the buttocks and cheeks Visible gastricperistalsis can be seen in up to half of cases As gastric peristalsishas a frequency of three per minute, the upper abdomen should
dehy-be observed for a few minutes The hypertrophied pyloric musclecan be felt in the upper abdomen This is described as the pyloricolive and is best felt during a test feed (Box 3)
Brian W Davies FRCS (Paed Surg) is a Consultant Paediatric Surgeon at
Nottingham University Hospitals, UK Conflict of interest: none
declared.
Trang 27Blood tests demonstrate the metabolic consequences of
repeated vomiting and dehydration as the disease progresses Hþ
and Clare lost in the vomitus, along with small amounts of Kþ
This leads to a hypochloraemic metabolic alkalosis Initially the
kidney will excrete Kþ in exchange for Hþ in an attempt to
maintain pH, but as fluid losses worsen aldosterone release is
stimulated and this promotes Naþreabsorption at the expense of
Hþ Furthermore, the relative lack of Clions in the urine leads
to HCO3 reabsorption with the Naþions, meaning that the urine
becomes paradoxically acidified It is important to appreciate that
in IHPS the potassium deficit is often pronounced Jaundice also
occurs in up to 5% of infants with IHPS, due to a deficiency of
glucuronyl transferase
Typically IHPS can be diagnosed on the basis of a good history
and clinical examination If the initial test feed is negative but a
strong clinical suspicion remains, repeated examination is often
helpful An ultrasound can be performed if there is doubt about
the diagnosis (Figure 1) Only exceptionally is there a role for an
upper gastrointestinal contrast study
Preoperative managementOnce a diagnosis of IHPS has been made the situation should beexplained to the parents and informed consent obtained It isessential to correct any metabolic disturbance before proceeding
to surgery, a process which typically takes 24e48 hours Even ifthe serum electrolytes are normal, the infant will have lost fluid
Figure 1 Ultrasound diagnosis of pyloric stenosis is based on both the appearance of the pylorus and its function Pyloric channel length and pyloric wall thickness are measured A channel length >16 mm and wall thickness is >3 mm is regarded as diagnostic The scan is a dynamic test and the presence or absence of the pylorus opening with gastric peri- stalsis and flow through the pyloric channel is also looked for The test needs to be performed by an experienced radiologist or sonographer as false positives do occur (measurement A ¼ length of pyloric channel; measurement B ¼ total width of pyloric muscle; measurement C ¼ thickness of muscle).
Diagnostic work-up of non-bilious vomiting in early
e Visible gastric peristalsis
e Palpable pylorus (test feed)
C Blood tests
Full blood count
Urea & electrolytes, including chloride and bicarbonate
Capillary blood gas
C-reactive protein/erythrocyte sedimentation rate and blood
cultures if sepsis suspected
C Urine tests e urine dipstick and culture
C Imaging e ultrasound of abdomen (if any doubt of diagnosis)
Box 2
How to perform a test feed
The best time to perform a test feed is when the infant has an empty stomach, as a full stomach can mask the palpable pyloric
‘olive’ This can be done by emptying the stomach with a gastric tube or by continuing the feed after the infant vomits The purpose of the test feed is primarily to calm the child and allow sustained palpation; increased gastric peristalsis, making the pylorus easier to palpate, is a secondary phenomenon.
naso-A towel is needed in case the infant vomits and to reassure the parents that you have listened to them The infant is held with the head on the parent’s left This allows the abdomen to be felt from the left hand side Attention is paid to the epigastric and right upper quadrant regions The liver in infants is frequently low lying and a conscious effort needs to be made to get underneath the liver edge, as the pylorus is often otherwise obscured The legs of the child can be supported and the hips flexed, which further re- laxes the abdominal wall musculature It is important to be ready and examining the abdomen prior to the feed commencing as sometimes the best opportunity to feel the hypertrophied pylorus
is in the first few swallows before the stomach fills.
Urinary tract infection
Septicaemia and meningitis
C Other (feed intolerance, gastroenteritis, inborn errors of
metabolism)
Box 1
Trang 28and electrolytes and needs intravenous fluids Feeds should be
stopped and a nasogastric tube placed A method of calculating
the chloride deficit and therefore fluid requirements is given
in Paediatric fluid and electrolyte therapy guidelines on pages
599e602 of this issue, although administration of 0.9% saline
ml/kg/day will typically correct all deficits within the 24
e48-hour timeframe mentioned above Regular monitoring of serum
electrolytes and acidebase balance on capillary blood gases is
essential as surgery is delayed until these have returned to
normal
The infant’s haemoglobin needs to be checked once If this is
normal, then the infant does not require cross-matching as blood
loss should be minimal and transfusion exceptional
Operative managementThe operation needs a team who are operating on young infants
on a regular basis Attention to keeping the infant warm duringinduction, surgery and at the end of the procedure is essential.Ramstedt’s pyloromyotomy, may be performed through aright upper quadrant, circumumbilical or laparoscopic approach(Figures 2 and 3) Medical management alone using intravenousatropine has been used successfully but requires a prolonged(median 2 weeks) stay in hospital, which compares poorly to thetypical 24e48-hour postoperative stay with surgical treatment,thus tends to be reserved for the very rare infant where generalanaesthesia is contraindicated Endoscopic balloon dilatation hasalso been described but is rarely successful
Pyloromyotomy
c b
(a) Longitudinal section of pyloric stenosi s, showing areas needing close attention to prevent complications (b) The pylorus is stabilized between thumb
and forefinger and the serosa incised longitudinally (c) The muscle is split down to the mucosa, which can be seen to bulge outwards
Incomplete pyloromyotomy most likely at gastric end Prepyloric vein of Mayo marks distal extent
Pylorus is grasped between thumb and forefinger
Mucosa bulges into pyloromyotomy
Trang 29In open surgery, the pylorus is delivered and stabilized between
thumb and forefinger This manoeuvre also invaginates the
duodenal mucosa and reduces the risk of inadvertent mucosal
perforation The pyloric serosa is then incised, the initial cut
deepened with a McDonald dissector and the muscle split to the
mucosa using an ‘up-tip-clip’ technique or a pyloric spreader The
prepyloric vein of Mayo marks the distal extent of the
pylo-romyotomy The adequacy of the muscle split can be confirmed
visually and by testing for independent movement of the two
halves Mucosal perforation can be tested for by carefully by
com-pressing the residual contents of the stomach towards the pylorus
and watching the mucosa distend Some surgeons recommend
insufflating the stomach with air, however this risks inadvertent air
embolism if the syringe is attached to an intravenous catheter
accidentally (this should not now be possible in the UK as
naso-gastric tubes and enteral syringes should not be compatible with
intravenous tubes) During the pyloromyotomy it should be
remembered that most mucosal perforations occur at the distal
duodenal end of the pylorus whilst incomplete pyloromyotomies
are commonly found at the proximal, gastric end (Figure 2)
Laparoscopic pyloromyotomy is currently controversial
Ad-vocates cite better cosmetic appearances and reduced operative
times and inpatient stay; critics cite equally good cosmetic
ap-pearances with the circumumbilical approach and increased
complications, especially incomplete pyloromyotomy requiring
re-operation, in the laparoscopic group A meta-analysis of three
randomized controlled trials comparing different results has
recently been published It showed no significant differences in
complications or outcomes
Postoperative management
The aim of postoperative care is to allow the infant to return
home promptly whilst detecting any complications early enough
to treat them with as few sequelae as possible
Observations
Following general anaesthesia an infant is monitored with an
apnoea alarm and continuous SaO2 Hourly pulse and respiratory
rate and 4-hourly temperatures should be recorded
Pain relief
Following intraoperative opiates, paracetamol and local anaesthetic
infiltration, postoperative paracetamol (oral, rectal or intravenous)
is usually sufficient Occasionally oral morphine is required
Feeding
Postoperatively a number of complex feeding regimes have been
described to minimize vomiting and accelerate discharge
Ran-domized controlled trials have shown that normal feeding (‘ad
libitum’) is equally effective Our protocol is to start feeds at
6 hours postoperatively at half the normal volume, with the
second feed also at half volume Subsequent feeds are given at
full volume Since introducing this we have reduced the mean
postoperative length of stay to 36 hours after open umbilical
pyloromyotomy
Specific early complications
approach is used)
Mucosal perforatione 1% If noted intraoperatively, then this
is repaired, feeding delayed for 24 hours and the infant observedclosely If unrepaired the infant develops peritonitis Initially thesymptoms and signs are non-specific (unsettled, raised heartrate, not interested in feeds), but by 36 hours they become un-well, pyrexial, tachycardic, tachypnoeic, distended abdomen,erythema of abdominal wall and wound, and may have guarding.Resuscitation, intravenous antibiotics, emergency surgery andhigh dependency/intensive care are required
Wound dehiscence e 0.5% is rare and due to poor surgicaltechnique Immediate surgical repair is required
Incomplete pyloromyotomy requiring redo surgerye 0.4% It
is relatively common for infants to vomit postoperatively and thevast majority of case will settle in a few days as gastric ileus settles.Persistent vomiting lasting 5 days or more warrants investigation
to exclude an inadequate pyloromyotomy Ultrasound or an uppergastrointestinal contrast study may be necessary Co-existinggastro-oesophageal reflux is common in this age group and mayrequire further treatment (thickened feeds, pharmaceutical).Discharge
Once the infant is well, has normal observations and has ated two normal feeds they can be discharged home
toler-Follow-up and long-term outcome
At discharge, the infant’s health visitor is informed The infant’sweight should be checked weekly for the first 3e4 weeks toensure appropriate weight gain; if not then clinical assessment isrequired A routine hospital out-patient appointment is notnecessary, but the family need written information of how tocontact the surgical team should they have any concerns.Following pyloromyotomy the pyloric muscle hypertrophyresolves spontaneously and long-term sequelae are extremely
FURTHER READING
Crabbe DCG Infantile hypertrophic pyloric stenosis In: Stringer MD, Oldham KT, Moriquand PDE, Howard ER, eds Paediatric surgery and urology: long-term outcomes 2nd edn Philadelphia: W B Saunders,
1998 Jia W-Q, Tian J-H, Yang K-H, et al Open versus laparoscopic pylo- romyotomy for pyloric stenosis: a meta-analysis of randomized controlled trials Eur J Pediatr Surg 2011; 21: 77 e81 Hall Nigel J, Pacilli Maurizio, Eaton Simon, et al Recovery after open versus laparoscopic pyloromyotomy for pyloric stenosis: a double-blind mul- ticentre randomised controlled trial Lancet 2009; 373: 390 e8 This is a good paper to learn critical reading skills Although it is from a world famous institution, had a research ethics committee which stopped the trial early and it was published in a high impact journal,
it still raises more questions than it answered The trial was stopped
as the infants undergoing laparoscopic pyloromyotomy had a shorter time to full feed (by 5.5 hours), but the incidence of incomplete pyloromyotomy was 3% (3 of 87) Although this is not statistically significant in their study, it compares poorly to only 0.4% in a review of 1262 pyloromyotomies by paediatric surgeons (see Crabbe above)
Trang 30Joana Lopes
Simon N Huddart
Abstract
Intussusception is the invagination of a segment of bowel into the distal
adjacent bowel Mostly it involves the distal ileum and proximal colon and
no lead point can be identified It is the most common cause of bowel
obstruction in infants and young children It typically presents in infants
between 2 months and 2 years of age with episodic severe colicky
abdominal pain, vomiting that progresses to being bilious, abdominal
distension, and bleeding per rectum which is classically described as
‘red-currant jelly’ stool If not diagnosed and treated promptly the pathology
will progress to bowel necrosis, sepsis and death.
Patients usually need resuscitation and stabilization before investigation
and definite treatment The diagnostic test of choice is an ultrasound scan of
the abdomen The first-line treatment is an air-reduction enema that will be
successful in 80% of cases Surgery with manual reduction of the
intussus-ception and possible bowel resection is reserved for cases presenting with
peritonitis, cases where a pathological lead point is identified, where
air-enema failed or where this procedure is complicated by bowel perforation.
KeywordsBowel obstruction; intussusception; redcurrant jelly
Introduction
Intussusception is defined as the invagination of a proximal segment
of intestine (intussusceptum) into the lumen of the adjacent more
distal segment of intestine (intussuscipiens) The intussusceptum
becomes the inner segment of intestine and the intussuscipiens the
outer segment of intestine in the intussusception
Intussusception leads to bowel obstruction and if untreated
necrosis of the incarcerated bowel It is the most common cause
of bowel obstruction in infants and young children
History
1674e Intussusception was first described by Paul Barbette from
Amsterdam The condition was invariably fatal
1830e The first successful surgery was performed by John
Wil-son, but the surgical mortality was more than 75%
Copenhagen best known for describing congenital megacolon
and pyloric stenosis, first described hydrostatic reduction The
diagnosis was clinical as radiographs were not available until
1895
1959e Treatment of intussusception with insufflation of airwas first described by Fiorito from Argentina
EpidemiologyThe incidence in the UK is 1.6e4 cases per 1000 live births with
a male-to-female ratio of 3:2 It typically presents in infantsbetween 2 months and 2 years of age and 50% of the casespresent between 3 months and 10 months of age and 65% of thecases before 1 year of age
There is a seasonal variation in incidence with peaks in Springand Winter corresponding to peaks in occurrence of rotavirusand adenovirus infections
Aetiology/pathophysiology
In 95% of cases the intussusception is ileo-colic, arising in thedistal ileum and passing through the ileo-caecal valve into theproximal colon In decreasing frequency of occurrence it can also
be ileo-ileal, caeco-colic, colo-colic and jejuno-jejunal
In 10% of cases a lead point (for example a polyp or mangioma) in the intestinal wall, driven by peristalsis in theadjacent intestine, drags its associated segment of intestine (theintussusceptum) into the distal bowel (the intussuscipiens)
hae-In primary or idiopathic intussusception (90% of cases) a leadpoint cannot be identified It is thought that these idiopathiccases might result from enlarged Peyer’s patches acting as a leadpoint Viral illnesses (upper tract respiratory infections andgastroenteritis) may be the cause for the hypertrophy of thelymphoid tissue Adenovirus and to a lesser extent rotavirus havebeen implicated in 50% of cases The typical presentationhappens at the age of weaning occurs raising the possibility thatimmune stimulation by newly introduced feeds may be a cause.Food allergies are also considered to be a possible cause ofprimary intussusception
The incidence of intussusception increased in the USA after theintroduction of a rotavirus vaccine in 1998 Studies showed that therisk increased 20e30-fold within 2 weeks following the first dose ofthe vaccine and three- to sevenfold within 2 weeks after the seconddose There was no increased risk after the 3rd dose or 3 weeks afterany of the doses As a result, the vaccine was withdrawn a year afterbeing licensed Two new vaccines against rotavirus were licensed inthe USA (in 2006 and 2008) These had pre-licensure trials thatspecifically evaluated the risk of intussusception and did not find it
to be increased Post-marketing surveillance is still ongoing A studythat included data on more than 800,000 doses of one of the vaccines
in the USA has not shown an increase in intussusception cases.Postoperative intussusception (1% of childhood intussuscep-tion) is another form of primary intussusception but a separateentity on its own It can happen following abdominal or thoracicsurgery, generally for malignancy, after retroperitoneal dissec-tion and after chemo- or radiotherapy It is usually ileo-ileal
It is unclear why the intussusception develops but the currentbelief is that it results from the proximal small bowel recoveringits peristalsis before the distal bowel and therefore being pushedinto the latter It may also be due to spasm or oedema of thebowel wall after surgery so acting as a lead point Or it could bedue to dysmotility
In secondary intussusception there is a pathological leadpoint Pathological lead points are more common outside the
Joana Lopes MRCS is a Specialist Registrar in Paediatric Surgery at
University Hospital of Wales, Cardiff, UK Conflicts of interest: none
declared.
Simon N Huddart MA MBBS FRCS FRCS(Paed) is a Consultant Neonatal and
Paediatric Surgeon at University Hospital of Wales, Cardiff, UK Conflicts
of interest: none declared.
Trang 31typical age range with more than 20% seen in patients over 2
years of age They are also more commonly ileo-ileal
intussus-ceptions and can recur if not excised
Possible pathological lead points are listed in Box 1 and
associated conditions are listed inBox 2
The first consequence of intussusception is bowel obstruction,
the second is compromise of the intussuscepted bowel: the
intussuscipiens distends, the intussusceptum and its mesentery
are compressed, and there will initially be lymphatic and venous
outflow obstruction, bowel wall oedema, followed by arterial
obstruction and eventually bowel necrosis
occurs However, the natural history of the condition is to
progress to sepsis and death, unless it is recognized and treated
successfully
Presentation
Over 80% of patients have episodes of colicky abdominal pain
with screaming, drawing up the legs and pallor The episodes
recur every 10e20 minutes Around 80% of patients vomit This
may be early due to the pain or late due to obstruction when it
becomes bilious Around a third of patients pass blood per
rectum with what is classically described as ‘redcurrant jelly’
stool These are dark red mucoid clots that result from
compression of the mucous glands within the intussusceptum
therefore a later sign Most patients do not pass much stool after
they have emptied their colon since they are obstructed; however
up to 20% of patients may have had diarrhoea as a prodromal
illness Only one-third of patients have the triad of colicky
abdominal pain, vomiting and bloody stools
These are generally previously fit and well children, well
nourished and in good health If early in the disease process,
between attacks the child may appear deceivingly well or asleep
As the disease progresses, the child will become progressively
lethargic in between episodes of pain, progressively more
dis-tended due to ongoing obstruction, severely dehydrated and
shocked Fever is a late sign due to bowel necrosis and sepsis
In an episode of pain, the child may be difficult to examine,there may be audible peristaltic rushes and a mass may bepalpable or even visible if the child is thin anywhere in theabdomen The classic examination finding is that of a right upperquadrant sausage-shaped mass (present in 60e80% of cases).Dance’s sign is the appearance of a flat or empty right lowerquadrant due to the mobile caecum having vacated the right iliacfossa
Rarely, the intussusceptum can be felt on rectal examination
or can be seen prolapsing through the anus This needs to bedifferentiated from a rectal prolapse as reduction of intussus-cepted bowel misdiagnosed as a rectal prolapse could be lifethreatening If a lubricated tongue blade inserted along the side
of the protruding mass can be advanced more than 2 cm into theanus the diagnosis of intussusception should be considered.Postoperative intussusception tends to have an atypicalpresentation and it should be suspected in any children withprolonged or recurrent postoperative ileus Mostly it happensfrom 10 days to within a month post-surgery It is usually ileo-
obstruction are more frequent causes for bowel obstructionafter surgery, intussusception may not be diagnosed
InvestigationsImaging
An abdominal ultrasound scan (USS) is the preferred modality ofimaging to diagnose intussusception and often it will be the onlyimaging needed Its sensitivity and specificity approaches 100%with an experienced operator It may also distinguish betweenileo-ileal intussusception and ileo-colic intussusception guidingfurther treatment
The cross-sectional view of an intussusception on USS ischaracterized by the ‘target sign’ (Figure 1) e two concentricrings of low echogenicity separated by a ring of high echogenicityrepresenting the walls of the intussusceptum and intussusci-piens Longitudinally it is characterized by the ‘pseudo-kidneysign’ (Figure 2) e superimposed layers of low and high echo-genicity representing the oedema of the bowel walls Doppler can
be used to detect blood flow within the intussusception
Pathological ‘lead points’
Associated conditions seen with intussusception
C Peutz eJeghers syndrome e hamartous polyps act as
a lead point
C Henoch eSchonlein Purpura e submucosal haematomas act as a lead point Intussusception seen in approximately 3.5% of patients with Henoch eSchonlein purpura
C Cystic fibrosis e inspissated bowel contents act as a lead point Intussusception seen in approximately 1% of cystic fibrosis patients
C Coeliac disease
C Clostridium difficile colitis Note e Intussusception has been described in premature infants and has been postulated as a possible cause for small bowel atresia in neonates.
Box 2
627 Ó 2013 Published by Elsevier Ltd All rights reserved.
Trang 32A plain abdominal X-ray is no longer the investigation of
choice but may have been taken and should be studied The
radiograph may show the features of bowel obstruction and may
give the impression of a mass (an area of paucity of bowel loops
or an opacity within a gas filled bowel loop) The target sign or
coiled spring sign is an area of concentric lucencies that
repre-sents a cross-sectional appearance of the invaginated mesentery
and bowel into the intussuscipiens The meniscus sign is a
cres-cent-shaped lucency in the colon that represents the outlining the
distal end of the intussusceptum by gas The right iliac fossa is
usually gas free However, the abdominal X-ray may be normal
A contrast enema is rarely required to make the diagnosis but
where the diagnosis is not clear, it may be diagnostic and
therapeutic
A pathological lead point should be considered in those over
2 years of age and those with recurrent intussusceptions An
ultrasound and a contrast study may help, but CT or MRI may be
necessary
Laboratory
Routine baseline blood tests need to be obtained Due to the
dehydration, blood electrolytes and renal function need to be
assessed and corrected if needed The blood loss associated with
intussusception rarely requires transfusion
Management
The management follows the advanced paediatric life support
(APLS) algorithms remembering that these children can present
in a very unwell state and need resuscitation before further
investigation or treatment
Severe abdominal distension and pulmonary aspiration ofgastric content can lead to respiratory compromise Bowelobstruction, dehydration and ill-understood associated auto-nomic changes in the vasculature can result in some childrenhaving profound circulatory compromise and requiring signifi-cant fluid resuscitation
The patient requires an appropriately sized and functionalnaso-gastric tube which is aspirated and then left on freedrainage for gastric decompression and secure intravenousaccess Sometimes supplemental oxygen and rarely endotrachealintubation are required
Fluid resuscitation may be needed to restore intravascularvolume with 0.9% normal saline or Hartmann’s given initially as
a 20 ml/kg bolus and then repeated up to two times if necessaryguided by monitoring with clinical reassessment to evaluate theresponse to treatment A blood transfusion might be needed ifhigh volumes of fluid are required and urinary catheterizationwould then be appropriate Hypothermia needs to be preventedwhilst patients are moved between different clinical areas (acci-dent and emergency/radiology suit/theatre/ward) Intravenousantibiotics (cefuroxime and metronidazole) should be started.Only stabilized patients can thereafter undergo furtherinvestigation and treatment
Radiological reduction
An air-reduction enema under fluoroscopic guidance performed
in accordance with the guidelines of the British Society ofPaediatric Radiologists is the treatment of choice Radiologicalreduction used to be performed with barium under fluoroscopicguidance for both diagnosis and treatment Water-solubleisotonic contrast has also been used as this does not carry therisks of barium peritonitis if intestinal perforation occurs Air-enemas have been shown to be as equally effective and ifperforation ensues contamination is not as extensive Thedisadvantage of air-reduction is the poorer visualization of thereduction and possible lead points and the risk of the develop-ment of a tension pneumoperitoneum
The procedure should only be undertaken once the child hasbeen resuscitated sufficiently
The absolute contraindications to radiological reduction areevidence of peritonitis or perforation and the identification of
a pathological lead point Relative contraindications are thepresence of an ileo-ileal intussusception (as they are more diffi-cult to reduce radiologically and have a higher incidence ofpathological lead points), a grossly distended abdomen andchildren above the age of 3 years as they may be too uncooper-ative for the procedure or maintain recollection of the eventswhich could be traumatic
Consent should be obtained for the procedure with discussion
of the risks of failure, perforation, tension pneumoperitoneum,cardiorespiratory collapse, need for emergency peritonealdecompression and surgery, and of course recurrence
The air-reduction enema takes place in the radiology suit withadequate resuscitation equipment and expertise (APLS-trainedstaff) available should the child deteriorate or arrest
The procedure should be performed by an experienced ologist and an experienced member of the surgical team needs to
radi-be present in order to manage the child if a tension peritoneum ensues
pneumo-Figure 1 Ultrasound scan showing ‘target sign’.
Figure 2 Ultrasound scan showing ‘pseudo-kidney sign’.
Trang 33The child should be closely monitored throughout (heart
rate and pulse oximetry as minimum monitoring
require-ments) Antibiotics and opiate analgesia (usually as
intrave-nous morphine) are given before the start of the procedure
and naloxone should be available to be administered if
needed
A catheter is inserted into the child’s rectum The child is
immobilized, with the buttocks held together (in order to
achieve a tight seal around the catheter) The catheter is
attached to a pressure monitoring device, with a cut off at 120
mmHg
Under fluoroscopic control air is insufflated into the colon to
achieve a pressure of 80e100 mmHg This pressure is held for up
to 3 minutes in order to try and reduce oedema and then the
intussusception Intermittent fluoroscopic screening allows one
to assess the progress of reduction of the intussusceptum If the
first attempt fails the child should be allowed a rest before
a further attempt is made With subsequent attempts the pressure
increases up to a maximum of 120 mmHg Up to three attempts
are made Successful reduction is demonstrated by the free flow
of air into the distal ileum If doubt remains about the success of
the reduction (the IC valve may be too oedematous to allow air to
pass into the small bowel) then a repeat ultrasound scan may be
useful
Success rates are between 75 and 80% If symptoms have
been present for more than 48 hours the success rate is lower
If reduction is successful the child is kept nil by mouth for
12 hours before fluids are allowed If the child had opiate analgesia,
monitoring needs to be continued for a period of time as respiratory
depression may develop Antibiotics can be stopped at 24 hours if
the child is well and discharge is usually possible within 48 hours
If the procedure fails but the child is stable the procedure can
be repeated 2e4 hours later If the child is not clinically well then
surgery is necessary
Of note is the fact that recurrent intussusception can be
treated following the same principles as a first episode The
success rate for air-enema is the same as for a first presentation,
even if it previously failed and surgery was needed
The most significant complication of an air-reduction enema
is perforation of the bowel If this occurs the high pressure gas
within the colon escapes and causes a tension
pneumo-peritoneum, which may compress the inferior vena cava and lead
to cardiovascular collapse Immediate treatment is necessary
with insertion of a large-bore cannula into the abdomen to
release the pressure Definitive management is by laparotomy
The perforation can happen either under the form if a small
necrotic patch of bowel or a long linear tear along the
anti-mesenteric border of the bowel
Surgery
Surgery is performed if there is a contraindication to radiological
reduction or, if this was unsuccessful, if radiological reduction
created a perforation or the parents have refused to give consent
to an air-reduction enema
A transverse muscle-cutting incision is made on the
right-hand side of the abdomen, usually above the level of the
umbi-licus The intussusception is delivered (Figure 3) (it is
occa-sionally necessary to mobilize the colon to achieve this)
Moderate serous ascites may be found due to the obstruction
Once the edge of the intussusceptum is found this is gentlymanipulated back upstream Mild pressure can decrease theoedema and help with the manoeuvre Pulling the intussuscep-tum should not be attempted, as it is likely to cause tearing orperforation If the intussusception is reduced the bowel must beassessed for viability and to examine for a lead point It isimportant to realize that the first part of the intestine to invagi-nate and the last part to reduce may be particularly thickenedand indented This is commonly seen and is not a pathologicallead point and does not need resection
Inability to reduce the intussusception, concerns over theviability of the bowel or identification of a pathological leadpoint require a resection (needed in approximately one-third toone-half of cases) this might be a simple resection or a limitedright hemicolectomy with an end-to-end anastomosis or rarely
a diverting stoma depending on the condition of the bowel andchild
An incidental appendicectomy may be performed especially if
a lower incision has been selected
Postoperatively the child should have a naso-gastric tube inplace, receive adequate analgesia, fluids and antibiotics and bemonitored closely Normally it is possible to start oral fluids 12e
24 hours after once any ileus has settled Patients should only bedischarged when eating and stooling normally
Laparoscopy started being used for diagnostic purposes only.However its role in managing intussusception is evolving withsome surgeons are using it to attempt reduction only and ifunsuccessful they proceed to a laparoscopic-assisted procedure(by exteriorization of the bowel through a periumbilical incision)
or converting to open, but some centres are using laparoscopyeven if bowel resection is needed
The majority of surgeons will be using a three-port technique(one infraumbilical port, two ports on the left-hand side of theabdomen) An atraumatic bowel clamp is used to grasp theintussusceptum and an intestinal grasping forceps is used to holdthe caecum The caecum is then pushed away while pressure isapplied distal to the intussuscipiens
The main difference from the open technique is that traction
on the proximal bowel is usually required
Figure 3 Intraoperative picture of an intussusception that has been delivered.
629 Ó 2013 Published by Elsevier Ltd All rights reserved.
Trang 34If diagnosed and treated promptly, the current prognosis of
intussusception is excellent, with patients having no long-term
complications
There is a 1% risk of perforation with air-enema reduction,
more likely if the history is long (>48 hours) Post-perforation
the main risk is respiratory compromise due to tension
pneu-moperitoneum that needs to be decompressed immediately, any
peritoneal contamination tends to be minimal
The recurrence rate is less than 5% In 30% of cases it occurs
within 24 hours, in 70% of cases within 6 months Recurrence is
less likely after surgical treatment
Intussusception has a mortality (<1%) with deaths associated
with a delay in diagnosis, inadequate fluid resuscitation,
inade-quate antibiotic cover and failure to recognize recurrent or
residual intussusception following reduction
FutureSlow hydrostatic reduction with saline enema under ultrasoundguidance has been reported in China with 95.5% of 5218patients having successful reduction and a perforation rate of0.17% with no mortality This method has the advantage of notrequiring radiation and might be an alternative to currentpractice The likely increased reduction rate may be due to thetime over which reduction takes place Oedema may be morelikely to resolve with gentle pressure applied over a longer timethan with the three short, sharp, high-pressure periods currently
FURTHER READING
Grosfeld JL Pediatric surgery 6th edn Philadelphia: Mosby Elsevier, 2006.
Trang 35Anorectal anomalies and
Anorectal malformations are congenital anomalies caused by a failure of
the hindgut to open into an adequate position on the perineum They are
often associated with congenital anomalies in other systems A thorough
understanding of the anatomical aberration will allow surgical planning
and correction of the defect This article outlines the principle
consider-ations in diagnosis, early and definitive management of these defects.
Hirschsprung disease is a congenital anomaly caused by a failure of
development of the enteric nervous system and consequent absence of
ganglia Marked spasticity of the bowel and functional bowel obstruction
ensue This article discusses recognition, diagnosis, initial and definitive
management.
In both conditions sequelae include life-long incontinence
Optimiza-tion of long-term outcomes is therefore important and meticulous surgical
management in early life should be coupled with careful follow-up.
Keywords Aganglionosis; anorectal malformation; Duhamel procedure;
imperforate anus; PSARP; Soave procedure; Swenson procedure;
transi-tion zone; VACTERL associatransi-tion
Introduction
Anorectal malformations (ARM) and Hirschsprung disease (HD)
together constitute a significant part of paediatric colorectal
surgical practice Both are congenital anomalies caused by
anatomical (in the case of ARM) or physiological (in the case of
HD) aberrations that require meticulous surgical management
The sequelae of congenital anomalies are likely to affect a
neonatal patient for decades onwards and careful attention to
follow-up is required if long-term functional outcomes are to be
optimized
Anorectal malformations
An ARM is a congenital abnormality in which the terminalportion of the hindgut fails to open into the correct position onthe perineum or does so but with an inadequate calibre.The incidence varies between areas and is approximately
Spectrum of diseaseARMs fall into a spectrum in both males and females
Males: the spectrum of abnormalities and the relationship tween the hindgut and the urethra are illustrated inFigure 1.The most minor defect in a male is a perineal fistula Here, thehindgut opens onto the perineum but, since it is anterior to thenormal position, it is incompletely surrounded by sphincter Nextare malformations in which the hindgut terminates as a fistulainto the urethra This may be a recto-bulbar urethral fistula or arecto-prostatic fistula At the most severe end of the spectrum aredefects in which the hindgut ends in a fistula into the bladderneck (recto-bladder neck fistulae) or bladder (recto-vesical)
be-Of clinical importance is the anatomical relationship betweenthe hindgut and the urinary tract; for the recto-perineal fistulae,there is always some distance between the two structures Forthe other defects this is not the case For the recto-bulbar urethraand the recto-prostatic fistulae, not only do the hindgut andurethra lie in close proximity, they are almost parallel In thesepatients, the walls of the hindgut and the urethra effectivelyshare a ‘common wall’ which may extend for some distancenecessitating particular care in dissection The trajectory of thehindgut relative to the urinary tract for the recto-bladder neckfistulae tends to be more perpendicular and a common wall isless of an issue
In addition to this spectrum in males, there are some specialsituations worthy of mention:
‘ARM with no fistula’ This occurs when the hindgut isblind ended and is seen most frequently in Down syn-drome Although there is no fistula into the urethra, there
is often a common wall, as per recto-bulbar urethraldefects
Stenosis Here the hindgut opens onto the perineumthrough the sphincters but is stenotic either at skin level(anal stenosis) or higher up at the level of the dentate(rectal stenosis)
Bucket handle defect Here, the hindgut does not enter theurinary tract but lies just under the skin surface Theoverlying skin has a typical appearance in which themidline raphe becomes prominent (hence the namebucket-handle) This is similar to a perineal fistula.Females: the spectrum of abnormalities in females is illustrated
inFigure 2 At the minor end is the perineal fistula In keepingwith its male counterpart, the hindgut opens onto the perineumbut is incompletely surrounded by sphincter, and may also bestenotic
Since the introitus and vagina, rather than the urethra, lieanterior to the hindgut, the next most severe defects are therecto-posterior forchette fistula (in which the hindgut enters atthe posterior corner of the introitus) and the recto-vestibular
Jonathan Sutcliffe FRCS (Paed Surg) MD is a Consultant Paediatric Surgeon
at the Leeds General Infirmary, UK Conflicts of interest: none.
Ian Sugarman FRCS (Paed Surg) is a Consultant Paediatric Surgeon at the
Leeds General Infirmary, UK Conflicts of interest: none.
Marc Levitt MD FACS is a Consultant Paediatric Surgeon, Director of the
Colorectal Center for Children and Professor of Surgery, Cincinnati
Children’s Hospital and the University of Cincinnati, Cincinnati, OH,
USA Conflicts of interest: none.
Trang 36fistulae (in which the hindgut enters introitus itself and so can be
seen at a point distal to the hymen) As with fistulae that enter
the urethra in males, there is often a common wall (here between
hindgut and the vagina) that makes delicate dissection essential
The most severe defect in females is a cloaca Here, not only
does the hindgut open directly into the vagina, but the urethral
orifice is also abnormal, lying high on the anterior vaginal wall
(‘female hypospadias’) In cloacae therefore, urinary, genital and
intestinal structures all drain into a common channel The point
at which these two structures open into the vagina may be
relatively close to the skin (producing a short common channel)
or may be much more proximal (producing a long common
channel) The length of the common channel correlates with
prognosis
Clinical presentation
Whilst ARMs are almost always clinically obvious when
inspecting the perineum at neonatal examination, the frequency
with which they are missed during the neonatal assessment is
surprisingly high In part this is because some abnormalities (e.g
recto-perineal fistulae or stenoses) have the potential to transmit
stool onto the newborn perineal skin If an unsuspecting clinician
fails to clean away this meconium then the defect will remain
undiagnosed A less common scenario occurs when the
abnor-mality lies at the level of the dentate line (for example rectal
stenosis) but the external structures look normal Delay in
diagnosis is however seen even at the most severe end of the
spectrum and one recent report from the UK demonstrated that
up to 50% of newborns with ARM were missed at the neonatal
examination.1
AssessmentOnce an abnormality has been identified, the primary objectivesare to:
determine if a stoma is needed before definitive repair ornot
look for associated abnormalities
Stoma or not? ARMs in which the position of the hindgut isclinically obvious and clearly separated from the urinary tract aredeemed ‘low’ and considered amenable to definitive repair in theneonatal period This effectively means recto-perineal fistulae
In contrast, defects at the severe end of the spectrum have aclose anatomical relationship between the hindgut and the uri-nary tract Furthermore, the distance of the hindgut from theperineal skin may be significant (indeed the hindgut may be sohigh that it cannot be reached safely from a perineal incision).Surgical exploration without a clear understanding of anatomy
in the neonatal period is hazardous This group of defects isdeemed to be ‘high’ and by definition requires a temporarystoma
Categorization of abnormalities into low and high can beperformed by clinical assessment alone in almost all patients If afistula is seen to enter the perineum, or a bucket handle isobserved, one can be sufficiently confident of the position of thehindgut to consider definitive repair if the baby is otherwise well
If meconium is seen in the urinary stream (this typically takes
24 hours or so) then a fistula is proven and a stoma required.Other clinical signs indicating a high abnormality are poorlyformed buttocks and perineal musculature, or a foreshortenedsacrum on plain X-ray
Figure 1 Recto-perineal, recto-bulbar urethral, and recto-bladder neck fistulae (From Pena A, Surgical Management of Anorectal Malformations, 1989 With kind permission of Springer Science & Business Media.)
Figure 2 Recto-perineal, recto-vestibular and cloacal defects (From Pena A, Surgical Management of Anorectal Malformations, 1989 With kind permission
of Springer Science & Business Media.)
Trang 37In only a few neonates does sufficient doubt exist as to the
need for a stoma or not that radiology is needed The most useful
investigation is a prone lateral shoot through with a radio opaque
pellet applied carefully to the point where the anus might have
been expected A catch for the unwary is the need for sufficient
pressure upstream to a fistula for it to be delineated and the
examination is best performed at around 24 hours of age
In some centres, ultrasound has been used although this
re-quires particular experience on the part of the radiologist; too
much pressure on the perineum will compress tissues giving an
erroneous appearance of a low defect Other investigations such
as MRI are not recommended as the lack of pressure above a
fistula is likely to produce misleading but persuasive results
When required, formation of a stoma for ARM will allow the
child to decompress (and then feed) and also allows detailed
investigation of the anatomy of the ARM to inform surgical
plan-ning using a distal loopogram Here, water-soluble contrast is
instilled into the terminal portion of the hindgut from above via a
mucous fistula If sufficient pressure is applied to the contrast, it
will enter the urinary tract, demonstrating a fistula if present
Although cloacae are at the most severe end of the spectrum
they may be missed, or mislabelled as a recto-vaginal fistula In
reality, recto-vaginal fistulae are rare and are often cloacae in
which the urethral abnormality has not been recognised Since
surgical correction of cloacae often entails mobilization of the
urethra at the same time as the hindgut, and all cloacae require a
stoma, correct diagnosis is of practical importance
Associated anomalies: a well-recognized association is the
VACTERL association which is comprised of Vertebral
Ano-rectal, Cardiac, Tracheo-Oesophageal, Renal tract and Limb
ab-normalities The likelihood of these abnormalities co-existing
increases with the severity of ARM but even minor ARMs can be
affected
All babies should have spinal and sacral plain films, spinal
ultrasound (to look for evidence of bony anomalies or a tethered
cord), a full cardiology assessment, renal tract ultrasound and
limb examination The degree of sacral foreshortening can help
infer prognosis and is therefore an important clinical feature to
guide discussion with families
The presence of one congenital anomaly increases the
likeli-hood of others and a careful neonatal examination is needed
Cloacae, and to a lesser extent, any other ARM in a female may
be associated with gynaecological abnormalities such as bifid
uterus, vaginal septum or even vaginal agenesis.2 In cloacae,
collections of fluid in the uterus (hydrometrocolpos) are
some-times seen and may be so marked that ureteric compression and
renal impairment occurs Drainage of this fluid with a pigtail
catheter placed through the abdominal wall will usually address
this emergency
Other less common associated abnormalities include the
as-sociation of rectal or anal stenoses with an abnormal sacrum and
the development of a presacral mass (Currarino triad) For this
reason, MRI is recommended in these defects
Management
Neonatal placement of stoma: for those abnormalities deemed
to be high, a stoma is formed The placement of the stoma at the
junction of the descending colon and the sigmoid colon allows
enough proximity for contrast to be injected with sufficientpressure to demonstrates a urinary fistula but not so low that itimpedes surgical repair (Figure 3) This is the divided descendingcolostomy
Definitive surgical management: once the neonate has beenfully assessed clinically, had a stoma formed (if needed) andundergone a distal loopogram to delineate anatomy, definitivesurgery is undertaken The posterior sagittal anorectoplasty(PSARP), described by Pena in 1982,3involves a midline incisionthough the perineum Pelvic muscles and subtending innervationare already paired A midline incision minimizes further iatro-genic injury to these structures whilst at the same time allowingexcellent exposure
By using muscle stimulation throughout the dissection, thepaired musculature can be readily identified on both sides Aswell as seeing levator ani, sphincteric muscle is also seen to runparallel to skin at a superficial level (probably representingexternal sphincter) and then perpendicular to the skin (probablyrepresenting an extension up to the levator)
PSARP allows safe exposure of the hindgut and its meticulousdissection from the urethra where necessary, mobilization of anadequate length of bowel and precise placement of the ‘neoanus’within the sphincteric tissue with accurate re-apposition of pelvicmusculature (Figure 4)
For the most severe defects, the distal loopogram strates that the hindgut lies so high within the pelvis that itcannot safely be reached with a PSARP approach alone For thesepatients, the PSARP can be combined with an abdominalapproach Although an open approach through a Pfannenstielincision may be employed, a laparoscopic approach provides an
demon-Figure 3 Divided descending colostomy (From Pena A, Surgical ment of Anorectal Malformations, 1989 With kind permission of Springer Science & Business Media.)
Trang 38excellent view into the pelvis and facilitates safe division of these
high fistulae Defects likely to benefit from this approach are
recto-bladder neck and high recto-prostatic, not only because the
fistulae are easily accessible from above but also because as
described above, the length of the common wall is short Such a
combined approach means that the PSARP incision need only be
long enough to allow an entrance to the peritoneum since a full
exploration is not required Precise placement of the neorectum
and neoanus within the sphincteric mechanism, and tacking of
the posterior wall to the sphincters, can then be performed
The laparoscopic approach has also been combined with a
pull through using a perineal laparoscopic port but this arguably
does not allow sufficiently accurate placement of the bowel
within the musculature, is often associated with prolapse and
risks injury to the urethra and distal ureters Pull though using a
port is no longer recommended by the current authors
One further consideration of laparoscopic ligation of the
fis-tula is the importance of not leaving a significant stump of
in-testinal tissue on the urinary tract Doing so predisposes to stone
formation, potential sepsis and, given the risks of long-term
exposure of colonic mucosa to urine, even malignancy.4
In most centres a programme of anal dilatations commences at
approximately 2 weeks postoperatively This reduces the
likeli-hood of cicatrization the circular wound at the point where the
neoanus is anastomosed to the skin Dilatations are undertaken by
the parents with support from nurse specialists and continued
until the faecal stream is rediverted to the perineum following
stoma closure This usually takes place after 6 weeks or so
Long-term outcome
Long-term outcomes now exist for this condition which
demon-strate that:
Low abnormalities tend to be predisposed to constipation
although almost all are continent of both faeces and
urine
Approximately 60e80% of patients with a high mality have impaired continence Management of thisscenario must be proactive If the child is to avoid theserious psychological consequences of soiling, symptomsshould be controlled before the child reaches school age Insome, control can be achieved by artificially thickening thestool with medication and/or dietary manipulation Inothers, rectal irrigations can be employed to empty thebowel fully once every 24 hours or some form of antegradecontinence enema procedure is performed such as aMalone procedure
abnor- Cloacae are worthy of particular mention; in addition to arelatively high risk of impaired continence, the degree andfrequency of associated urinary tract and gynaecologicalabnormalities is such that a multidisciplinary approach andinvolvement of experts in both urological and gynaeco-logical aspects is essential for good outcome The relativeinfrequency with which these abnormalities appear meansthat such a team does not always exist in every centre
The long-term sequelae do not tend to improve ously with time In all patients, early detection andcorrection of symptoms is crucial
spontane-Hirschsprung diseaseHirschsprung disease (HD) is a congenital motility disorderaffecting the intestine It is characterized by an absence of gan-glion cells (aganglionosis) The role of ganglion cells is as a relaypoint for the enteric nervous system (ENS) and an absence leads
to spasticity of the bowel and functional obstruction The dence is about 1:5000 live births
inci-Spectrum of diseaseThe distribution of HD is such that the most distal part of therectum is always affected The length of the segment varies andalthough the proximal extent of aganglionosis most often lies
Figure 4 PSARP allows safe identification of the hindgut through a midline dissection Muscle fibres of sphincter complex are clearly seen Stay sutures have been placed on the hindgut wall to allow it to be safely opened, fistula identified and divided The hindgut can then be dissected away from the urinary tract (From Pena A, Surgical Management of Anorectal Malformations, 1989 With kind permission of Springer Science & Business Media.)
Trang 39within the rectosigmoid (classic segment), it may involve the
whole colon (total colonic aganglionosis) and even small bowel
Above the aganglionic zone lies the transition zone (TZ) in
which ganglion cells are present but other ENS abnormalities are
still seen Above the TZ lies the ganglionic bowel Because of the
downstream functional obstruction, the ganglionic bowel is often
distended just above the TZ (Figure 5)
The eyes only see what the mind is prepared to comprehend
-Henri BergsonWhen Harald Hirschsprung first recognized this disease as an
entity he believed the obviously distended segment to be the
cause of symptoms Since this is the ganglionic segment, no
histological abnormality was found within it Although spastic,
the aganglionic segment looks almost normal in comparison to
the distended bowel above The aganglionic segment was not
recognized as the true cause of the problem for a further 60 years
This vignette underlines the need to think laterally when trying
to understand as yet unexplained disease processes
Clinical presentation
A majority of patients with HD present in the neonatal period
with a distal obstruction evidenced by abdominal distention,
bilious (i.e green) vomiting and delayed passage of first stool (or
meconium) Since more than 98% of term neonates will have
passed meconium within 24 hours, a delay beyond this in
conjunction in association with other clinical features is
consid-ered significant The risk of transmission to offspring is 1e33%
and varies with length of segment and gender of the index case.5
Since there is a degree of hereditability a positive family history is
sometimes seen and must always be sought
Other congenital abnormalities must be excluded on clinical
assessment, as there are a number of syndromes associated with
HD, most notably Down syndrome A small group of genetic
defects have now also been described including the RET
muta-tion Identification of a RET mutation raises the possibility of
multiple endocrine neoplasia type 2b (MEN 2b) and therefore
medullary thyroid cancer
HD may also be associated with enterocolitis characterized by
systemic sepsis, distention and offensive loose stool Although
some clinical features of enterocolitis are shared with infective
gastroenteritis, the severity and rapidity of progress are such that
this can be a lethal condition and must be considered as a
diagnosis in any child known to have HD or indeed in a newborn
presenting with these features
Once other differential diagnosis of a distal obstruction have
been excluded such as neonatal sepsis, missed ARM (see above),
intestinal atresia and meconium ileus, rectal washouts are
commenced using warm saline delivered though a soft rectal tube
and delivered by experienced staff As long as the volume instilled
on each washout (perhaps 50 ml) equates reasonably closely to
that returned there is no upper limit on the total volume of volume
of washouts to be used This technique produces adequate
decompression in most patients and has radically changed the
management of HD by reducing the need for a stoma
If severe enterocolitis is present, the segment is too long to
allow washouts, or in the relatively rare event that washouts fail
in classic segment disease, a stoma should be considered
Although in the recent past, stoma formation was considered thenorm following HD diagnosis, stomas are associated withfrequent complications and additional surgery They are to beavoided in HD where possible
A less common presentation is the older child with stipation Since the number of older children with constipationwithout an obvious cause is high, indications as to which of thesepatients require biopsy have been produced; patients with a his-tory of delayed passage of meconium, constipation from the firstfew days of life, a positive family history, previous enterocoliticsymptoms, failure to thrive and an explosive decompressionshould be considered as good indications in a constipated child.6Diagnosis and investigation
con-The gold standard is rectal biopsy For neonates, this minorprocedure can be performed on the ward, but with antibioticcover and consent Whilst an absence of ganglion cells is diag-nostic, the presence of thickened nerve trunks, staining brownwith acetylcholinesterase (AchE) is considered to be a furtherfeature supporting the diagnosis (Figure 5)
Anorectal manometry is said by some to be of value in thediagnosis but is insufficiently accurate and does not obviate theneed for biopsy A contrast enema is performed in the neonatalphase in some but not all centres Whilst it too does not reducethe need for biopsy, it can give information about the position ofthe TZ When the TZ is in the classic position i.e recto sigmoid,this investigation may help surgical planning If the whole of thecolon is affected, contrast enemas are notoriously misleading andmust be interpreted in the context of the clinical setting Onefurther benefit of the contrast enema is to inform the manage-ment of the rectal washouts by providing an estimate of thevolume needed to reach the distended bowel above the TZ.Definitive management
Following a period of washouts to reduce proximal distention,definitive surgery is performed This is typically undertaken after
4e8 weeks although in some centres this now takes place in theneonatal period Broadly there are three main operations incurrent use (Figure 6) In all procedures, the principles are toremove aganglionic bowel, to accurately identify and preservethe anal canal and to pull though the ganglionic bowel to a point
at or just above the dentate line
Swenson procedure This was the first described procedureand involves the mobilization of the aganglionic colonfrom above the dentate line Dissection continues proxi-mally in a plane outside the serosa until distended bowel isreached Full-thickness biopsies are then sent to a waitingpathologist for frozen section If histological appearancesdemonstrate that a point above the TZ has been reached,this section of bowel is pulled through and anastomosed tothe dentate line and the abnormal bowel downstream isresected
This has become increasingly popular again in recentyears, especially in the USA, as previous concerns aboutpotential iatrogenic injury to the sacral outflow have beenaddressed with strict maintenance of a plane of dissectionimmediately on the serosa of the rectum This procedure isnow performed transanally with or without laparoscopicassistance (see below)
Trang 40Ganglion cells
submucosa
mucosa
muscularis propria