However, recent reports show that symptoms alone do not differentiate between the subgroups of functional constipation.6, 15, 16 In fact, up to 62% of patients with pelvic floor dysfunct
Trang 1improved outcomes in colon and rectal surgery
stenosis or hernia Experienced plastic surgeons can carefully use
liposuction techniques to remove subcutaneous fat around the
stoma Obviously, care must be taken to not injure the stoma
during the procedure and to leave a flat smooth peristomal skin
surface for the ostomy faceplate Once the fatty tissue is removed,
it will not be redeposited despite additional weight gain
ostomy Reversal
Reversal of temporary stomas should be undertaken as soon as
physiologically feasible to reestablish gastrointestinal continuity
and for psychological improvement This of course implies that
the purposes of the stoma placement has been met and the patient
is capable and a candidate for another operative procedure There
are two main operative approaches to ostomy reversal, local or via
a laparotomy While both approaches are associated with
inadver-tent enterotomies, bleeding, wound infections, and anastomotic
complications, the biggest advantages of the laparotomy approach
is improved exposure and the ability to reexplore the abdomen
Certainly, the type of ostomy is important to consider when
plan-ning the operative approach as loop ileostomies are technically
the least challenging to reverse and often amenable to local
rever-sal Although a local approach is preferred, patients with a prior
Hartmann’s procedure or those in which the distal remnant is not
available via a local approach are obviously forced to undergo a
repeat laparotomy Surprisingly, there is a paucity of recent data
that highlights the potential perils of this seemingly benign
opera-tion The most recent study, published in 2005, was a retrospective
review of 533 patients undergoing stoma closure at the University
Hospital of Vienna.(70) The majority of the patients (51%)
under-went reversal of a colostomy, 44% had closure of an ileostomy, and
5% had combined reversals of both a colostomy and an ileostomy
All patients underwent a laparotomy using the intraperitoneal
approach Their 30-day mortality was 3% (15 patients) with rates
similar for either ileostomy or colostomy reversal Causes of death
were multisystem organ failure after nonsurgical complications in
nine patients, and anastomotic leakage, missed small bowel injury,
and cecal perforation in the remaining six patients Overall
com-plications were 20%, with anastomotic leakage (5%), ileus (4%),
postoperative bleeding (2%), and wound infection (2%) When
analyzing patient related factors between survivor and
nonsur-vivors, only advanced patient age was found to be statistically
significant This study, which highlights the potential morbidity
of stoma reversal, also emphasizes the importance of meticulous surgical technique required in these challenging patients with reoperative abdomens
Our approach to ostomy reversal begins with a thorough pre-operative evaluation which includes interrogation of the distal colon with either a barium enema and/or endoscopy The primary reason for which sentinel procedure was performed is important
to consider since it may reveal if the purposes of the ostomy has been met and potentially alter the decision on reversal An obvi-ous but sometimes overlooked step should also be the evaluation
of the patient’s sphincter tone and ability to control fecal stream once continuity has been restored This may require not only clinical evaluation, but formal documentation through anorectal physiology testing including manometry Baseline poor sphincter tone or incontinence should be considered a contraindication for ostomy reversal in all but the rarest of cases Finally, additional patient factors which can be altered, such as nutritional status, steroid use, and tobacco abuse, should be optimized before sur-gery When planning the operative approach for end colostomy reversals, additional factors to consider before embarking on the operation should include the expected amount of adhesive disease likely to be encountered or previously encountered (i.e., review prior operative notes), whether there is a history of prior abdomi-nal or pelvic radiation, concomitant pathology such as the pres-ence of incisional hernias, and the type of ostomy For instance, patients with multiple prior surgeries and a history of radiation will most likely benefit from a laparotomy approach that includes preoperative ureteral stent placement, while those patients with loop ostomies without any other comorbidities can be managed with a local approach Whether a stapled or hand-sewn anasto-mosis is performed is up to the surgeon’s discretion Key technical points in each method, however, is to ensure adequate mobiliza-tion and visualizamobiliza-tion of the distal colonic or rectal stump with resection of both the exteriorized bowel or end stump back to normal healthy bowel before the anastomosis Finally, delayed primary closure is performed for the area in which the stoma was placed and drains are not routinely placed
COnClusiOn
Beyond bringing a loop of bowel to the skin surface, there are a wide variety of issues that a surgeon needs to consider when creat-ing a stoma Havcreat-ing a thorough understandcreat-ing of the indications
Figure 33.11 Mercedes or triangular closure A Stoma site with fascia closed, B Initial approximation of skin and subcutaneous fat, C Completed closure with small
area in center left open for drainage and secondary healing.
Trang 2for stoma placement, the technical details for the various ostomies,
and the physical and psychological impact of living with an ostomy
will aid the surgeon in caring for these unique patients Finally,
understanding the potential complications from ostomy
place-ment and having the knowledge to correctly deal with them is an
essential tool for all providers and emphasizes the importance of a
multidisciplinary team of specialists
REfEREnCES
1 Sutherland AM, Orbach CE Psychological impact of cancer
and cancer surgery II Depressive reactions associated with
surgery for cancer Cancer 1953; 6: 958–62
2 Follick MJ, Smith TW, Turk DC Psychosocial adjustment
following ostomy Health Psychol 1984; 3: 505–17
3 Gerharz EW, Weingartner K, Dopatka T et al Quality of life
after cystectomy and urinary diversion: results of a
retro-spective interdisciplinary study J Urol 1997; 158: 778–85
4 Nilsson LO, Kock NG, Kylberg F et al Sexual adjustment in
ileostomy patients before and after conversion to continent
ileostomy Dis Colon Rectum 1981; 24: 287–90
5 Nugent KP, Daniels P, Stewart B et al Quality of life in stoma
patients Dis Colon Rectum 1999; 42: 1569–74
6 Walsh BA, Grunert BK, Telford GL et al Multidisciplinary
management of altered body image in the patient with an
ostomy J Wound Ostomy Continence Nurs 1995; 22: 227–36
7 Sharma A, Sharp DM, Walker LG et al Predictors of early
post-operative quality of life after elective resection for colorectal
cancer Ann Surg Oncol 2007; 14: 3435–42
8 Gervaz P, Bucher P, Konrad B et al A prospective
longitu-dinal evaluation of quality of life after abdominoperineal
resection J Surg Oncol 2008; 97(1): 14–9
9 Krouse RS, Grant M, Wendel CS et al A mixed-methods
evaluation of health-related quality of life for male veterans
with and without intestinal stomas Dis Colon Rectum 2007;
50(12): 2054–66
10 Cornish JA, Tilney HS, Heriot AG et al A meta-analysis of
quality of life for abdominoperineal excision of rectum
ver-sus anterior resection for rectal cancer Ann Surg Oncol 2007;
14: 2056–68
11 Ma N, Harvey J, Stewart J et al The effect of age on the
qual-ity of life of patients living with stomas: a pilot study ANZ
J Surg 2007; 77: 883–5
12 Norton C, Burch J, Kamm MA Patients’ views of a colostomy
for fecal incontinence Dis Colon Rectum 2005; 48: 1062–9
13 Kasparek MS, Glatzle J, Temeltcheva T et al Long-term quality
of life in patients with Crohn’s disease and perianal fistulas:
influence of fecal diversion Dis Colon Rectum 2007; 50(12):
2067–74
14 ASCRS and WOCN Joint Position Statement on the Value of
Preoperative Stoma Marking for Patients Undergoing Fecal
Ostomy Surgery J Wound Ostomy Continence Nurs 2007;
34(6): 627–8
15 Carne PW, Robertson GM, Frizelle FA Parastomal hernia
Br J Surg 2003; 90: 784–93
16 Bass EM, Del PA, Tan A et al Does preoperative stoma marking
and education by the enterostomal therapist affect outcome?
Dis Colon Rectum 1997; 40: 440–2
17 Roe AM, Prabhu S, Ali A et al Reversal of Hartmann’s pro-cedure: timing and operative technique Br J Surg 1991; 78: 1167–70
18 Keck JO, Collopy BT, Ryan PJ et al Reversal of Hartmann’s procedure: effect of timing and technique on ease and safety Dis Colon Rectum 1994; 37: 243–8
19 Brooke BN The management of an ileostomy, including its complications Lancet 1952; 2: 102–4
20 Kock NG, Darle N, Hulten L et al Ileostomy Curr Probl Surg 1977; 14: 1–52
21 Pemberton JH, Phillips SF, Ready RR et al Quality of life after Brooke ileostomy and ileal pouch-anal anastomosis Comparison of performance status Ann Surg 1989; 209: 620–6
22 Das P, Smith JJ, Tekkis PP et al Quality of life after indefi-nite diversion/pouch excision in ileal pouch failure patients Colorectal Dis 2007; 9: 718–24
23 Nessar G, Fazio VW, Tekkis P et al Long-term outcome and quality of life after continent ileostomy Dis Colon Rectum 2006; 49: 336–44
24 Kohler LW, Pemberton JH, Zinsmeister AR et al Quality of life after proctocolectomy A comparison of Brooke ileo-stomy, Kock pouch, and ileal pouch-anal anastomosis Gastroenterology 1991; 101: 679–84
25 Berndtsson IE, Lindholm E, Oresland T et al Health-related qual-ity of life and pouch function in continent ileostomy patients: a 30-year perspective Dis Colon Rectum 2004; 47: 2131–7
26 Litle VR, Barbour S, Schrock TR et al The continent ileostomy: long-term durability and patient satisfaction J Gastrointest Surg 1999; 3: 625–32
27 Castillo E, Thomassie LM, Whitlow CB et al Continent ileo-stomy: current experience Dis Colon Rectum 2005; 48(6): 1263–8
28 Wong NY, Eu KW A defunctioning ileostomy does not pre-vent clinical anastomotic leak after a low anterior resection: a prospective, comparative study Dis Colon Rectum 2005; 48: 2076–9
29 Matthiessen P, Hallbook O, Rutegard J et al Defunctioning stoma reduces symptomatic anastomotic leakage after low anterior resection of the rectum for cancer: a randomized multicenter trial Ann Surg 2007; 246: 207–14
30 Williams NS, Nasmyth DG, Jones D et al De-functioning stomas: a prospective controlled trial comparing loop ileostomy with loop transverse colostomy Br J Surg 1986; 73: 566–70
31 Edwards DP, Leppington-Clarke A, Sexton R et al Stoma-related complications are more frequent after transverse colostomy than loop ileostomy: a prospective randomized clinical trial Br J Surg 2001; 88: 360–3
32 Gooszen AW, Geelkerken RH, Hermans J et al Quality of life with a temporary stoma: ileostomy vs colostomy Dis Colon Rectum 2000; 43: 650–5
33 Leong AP, Londono-Schimmer EE, Phillips RK Life-table analysis of stomal complications following ileostomy Br J Surg 1994; 81: 727–9
34 Londono-Schimmer EE, Leong AP, Phillips RK Life table analysis of stomal complications following colostomy Dis Colon Rectum 1994; 37: 916–20
Trang 3improved outcomes in colon and rectal surgery
35 Porter JA, Salvati EP, Rubin RJ et al Complications of
colos-tomies Dis Colon Rectum 1989; 32: 299–303
36 Park JJ, Del PA, Orsay CP et al Stoma complications: the
Cook County Hospital experience Dis Colon Rectum 1999;
42: 1575–80
37 Cottam J, Richards K, Hasted A et al Results of a nationwide
prospective audit of stoma complications within 3 weeks of
surgery Colorectal Dis 2007; 9: 834–8
38 Arumugam PJ, Bevan L, Macdonald L et al A prospective
audit of stomas analysis of risk factors and complications
and their management Colorectal Dis 2003; 5: 49–52
39 Saghir JH, McKenzie FD, Leckie DM et al Factors that predict
complications after construction of a stoma: a retrospective
study Eur J Surg 2001; 167: 531–4
40 Leenen LP, Kuypers JH Some factors influencing the
out-come of stoma surgery Dis Colon Rectum 1989; 32: 500–4
41 Pearl RK, Prasad ML, Orsay CP et al Early local
complica-tions from intestinal stomas Arch Surg 1985; 120: 1145–7
42 Gorfine SR, Bauer JJ, Gelerni IM Continent ileostomies In:
MacKeigan JM, Cataldo PA, eds Intestinal Stomas Principles,
Techniques, and Management St Louis: Quality Medical
Publishing, 1993; 154–87
43 Beck DE Abdominal wall modification for the difficult
stoma Clin Colon Rectal Surg 2008; 20: 71–5
44 Pemberton JH Management of conventional ileostomies
World J Surg 1988; 12: 203–10
45 Ien-Mersh TG, Thomson JP Surgical treatment of colostomy
complications Br J Surg 1988; 75: 416–8
46 Williams JG, Etherington R, Hayward MW et al Paraileostomy
hernia: a clinical and radiological study Br J Surg 1990; 77:
1355–7
47 Burns FJ Complications of colostomy Dis Colon Rectum
1970; 13: 448–50
48 Sjodahl R, Anderberg B, Bolin T Parastomal hernia in
rela-tion to site of the abdominal stoma Br J Surg 1988; 75:
339–41
49 Franks ME, Hrebinko RL Jr Technique of parastomal hernia
repair using synthetic mesh Urology 2001; 57: 551–3
50 Kish KJ, Buinewicz BR, Morris JB Acellular dermal matrix
(AlloDerm): new material in the repair of stoma site hernias
Am Surg 2005; 71: 1047–50
51 Rubin MS, Schoetz DJ Jr, Matthews JB Parastomal hernia Is
stoma relocation superior to fascial repair? Arch Surg 1994;
129: 413–8
52 Sugarbaker PH Peritoneal approach to prosthetic mesh
repair of paraostomy hernias Ann Surg 1985; 201: 344–6
53 Byers JM, Steinberg JB, Postier RG Repair of parastomal
her-nias using polypropylene mesh Arch Surg 1992; 127: 1246–7
54 Hopkins TB, Trento A Parastomal ileal loop hernia repair with marlex mesh J Urol 1982; 128: 811–2
55 Morris-Stiff G, Hughes LE The continuing challenge of parastomal hernia: failure of a novel polypropylene mesh repair Ann R Coll Surg Engl 1998; 80: 184–7
56 Rosin JD, Bonardi RA Paracolostomy hernia repair with Marlex mesh: a new technique Dis Colon Rectum 1977; 20: 299–302
57 Kasperk R, Klinge U, Schumpelick V The repair of large parastomal hernias using a midline approach and a pros-thetic mesh in the sublay position Am J Surg 2000; 179: 186–8
58 Tekkis PP, Kocher HM, Payne JG Parastomal hernia repair: modified thorlakson technique, reinforced by polypropylene mesh Dis Colon Rectum 1999; 42: 1505–8
59 Berger D, Bientzle M Laparoscopic repair of parastomal hernias: a single surgeon‘s experience in 66 patients Dis Colon Rectum 2007; 50: 1668–73
60 Kozlowski PM, Wang PC, Winfield HN Laparoscopic repair
of incisional and parastomal hernias after major genitouri-nary or abdominal surgery J Endourol 2001; 15: 175–9
61 Steele SR, Lee P, Martin MJ et al Is parastomal hernia repair with polypropylene mesh safe? Am J Surg 2003; 185: 436–40
62 Hedley AA, Ogden CL, Johnson CL et al Prevalence of over-weight and obesity among US children, adolescents, and adults, 1999–2002 JAMA 2004; 291: 2847–50
63 Livingston EH, Ko CY Socioeconomic characteristics of the population eligible for obesity surgery Surgery 2004; 135: 288–96
64 Gendall KA, Raniga S, Kennedy R, Frizelle FA The impact of obesity on outcome after major colorectal surgery Dis Colon Rectum 2007; 50(12): 2223–37
65 Duchesne JC, Wang YZ, Weintraub SL et al Stoma complica-tions: a multivariate analysis Am Surg 2002; 68: 961–6
66 Evans JP, Brown MH, Wilkes GH, Cohen Z, McLeod RS Revising the troublesome stoma: combined abdominal wall recontouring and revision of stomas Dis Colon Rectum 2003; 46: 122–6
67 Beck DE Abdominal wall modification for the difficult ostomy Clinics Colon Rectal Surg 2008: 16
68 Castillo E, Thomassie LM, Whitlow CW et al Continent ileostomy: Current experience Dis Colon Rectum 2005; 48: 1263–8
69 Steel MCA, Wu JE Late stomal complications Clinics Colon Rectal Surg 2002; 15: 199–207
70 Pokorny H, Herkner H, Jakesz R et al Mortality and compli-cations after stoma closure Arch Surg 2005; 140: 956–60
Trang 44 Operative and nonoperative therapy for chronic constipation
Harry T Papaconstantinou
Challenging Case
A 33-year-old women presents with constipation of 8 years
dura-tion She goes 7–10 days between bowel movements, despite
tak-ing multiple laxatives She tried extra dietary fiber, polyethylene
glycol, and lubiprostone, all without relief Her lack of bowel
activity is significantly impacting on her life style
Case ManageMent
A barium enema demonstrates normal anatomy A colonic transit
study demonstrates 20 markers evenly distributed throughout
the colon on day 5 A balloon expulsion test and anal manometry
were normal A diagnosis of colonic inertia is made and the
patient is offered a total abdominal colectomy with an ileorectal
anastomosis
intRODUCtiOn
Constipation is a common medical complaint resulting in over
2.5 million physician visits in the United States each year.(1)
Reports have indicated that constipation is a significant problem
with its prevalence ranging from 2 to 27%, and associated
medica-tion costs of over $500 million each year.(2) Stool weight, transit
time, and frequency of defecation correlate strongly with dietary
fiber intake It is estimated that the average daily consumption of
fiber in the United States is <20 grams, therefore, the prevalence
of constipation should be no surprise.(3, 4) Furthermore,
con-stipation adversely affects work-related productivity, educational
performance, and results in significantly lower quality of life and
higher psychological distress.(5, 6)
Constipation is not a specific disease, but rather a constellation
of symptoms Physicians typically define constipation in objective
terms of bowel movement frequency, specifically fewer than three
bowel movements per week However, constipation has different
meaning to individual patients, and may be described as the need
to strain to defecate, having hard stools, the inability to defecate
at will, incomplete evacuation, or the infrequent passage of stool
Regardless of the ambiguity of defining constipation, patients
fre-quently perceive the need for treatment due to advertising
por-traying “regularity” as the secret to health and well-being.(7, 8)
Therefore, it is important for the physicians to clarify patient’s
intended meaning, and to establish a more objective definition
for this subjective symptom Recently, a consensus of parameters
has been created and updated to more clearly define constipation
and is known as the Rome III criteria (Table 34.1).(9) The
estab-lishment of these parameters has provided more uniform
defini-tion of constipadefini-tion, and is a valuable tool to identify patients
that require treatment
Successful treatment of constipation requires the accurate
iden-tification of the underlying etiology of the symptom In most
patients, constipation is the direct result of specific medical
condi-tions (Table 34.2) or side effect of medicacondi-tions (Table 34.3) These
extracolonic causes can be easily identified in a careful and complete history and physical examination Constipation for these patients
is treated through medical management including alteration of their medications, prescription of laxatives, or dietary and lifestyle modifications A small group of patients will have a functional dis-order of the colon and anorectum resulting in constipation It is within this group of patients that colon and rectal surgeons can make the greatest impact, and is the focus of this chapter
Functional constipation can be divided into three groups: 1) slow-transit constipation, 2) pelvic floor dysfunction, and 3) combined slow-transit constipation and pelvic floor dysfunc-tion Slow-transit constipation, also known as colonic inertia,
is characterized by prolonged length of time for stool to pass through the colon.(10) Delay in stool transit is thought to be a primary dysfunction of the colonic smooth muscle (myopathy)
or innervation (neuropathy) Pelvic floor dysfunction results in evacuation disorders, and is characterized by either difficulty or inability to expel stool from the anorectum.(11) Common disor-ders of pelvic floor dysfunction include obstructive defecation, pelvic floor dyssynergia, outlet obstruction, or anismus.(11–13)
Table 34.1 Rome III diagnostic criteria for constipation.
Criteria must be fulfilled for the last 3 months.
Symptom onset at least 6 months before diagnosis 1) Must include 2 or more of the following.
a Straining ≥25% of defecation.
b Lumpy or hard bowel movements ≥25% of defecation.
c Sensation of incomplete evacuation ≥25% of defecation.
d Sensation of anorectal obstruction ≥25% of defecation.
e Manual maneuvers to facilitate bowel movement ≥25% of defecation.
f Fewer than 3 defecations per week.
2 Loose stools are rarely present without the use of laxatives.
3 Insufficient criteria for irritable bowel syndrome
Table 34.2 Medical conditions causing constipation.
endocrine and Metabolic neurogenic
Collagen Vascular and Musculoskeletal
Chronic renal failure Autonomic neuropathy Amyloidosis Diabetes mellitus Cerebrovascular disease Dermatomyositis
Milk-alkali syndrome Parkinson’s disease
Carcinomatosis Hirschsprung’s disease
Chaga’s disease
Trang 5improved outcomes in colon and rectal surgery
Recent advances in the analysis of colonic motility and pelvic floor
physiology have allowed for the identification and classification of
these two subtypes This is important as treatment modalities are
different Surgery is indicated for patients with slow-transit
consti-pation, while nonoperative treatment modalities, such as
biofeed-back therapy, are effective in patients with pelvic floor dysfunction
Patients with mixed conditions require correction of the pelvic
floor abnormality before undergoing an operation for slow-transit
constipation Patient selection is critical for treatment success
eValUatiOn anD DiagnOstiC stUDies
Initial evaluation of patients with constipation is a complex task
and starts with a careful history and physical examination Most
patients are reluctant to discuss these issues, and establishing a
trustworthy relationship is important to define the nature of bowel
dysfunction Constipated patients present with a constellation of
symptoms that include excessive straining to defecate, passage of
hard stools, the inability to defecate at will, digital disimpaction,
vaginal splinting, feeling of blockage at the anal opening,
incom-plete evacuation, and/or the infrequent passage of stool Details
of defecatory characteristics and habits are helpful and should
include stool frequency, stool consistency, stool size, and degree of
straining during defecation These patients should be asked about
precipitating events and the duration and severity of the problem
A dietary history should be obtained to assess of the amount of
daily fiber ingested and fluids consumed, as stool transit time and
frequency of defecation correlate strongly with dietary fiber intake
(3, 4) If the patient has already been treated by a referring
phy-sician it is important to know the number and types of laxatives
used, patient compliance, and whether there was any improvement
in symptoms A long history of constipation refractory to dietary
measures and laxative use is suggestive of functional constipation,
while a history of recent onset should alert the physician to seek
and exclude an organic cause such as neoplastic disease or stricture
A complete medical history will provide evidence of extracolonic
causes of constipation such as diabetes, hypothyroidism, or
cer-ebrovascular disease (Table 34.2) Detailed review of the patient’s
medication list will identify specific medications that are known to
cause constipation (Table 34.3)
A complete physical exam with specific emphasis on the abdo-men and perineum are important A normal physical exam is not uncommon A detailed anorectal exam starts with inspec-tion of the perianal skin Perineal sensainspec-tion and the anocutane-ous reflex are assessed by gently stroking the perineal skin with a cotton-tipped applicator stick Absence of a reflex contraction of the external anal sphincter indicates the presence of neuropathy
A digital rectal examination is performed to identify the presence
of an anorectal stricture, distal rectal mass, and the presence of stool or blood within the rectal vault Positive findings require further aggressive evaluation including colonoscopy During dig-ital examination, sphincter tone is assessed at rest and voluntary squeeze It is important to ask the patient to bear down as if to defecate This maneuver allows the examiner to determine relaxa-tion of the external anal sphincter and the presence of perineal descent Absence of these features is suggestive of pelvic floor dysfunction or dyssynergic defecation.(11) Vaginal and biman-ual examination should be performed to rule out rectocoele as a cause of outlet obstruction constipation
Routine evaluation of the colon is performed when there is a lack of identifiable causes of constipation This can be performed
by colonoscopy, barium enema, or CT colonography Although it has been reported that there is no increased incidence of colon or rectal neoplasia in patients with chronic constipation (14), rou-tine anatomic evaluation of the colon is performed to exclude tumors, strictures, and large bowel disease Endoscopic evalua-tion of the colon may reveal evidence of chronic laxative abuse (melanosis coli), diverticular disease with stricture, malignancy,
or colitis cystica profunda (internal rectal prolapse) Further work-up and treatment is dependent on the findings However, in the absence of anatomic causes of constipation, patients should
be initially treated with dietary and lifestyle modifications with
or without medications If initial treatment of constipation fails
to improve the patient’s symptoms, further investigational stud-ies are required to differentiate between functional constipation types It may seem intuitive that patients with slow-transit con-stipation would complain of infrequent bowel movements, while patients with pelvic floor dysfunction would report feelings of incomplete evacuation and excessive straining However, recent reports show that symptoms alone do not differentiate between the subgroups of functional constipation.(6, 15, 16) In fact, up
to 62% of patients with pelvic floor dysfunction report stool frequency of less than three bowel movements per week.(6) For this reason symptom assessment should be combined with objec-tive testing to better assess the nature of a patient’s complaint Physiologic studies of the colon (colonic transit study) and pelvic floor (anorectal manometry, balloon expulsion test, defecogram, and electromyography) are required to differentiate between slow-transit constipation, pelvic floor dysfunction, and patients with mixed features, and accurate diagnosis is critical for treat-ment success
Colonic Transit Studies
Self-reported stool frequencies correlate poorly with colonic transit, and patient’s recall of stool habits is often inaccurate indi-cating that subjective complaints are not sufficient to determine diagnosis Colonic transit studies provide objective assessment of
Table 34.3 Drugs associated with constipation.
Antipsychotics Cation-containing agents
Aluminum (antacids, sucralfate) Bismuth
Calcium (antacids, supplements) Iron supplements
Neurally active agents
Opiates Antihypertensives Ganglionic blockers Vinca alkaloids Calcium channel blockers
Others
Antihistamines Antiparkinsonian drugs Diuretics
Nonsteroidal anti-inflammatory drugs
Trang 6stool movement through the colon, and are critical tests to
iden-tify patients that will benefit from colectomy Two methods are
commonly used to measure colonic transit time and include
radi-opaque marker methods and scintigraphic techniques Studies
have shown that that these two tests correlate well to each other
and are sensitive for identifying colonic transit delays in patients
with slow-transit constipation.(17, 18) Objective documentation
of slow-transit constipation is critical for patient selection for
surgery, and has been shown to significantly improve outcomes
after colectomy (90% vs 67%).(19, 20)
Radiopaque Marker Test The most common and widely used
study of colonic transit time is the radiopaque marker method
This test was first described by Hinton et al in 1969, and since that
time several modifications have been described including single
and multiple capsule techniques.(21–23) This study is performed
by having the patient swallow a single capsule (Stizmarks; Konsyl®
Pharmaceuticles, Ft Worth, Texas) containing 24 radiopaque
mark-ers, and then tracking the markers by abdominal radiographs at
3 days and 5 days Patients are instructed to stop laxatives, cathartics,
and enemas for 2–7 days before ingestion of the capsule, and
dur-ing the test period to prevent false results In patients with normal
colonic motility, by day 5 of the test 19 (80%) or more of the
mark-ers will have passed through the colon and are either completely
evacuated or found in the rectum Patients with slow colonic transit
show the presence of 6 or more markers scattered throughout the
colon (Figure 34.1A) Patients with pelvic floor dysfunction such as
functional obstructive or dyssynergic defecation, exhibit retention
of 6 or more markers in the rectum or rectosigmoid region with a
near normal transit of markers through the colon (Figure 34.1B)
Although this test has been shown to be highly reproducible, when considering total abdominal colectomy for colonic inertia, it has been shown that patients have more favorable results if two marker studies have demonstrated slow-colonic transit times to confirm the diagnosis.(24)
Scintigraphic technique Scintigraphic defecography is another
modality available to study colonic transit Delayed-release cap-sules containing charcoal or polystyrene pellets radiolabeled with technetium-99m or indium-111 are coated with a pH-sensitive polymer methacrylate The coating dissolves in an alkaline pH within the terminal ileum and cecum Colonic distribution of the radioisotope is determined on scans taken 24 and 48 hours after capsule ingestion, and is highly sensitive and specific for identi-fying slow colon transit.(25, 26) Colon transit measurements by radiopaque markers and scintigraphic techniques correlate well with each other, and are sensitive for identifying colonic transit delays in patients with slow transit constipation.(18)
When a diagnosis of slow-transit constipation is made, the physician must be aware of specific conditions that may be asso-ciated with this functional disorder and adversely affect surgical treatment with colectomy First, slow-colonic transit constipation may be a component of a generalized gastrointestinal disorder such as panenteric intertia A recent review has suggested that patients with this generalized gastrointestinal motility disorder have significantly diminished long-term success rate after colec-tomy for slow-transit constipation.(27) This is supported by the high rate of recurrent small-bowel obstruction (70%) in patients with panenteric intertia.(28) Collectively, these data suggest that whole gut transit studies should be considered before colectomy
Figure 34.1 Colonic transit study using single capsule radiopaque markers Abdominal radiographs shown were taken 5 days after capsule ingestion The presence of
>6 marks scattered throughout the colon is diagnostic for slow colonic transit (A) Retention of markers within the rectum and rectosigmoid region suggests pelvic outlet obstruction (B).
Trang 7improved outcomes in colon and rectal surgery
for slow-transit constipation, and include gastric emptying,
upper gastrointestinal small bowel follow-trough, and
choly-cystokinnin hepatic dimethyliminodiacetic acid (CCK-HIDA)
scan Colectomy in patients with a global gastrointestinal motility
disorder is not likely to improve their symptoms and is
discour-aged Second, in patients with findings suggestive of pelvic floor
dysfunction, up to two-thirds will exhibit mixed pattern
consti-pation with both slow transit and obstructive delay.(29) Further
pelvic floor physiology testing and treatment of the pelvic floor
dysfunction is required before colectomy to improve outcomes
and avoid treatment failure
Pelvic Floor Physiology Tests
Patients with functional constipation due to pelvic floor
dysfunc-tion and obstructive defecadysfunc-tion have difficulty with evacuadysfunc-tion
of rectal contents Normal evacuation requires the involuntary
relaxation of the internal anal sphincter as well as the voluntary
relaxation of the external anal sphincter and pelvic floor
mus-cles Failure of this coordinated effort results in outlet obstructive
symptoms Pelvic floor physiology testing can identify specific
disorders such as blunting of the rectal anal inhibitory reflex
(RAIR), paradoxical puborectalis contraction, and anatomic
abnormalities that cause outlet obstruction Common tests used
to identify these disorders include anorectal manometry, balloon
expulsion test, defecography, and electromyography
Anorectal Manometry Anorectal manometry provides a
comprehensive assessment of anal sphincter muscle tone and
the anorectal sensory response to different stimuli This test is
useful in the evaluation of patients with obstructive defecation,
and helps to detect abnormalities during attempted defecation
such as pelvic floor dyssynergia or anismus.(30) The complete
manometric evaluation of the anorectum includes determination
of the resting pressure, squeeze pressure, length of the
high-pres-sure zone, rectal compliance, RAIR, and the ability of the internal
anal sphincter to relax with straining In normal defecation, as
rectal pressure rises there is a synchronized fall in the internal
anal sphincter pressure A blunted rectal sensation is a common
finding in patients with functional obstructive defecation.(31)
Absence of the RAIR suggests secondary causes of constipation
such as Hirschsprung’s disease, Chagas disease, or previous
sur-gery.(32–34) External sphincter muscle relaxation for the
elimina-tion of stool is a learned response that is under voluntary control
Inability to perform this coordinated movement represents the
chief pathophysiologic abnormality in patients with dyssynergic
defecation and anismus, and may be due to impaired rectal
con-traction, paradoxical puborectalis concon-traction, or impaired anal
relaxation.(11, 35) Anorectal manometry has been shown to be
inaccurate in the diagnosis of paradoxical puborectalis and
dys-synergic defecation, and further testing with balloon expulsion
test and electromyography should be performed to assist in
diag-nosis.(36)
Balloon Expulsion Test The balloon expulsion test is a
func-tional evaluation of the patient’s ability to defecate In this test,
a latex balloon is filled with 60 ml of warm water or air within
the rectum The patient is asked to expel the balloon in a
pri-vate bathroom while sitting on the toilet The physiologic
posi-tion and privacy allow this method to more closely approximate
normal evacuation Normal subjects can expel the balloon within
1 minute.(37) While seeming trivial, it is important that patients
do not flush the balloon as it can severely damage the plumbing Inability to expel the balloon is suggestive of functional outlet obstruction such as paradoxical puborectalis contraction and dyssynergic defecation The balloon expulsion test is a simple and accurate test that has been shown to have a high specificity (89%) and negative predictive value (97%) for excluding pelvic floor dyssynergia as a cause of constipation.(36, 38, 39)
Defecography Defecography is the real time imaging of
patient defecation, and provides dynamic characterization of the interaction between the anal sphincter complex and the rectum
in an attempt to define abnormalities in the pelvic floor It pro-vides information on the anatomic and functional changes of the anorectum during defecation, and is effective in differentiating between anatomic and functional causes of obstructive defeca-tion Before the test is performed, the patient is cleansed of stool using an enema Barium paste is placed into the rectum, and with the aid of fluoroscopy the process of defecation is video-recorded Static and real-time dynamic radiographic images are obtained during the process of defecation Specific measurements such
as the anorectal angle, perineal descent, and puborectalis length during stages of squeeze and push are calculated.(40) Patients with paradoxical puborectalis contraction and dyssynergic def-ecation will exhibit failure of the anorectal angle to open, per-sistence of the puborectalis impression on the rectum, and poor rectal emptying of the barium paste.(41–43) It has been shown that patients with a diagnosis of paradoxical puborectalis on defecography have a high frequency of constipation symptoms (44) Defecography is reported to be too sensitive for paradoxical puborectalis contraction and dyssynergic defecation leading to a high false-positive diagnosis, but this test does have the advantage
of evaluating any coexistent pelvic floor pathology.(45) Anatomic causes of obstructive defecation are readily identifiable during defecography and include internal intussusception of the rec-tum, rectocoele, enterocoele, and sigmoidocoele The physiologic importance of these findings is often unclear, and the surgeon must determine their significance to individual patient symp-toms and complaints to determine need for surgical repair
Electromyography Surface electromyography (EMG) can be
performed by anal plug, intraanal sponge, or concentric needle technique to diagnose patterns of anal sphincter and pelvic floor muscle dysfunction Electrodes are used to record action potentials derived from motor units within contracting muscles Recordings are taken at rest, squeeze, and push In normal patients, the act
of defecation and push is accompanied by a decrease in motor unit activity signifying relaxation of the anal sphincter complex (Figure 34.2A) Patients with dyssynergic defecation and para-doxical puborectalis contraction exhibit increased motor unit activity during push indicating an increase in anal sphincter complex contraction during defecation (Figure 34.2B) Studies have shown that the negative predictive value for this test is high (91%) indicating EMG can accurately rule out paradoxical pub-orectalis contraction; however, the positive predictive value is quite low when compared with defecography.(46–48) This sug-gests the need for comprehensive physiologic testing to accurately diagnose paradoxical puborectalis contraction
Trang 8MeDiCal tReatMent OF COnstiPatiOn
Initial treatment of functional constipation regardless of type
is patient education, dietary and lifestyle modifications, and a
trial of medical management Education of the patient is
criti-cal and should include explanation of normal physiologic bowel
patterns.(49) It is important to communicate to the patient that
their symptoms will not be corrected overnight, and
modifica-tions of the treatment regimen may be required In many patients
a dietary and medication log can be helpful to accurately
iden-tify fiber and water consumption, and medication compliance
A daily diary to record bowel movements, stool characteristics,
and associated abdominal symptoms is useful when assessing
responses to treatment Patients should be encouraged to
recog-nize and respond to the urge to defecate Most patients who have
a normal bowel pattern usually empty stools at approximately
the same time every day suggesting this is in part a conditioned
reflex.(50) Ritualizing bowel habits may be useful to establish a
regular pattern of bowel movement and should be coordinated
with physiologic events that stimulate colonic motility (walking
and postprandial gastrocolic response).(11) General measures
such as adequate hydration and regular exercise has overall health
benefit; however, there is no evidence to support success in the
treatment of chronic constipation, except in situations of
dehy-dration.(51, 52) Indirect evidence exists, as epidemiologic
stud-ies suggest that sedentary people are three times more likely to
report constipation.(53)
A diet high in fiber content increases stool weight and accelerates
colonic transit time.(54) In contrast, a diet that is deficient in fiber
may lead to constipation.(54, 55) Consensus exists that empiric
treatment for constipation with a high-fiber diet is inexpensive
and effective therapeutic intervention for addressing
constipation-related bowel dysfunction.(56, 57) There is a clear dose response
between daily fiber intake and fecal output that is enhanced by
increased fluid intake Dietary supplements such as bran may cause
significant amounts of abdominal bloating and discomfort, which
may decrease patient compliance Gradual increase in dose may
minimize these symptoms Psyllium seed, methylcellulose, and cal-cium polycarbophil are bulk-forming laxatives that absorb water into the colonic lumen and increases fecal mass, which in turn stimulates motility and reduces colon transit time.(58) A literature review of articles dealing with 18 double-blind studies related to constipation found that dietary fiber supplements or bulk laxa-tives resulted in an average increase of 1.4 (95% CI, 0.6–2.2) bowel movements per week, while laxative agents other than bulk showed
an increase of 1.5 (95% CI, 1.1–1.8) bowel movements per week (59) Others have shown that fiber has limited value in patients with slow-transit constipation and pelvic floor dysfunction as patients with these conditions did not respond effectively to dietary sup-plementation with 30 grams of fiber per day.(56) Conversely, patients without an underlying motility disorder either improved
or became asymptomatic with fiber therapy Collectively, these data suggest that therapeutic trial of dietary fiber should be con-sidered as initial treatment for patients with constipation, although fiber supplements administered alone are probably more effective
in normal transit or fiber deficiency constipation than slow transit constipation or pelvic floor dysfunction.(27)
Failure of fiber therapy requires alternative choices of laxative medications A list of common medications used to treat consti-pation is shown in Table 34.4 With so many potential options available, the choice of laxative therapy is subject to patient pref-erence, and physician opinion and consensus.(60, 61) Although there are a variety of preparations available, the laxatives that are frequently recommended include milk of magnesia, lactulose, sorbitol, senna compounds, bisacodyl, and polyethylene glycol preparations
Milk of magnesia, magnesium citrate, and sodium phosphate are saline laxatives that are poorly absorbed or nonabsorbed osmotic preparations that result in secretion of water in the intestines to maintain isotonicity with plasma.(62) Use of these agents is not recommended in patients with cardiac and renal dysfunction because excessive absorption may lead to electrolyte abnormalities and volume overload When ingested as hypertonic
Figure 34.2 Electromyographic tracings in a patient with normal defecation (A)
and paradoxical puborectalis contraction (B) Black arrows indicate push phase that normally corresponds with muscle relaxation and lower amplitude waves (R rest; S strain; P push).
Trang 9improved outcomes in colon and rectal surgery
solutions, there is a rapid osmotic equilibration that occurs, and
overuse may result in significant dehydration.(62)
Lactulose and sorbitol are nonabsorbable disaccharides that are
effective osmotic laxative agents Lactulose is a known substrate
for colonic bacterial fermentation with resultant production of
hydrogen, methane, carbon dioxide, water, acid and short-chain
or volatile fatty acids.(63) These products act as osmotic agents
and also stimulate intestinal motility and secretion Lactulose has
been shown to increase stool frequency in chronically constipated
patients (64); however, abdominal bloating, discomfort, and
flatulence are common side effects of this medication and may
decrease patient compliance Sorbitol is a poorly absorbed sugar
alcohol that produces similar effects In a trial of constipated men
over the age of 65, sorbitol administered as a 70% syrup (10.5 g/15
mL; 15 to 60 mL daily) was equivalent to lactulose in improving
symptoms.(65) Furthermore, it was cheaper and better tolerated
during a 4-week trial
High-molecular-weight polyethylene glycol (PEG) is a large
poly-mer with substantial osmotic activity that obligates intraluminal
water.(66) It is routinely used with a balanced electrolyte solution
for colon cleansing as polyethylene glycol electrolyte lavage solution
(PEG-ELS) These solutions are safe and effective, and are routinely
used for bowel preparations for colonoscopy and bowel surgery
(67) Other forms have been effectively used as laxatives for the treat-ment of constipation PEG 3350 (MiraLax, Braintree Laboratories, Braintree, MA) is a large chemically inert polymer that also functions
as an osmotic laxative It does not contain salts that can be absorbed, and has been shown not to change measured electrolytes, calcium, glucose, blood urea nitrogen (BUN), creatinine, or serum osmolal-ity.(68) A recent randomized controlled multicenter trial has shown effectiveness of 17g of PEG 3350 laxative over a dextrose placebo, with greatest efficacy during the second week of the therapy.(69) An 8-week, double blind, placebo-controlled study showed that PEG
3350 administered to patients with chronic constipation increased stool frequency and accelerated left colonic transit, without induc-ing abdominal cramps or bloatinduc-ing In a long-term multicenter study
of PEG 4000, 14.6 g twice a day improved stool frequency, reduced straining effort, softened stools, and decreased the need for oral laxa-tives and enemas when compared with placebo (70); however, there was a high dropout rate (30% PEG 4000 and 60% placebo) which raises concerns about efficacy and tolerance
Stimulant laxatives The stimulant laxatives have effects on
mucosal electrolyte transport and gut motility Commonly used laxatives in this category include bisacodyl and senna Abdominal discomfort and cramping are common side effects of these agents Bisacodyl produces defecation within 6 to 8 hours of taking the
Table 34.4 Medications commonly used for constipation.
type generic name trade name Dosage Mechanism of action
Fiber
Increase stool bulk Decrease colonic transit Increase gastrointestinal motility
Calcium polycarbophil Fibercon 2–4 tabs qd
stool softener Docusate sodium Colace 100 mg bid ineffective for constipation
Osmotic
agents
Lactulose Chronulac 15–30 mL qd or bid Accelerate colonic transit
suppository glycerine Up to daily Rectal stimulation
Bisacodyl Dulcolax 10 mg daily
Stimulants
Bisacodyl Dulcolax 10 mg po up to 3x/wk Increase intraluminal fluid Antraquinones Senokot 2 tabs qd to 4 tabs bid Stimulation myenteric plexus
saline
laxatives Magnesium
Milk of Magnesia 15–30 ml qd or bidn Osmotic increase fluid small bowel
stimulate CCK Decrease colon transit time haley’s M-O 15–30 ml qd or bid
Magnesium citrate 1 bottle lubricant Mineral oil 15–45 ml stool lubricantn
Enemas
colon; mechanical lavage
tid = three times a day; qd = daily; bid = twice a day.
Trang 10tablet, or 15 to 30 minutes after the suppository It is believed
to exert its effect by inducing high amplitude propagated
con-tractions of the bowel, and is an effective rescue medication for
chronic constipation.(27) Senna is member of the anthraquinone
family of laxatives that are common constituents of herbal and
over-the-counter laxatives They are metabolized in the colon by
bacteria into their active forms In a trial of elderly nursing home
residents (n = 77), a senna and fiber combination was reported
to be better than lactulose in improving stool frequency, stool
consistency, and ease of passage.(71) Furthermore, the senna and
fiber combination was 40% cheaper than lactulose therapy
Side effects of these laxatives include allergic reactions,
electro-lyte imbalance, melanosis coli, and “cathartic colon” Melanosis
coli is a result of chronic ingestion of anthraquinone-containing
laxatives This condition is an abnormal pigmentation of the
colonic mucosa that is caused by the accumulation of
apop-totic epithelial cells that are phagocytosed by macrophages.(72)
“Cathartic colon” is an alteration of colon anatomy that was
believed to be associated with chronic stimulant laxative use
Barium enema findings included colonic dilation, loss of
haus-tral folds, strictures, colonic redundancy, and wide gaping of the
ileocecal valve.(73) Initially, it was attributed to the destruction of
myenteric plexus neurons by laxatives (74); however, more recent
studies do not confirm those findings.(75) Current evidence
sup-ports the safety of currently available laxatives at recommended
doses for long-term use Finally, anthraquinones have been
pro-posed to have mutagenic effects and produce tumors in animal
models Several cohort studies and one case-control study failed
to find an association between anthraquinones and colorectal
adenomas or carcinoma.(76)
Other drugs Patients with severe slow-transit constipation
may not respond to medical therapies described above Ideally,
slow-transit constipation should be treated with an agent that
restores normal colonic function Medications such as
secretago-gues (lobiprostone, cholchicine, and misoprostol) and prokinetic
agents (tegaserod, alvimopan, linaclotide) are currently under
clinical trials for the treatment of constipation, and show promise
for patients with slow-transit constipation
Lubiprostone is an oral bicyclic fatty acid that activates the type
2 chloride channels that are located on the intestinal epithelial
cell leading to an active secretion of chloride in the intestinal
lumen.(77) In healthy humans, this drug has been shown to slow
gastric emptying, but accelerated small bowel and colonic transit
time at 24 hours.(78) In a randomized control study with intent
to treat analysis, lubiprostone significantly increased the number
of spontaneous bowel movements per week, improved straining
effort, improved overall satisfaction with bowel habits, and
pro-duced softer stools when compared with placebo.(79)
Colchicine is a microtubule formation inhibitor that is
com-monly used to treat gouty arthritis A significant side effect of
colchicine is diarrhea In an open labeled study of 7 patients with
normal transit constipation, colchicine (0.6 mg orally 3 times
per day) increased stool frequency and accelerated colon
tran-sit time.(80) Furthermore, patients reported reduced symptoms
of abdominal pain, nausea, and bloating However, long-term
use may be associated with neuromyopathy, and its use for
chronic constipation is not supported The prostaglandin E1
analog misoprostol (1200 µg/d) has been shown to increase stool frequency and accelerate colonic transit (81); however, the drug is expensive and its beneficial effects appear to decline over time Tegaserod is a serotonin 5-HT4 receptor partial agonist that has been shown to increase gastic emptying and colonic transit time.(82) Large randomized controlled trials in the United States and Europe have reported that tegaserod increases the number
of complete spontaneous bowel movements per week, relieves constipation-related symptoms, and improves overall bowel sat-isfaction.(79, 83) However, recent reports of 0.01% incidence
of coronary and cerebrovascular events have suspended sales
of tegaserod Another drug, alvimopan, is a peripherally acting µ-opioid receptor antagonist This drug does not cross the blood-brain barrier, and therefore, does not inhibit the analgesic effect
of opioids A physiologic study of alvimopan has shown that this drug reverses opioid-induced delayed colonic transit in healthy subjects.(84) These data were verified in another randomized trial of opioid-induced bowel dysfunction, and has been shown
to be effective in the treatment of acute postoperative ileus.(85, 86) Further studies are necessary to determine efficacy of alvimo-pan on chronic constipation
BiOFeeDBaCK theRaPY
In patients with constipation due to pelvic floor dyssynergia, bio-feedback therapy is frequently recommended after failure of con-servative management described above.(87) Biofeedback therapy uses electronically amplified recordings of pelvic floor mus-cle contractions (EMG) or anorectal pressure tracings to teach patients how to relax pelvic floor muscles and to strain more effectively when they defecate.(12) The purpose of this therapeu-tic modality is to restore a normal pattern of defecation by using
an instrument-based education program The primary goals are
to correct the underlying dyssynergy that affects the abdominal, rectal, and anal sphincter muscles, and to improve the rectal sen-sory perception A series of training sessions are used to teach diaphragmatic breathing techniques to improve abdominal push-ing effort and to synchronize this with anal relaxation Visual or auditory feedback is used to provide the patent input regarding performance during attempted defecation maneuvers
Studies on biofeedback therapy for the treatment of pelvic floor dyssynergia have been reviewed extensively.(88, 89) These reviews suggest that two-thirds of these patients benefit from biofeedback training, with individual studies reporting a 30 to 100% success rate; however, attempts to draw definitive conclu-sions about the usefulness and effectiveness of biofeedback for the treatment of pelvic floor dyssynergia-type constipation are difficult due to the lack of adequately controlled trials of suffi-cient sample size.(87) In a recent review of biofeedback therapy for pelvic floor dyssynergia, 4 of 27 (<15%) studies in the adult population were controlled, and only one well-controlled study had a sample size that was sufficient to provide meaningful statis-tical conclusions.(87)
Biofeedback therapy for dyssynergic-type constipation is directed
at coordinating pelvic floor muscle relaxation with intraabdominal pressure to generate an effective propulsive force Instrumentation protocols in these patients require either EMG monitoring of muscle tone or anorectal pressures for biofeedback training To