Surgical Atlas of pediatric otolaryngology - part 7 pdf

particu-Figure 22–9 Fourth branchial pouch sinus originating in the piriform apex dashed lines, caudal to the superior laryngeal nerve SLN, and terminating as a small cyst in the superio

FOURTH BRANCHIAL POUCH SINUS

The fourth branchial pouch sinus is an uncommon congenital anomalywith two characteristic clinical presentations:

1 Neonatal neck mass A neonate presents with a lateral neck cyst or

abscess associated with actual or impending airway compromise Themass mimics a cystic hygroma, and may contain air or increase in sizeduring crying or Valsalva

2 Recurrent deep neck infection A child, adolescent, or occasionally an

adult, presents with recurrent deep neck abscess or suppurative roiditis, despite several attempts at drainage or neck exploration.The fourth branchial pouch sinus is not a complete fistula, but rather abrief, internal tract originating in the piriform sinus After exiting the pyri-form apex, caudal to the superior laryngeal nerve (Figure 22–9), the tractdescends translaryngeally under the thyroid ala to emerge beneath the infe-rior constrictor muscle, and exit the larynx near the cricothyroid joint.Nearly all reported sinuses have been left sided

particu-Figure 22–9 Fourth branchial

pouch sinus originating in the

piriform apex (dashed lines),

caudal to the superior laryngeal

nerve (SLN), and terminating as

a small cyst in the superior pole

of the thyroid gland The sinus

tract is near the recurrent

laryn-geal nerve (RLN) at the

cricothyroid joint.

• Acutely infected sinuses are treated with antibiotics, and incision anddrainage if necessary; definitive excision is delayed several weeks untilinflammation has resolved

• Perioperative antibiotics are given routinely

• Equipment is available for direct microlaryngoscopy to examine the lateral piriform apex for a sinus tract

ipsi-Anesthesia and Preparation

• General anesthesia with orotracheal intubation is required

• The patient’s neck is extended and draped from the clavicle to the chin

Procedure

• Direct laryngoscopy is performed and the ipsilateral piriform apex isinspected for a sinus tract opening If a distinct opening is found, twooptions exist:

1 Endoscopic cauterization The sinus tract is obliterated by endoscopic

cauterization using an insulated needlepoint electrocautery, and theprocedure is concluded Preliminary results with limited follow-uphave been favorable Cauterization is at low power and limited to thesuperficial mucosal layer, which leads to scarring and closure of thesinus tract with low risk of perforation

2 Open surgical excision The sinus tract is excised retrograde, beginning

with complete exposure of the piriform fossa Recurrence has notbeen reported with this approach, but morbidity is higher than withcauterization In contrast, excising only the extralaryngeal portion ofthe tract almost guarantees recurrence

• External excision begins by exposing the thyroid ala and carotid sheath,which allows the operation to begin in a region relatively free of postin-flammatory fibrosis

1 An incision is made along the anterior border of the mastoid muscle, from superior aspect of the thyroid cartilage to thelevel of the cricoid cartilage (Figure 22–10)

sternocleido-2 The sternocleidomastoid muscle is retracted, exposing the posterioredge of the lateral thyroid cartilage, with the attached inferior con-strictor muscle

3 If a tract is discovered exiting from the thyrohyoid membrane, rostral

to the superior laryngeal nerve, the diagnosis of a third pouch sinus isconfirmed and exposure of the piriform fossa is not required Thetract is ligated and dissected retrograde

4 If a tract or fibrosis is not apparent near the thyrohyoid membrane, afourth pouch sinus is likely, and the piriform fossa is exposed asdescribed below

• To expose the piriform fossa, a vertical incision is made along the rior edge of the lateral thyroid cartilage and inferior cornu down to andthrough the perichondrium The inferior constrictor is separated poste-

poste-riorly, hugging the cartilage closely and elevating the perichondriumaround the posterior edge and on the medial side sufficiently to detachthe inferior constrictor muscle.

• A tracheal hook distracts the posterior edge of the thyroid ala anteriorly(Figure 22–11), and the facet-like joint between the inferior cornu andthe cricoid cartilage is separated To avoid recurrent laryngeal nerveinjury, the joint is divided as close to the inferior cornu as possible

• The thyroid perichondrium is elevated anteriorly to expose the

posteri-or thyroid cartilage A 1-cm strip of posteriposteri-or thyroid ala is excised,exposing the underlying piriform sinus

• The fourth pouch sinus tract is ligated from its origin at the piriform apexand any pharyngeal defect is repaired with pursestring closure Recur-rence is likely if the pharyngeal connection is incompletely ligated

• The sinus tract is then excised retrograde, ending with a surroundingellipse of skin if a fistula was present

♦ Part of the superior pole of the thyroid gland may be included if essary (see Figure 22–11), but the superior parathyroid gland should

nec-be preserved

♦ If the tract descends paratracheally, exposure of the recurrent geal nerve is necessary to prevent injury When the nerve cannot beidentified because of inflammation or scarring, the excision shouldend at the cricothyroid region to prevent nerve injury

laryn-• A Penrose rubber drain is inserted and the incision is closed in layers

Postoperative Care

• Perioperative antibiotics are continued for 24 hours

• The drain is removed on the first postoperative day unless drainage isexcessive

FIBROMATOSIS COLLI

Fibromatosis colli (sternomastoid tumor of infancy) is thought to represent

an injury to the sternomastoid muscle, incurred either in utero or duringdelivery The deformity is usually noted at birth or within the first 10 days

of life, and may be associated with congenital hip dislocation A firm massbecomes palpable in the muscle and progresses to a maximal size (1-3 cm),generally within 1 month The head is usually tilted toward the side of theshortened muscle, and the chin rotates toward the opposite (normal) side.Fine needle aspiration aids in diagnosis

If left untreated, the condition may cause developmental asymmetry ofthe face and ocular imbalance Conservative management, which consists

of range of motion exercises, is generally successful in resolving the lem; however, surgery may be necessary in rare cases Other evidence ofinjury should be looked for, such as a fracture of the clavicle or cervicalspine injury or abnormality

prob-Indications

• A mass within the body of the sternomastoid muscle that does notresolve with aggressive physical therapy, consisting of passive range ofmotion exercises performed by the parent three to four times daily

• Long standing torticollis in older children may benefit from tenotomy

or release of the shortened sternomastoid muscle Evaluation of theunderlying cervical spine should be performed to detect any abnormal-ities

Anesthesia and Preparation

• General endotracheal anesthesia is necessary

• The patient’s neck is extended, and the head is rotated away from theside of the torticollis to make the mass as prominent as possible

• The neck is prepped from the clavicle to the chin

Procedure

• A horizontal incision is created over the mass and carried through thesubcutaneous tissue (Figure 22–12)

• The greater auricular nerve is preserved if possible

• The mass can generally be separated from normal muscle fiber withpreservation of the portion of the sternomastoid muscle that is notinvolved with the fibrosis The accessory branch to the sternomastoidmuscle should also be preserved

• The incision is closed immediately in the standard fashion

Postoperative Care

• Postoperatively, the patient performs range of motion exercises to tain the release that has been surgically created

main-Kennedy TL Cystic hygroma-lymphangioma: a rare and still unclear entity Laryngoscope 1989;99Suppl:1–10.

Landing BH, Farber S Function of the cardiovascular system In: Atlas of tumor pathology, ington (DC): Armed Forces Institute of Pathology; 1956 p

Wash-May J, D’Angelo AJ Jr The facial nerve and the branchial cleft surgical challenge Laryngoscope1989;99:564–5

Mickel RA, Calcaterra TC Management of recurrent thyroglossal duct cysts Arch OtolaryngolHead Neck Surg 1983;109:34–6

Prasad S, Grundfast G, Milmoe G Management of congenital preauricular pit and sinus tract inchildren Laryngoscope 1990;100:320–1

Ricciardelli EJ, Richardson MA Cervicofacial cystic hygroma: patterns of recurrence and ment of the difficult case Arch Otolaryngol Head Neck Surg 1991;117:546–53

manage-Riechelmann H, Muehlfay G, Keck T, et al Total, subtotal, and partial surgical removal of facial lymphangiomas Arch Otolaryngol Head Neck Surg 1999;125:643–8

cervico-Rosenfeld RM, Biller HF Fourth branchial pouch sinus: diagnosis and treatment Otolaryngol HeadNeck Surg 1991;105:44–50

Sedwick CE, Walsh JF Branchial cysts and fistulas: a study of seventy-five cases relative to clinicalaspects and treatment Am J Surg 1952;83:3–8

Simpson RA Lateral cervical cysts and fistulas Laryngoscope 1969;79:30–58

Sistrunk WE The surgical treatment of cysts of the thyroglossal tract Ann Surg 1920;71:121–4.Tom LW, Handler DS, Wetmore RF, Potsic WP The sternocleidomastoid tumor of infancy Int JPediatr Otorhinolaryngol 1987;13:245–55

Tom LW, Rossiter JL, Sutton LN, et al Torticollis in children Otolaryngol Head Neck Surg1991;105:1–5

Woodman D A modification of the extralaryngeal approach to arytenoidectomy for bilateral tor paralysis Arch Otolaryngol 1946;43:63–5

abduc-Work WP Newer concepts of first branchial cleft defects Laryngoscope 1972;82:1581–93

S ALIVARY G LAND S URGERY

Michael J Cunningham, MD

PAROTIDECTOMY

During childhood, the parotid glands and paraparotid lymph nodes aresubject to infection, inflammation, and neoplasia Vasoformative and con-genital cystic lesions often are clinically apparent Conversely, chronicinflammation may present as an indolent firm mass indistinguishable from

a benign or malignant neoplasm Serology, skin tests, and radiologic ing (contrast sialography, ultrasonography, computed tomography, or mag-netic resonance imaging) may suggest, but typically cannot confirm, thespecific underlying disease process

imag-Fine-needle aspiration (FNA) biopsy has a limited role in diagnosingsolid parotid masses If the child needs general anesthesia for needle biop-

sy, then excisional biopsy will yield greater histopathologic information.More importantly the definitive treatment of many inflammatory and neo-plastic causes of solid parotid masses in children is surgical excision Exci-sional biopsy, or superficial parotidectomy, is therapeutic and diagnostic insuch circumstances As in adults, neither incisional biopsy nor the isolatedenucleation of solitary parotid lesions is recommended Total parotidecto-

my is rarely necessary in children

Indications

• Solid parotid mass of unknown or uncertain etiology

• Chronic recurrent parotitis

• First and second branchial system anomalies

• Vasoformative lesions

Anesthetic Considerations and Preparation

• The procedure is performed under general anesthesia

• Paralytic agents are avoided to allow for intraoperative facial nerve ulation

stim-• Informed consent regarding the risk of facial nerve injury is an absolutenecessity

• The child is positioned supine with the head turned toward the volved side The operative field is draped with sterile transparent plasticsheeting to provide exposure of the entire face on the involved side,including the corners of the eye and mouth (Figure 23–1) This allowsfor the intraoperative assessment of facial nerve function.

(Figure 23–2B).

♦ In infants and very young children, a single curved incision, beginning

1.5 to 2 cm below the mandible and extending posterior and

superi-or over the mastoid prominence, repsuperi-ortedly protects the superficially

located facial nerve (Figure 23–2C)

Figure 23–1 The patient is

posi-tioned so that facial nerve

func-tion can be assessed.

• The skin flaps are elevated in a plane of dissection deep to the neous tissues and superficial to the investing fascia of the parotid gland.The anterior margin of elevation is the parotid gland’s anterior border toavoid inadvertent transection of small facial nerve branches emergingfrom the gland over the masseter muscle (Figure 23–3).

subcuta-• Posteroinferior flap dissection is performed in the subplatysmal planeuntil the anterior border of the sternocleidomastoid muscle is clearlyidentified

♦ Care is particularly necessary in infants and young children because

limited posterior development of the parotid gland may expose alarge portion of the facial nerve (Figure 23–4)

♦ In older children, the tail of the parotid gland often needs to be

separat-ed from the sternocleidomastoid muscle Both the greater auricularnerve and the posterior facial (retromandibular) vein are typicallyencountered and need to be sacrificed for gland retraction and exposure

• Using both superior traction on the earlobe and anterior traction on theparotid gland, blunt dissection along the tragal cartilage and adjacentmastoid bone allows separation of the small fibrous bands that attach theposterior border of the parotid gland to these structures (Figure 23–5)

Figure 23–3 Elevation of the anterior and posteroinferior flaps

♦ The goal of progressive medial dissection in this fashion is to

identi-fy the main trunk of the facial nerve as it emerges from the toid foramen

stylomas-♦ In older children and adolescents, the location of the facial nerve can be

anticipated approximately halfway between the tip of the mastoidprocess and a triangular extension of the cartilaginous external earcanal, the so-called pointer

1 Immediately before encountering the facial nerve, the poroparotid fascia often arises from the tympanomastoid fissure as

tem-a firm btem-and extending into the ptem-arotid gltem-and

2 Conservative use of the nerve stimulator during this portion of theprocedure helps to distinguish fascia from nerve

3 Hemostasis is crucial for visualization purposes; bipolar tion in a moist field is advocated to decrease the likelihood ofcautery-induced neural damage

cauteriza-♦ In infants and young children, limited mastoid development results in

less well-defined bony landmarks for facial nerve identification

(Fig-ures 23–6 A and B) In addition, some of the inflammatory

condi-tions necessitating parotidectomy in children pathologically involvethe external auditory canal, creating scarring in this region and plac-ing the main trunk of the facial nerve in further jeopardy

1 An alternative method of finding the facial nerve in such stances is to follow the anterior border of the sternocleidomastoidmuscle superiorly to its temporal bone insertion and to locate theposterior belly of the digastric muscle just deep to this insertion site

circum-2 Using blunt dissection and working anteriorly, the facial nervetrunk typically can be found within the triangle formed by thesetwo muscles and the cartilaginous ear canal (Figure 23–7)

• In revision surgical procedures with extensive cervical scarring, an native approach is to use the retroauricular extension of a Y-shaped skin

alter-incision (see Figure 23–2B ) A limited mastoidectomy is then

per-formed to provide access to the facial nerve in the descending portion ofthe fallopian canal prior to its skull base exit

• Once the main trunk of the facial nerve is clearly identified, it is lowed anteriorly to the pes anserinus

fol-♦ In adolescents and older children, this requires dissection into the

parotid gland

♦ In infants, the pes may actually be in the retromandibular region

out-side of the parotid gland proper (see Figure 23–4)

• A plane of cleavage through the parotid gland is developed as proximal

to distal dissection of both the upper zygomaticotemporal and lower vicofacial divisions of the facial nerve is performed (Figure 23–8)

cer-♦ Branches of the posterior facial (retromandibular) vein require tion during this portion of the procedure, as does the parotid duct ifidentified and transected

liga-♦ Once the temporal, zygomatic, buccal, and mandibular branches ofthe facial nerve have been followed completely to the point of turningdeeply toward the facial musculature, the remaining portions of theparotid gland can be separated from the investing fascia (Figure 23–9)

♦ This separation completely mobilizes the superficial lobe of theparotid gland The so-called deep lobe of the parotid gland is the sali-vary tissue that remains undisturbed under the preserved facial nerve

• A superficial parotidectomy is adequate treatment for virtually all ficially located parotid masses; it allows the complete operative dissec-tion of first and second congenital branchial anomalies

super-• A total parotidectomy may prove necessary if the mass in question islocated within the deep lobe, or if the pathology involves the entiregland, as is the case in some vasoformative lesions and chronic inflam-matory processes

♦ In such circumstances, the main trunk and individual branches of thefacial nerve can be retracted gently with rubber vascular loops toallow access to the underlying parotid tissue (Figure 23–10)

Figure 23-8: Dissection along the facial nerve develops a plane of cleavage through the parotid gland (Adapted from Welch KJ, Randolph JC, editors Pediatric surgery Vol I Chicago: Year Book Medical Publishers; 1986 p 500.)

♦ The deep parotid tissue is separated from the underlying facial culature, temporomandibular joint, and mandible.

mus-♦ Ligation of the medially adjacent maxillary and superficial temporalarteries may be necessary Deep parotid lobe dissection exposes theparotid duct

• Neoplastic invasion of the facial nerve is extremely infrequent in atric parotid malignancies

pedi-♦ In the rare case of a resectable undifferentiated or sarcomatous nancy, total parotidectomy with facial nerve resection is performed inconjunction with a modified neck dissection and perhaps a partialmandibulectomy

malig-♦ The proximal aspect of the facial nerve typically is identified withinthe vertical segment of the fallopian canal; the peripheral facial nervebranches are likewise identified and tagged (Figure 23–11)

♦ Frozen section histopathology is used to determine healthy neuralmargins

♦ Immediate reconstruction by free autogenous nerve grafting is cated using either the sural nerve or the greater auricular nerve fromthe opposite side of the neck; the harvesting of the former allows atwo-team approach

advo-♦ Microanastomotic technique increases the likelihood of graft success

• When the facial nerve has been preserved in parotid surgery, the maintrunk, divisions, and individual branches of the nerve should be stimu-lated prior to wound closure to determine neural integrity If the facialmuscles do not twitch briskly with stimulation, the nerve must beinspected along its entire course for possible disruption A transectednerve should be repaired immediately Stretching or compression mayhave injured an anatomically intact nerve

• Following hemostasis and irrigation, suction drainage is recommended.The drain typically leaves the skin through a separate stab incision (Fig-ure 23–12)

♦ A Jackson-Pratt drain is appropriate in older children and adolescents.

♦ In infants and young children, a Brent butterfly drain using a large test

tube for vacuum purposes works well

• Closure is performed in two layers using interrupted absorbable suturessubcutaneously, and either nylon or absorbable sutures in an interrupt-

ed or running fashion in the skin

• A pressure dressing completes the procedure

Complications

• Facial paresis may be observed on the side of the operation for days oreven weeks postoperatively, depending on the extent of nerve mobiliza-tion If gentle retraction was performed and no significant branches ofthe facial nerve have been severed, complete recovery is the rule

• Gustatory sweating (Frey’s syndrome) occurs secondary to the regrowth ofparasympathetic motor fibers from the auriculotemporal nerve, which pre-operatively innervated the parotid gland, into the skin Efferent impulsesthat had induced salivation now stimulate the cutaneous sweat glands.

• Hypoesthesia of the earlobe is commonly present for up to severalmonths Permanent hypoesthesia can occur if the greater auricular nervehas been sacrificed

• Hemorrhage with secondary hematoma or seroma formation reflectsinadequate hemostasis or drainage

• Salivary fistula formation may occur if the parotid duct has not beenidentified and ligated prior to transection

SUBMANDIBULAR GLAND EXCISION

Submandibular gland neoplasms are extremely rare in children mative lesions, especially lymphatic vascular malformations, can arise with-

Vasofor-in the submandibular space The Vasofor-inflammatory processes that afflict theparaparotid lymph nodes can likewise involve the submandibular lymphnodes The submandibular gland itself is also susceptible to a higher rate ofstone formation (sialolithiasis) and secondary inflammation (sialoadenitis).Excision of the submandibular gland in children is infrequently necessary

Indications

• Chronic sialoadenitis with or without sialolithiasis

• A persistent firm submandibular mass of unknown or uncertain etiology

• Elective removal in an attempt to decrease salivary secretions in childrenwith excessive drooling secondary to cerebral palsy and other neuro-muscular disorders

Anesthetic Considerations and Preparation

• The procedure is performed under general anesthesia

• Paralytic agents are avoided to allow for intraoperative marginalmandibular nerve stimulation

• Informed consent regarding the risk of marginal mandibular nerveinjury is necessary

• The child is positioned supine with the head turned toward the volved side The operative field is draped with sterile transparent plasticsheeting to provide exposure of the corner of the mouth on the involvedside (Figure 23–13) This allows for the intraoperative assessment ofmarginal mandibular nerve function

unin-Procedure

• A horizontal skin incision is made in a neck crease two finger breadthsinferior and parallel to the angle and body of the mandible (Figure23–14)

• The incision is infiltrated with 1% lidocaine and 1:100,000 epinephrinesolution for hemostasis

• The skin, subcutaneous tissues, and platysma muscle are divided down

to the investing fascia of the submandibular gland The mylohyoid cle anteriorly, the sternocleidomastoid muscle posteriorly, and the digas-tric muscle inferiorly are exposed (Figure 23–15)

mus-• The fascia over the submandibular gland is divided at its inferior aspectand elevated toward the mandible The anterior facial vein is soughtbecause the marginal mandibular branch of the facial nerve usuallycrosses this vein; ligation and elevation of this vessel with the fascia helps

to shield the marginal mandibular nerve from injury (Figures 23–16A and B) Direct identification of the marginal mandibular nerve with the

use of a nerve stimulator is the best way to protect and preserve the nerveduring elevation of the fascia

• Mobilization of the submandibular gland is begun along its inferioraspect The plane between the intermediate tendon of the digastric mus-cle and the submandibular gland is opened (Figure 23–17)

♦ The hypoglossal nerve will be encountered deeply in the digastric angle

tri-♦ The external maxillary (facial) artery enters the posterior aspect of thesubmandibular gland; this vessel is double-ligated before transection

♦ Branches of the posterior facial (retromandibular) vein also requirecareful ligation

Figure 23–15 Exposure of the mylohyoid, sternocleidomastoid, and digastric muscles.

(Adapted from Montgomery WW Surgery of the upper respiratory system Vol II.

Philadelphia: Lea & Febiger; 1989 p 263.)

• Anterior retraction of the mylohyoid muscle and gentle downward tion on the submandibular gland allow identification of the lingualnerve, its attached submandibular ganglion, and the submandibular(Wharton’s) duct (Figure 23–18).

trac-♦ The duct is ligated and divided The efferent fibers arising from theganglion to the submandibular gland also are divided, freeing the lin-gual nerve from the gland

♦ The submandibular gland is now completely mobilized by blunt section The superior end of the external maxillary (facial) artery, ifnot previously ligated, should be identified and secured

dis-• After removal of the specimen, the submandibular space is exploredcarefully (Figure 23–19) The marginal mandibular nerve, if previouslyidentified, should be stimulated to determine neural integrity

• Following hemostasis and irrigation, a Penrose drain is placed throughthe operative incision (Figure 23–20)

• Closure is performed in two layers using interrupted absorbable suturesfor platysma muscle and subcutaneous tissue approximation, and eitherinterrupted or a single subcuticular nylon suture in the skin

• A pressure dressing completes the procedure

Complications

• Paresis or paralysis of the lower lip may occur secondary to injury to themarginal mandibular branch of the facial nerve If the anatomic integri-

ty of the nerve is operatively preserved, complete recovery is the rule

• Because the platysma muscle aids in depressing the lower lip, there may betransient unilateral lip weakness secondary to its intraoperative division

Figure 23–18 Complete

mobi-lization of the submandibular

gland.

RANULA EXCISION

Ranulas are cystic lesions of sublingual gland origin Simple ranulas are trueretention cysts appearing as transparent thin-walled cysts, typically unilat-eral, within the floor of the mouth The cervical or plunging ranula is amucous extravasation pseudocyst that arises as mucus escapes through aruptured sublingual duct Plunging ranulas may extend through the gapbetween the posterior edge of the mylohyoid muscle and the anterior edge

of the hyoglossus muscle into the superior cervical neck The presence of acystic floor-of-mouth swelling on the same side as a cystic swelling in thesubmental and/or submandibular space is suggestive of the diagnosis.Computed tomography or magnetic resonance imaging can distinguish aranula from a lymphatic vascular malformation, the clinical entity withwhich it is most commonly confused

Ranulas localized to the floor of the mouth are managed with intraoralmarsupialization or complete excision Plunging ranulas require completeexcision, typically via a transcervical approach

PLUNGING RANULA EXCISION Indications

• Plunging ranula associated with

♦ Dysphagia, speech impediment, or respiratory distress manifestations

♦ Recurrent infection

♦ Progressive enlargement

• Diagnostic confirmation of a cervical lesion

Anesthetic Considerations and Preparation

• The procedure is performed under general anesthesia

• Paralytic agents are avoided to allow for intraoperative marginalmandibular nerve stimulation

• Nasotracheal intubation is preferable to allow intraoral access if necessary

• Informed consent regarding the risk of marginal mandibular nerveinjury is necessary

Procedure

• The transcervical approach described for submandibular gland resection

is also used for surgical access to this lesion The submandibular ductpasses through the same muscle cleft through which the ranula typical-

ly extends The submandibular duct empties into the floor of the mouthmedial to the sublingual gland; it provides a direct pathway to the site ofranula origin (Figure 23–21)

• The anatomic proximity of these glandular structures often dictates theremoval of the submandibular gland with ligation of its duct to allowcomplete removal of the plunging ranula cyst The cervical approachprovides greater exposure and protection of the lingual nerve than is pos-sible transorally (Figure 23–22)

• Gloved intraoral palpation on the ipsilateral floor of the mouth can help

to deflect the sublingual gland into the operative field (Figure 23–23).Complete removal of the sublingual gland, ideally in continuity with theranula cyst, is necessary

• Cervical wound closure is performed as described above–see mandibular Gland Excision.

Sub-♦ If the floor-of-mouth mucosa has been disrupted, closure by rupted absorbable sutures is recommended

inter-♦ If the submandibular gland is not removed and the submandibularduct is transected, the proximal end of the duct must be brought outthrough the mucosa of the floor of the mouth for salivary drainage(Figure 23–24)

Complications

• The same postoperative sequelae described for submandibular glandexcision can occur following the transcervical excision of a ranula

• A ranula may recur if the sublingual gland is not operatively removed

• Submandibular sialoadenitis may occur if the submandibular gland isleft in place and the submandibular duct is injured intraoperatively

Figure 23–23 Gloved intraoral

palpation displaces the ranula

and attached sublingual gland

into the cervical operative field.

INTRAORAL RANULA EXCISION Indications

• Intraoral ranula associated with

♦ Dysphagia, speech impediment, or respiratory distress manifestations

♦ Recurrent infection

♦ Progressive enlargement

Anesthetic Considerations and Preparation

• The procedure is performed under general anesthesia

• Nasotracheal intubation is preferable to facilitate intraoral access

• The patient is positioned supine with the neck extended

Procedure

• A mouth retractor without a tongue blade is placed

• A silk suture placed in the midline of the tongue facilitates tongueretraction

• The orifice of the ipsilateral submandibular gland duct should be nulated with a Teflon catheter or metal lacrimal probe; this procedureidentifies the location of the submandibular duct so that it can be pro-tected from injury during dissection of the ranula cyst (Figure 23–25)

can-• A wide elliptical incision is outlined over the dome of the cyst (see ure 23–25)

Fig-• Lidocaine 1% with 1:100,000 epinephrine is infiltrated submucosallyfor hemostasis Care must be taken not to puncture the cyst

• If solely marsupialization or exteriorization of the ranula is planned, theentire dome of the cyst is removed, leaving an exposed bed to heal bysecondary intention; however, the rate of recurrence is high The moredefinitive procedure is complete excision of the ranula and the ipsilater-

al sublingual gland from which it arises

• When complete ranula excision is anticipated, no attempt is made to arate the overlying adherent mucosa from the underlying cyst: they areremoved together to facilitate ranula dissection ideally without disruption

sep-• Using primarily blunt and limited sharp dissection, the ranula cyst isseparated from the mucosal margins and deeper floor-of-mouth struc-tures (Figure 23–26)

♦ Care is taken not to injure the lingual nerve or the cannulated mandibular duct, both of which should be identifiable on the surface

sub-of the floor-sub-of-mouth musculature (Figure 23–27)

♦ The sublingual gland ideally is removed in continuity with the

• Postoperative edema of the floor of the mouth can potentiate airwayobstruction Intravenous dexamethasone during surgery may decreasethis risk Monitored postoperative observation is recommended;overnight nasotracheal intubation is a consideration in selected cases

• Postoperative hematoma of the floor of the mouth can likewise ate airway obstruction; this can be prevented by meticulous intraopera-tive hemostasis

potenti-• Ranula recurrence is a possibility if the sublingual gland is not removed

BIBLIOGRAPHY

Batsakis JG, Sneige N, El-Naggar AK Fine needle aspiration of salivary glands; its utility and tissueeffects Ann Otol Rhinol Laryngol 1992;101:185–8

Camacho AE, Goodman ML, Eavey RD Pathologic correlation of the unknown solid parotid mass

in children Otolaryngol Head Neck Surg 1989;101:566–71

Crysdale WS, Mendelsohn JD, Conley S Ranulas—mucoceles of the oral cavity: experience in 26children Laryngoscope 1988;98:296–8

Farrior JB, Santini H Facial nerve identification in children Otolaryngol Head Neck Surg1985;93:173–6

Loré JM Jr Excision of ranula In: Loré JM An atlas of head and neck surgery Philadelphia: WBSaunders; 1988 p 628–9

Loré JM Jr The parotid salivary glands In: Loré JM An atlas of head and neck surgery phia: WB Saunders; 1988 p 708–25

Philadel-Loré JM Jr Resection of the submandibular salivary gland for benign disease In: Philadel-Loré JM An atlas

of head and neck surgery Philadelphia: WB Saunders; 1988 p 678–81

Luna MA, Batsakis JG, El-Naggar AK Salivary gland tumors in children Ann Otol Rhinol gol 1991;100:869–71

Laryn-Matt BH, Crockett DM Plunging ranula in an infant Otolaryngol Head Neck Surg1988;99:330–3

May M, D’Angelo AJ Jr The facial nerve and the branchial cleft: surgical challenge Laryngoscope1988;99:564–5

Montgomery WW Surgery of the salivary glands In: Montgomery WW Surgery of the upper piratory system Vol II Philadelphia: Lea & Febiger; 1989 p 225–69

res-Seligman I, Lusk R Excision of a ranula in a child In Bailey BJ Surgery of the oral cavity go: Year Book Medical Publishers; 1989 p 209–14

Chica-Welch KJ The salivary glands In: Chica-Welch KJ, Randolph JC Pediatric surgery Chicago: Year BookMedical Publishers; 1986 p 487–502

T HYROIDECTOMY

Michael J Cunningham, MD

PREOPERATIVE EVALUATION

• Blood tests [serum thyroxine (T4), triiodothyronine (T3),

thyroid-stim-ulating hormone (TSH), antithyroglobulin antibodies, and somal antibodies] may be necessary for complete evaluation, but rarelyprove diagnostic for solitary thyroid masses The exception is an elevat-

antimicro-ed serum calcitonin level for mantimicro-edullary thyroid cancer

• Ultrasonography is useful in evaluating the size, position, and multiplicity

of thyroid lesions, as well as determining their cystic or solid character

• Thyroid scanning compliments ultrasonography, particularly in the

eval-uation of solid thyroid masses Thyroid malignancies frequently appear

“cold” on thyroid scanning; nonsuppressible “warm” and “hot” massescan also prove to be malignant

• Radiologic evaluation of children and adolescents with suspected thyroid

neoplasms should also assess the remainder of the neck and chest roid cancer in this age group often presents in an advanced stage withregional lymph node metastases and distant extrathyroidal disease, par-ticularly to the lungs Documenting regional or systemic metastases sig-nificantly influences initial surgical management, but does not necessar-ily imply a poor prognosis

Thy-Thyroidectomy is an infrequent procedure in children, performed most often for a tially malignant thyroid mass The differential diagnosis of a thyroid mass in a child or ado-lescent includes congenital anomalies (thyroglossal duct cyst, ectopic thyroid, unilateralthyroid lobe agenesis), thyroid abscess, colloid nodule, Hashimoto’s thyroiditis, benign ade-nomas, and malignant neoplasms Clinical factors suspicious for malignancy include largesize or rapid growth of the mass, fixation of the mass to surrounding structures, associatedvocal fold paralysis or ipsilateral cervical lymphadenopathy, bring exposure to radiationtherapy, or a familial predisposition to thyroid tumors

poten-• Fine-needle aspiration (FNA) biopsy with cytopathologic examination is

a valuable tool in the diagnostic work-up of thyroid masses, given thehigh specificity and ease and safety of this technique in experiencedhands Positive FNA results can help further select the appropriate thy-roid surgical procedure

• Open surgical biopsy is indicated for a solitary thyroid mass, which despite

extensive preoperative evaluation, cannot be definitively determined to bebenign or malignant A total thyroid lobectomy (hemithyroidectomy) isperformed initially, with more extensive surgery, if needed, dictated byintraoperative frozen section histopathologic tissue diagnosis

THYROIDECTOMY Indications

• A solitary thyroid mass, especially a solid mass for which a definitivebenign diagnosis cannot be made on the basis of preoperative evaluation

Anesthetic Considerations

• The procedure is performed under general anesthesia

• Paralytic agents are avoided to allow for intraoperative recurrent geal nerve (RLN) stimulation and monitoring

laryn-Preparation

• Preoperative evaluation of vocal fold function is mandatory From adiagnostic standpoint, documentation of impaired vocal fold mobility atpresentation is a clinical criterion suggestive of an underlying malignantetiology The presence of overt vocal fold paralysis may be important indictating the surgical course

• When there is normal vocal fold function, informed consent regardingthe risk of RLN injury is necessary

• Consideration should be given to intraoperative RLN monitoring

♦ In older children and adolescents, the Xomed NIM II EMG tracheal tube can be used for this purpose (Figure 24–1) This endo-tracheal tube has exposed electrodes which come in contact with theluminal surface of the true vocal folds, allowing passive and evokedelectromyogram (EMG) monitoring of the thyroarytenoid muscleduring thyroid surgery

endo-♦ Unfortunately, the smallest EMG endotracheal tube (outer diameter8.8 mm, inner diameter 6.0 mm) is too large for most children, but

is applicable in adolescents

♦ A surface electrode which monitors posterior cricoarytenoid muscleactivity can alternatively be used in younger children; this electroderequires placement against the posterior cricoid lamina by intraoper-ative laryngoscopy before the child is positioned for the definitivethyroid procedure (Figure 24–2)

• The child is placed in the thyroid position, supine with the neck in fullextension (Figure 24–3).

Procedure

• A transverse collar incision is outlined in the lower neck

1 The exact position of the incision must take into account the tionship between the palpable portions of the laryngeal skeleton, thesternum, and the thyroid gland

rela-2 The thyroid isthmus is situated immediately inferior to the cricoidcartilage A natural skin crease is chosen within 1-2 cm of this level(Figure 24–4)

3 In young children, the laryngeal structures may not be obviously pable, and may be considerably more cephalad relative to the sternalnotch than anticipated (Figure 24–5)

pal-• The planned incision is infiltrated with 1% lidocaine with 1:100,000epinephrine solution to provide hemostasis

Figure 24–3 Thyroidectomy operative position.

• The skin, subcutaneous tissues, and platysma muscle are transected Theanterior borders of the sternocleidomastoid muscle serve as the lateralmargins (Figure 24–6)

• The incision should be wide enough to allow adequate vertical exposure

A superior flap is elevated in the subplatysmal plane to the level of hyoidbone, and an inferior flap is elevated to the level of the sternal notch(Figure 24–7)

• The midline raphe between the strap muscles is incised, and the nohyoid and sternothyroid muscles are separated from one another andfrom the underlying thyroid gland (Figure 24–8)

ster-♦ Dividing the strap muscles is infrequently necessary in the pediatricpopulation

♦ When required for operative exposure, the muscles should be dividedhigh in the neck, above the cricoid cartilage to preserve ansa cervicalisinnervation

Figure 24–6 Transection of the

skin, subcutaneous tissues, and

platysma muscle (Adapted from

the Loré JM An atlas of head

and neck surgery 3 rd ed.

Philadelphia: WB Saunders;

1988 p.759.)

Identifying the recurrent laryngeal nerves

• Once the strap musculature is separated or divided, the mastoid muscle on the side of the lesion is retracted to identify thecarotid sheath structures (Figure 24–9)

sternocleido-• The thyroid lobe is retracted medially, and blunt dissection is fully performed in the superior thoracic inlet just caudal to the infe-rior thyroid pole to identify the recurrent laryngeal nerve (RLN)

care-• When searching for the RLN, it is preferable to identify the inferiorthyroid artery The nerve typically passes under this vessel, but may

be superficial (Figure 24–10)

• The right RLN normally recurs beneath the right subclavian artery;

the left RLN recurs beneath the aortic arch (Figure 24–11A) Both

recurrent nerves ascend toward the larynx in the tracheoesophagealgroove

♦ The left nerve ascends in a straight longitudinal direction parallel

to the lateral border of the trachea The right nerve follows a

short-er course, approaching the larynx at a right angle, coursing ally as it ascends Both nerves pass posterior to the thyroid lobes asthey approach the cricoid cartilage

medi-♦ A nonrecurrent right RLN can arise from the vagus nerve as adirect medial branch in the neck in approximately 0.5 to 1% of

individuals (Figure 24–11B) A nonrecurrent left RLN is rare,

typ-ically occurring only with transposition of the great vessels

Figure 24–9 Retraction of the

sternocleidomastoid muscle for

carotid sheath exposure.

Thyroid mobilization

• Once the RLN is identified inferiorly, dissection proceeds cephalad Theinferior and middle thyroid veins on the side of the lesion will need to

be ligated and divided for adequate gland mobilization (Figure 24–12)

• Ligating the main trunk of the inferior thyroid artery should beavoided to preserve the blood supply to the parathyroid glands; small-

er medial branches of this artery may be ligated close to the capsule

2 If the plane of the superior pole dissection continues bluntly alongthe presenting portion of the cricothyroid muscle, the likelihood

of superior laryngeal nerve (SLN) injury is small

3 Ligation without clamping of the superior pole vessels furtherdecreases the likelihood of SLN injury

Figure 24–12 Ligation and

divi-sion of the inferior and middle

thyroid veins (Adapted from

Silver CE Atlas of head and

neck surgery New York:

Churchill Livingstone; 1986

p 265.)

• Following transection of the superior vascular pedicle, the superiorpole of the thyroid lobe is reflected inferiorly The thyroid lobe nowremains firmly attached by the lateral or posterior (Berry’s) suspenso-

ry ligament (Figure 24–14), which extends bilaterally from thecricoid cartilage and first tracheal ring to the posteromedial aspect ofeach thyroid lobe

1 The suspensory ligament is an extremely important structurebecause the RLN typically passes immediately deep (see Figure24–14) Variations, however, exist and must be anticipated

2 Once the RLN has been clearly identified, the suspensory ligament

is transected A portion of thyroid tissue may also extend deep tothis ligament and must be carefully removed

3 After transecting the ligament, the remaining thyroid separateseasily from the surface of the trachea

Thyroid Excision

• Dissection proceeds medially until the entire isthmus has been vated The isthmus is transected at its junction with the contralaterallobe (Figure 24–15)

ele-• This completes a total thyroid lobectomy (hemithyroidectomy)

• If the indication for surgical intervention is a thyroid mass ofunknown etiology, or if confirmation of needle biopsy findings issought, a frozen section histopathologic examination of the hemithy-roidectomy specimen is performed

♦ Histopathologic findings may dictate the further performance of atotal or near-total (subtotal) thyroidectomy

♦ If the diagnosis of thyroid carcinoma (typically papillary or lary-follicular) is histopathologically established, the decisionneeds to be made as to whether to consider the hemithyroidecto-

papil-my as the definitive procedure, taking a chance of recurrence in thecontralateral lobe, or to immediately perform a total or subtotalthyroidectomy

♦ These procedures necessitate life-long thyroid hormone ment, but allow for postoperative radionuclide scanning for futuredetection of both local recurrence and metastases, and enhance theefficacy of 131I therapy if needed

replace-• When removing the contralateral lobe, the identical technique, viously described for the ipsilateral lobe with exposure of the RLN, isused Identifying and preserving parathyroid tissue is crucial.

pre-1 Performing a subtotal thyroidectomy lessens the risk of permanenthypoparathyroidism

2 With this technique, a small portion of the contralateral thyroidlobe is left in situ with its adjacent parathyroid gland(s)

3 The inferior thyroid artery is also not ligated in order to preservethe blood supply to these glands (Figure 24–16)

• Subtotal thyroidectomy is controversial, because of the possiblefuture need, if disease recurs, to remove the small wedge of remainingthyroid tissue There is a much greater risk to the RLN and residualparathyroid glands under such circumstances There also appears to

be little correlation between thyroid function and the amount ofresidual thyroid tissue These problems have led many surgeons toconsider the procedure of choice to be total thyroidectomy with iden-tification and, if need be, re-implantation of the parathyroid glands

• When there is advanced thyroid cancer, as evidenced by infiltration

of surrounding tissues or cervical and systemic metastases, total roidectomy with paratracheal lymph node removal is advocated Theaccompanying performance of a more formal modified neck dissec-tion depends on the specific thyroid malignancy

thy-Wound Closure

• Following hemithyroidectomy, subtotal, or total thyroidectomy, theoperative site is carefully re-inspected for the presence of parathyroidglands and the integrity of both the RLN and SLN

• If intraoperative RLN monitoring has been utilized, positive cal stimulation of RLN function confirms visual documentation of itsintegrity

electri-• Following hemostasis and irrigation, a Penrose drain is placed and thestrap muscles are loosely approximated in the midline

• Closure is performed in two layers, using interrupted absorbablesutures to approximate platysma muscle and subcutaneous tissues,and either interrupted or a single subcuticular nylon suture for theskin (Figure 24–17)

• A compression dressing is applied to complete the procedure

Postoperative Care

• Injury to either the RLN or the external branch of the SLN may occur

♦ RLN injury typically results in an immobile vocal fold in a midline

or paramedian position, and may predispose to aspiration or airwayobstruction

♦ SLN injury results in a bowed vocal fold

♦ Both neural injuries adversely affect the voice