OPEN ACCESS ATLAS OF OTOLARYNGOLOGY, HEAD & OPERATIVE SURGERY

TRANSORAL LATERAL OROPHARYNGECTOMY / RADICAL FOR CANCER OF THE TONSIL: , PRINCIPLES AND TECHNIQUES Johan Fagan & Wayne Koch

In developed countries, early (T1/2) tonsil Surgical anatomy cancers are commonly resected by lateral oropharyngectomy (radical tonsillectomy) The oropharynx encompasses the base of employing transoral CO2 laser microsurge- , tonsils, soft palate, and lateral and ry or transoral robotic surgery (TORS) posterior walls of the between the techniques. Yet most surgeons in the world levels of the hard palate and hyoid bone do not have access to CO2 laser or TORS. (Figures 1a, b). In such centers early tonsil cancers are often resected by simple tonsillectomy. However, dissecting along the tonsillar capsule and not including the pharyngeal constrictors as the deep margin often results in close or involved deep margins necessitating adju- vant (chemo)radiation.

Because cancers of the tonsil are in a direct line-of-sight for the surgeon when using a simple tonsillectomy gag, there is little reason why the surgical principles that apply to lateral oropharyngectomy by trans- oral CO2 laser or TORS techniques should not be employed to lateral oropharyngec- tomy performed with headlight/diathermy, or microscope/diathermy, or loupes/head- Figure 1a: Oropharynx light/diathermy techniques to secure ade- quate resection margins.

Regardless of the surgical tools being used, lateral oropharyngectomy requires a detail- ed understanding of the “inside-out” 3D anatomy of the oropharynx, and of the para- pharyngeal (PPS) and retropharyngeal spa- ces. Without such an understanding one is less likely to achieve adequate resection margins and more likely to encounter bleeding, nerve damage and injury to the internal carotid artery.

This chapter details the surgical anatomy of the oropharynx, PPS and retropharyngeal Figure 1b: Oropharynx spaces, and discusses principles and techni- ques relating to transoral resection of tonsil Key anatomical structures relevant to lateral cancers regardless of the surgical tools oropharyngectomy are listed in Table 1 and being used. illustrated in Figure 2. 1

2

Ligaments sillolingual sulci separate the tongue from and fasciae Buccopharyngeal the tonsillar fossae. The valleculae separate Muscles Buccinator the BOT from the lingual surface of the Superior constrictor Middle constrictor epiglottis and are separated in the midline Medial pterygoid by the median glossoepiglottic fold (Figure Stylopharyngeus 3). Muscles of soft palate Nerves Lingual Epiglottis Glossopharyngeal (IX) Valleculae Arteries Internal carotid Median glosso- Dorsalis linguae epiglottic fold Ascending pharyngeal Tonsil Tonsillar and ascending palatine Tonsillolingual branches of facial artery sulcus Descending palatine Foramen caecum Spaces Prestyloid PPS Sulcus terminalis Poststyloid PPS Table 1: Key anatomy for lateral oro- pharyngectomy

Buccinator

Pterygomandibular raphe Figure 3: Topography of BOT Palatoglossus

Medial pterygoid fascia Soft palate Superior constrictor

Buccopharyngeal fascia The soft palate has a complex muscular External carotid structure and innervation. It has key func- Styloglossus & Stylopharyngeus tions relating to speech and swallowing.

Palatopharyngeus Resection and inadequate reconstruction of

Internal carotid the palate results in loss of nasal separation

Internal jugular vein which manifests clinically as nasal regurgi- tation of fluids and food, and hypernasal Figure 2: Key anatomical structures for speech which can be quite disabling. The lateral oropharyngectomy at level of tonsil; complex muscular anatomy of the soft yellow tissue is parapharyngeal fat palate and lateral pharyngeal wall is illu- (Adapted from Ento Key) strated in Figure 4. Muscles that contribute to the soft palate and lateral pharyngeal wall Base of tongue (BOT) are summarised in Table 2.

This comprises the posterior 1/3 of the Lateral and posterior pharyngeal walls tongue behind the foramen caecum and sulcus terminalis (Figure 3). The mucosa is Lateral oropharyngectomy involves dissec- rough, thick and fixed to the underlying ting along the outer aspect of the pharyngeal muscle and contains lymphoid follicles constrictors. The oropharynx has several (lingual tonsil); this makes it difficult to layers i.e. mucosa, , muscle and identify the edges of a BOT tumour; hence . The submucosa is frozen section is especially useful to assess represented by the resection margins. Posterolaterally the ton- that lines the inner aspect of the constrictor 3

muscles. It thins as it extends inferiorly

Levator veli palatini from its attachment to the skull base and Tensor veli palatini bridges the gaps between the skull base and Styloid the superior constrictor, the superior and Stylopharyngeus middle constrictors, and the middle and inferior constrictors (Figure 5). Posteriorly Palatopharyngeus it forms a median raphe to which the Salpingopharyngeus pharyngeal constrictors attach (Figure 5). Musculus uvulae Superior constrictor The buccopharyngeal fascia invests the pharyngeal constrictor muscles and is Figure 4: Posterior view of soft palate and continued forward from the superior pharynx with superior constrictor splayed constrictor over the buccinator (Figure 2). open It is loosely attached to the prevertebral layer by connective tissue, with the retro- pharyngeal space between them. Tensor veli palatini V3 Levator veli palatini X Soft palate Palatoglossus X The pterygomandibular raphé/ is Palatopharyngeus X a tendinous band of buccopharyngeal fas- Musculus uvulae X cia and is a key structure to identify initially Salpingopharyngeus X in lateral oropharyngectomy to gain access Lateral Superior constrictor X to the correct lateral dissection plane. It is pharyngeal wall Middle constrictor X Stylopharyngeus IX attached at one end to the hamulus of the medial pterygoid plate, and at the other end Table 2: Muscles of soft palate and to the posterior end of the of oropharynx and cranial nerves which the (Figures 6, 7). innervate them

PBF

Superior constrictor

Stylopharyngeus

Median raphe

Middle constrictor

Inferior constrictor Figure 5: Posterior view of pharynx illu- strates attachment of the superior con- strictor to pharyngobasilar fascia (PBF) above and the median raphe to which Figure 6: Note how buccinator and supe- pharyngeal constrictors attach; note close rior constrictor muscles attach to the pte- anatomical relationships of internal and rygomandibular raphe (yellow line) external carotid artery systems to pharynx 4

It is interposed between the buccinator mus- cle which is attached to its anterior edge, and the superior constrictor muscle which is attached to its posterior edge (Figures 2, 6). Medially it is covered only by buccal mucosa. Laterally it is separated from the MT ramus of the mandible and medial pterygoid muscle and fascia by (Figure LN 2). The pterygomandibular fold represents the surface marking of the pterygomandi- bular raphe (Figure 7).

Figure 8: The lingual nerve (LN) courses lateral to the medial pterygoid muscle (MT)

Pterygomandibular raphe (cut superiorly)

Nerve to mylohyoid

Submandibular ganglion

Lingual nerve

Hyoglossus Figure 7: Pterygomandibular fold repre- Figure 9: Lingual nerve emerging between sents the surface marking of pterygoman- lower attachment of raphe to the mandible dibular raphe and the (adapted from Earthslab.com) The lingual nerve emerges anteriorly be- tween the medial pterygoid and the vertical Medially, it is covered by submucosa and ramus of the mandible (Figure 8). It is mucosa of the . Laterally it is related therefore protected by the medial pterygoid to the ramus of the mandible, the masseter muscle during lateral oropharyngectomy. and medial pterygoid muscles, the buccal However, it is vulnerable to injury when fat pad and the buccopharyngeal fascia. dissecting inferiorly where it courses above the mylohyoid muscle (Figure 9). The superior and middle constrictor mus- cles form the lateral and posterior walls of The is transected during the oropharynx (Figures 4, 5, 6, 9, 10), with lateral oropharyngectomy just anterior to lesser contributions from the salpingo- the pterygomandibular raphe. It is a thin, pharyngeus (Figure 4), stylopharyngeus quadrilateral muscle in the cheek, and origi- (Figures 4, 5, 6, 10) and palatopharyngeus nates from the outer surfaces of the alveolar (Figure 4) muscles. processes of the maxilla and mandible. Posteriorly it attaches along the length of The stylopharyngeus arises from the medial the pterygomandibular raphe (Figures 2, 6). side of the base of the styloid process, pass- es downward through the fat of the PPS 5

along the side of the pharynx, then between dissection. It has two heads: the larger deep the superior and middle constrictors, and head arises from just above the medial fans out beneath the mucosa (Figures 2, 5, surface of the lateral pterygoid plate; the 6, 10). The glossopharyngeal (IX) nerve in- smaller superficial head arises from the nervates the stylopharyngeus. It runs on the maxillary tuberosity and the pyramidal lateral side of the muscle and crosses over it process of the palatine bone (Figure 11). to reach the base of the tongue (Figure 10). The muscle passes inferolaterally to insert onto the inferomedial surface of the ramus The deep dissection plane during lateral and angle of the mandible. oropharyngectomy is between the bucco- pharyngeal fascia/fat of the prestyloid, retrostyloid and retropharyngeal spaces, and the constrictors. Because the stylo- pharyngeus crosses the PPS to join the pharynx, it must be transected to enable the surgeon to follow the plane along the con- strictors towards the retropharynx (Figures 2, 10).

Figure 11: Medial and lateral pterygoids

Parapharyngeal space (PPS)

The pharyngeal constrictor muscles form the medial border of the PPS, and the dis- section therefore proceeds alongside, or within the fat of the PPS (Figures 12, 13). Therefore, the surgeon must be familiar with the anatomy of the PPS to anticipate the location of blood vessels, the stylopha- Figure 10: Relationships of stylopharyn- ryngeus muscle and the ICA. geus muscle (green) and internal carotid artery and internal jugular vein. Yellow Pharyngobasilar fascia arrow points to IX nerve. Yellow broken line Superior constrictor indicates division of stylopharyngeus mus- Tensor Veli Palatini cle during lateral oropharyngectomy muscle & fascia (adapted from Netter’s Anatomy) Medial Pterygoid The muscles of the soft palate are not indi- Mandible vidually dissected and identified but are Internal Carotid simply transected with the primary tumour. Internal Jugular Parotid gland Styloid process The medial pterygoid (Figures 2, 8, 11, 12) constitutes the anterolateral border of the Figure 12: Axial view of prestyloid (yel- prestyloid PPS and is exposed early in the low) and poststyloid (pink) PPS 6

The PPS extends as an inverted pyramid from the base of the skull superiorly, to the hyoid bone inferiorly. Figures 2 and 12 Dorsal illustrate axial views of the prestyloid and lingual poststyloid components of the PPS, separa- artery ted by the styloid process, tensor veli pala- tini muscle and its fascia (brown). The Lingual prestyloid PPS is bordered anterolaterally artery by the medial pterygoid muscle, and poste- rolaterally by the deep lobe of the parotid Facial artery gland (Figures 2, 12) and contains mainly fat. It is traversed by the arteries and veins supplying the pharynx and tonsil. The post- styloid PPS is confined medially by the pharyngobasilar fascia above, and the supe- Ascending pharyngeal rior and middle constrictor muscles of the artery pharynx and contains the internal carotid artery and the internal jugular vein, as well Ascending as lower cranial nerves IX -XII, and the palatine branch sympathetic trunk. of facial artery XII IX Arteries and veins (Figures 13, 14) Tonsillar branch of facial artery

Knowledge of the vascular anatomy ena- Descending palatine artery bles the surgeon to anticipate where arte- ries will be encountered and to minimise Figure 13: Arterial supply of tonsil and blood loss. Depending on the surgical pro- lateral oropharyngeal wall cedure, vessels that may be encountered include the tonsillar and ascending pala- tine branches of the facial artery that arise in Level 1 of the neck, and the ascending pharyngeal artery, a branch of the external carotid artery (Figure 13). If the dissection includes BOT, the dorsalis linguae bran- ches of the may be encoun- tered (Figures 13, 14). If the dissection is extended superiorly, the descending pala- tine artery may be encountered at the junc- tion of the soft and hard palates (Figure 13).

Venous drainage is via the pharyngeal venous plexus to the internal jugular vein (Figure 5). The internal jugular vein is located posterolateral to the carotid and is Figure 14: The ascending pharyngeal and hence not a concern (Figures 2, 5, 10). ascending palatine and tonsillar branches

of the facial (external maxillary) artery lie

on the pharyngeal constrictor in the PPS 7

The internal carotid artery is generally not Somatic sensory Tonsils, base of tongue, pha- exposed, although pulsations of the vessel rynx, middle ear through the surrounding fat should be Visceral sensory Carotid bodies Carotid sinus looked out for. Dividing the stylopharyn- Parasympathetic Parotid gland via otic gang- geus muscle gives direct access to the fibres lion poststyloid PPS and artery (Figures 2, 5, 10, Motor fibres 14). The artery is normally located about Table 3: IXn functions 20-30mm posterolateral to the outer aspect of the constrictors but may be ectatic (Fig- Lateral Oropharyngectomy ure 15) in up to 40% of the cases. A retro- pharyngeal ICA must be recognised preope- Lateral oropharyngectomy for cancer of the ratively and protected and may be a relative tonsil and lateral pharyngeal wall may be contraindication to transoral resection. performed with a headlight and monopolar

electrocautery, operating microscope and electrocautery, transoral CO2 laser micro- surgery or TORS. The latter two techniques provide superior visual detail of tissue pla- nes, tumour margins, vasculature and nerves. The description of the surgical steps that follow apply equally to all these techni- ques.

Indications

• Tumours of the lateral pharyngeal wall and tonsil that can be resected trans- orally with clear margins • The ideal tumour is a T1/2 tonsil cancer in which the constrictor muscles have Figure 15: Retropharyngeal internal caro- not been invaded tid artery 1 Contraindications Glossopharyngeal nerve (IXn) General Figures 10 and 13 show the course of the • Poor transoral surgical access XIn in the PPS. The main trunk of the nerve • Coagulopathy curves anteromedially around the lateral • Cervical spine pathology border of stylopharyngeus and courses • Poor fitness for surgery between the superior and medial pharyngeal constrictors. Of the functions of the IXn Oncologic listed in Table 3, injury to the nerve during • Cancer invading beyond pharyngeal lateral oropharyngectomy would only affect constrictors to involve tissues and struc- taste and sensation to the base of tongue. tures in PPS, medial pterygoid muscle, mandible or maxilla (requires combined transoral and transcervical approaches) • Clinical evidence of perineural exten- sion along major nerves e.g. lingual / V3 8

• Posterolateral fixation of cancer to pre- vertebral fascia • Substantial extension into tongue base beyond unaided transoral exposed view

Vascular • Retropharyngeal carotid artery • Cancer adjacent to ICA or carotid bulb Figure 16: Mallampati scoring system which will result in exposure of vessel • Tumour encasement of carotid artery Radiological evaluation

Functional • Primary tumour • Resection of >50% deep tongue base o CT / MRI / US2 (Figures 17ab) • Resection of >50% of posterior pharyn- o Not always required geal wall o Mainly for advanced tumours if • Resection of up to 50% of tongue base concern about extension to PPS and as well as entire epiglottis adjacent structures • Resection of soft palate causing debili- o To determine position of internal tating velopharyngeal insufficiency carotid artery with larger resections • Neck Clinical evaluation • Chest

• Location and extent of primary tumour determined by visual inspection, palpa- tion (and ultrasound2 evaluation) • Mobility of tumour with swallowing and on palpation: if mobile it suggests that the PPS is not involved • Fixation to prevertebral fascia: assessed T MT by gently rocking soft tissue of tonsil fossa medially and laterally using bi- manual palpation with one finger intra- orally and opposite hand extraorally

• Function of lingual, inferior alveolar, mental, and hypoglossal nerves • Position of ICA (inspection and palpa- tion) • Cervical and distant metastasis • Synchronous primaries • Access T o opening o Trismus (possible medial pterygoid and infratemporal involvement) o Dentition Figures 17ab: Axial and coronal CTs illu- o Cervical spine extension strate PPS fat (yellow arrows) separating o Mallampati score (Figure 16) tumour (T) from medial pterygoid muscle (MT), and the position of internal carotid artery (red arrow) 9

Informed consent • Liga clip applicator and clips, as used for transoral laryngeal microsurgery • Trauma (Figure 20) o Dental o Lips, soft tissue o Traction injury of lingual and hypo- glossal nerves due to prolonged ton- gue depression • Failure to complete transoral resection • Possible conversion to combined trans- cervical approach • Flaps o Oropharynx defect o Cervical communication • • Tracheostomy • Postoperative o Feeding

o Analgesia Figure 18: Dingman retractor o Primary or secondary haemorrhage o Healing time • Anticipated functional outcomes Figure 19: Long-tipped insulated blade Anaesthesia extension for monopolar cautery

• General anaesthesia • Orotracheal or nasotracheal intubation • Nasogastric feeding tube contralateral to tumour (not always) • Perioperative if combined neck dissection

Surgical instrumentation (minimum) Figure 20: Liga clip applicator The minimum instruments required for transoral lateral oropharyngectomy using a Surgical steps headlight +/- loupes include the following: • Tonsillectomy instrument set • Perform panendoscopy to exclude syn- • Tonsil / Dingman retractor (Figure 18) chronous tumours • Lindholm or other broad laryngoscope • Inspect and palpate the tumour to for reaching inferior extension, lateral determine mobility and extent wall or tongue base • Palpate tumour to ascertain extension to • Standard or extended length monopolar tongue base, fullness to superolateral electrocautery with insulated blade (for aspect of pterygomandibular fold, soft blunt dissection in PPS) (Figure 19) palate, mobility with respect to pterygo- • Bipolar long-tipped insulated electro- mandibular ligament cautery 10

• Insert Dingman or tonsil retractor and • Identify the fascia overlying medial place in suspension pterygoid muscle (Figure 23) • Identify the pterygomandibular fold; it Buccinator can be located by palpation (Figure 21) Pterygomandibular raphe

Palatoglossus

Medial pterygoid fascia

Superior constrictor

Buccopharyngeal fascia

External carotid

Styloglossus & Stylopharyngeus

Palatopharyngeus

Internal carotid

Internal jugular vein

Figure 21: Pterygomandibular fold repre- sents the surface marking of pterygoman- dibular raphe

• Incise the oral mucosa over the ptery- gomandibular fold to expose the ptery- gomandibular raphe; it is a key anato- mical landmark to establish the correct lateral dissection plane (Figure 22)

2 Figure 23: Key anatomical structures for lateral oropharyngectomy and typical dis- 1 section lines and planes for lateral oro- pharyngectomy (Adapted from Ento Key)

3 • Dissect posteriorly along the medial pterygoid fascia while retracting the tumour and tonsil medially 4 • If possible, preserve the buccopharyn- geal fascia to seal the oropharynx from structures in the PPS Figure 22: Typical sequence of incisions • Free the superior pole of the specimen by incising through the pterygomandi- • Transect the buccinator muscle along its bular raphe, and soft palate mucosa and attachment to the pterygomandibular muscles (Figure 22) raphe (Figures 22, 23) 11

• Free the tumour posteriorly by exten- • Release the specimen with final infe- ding this incision inferiorly through the rior cuts at the tonsillolingual sulcus and palatopharyngeus muscle (posterior medial cuts through the superior pha- tonsillar pillar) and pharyngeal mucosa ryngeal constrictor (Figures 24 a,b) and superior pharyngeal constrictor; this prevents the surgeon excising the posterolateral pharyngeal wall too far medially during the final steps of re- section (Figures 20, 21) • Free the tumour inferiorly by cutting below the tumour, including the tonsil- lolingual sulcus and lingual tonsil if required (Figures 22, 23) • Continue the lateral dissection, taking care to remain medially in the dissect- tion plane on the superior pharyngeal constrictor, palatoglossus, and palato- pharyngeus muscles, using blunt dis- section with the blade of the cautery • Multiple branches of the facial, lingual and ascending pharyngeal arteries are seen to enter the specimen and are clipped, cauterised or tied and divided • The facial or lingual arteries may have to be clipped or tied • Identify the oblique-running styloglos- sus and vertically running stylopharyn- geus muscles inferiorly in the surgical field • The IX nerve may be seen coursing an- terolaterally between these muscles (Figures 10, 13) • The styloglossus and stylopharyngeus muscles obscure the internal carotid artery from the surgeon superiorly in the

field (Figure 10). Transmitted pulsa- tions, also from the external carotid Figures 24 a,b: Typical resection (yellow) artery, can be observed through the muscles, parapharyngeal fat and bucco- • Carefully orientate and mark the speci- pharyngeal fascia men for the pathologist before remov- • Dissect bluntly when freeing the stylo- ing it from the mouth glossus and stylopharyngeus muscles • If concern remains about inferior exten- inferiorly to avoid injury to the lingual sion to lateral wall or tongue base, re- artery move mouth retractor and examine with • Transect the styloglossus and stylo- wide laryngoscope. Limited resection of pharyngeus muscles inferiorly as they residual disease may be undertaken with course between the superior and mid- cup forceps and extended monopolar dle pharyngeal constrictors cautery using telescope for improved 12

visualisation and evacuating suction for • Taste disturbance due to prolonged trac- smoke tion or surgical injury to the lingual • Obtain haemostasis nerve…recovers with time • If there has been a concurrent neck • Hypoglossal nerve traction injury… dissection, check for a direct communi- recovers with time cation with the neck Other issues Postoperative care Can the specimen be removed piecemeal? • Analgesia • Feeding: Commence when comfortable • It is a well-established, safe practice • Airway with transoral CO2 laser microsurgery • Bleeding to transect tumour to determine depth of • Antibiotics only if concomitant neck invasion and to remove a tumour piece- dissection meal, or to debulk the tumour to facili- tate resection Complications • When a large oropharyngeal tumour prevents adequate exposure of the mar- • Postoperative haemorrhage (1.5 - 13% gins, it is therefore acceptable to tran- of TORS) sect the tumour and remove it piece- o Up to a month postoperatively meal, taking care to accurately orientate o Potentially life-threatening the specimens for the pathologist o Multiple large vessels are ligated and are left exposed to the pharynx What constitutes a clear margin? to scar over by secondary intention o With large resections one may elect • It is not possible to achieve wide deep to ligate the facial and lingual arte- margins with cancers of the lateral ries or the ECA during the neck pharyngeal wall without having to re- dissection to reduce the severity of sect the contents of the PPS postoperative bleeding • However, a 99% 5-year estimated local o Management depends on severity control was reported by Hinni (2013) ▪ Minor: Observe in hospital following transoral resection of 128 ton- ▪ Major sil cancers with average deep resection • Intubate/ tracheostomy margins of only 1.98mm 3 • Ligate/clip bleeders • Therefore, favourable outcomes can be • Ligate ECA achieved provided microscopically • Embolisation clear margins are achieved • Airway obstruction o Bleeding When is reconstruction required? o Oedema o Flaps • An exposed carotid artery must be cov- o Secretions ered with a flap (note: full thickness re- o If in doubt, do a tracheostomy or moval of the pharyngeal constrictor keep intubated muscle with extension into PPS fat is an • Dental trauma indication for a combined open and • Lip or tongue lacerations transoral approach. This approach also provides access for flap inset, and is a 13

natural extension of neck dissection, management of ECA) • Significant resection of soft palate can cause palatal incompetence that mani- fests as nasopharyngeal reflux and im- paired speech • Function does improve as the tumour bed scars and contracts with time • It remains a judgement call when recon- struction of the palate is required to prevent these sequelae • Options include o Local palatal flaps e.g. rotating uvula into the defect Figure 26: Soft palate and tonsil fossa o Buccal fat pad flap (Figure 25) defect reconstructed with buccinator flap o Buccinator myomucosal flap (Figu-

re 26) o Radial free forearm flap (Figure 27) o Supraclavicular flap (Figure 28) o Submental artery island flap (Figure 29) o Pectoralis major flap o Anterolateral free thigh flap

Figure 27: Radial free forearm flap recon- struction of oropharynx and soft palate defect

Figure 25: Buccal fat pad flap used to aug- ment the palate or to close a pharyngo- cervical communication

Figure 28: Supraclavicular flap 14

• Submental artery island flap (Figure 29) • Pectoralis major flap • Anterolateral free thigh flap

Feeding tube

It is simpler to remove a nasogastric feeding tube the day following surgery, than to have to insert it should the patient struggle to swallow

Figure 29: Submental artery island flap Tracheostomy

Neck dissection Tracheostomy may be considered for two reasons i.e. concerns about the airway • Oropharyngeal squamous carcinomas (oedema, soft tissue reconstruction, patient generally need to have the N0 neck factors) or when there are concerns about treated either surgically or with (chemo) postoperative bleeding. It remains a judge- radiation ment call by the surgeon in consultation • Neck dissection is ideally done at the with the anaesthetist. same operation, but may be staged • There is a risk of causing a communi- Salvage surgery cation between the pharynx and sub- mandibular triangle at the tonsillolin- Salvage surgery may be considered follow- gual sulcus ing previous transoral resection and/or • A communication can be avoided by chemoradiation. It requires a higher level of o Cutting through the submandibular surgical skill and experience, and a very gland with cautery, leaving the deep detailed radiological assessment of resecta- portion of the gland in situ bility via a transoral approach. When con- o Leaving the whole submandibular cerns exist about injuring the ICA, the ICA gland in situ, taking care to clear the may first be exposed via Level 2 of the neck facial nodes (there are no intra- and gauze packed anterior to the ICA in the glandular lymph nodes) PPS to protect it during the transoral phase • Should a communication occur, then it of the dissection. can be dealt with by o Suturing the free margin of the References mylohyoid to the posterior belly of digastric and avoiding placing the 1. Weinstein GS, O’Malley BW, Rinaldo tip of the suction drain close to A et al. Eur Arch Otorhinolaryngol Level 1 2015; 272 (7): 1551-2 o Repairing the defect with a flap https://doi.org/10.1007/s00405-014- • Buccal fat pad flap (Figure 25) 3331-9 • Buccinator myomucosal flap 2. Faraji F, Coquia SF, Wenderoth MB, (Figure 26) Padilla ES, Blitz D, DeJong MR, Aygun N, Hamper UM, Fakhry C. Evaluating • Radial free forearm flap (Figure oropharyngeal carcinoma with trans- 27) • Supraclavicular flap (Figure 28) 15

cervical ultrasound, CT, and MRI. Oral THE OPEN ACCESS ATLAS OF Oncology. 2018: 78:177-85 OTOLARYNGOLOGY, HEAD & 3. Hinni ML, Zarka MA, Hoxworth JM. Margin mapping in transoral surgery for NECK OPERATIVE SURGERY www.entdev.uct.ac.za . Laryngoscope. 2013 May;123(5):1190-8

Additional reading The Open Access Atlas of Otolaryngology, Head & Neck Operative Surgery by Johan Fagan (Editor) • Chapter in Open Access Atlas of Otolar- [email protected] is licensed under a Creative yngology Head and Neck Operative Commons Attribution - Non-Commercial 3.0 Unported Surgery: resec- License

tion • Gun R, Durmus K, Kucur C, et al. Transoral Surgical Anatomy and Clini- cal Considerations of Lateral Orophar- yngeal Wall, , and Tongue Base. Otolaryngol Head Neck Surg. 2016 Mar;154(3):480-5

Author

Wayne M. Koch, MD Professor of Otolaryngology-Head & Neck Surgery Johns Hopkins University Baltimore, MD 21287 USA [email protected]

Author & Editor

Johan Fagan MBChB, FCS (ORL), MMed Professor and Chairman Division of Otolaryngology University of Cape Town Cape Town, South Africa [email protected]