Chapter 46: Pharyngeal And Esophageal Reconstruction

The nasopharynx is a narrow space posterior to the nasal cavity and above the soft palate (Fig. 46.1). It is located immediately below the central skull base and has the following boundaries: ● Superior: Sphenoid sinus and upper skull base (clivus) ● Inferior: Soft palate ● Anterior: Choanae ● Posterior: Lower skull base (clivus) and first cervical vertebra The retropharyngeal space is located at the level of the hypopharynx, which forms its posterior boundary.1–4 Fig. 46.1 Subdivisions of the pharynx. Oropharynx Hypopharynx Cervical esophagus Thyroid cartilage Posterior lamina of cricoid cartilage Anterior arch of cricoid cartilage

The oropharynx extends from the junction of the hard and soft palates to the aryepiglottic folds, with the hyoid and valleculae representing the inferior boundary. The base of tongue and the circumvallate papillae represent the ventral boundary, whereas the dorsal pharyngeal wall is the dorsal boundary. The lateral boundary is formed by the tonsillar fossa (see Fig. 46.1).1–4

The bilateral piriform sinuses represent subsites of the hypopharynx. The other subsites of the hypopharynx are the postcricoid area and the posterior hypopharyngeal wall. The soft palate, tonsils, tongue base, and oropharyngeal walls are subsites of the oropharynx.1–3

4. Schecter GL, Wadsworth TT. Hypopharyngeal cancer. In: Bailey BJ, ed. Head & Neck Surgery: Otolaryngology. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 1998

A patient may present with referred otalgia in the presence of a pharyngeal tumor. This occurs because sensory fibers from the pharyngeal plexus synapse in the jugular ganglion with Arnold’s nerve, which supplies the external auditory meatus. Arnold’s nerve is primarily formed from the vagus, with contributions from the facial and glossopharyngeal nerves. Such patients generally require a full workup including nasopharyngoscopy and imaging.1–3

Although smoking is a risk factor for most head and neck cancers, this is not the case for nasopharyngeal tumors. The key risk factors are ethnicity, genetic alterations with chromosomal deletions, dietary nitrosamines, chemical fumes, wood dust, and Epstein-Barr virus. Incidence is highest in Southeast Asia where it is >30 per 100,000 population compared with 1 per 100,000 population in the US and European Caucasians. Other ethnic groups with a high incidence of nasopharyngeal carcinoma include Eskimos, Polynesian, and indigenous Mediterranean populations.1–3

Patients who have visible evidence of tumor during nasoendoscopy in clinic should undergo examination under anesthesia for biopsy and formal assessment of the upper aerodigestive tract. Blind biopsies of the fossa of Rosenmüller should be performed at the same time. Once pathology is diagnosed, it should be staged using a multislice CT of the head, neck, and thorax. An MRI of the skull base is useful if the tumor is advanced. If an occult primary tumor of the nasopharynx is suspected, then a positron emission tomography-computed tomography (PET-CT) scan before biopsy is indicated. If nodal neck disease is evident (which is not the case in this patient), the enlarged node or nodes can be investigated with ultrasound-guided fine-needle aspiration cytology.1,2

Oropharyngeal cancer has become increasingly common in recent years. Its incidence has doubled in the United States and the United Kingdom over the past decade. More than half of all new oropharyngeal cases are HPV- positive, and the tonsils and tongue base particularly are common subsites. Human papillomavirus (HPV) is also recognized in some oral cavity tumors such as the tongue, lip, and floor of the mouth. It also carries a better prognosis and treatment may be deescalated. HPV-associated squamous cell carcinoma disease typically presents in younger people in whom the usual risk factors for head and neck cancer (that is, high alcohol intake and smoking) are absent.1,2

Plummer-Vinson syndrome is a rare condition of unknown cause that is typically seen in postmenopausal, Caucasian women presenting with dysphagia, glossitis, splenomegaly, esophageal stenosis, and iron deficiency anemia. It is also associated with postcricoid cancer and esophageal cancer, which both have a much higher incidence in this population. There is no specific association with the other cancer subtypes listed. This syndrome can usually be effectively treated with iron supplementation and mechanical dilation of the esophagus where there is no evidence of malignancy. However, regular surveillance is often advised because of the risk of malignant transformation.1

Nasopharyngeal cancer most commonly presents in males between 30 and 50 years of age. More than half will present with nodal metastases. The other common presenting symptoms are neck lumps, blood in saliva, deafness, nasal obstruction, tinnitus, and cranial nerve palsy. Particular concern should be raised when any patient presents with unilateral otitis media, bilateral level V nodes, and skull base symptoms. Sore throat and gastroesophageal reflux tend to be associated with early stage hypopharyngeal cancer and this may too be associated with referred otalgia. Tonsillar fossa tumors of the oropharynx may present with dysphagia and jaw pain as well as otalgia. A single enlarged neck mass or referred otalgia need urgent assessment and workup. Overall, many of the pharyngeal tumors share presenting symptoms and this highlights the need for accurate and swift assessment in clinic with fine-needle aspiration of neck lumps or core biopsies followed by examination under anesthesia and targeted biopsies in conjunction with appropriate imaging.1–4

Swallowing is the coordinated act that propels a bolus of food from the oral cavity to the esophagus while protecting the airway. It has four key phases which are the oral preparatory, oral, pharyngeal, and esophageal. There is no preparatory phase. Of these, the most important is the pharyngeal phase, as it involves the transit of food into the esophagus while providing airway protection. This key phase may be impaired in patients with pharyngeal tumors, either by the tumor mass itself or secondary to surgical or radiotherapy treatment. The pharyngeal phase is programmed and involves coordination between the medullary inputs of swallow and respiration. Respiration ceases for a fraction of a second during swallow. This requires some cortical input from tongue motion. Triggering of this phase programs five activities: closure of the velopharynx to prevent food reflux, retraction of the tongue base to propel food, contraction of the pharynx to clear residue, elevation and closure of the larynx, and opening of the cricoesophageal and upper esophageal sphincters to allow the food bolus to pass through.1,2

Swallowing may be assessed in a number of different ways. Clinically, it may be assessed at the bedside using small volumes of fluid. During the assessment, the facial, lip, tongue, laryngeal, and respiratory control can each be observed. When checking for postoperative fistula formation, the use of colored fluids can be helpful. The best modality for noninvasive assessment of all phases of the swallow is with videofluoroscopy using a contrast agent such as barium. This is because it is the only procedure that allows observation of the upper aerodigestive tract in all four stages of swallowing. Endoscopic assessment of swallow can be performed such as with the FEEST test. This is a “functional endoscopic evaluation of swallowing with sensory testing” where a trained observer uses an endoscope to watch the swallow process in real time. Sensation can be assessed with puffs of air.1–3

carcinoma? Mandibulotomy is a technique where the mandible is split in order to obtain access to the pharynx or oral cavity in major tumor resection. It generally involves an extended neck incision (as a continuation of a neck dissection wound) passing over the chin in the midline and through the full thickness of the lower lip. The mandible is then opened like a book (mandibular swing) for access. Minimally invasive surgery with robotic assistance can avoid the need for traditional transcervical access with a mandibulotomy and mandibular swing, thereby reducing postoperative morbidity and scarring. Transoral Robotic Surgery (TORRS) is one of a number of recent advances in the management of head and neck cancer patients. It has been performed for both tumor extirpation and reconstruction where required. Other developmental advances include free tissue transfer which has allowed more complex defects to be functionally reconstructed, selective neck dissection which has allowed preservation of unaffected lymph node basins and other key structures such as the internal jugular vein (IJV), spinal accessory, and sternocleidomastoid, and Laser surgery which has added another dimension to surgical tumor resection as an alternative to traditional blade dissection. Advances in radiotherapy with intensity modulated radiotherapy (IMRT) have meant that radiotherapy doses are more directed to the malignant tissues, resulting in less dosing to adjacent healthy tissues. In spite of the benefits of minimally invasive robotic surgery, patients may still require soft tissue reconstruction with local or free tissue transfer, neck dissection, and postoperative radiotherapy depending on tumor type. Dental extractions are not generally performed to help access but are indicated in patients expected to undergo postoperative radiotherapy or those with poor dentition.1,2

modality? Radiation therapy is the main treatment modality for nasopharyngeal carcinoma. Surgery is usually used only in the following selected circumstances: • In salvage or recurrent cases • To obtain tissue for diagnostic purposes • To obtain tissue from clinically involved neck nodes • To treat otitis media secondary to effusion In contrast, surgery is more commonly the first-line treatment for many of the other head and neck tumor subsites, although this will depend on the tumor type and site, as radiotherapy is also used for many patients, often in conjunction with chemotherapy.1–3

In general, hypopharyngeal tumors have the worst outcomes. At least three quarters of patients with hypopharyngeal tumors present late with stage III or IV disease. Patients with early disease (that is, stage I or II) are often asymptomatic at presentation but may present with gastroesophageal reflux and sore throat. Patients with advanced disease most commonly present with a neck mass. Other symptoms include dysphagia, referred otalgia, and respiratory difficulties. The 5-year survival for patients with locally invasive cancer is less than 35%.1–4

Disa et al1 described a classification system for defects of the hypopharynx that require reconstruction. Type I defects involve less than 50% of the circumference, type II involve more than 50% of the circumference, and type III are extensive noncircumferential defects that involve multiple anatomic levels. This is clinically relevant as reconstruction options are based on the extent of the defect created by resection. Local flaps such as pectoralis major are more often used for partial defects, while free tissue transfer flaps are used for larger and circumferential defects.

There are a number of reconstructive procedures used following total laryngopharyngectomy and they include free and pedicled tissue transfers. The primary purpose is to provide a conduit for food and saliva, a safe airway, and the potential for voice rehabilitation. A typical combination is to use a free flap, such as a tubed anterolateral thigh flap (ALT) or free jejunum, and then insert a prosthetic device containing a one-way valve between the posterior trachea and the anterior esophagus. This allows the creation of sound as the air is diverted into the esophagus during speech. There remains debate as to the best flap for circumferential reconstruction of the pharynx, with ALT and jejunum remaining the most popular, each having different advantages. The ALT is useful in thinner patients and is particularly versatile where complex defects are present. Speech outcomes tend to be good and surgery avoids an intraabdominal approach. The free jejunum is a good size match and the moist mucosal tube with retained peristalsis may improve swallowing function. However, the mucus production can impair speech intelligibility and may result in a wet, coarse voice. Also, the jejunum flap is thought to have a long-term reliance on the vascular pedicle and anastomosis, whereas the ALT and other fasciocutaneous flaps will generate blood supply from surrounding tissues fairly soon after reconstruction.1–5

When reconstructing the pharynx with a free ALT flap, the risk of salivary fistula formation can be reduced by inserting a salivary pharyngeal bypass tube within the neopharynx, bridging both proximal and distal anastomoses. Salivary bypass tubes are clear silicone tubes, also called Montgomery1 tubes that come in different sizes. The benefits of a bypass tube are to protect the anastomoses from saliva and stent open the neopharynx, thereby potentially also reducing the risk of stricture formation. The anastomoses are usually sutured with absorbable sutures such as Vicryl, as their presence is only required until healing has occurred, which should be 1–2 weeks during which time the patient is given nothing by mouth. Early feeding and hydration can begin with either a nasogastric or gastrostomy tube. There is no role for total parenteral nutrition (TPN) where enteral feeding is possible. Use of a proton pump inhibitor has no direct effect on fistula formation. Many patients will require postoperative radiotherapy, and this typically begins 4–6 weeks after surgery. Therefore, delaying postoperative radiotherapy is not required and of no routine benefit with regard to early fistula formation. Keeping to safe oncologic principles, radiotherapy should be started early once healing is complete. Long-term complications of radiotherapy include both stricture and fistula formation.

The tongue base is critical for airway protection and swallowing. As such, when much of the tongue base will be sacrificed during tumor resection, a laryngectomy should be considered to decrease the risk of aspiration after treatment. Although prosthetic devices are useful for isolated hard palate defects, soft palate defects are usually best reconstructed with local or imported soft tissue. Soft palate defects larger than 50% lead to velopharyngeal insufficiency. Small pharyngeal defects can be left to heal by secondary intention or closed directly. Large defects are often best reconstructed with free tissue flaps such as the radial forearm or ALT. Local flaps may be used for oropharyngeal reconstruction but are not usually recommended for the tongue, as they can cause deformation and tethering. Furthermore, they often lack the bulk required for adequate reconstruction, and flaps such as the platysma myocutaneous flap have high complication rates. Following total or subtotal glossectomy, outcomes for speech and swallowing are typically poor and there is no proven benefit in using muscle flaps with motor reinnervation.1–3