Introduction
The hypopharynx is the inferior-most portion of the pharynx, bounded by the oropharynx superiorly and the esophagus inferiorly. The hypopharynx is intimately related to the larynx, both anatomically and functionally. Anatomically, the hypopharynx extends from the base of the vallecula down to the apices of the piriform sinuses and the inferior border of the cricoid cartilage. For purposes of classification, the hypopharynx is divided into three subsites: the piriform sinuses, the posterior pharyngeal wall, and the postcricoid area. The mucosa of the hypopharynx is continuous with that of the larynx, and cancers that originate in one site frequently spread to the others. Functionally, the hypopharynx and larynx are responsible for coordinating the competing tasks of airway maintenance and deglutition.
Squamous cell carcinoma (SCCA) is the most common malignancy presenting in the hypopharynx and usually presents at an advanced stage. Alcohol and tobacco are strong risk factors, as with other cancers of the head and neck.
Due to the rich lymphatics of the pharynx, cervical metastases are common with hypopharyngeal primaries, and over two-thirds of patients present with stage III or IV cancer. Perhaps because of this, prognosis is often poor despite aggressive treatment—hypopharyngeal SCCA has the worst prognosis of SCCA at any subsite within the head and neck. The piriform sinus is the most common site for hypopharyngeal cancer.
Traditional treatment for hypopharyngeal SCCA included surgery, usually total laryngectomy with total or partial pharyngectomy, and was followed by postoperative external beam radiation therapy (XRT). However, following landmark studies using chemoradiation with surgical salvage for laryngeal and hypopharyngeal cancers, which showed equivalent survival in the surgical and nonsurgical arms, the use of primary surgical treatment of hypopharyngeal cancer has decreased.
Both surgical and nonsurgical treatments for hypopharyngeal cancers carry significant functional morbidity. Gastrostomy tubes are often required during and after treatment, and swallowing and sometimes airway function following chemoradiotherapy may be permanently compromised, despite a surgically undisturbed larynx ( Fig. 48.1 ).
Given the low cure rates and high rates of functional sequelae, alternatives to laryngectomy and nonsurgical organ preservation continue to be of interest and evolve. Such operations as transoral laser microsurgery (TLM), transoral robotic surgery (TORS), and extended partial laryngopharyngectomy procedures such as SCHLP (supracricoid hemilaryngopharyngectomy) provide palliation and cure rates that rival other treatments and are being revisited for selected lesions.
Key Operative Learning Points
Small cancers of the posterior wall of the pharynx may be resected transorally or through a suprahyoid pharyngotomy.
At least 2.5 to 3 cm of pharyngeal mucosa must remain in the transverse dimension after resection in order to close the pharyngeal mucosa primarily.
Cancer extension across the midline of the posterior hypopharyngeal wall or involving the postcricoid mucosa requires total laryngopharyngectomy with reconstruction.
Cancers extending to the esophagus cannot be excised and the wound closed primarily.
Failure to aggressively preserve uninvolved mucosa may preclude primary closure.
Wound closure under tension due to insufficient mucosa will predispose to wound breakdown, fistula formation, and postoperative dysphagia due to stricture formation.
Submucosal spread is common in hypopharyngeal cancers, and negative margins must be confirmed by frozen section.
Patients must understand that although every attempt may be made to perform partial laryngopharyngectomy, intraoperative findings or frozen section pathology may make this impossible. Therefore, patients should be consented for a possible total laryngopharyngectomy.
Patients with prior radiation or chemoradiation should have pharyngeal closure performed with a vascularized flap either integrated into the remaining pharyngeal mucosa or tubed in the case of total pharyngectomy defect. A pectoralis major flap can be used for closure of the anterior pharynx over remaining mucosa, but a complete pharyngeal defect with discontinuity is best reconstructed with free tissue transfer.
Preoperative Period
History
History of Present Illness
Symptoms often occur late in the course of cancer of the hypopharynx.
Symptoms vary significantly, depending on the location of the cancer.
Sore throat, blood in the saliva, weight loss, dysphagia, and odynophagia may all be symptoms of cancer of the hypopharynx. Referred otalgia is another frequent symptom. Malnutrition may be a major problem when patients present with an advanced stage cancer.
Dysphagia is often a late symptom but can occur earlier in postcricoid carcinomas.
Sore throat and odynophagia may indicate perineural spread and advanced disease.
Globus and foreign body sensation in the throat can be indicators of a hypopharyngeal mass.
Hoarseness, difficulty breathing, and stridor generally indicate advanced cancer with hemilaryngeal fixation.
Past Medical History
Medical Illness
Pharyngectomy is an extensive operation with an often difficult postoperative course. Patients must be medically stable to survive the surgery and postoperative period.
Insulin-dependent diabetics are at increased risk for wound breakdown and fistula formation.
Patients must have adequate pulmonary reserve to be considered for a partial pharyngectomy or a partial laryngectomy.
Iron deficiency anemia, along with hypopharyngeal webs (Plummer-Vinson syndrome), may be associated with cancer of the hypopharynx, although the incidence of this syndrome appears to be decreasing with lower rates of iron deficiency anemia.
Gastroesophageal reflux is associated with esophageal cancer and may also be a major problem in cancer of the hypopharynx.
Surgical History
Prior thyroid or neck surgery may present surgical challenges and increase the risk of injury to the parathyroid glands.
A history of lung surgery or other pulmonary compromise may increase the consequences of aspiration and preclude partial laryngectomy.
Family History
Family history of cancer
History of adverse anesthesia reactions in family members
Social History
Tobacco and alcohol use are strong risk factors for the development of hypopharyngeal cancer.
Smoking also significantly impairs wound healing and is a risk factor for developing a fistula postoperatively.
Honest reporting of alcohol consumption is critical to provide adequate prophylaxis for postoperative withdrawal if alcohol dependence is present.
Medications
Anticoagulants and antiplatelet drugs should be discontinued if medically feasible.
Immunosuppressant medications may make the cancer more virulent.
Physical Examination
- •
A thorough examination of the oral cavity and oropharynx, including palpation of the tonsils and base of tongue, should be performed.
- •
Second primary cancers are not uncommon, even in patients with early-stage cancer.
- •
Trismus indicates involvement of the muscles of mastication.
- •
Fiberoptic examination of the pharynx and larynx is indicated to evaluate the extent of the cancer, assess for second primaries, and evaluate the mobility of the vocal folds.
- •
The Chevalier Jackson sign of saliva pooling in the piriform sinuses is also suggestive of hypopharyngeal carcinoma with distal obstruction.
- •
If partial laryngectomy is considered, pulmonary function must be evaluated, as patients undergoing these procedures must have excellent pulmonary reserve.
- •
Basic laboratory tests in the form of complete blood count (CBC) and metabolic profile are indicated. Liver function tests with measurement of serum albumin may also be useful to assess basic nutritional status.
- •
If open surgery is considered or the patient has a history of prior neck radiation or chemoradiation, thyroid function tests (thyroid stimulating hormone [TSH] and free T4) should be obtained.
- •
Examination under anesthesia with direct laryngoscopy, rigid esophagoscopy, and bronchoscopy must be performed prior to cancer resection.
- •
A biopsy should be obtained during the examination under anesthesia to provide a tissue diagnosis. Other benefits of endoscopy include evaluation of the size and extent of the cancer, palpation of the arytenoids to assess for fixation of the vocal folds, and identification of second primary cancers.
Imaging
- •
Barium swallow esophagram
- •
Provides preoperative assessment of swallowing function, laryngeal penetration, and aspiration
- •
May reveal extension of the cancer into the cervical esophagus
- •
May demonstrate fixation of the cancer to the prevertebral fascia
- •
- •
Computed tomography (CT) and/or magnetic resonance imaging (MRI)
- •
Preoperative imaging is critical to assess the extent of the cancer and help plan the appropriate resection.
- •
CT and MRI are both useful to assess the extent of the primary cancer.
- •
MRI provides better assessment of the degree of invasion of the prevertebral musculature and may be preferable for cancers of the posterior pharyngeal wall.
- •
CT is superior for assessment of invasion of the thyroid or cricoid cartilages.
- •
Either CT or MRI should be performed with contrast whenever possible, as this better demonstrates the vasculature and areas of enhancement.
- •
Given the high rate of cervical metastases at presentation, whichever imaging modality is chosen should include the neck. Cancer of the pharynx may involve the retropharyngeal nodes, which are usually not clinically apparent.
- •
- •
Positron emission tomography (PET) CT
- •
Indicated to identify synchronous second primaries as well as cervical lymph nodes and distant metastases
- •
If PET/CT is not performed, a minimum of a chest CT should be performed.
- •
Indications
- •
In properly selected patients, partial pharyngectomy with postoperative radiotherapy may be preferable to more extensive surgery or definitive chemoradiation therapy.
- •
A general stepwise paradigm for surgical excision of cancers of the hypopharynx is outlined in Table 48.1 .
TABLE 48.1
Algorithm for Management of Hypopharyngeal Tumors
Extent of Surgery
Surgical Approaches
Indications
Reconstructive Options
Simple excision
- •
Transoral CO 2 laser excision or transoral robotic surgery
- •
Small tumors of posterior pharyngeal wall
- •
Small tumors of medial or lateral wall of piriform sinus
- •
None; wounds heal by secondary intent
Partial pharyngectomy
- •
Lateral pharyngotomy
- •
Suprahyoid pharyngectomy
- •
Small tumors of posterior pharyngeal wall
- •
Carefully selected larger tumors of posterior pharyngeal wall
- •
Suture mucosal edges to prevertebral fascia
- •
Skin graft
Partial pharyngectomy with partial laryngectomy
- •
Supraglottic hemilaryngopharyngectomy
- •
Vertical hemilaryngopharyngectomy
Cancer limited to:
- •
AE fold
- •
Medial wall of piriform sinus
- •
Anterior wall of piriform sinus
- •
Primary closure of pharyngeal mucosa bolstered by remaining thyroid cartilage perichondrium and infrahyoid musculature flap
- •
Free flap reconstruction
Partial pharyngectomy with total laryngectomy
- •
Transcervical
Tumor involving piriform sinus with involvement of:
- •
Larynx
- •
Apex of piriform sinus
- •
Lateral wall of hypopharynx
- •
Primary closure if ≥3 cm of pharyngeal mucosa remains
Total pharyngolaryngectomy
- •
Transcervical
- •
Postcricoid carcinoma
- •
Large or pharyngeal wall
- •
Piriform sinus carcinoma with extension across midline
- •
Total Pharyngolaryngectomy will always require either flap reconstruction, gastric pull-up, etc. Primary closure will never be possible in this scenario.
- •
- •
Partial pharyngectomy—no laryngectomy:
- •
Small T1/T2 cancers of the posterior pharyngeal wall without extension to the cervical esophagus may be treated by excision using a transcervical (lateral or suprahyoid) pharyngotomy or transoral resection ( Fig. 48.2 ).
Fig. 48.2
Surgical photograph demonstrates the lateral transcervical approach to the hypopharynx.
- •
Larger cancers of the posterior wall of the hypopharynx can sometimes be completely excised via suprahyoid pharyngectomy and/or lateral pharyngotomy approaches and reconstructed with a free flap. However, excision of large amounts of posterior pharyngeal wall sensate mucosa will have negative effects on swallowing function, and this should be taken into account when planning surgery.
- •
- •
Partial pharyngectomy with partial laryngectomy
- •
Patients undergoing these procedures must have adequate pulmonary function to tolerate partial laryngectomy.
- •
Vertical hemipharyngolaryngectomy
- •
Mainly indicated for cancers of the medial piriform sinus without extension to the piriform apex
- •
Involvement of the ipsilateral arytenoid is acceptable.
- •
The excision can be extended to allow resection of cancer extending to the supraglottis and a portion of the lateral wall of the piriform sinus.
- •
The most extreme extension of this procedure is a full supraglottic hemipharyngolaryngectomy, with resection of the epiglottis, vallecula/pre-epiglottic space, and a portion of the base of the tongue.
- •
- •
SCHLP
- •
Extends the previous procedure by also excising the ipsilateral piriform sinus and supracricoid larynx
- •
Patients are likely to have aspiration postoperatively, and only patients with excellent pulmonary reserve are candidates for this procedure.
- •
The indications for this procedure were traditionally for early pyriform and arytenoid cancers, but it has been used in experienced hands for more advanced cancers.
- •
- •
- •
Partial pharyngectomy with total laryngectomy
- •
The most common indication is piriform sinus carcinoma that extends medially to the larynx, inferiorly to the apex of the piriform sinus, or laterally to the lateral wall of the hypopharynx.
- •
Partial pharyngectomy is indicated if 2.5 to 3 cm in horizontal dimension of posterior pharyngeal wall mucosa remains following excision of the cancer. In such cases, primary closure of the pharyngeal mucosa can result in a functional swallowing mechanism postoperatively.
- •
- •
Total laryngopharyngectomy
- •
In addition to the indications for total laryngectomy listed previously, common indications for total laryngopharyngectomy include piriform sinus carcinoma that extends across the midline and postcricoid cancer. The hypopharynx is shaped like a funnel, and while there may be sufficient pharyngeal mucosa in the superior hypopharynx to close a defect, the total area of pharyngeal mucosa in the postcricoid area is so limited that direct closure is not possible following cancer resection.
- •
Total pharyngectomy is necessary when less than 2.5 cm of posterior pharyngeal wall mucosa remains horizontally following cancer resection; therefore, large cancers of the posterior hypopharyngeal wall are a common indication for this procedure.
- •
- •
Neck dissection of at least levels II to IV should be performed in all patients. Metastatic cancer is found in 60% to 80% of patients with cancer of the hypopharynx, and 20% to 40% will have occult neck metastases to the cervical lymph node. Bilateral selective neck dissection (or radiation to the contralateral neck) is indicated for cancers of the medial wall of the piriform sinus, which tend to behave more like supraglottic carcinomas.
Contraindications
- •
Contraindications to partial pharyngectomy without laryngectomy
- •
Cancer involving the larynx
- •
Location of the cancer in the piriform sinus or postcricoid area
- •
Extension of posterior wall cancer to the lateral pharyngeal wall
- •
Large cancer of the posterior pharyngeal wall, although acceptable in certain carefully selected patients, is generally contraindicated, as the loss of large amounts of sensate mucosa severely impairs swallowing function and places the patient at risk for aspiration.
- •
- •
Contraindications to partial pharyngectomy with partial laryngectomy
- •
Extension of the cancer to the apex or lateral wall of the piriform sinus
- •
Large cancers of the posterior pharyngeal wall
- •
Cardiopulmonary comorbidities with inability to tolerate postoperative aspiration require total laryngectomy.
- •
- •
Contraindications to partial pharyngectomy with total laryngectomy
- •
Insufficient pharyngeal mucosa to allow for a functional primary closure ( Fig. 48.3 )
- •
