The larynx serves three main functions. Its primary function at the junction of the respiratory and digestive tracts is to protect the airway from food and saliva. It also serves some respiratory function, opening and closing with respiration, and affording the ability to cough and perform the Valsalva manoeuvre. Finally the larynx allows phonation. Protection of the airway is the most vital and basic laryngeal function.

The larynx is divided into three portions: the glottis, the supraglottis, and the subglottis. The supraglottic larynx consists of the epiglottis, aryepiglottic folds, and false vocal chords (ventricular bands). It stops inferiorly at the level of the vestibular apex. The glottic larynx consists principally of the true vocal cords. The subglottic larynx extends from a plane 1 cm inferior to the ventricular apex to the inferior edge of the cricoid cartilage.

The larynx contains three paired cartilages: the arytenoid, cuneiform, and corniculate cartilages. Of these only the arytenoids are clinically important; the other two pairs act simply as batons in the free edge of the arypiglottic fold. There are also three unpaired cartilages: the thyroid, cricoid, and epiglottic cartilages. The thyroid and cricoid cartilages are composed of hyaline cartilage and begin to ossify in early adulthood. The epiglottic cartilage consists of elastic cartilage.

The cricoarytenoid and cricothyroid joints are true synovial joints. The larynx is covered by pseudostratified, columnar, ciliated respiratory epithelium, except for the free edge of the true vocal fold and the edges of the epiglottis and aryepiglottic folds, which are exposed to constant trauma and become covered with a non-keratinizing squamous epithelium.

Blood is supplied to the larynx through branches of the superior and inferior thyroid arteries that anastomose with each other. The supraglottic larynx is richly supplied with lymphatics, which drain bilaterally through the thyrohyoid membrane to the upper and middle jugular chain of lymph nodes. The epithelium covering the true vocal cords of the glottic larynx is separated from the underlying vocal ligament by a thin potential space of loose connective tissue known as Reinke's space. This tissue has very sparse lymphatic supply. Although the subglottic larynx is richly supplied with lymphatics, these tend to drain unilaterally by way of the cricothyroid membrane to the middle and lower jugular nodes, as well as to the paratracheal and tracheo-oesophageal nodes.

The motor innervation of the intrinsic laryngeal musculature is supplied by two branches of the vagus nerve: the recurrent laryngeal and superior laryngeal nerves. The superior laryngeal nerve has two branches: the internal and external laryngeal nerves. All the intrinsic muscles except for the cricothyroideus are supplied by the recurrent laryngeal nerve. The cricothyroideus is supplied by the external laryngeal branch of the superior laryngeal nerve.

Sensory innervation to the larynx is also supplied by the vagus nerve. The region below the true vocal folds is supplied by the recurrent laryngeal nerve, while the supraglottic larynx is supplied by the internal laryngeal branch of the superior laryngeal nerve. These two nerves communicate with each other via the anastomosis of Galen. On the left, the recurrent laryngeal nerve passes around the aortic arch lateral to the ligamentum arteriosum. On the right the recurrent nerve passes around the subclavian artery. Rarely, the right recurrent nerve is non-recurrent, passing directly from the vagus to the larynx. In such cases, the origin of the right subclavian artery from the aorta is anomalous.

The only true abductor of the true vocal folds is the posterior cricoarytenoid muscle, which is supplied by the recurrent laryngeal nerve. The remaining intrinsic musculature adducts or tenses the true vocal folds.

Laryngeal cancer is largely a preventable disease and is related to the use of tobacco products. Laryngeal cancer accounted for approximately 12 200 new cancer cases and 3800 cancer deaths, or 1.2 per cent of new cancer cases and 0.77 per cent of cancer deaths, in the United States of America in 1988. Laryngeal cancer occurs 4.4 times more frequently in men than in women, although, like lung cancer, it is becoming increasingly common in women. Tobacco smoking is by far the greatest risk factor for laryngeal cancer. Others include alcohol abuse, radiation exposure, asbestos exposure, and genetic factors.

Cancers confined to the vocal ligament have an excellent prognosis, partly because of the sparse lymphatic drainage of the area. The clinical assessment of vocal fold mobility is mandatory in the assessment of glottic cancers. Even early, superficial tumours that spread to the anterior commissure tend to remain confined to the cord without invading the cartilage, as long as there is no superior or inferior extension. A dense condensation of connective tissue (Broyle's ligament) consisting of the confluence of the vocal ligament, upper end of the conus elasticus, thyroepiglottic ligament, and the internal perichondrium of the thyroid cartilage helps to prevent direct involvement of thyroid cartilage. Lesions of the anterior commissure which spread superiorly to the inferior aspect of the epiglottis, usually invade the thyroid cartilage. Fixation of the vocal cord is an ominous clinical finding; it is usually due to direct invasion of the thryoartenoid (vocalis) muscle by cancer. Such tumours have free egress to the paraglottic space and tend to undergo lymphatic spread to the cervical lymph nodes. Transglottic tumours, those involving both supraglottic and glottic larynx by continuous spread across the apex of the ventricle, spread outward to involve the paraglottic space through the deficiency at this level between the conus elasticus and quadrangular ligament. Once the paraglottic space is involved, cancer may invade the thyroid cartilage or spread outside the larynx through the cricothyroid membrane. Most such neoplasms require total laryngectomy for their complete removal.

Supraglottic cancers have a propensity for bilateral cervical metastasis. Those arising below the level of the hyoid bone may penetrate the multiple small dehiscences in the epiglottic cartilage and invade the pre-epiglottic space. Those arising above the level of the hyoid bone are above the level of the pre-epiglottic space and tend to have a better prognosis. Purely supraglottic cancers rarely involve the thyroid cartilage directly.

Solely subglottic cancers are rare; however, glottic cancer may spread inferiorly to involve the subglottis. Such cancers may spread outside the larynx through the cricothyroid ligament, with direct tumour extension into the thyroid gland. A hemithyroidectomy on the side of the lesion should be performed at the time of surgical resection. Subglottic neoplasms tend to metastasize to the paratracheal and tracheo-oesophageal lymph nodes, which must be removed at the time of neck dissection. Subglottic cancers, or others with subglottic extension, tend to have a greater incidence of peristomal local recurrence after total larygectomy.

Glottic cancers cause hoarseness early in the course of the disease; only minimal irregularity of the vocal fold results in a fairly marked degree of voice change. This, together with the sparse lymphatic drainage of the glottic larynx with little early potential for regional or distant metastasis accounts for the good prognosis of early glottic cancer. Early glottic cancers appear as red (erythroplakia) or white (leukoplakia) patches on the vocal folds. There may be a mass or ulceration of the vocal folds. Although early glottic cancers do not impair gross vocal fold motion, stroboscopy shows impairment of the superficial mucosal wave pattern. Advanced glottic cancers present with symptoms of dyspnoea, dysphagia, odynophagia, pain, bleeding, and a neck mass. Impaired vocal fold motion with a fixed hemilarynx and large exophytic and/or ulcerated mass may be seen. There may be evidence of spread to cervical lymph nodes, including the prelaryngeal or delphian node. Most commonly, glottic cancers involve the middle and inferior jugular lymph nodes.

In some patients, the first sign of disease is acute airway obstruction. Controversy has surrounded the proper handling of these patients. Some authorities feel that a tracheotomy increases the risk of a stomal recurrence of the cancer secondary to direct tumour seeding in the tracheotomy wound. Others have suggested that patients with large tumours, who are likely to present with acute airway obstruction, are more likely to have subglottic extension and involvement of the paratracheal and tracheo-oesophageal lymph nodes, and that these factors are more directly related to stomal recurrence.

Emergency laryngectomy, intubation in the intensive care unit until laryngectomy can be undertaken, and laser debulking of the tumour have all been advocated as methods by which tracheotomy can be avoided in patients with an obstructing laryngeal cancer. Certainly, if tracheotomy is undertaken, laryngectomy should follow within a week or two, and postoperative irradiation should include a booster dose to the tracheostoma and upper mediastinum.

Supraglottic cancers may be more silent than glottic cancers and, for that reason, present at a more advanced stage. Early symptoms are more likely to relate to painful deglutition (odynophagia) than to hoarseness or dyspnoea. Supraglottic cancers have a marked tendency to metastasize bilaterally through the thyrohyoid membrane to the jugular and cervical lymph nodes.

Primary subglottic cancers are rare. They tend to present with dyspnoea.

All primary care physicians practising in areas where specialists are lacking should become adept in the techniques of indirect laryngoscopy. The alternative technique of fibreoptic flexible laryngoscopy is simple to learn, although the equipment is expensive and fragile. Indirect laryngoscopy and fibreoptic laryngoscopy are the basis for the diagnosis and monitoring of patients with laryngeal cancer.

A complete head and neck examination should be undertaken: 20 per cent of these patients harbour a second synchronous or metachronous cancer of the aerodigestive tract. Careful inspection of the nasal cavity, nasopharyx, oral cavity, oropharyx, hypopharyx, larynx, and both sides of the neck should be performed in an attempt to define the limits of the disease, and to detect second primary cancers and regional cervical metastases. Patients should be questioned about recent bone pain, neurological changes such as seizure disorders, dyspnoea, haemoptysis, dysphagia, odynophagia, and weight loss.

A chest radiograph and liver function studies (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactic dehydrogenase) should be obtained in all patients. If there is a history of recent unexplained bone pain, a bone scan should be obtained; a history of recent central nervous system derangement is an indication for CT scan of the brain. If the chest radiograph is abnormal, chest fluoroscopy or a CT scan of the chest may be indicated if the findings are equivocal or if resection is contemplated. If the liver function studies are abnormal a CT scan of the liver is indicated. Elevation of serum alkaline phosphatase is the most frequent laboratory abnormality in metastatic liver disease, though this is fairly non-specific.

The fundamental means of evaluation of laryngeal malignancy remains direct laryngoscopy and biopsy in the operating room. Here the larynx can be palpated, structures obstructing the view can be moved out of the way, the operating microscope can be used to obtain a magnified, illuminated view, and appropriate biopsies can be obtained. Although direct laryngoscopy was commonly undertaken using local anaesthesia in the past, it can be performed safely and more adequately under general anaesthesia. Direct laryngoscopy could be combined with oesophagoscopy, bronchoscopy, and careful intraoperative evaluation of the oral cavity, oropharyx, and nasopharyx. Chest radiography and bronchoscopy complement each other; chest radiographs detect tumours of the peripheral airways, while bronchoscopy detects non-obstructing lesions of the major airways.

Second primary cancers of the oesophagus are among the most frequently reported, and for this reason oesophagoscopy is recommended. If this is not undertaken, an oesophagogram should be obtained before endoscopy. Oesophagoscopy and oesophagography may be complementary: the former identifies lesions of the distal oesophagus, while the latter detects lesions of the proximal oesophagus, where multiple overlapping shadows make radiological interpretation more difficult.

Cancer of the larynx is staged according to a TNM system. The importance of staging lies in its ability to allow the surgeon to document the original extent of the disease, to assess the prognosis, and to compare his results with those of others. All patients should undergo formal staging at the time of endoscopy. Appropriate drawings of the tumour should be made and included in the patient's permanent record.

The most important factor in the surgical approach to these cancers is a complete understanding of the true three-dimensional extent of the tumour. Only then can an appropriate operation be conceived and planned. Local control of these cancers through surgery means obtaining clear surgical margins, and this goal can only be achieved if the surgeon has a good idea of where those margins lie.

Appropriate treatment of laryngeal cancer is dependent on the extent of disease. As noted above, appropriate treatment planning requires pretreatment evaluation of each individual tumour. In general, early T1 cancers of the glottic larynx are treated with radiation alone. T2 lesions are often treated with radiation; if there is some limitation of vocal cord motion without complete fixation, a vertical hemilaryngectomy may be required.

The decision about whether to use postoperative radiation therapy is based on the final pathological findings. Indications for postoperative radiation therapy after partial laryngectomy for T2 glottic cancer are positive surgical margins, the presence of marked vascular or perineural invasion, and the presence of multiple positive lymph nodes in any neck dissection performed concomitantly.

T3 and T4 glottic lesions are generally treated with a combination of total laryngectomy and postoperative radiation therapy (5000–6000 Gy). Supraglottic cancers not extending to the true vocal cords or piriform sinus, or to within 1 cm of the circumvallate papillae of the tongue may be treated with a supraglottic laryngectomy. Grossly positive lymph nodes are removed by neck dissection, and both sides of the neck receive postoperative radiotherapy. If each side is apparently normal, bilateral modified neck dissections (sparing the spinal accessory nerve and jugular vein) for staging may be performed in the hope of finding no disease. If the primary cancer has been removed with clear surgical margins, and there is no extensive perineural or vascular invasion in the neck dissection specimen, postoperative radiation therapy can be avoided. Alternatively, the clinically cancer-free neck can be left undissected; radiation can be given to both the primary neoplasm and each side of the neck.

Advanced supraglottic cancers with major extension in the base of the tongue are best treated with planned combined surgery and postoperative radiation therapy. If appreciable amounts of the tongue base have to be resected, postoperative deglutition may be so severely affected as to mandate either an initial total laryngectomy, if the problem is anticipated, or a delayed completion laryngectomy, if it is not. Supraglottic cancers fixing the hemilarynx or extending into the piriform sinus are usually best treated with total laryngectomy and postoperative radiation therapy. In some instances near-total laryngectomy may be safely used. Subglottic cancers almost always require a total laryngectomy for safe removal.

Million and Cassis have reported an 8 per cent local failure rate and a 99 per cent ultimate control rate above the clavicles following surgical salvage of radiation failures for stage 1 cancers of the glottic larynx. In their series total laryngectomy was required in four of 90 patients. For stage 2 glottic cancers there was a 33 per cent local failure rate with radiation alone. Wang reported a 90 per cent 3-year survival without evident disease for T1 glottic cancers treated with radiation alone and a 69 per cent 3-year rate of survival with no evidence of disease for T2 cancers. After surgical salvage his control rates rose to 95 per cent for T1 glottic cancers and 82 per cent for T2 glottic cancers. Primary radiation therapy for T3 and T4 glottic cancers is associated with a high local failure rate (68 per cent for T3 glottic cancers treated by Wang) and is generally not indicated as initial sole treatment. When radiation therapy is used in combination with surgery for advanced glottic cancers, it is generally given postoperatively. This plan reduces the operative complications and yields results equally as good as with preoperative radiation. Wang has reported that 70 per cent of patients with T3 and T4 glottic cancers treated with combined surgery and postoperative radiation showed no evidence of disease after 3 years.

There was no evidence of disease in 80 per cent and 59 per cent, respectively, of patients with stage 1 and stage 2 cancers of the supraglottic larynx, 3 years after treatment with radiation alone. With surgical salvage, these rates increase to 87 per cent and 72 per cent, respectively. In patients with T3 and T4 supraglottic cancers, who underwent surgery and postoperative radiation therapy, 67 per cent showed no evidence of disease after 3 years.

Primary subglottic laryngeal cancer is rare. Wang has reported that 40 per cent of patients who underwent radiation therapy alone showed no evidence of disease after 5 years.

Early T1 cancers of the glottis which are confined to the mid-portion of a vocal cord which is normally mobile, may be treated endoscopically with either microdissection instruments or the CO&sub2; laser. Following laser treatment recurrence was seen in 25 per cent of 21 patients with T1 glottic cancers and carcinoma in situ. Three responded to radiation therapy, while the other responded to repeat laser excision. The anterior commissure is the most frequent site of recurrence: neoplasms at this site should not be treated by laser.

In this procedure the larynx is opened vertically, and the soft tissues of one true and false vocal cord are removed. This procedure is indicated only for early tumours confined to a single mobile vocal cord. Cure rates are greater than 90 per cent.

This procedure has many variations. It essentially differs from laryngofissure and cordectomy in that the underlying thyroid cartilage is removed with the specimen. The ipsilateral arytenoid cartilage is usually also removed (Fig. 1) 2362. Variations on the theme include the anterolateral and anterior partial laryngectomy, in which both arytenoids may be spared. Despite the thyroid cartilage being removed in this procedure, it is not appropriate for cancers invading cartilage, which are best treated with a total laryngectomy.

After vertical laryngectomy, deglutition generally remains good because of the remaining epiglottis and sensory innervation of the supraglottic larynx, but the voice is usually hoarse. Some attempts have been made to lessen this hoarseness by insinuating soft tissue into the laryngeal defect, usually in the form of strap muscle. This procedure must be performed with great care to avoid compromising the airway.

Anterolateral laryngectomy is a variation of the hemilaryngectomy discussed above, in which the anterior portions of the true vocal cords, together with the underlying cartilage, are removed. The arytenoids are spared.

Supraglottic laryngectomy is indicated for cancers of the supraglottic larynx not involving the true vocal cords: it entails removing the supraglottic larynx down to the level of the laryngeal ventricles (Fig. 2) 2363. Neoplasms situated above the level of the hyoid bone usually have a better prognosis. The region of the anterior commissure must be carefully evaluated at the time of endoscopy. Involvement of the medial wall of the piriform sinus is a relative contraindication to this procedure, although some tumours barely spilling over the aryepiglottic fold into the most superior aspect of the medial piriform sinus might still be considered appropriate for such an operation.

Although the tongue base can be resected to within 1 cm of the circumvallate papillae, the risk of serious functional morbidity is greatly increased. Morbidity associated with tongue base resection usually relates to deglutition. Because the epiglottis is resected and the innervation is disturbed, food tends to slide over the tongue base and immediately into the glottic larynx, causing aspiration. If pulmonary reserve is good, most patients will compensate. However, if pulmonary reserve is poor, the patient may be unable to feed himself, or worse, may suffer chronic aspiration, ultimately requiring a secondary procedure to complete the laryngectomy. The voice is often good after this procedure, as opposed to the breathy voice heard after vertical hemilaryngectomy.

The near-total laryngectomy removes the thyroid and cricoid cartilage, leaving only a single innervated arytenoid and a ‘speaking shunt’. Unlike other partial laryngectomy procedures, near-total laryngectomy assumes that the patient will be dependent on a tracheostomy for the rest of his or her life. The advantages of this procedure, compared with a laryngectomy and voice rehabilitation with a tracheo-oesophageal puncture, are the quality of the voice and the ease of care afterwards. Large tumours that affect one vocal cord or which spill over into the upper aspects of one piriform sinus are suitable for this procedure. Cartilage invasion remains a relative contraindication to this procedure.

Total laryngectomy is the standard against which other procedures must be weighed in the treatment of advanced laryngeal cancers. Vocal cord fixation, cartilage invasion, and involvement of the piriform sinuses have been traditional indications for this procedure.

Total laryngectomy involves removal of the larynx from the remaining pharynx and transection of the trachea (Fig. 3) 2364. The remaining pharynx is then closed on itself, usually in a ‘T’ fashion; the proximal end of the trachea is sewn to the skin as an end tracheostoma.

Extended total laryngectomy is a procedure usually used for tumours involving the piriform sinus. In these cases more than the usual amount of piriform and pharyngeal mucosa must be removed, narrowing the resulting neopharynx. In general, most of the mucosa of a single piriform sinus can be resected while still affording an adequate closure. If larger amounts of mucosa are resected, the pharynx can still be closed successfully, but at the expense of pharyngeal stenosis and subsequent morbidity in the form of inability to eat substances other than liquids. Tight closure over a nasogastric tube is too tight. It is better to supplement the closure with additional tissue, such as a pectoralis major myocutaneous flap.

In this procedure, the pharynx is removed circumferentially down to the prevertebral fascia along with the larynx. Total laryngopharyngectomy is used for cancers that spread circumferentially around the pharynx, or nearly so, in which total safe extirpation of the cancer dictates circumferential pharyngectomy; it is also recommended for tumours spilling over into the postcricoid region of the hypopharynx. After this procedure the patient is left with a circumferential, tubular defect, which must be reconstructed. This may be achieved by creating an end pharyngostome and oesophagostome through the neck skin flap in addition to the tracheostome, and then repairing the defect after adjunctive radiotherapy has been given. If this treatment plan is followed, a period of time is allowed to observe possible tumour recurrence before reconstruction. Delayed reconstruction can be undertaken in several ways: local skin flaps, as in Wookey's procedure; regional skin flaps, as in the deltopectoral flap, myocutaneous flaps, as with tubed pectoralis major myocutaneous flap; or with distal free flaps, as with the free jejunal flap.

Recently, however, opinion has swung towards immediate reconstruction. Patients with advanced cancers requiring total pharyngectomy have a poor outlook for prolonged survival. They should not be subjected to multiple reconstructive procedures, which often require lengthy hospital stays. Immediate reconstruction allows more rapid rehabilitation, and may be accomplished in a one-stage procedure, using the pectoralis major myocutaneous flap, a free jejunal flap, or a gastric pull-up. If the latter is chosen, a total oesophagectomy is generally performed.

Total laryngopharyngo-oesophagectomy involves blunt dissection of the oesophagus from the posterior mediastinum, in conjunction with a laryngopharyngectomy (Fig. 4) 2365. This procedure is required for the treatment of tumours spreading inferiorly past the cervical oesophagus. Some surgeons feel that the propensity for skip lesions and submucosal spread of advanced tumours involving the hypopharynx make this procedure the best treatment for all such tumours.

The pectoralis major myocutaneous flap is probably the most useful flap for the treatment of laryngeal cancer. Additional tissue is required for closure only after resection of the most advanced cancers, and there is usually the option of leaving defects unreconstructed and of creating an end stoma if these methods are not available.

All patients undergoing total laryngectomy initially lose their voice, but most of them can be taught to speak in an understandable and socially acceptable manner. Anyone performing laryngectomies must work closely with a speech therapist.

In the past, most patients relied on oesophageal speech, in which air was swallowed and then belched, to cause vibration within the pharynx, and then articulated into speech using the teeth, tongue, and palate. A number of electrical devices (electrolarynges) that produce a more fluid tone are now available. These devices are either held up against the skin of the neck overlying the pharynx or are placed in the mouth and use a small reed. The most recent advance combines tracheo-oesophageal puncture with insertion of a speaking valve prosthesis to allow air to pass from the trachea back into the pharynx when the tracheostome is occluded, but which prevents saliva from running in the opposite direction (Fig. 5) 2366. Use of this instrument requires manual dexterity, good vision, and self-motivation on the part of the patient to clean and change the prosthesis daily.

In addition to assisting the patients to acquire some means of speech, the speech therapist is invaluable in helping with problems in deglutition after partial laryngectomy. Clear liquids are most difficult to manage because they run into the larynx before the patient can mobilize compensatory mechanisms. Soft, but thicker, substances, such as puddings, fruit sauces, or purées are thus the best foods to begin with after surgery. If continued difficulties are encountered, a modified barium swallow, in which substances of various consistency and size are swallowed under the fluoroscopic observation of a trained observer, may define the abnormalities so that appropriate remedies can be invoked.

The hypopharynx is a tube interrupted anteriorly by the larynx. It is divided anatomically into three subsites: the piriform fossae, the postcricoid area, and the posterior hypopharyngeal wall.

Tobacco and alcohol abuse are by far the most significant aetiological agents. Women with the Plummer–Vinson syndrome (also known as the Patterson–Brown–Kelly syndrome or sideropenic dysphagia), which is characterized by iron-deficiency anaemia, postcricoid oesophageal web, and dysphagia, are at increased risk from squamous cell carcinomas of the postcricoid hypopharynx. Pharyngeal cancer occurs more frequently in men than women, with a ratio of 2.3 : 1. Pharyngeal cancer, including cancers of the nasopharynx, oropharynx, and hypopharynx, was estimated to account for 0.8 per cent (8300) of new cancer cases and 0.9 per cent (4200) of cancer deaths in the United States of America in 1988.

Squamous cell cancer of the hypopharynx is reputed to have a greater propensity for submucosal spread and skip lesions than similar cancers in other areas of the upper aerodigestive tract. Cancers involving the apex of the piriform fossa may spread to involve the thyroid gland. In addition to the jugular lymph nodes, the retropharyngeal, paratracheal, and tracheo-oesophageal lymph nodes are at increased risk of involvement. Bilateral cervical metastases are common.

Unlike laryngeal glottic cancer, in which hoarseness is present early, hypopharyngeal cancers tend to remain asymptomatic until they reach an advanced stage. Patients often present with only a neck mass, indicative of cervical metastases. Dysphagia and odynophagia are symptoms of more advanced cancer. Ipsilateral otalgia is frequently present and is due to the common sensory innervation of the pharynx and a small portion of the external ear by the vagus nerve, which carries referred pain to the ear. Advanced cancers of the larynx can present with airway obstruction or hoarseness: this is often a result of fixation of a vocal cord by cancer infiltrating from the piriform sinus.

Assessment is similar to that for laryngeal cancer. Laryngoscopy, bronchoscopy, and oesophagoscopy are even more important to the preoperative evaluation of patients with hypopharyngeal cancer. These cancers often cannot be adequately seen in the clinic because of a tendency for the mucosa of the hypopharynx to infold. Because submucosal spread and skip lesions are common, careful examination for separate lesions in the lower oesophagus is required to delineate the inferior extent of the cancer. Since decisions such as whether or not the entire pharynx or oesophagus need to be removed cannot be made until the position and extent of the cancer are known, endoscopy should be carried out as a separate procedure to permit discussion of available options with the patient.

As with laryngeal cancer, hypopharyngeal cancer is staged according to a TNM system devised by the American Joint Commission on Cancer.

Hypopharyngeal cancer is best treated with a combination of surgery and postoperative radiation. Although cancers of the posterior pharyngeal wall can occasionally be approached surgically with some form of pharyngotomy or median labiomandibulotomy, cancers of the postcricoid area and piriform sinus have traditionally been treated with an extended total laryngectomy. Ogura introduced the concept of conservative laryngeal surgery for selected early piriform sinus cancers in the 1960s, but these procedures are still controversial.

Radiation therapy is rarely used alone for the treatment of hypopharyngeal cancers because these tumours tend to present late. However, some early T1 cancers may be treated with radiation alone. Treatment of even small cancers often requires extensive surgery, including total laryngectomy, because of the difficulties encountered in examining the hypopharynx and identifying such tumours. Extensive surgery of small T1 lesions may often be avoided by the use of primary radiotherapy, but at the expense of some decreased long-term survival. A combination of surgery and postoperative radiation produces the best results. Adjuvant chemotherapy is offered to these patients if an experimental protocol is available.

This technique is useful for the removal of small lesions of the posterior pharyngeal wall, which are rare. The pharynx is entered either from the anterior, over the hyoid bone and through the vallecula, or from the side, behind the lateral extent of the thyroid cartilage ala. The resulting defect may be left to granulate, close primarily, or, more usually, closed with a skin graft. A temporary tracheostomy is required.

This approach is occasionally useful for the treatment of early neoplasms of the posterior hypopharyngeal wall. The midline raphe of the tongue affords a bloodless plane of dissection. The mandible is cut in a stepwise manner and is reapproximated with a compression plate. The inferior alveolar nerves should be protected.

An extended supraglottic laryngectomy or near-total laryngectomy may permit extirpation of selected cancers of the superior piriform sinus. Destruction of thyroid cartilage or involvement of the piriform apex is a relative contraindication to such an approach. Involvement of the postcricoid region is a relative contraindication to any type of conservation laryngeal surgery.

This remains the standard operation for the surgical treatment of hypopharyngeal cancers, against which others must be compared. In the treatment of piriform sinus cancers, the dissection often only requires extension to include the mucosa of the piriform sinus. If the piriform apex is involved, the ipsilateral hemithyroid should be removed with the specimen. Reconstitution of the pharynx can be achieved with as little as 2 cm of horizontal width of remaining pharyngeal mucosa. There is no absolute guideline as to when supplemental tissue is required for pharyngeal closure; a tight closure around the nasogastric tube is too tight. If the closure is so tight as to compromise blood flow or cause irritation from the nasogastric tube, deglutatory morbidity or postoperative fistulization results. A closure may be successful in that it heals, but it is a functional failure if the patient can only tolerate a liquid diet. It is easier to supplement the closure with additional tissue, usually a pectoralis major myocutaneous flap, than to perform reconstruction later.

This is often necessary to ensure complete removal of large hypopharyngeal cancers. Total oesophagectomy is sometimes required to ensure an adequate inferior margin. Unfortunately, tumours tracking superiorly can travel up into the nasopharynx and become unresectable. The retropharyngeal nodes of Rouviere are often involved.

Some surgeons consider that submucosal spread and skip lesions make total oesophagectomy indicated for the treatment of many advanced hypopharyngeal cancers. Others prefer reconstruction for all circumferential pharyngeal defects by gastric pull-up, together with total oesophagectomy. In some patients the cancer visibly spreads down into the thoracic oesophagus; others have an obvious skip lesion or primary cancer of the more distal oesophagus. Total oesophagectomy is the only adequate surgical approach. The prognosis of patients with cancers of the thoracic oesophagus that invade all the way through the wall is so dismal following surgical therapy alone that some other approach is indicated. Initial therapy with radiation and chemotherapy is required, surgery being undertaken later, and only if a good response is achieved. This approach, however, is experimental and should generally be undertaken only as part of a controlled trial.

The tubed pectoralis major myocutaneous flap, a gastric pull-up, and free jejunal flap are the most widely used methods for reconstruction of circumferential pharyngeal defects. The tubed pectoralis flap is a difficult procedure in women with large breasts and in those with a large amount of subcutaneous tissue. Most patients with pharyngeal cancer are quite cachectic, however, easing the reconstructive problem. Although flaps may become stenotic, especially at the lower anastomosis to the cervical oesophagus, the problem can often be avoided by making a vertical cut inferiorly in the anterior wall of the cervical oesophagus and cutting the upper end of the pectoralis flap on the chest wall in a fusiform manner such that, when it is tubed, it has a slanted end. When the flap is transposed into the neck, this becomes the lower end, which can then be sewn to the cervical oesophagus on a bias, avoiding a perfectly circumferential suture line.

The free jejunal flap (cut from its native blood supply) or another free flap may also be reliably used for reconstruction. The rate of vascular anastomotic failure in any free flap is about 10 per cent. This may prove fatal if a severe infection develops around great vessels in the neck with direct communication with the mediastinum. A free jejunal flap can also be cut on a bias on what will be the distal end; the anterior wall of the remaining oesophagus can be incised to avoid a perfectly circular anastomosis and to help prevent stricture. The bias on the jejunum must be cut with the longer side toward the mesentery to avoid devascularizing a portion of the jejunum. In addition, at the superior end of the jejunum, a longitudinal incision is made in the antimesenteric wall to provide a longer perimeter to which to sew the pharynx, which has a much larger natural circumference than the jejunum. The status of the free graft can be monitored postoperatively through a fibreoptic endoscope inserted through the nose. Alternatively, a small portion of the flap can be exteriorized through the skin at a suture line so that it can be seen. The patency of the vascular anastomosis can be followed with a transcutaneous Doppler probe.

Gastric pull-up normally entails blunt dissection of the oesophagus from the posterior mediastinum, pulling the stomach up through this space to be anastomosed to the pharynx. The stomach can normally only be pulled up to the level of the circumvallate papillae of the tongue. Previous abdominal surgery may compromise the vascularity of the stomach. There are inherent risks in bluntly dissecting the oesophagus out of the posterior mediastinum; rupture of the azygous vein, chylous fistulae, and disruption of the posterior tracheal wall are the most common. The physiological derangements seen after this procedure are greater than those incurred in simple circumferential reconstruction of the pharynx with a pectoralis major myocutaneous flap.

Disease-free survival at 3 years was seen in 64 per cent of patients with T1 lesions of the posterior pharyngeal wall, 29 per cent of those with T2 lesions, 22 per cent of those with T3 lesions, and none of those with stage T4 disease. After radiation therapy alone for piriform sinus cancers, 3-year disease-free survival rates were 33 per cent for T1 cancers, 57 per cent for T2 cancers, 17 per cent for T3 cancers, and 8 per cent for T4 cancers. The proportions of patients treated with combined surgery and radiation who showed no evidence of disease after 3 years were: 75 per cent (T1 lesions), 40 per cent (T2 lesions), 53 per cent (T3 lesions), and 21 per cent (T4 lesions).

Physical examination predicts the presence or absence of metastatic disease in the neck poorly. CT scans and MRI studies can visualize enlarged lymph nodes in the neck, but cannot always differentiate reactive lymph nodes from those containing cancer.

Radical neck dissection refers to the complete removal of lymph node-containing tissue from the neck, along with the sternocleidomastoid muscle, internal jugular vein, and spinal accessory nerve. Modifications of the radical neck dissection generally preserve some combination of the sternocleidomastoid muscle, internal jugular wall, or spinal accessory nerve, while still attempting total removal of the lymph node-containing compartments. Of these three structures, preservation of the spinal accessory nerve is by far the most important in preventing postoperative morbidity. The spinal accessory nerve is a posterior neck structure only in its inferior extent. More proximally, it crosses the internal jugular vein at the lateral process of the first cervical vertebra; here it is intimately related to the junctional or jugulodigastric lymph nodes, which are common to both the jugular and spinal accessory chains of lymph nodes. It is unsafe to preserve this nerve if these lymph nodes are involved. Initially, the nerve was preserved only when there were no clinically positive nodes in the neck, but there has been a recent move to preserve it as long as there are no clinically positive nodes directly adherent to the nerve.

Partial neck dissections remove those lymph nodes considered to be at greatest risk of harbouring metastasis from a given cancer. These procedures are generally used in the treatment of the clinically disease-free neck as a staging procedure to determine whether further therapy is indicated. The most commonly performed partial neck dissections are the lateral neck dissections (for cancers of the larynx and pharynx), the supraorohyoid neck dissection (for cancers of the oral cavity), and the posterolateral neck dissection (for skin cancers of the posterior scalp). Radiation therapy is effective in the treatment of occult neck disease. The greatest value of elective partial neck dissections is in the treatment of the clinically disease-free neck when the primary cancer can be effectively treated with surgery alone. In this instance, a partial neck dissection disclosing no pathological evidence of cervical metastases indicates that no further therapy is needed. The added morbidity of immediate radiation therapy can be avoided, such treatment being reserved for any future recurrences or new cancers.

After completing treatment, patients with squamous cell carcinomas of the head and neck should be seen monthly for the first year, every 2 months for the second year, every 3 months for the third year, every 6 months for the fourth year, and annually thereafter. A chest radiograph and, possibly, liver function studies should be obtained at 6 months and annually thereafter. If the patient has received radiation therapy to the neck, thyroid function should be reviewed regularly.

Carpenter RJ, De Santo LW, Devine LW, Taylor WF. Cancer of the hypopharynx. Arch Otolaryngol, 1976; 102: 716–21.

El Badawi SA, Goepfert H, Fletcher GH, Hrsn J, Oswald. Squamous cell carcinoma of the pyriform sinus. Head Neck Surg, 1983; 5: 508–13.

Harrison DFN, Thompson AE. Pharyngolaryngoesophagectomy with pharyngogastric anastomosis for cancer of the hypopharynx: review of 101 operations. Head Neck Surg, 1986; 8: 418–28.

Lingeman RE, Shellhamer RH. Surgical management of tumors of the neck. In: Thawley SE, Panje WR, Batsakis JG, Lindberg RD, eds. Comprehensive Management of Head and Neck Tumours. Philadelphia: WB Saunders Co, 1987: 1325–50.

Million RR, Cassisi NJ, eds. Management of Head and Neck Cancer: a Multidisciplinary Approach. Philadelphia: WB Saunders Co. 1984.

Million RR, Cassisi NJ. Larynx. In: Million RR, Cassisi NJ, eds. Management of Head and Neck Cancer: a Multidisciplinary Approach. Philadelphia: WB Saunders Co, 1984.

Ogura JH, Marks JE, Freeman RB. Results of conservation surgery for cancers of the supraglottis and pyriform sinus. Laryngoscope, 1983; 90: 591–600.

Silver CE. Surgery for Cancer of the Larynx and Related Structures. New York: Churchill Livingstone, 1981.

Silverberg E, Lubera JA. Cancer Statistics, 1988. Ca—A Cancer Journal for Clinicians, 1988; 38: 5–22.

Singer MI. Tracheoesophageal speech: vocal rehabilitation after laryngectomy. Laryngoscope, 1980; 93: 1454–65.

Thawley SE, Panje WR, Batsakis JG, Lindberg RD, eds. Comprehensive management of Head and Neck Tumours. Philadelphia: WB Saunders Co, 1987.

Wang CC. Radiation Therapy for Head and Neck Neoplasms. Littleton: John Wright, 1983.

Wetmore SJ, Key JM, Suen J. Laser therapy for T1 glottic carcinoma of the larynx. Arch Otol Head Neck Surg, 1986; 112: 853–5.