Pharyngoesophageal Stenosis (post-treatment)
Patients who undergo treatment for head and neck malignancies often undergo a combination of surgery, radiation and chemotherapy. Normal tissue in the throat (pharynx and esophagus) is often damaged by the toxic effects of radiation to the tissue lining those regions. The unwanted side effects of radiation therapy are often more severe when chemotherapy is added. As a result, patients may experience secondary functional problems even after successful treatment of cancer.
The development of post-treatment swallowing difficulties (dysphagia) may lead to the need for the patient to receive his or her nutrition through a gastrostomy feeding tube placed directly into the stomach. Other problems that may lead to swallowing difficulties secondary to radiation include the loss of muscle strength of the swallowing tube and the lack of coordination in the steps of successful swallowing (deglutition) due to deconditioning of this region.
The narrowing of the caliber of the pharynx and esophagus is one of the most significant challenges that patients face, preventing the normal flow of food and liquid into the thoracic esophagus. The narrowing may be partial or complete, often reflected by whether the patient is able to swallow his or her own secretions or any liquids. In the most severe form of this condition, patients are unable to tolerate their own saliva and require either a suction apparatus or repetitive expectoration in order to clear their throat. The development of a narrowing may also affect the voice box, as well as the area above the vocal cords, such that patients who are so afflicted may require a tracheostomy to comfortably breathe. The development of a narrowing requires a careful assessment through the use of a modified barium swallow that is performed by an experienced speech and swallowing specialist. In addition, endoscopy may provide a more definitive assessment of the narrowed segment as well as an appreciation of the functional status of the vocal cords.
Options for treatment include dilation with progressive enlargement of the narrowed portion of the esophagus. In those patients who have a complete or near-complete obstruction, a special technique known as the rendezvous procedure is required. This specialized technique is performed with an endoscope passed in a retrograde fashion through the gastrostomy tube site in the stomach, as well an antegrade endoscopy through the mouth. Through this technique the narrowed segment is approached from opposing directions. If a complete obstruction is encountered then a guidewire is passed across the obstructed segment and then progressive dilation is performed through that segment. One of the risks associated with the use of dilation procedures is tissue damage to areas already compromised from radiation exposure. As a result, patients may need to undergo secondary dilation procedures. There is always the possibility that dilation may lead to a worsening of the condition. As with any technique that successfully reestablishes the opening between the oral cavity and stomach, it can never be predicted with certainty that the patient will regain normal swallowing, eliminating the necessity for the gastrostomy tube. Unfortunately there is no good way to determine the patient’s ability to swallow before opening up the stenotic segment.
Reconstructive surgical techniques have been developed that have been shown to successfully open the narrowed segment by importing healthy, new, non-radiated tissue from other parts of the body that augment the lining of the narrowed region and bypass the obstructed segment. These techniques have been developed for patients who have had failed dilation attempts, who have had attempted dilation that led to a perforation or who have been determined not to be suitable candidates for dilation. The type of reconstructive technique and the approach depends upon the extent of the narrowing and the particular details of each patient.
Despite significant advancements in the management of postoperative swallowing difficulties, some patients have such severe dysfunction that dilation or reconstruction may not result in successful swallowing or prevent the development of aspiration leading to pulmonary infection. In these patients, it’s more appropriate to consider more definitive surgical procedures that involve the removal of the larynx, combined with reconstruction of the esophagus. Although a laryngectomy is irreversible and will lead to a permanent opening in the neck for breathing, patients can anticipate the resumption of swallowing that will eliminate the need for a feeding tube, with the ability to speak restored through a variety of rehabilitative techniques.
The careful assessment and implementation of a rehabilitative program for post radiation patients requires a team of experienced head and neck surgeons, gastroenterologists, and speech and swallowing specialists.