Pharyngo-cutaneous fistula development is a major complication associated with Laryngo-pharyngectomy. Most cases respond well to conservative treatment. In recurrent and chronic non-healing fistulas, the constant bathing by saliva of the altered tissue is a prime factor in retarding the progress of healing. Prevention of wound contamination with saliva is necessary. The Montgomery salivary bypass tube (MSBT, Photo 1) directs saliva into the distal esophagus and thus this procedure supports spontaneous closure of the fistula. We describe our experience with MSBT in a case of recurrent Pharygo-cutaneous fistula.
Case Background: A 66 years old male complained of saliva discharge from neck wound, 3 weeks after surgery. He had Stage 4 Squamous cell carcinoma Larynx; recently managed with Total Laryngectomy + partial pharyngectomy and Modified Neck Dissection. The patient was diagnosed as having Pharyngo-cutaneous fistula and he was managed conservatively. Patient was kept nil orally, given Ryle’s tube feedings, Intravenous antibiotics along with meticulous wound care and pressure dressings. The fistula closed temporarily but recurred immediately on resuming oral feeds.
Further conservative management failed to provide relief to patient, hence surgical repair was done. Patient underwent wound debridement with repair of fistula with radial forearm free flap plus pharyngeal dilation. Unfortunately patient had wound infection with multi-drug resistant pseudomonas, free flap failure and fistula recurred. Saliva leakage at wound site was found to be a significant risk factor detriment to wound healing and a decision was made to insert MSBT.
Technique of Insertion: We performed the procedure in LA but reckon that GA is also routinely used. Insertion is based on Seldinger technique (Diagram 1). First, using fiberoptic laryngoscope trans-nasally, a 1-0 silk thread was passed to oropharynx and brought out through the oral cavity. Secondly, trans-oral fiberoptic pharyngoscopy was done to identify and bypass the fistula site and a guide-wire was left in place. Thirdly, the previously inserted 1-0 silk thread was tied to the upper end of 10 mm MSBT. This was done to; later, secure the tube superiorly and prevent its down migration after insertion. Next, MSBT was rail-roaded over guide-wire into lower pharynx and upper esophagus. Position of MSBT was adjusted so that its upper funnel shaped end rested just below the Base of tongue. Lastly the position of MSBT was confirmed by doing a check endoscopy. 1-0 silk thread was taped to left cheek to secure the tube.
Outcome: Before MSBT insertion, patient had Pharyngo-cutaneous fistula with skin defect roughly measuring 8×5 cm, purulent discharge and continuous saliva leak. Within a month’s time; the skin defect closed completely, wound infection subsided and there is no fresh saliva leakage. Most importantly, the patient is able to accept soft diet through MSBT.
Discussion: MSBT (Boston Medical Products, Westborough, MA) was introduced in 1978. The tubes are made of medical grade silicone which is soft and flexible but still firm enough to maintain luminal patency. It is available in seven sizes varying from 8 to 20 mm in outside diameter (12–14 mm tubes allow the patient to swallow a semisolid diet). The length is constant with 191 mm. The superior end of the tube is funnel-shaped to facilitate the collection of saliva and maintain proper positioning.
The tube is indicated in management of strictures of the pharynx or cervical esophagus, Tracheo-esophageal fistulas and Pharyngo-cutaneous fistulas. High Cost of tube, Rs 30,000, has prevented its widespread use in all cases, in Indian setting. However, in recurrent Pharyngo-cutaneous fistulas its utility is unmatched. Its biggest advantage is it that it allows oral feedings. Being able to eat and drink without the need for intravenous supplementation or nasogastric or gastrostomy tube feeding in general greatly improves the patient’s quality of life. There are no major complications associated with its usage although some of the patients might get a foreign body sensation.
Conclusion; In the management of recurrent Pharyngo-cutaneous fistulas, MSBT offers a safe and reliable option that stops salivary wound contamination and allows faster wound healing.
