Hypopharyngeal pharyngoplasty for the management of piriform fossa sinus

Abstract

Piriform fossa sinus (PFS) is a rare congenital anomaly of the third or fourth branchial pouch. Failure of the pharyngobranchial duct to degenerate causes a persistant connection between the piriform sinus and the lateral neck.1 Presentation age ranges from infancy to adulthood and may occur as a neck mass, thyroid abscess, recurrent deep space neck infection, or with iatrogenic fistula formation.2, 3 Of these anomalies 97% are left sided.1, 2, 4 The current standard for management of these lesions is complete surgical resection of the fistula.3 Transcervical resection can be complicated by inflammation, obliteration of normal tissue planes, and failure to identify the sinus tract. Complete surgical resection, therefore, can be difficult and incomplete, leading to further recurrence of infections. Here we present a new surgical approach for the management of PFS termed hypopharyngeal pharyngoplasty, describing the technique and reporting preliminary outcomes in three cases. A 41-year-old female presented with a 31-year history of recurrent neck infections. At 10 years of age she had a thyroid abscess treated with an incision and drainage. A thyroid biopsy at that time was consistant with inflammatory changes. Twelve years later the infection recurred with neck swelling, dysphagia, and otalgia again requiring incision and drainage. She continued to have frequent recurrent neck infections requiring intervention. At current presentation, her history was notable for multiple surgical interventions including seven incision and drainages, a direct laryngoscopy, and left hemithyroidectomy. During one of her prior surgeries vegetable matter had been retreived from the abscess cavity. A barium esophagram revealed an extraluminal focal fluid collection caudal to the left piriform sinus (Fig. 1). She underwent a left neck exploration with strap muscle repair of the piriform sinus fistula, but the infection recurred 7 months later. She then underwent hypopharyngeal pharyngoplasty with intraoperative visualization of a large piriform sinus opening (Fig. 2). She has had no recurrence in 7 months to date. Barium extravasation from the left piriform sinus. Large piriform sinus opening visualized during surgery. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.] A 39-year-old female presented with acute left neck swelling. Ultrasound revealed a fluid collection lateral to the left thyroid, and cultures from a fine needle aspiration were consistant with oral flora. A computed tomography (CT) scan demonstrated air in an abscess cavity in the left thyroid bed. She improved with antibiotic therapy and her barium esophagram was normal; however, her neck infection recurred soon thereafter. Her past surgical history was significant for a thyroglossal duct cyst excision at ages 7 and 10; however, these surgeries in retrospect were likely the initial manifestation of the piriform sinus fistula. After a period of quiescence she underwent hypopharyngeal pharyngoplasty with left hemithyroidectomy. She has had no evidence of recurrence for 9 months. A 17-year-old male presented with a history of recurrent left neck infection. His initial presentation was at 6 years of age when he was diagnosed with a suspected congenital branchial anomaly and underwent transcervial excision. An opening in the left piriform sinus was subsequently documented on operative laryngopharyngoscopy and was cauterized on one occasion. Recurrent left neck abscesses additionally resulted in four subsequent transcervical procedures, the most recent of which had included a left hemithyroidectomy and a sternocleidomastoid muscle flap. Despite these latter procedures, a persistent sinus tract was identified on barium swallow study necessitating gastrostomy tube placement for enteral rather than oral alimentation. A hypopharyngeal pharyngoplasty was subsequently performed. He is 8 months postoperative without recurrence to date. Under general anesthesia a horizontal skin incision is made at the level of the inferior border of the thyroid cartilage, or alternatively a standard thyroidectomy incision can be utilized if undergoing concurrent thryoidectomy. Superior and inferior subplatysmal flaps are raised to provide adequate exposure, and the strap muscles on the designated side are retracted or divided to expose the thyroid cartilage. After the resection of the left thyroid gland in standard fashion with identification and preservation of the recurrent laryngeal nerve and superior laryngeal nerve, attention is turned to the thyroid lamina. The larynx is rotated medially and the inferior constrictor muscle is dissected off of the posterior aspect of the thyroid cartilage using electrocautery and blunt dissection. The piriform mucosa is swept in a cephalad direction off of the posterior cricoarytenoid muscle. The piriform sinus is delineated along its medial, lateral, and inferior margins until it can be pulled away from the posterior larynx. The piriform sinus apex is examined for the fistula, grasped with a Babcock retractor and pulled through an endoscopic stapling device (Endo-GIA stapler; Auto Suture Company, United States Surgical Corp., Norwalk, CT), which is placed on the cephalad limit of the sinus (Fig. 3). This may be performed twice to fully resect the piriform sinus. After hemostasis is obtained, the strap muscles are reapproximated, a penrose drain is placed in the wound, and the platysma and skin layers are closed in the standard manner. In the immediate postoperative setting, patients begin with a soft diet and progress to regular diet over the course of 2 weeks. Patients are not placed nil per os after the procedure. Postoperative barium swallow is not routinely performed. Stapler placed across the piriform apex. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.] Three patients presented to our institution, a tertiary referral center, with PFS in 2008. All three patients presented with a history of recurrent neck abscesses despite multiple previous operative interventions. The diagnosis of PFS was made based on the patient history, culture of oral flora from neck abscesses, and/or fistula confirmation on modified barium swallow study. Two patients had barium swallow studies with demonstration of the fistula tract. One patient had a negative barium swallow, but air in an abscess cavity on CT imaging and oral flora cultured from the neck abscess rendering the diagnosis. In one case, the piriform sinus opening was visually identified during the procedure (Fig. 2). No complications occurred and no patients required a nasogastric tube after hypopharyngeal pharyngoplasty. All patients had normal vocal fold mobility and preservation of the recurrent laryngeal nerve. The duration of postoperative follow-up was 7 to 9 months. To date, there have been no recurrences. The difference between third and fourth branchial anomalies is based on embryology with the third branchial anomaly passing superiorly to the superior laryngeal nerve and the fourth branchial anomaly passing inferiorly to the superior laryngeal, looping around the subclavian artery on the right and the aortic arch on the left.4 Some authors do not distinguish between third and fourth branchial pouch anomolies and classify all as PFS. We also prefer to use the term PFS because both anomalies open into the piriform sinus and the theoretical course of the sinus tract in the neck and in the mediastinum cannot be definitively identified. The diagnosis of these anomalies is commonly delayed. Air in an abscess cavity adjacent to the larynx, a barium swallow with evidence of fistula from the piriform sinus, or oral flora cultured from a thyroid abscess is diagnostic. Barium swallow studies may only diagnose the sinus anomaly 80% of the time.1 Two of our patients had barium swallow studies that confirmed the diagnosis. One patient did not have evidence of a sinus on barium swallow. Clinicians must have a high index of suspicion of PFS when a patient presents with a thyroid abcess or recurrent neck infections, especially on the left. The current surgical management of these anomalies is controversial. Most authors recommend external surgical approach; complete excision of the fistula tract with closure of the piriform sinus, and hemithyroidectomy.5-8 During transcervical dissection, the superior and recurrent laryngeal nerves are at risk, especially after multiple infections or in a previously operated field.6, 8 Despite use of dyes or catheters, the exact location of the fistula is not always evident at the time of operation, which may account for the frequent recurrences after attempted transcervical excision. To avoid an external dissection, some authors have suggested endoscopic obliteration of the internal opening of the fistula with trichloroacetic acid, fibrin glue, or an insulated electrocautery probe.9-12 The endoscopic approach minimizes the risk of injury to the superior and recurrent laryngeal nerves, avoids external scars, and minimizes hospitalization. However, the piriform sinus mucosa theorectically can be injured from these mechanisms leading to recurrent piriform sinus openings. Imperative for the endoscopic approach to be successful, the opening in the piriform sinus must be visualized, and this is not always possible. Only one of our patients had an opening in the piriform fossa visible on the direct laryngoscopy. Hypopharyngeal pharyngoplasty was first described by Mok et al. as a new procedure to improve swallow function in the paralyzed pharnx.13 The procedure is designed to remove redundant mucosa and decrease pooling of secretions in the hypopharynx. We adopted this procedure to surgically remove the opening of the branchial sinus in the piriform fossa. This technique has been successfully used in a series of 16 patients with dysphagia associated with unilateral recurrent laryngeal nerve injury (without any complications from the pharyngoplasty). The procedure appears to have low morbidity as there have been no complications in our experience or Mok's published series. By means of an endostapler, the pharyngeal opening of the fistula is closed with a water-tight seal preventing recurrences. Detection of the sinus tract with catheters, injection of dyes, or visualization with direct laryngoscopy is unnecessary as the technique provides near complete resection of the ipsilateral piriform sinus mucosa. This procedure is easily performed in combination with hemithyroidectomy. Although a subject of controversy, we recommend hemithyroidectomy in addition to hypopharyngeal pharyngoplasty. The fistula tract is in close association with the thyroid and removal of the hemithyroid can facilitate excision of the fistula tract and decrease infection recurrence. Definitive surgical repair should be performed only after a period of quiescence. Acute infections should be managed with antibiotics, needle aspiration, or incision and drainage as appropriate.14 Careful preservation of the recurrent laryngeal nerve and superior laryngeal nerve is necessary and can be facilitated with intraoperative nerve monitoring. Hypopharyngeal pharyngoplasty is a definitive procedure for PFS. Hypophayrngeal pharyngoplasty for third and fourth branchial anomalies requires limited hospitalization, no need to stop postoperative oral feeding, and minimizes the risk for superior and recurrent laryngeal nerve injury with appropriate visualization. This new indication for this technique appears promising; however, further long-term data is needed to determine the effectiveness of the procedure in management of third and fourth branchial anomalies. The authors acknowledge Peter J. Mazzaglia, MD and Derrick T. Lin, MD for their data contributions to this article.