Diagnosis and management of pyriform sinus fistula: experience in 48 cases.

PURPOSE: Pyriform sinus fistula (PSF) is often overlooked, and presents diagnostic and management challenge. The aim of this study was to highlight the value of intraoperative endoscopy-assisted intubation or methylene blue injection through the internal opening as a guide in searching for the fistula. METHODS: The charts of 48 patients diagnosed with PSF during January 1990 until January 2013 were retrospectively reviewed. The records were analyzed for sex, side of lesion, age at onset/diagnosis, initial presentations, diagnostic methods, microbiologic cultures, pathologic findings, treatments and outcomes. RESULTS: There were 22 males and 26 females, with a median age at onset and diagnosis of 2 years (range, 8 months to 9 years) and 4 years (range, 12 months to 13 years), respectively. The lesions were predominantly left sided (93.7%). The most common presentation was neck abscess (62.5%). Other presentations were acute suppurative thyroiditis/thyroid abscess (7), neck mass with or without dyspnea (9), and thyroid nodule (2). Barium esophagography showed the sinus tract in 100% cases. The positive predictive value of other modalities was oral-contrast CT 88.9%, intravenous contrast-enhanced CT 53.8%, noncontrast CT 33.3%, and sonography 7.9%. Thyroid function were reported normal in most tested cases (14/15, 93.3%). The fistula tract was lined with pseudostratified squamous epithelium or ciliated columnar epithelium, often associated with inflammatory changes. Bacteria cultured from the discharge were found to be oral flora. Partial thyroidectomy was operated on 11 cases. Two patients (2/8, 25%) who underwent open surgery without endoscopic assistance exhibited recurrence, while no recurrence was noted in children with the help of intraoperative endoscopy. Postoperative results were good in majority (93.7%). CONCLUSION: PSF should be considered in any children with repeated neck or thyroid infection/mass. The combination of barium esophagography, CT scan and ultrasound is useful to establish the diagnosis. Intraoperative endoscopy-assisted intubation or methylene blue injection through the internal opening as a guide can facilitate identification of the tract during dissection.