A case series study of therapeutic implications of type IIIb4: a rare variant of esophageal atresia and distal tracheoesophageal fistula.

BACKGROUND: A wide spectrum of variations can occur in type IIIb esophageal atresia and distal tracheoesophageal fistula [EA-TEF] (Kluth D. Atlas of esophageal atresia. J Pediatr Surg 1976; 11 (6):901-19). The aim of this study was to evaluate the variant anatomy of subtype IIIb4 EA-TEF and its therapeutic implications. METHODS: We performed a retrospective review of 4 patients of this variant subtype within a series of 259 esophageal atresias, managed over a study period of three years, at our institution. The diagnosis was made at thoracotomy. The overlapping upper and lower esophageal pouches, initially, gave a false impression of esophageal continuity. The long TEF coursed parallel in proximity to the upper pouch (UP) and the trachea needing meticulous dissection. The TEF measured 8-10mm in diameter and was ligated and divided high on the trachea near the thoracic inlet. The patients were followed up by a contrast swallow, radioactive technetium-99m- sulfur colloid scan, echocardiography and bronchoscopy (if indicated). RESULTS: The mean birth weight and gestational age was 2250 g and 38 weeks respectively. The mean follow up was eighteen months (range 5-42 months). An associated anorectal malformation was present in two patients while none had associated congenital heart disease. The Waterston grading was A and B in one patient each and C in two patients. All the patients had muscular UP extending up-to the level of arch of azygous vein (T(3-4)). The lower esophageal pouch (LP) and the fistula extended high, near the thoracic inlet. Tracheal injury occurred in one patient, with thin LP, warranting postoperative elective ventilation. A postoperative barium swallow did not reveal anastomotic leak or stricture in any patient. Follow-up barium swallow showed long LP extending high up in the chest, up to clavicles in all four patients and redundancy of UP in case 1. Severe gastroesophageal reflux was present in two patients. Bronchoscopy revealed tracheomalacia in case 1. Three patients were thriving well at the last follow-up. One patient died at five months of age due to aspiration pneumonia. CONCLUSIONS: The knowledge of diagnostic and therapeutic implications of the variant subtype IIIb4 EA-TEF should be in the armamentarium of the treating surgeon to reduce pitfalls in its management.