Histopathological features in esophageal atresia with lower esotracheal fistula

Abstract

Introduction. Despite the success obtained in reconstructive operations of esophageal atresia, a major frequency of complications documented in the postoperative period has been still persisting, including dysphagia, gastroesophageal reflux, esophageal peristaltic disorders etc. Aim to analize the spectrum of morphopathological changes revealed in cases of esophageal atresia with lower esophageal-tracheal fistula and to establish the role in the development and evolution of postoperative complications. Methods: Histopathological study was conducted on 21 patients. It included autopsy materials performed on unoperated specimens from 8 newborns with esophageal atresia and lower esophageal-tracheal fistula, and in 13 cases from operated newborns. Serial sections both of the proximal segment (sealed/blunt) of the esophagus and of the distal segment to the fistula were made. Results: On the level of the atretic segment of the esophagus (sealed/blunt), the esophageal wall was characterized by a well differentiated structure, the proper muscular coat of the submucosa being frequently hypertrophied. The submucosa exhibited a dense fibrillar connective tissue with predominance of collagen fibers, with their emphasis towards the atretic end. Reduction of autonomic and myenteric nervous network was found in different ratio in the muscular coats (circular and longitudinal layer). The muscular coat located focally or regionally was often substituted by plates of collagenized and mesenchymal connective tissue. The distal fistulated segment of the esophagus was characterized by advanced dysplastic changes, absence of muscular coats or its reduction, with presence of chaotic hypotrophic or hypertrophic fibers or bundles, arranged in a mass of connective tissue. Compared with the proximal segment, including the region of the fistulous orifice, in some cases presence of glandular structures of pseudoadenomatous and cystic appearance was observed. There could be observed ganglioneuronal structures with vascular and granular dystrophy on the level of fibro-muscular dysplastic processes in areas which showed presence of nervous myenteric network. Conclusion: The results of this study allowed to confm obvious structural pathological changes that may significantly influence regenerative-reparative processes and postoperative esophageal motility after reconstructive operations.