Morphological changes in the choledochus during stenting for mechanical jaundice

Introduction. We have performed a comparative morphological analysis of the state of the choledochal wall when plastic and nitinol stent are implanted at different stages after stenting.Materials and methods. The study included 91 patients who underwent pancreatogastroduodenal resection for periampullary carcinoma at the Department of Hepatopancreatobiliary Surgery, Botkin Hospital from 2014 to 2020. Of these, 56 patients were previously stented using a plastic stent and 35 were stented using a nitinol stent. The histological structure of the choledochal wall was studied depending on the type of stent (plastic or nitinol) and the timing of its implantation (14-30 days, 31-60 days, 61 days and more).Results. When both types of stents are used, irreversible morphological changes develop in the ductus wall, but their nature is different. When plastic stents are used the changes occur in all layers of the wall and are characterized by mucosal atrophy and ductal fibrosis. With metal stents hyperplastic processes develop in the mucosa, the severity of which is proportional to the duration of the stent placement in the ductus lumen. Hyperplastic mucosa of the duct infiltrates the stent, narrows or completely obstructs the ductal lumen, creating additional opportunities for biofilm formation, while the muscular layer of the duct retains its structure.Conclusion. The functioning time of plastic stents is shorter than that of nitinol stents, the developing fibrotic-atrophic changes of the ductus wall when they are implanted have less influence on the ductus lumen and bile outflow than hyperplastic processes in nitinol stents, which makes reasonable the use of plastic stents preferable.