A Comparative Scanning Electron Microscopic Study of Biliary and Pancreatic Stents

Abstract

Little is known about the similarities and differences in the clogging process of biliary and pancreatic stents. The aim of the study was to elucidate this process using scanning electron microscopy. Scanning electron microscopy was performed in a consecutive series of 18 biliary and 10 pancreatic endoprostheses. The indication for stenting in the 18 patients (13 men, 5 women) with biliary stents was malignancy (n = 11), benign bile duct stenosis (n = 5), and biliary obstruction by bile duct stones (n = 2). The indication for stenting in the 10 patients (8 men, 2 women) with pancreatic stents was chronic pancreatitis with or without stenosis of the pancreatic duct. The scanning electron microscopy study revealed a quite uniform pattern of the clogging material in biliary and pancreatic stents. The clogging material seemed to adhere to the inner stent surface by numerous tiny threads. The clogging material itself was also stabilized by tiny threads. The occurrence of the tiny threads constitutes the central point in the clogging process in biliary and pancreatic stents. Inhibiting the formation of these threads or at least preventing adhesion to the inner stent surface might be the best option to improve stent patency.