ABSTRACT
Biliary and pancreatic stents are effective tools in the management of obstructive jaundice (both malignant and benign), pancreatic pseudocyst drainage, and as treatment for biliary and pancreatic fistulae. Unfortunately, stents may become blocked and require replacement in a number of patients. In the present study a blocked stent from a patient with transpapillary drainage of pancreatic pseudocyst and another from a patient with obstructive jaundice resulting from cancer of the head of the pancreas associated with Mirizzi syndrome were characterized by electron microscopy. Stent blockage was diagnosed by a pressure test and stent cultures were performed. Electron microscopy of the blocked stents revealed the sludge to consist of microcolonies of bacteria mixed with amorphous material, and cultures of both stents were positive for Klebsiella sp and E. coli.