ANALYSIS OF OCCLUDED PANCREATIC STENTS AND JUICES IN PATIENTS WITH CHRONIC-PANCREATITIS

Background: Pancreatic stents may occlude with time, and there is litt le information available on the nature of the clogging process. Method s: We analysed the contents of occluded pancreatic polyethylene stents in nine patients with chronic pancreatitis. In the same patients, the protein patterns in the corresponding pancreatic juices were analysed . The stents had been in place for a mean of 9 weeks (range 2 to 17). Results: All stents were occluded at both ends, especially around side holes, with thick creamy-white precipitate. The average dry weight of occluding debris was 3 mg per 3.25 cm 10F stent. Total protein conten t was 50% (SD 16.3) and total calcium 0.8% of dry weight (SD 0.6). Lig ht microscopy showed that proteinaceous material completely filled the stent lumen. Yeasts and plant material were seen in two stents. A var iable number of bacteria of mixed species, sometimes in clumps, were p atchily scattered in the protein matrix. Cultures of stent contents gr ew several species of Gram-positive and negative bacteria. Scanning an d transmission electron microscopy showed an amorphous protein matrix in all stents, arranged as a network in some areas, but in layers in o ther areas. Sodium dodecylsulfate polyacrimide gel electrophoresis sho wed that protein patterns of stent contents were remarkably different from the protein patterns of the juice samples of the same patient. A 66 kD band, identified as albumin, appeared in the protein patterns of stent content, whereas it was lacking in most juice samples. Conclusi ons: Adherence of protein, especially album in, plays an important rol e in the process of pancreatic stent clogging. Other factors, such as bacteria, refluxed duodenal contents, and calcium seem to be of less i mportance.