The modified Siegel stent vs. the modified geenen stent; A study of stent migration and pancreatic ductal changes with flapless pancreatic stents

We had previously studied the modified Geenen pancreatic stent (straight stent with external flaps only) in comparison with the Siegel C-loop stent, which has an internal flap. In that short term study, only patients with the Siegel stent had developed ductal stricturing, so we concluded that elimination of the flap may make short-term stenting safer. We studied this hypothesis with a new randomized prospective study. Methods: Patients undergoing pancreatic stenting alternatively received either a modified Geenen or Siegel stent (Wilson-Cook Inc, Winston-Salem), where both stents's internal flaps were removed prior to their placement. Stents were generally removed after 2-3 weeks and pancreatography was repeated. Pre- and post-stent studies were compared to determine the presence of stricturing, and stent migration was also recorded. Results: Between 12/9/96 and 11/6/97, 48 patients had pancreatic stents placed. Of these, 28 had follow-up pancreatograms and so could be included in this study. 14 patients had Geenen stents and 14 had Siegel stents. Stricturing occurred in 5 patients with the Geenen (36%) and 3 patients with the Siegel (21%) (NS) over a mean length of time of 21.2 days and 16.7 days respectively (NS). Out-migration occurred with 3 Geenen stents and 4 Siegel stents (NS). There were no inwards migrations of either stent. Conclusions: Even short term stenting of the pancreatic duct can lead to a high rate of ductal changes. The removal of the internal flaps does not seem to eliminate this problem, hut does seem to avoid the problem of inwards migration of pancreatic stents.