Are large side holes associated with reduced rates of pancreatic stent occlusion? Results of a prospective study.

CONTEXT Pancreatic stents are frequently clogged at the time of removal. There is limited data regarding the factors associated with stent occlusion. OBJECTIVES To estimate the frequency of stent occlusion at the time of removal, to study the accuracy of endoscopic prediction of occlusion, and to determine the factors associated with clogged pancreatic stents. SETTING Consecutive patients at 4 academic medical centers undergoing removal of a previously placed pancreatic stent were prospectively enrolled. PATIENTS A total of 68 patients were enrolled between August 2007 and July 2008. INTERVENTIONS Following removal, stent occlusion was immediately assessed by complete lack of water flow from the duodenal end and side holes of the stent. MAIN OUTCOME MEASURE Survival analysis was performed using a Kaplan-Meier and Cox Regression model. RESULTS Indications for stent placement included chronic pancreatitis (n=23), pancreatic duct leak (n=7), prevention of post-ERCP pancreatitis (n=28), pseudocyst drainage (n=1), pancreas divisum (n=8), and pancreatic duct stricture without chronic pancreatitis (n=1). Standard Geenen (Cook Endoscopy, Winston-Salem, NC, USA) pancreatic stents were placed in 53 patients (77.9%). The majority of stents (42, 61.8%) were completely occluded at the time of removal. Median time to stent occlusion was 35 days (95% CI: 30-40 days). Stent type, diameter, length, number of small side holes, and indication for placement were not predictive of subsequent stent occlusion. However, stents with at least 4 large, flange-associated side holes were 54% less likely to be clogged upon removal (HR=0.46, P=0.029). CONCLUSIONS Pancreatic stents are mostly occluded as early as 1 month after insertion. Larger side holes may prevent stents within the pancreas from becoming clogged.