Alterations in pancreatic ductal morphology following polyethylene pancreatic stent therapy

Polyethylene stents placed in the main pancreatic duct induce morphologic alterations that may resemble chronic pancreatitis.

We reviewed the sequential pancreatograms of stented patients who had long-term follow-up after stent removal.

Forty patients (66%) had a normal baseline pancreatogram, whereas 21 (34%) showed changes of chronic pancreatitis. In 49 of 61 patients (80.3%), one or more had new morphologic changes immediately after stent withdrawal graded as mild (69%), moderate (29%), or severe (2%). Changes included ductal irregularity (49%), narrowing (35.5%), and side branch change (15.5%). Sixteen of the 21 patients (76.1%) with an abnormal baseline pancreatogram had worsening of the baseline abnormality or additional changes while stented, whereas 33 of 40 (82.5%) with a normal baseline developed new morphologic changes. Correlation of stent-induced changes with stent size, length, patency at removal, and duration of stenting failed to show an association. Twenty-five patients with stent-induced changes had a follow-up pancreatogram at a mean of 192 days (10 to 740) after stent removal. There was complete resolution of the changes in 64%, partial resolution in 32%, and no improvement in 5%.

Morphologic changes induced by polyethylene pancreatic duct stents occurred in 80% of patients. More than one third of these changes did not resolve during the follow-up period. Because of concern over stent-induced fibrosis, the use of pancreatic stents should remain largely experimental.