Effect of a novel pancreatic stent design on short-term pancreatic injury in a canine model

Background and Study Aims: Attempts to address the problem of injury to the pancreas by indwelling pancreatic stents are limited by our lack of knowledge of the pathogenesis of stent-induced injury and its relationship to stent morphology and the duration of stenting. The aim of our study was to evaluate pancreatic injury induced by 1 week of stenting with a 5F indwelling pancreatic stent of novel design, the "wing stent." Methods: Pancreatic stents (5F) were placed surgically in eight dogs; wing stents (WS-5F) were used in four dogs and conventional stents (CS-5F) in another four. Two dogs underwent duodenotomy without stent placement (controls). The pancreas was harvested for microscopy at 1 week. A pathologist who was unaware of the source of the specimens graded the pancreatic injury. Results: Although pancreatic injury was observed in both the CS-5F and WS-5F groups after 1 week of indwelling pancreatic stenting, it was considerably less severe in the WS-5F group compared with the CS-5F group (1.01 ± 0.10 vs. 1.63 ± 0.14, P < 0.01). All components of pancreatic injury were affected, with the most dramatic differences noted in inflammation, fibrosis, and edema. The differences were most marked in the stented segment (P < 0.001) and in the upstream segment of the pancreas (P < 0.05). Conclusions: Indwelling conventional pancreatic stents can cause significant pancreatic injury even when left in place for only 1 week. A wing design can significantly ameliorate stent-induced changes.