The effects of contrast agent and intraductal pressure changes on the development of pancreatitis in an ERCP model in rats

Objective Although there are various experimental pancreatic models in animals, only a few studies have evaluated how intraductal pressure and contrast agent affect the development of pancreatitis after endoscopic retrograde cholangiopancreatograpy (ERCP). Materials and methods The rats were randomly divided into seven groups (n = 8/group). The rats in all groups underwent laparotomy and their biliopancreatic ducts were cannulated transduodenally using a 24G catheter. In the control group, group 1, the biliopancreatic ducts of the rats were not infused with any fluid. The biliopancreatic ducts of the rats in groups 2, 3, and 4 were infused with 0.5 ml isotonic NaCl solution at 10, 2, and 50 mmHg, respectively. Groups 5, 6, and 7 were given 0.5 ml of 50% diluted contrast agent at 10, 25, and 50 mmHg, respectively. The serum amylase, aspartate aminotransferase (AST), lactic dehydrogenase (LDH), and C-reactive protein (CRP) were measured 24 h after the procedure. Pancreatic tissue was also evaluated histopathologically. Results Pancreatitis due to the contrast agent was noted when comparing the low pressure isotonic NaCl group and the low pressure contrast group (p < 0.05). Based on serum amylase and CRP values, there was a positive correlation between the severity and frequency of acute pancreatitis and pressure (p < 0.01). AST and LDH levels increased in all of the groups that underwent the procedure; however, no correlation was detected with increasing pressure or with the use of contrast agent (p > 0.05). Both pancreatic edema and the inflammatory cell infiltration score were elevated in isotonic NaCl and contrast group (p < 0.05); however, necrosis was not significantly changed (p > 0.05). Conclusion The results of this study suggest that the main mechanism for preventing pancreatitis after ERCP is to minimize trauma to the pancreatic canal, to cannulate the pancreas only when it is necessary, and to give contrast agent under low pressure when it is needed.