Intrapancreatic dexamethasone does not prevent sphincterotomy-induced pancreatitis in a canine model

Acute pancreatitis is a common and potentially serious complication of ERCP. While the exact pathogenesis of ERCP-induced pancreatitis is unknown, retrospective data has suggested that the use of steroids before ERCP may reduce the incidence of pancreatitis. On the other hand, steroids have also been implicated in the pathogenesis of acute pancreatitis in some patients. Therefore, the use of steroids for prophylaxis against ERCP-induce pancreatitis has the potential for both beneficial and harmful effects. Methods. We studied the effects of directly administering steroids to the pancreas just before the inciting injury in a newly developed dog model of sphincterotomy-induced pancreatitis. 8 semi-conditioned mongrel dogs underwent ERCP after sedation with acepromazine and pentobarbital. After free cannulation of the minor papilla by a blinded endoscopist, dogs were randomized into two groups. In group 1 (placebo) 4.5 ml of contrast + 0.5 ml saline was injected into the main pancreatic duct under constant pressure until acinarization was achieved. Animals in group 2 were injected identically with 4.5 ml of contrast + 0.5 ml of dexamethasone (containing 5 mg of the steroid). Thereafter, all dogs underwent papillotomy of both the minor and major papillae. 24 hours later the pancreas were harvested and examined by a blinded pathologist. Pancreatitis was graded histologically on a scale of 0-4 for edema, polymorphonuclear cell infiltrate, intraparenchymal hemorrhage, parenchymal necrosis and vacuolization of acinar cells. Results A significant elevation in serum amylase was seen 1 hour after sphincterotomy in the dexamethasone group (852 vs 596;P=0.01) but not in the placebo group. However, there were no significant differences in total inflammatory scores between the two groups at 24 hours (7 vs 12;P=0.34). Conclusions. Intrapancreatic instillation of dexamethasone does not appear to be effective in preventing sphincterotomy induced pancreatitis and has the potential for worsening hyperamylasemia.