Complications of endoscopic sphincterotomy: Can heparin prevent acute pancreatitis after ERCP?

Background. An exploratory analysis of a prospective study of risk factors for acute pancreatitis after ERCP combined with endoscopic sphincterotomy showed that the frequency of acute pancreatitis was lower in patients who received heparin compared with patients not treated with heparin. The study was continued to further analyze the effect of heparin on the frequency of acute pancreatitis. Methods: Potential risk factors for acute pancreatitis and outcomes were evaluated prospectively for all ERCP procedures with endoscopic sphincterotomy performed between September 1994 and December 1998. The results were analyzed by univariate and multivariate methods to determine risk factors for complications. Heparin was administered to 32.9% of the patients (heparin group [HEP group], n = 268) for various clinical reasons (low-molecular-weight heparin, n = 208, unfractionated heparin n = 60). A group of 547 patients who did not receive heparin served as control patients (CON group). Results: Eight hundred fifteen patients underwent ERCP with endoscopic sphincterotomy; acute pancreatitis occurred in 6.4% (n = 52). The frequency of acute pancreatitis was significantly lower in the HEP group versus the CON group in the final multivariate model, which included significant risk factors for acute pancreatitis (HEP group: 3.4%, 9/268 vs. CON group: 7.9%, 43/547; p = 0.005). HEP did not increase the risk of hemorrhage (HEP group: 1.1%, 3/268, 2 severe, none fatal vs. CON group: 2.0%,11/547, 3 severe, 2 fatal). HEP (p = 0.005; OR 0.3: 95% Cl [0.16, 0.73]) and the number of risk factors present (p = 0.0001; OR 2.5: 95% Cl [1.80, 3.50]) influenced the frequency of acute pancreatitis independently. Conclusions: Heparin was significantly associated with an extremely low frequency of post-ERCP pancreatitis without increasing the risk of hemorrhage after encloscopic sphincterotomy. Because this effect could not be attributed to other known or suspected confounders, our conclusion was that heparin administration before ERCP reduces the risk of pancreatitis.