Post-ERCP pancreatitis: patient and technique-related risk factors.

Reported rates of pancreatitis after ERCP and sphincterotomy range from less than one percent to 40 percent, but rates of 5 percent or more are typical [1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23]. Variations in reported rates of pancreatitis relate to many factors including the definition used, the thoroughness of follow up [24], and to patient and technique-related risk factors. In the consensus classification [1], pancreatitis is defined as clinical syndrome consistent with pancreatitis (i.e. new or worsened abdominal pain) with an amylase at least three times normal at more than 24 hours after the procedure, and requiring more than one night of hospitalization (Table 1). Some events are difficult to classify in the consensus definition, such as for patients with post-procedural abdominal pain and elevation of amylase to just under 3 times normal, or those with dramatic amylase elevations but minimal symptoms that are not clearly suggestive of clinical pancreatitis. There are many potential mechanisms of injury to the pancreas during ERCP and endoscopic sphincterotomy: mechanical, chemical, hydrostatic, enzymatic, microbiologic, and thermal. Although the relative contribution of these mechanisms to post-ERCP is not known, recent studies have used multivariate analyses to identify the clinical patient and procedure-related factors that are independently associated with pancreatitis [3, 16, 18, 19, 20, 21, 22]. However, even multivariate analyses can sometimes be misleading if key variables are not assessed, thereby making surrogate associated markers appear significant instead [25].