Predictors of successful clinical and laboratory outcomes in patients with primary sclerosing cholangitis undergoing endoscopic retrograde cholangiopancreatography.

Abstract

Endoscopic retrograde cholangiopancreatography (ERCP) in patients with primary sclerosing cholangitis (PSC) can be a challenging and sometimes gratifying opportunity for therapeutic intervention. Although there often appears to be initial radiological improvement after ERCP, the benefit as measured by serial estimations of subsequent liver enzymes is questionable. The fluctuating course of the inflammatory process makes the interpretation of serology even more difficult. To document and compare the liver profile and clinical status of patients before and after diagnostic and therapeutic ERCP; to determine predictors of clinical and laboratory success in patients with PSC; and to assess the complication rate of diagnostic and therapeutic ERCP in these patients. All patients with PSC who underwent ERCP at the authors' medical centres between January 6, 1987 and January 12, 1998 were identified using a computerized database. Presenting symptoms, liver enzymes (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase) and bilirubin were recorded before ERCP. Clinical success was defined as resolution of the presenting symptoms. Laboratory success was defined as improvement in two of three liver enzymes by at least 50%, or resolution of jaundice. One hundred four patients underwent 204 ERCPs of which 56 ERCPs were diagnostic. Clinical improvement was seen in 35% of the patients after diagnostic ERCP and in 70% after therapeutic procedures (chi 2=18.4, P=0.001). Laboratory improvement was seen in 35% of patients undergoing diagnostic ERCP and in 52% of the patients undergoing therapeutic ERCP (P=0.04). The reductions in liver enzymes were significant in both the diagnostic and therapeutic groups. Serum bilirubin level decreased significantly in the therapeutic ERCP group only. In a univariate analysis, patients with common bile duct strictures, any dominant stricture and those who underwent a therapeutic procedure were most likely to have clinical and laboratory improvement. In multivariable logistic regression, the presence of a dominant stricture, endoscopic therapy and high serum bilirubin were all independent predictors of a successful clinical outcome. There was no difference in total complication rates (18% versus 14%) when comparing the diagnostic and therapeutic ERCP groups. However, all seven severe complications occurred in the therapeutic ERCP group. First, in PSC, clinical and laboratory improvement is more common in patients undergoing therapeutic ERCP than diagnostic ERCP. Second, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase improve following both diagnostic and therapeutic ERCP, and should therefore not be relied upon to determine the success of the procedure. Third, bilirubin levels decreased in the therapeutic group but remained unchanged in the diagnostic group, suggesting that the serum bilirubin level may be a more sensitive indicator of successful therapeutic intervention than transaminases. Fourth, common bile duct strictures, dominant strictures and bilirubin levels are important variables in determining the success of an ERCP in PSC. Finally, complication rates after therapeutic ERCP are similar to those after diagnostic ERCP in PSC patients. However, severe complications occur more commonly in the therapeutic group.