Rate of bilirubin regression after stenting in malignant biliary obstruction for the initiation of chemotherapy: How soon should we repeat endoscopic retrograde cholangiopancreatography?

BACKGROUND. This study was conducted to evaluate the rate of regression of bilirubin after stent placement for malignant biliary obstruction. METHODS. Records were reviewed from October 2002 to September 2005 for patients who underwent endoscopic retrograde cholangiopancreatography with stent placement. The time to achieve a bilirubin level ≤2 mg/dL was the primary endpoint because this is the level required by most chemotherapy protocols. Patient variables included type of cancer, liver metastasis, recent chemotherapy, baseline creatinine, and international normalized ratio (INR). Stent variables included type, dimension, stricture location, and sphincterotomy. RESULTS. In total, 156 patients were included in the analysis: Ninety-three patients achieved a poststent bilirubin level ≤2 mg/dL, 29 patients failed because of stent failure, and 34 patients failed because of inadequate follow-up. The time required for 80% of patients to achieve normalization was more than doubled in those who had prestent bilirubin levels ≥10 mg/dL (6 weeks) compared with those who had prestent bilirubin levels <10 mg/dL (3 weeks). The following variables were identified as statistically significant: prestent bilirubin level, stricture location, liver metastasis, and INR. The cancer type, recent chemotherapy, stent type and diameter, and sphincterotomy were not statistically significant variables. CONCLUSIONS. The rate of bilirubin normalization after biliary stenting was highly dependent on the prestent bilirubin level. Endoscopic intervention should be considered in patients who fail to achieve adequate normalization of serum bilirubin in 6 weeks if prestent bilirubin level was ≥10 mg/dL and in 3 weeks if their prestent bilirubin level was <10 mg/dL. Independent variables, such as diffuse liver metastases, stricture outside the common bile duct, and elevated INR had predictive value for bilirubin normalization.