Predictors of Recurrent Biliary Obstruction Following Percutaneous Uncovered Metal Stent Insertion in Patients with Distal Malignant Biliary Obstruction: An Analysis Using a Competing Risk Model.

OBJECTIVE: To evaluate predictive factors of recurrent biliary obstruction (RBO) following percutaneous uncovered metal stent placement for unresectable distal malignant biliary obstruction (MBO) by using a competing risk model.

MATERIALS AND METHODS: Between March 2012 and March 2016, 119 patients underwent percutaneous uncovered metal stent placement with distal MBO at our institution. Univariate and multivariate analyses were conducted to identify the prognostic factors for RBO using a competing risk model.

RESULTS: The median overall survival period was 170 days (range 19-775 days). Recurrent biliary obstruction before death was observed in 34 patients (28.6%). The 3-, 6-, and 12-month cumulative incidences of RBO were 14.3%, 21.0%, and 27.7%, respectively. A multivariate analysis indicated that ampullary carcinoma compared with metastatic carcinoma (hazard ratio [HR] = 4.86; 95% confidence interval [CI], 1.74-13.54; P = 0.003) and a stent insertion above the sphincter of Oddi (HR 2.49; 95% CI, 1.11-5.62; P = 0.028) were the independent risk factors for RBO when we considered death to be a competing risk.

CONCLUSION: Ampullary carcinoma and stent insertion above the sphincter of Oddi were risk factors for RBO in these patients who received percutaneous transhepatic stent placement.