Percutaneous management of hilar biliary malignancies with metallic endoprostheses: results, technical problems, and causes of failure.

Malignant obstruction at the biliary hilum is a challenging problem for percutaneous management because of the anatomy of the biliary hilum, which facilitates spread of tumor into multiple biliary radicles. Metallic self-expanding stents were used in 22 patients with hilar malignancies. Sixteen patients had focal common hepatic duct strictures, and six had multisegmental disease. Stents were placed in the biliary system with a single transhepatic approach in 16 patients with common hepatic duct strictures; stent placement in the right and left biliary ducts was performed with a bilateral transhepatic approach in five patients and with a single transhepatic approach in one patient. Metal stent occlusion occurred in six patients (27%) at a mean of 2.5 months after initial insertion. Stent occlusion was due to inspissated debris in two of these patients and to tumor overgrowth in four. The key to successful long-term treatment is to "overstent" to ensure adequate purchase above hilar tumors and insertion in a balanced position. Thus, the prevalence of tumor overgrowth is decreased.