MALIGNANT BILIARY OBSTRUCTION - CLINICAL AND HISTOPATHOLOGIC CORRELATION AFTER TREATMENT WITH SELF-EXPANDING METAL PROSTHESES

PURPOSE: To analyze clinical and autopsy findings in patients with malignant biliary obstruction treated with biliary endoprostheses. MATERIALS AND METHODS: Stents were inserted endoscopically in nine patients and transhepatically in 50. In 24 patients, autopsy was performed; in 22 cases, histologic analysis of the area in which the stent was placed was available. RESULTS: The technical success rate was 100%, and the clinical success rate was 92%. Complications occurred in 16 patients, with one procedure-related death. The rate of severe complications was 19%, primarily due to acute cholangitis (n = 9). Mean survival time was 175 days. Stent obstruction was found in 12 patients and occurred on average 196 days after stent placement. Secondary treatment was successful in all 12 patients. Only one of 24 autopsy specimens demonstrated macroscopic nonobstructive tumor ingrowth. Histologic analysis showed that the main reaction to the stent was connective tissue formation, which never occurred before 3 months. Invasion by tumor cells was noted in only five eases. CONCLUSION: Tumor ingrowth is not a major cause of stent obstruction.