Clinical experience with covered wallstents for biliary malignancies: 23-month follow-up

Purpose: To evaluate the effectiveness of partially covered metallic Wallstents to prevent tumoral ingrowth in patients with neoplastic obstruction of the biliary tract. Methods: Twenty-one patients with malignant obstructive jaundice have been treated with Wallstents partially covered with a polyurethane polymer. In total, 36 covered stents (8 and 10 mm in diameter, 70 and 90 mm long) were deployed. All the stents were free from covering at both ends. Results: Jaundice was successfully treated in 100% of cases. There were no problems related to the releasing system during stent positioning, no major complications, and no incompatibility reactions to the materials composing the endoprostheses. At 23-month followup, 6 patients are still alive and 15 are dead; of these 15 patients, 11 died in the first 6 months and the last 4 died between 6 and 23 months. Seven patients had an obstructed stent; in four of these, cholangioscopy showed the presence of tumoral ingrowth and in one it showed necrotic tissue with biliary pigments and inflammatory cells. No biopsy specimen was obtained in the remaining two patients with stent obstruction. The follow-up, ranging from 7 to 23 months, showed a primary patency of 46.8% and 24.6% and an assisted patency of 66.3% and 59% at 6 months and 23 months, respectively. Conclusions: Covered metallic stents are effective and may produce improved survival in patients with malignant biliary obstruction (27.8% at 23 months). Stent patency, however, is similar to that of uncovered stents. Modifications in the design of the covering membrane may reduce stent obstruction resulting from disruption of the plastic covering.