Prospective randomized trial comparing Tannenbaum Teflon and standard polyethylene stents in distal malignant biliary stenosis

Background: Our aim was to compare the clinical efficacy of the Tannenbaum (TB) biliary prostheses, a recently designed Teflon stent without side hole s, with the Cotton-Huibregtse (CH) polyethylene stent. Methods: Fifty-seven patients (26 men, mean age 75.5 years) with unresectab le malignant tumors and distal biliary stenosis were included (38 pancreati c head cancer, 17 cholangiocarcinoma, 2 ampullary cancer). Patients were pr ospectively randomized to have a 10F, 7 cm long TB (29 patients) or CH (28 patients) stent inserted endoscopically. Four patients (2 TB and 2 CH) were excluded: 3 because of the failure of stent insertion and 1 because of a p rotocol violation. The patients were evaluated clinically and, if necessary , with biochemical tests every month until death or until they needed surge ry for symptoms of gastric outlet obstruction. When occlusion or dislocatio n occurred, the stent was replaced with one of the same type. Cumulative st ent patency and patient survival were estimated with the Kaplan-Meier rife- table analysis and compared by log-rank chi-square test. Results: The two groups were comparable in mean age, gender, and diagnosis. The patients were followed for a mean of 145.5 days (range 24 to 613); by the end of the study 47 patients (81%) had died or developed symptoms of ga stric outlet obstruction. Median survival was 88 days (range 24 to 613) in the TB group and 75.6 days (23 to 486) in the CH group. Stent exchange (occ lusion 16, dislocation 3) was necessary for 5 patients in the TB group and 7 in the CH group. No statistical difference was found on comparing the mea n duration of function of the first, second, and third stents (analysis of variance, p = 0.80). The median duration of stent function was 96 days (ran ge 11 to 613) in the TB group and 75.5 days (range 23 to 323) in the CH gro up. No significant difference was found in either survival time (p = 0.48) or stent patency (p = 0.12). Conclusion: This study found no significant advantage of the Tannenbaum pro stheses over the standard polyethylene stent in the palliation for patients with distal malignant biliary stenosis with regard to survival or length o f stent patency.