A prospective randomized trial of Teflon versus polyethylene stents for distal malignant biliary obstruction

Background and study Aims: Clogging of biliary stents continues to be a maj or clinical problem. Different polymer materials may have different effects on clogging. In vitro studies have shown a direct relation between the fri ctional coefficient of a polymer and the amount of encrusted material. Tefl on appeared to be the best polymer for biliary stents. Two different types of stents made of Teflon have been tested in clinical practice and showed f avourable patency rates. However, a randomized trial has never been perform ed. We compared the patency of an Amsterdam-type polyethylene stent with a Teflon stent in a prospective randomized trial, Patients and Methods: Between September 1995 and November 1996, 42 patients received a Teflon stent and 42 patients a polyethylene stent, All patients had a distal malignant biliary stricture without a previous drainage proce dure. Diagnoses included carcinoma of the pancreas (n = 76), papilla (n = 1 ), bile duct (n = 5) and metas tases (n = 2). The internal and external dia meter (10 Fr), length (9 cm) and stent design (a straight stent with two si de flaps and one side hole at each end) were similar for both stents, Results: A reduction in bilirubin of more than 20% within one week was seen in 91% of the patients. Early complication rates were similar in both grou ps (10%), The median follow-up was 142 days. Stent dysfunction occurred in 28 Teflon and 29 polyethylene stents, The thirty-day mortality was 14% in b oth groups, Patient survival did not differ significantly between the group s (median survival: Teflon 165 days, polyethylene 140 days). The median ste nt patency was 83 days for Teflon and 80 days for polyethylene stents, and was not significantly different either. Conclusion: Teflon material did not improve patency in biliary stents with an Amsterdam-type design.