Abstract
Background and Study Aims: Clogging of biliary stents continues to be a major clinical problem. Different polymer
materials may have different effects on clogging.In vitrostudies have shown a direct relation between the frictional coefficient of a polymer
and the amount of encrusted material. Teflon 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 favourable patency rates. However, a randomized trial has never
been performed. 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 procedure. Diagnoses included carcinoma of the pancreas
(n = 76), papilla (n = 1), bile duct (n = 5) and metastases (n = 2). The internal
and external diameter (10 Fr), length (9 cm) and stent design (a straight stent with
two side 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 groups (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 both groups. Patient survival did not
differ significantly between the groups (median survival: Teflon 165 days, polyethylene
140 days). The median stent 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.
