van Berkel A M, Boland C, Redekop W K, Bergman J J, Groen A K, Tytgat G N, Huibregtse K
Dept. of Gastroenterology, Academic Medical Center, University of Amsterdam, The Netherlands.
Endoscopy. 1998 Oct;30(8):681-6. doi: 10.1055/s-2007-1001388.
Clogging of biliary stents continues to be a major clinical problem. Different polymer materials may have different effects on clogging. In vitro studies 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.
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.
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.
Teflon material did not improve patency in biliary stents with an Amsterdam-type design.
胆管支架堵塞仍是一个主要的临床问题。不同的聚合物材料对堵塞可能有不同的影响。体外研究表明，聚合物的摩擦系数与结痂物质的量之间存在直接关系。聚四氟乙烯似乎是胆管支架的最佳聚合物。两种不同类型的聚四氟乙烯支架已在临床实践中进行了测试，并显示出良好的通畅率。然而，从未进行过随机试验。我们在一项前瞻性随机试验中比较了阿姆斯特丹型聚乙烯支架与聚四氟乙烯支架的通畅情况。
1995年9月至1996年11月期间，42例患者接受了聚四氟乙烯支架，42例患者接受了聚乙烯支架。所有患者均有远端恶性胆管狭窄，且此前未进行过引流手术。诊断包括胰腺癌（n = 76）、乳头癌（n = 1）、胆管癌（n = 5）和转移癌（n = 2）。两种支架的内径和外径（10 Fr）、长度（9 cm）以及支架设计（一种带有两个侧翼和两端各一个侧孔的直支架）均相似。
91%的患者在一周内胆红素降低超过20%。两组的早期并发症发生率相似（10%）。中位随访时间为142天。28个聚四氟乙烯支架和29个聚乙烯支架出现支架功能障碍。两组的30天死亡率均为14%。两组患者的生存情况无显著差异（中位生存期：聚四氟乙烯组165天，聚乙烯组140天）。聚四氟乙烯支架的中位通畅时间为83天，聚乙烯支架为80天，两者也无显著差异。
聚四氟乙烯材料并未改善阿姆斯特丹型设计的胆管支架的通畅情况。
