Multicentre Trial of A New Endobiliary Stent (diamond (Tm)).

Self-expanding metallic stents (SEMS) are mainly used in the palliative treatment of malignant stenoses of the common bile duct (CBD).Their use in benign disease is more controversial because of the long-term risk of granulomatous obstruction and they are usually reserved for patients at high operative risk after plastic prostheses have proved ineffective.The Diamond TM prosthesis is a new type of "memory" SEMS constructed of nitinolwire strands laser welded in a configuration conferring high radial force and kink-resistant properties.The sheath is compressed onto a flexible delivery catheter by a transparent oversheath with a 3 mm outer diameter.The post deployment diameter is 10 mm and stent lengths of 4, 6, and 8 cm are available.In this multicentre study, we evaluated preliminary experience with this novel prosthesis in human subjects.Methods.Between Oct. '96 and Oct. '97, insertion of a Diamond TM endobiliary stent, under endoscopic and radiographic control, was attempted in 38 patients with malignant biliary strictures (n=31) and in selected patients with benign biliary strictures (n=7).Outcome measures were satisfactory placement, immediate (<48 hr) and short term (day 30) complications, and stent patency (early, at day 30, and longterm, as assessed by the need for further intervention).Results.The mean age was 79.9 years (range 62-98) and 4 cm (n=ll), 6 cm (n=16), and 8 cm (n=l 1) stents were used.The stenosis was situated in the lower portion of the CBD in 28 cases.Deployment was successful in 37/38 (97.4%).The one failure was due to breakage of the deployment cord during insertion.Prior balloon dilatation of the stenosis was performed in 14/38 (36.8%).No immediate or short-term complications related to prosthesis insertion occurred.Immediate post-insertion drainage of the biliary system (clinically and radiographically) was adequate in all 37 subjects.By day 30, the mortality rate was 2/37 (5.4%) (congestive cardiac failure at day 4 and portal vein thrombosis at day 15).In the remaining 35 subjects, relief of biliary obstruction was satisfactory in all at day 30 and no further interventions were necessary.Long-term follow-up data (mean 86 days, range 44 -210 days) regarding stent patency were available in 18 cases.No further intervention was necessary in 16/18 cases (88.9%).In one case insertion of a plastic prosthesis was necessary due to acute cholangitis at day 73, and in another case invasion of the stent from adjacent malignant duodenal infiltration occurred at day 42.~0ndusi0n, The "'memory" Diamond TM prosthesis appears to be useful for endoscopic treatment of biliary stenoses.Its deployment is relatively facile and reliable.Large prospective, randomised studies are justified to clarify its role in the treatment of biliary disease.