Fully covered metal biliary stents: A review of the literature

Fully covered self-expandable metal stents(FCSEMS)represent the latest advancement of metal biliary stents used to endoscopically treat a variety of obstructive biliary pathology.A large stent diameter and synthetic covering over the tubular mesh prolong stent patency and reduce risk for tissue hyperplasia and tumor ingrowth.Additionally,FCSEMS can be easily removed.All these features address issues faced by plastic and uncovered metal stents.The purpose of this paper is to comprehensively review the application of FCSEMS in benign and malignant biliary strictures,biliary leak,and post-sphincterotomy bleeding.

Optimization of biliary drainage in inoperable distal malignant strictures

BACKGROUND Given most patients with distal malignant biliary obstruction present in the nonresectable stage,palliative endoscopic biliary drainage with fully covered metal stent(FCMS)or uncovered metal stent(UCMS)is the only available measure to improve patients’quality of life.Half covered metal stent(HCMS)has been recently introduced commercially.The adverse effects and stent function between FCMS and UCMS have been extensively discussed.AIM To study the duration of stent patency of HCMS and compare it with FCMS and UCMS to optimize biliary drainage in inoperable patients with distal malignant obstruction.Secondary aims in our study included evaluation of patients’survival and the rates of adverse events for each type of stent.METHODS We studied 210 patients and randomized them into three equal groups;HCMS,FCMS and UCMS were inserted endoscopically.RESULTS Stent occlusion occurred in(18.6%,17.1%and 15.7%in HCMS,FCMS and UCMS groups,respectively,P=0.9).Stent migration occurred only in patients with FCMS(8.6%of patients).Cholangitis and cholecystitis occurred in 11.4%and 5.7%of patients,respectively,in FCMS.Tumor growth occurred only in 10 cases among patients with UCMS after a median of 140 d,sludge occurred in nine,seven and one patients in HCMS,FCMS and UCMS,respectively(P=0.04).CONCLUSION Given the prolonged stent functioning time,the use of HCMS is preferred over the use of UCMS and FCMS for optimizing biliary drainage in patients with distal malignant biliary obstruction.