Covered Metal Stents vs. Multiple Plastic Stents for Management of Benign Biliary Strictures: A Systematic Review and Meta-analysis 2016 ACG Presidential Poster Award

Abstract

Introduction: Endoscopic treatment of benign biliary strictures (BBS) can be achieved by placement of multiple plastic stents (MPS) or covered self-expandable metal stents (cSEMS). We conducted a systematic review and meta-analysis to evaluate the cumulative efficacy (stricture resolution & recurrence) and safety (adverse events) of cSEMS for treatment of BBS. We also compared the efficacy and safety of MPS that of cSEMS in the management of BBS.Figure 1Methods: We searched Medline and Embase from inception to 05/28/16 to identify both observational studies evaluating the stricture resolution rate and safety of cSEMS in BBS and randomized controlled trials (RCTs) comparing cSEMS with plastic stents for management of BBS. Weighted pooled rates (WPR) were calculated for stricture resolution/recurrence with the use of cSEMS. Risk ratios (RR) were calculated for stricture resolution, recurrence and adverse events (AEs) while comparing cSEMS with plastic stents. Difference in means was calculated for number of ERCPs required in each group. These were analyzed using random effects model. Meta-regression was done to explore heterogeneity. Quality assessment was done with Cochrane tool and Newcastle Ottawa Scale (NOS) for RCTs and observational studies, respectively. Results: Twenty three studies with 1175 patients were included in the meta-analysis to evaluate the cumulative efficacy and safety of cSEMS & 4 RCTs with 213 patients were included in the comparative analysis of cSEMS and plastic stents. All RCTs had high risk of performance bias. On NOS evaluation, 4, 12 and 3 studies were of high, moderate and low quality. WPR for cumulative stricture resolution with cSEMS was 84% (79%, 88%), with considerable heterogeneity (I2=73%). WPR for stricture recurrence was 14% (9%,19%), with moderate heterogeneity (I2=58%). Rates of AEs requiring intervention were: stent migration with cholangitis (1%), stent occlusion with cholangitis (4%), cholangitis after stent removal (1%), cholecystitis (1%) and pancreatitis (4.5%). Rate of asymptomatic stent migration before scheduled removal was 8.7%. The pooled RR comparing cSEMS with MPS for stricture resolution was 1.07 (0.97, 1.18) with no heterogeneity (I2=0%). RR for stricture recurrence was 0.88 (0.48,1.63) with no heterogeneity (I2=0%) and for AEs was 1.11 (0.49,2.51) with low heterogeneity (I2=30%). Difference in means for number of ERCPs required was -1.66 (-2.38,-0.91) with low heterogeneity (I2=52%) in favor of cSEMS.Figure 2Figure 3Conclusion: cSEMS have a cumulative stricture resolution and recurrence rates of 84% and 14%, respectively. No difference was found in stricture resolution, stricture recurrence and AEs between cSEMS and plastic stents. However, cSEMS treatment was associated with significantly fewer ERCP sessions.