Metallic vs plastic stents to treat biliary stricture after liver transplantation: a systematic review and meta-analysis based on randomized trials.

 The first-line approach to anastomotic biliary stricture after orthotopic liver transplantation (OLTX) involves endoscopic retrograde cholangiopancreatography (ERCP). The most widely used technique is placement of multiple plastic stents, but discussions are ongoing on the benefits of fully-covered self-expandable metallic stents (FCEMS) in this situation. This study aimed to compare results from use of plastic and metal stents to treat biliary stricture after transplantation.  Searches were performed in the Medline, EMBASE, SciELO/LILACS, and Cochrane databases, and only randomized studies comparing the two techniques were included in the meta-analysis.  Our study included four randomized clinical trials totaling 205 patients. No difference was observed between the stricture resolution rate (RD: 0.01; 95 %CI [-0.08 - 0.10]), stricture recurrence (RD: 0.13; 95 %CI [-0.03 - 0.28]), and adverse events (RD: -0.10; 95 %CI [-0.65 - 0.44]) between the plastic and metallic stent groups. The metallic stent group demonstrated benefits in relation to the number of ERCPs performed (MD: -1.86; 95 %CI [-3.12 to -0.6]), duration of treatment (MD: -105.07; 95 %CI [-202.38 to -7.76 days]), number of stents used (MD: -10.633; 95 %CI [-20.82 to -0.44]), and cost (average $ 8,288.50 versus $ 18,580.00,  < 0.001).  Rates of resolution and recurrence of stricture are similar, whereas the number of ERCPs performed, number of stents used, duration of treatment, and costs were lower in patients treated with FCEMS, which shows that this device is a valid option for initial treatment of post-OLTX biliary stricture.