Management of anastomotic biliary stricture after liver transplantation: metal versus plastic stent

Background Post-transplant anastomotic biliary strictures remain refractory to endoscopic therapy in a considerable number of cases. The aim of this meta-analysis was to compare fully-covered self-expandable metal and plastic stents in the management of post-transplant biliary strictures. Methods A meta-analysis was performed using a random effects model; results were expressed as odds ratio (OR) and mean standardized difference. The primary outcome was stricture resolution, while recurrence rate after stent placement, treatment time, and safety of the procedure were the secondary outcomes. Results Through a systematic literature review until October 2017, we identified 7 studies, of which 4 were randomized controlled trials. Stricture resolution was slightly higher with metal stents, with no statistical difference between the two procedures (OR 1.38, 95% confidence interval [CI] 0.60-3.15; P=0.45) and low heterogeneity (I-2=6%). Stricture recurrence showed a non-significant trend in favor of plastic stents (OR 1.82, 95% CI 0.52-6.31, P=0.35). Endoscopic retrograde cholangiopancreatography with placement of metal stents offered a significant improvement in terms of reduced treatment time (mean standardized difference: -3.58 months, 95% CI -6.23 to -0.93; P=0.008), but with more frequent complications, although not significantly so (OR 2.34, 95% CI 0.75-7.25; P=0.14). Sensitivity analysis confirmed all the findings. Conclusion Metal stents appear to be a promising tool that can decrease treatment time, although there is still no clear evidence of their superiority over plastic stents in terms of efficacy.