Introduction
Anastomotic biliary strictures represent a significant burden after orthotopic liver transplantation, with challenging endoscopic treatment. The selection of the optimal approach regarding type of stents remains controversial due to the absence of strong evidence. The European Society of Gastrointestinal Endoscopy recommends stricture remodeling using multiple plastic stents (MPS),1 whereas the American College of Gastroenterology supports the use of fully covered self-expandable metal stents (FC-SEMS),2 as for every benign biliary stricture. In the absence of cumulative comparisons and considering the development of intraductal SEMS (ID-SEMS), which are promising for this type of strictures, this systematic review with meta-analysis aimed to evaluate the potential differences in the performance of the available stents in post-transplant anastomotic biliary strictures management.
Aims & Methods
The systematic research was performed in MEDLINE, Cochrane, and Scopus databases until April 2023 for comparative studies evaluating the successful stricture management using MPS and SEMS, including FC-SEMS and ID-SEMS. The primary outcome was stricture resolution after completion of therapy, documented by cholangiogram or cross-sectional imaging. Secondary outcomes included stricture recurrence (clinical and biochemical relapse with imaging confirmation) during the follow-up period, stent migration and adverse events. Quality assessment was based on the Newcastle-Ottawa scale. Meta-analyses were based on random effects model and the results were reported as odds ratios (OR), with 95% Confidence Intervals (95%CI). Subgroup analyses by type of metal stent were performed to explore the diversity among the results of different studies.
Results
Nine studies with an overall number of 687 patients were included in our analysis, with three of them being randomized controlled trials. Metal stents were placed in 251 cases (82 ID-SEMS and 169 FC-SEMS) and MPS in 436. Considering the primary outcome, metal and plastic stents did not differ significantly in stricture resolution with OR: 0.99 (95%CI: 0.48-2.01; I2=35%). Stricture recurrence and migration rates were also comparable between the two arms [OR: 1.71 (95%CI: 0.87-3.38; I2=55%) and OR: 0.73 (95%CI: 0.32-1.68; I2=56%) respectively]. All of these outcomes presented with moderate heterogeneity. Finally, the difference between adverse events rates was non-significant [OR: 1.47 (95%CI: 0.89-2.43; I2=24%)]. Interestingly, in the subgroup analysis ID-SEMS provided significantly higher complete resolution rates with low heterogeneity compared to the MPS [OR: 3.48 (95%CI: 0.89-13.62; I2=5%)], whereas the comparison between FC-SEMS and MPS did not reach significance [OR: 0.76 (95%CI: 0.42-1.39; I2=11%)]. Relative recurrence rates did not differ between subgroups [for ID-SEMS vs MPS, OR: 1.01 (95%CI: 0.51-2.03; I2=0%; for FC-SEMS vs MPS, OR:2.39 (95%CI: 0.87-6.56; I2=66%)]. On the other hand, migration rates were significantly lower for ID-SEMS compared to MPS, with OR: 0.28 (95%CI: 0.11-0.70; I2=0%), and equivalent for FC-SEMS and MPS [OR: 1.25 (95%CI: 0.54-2.88; I2=40%)]. Complication rates were similar for ID-SEMS and MPS [OR: 0.90 (90%CI: 0.28-2.84; I2=47%)], but their prevalence after FC-SEMS were significantly higher compared to MPS [OR: 1.76 (95%CI: 1.06-2.93; I2=0%)].
Conclusion
The comparison between metal stents and MPS did not result to significant differences in any outcome. However, ID-SEMS appeared superior to MPS in stricture resolution and migration rates, whereas FC-SEMS provided comparable outcomes to MPS.
References
1. Dumonceau JM, Tringali A, Papanikolaou I, Blero D, Mangiavillano B, Schmidt A, et al. Endoscopic biliary stenting: indications, choice of stents, and results: European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline – Updated October 2017. Endoscopy. 2018 Sep 7;50(09):910–30.
2. Elmunzer BJ, Maranki JL, Gómez V, Tavakkoli A, Sauer BG, Limketkai BN, et al. ACG Clinical Guideline: Diagnosis and Management of Biliary Strictures. American Journal of Gastroenterology. 2023 Mar;118(3):405–26.
