Safety and Efficacy of Thrombin for Bleeding Gastric Varices: A Systematic Review and Meta-Analysis

Introduction: The optimal therapy for bleeding-related gastric varices is still a controversial topic. There is a paucity of literature that comprehensively summarizes the available literature regarding safety and efficacy of thrombin in bleeding gastric varices. Methods: Four independent reviewers performed a comprehensive review of all original articles published from inception to October 2020, describing the use of thrombin for management of bleeding gastric varices. Primary outcomes were (1) pooled early and late rebleeding rate, (2) pooled gastric variceal related mortality rate, (3) pooled rescue therapy rate, and (4) pooled adverse event rate with the use of thrombin in bleeding gastric varices. The meta-analysis was performed and the statistics were two-tailed. Finally, probability of publication bias was assessed using funnel plots and with Egger’s test. Results: Eleven studies were included in the analysis after comprehensive search. This yielded a pooled early rebleeding rate of 9.3% (95% CI 4.9–17) and late rebleeding rate 13.8% (95% CI 9–20.4). Pooled rescue therapy rate after injecting thrombin in bleeding gastric varices was 10.1% (95% CI 6.1–16.3). The pooled 6-week gastric variceal-related mortality rate after injecting thrombin in bleeding gastric varices was 7.6% (95% CI 4.5–12.5). There were a total of four adverse events out of a total of 222 patients with pooled adverse event rate after injecting thrombin in bleeding gastric varices was 5.6% (95% CI 2.9–10.6). Conclusion: In summary, the systematic review and meta-analysis on the use of thrombin for bleeding gastric varices suggest low rates of rebleeding and minimal rates of adverse events. While, early and late rebleeding rate and rescue therapy rate are similar to cyanoacrylate-based therapy, the minimal rates of adverse events are perhaps the most important benefit of thrombin. Thus, the current data suggest that thrombin is a very promising therapeutic alternative with low risk of adverse events for bleeding gastric varices.