Active sac management for prevention of type II endoleaks after endovascular aneurysm repair

Background: Type II endoleaks (T2EL) remain the most common complication after endovascular aneurysm repair (EVAR). Aneurysm sac regression is a predictor for better treatment outcomes compared to sac stability and growth. T2EL are associated with aneurysm sac regression and prophylactic embolization of the sac or side branches may result in lower T2EL incidence. This review aims to assess the current evidence on whether prophylactic treatment strategies provide improved clinical outcomes after EVAR. Materials and methods: A systematic search was performed of the Scopus, PubMed and Web of Science databases. Original studies reporting prophylactic embolization to prevent endoleaks were included and a meta-analysis was performed on important clinical outcome parameters; T2EL incidence, sac remodelling and T2EL related reinterventions. Results: A total of 1,870 publications were identified. After screening and quality assessment by two reviewers, data were extracted from 29 studies and analysed. T2EL incidence was significantly lower in the embolization group; odds ratio 0.29 [0.19-0.45, 95% confidence interval] at 6 months, 0.20 [0.13-0.31] at 12 months and 0.28 [0.14-0.55] at 24 months. Sac growth was significantly lower in the embolization group with odds ratios of 0.08 [0.01-0.59], 0.16 [0.05-0.53] and 0.24 [0.11-0.52] at 6, 12 and 24 months, respectively. Sac shrinkage was significantly higher in the embolization group with odds ratios of 0.42 [0.28-0.63], 0.49 [0.32-0.77] and 0.28 [0.16-0.50] at 6, 12 and 24 months, respectively. Reintervention rates were lower in the embolization group, although not statistically significant. Conclusions: The results from this review and meta-analysis show that prophylactic embolization, either through non-selective sac filling or selective side branch embolization, result in better clinical outcomes at 6, 12 and 24 months. Prophylactic embolization seems promising in increasing sac regression rates and reducing T2EL incidence, but more data about other clinical outcome parameters is required.