Sac Embolization and Side Branch Embolization for Preventing Type II Endoleaks After Endovascular Aneurysm Repair: A Meta-analysis

Purpose:To investigate the efficacy and safety of preoperative side branch embolization or intraoperative sac embolization for preventing type II endoleaks after endovascular aneurysm repair (EVAR). Materials and Methods: A systematic literature search of MEDLINE and EMBASE was performed to identify studies that evaluated the outcomes of sac embolization vs no embolization or side branch embolization vs no embolization in patients who received EVAR. Among the 904 studies screened, 17 studies with 2084 participants were included in this review. Outcome measures included the type II endoleak rate, the reintervention rate for type II endoleaks, the incidence of types I/III endoleaks, and the rate of complications. Fixed (no heterogeneity) or random effects models were constructed for each outcome; the results are presented as the odds ratio (OR) with 95% confidence interval (CI). Results: The sac embolization group had significantly lower type II endoleak (OR 0.21, 95% CI 0.13 to 0.34, p<0.001) and reintervention (OR 0.15, 95% CI 0.07 to 0.33, p<0.001) rates than the no embolization group. No significant differences between the 2 groups were found for the type I/III endoleak rate (OR 0.57, 95% CI 0.23 to 1.37, p=0.21) or complication rate (OR 1.22, 95% CI 0.32 to 4.70, p=0.77). Compared with no embolization, side branch embolization was also associated with a decrease in type II endoleak (OR 0.35, 95% CI 0.21 to 0.60, p<0.001) and reinterventions (OR 0.10, 95% CI 0.04 to 0.27, p<0.001). One severe procedure-related complication (fatal colon ischemia) was reported in the side branch embolization group. Conclusion: Sac embolization and side branch embolization are safe and effective in preventing type II endoleaks. Further randomized trials are needed to directly compare the clinical outcomes of these procedures.