Systematic review and meta-analysis on prophylactic aortic side branch embolization to prevent type II endoleaks.

Abstract Objective Type II endoleaks are the most common type of endoleaks after EVAR and may cause late sac expansion and rupture. To prevent this, prophylactic embolization of aortic side branches has been suggested. The aim of this review was to assess the current evidence for this prophylactic treatment and its association with sac size enlargement, as well as rate of and re-intervention for type II endoleaks. Methods This was a systematic review and meta-analysis following the PRISMA guidelines. The MEDLINE and Scopus databases were used to search for related articles until March 2019. After screening, original studies reporting outcome comparing prophylactic embolization to those undergoing EVAR without prophylactic embolization were included. An assessment of the quality of the included studies, as well as data extraction, was performed by two independent observers. Statistical analysis was performed using ReviewManager 5.3. Results 3,777 publications were identified. After eliminating duplicated entries, review of titles and abstracts, 13 retrospective cohort studies, including 1,427 patients, comparing prophylactic embolization to standard EVAR therapy were identified. No randomized trials were available. Five of these 13 studies reported sac growth, with the frequency 7.4% (14/90) in the embolization group vs. 13.4% in controls, odds ratio 0.54 (95% CI 0.29 - 1). The rate of type II endoleaks was 18.5% (100/540) in the embolization group vs. 38.6% in the control group (342/887), odds ratio 0.34 (95% CI 0.26 - 0.44). Based on ten studies, the rate of re-intervention was 1.5% (7/468) in the embolization group vs. 12.4% (80/646) in the control group, odds ratio 0.12 (95% CI 0.06 - 0.24). Nine of these 13 studies showed that technical success of IMA and LA embolization were 82.3% and 69.1% respectively. Regarding complications, ten of 108 patients (9.3%) in one study reported non-specific abdominal pain after embolization, and all resolved with overnight rehydration. Only 1/1427 patient, who had prior right hemicolectomy, died after IMA embolization due to ischemic colitis. Conclusions This systematic review and meta-analysis suggest that prophylactic aortic side branch embolization may be associated with lower rate of sac enlargement, incidence of type II endoleaks and re-interventions. However, high-quality unbiased studies are lacking in this field, and this review and meta-analysis may be affected by selection bias and residual confounders remaining in the retrospective studies. To conclude whether prophylactic embolization should be routinely performed, a prospective, randomized trial would be required.