Sealing Devices in Chimney Aortic Repair (CH EVAS) Versus Chimney Aortic Repair with Conventional Devices (CH EVAR): A Systematic Review.

Aim: The aim of this study was to review the literature about the occurrence of postoperative type I endoleak (EL) and chimney graft thrombosis (CGT) after the use of sealing devices in chimney endovascular aortic repair (Ch EVAS), compared to chimney EVAR using conventional devices (Ch EVAR).
Methods: A systematic review of the literature on PubMed and MEDLINE with the terms "Chimney" and "Parallel grafts" was performed. The review was set up following the PRISMA guidelines. Case series about the use of the chimney/snorkel technique during endovascular repair of juxtarenal/pararenal aneurysms (AAA) were considered. Only papers with full text available in English and reporting complete data with at least 1 month of follow-up about at least 5 cases were included in the analysis.
Results: In total, 90 papers were assessed for eligibility. According to the inclusion criteria, only 25 papers could be analyzed (20 in the Ch EVAR group and 5 in the Ch EVAS group). A type I EL occurred in 9.3% after Ch EVAR (95% CI 7.1-12.2%) and in 8.3% after Ch EVAS (95% CI 3.5-18.5%), being not significantly different. CGT occurred in 10.7% of cases after Ch EVAR (95% CI 8.8-13%) and in 8.8% of cases after Ch EVAS (95% CI 3.3-21.3%), being also not significantly different.
Conclusions: The reported rate of type I EL and CGT occurring after Ch EVAR tended to be slightly higher than those reported after Ch EVAS, even if the difference was not statistically significant.