Prognosis Systematic Review and Meta-Analysis of Outcomes of Open and Endovascular Repair of Ruptured Abdominal Aortic Aneurysm in Patients with Hostile vs. Friendly Aortic Anatomy

Objective To investigate the effect of hostile aortic anatomy on the outcomes of endovascular and open repair for ruptured abdominal aortic aneurysm (AAA). Methods Electronic bibliographic sources (MEDLINE, EMBASE, CENTRAL) were searched using a combination of thesaurus and free text terms to identify studies comparing treatment outcomes of ruptured AAA in patients with hostile vs. friendly aortic anatomy. A systematic review was conducted that conformed to the PRISMA guidelines using a registered protocol (CRD42019127307). The primary outcomes were peri-operative mortality, freedom from aneurysm related mortality, and overall survival. Pooled estimates of dichotomous outcomes were calculated using odds ratio (OR) and 95% confidence interval (CI). A time to event data meta-analysis was conducted using the inverse variance method and the results were reported as summary hazard ratio (HR) and associated 95% CI. Subgroup analysis for type of treatment (endovascular aneurysm repair [EVAR] or open repair) was undertaken. Random effects models of meta-analysis were developed. Results Ten observational studies were included reporting a total of 1284 patients (748 with hostile anatomy and 536 with friendly anatomy). Patients with hostile anatomy had a higher peri-operative mortality than patients with friendly anatomy (OR 1.73, 95% CI 1.13–2.66; p = .01). Subgroup analysis showed a significant difference in peri-operative mortality in favour of friendly anatomy in patients treated by EVAR (OR 1.76, 95% CI 1.01–3.08; p = .05), but not in those treated by open repair (OR 1.37, 95% CI 0.83–2.27; p = .22). Patients with hostile anatomy treated by EVAR had a significantly higher hazard of death in follow up than patients with friendly aortic anatomy (HR 2.01, 95% CI 1.18–3.44, p = .01), whereas for open surgical repair, the survival was similar in patients with hostile and those with friendly aortic anatomy (HR 0.90, 95% CI 0.61–1.32, p = .58). Conclusion Hostile aortic anatomy is associated with increased mortality in patients with ruptured AAA treated by EVAR.