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

Abstract

Observational data from national and international registries have shown that endovascular repair carries a lower peri-operative mortality risk than open repair for ruptured abdominal aortic aneurysm (AAA). Patient selection may explain the superiority of endovascular aneurysm repair (EVAR), with hostile aortic anatomy being a confounding factor. This study is a meta-analysis of outcomes in patients with hostile vs. friendly aortic anatomy treated for ruptured AAA. It was found that patients with hostile aortic anatomy undergoing EVAR have higher peri-operative mortality and lower overall survival. No significant differences in mortality were found for patients treated by open repair.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 metaanalysis 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 1.13e2.66; p ¼ .01). Subgroup analysis showed a significant difference in perioperative mortality in favour of friendly anatomy in patients treated by EVAR (OR 1.76, 95% CI 1.01e3.08; p ¼ .05), but not in those treated by open repair (OR 1.37, 95% CI 0.83e2.27; p ¼ .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 1.18e3.44, p ¼ .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 0.61e1.32, p ¼ .58). Conclusion: Hostile aortic anatomy is associated with increased mortality in patients with ruptured AAA treated by EVAR.

AAA Revisited: A Comprehensive Review of Risk Factors, Management, and Hallmarks of Pathogenesis

“…Analyses of earlier versus later cohorts show that outcomes have improved in recent years for both EVAR and OSR [ 310 , 311 ]. High mortality rates of unsuccessful EVAR for rAAA suggest that anatomical suitability and not hemodynamic condition should be the pivotal factor in choosing the surgical method for rAAA repair [ 251 , 312 , 313 ].…”

Preoperative risk score accuracy confirmed in a modern ruptured abdominal aortic aneurysm experience

“…Although previous studies have confirmed that hostile aneurysm anatomy is associated with worse outcomes after EVAR, the relative importance of these "hostile factors" and any changes in their prevalence over time has remained undefined. 27,28 Finally, we found that an elevated INR and heart rate (>110 bpm) were significantly associated with greater 30-day mortality after repair, even after adjustment for the HRS and surgical repair type. Potential modification of the HRS remains a topic of ongoing research.…”

A comparison of endovascular versus open repair for ruptured abdominal aortic aneurysm – Meta-analysis of propensity score-matched data

“…Perioperative mortality can be affected by a plethora of variables such as pre- and post-operative factors, anatomical factors and operative factors. 24 Propensity-matching patients on a 1:1 basis can significantly reduce the effect of these variables, which most included studies did in this meta-analysis. The study by Saqib et al 19 propensity-matched on a 1:3 basis due to a small sample size.…”

“…Aortic morphology has been suggested as an important factor in determining perioperative outcomes. 24 Aneurysmal neck length has been found to be a key predictor of mortality. 3,30 This study was unfortunately unable to explore this further due to the limitations in the databases.…”