Endovascular versus open repair of ruptured abdominal aortic aneurysms with hostile neck anatomy

Objective: Aneurysm neck anatomy in ruptured abdominal aortic aneurysms (rAAAs) is often complex, limiting the feasibility of endovascular repair (EVAR). The objective of this study was to compare the outcomes of EVAR and open surgical repair (OSR) for treatment of rAAAs in patients with hostile neck anatomy (HNA). The secondary aim was to review the clinical characteristics and anatomic risk factors predictive of mortality.

Methods: A multi-center retrospective review was performed to identify patients with rAAAs and HNA between 2004 and 2021. HNA was defined as infrarenal aortic neck diameter >28 mm, infrarenal neck length <15 mm or angulation >60 degrees. The primary end point was 30-day all-cause mortality. Secondary end points included 90-day, 1-year and 5-year mortality. Preoperative computed tomography was analyzed using an Aquarius workstation. The Kaplan-Meier method was used to estimate survival, and univariate and multivariate Cox proportional hazard regression analysis was used to assess variables that influenced survival.

Results: 137 patients with rAAAs and HNA underwent infrarenal EVAR or OSR. Overall mean age was 74 ± 10 years and 72% were male. 85 patients (62%) underwent infrarenal EVAR and 52 (38%) underwent OSR. Mean aneurysm size at the time of rupture was 86 ± 22 mm. Patients who underwent OSR were more likely to present with a higher Garland preoperative risk score (P = .05), have a lower pH (P < .001), lower SBP (P < .001) and higher lactate (P = .005). Patients with an infrarenal neck length <15 mm were more likely to undergo OSR (EVAR 64% vs. OSR 87%, P = .004) and patients with an infrarenal neck angle >60 degrees were more likely to undergo EVAR (60% vs. 39%, P = .01). EVAR was associated with lower 30-day (17% vs. 27%; OR 0.6; 95% CI, 0.3-1.2; P = .14) and 90-day (22% vs. 33%; HR 0.6; 95% CI, 0.3-1.2; P = .17) all-cause mortality, however, this was not statistically significant. The overall median follow-up time was 19 (2-66) months. 1-year survival for EVAR and OSR were 75% and 64% (Log-rank P = .14) and 5-year survival for EVAR and OSR were 65% and 55% (Log-rank P = .28). Hemoglobin (P = .009), increasing calcification score (P = .002) and infrarenal neck length <10 mm (P = .01) were associated with all-cause mortality at 30-days for EVAR on multivariate Cox regression analysis. Lactate (P <.001) was the only variable associated with all-cause mortality at 30-days for OSR on multivariate Cox analysis.

Conclusion: Early and long-term survival favored EVAR in comparison to OSR in patients with rAAAs and HNA, however, this was not statistically significant. Calcification of the infrarenal neck and neck length <10 mm were associated with increased 30-day mortality for EVAR while no anatomic variables were specifically associated with 30-day mortality for OSR.