BACKGROUND

We evaluate the relationship between the hospital case volume (HCV) and mortality outcomes after open aortic repair (OAR) and endovascular aortic repair (EVAR) of intact (iEVAR) and ruptured (rEVAR) abdominal aortic aneurysm (AAA) using a contemporary administrative database.

METHODS

The Healthcare Cost and Utilization Project Database for New York (2016) and New Jersey/Maryland/Florida (2016-2017) were queried using International Classification of Disease-10th edition to identify patients who had undergone OAR and EVAR. The hospitals were categorized into quartiles (Q) per overall (EVAR + OAR) volume, OAR-alone volume and EVAR-alone volume. Cox regression adjusted for confounding factors was used to estimate hazard ratios (HRs) for mortality.

RESULTS

A total of 8,825 patients (mean age, 73.5 ± 9.5 years; 6,861 male [77.7%]) had undergone 1,355 OARs and 7,470 EVARs. Overall HCV had no impact on in-hospital mortality across quartiles after (iEVAR) (range, 0.7%-1.4%, P = 0.15), (rEVAR) (range, 20.5%-29.6%, P = 0.63) and open repair of intact AAA (iOAR) (range, 4.9%-8.8%, P = 0.63). However, the mortality rates after open repair of ruptured AAA (rOAR) in highest-volume (Q4) hospitals were significantly lower than those in the 3 lower quartile hospitals (23.1% vs. 44.7%, P < 0.001). When analyzed per OAR-alone volume, the same findings were observed (22.0% for Q4 vs. 41.6% for Q1-3, P < 0.001). Furthermore, in Q4 hospitals per the OAR-alone volume analysis, the mortality hazard was greater for rEVAR (39.0%) than for rOAR (22.0%) (HR = 2.3, 95% confidence interval, 1.02-5.34, P < 0.05).

CONCLUSIONS

The mortality rates for iEVAR, rEVAR and iOAR were independent of HCV. However, after rOAR, mortality rates in high OAR volume hospitals were lower than those in the lower quartile hospitals, and, at least comparable to those of rEVAR. EVAR-first strategy for ruptured AAA might not be applicable to all cases. Patent-specific, individualized treatment should be the gold standard. For patients requiring rOAR, transfer to a regional center of excellence, when clinical safe, should be encouraged.