Hospital Volume Impacts the Outcomes of Endovascular Repair of Thoracoabdominal Aortic Aneurysms

Abstract

Background: Few centers in the United States have the expertise to manage patients with a thoracoabdominal aortic aneurysm (TAAA). The purpose of this study is to use a nationally representative vascular database to assess the role of hospital volume on outcomes in patients undergoing endovascular repair for TAAA.

Methods: All patients undergoing complex endovascular repair (cEVAR) for TAAA were identified in the Vascular Quality Initiative (VQI) database (2012-2018). The total mean number of cases per year was identified at each center and were used to group into three quantiles containing an equal number of patients (Low [LVH], Medium [MVH], High [HVH]). Standard univariate and multivariable (logistic regression) analyses were performed to evaluate the patient's characteristics and short-term outcomes.

Results: A total of 2,115 patients from 118 centers (Low - 92, Medium - 19, High - 7) were identified in VQI from 2012 to 2018. The annual mean (S.D.) number of cases at HVH, MVH, LVH were 22.7 (4.7), 9.6 (3.0), 3.6 (1.4), respectively. The repair of Type III TAAA was slightly higher in HVH versus MVH versus LVH (22.5% vs. 21.0% vs. 15.1%), while Type I was more common among LVH versus MVH versus HVH (13.7% vs. 11.5% vs. 3.7%) (Both P < 0.001). Custom/modified devices were more likely to be used in HVH versus MVH versus LVH (67.9% vs. 27.6% vs. 27.2%) (P < 0.001). Additionally, HVH and MVH utilized fenestrated/branched or chimney/snorkel options more frequently, whereas surgical bypasses were common in LVH for revascularization of visceral arteries. In univariate analysis, HVH were associated with significantly lower mortality (2.2% vs. 5.1% and 6.5%), failure to rescue [FTR] (3.5% vs. 11.6% and 12.1%) and any complication (24.6% vs. 27.1% and 31.2%) compared to LVH and MVH (All P < 0.001). After adjusting for potential confounders, both LVH and MVH were associated with 2-4 fold increase in the odds of mortality [OR (95% CI): 2.30 (1.20-4.41) and 2.14 (1.16-3.93)] and FTR [OR (95% CI): 4.42 (1.86-10.54) and 4.08 (1.73-9.62)] compared to HVH.

Conclusions: Our study demonstrates significantly lower morbidity and mortality in high volume hospitals performing cEVAR for TAAA, despite operating on older patients with more complex TAAA types. This is likely due to better rescue phenomenon in addition to more experienced operators. Complex endovascular repair of TAAA can be performed safely in high volume aortic centers of excellence.