Trends in annual open abdominal aortic surgical volumes for vascular trainees compared to annual national volumes in the endovascular era

OBJECTIVE

Prior analysis predicted a shortfall in open abdominal aortic repair (OAR) experience for vascular trainees resulting from the rapid adoption of and increased anatomic suitability of endovascular aortic repair (EVAR) technology. We explored how EVAR has transformed contemporary open aortic surgical education for vascular trainees.

METHODS

We examined ACGME case volumes of open abdominal aortic aneurysm (AAA) repair and reconstruction for aorto-iliac occlusive disease (AIOD) via aorto-iliac/femoral bypass (AFB) from integrated vascular surgery residents (VSR) and fellows (VSF) graduating 2006-2017 and compared them to national estimates of total OAR (open AAA repair + AFB) in the Agency for Healthcare Research and Quality National Inpatient Sample based on ICD-9 and ICD-10 procedural codes. Changes over time were assessed using Chi-square test, Student's t-test, and linear regression.

RESULTS

During the twelve-year study period, the national annual total OAR and open AAA repair estimates decreased: total OAR by 72.5% (2006: estimate (standard error) 24,255 (1185) vs. 2017: 6,690 (274); p<0.001) and open AAA repair by 84.7% (2006: 18,619 (924) vs. 2017: 2,850 (168); p<0.001); AFB estimates decreased by 33.0% (p<0.001). The percentage of total OAR, open AAA repair, and AFB performed at teaching hospitals significantly increased from ∼55 to 80% (all p<0.001). There was a 40.9% decrease in open AAA repairs logged by graduating VSF (mean 18.6 vs. 11) but only a 6.9% decrease in total OAR cases (mean 27.6 vs. 25.7) due to increasing AFB volumes (mean 9.0 vs. 14.7). VSR graduates consistently logged an average of ∼10 open AAA repairs and there was a 31.0% increase in total OAR (mean 23.2 vs. 30.4), again secondary to rising AFB volumes (mean 11.4 vs 17.5). Although there was an absolute decrease in open aortic experience for VSF, the rate of decline for total OAR case volumes was not significantly different after VSR programs were established (p=0.40).

CONCLUSIONS

As incidence decreases nationally, OAR is shifting towards teaching hospitals. While open AAA procedures for trainees are declining due to EVAR, open aortic reconstruction for AIOD is rising and plays an important role in ensuring that vascular trainees continue to have satisfactory OAR experience sufficient for meeting minimum graduation requirements. Strategies to maintain and maximize the education and experience from these cases should be top priority for vascular surgery program directors.