Association between surgeon case volume and years of practice experience with open abdominal aortic aneurysm repair outcomes.

BACKGROUND

Widespread adoption of endovascular aneurysm repair has led to a consequential decline in the use of open aneurysm repair (OAR). This evolution has had significant ramifications on vascular surgery training paradigms and contemporary practice patterns among established surgeons. Despite being the subject of previous analyses, the surgical volume-outcome relationship has remained a focus of controversy. At present, little is known about the complex interaction of case volume and surgeon experience with patient selection, procedural characteristics, and postoperative complications of OAR. The purpose of the present analysis was to examine the association between surgeon annual case volume and years of practice experience with OAR.

METHODS

All infrarenal OARs (n = 11,900; elective, 70%; nonelective, 30%) included in the Society for Vascular Surgery Vascular Quality Initiative from 2003 to 2019 were examined. Surgeon experience was defined as years in practice after training. The experience level at repair was categorized chronologically (≤5 years, n = 1667; 6-10 years, n = 1887; 11-15 years, n = 1806; ≥16 years, n = 6540). The annual case volume was determined by the number of OARs performed by the surgeon annually (median, five cases). Logistic regression was used to perform risk adjustment of the outcomes across surgeon experience and volume (five or fewer vs more than five cases annually) strata for in-hospital major complications and 30-day and 1-year mortality.

RESULTS

Practice experience had no association with unadjusted mortality (30-day death: elective, P = .2; nonelective, P = .3; 1-year death: elective, P = .2; nonelective, P = .2). However, more experienced surgeons had fewer complications after elective OAR (25% with ≥16 years vs 29% with ≤5 years; P = .004). A significant linear correlation was identified between increasing surgeon experience and performance of a greater proportion of elective OAR (P-trend < .0001). Risk adjustment (area under the curve, 0.776) revealed that low-volume (five or fewer cases annually) surgeons had inferior outcomes compared with high-volume surgeons across the experience strata for all presentations. In addition, high-volume, early career surgeons (≤5 years' experience) had outcomes similar to those of older, low-volume surgeons (P > .1 for all pairwise comparisons). Early career surgeons (≤5 years) had operated on a greater proportion of elective patients with American Society of Anesthesiologists class ≥4 (35% vs 30% [≥16 years' experience]; P = .0003) and larger abdominal aortic aneurysm diameters (mean, 62 vs 59 mm [≥16 years' experience]; P < .0001) compared with all other experience categories. Similarly, the use of a suprarenal cross-clamp occurred more frequently (26% vs 22% [≥16 years' experience]; P = .0009) but the total procedure time, estimated blood loss, and renal and/or visceral ischemia times were all greater for less experienced surgeons (P-trend < .0001).

CONCLUSIONS

Annual case volume appeared to be more significantly associated with OAR outcomes compared with the cumulative years of practice experience. To ensure optimal OAR outcomes, mentorship strategies for "on-boarding" early career, as well as established, low-volume, aortic aneurysm repair surgeons should be considered. These findings have potential implications for widespread initiatives surrounding regulatory oversight and credentialing paradigms.