Low-volume surgeons can have better outcomes at certain hospital settings for open abdominal aortic repairs

The volume-outcomes relationship is cross-cutting among open abdominal aortic operations, where higher-volume surgeons have better perioperative outcomes. However, there has been minimal focus on low-volume surgeons and how to improve their outcomes. This study sought to identify if there are any differences in outcomes among low-volume surgeons for open abdominal aortic surgeries by different hospital settings.

We used the 2012-2019 Vascular Quality Initiative registry to identify all patients who underwent open abdominal aortic surgery for aneurysmal or aorto-iliac occlusive disease by a low-volume surgeon (<7 operations annually). We categorized high-volume hospitals using three distinct definitions: those that performed ≥10 operations annually, those with at least one high-volume surgeon, and by the number of surgeons (1-2 surgeons, 3-4 surgeons, 5-7 surgeons, and 8+ surgeons). Outcomes included 30-day perioperative mortality, overall complications, and failure-to-rescue. We compared outcomes among low-volume surgeons using univariable and multivariable logistic regressions across each of these three hospital categorizations.

Among 14,110 patients who underwent open abdominal aortic surgery, 10,252 (7 3%) were performed by 1155 low-volume surgeons. Two-thirds of these patients (66%) underwent their surgery at a high-volume hospital, fewer than one-third (30%) at a hospital that had at least one high-volume surgeon, and one-half (49%) at hospitals with at least five surgeons. Among all patients operated on by low-volume surgeons, rates of 30-day mortality were 3.8%, perioperative complications were 35.3%, and failure-to-rescue were 9.9%. Low-volume surgeons operating at high-volume hospitals for aneurysmal disease had lower rates of perioperative death (adjusted odds ratio [aOR], 0.66; 95% confidence interval [CI], 0.48-0.90) and failure-to-rescue (aOR, 0.70; 95% CI, 0.50-0.98), but similar rates of complications (aOR, 1.06; 95% CI, 0.89-1.27). Similarly, patients undergoing their operation at hospitals that had at least one high-volume surgeon had lower rates of death (aOR, 0.71; 95% CI, 0.50-0.99) for aneurysmal disease. Patient outcomes among low-volume surgeons for aorto-iliac occlusive disease did not vary by hospital setting.

The majority of patients undergoing open abdominal aortic surgery have a low-volume surgeon, where outcomes are slightly better for those taking place at a high-volume hospital. Focused and incentivized interventions may be needed to improve outcomes among low-volume surgeons across all practice settings.