Implementation of a Vascular Acute Care Surgery Model is Associated with Improved Surgeon Efficiency and Two-Year Mortality After Lower Extremity Intervention.

ABSTRACT

OBJECTIVE: Vascular surgeons work long, unpredictable hours with repeated exposure to high-stress situations. Inspired by general surgery acute care surgery models, we sought to organize the care of vascular emergencies with the implementation of a vascular acute care surgery (VACS) model. Within this model, a surgeon is in-house without elective cases and assigned for consultations and urgent operative cases on a weekly basis. This study examined the impact of a VACS model on postoperative mortality and surgeon efficiency. METHODS: This was a retrospective cohort analysis of institutional Vascular Quality Initiative data from July 2014 - July 2023. Patients undergoing lower extremity bypass, peripheral vascular intervention, or amputation were included. There was a washout period from January 2020 - January 2022 to account for COVID-19 pandemic practice abnormalities. Patients were separated into pre- or post-VACS groups. The primary clinical outcomes were 30-day and 2-year mortality. Secondary clinical outcomes included 30-day complications and 30-day and 1-year major adverse limb events (MALE). Separate analyses of operating room data from July 2017 - February 2024 and fiscal data from fiscal year 2019 - fiscal year 2024 were conducted. A washout period from January 2020 - January 2022 was applied. Efficiency outcomes included monthly relative value units (RVUs) per clinical fraction full-time equivalent (cFTE) and daytime (0730-1700, Monday-Friday) operating room minutes. Patient factors and operative efficiency were compared using appropriate statistical tests. Regression modeling was performed for the primary outcomes. RESULTS: There were 972 and 257 patients in the pre- and post-VACS groups, respectively. Pre-VACS patients were younger (66.8±12.0 vs 68.7±12.7 years, p=0.03) with higher rates of coronary artery disease (34.6% vs 14.8%, p<0.01), hypertension (88.4% vs 82.2%, p=0.01), and tobacco history (84.4% vs 78.2%, p=0.02). 30-day mortality (2.4% pre- vs 0.8% post-VACS, p=0.18) and Kaplan-Meier estimation of 2-year mortality remained stable after VACS (p=0.07). VACS implementation was not associated with 30-day mortality but was associated with lower 2-year mortality hazard on multivariable Cox regression (hazard ratio 0.5, 95% confidence interval 0.3-0.9, p=0.01). Operative efficiency improved post-VACS (850.0 [765.7, 916.3] vs 918.0 [881.0, 951.1] RVU/cFTE-month, median [inter-quartile range], p=0.03). Daytime operating minutes increased (469.1±287.5 vs 908.2±386.2 minutes, p<0.01), while non-daytime minutes (420.0 [266.0, 654.0] vs 469.5 [242.0, 738.3] minutes, p=0.40) and weekend minutes (129.0 [0.0, 298.0] vs 113.5 [0.0, 279.5] minutes, p=0.59) remained stable. CONCLUSIONS: A VACS model leads to improvement in surgeon operative efficiency while maintaining patient safety. The adoption of a vascular acute care model has a positive impact on the delivery of comprehensive vascular care.