Reassessing the operative threshold for abdominal aortic aneurysm repair in the context of COVID-19

McGuinness, Brandon; Troncone, Michael; James, Lyndon P.; Bisch, Steve; Iyer, Vikram

OBJECTIVE: The worldwide pandemic involving the novel respiratory syndrome (COVID-19) has forced healthcare systems to delay elective operations, including abdominal aortic aneurysm (AAA) repair, to conserve resources. This study provides a structured analysis of the decision to delay AAA repair and quantify the potential for harm. METHODS: A decision tree was constructed modeling immediate repair of AAA relative to an initial non-operative (delayed repair) approach. Risk of COVID-19 contraction and mortality, aneurysm rupture, and operative mortality were considered. A deterministic sensitivity analysis for a range of patient ages (50 to >80), probability of COVID-19 infection (0.01%-30%), aneurysm size (5.5->7cm), and time horizons (3-9 months) was performed. Probabilistic sensitivity analyses (PSA) were conducted for three representative ages (60, 70, 80). Analyses were conducted for endovascular aortic aneurysm repair (EVAR) and open surgical repair (OSR). RESULTS: Patients with aneurysms 7cm or greater demonstrated a higher probability of survival when treated with immediate EVAR or OSR, compared to delayed repair, for patients under 80 years of age. When considering EVAR for aneurysms 5.5-6.9cm, immediate repair had a higher probability of survival except in settings with high probability of COVID-19 infection (10-30%) and advanced age (70-85+ years). A non-operative strategy maximized the probability of survival as patient age or operative risk increased. Probabilistic sensitivity analyses demonstrated that patients with large aneurysms (>7cm) faced a 5.4-7.7% absolute increase in the probability of mortality with a delay of repair of 3 months. Young patients (60-70 years) with 6-6.9cm aneurysms demonstrated an elevated risk of mortality (1.5-1.9%) with a delay of 3 months. Those with 5-5.9cm aneurysms demonstrated an increased survival with immediate repair in young patients (60), however this was small in magnitude (0.2-0.8%). The potential for harm increased as length of surgical delay increased. For elderly patients requiring OSR, in the context of endemic COVID-19, delay of repair improves probability of survival. CONCLUSION: The decision to delay operative repair of AAA should consider both patient age and local COVID-19 prevalence in addition to aneurysm size. EVAR should be considered when possible due to a reduced risk of harm and lower resource utilization.