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

Abstract

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.

Aortic Pathology During COVID - 19 Pandemics. Clinical Reports in Literature and Open Questions on the two Co-Occurring Conditions

“…Patients with large aneurysms (>7 cm) faced a 5.4% to 7.7% absolute increase in the probability of mortality with a delay of repair of 3 months, but demonstrated a higher probability of survival when treated with immediate endovascular repair or open surgery. Immediate endovascular repair had a higher probability of survival for smaller aneurysms (5.5 to 6.9 cm) except in settings with a high probability of COVID-19 infection (10%-30%) and advanced age (70-85 years) [15] .…”

Impact of COVID-19 on aortic operations

“…After the analysis on the habits of 23 surgeons from 18 countries, all of the participants agreed to use maximum personal protection equipment for every patient without regard to the patient's COVID‐19 status [13] . McGuinness et al [29] showed that health care providers older than 50 years have ≥0.5% chance of mortality if they contract COVID-19. It is noteworthy how this mortality rate is greater than the survival benefit in a 3-month time horizon for aneurysms.…”

“…However, regional incidence of COVID-19 and health care system status may modify these recommendations. According to McGuinness et al [29] , a 60-year-old patient has a risk of death associated with COVID-19 of about 0.6%. On the contrary, the same patient with a relatively small (5.5 to 5.9 cm) aneurysm would be exposed to a higher time-related risk of death (0.8% at 3 months and 1.9% at 6 months).…”

“…In fact, the more complex the procedure, the longer the hospital stay. It is worth noting that this would have a major impact on the risk of intrahospital infection [29] . Along the same lines, the COVID-19 outbreak limited intensive care accessibility to patients undergoing major surgery.…”

Modelling the impact of changes to abdominal aortic aneurysm screening and treatment services in England during the COVID-19 pandemic

“…A recent modelling study in the United States explored the trade-off between COVID-19 mortality and AAA-related mortality. The work focussed on the delay versus immediate repair decision for those with large AAAs, akin to considering an increased threshold for elective surgery [ 16 ]. The study uses a decision tree approach rather than the event simulation, rate-based approach used here.…”