Platelet depletion after thoraco-abdominal aortic aneurysm endovascular repair is associated with clinically relevant hemorrhagic complications.

Abstract Introduction : thoraco-abdominal endovascular aortic repair (TA-EVAR) can be associated with platelet depletion (PD); the present study aims to evaluate PD incidence after TA-EVAR and to investigate its possible predictors and its influence on hemorrhagic complications and mortality. Methods : a retrospective analysis of all TA-EVAR from 2010 to 2021 was performed to identify patients with PD, (reduction >60%). Spontaneous hemorrhages considered were: intracranial or any hemorrhages requiring surgery. Risk factors for PD and correlation with hemorrhagic complications and 30-day mortality were investigated by uni/multivariate analysis. Results : 158 TA-EVAR were considered, 35(22%) female, 86(54%) extended TAAA (Crawford type I,II,III), 79(50%) staged procedure, 31(20%) urgent treatment (symptomatic/ruptured). PD was identified in 42 (27%) patients and correlated to female sex, thrombus-free aortic lumen >50mm, urgent treatment, extensive TAAA, blood transfusion >3 units and staged procedure at the univariate analysis. The multivariate analysis confirmed a significant correlation between PD and thrombus-free aortic lumen >50mm, urgent treatment, blood transfusion >3 units and staged procedure (OR: 2.5 (95%CI 1.03-7.0), P=.04, OR 3.2 (95% CI 1.01-8.6), P=.03, OR 3.16 (95% CI 1.23-7.7), P=.03 and OR 2.71 (95%CI 1.2-6.2), P=.04, respectively). Overall, 13 hemorrhagic complications occurred (8 intracranial and 5 peripheral); PD was associated with higher risk of hemorrhagic complications [9/42- 21% vs 4/116 - 3%, OR: 7.6 (95% CI: 2.2-26.3), P=.001] and a higher risk of 30-day mortality in elective cases 4/25 – 16% vs 3/101 – 3%, OR: 6.2 (95%CI: 1.3 -29.8), P=.03. Conclusion : PD is a relatively common event after TA-EVAR and is associated with thrombus-free aortic lumen >50mm, urgent treatment, blood transfusion >3 unit and staged procedure. Hemorrhagic complications and mortality are increased under these circumstances.