Platelet Depletion after Thoraco-Abdominal Aortic Aneurysm Endovascular Repair is Associated with Clinically Relevant Hemorrhagic Complications

Background: 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, correlation with hemorrhagic complications and 30-day mortality were investigated by uni/multivariate analysis. Results:A total of 158 TA-EVAR were considered, 35(22%) female, 86(54%) extended thoraco-abdominal aortic aneurysm (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 (odds ratio [OR]: 2.5 (95% confidence interval [CI] 1.03–7.0), P = 0.04, OR 3.2 (95% CI 1.01–8.6), P= 0.03, OR 3.16 (95% CI 1.23–7.7), P = 0.03 and OR 2.71 (95% CI 1.2–6.2), P= 0.04, 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= 0.001) 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= 0.03. Conclusions:PD is a relatively common event after TA-EVAR and is associated with thrombus-free aortic lumen > 50mm, urgent treatment, blood transfusion > 3 units and staged procedure. Hemorrhagic complications and mortality are increased under these circumstances.