Mechanical thrombectomy: Long-term risk for venous thromboembolism recurrence

Abstract Introduction Venous thromboembolism (VTE) represents a major cause of cardiovascular morbidity, with mechanical thrombectomy (MT) increasingly used to treat arterial and venous thromboembolism for rapid symptom relief and prevention of post-thrombotic syndrome. However, long-term effects on VTE recurrence remain unclear. MT may paradoxically increase VTE risk through unavoidable endothelial damage, incomplete thrombus removal, and coagulation cascade activation. Critically, venous and arterial systems differ in hemodynamic environments and endothelial characteristics, with venous systems having lower flow velocities and greater susceptibility to stasis-mediated thrombosis. We hypothesized that venous MT would be associated with higher VTE recurrence compared to arterial MT due to a greater propensity for stasis-mediated thrombosis in damaged venous segments with inherently prothrombotic microenvironments. Methods We retrospectively analyzed 337 consecutive adult patients undergoing MT at a single center from July 2023 to December 2024. The primary outcome was time to first VTE recurrence, assessed using Kaplan-Meier analysis and compared between arterial and venous MT groups via log-rank test. Cox regression evaluated predictors of recurrence adjusting for age, sex, race, body mass index, Charlson comorbidity index, and anticoagulant use. Repeated recurrences and competing risks analyses were also performed. Statistical analyses were performed using Stata. Results VTE recurrence occurred in 9% (29/337) of patients—3% (9/263) after arterial MT and 27% (20/74) after venous MT (p < 0.0001). At 500 days, recurrence risk exceeded 35% post-venous MT versus 4% post-arterial MT. Patients undergoing venous MT were younger (62±16.4 vs. 68±13.5 years; p=0.0065) and had higher BMI (30.5±8.8 vs. 27.8±6.7; p=0.015). Venous MT was the sole significant predictor of recurrence (hazard ratio 8, 95% CI 1.9–34). Recurrence occurred at the original MT site in 23% versus 3% of venous versus arterial MT patients (p<0.001), suggesting localized endothelial dysfunction. DOAC [Xa inhibitor] use did not reduce recurrence risk in either group. Repeated recurrence and competing risk analyses confirmed these findings. Mortality was higher after arterial MT (16%) than venous MT (7%) (p<0.04), likely reflecting acute arterial syndrome severity. Conclusions This study is the first to demonstrate that venous MT is associated with a substantially increased risk of long-term VTE recurrence despite short-term procedural benefits, with an 8-fold increased hazard and over one-third experiencing recurrence by 500 days. The lack of efficacy of factor Xa inhibitor DOACs suggests a need for evaluation of alternative anticoagulants, including direct thrombin inhibitors and extended follow-up strategies. These findings have immediate clinical implications, underscoring the importance of enhanced long-term surveillance and tailored thromboprophylaxis after venous MT. The substantial recurrence risk must be balanced against acute procedural benefits in clinical decision-making. Prospective studies are needed to clarify underlying mechanisms, optimize anticoagulation regimens, and develop evidence-based surveillance protocols to minimize long-term thrombotic risk while preserving acute clinical benefits.