Residual popliteal vein thrombosis after endovascular treatment of mixed-type lower extremity deep vein thrombosis is relevant to post-thrombotic syndrome.

Objective: Patients with mixed-type lower extremity deep vein thrombosis (LEDVT) have a higher incidence of post-thrombotic syndrome (PTS) following endovascular treatment (EVT). This study aimed to identify risk factors associated with PTS in these patients post-EVT.

Methods: This retrospective study included patients diagnosed with acute mixed-type LEDVT who underwent EVT between January 2020 and December 2022. Patient assessments were conducted using ultrasound and the Villalta scale. Baseline characteristics, management details, and follow-up findings were compared between patients who developed PTS and those who did not at six months after EVT. Cox regression and nomogram analyses were performed to identify risk factors associated with the development of PTS.

Results: The study enrolled 118 patients, of which 103 completed the follow-up. Among them, 24.3% developed post-thrombotic syndrome (PTS) within six months. Significant differences between the PTS and non-PTS groups were found concerning residual thrombosis in the popliteal, common femoral, and femoral veins. Multivariate Cox regression analysis indicated that residual popliteal vein thrombosis (RPVT) (HR 4.93, 95% CI 1.61-15.11) and preoperative iliac vein stenosis (HR 3.21, 95% CI 1.11-9.33) were significant risk factors for PTS. Additionally, subgroup analysis for preoperative iliac vein stenosis and sensitivity analysis confirmed that RPVT remained a risk factor for PTS (HR 4.48, 95% CI 1.27-15.84).

Conclusion: Our study demonstrated a positive association between residual popliteal vein thrombosis (RPVT) and PTS in patients with extensive mixed-type LEDVT after EVT. These findings suggest that intensive monitoring and aggressive therapeutic interventions may be required for patients with RPVT to reduce the risk of PTS.