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 (DVT) have a higher incidence of post-thrombotic syndrome (PTS) after endovascular treatment (EVT). This study aimed to identify risk factors associated with PTS in these patients after EVT. METHODS: This retrospective study included patients diagnosed with acute mixed-type lower extremity DVT who underwent EVT between January 2020 and December 2022. Patient assessments were conducted using ultrasound examination 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 6 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 6 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) (hazard ratio [HR], 4.93; 95% confidence interval [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). CONCLUSIONS: Our study demonstrated a positive association between RPVT and PTS in patients with extensive mixed-type lower extremity DVT after EVT. These findings suggest that intensive monitoring and aggressive therapeutic interventions may be required for patients with RPVT to decrease the risk of PTS.