Impact of hemodynamic doppler ultrasound parameters on patency and post-thrombotic syndrome in patients with iliofemoral venous stents.

Chronic venous obstruction affects thousands worldwide and may lead to severe long-term complications such as post-thrombotic syndrome (PTS), marked by pain, swelling, skin changes, and venous ulcers. Endovenous stenting has become a cornerstone in restoring venous outflow, yet surveillance strategies to detect stent dysfunction early remain unstandardized. Doppler ultrasound (DUS), widely available and non-invasive, holds potential as a monitoring tool, but lacks validated markers to guide long-term follow-up. In this retrospective study of 161 patients and over 1,100 DUS assessments, we examined the predictive value of hemodynamic parameters for stent dysfunction and PTS. Stent patency was assessed using DUS or CT venography, and PTS was defined by a Villalta score ≥ 5 at last follow up. Hemodynamic parameters were compared using univariate and multivariable logistic regression models. Significant stent stenosis or occlusion (≥ 50%) was more common in younger patients (mean age 37.7 vs. 48.2 years, p = 0.003), with risk increasing by 4.4% per year decrease in age (OR = 1.044, p = 0.008). Loss of respiratory modulation was strongly associated with stent dysfunction (p < 0.001). Patients who had PTS at last follow up, had lower venous flow (297 vs. 463 mL/min, p = 0.047), reduced peak velocity (p = 0.003), and impaired respiratory modulation (p = 0.017). These findings support using DUS-derived parameters for early, non-invasive detection of stent-related complications to improve long-term patient outcomes.