Impact of Endovascular Treatment on the Development of Post-Thrombotic Syndrome in Iliac and Iliofemoral Deep Vein Thrombosis

<b>Background:</b> Post-thrombotic syndrome (PTS) is a frequent complication of deep vein thrombosis (DVT), with significant clinical and quality-of-life implications. Endovascular techniques have emerged as potential strategies to reduce PTS severity in selected patients, though evidence remains inconclusive. <b>Methods:</b> We conducted a multicenter, retrospective study including 176 patients with iliac or iliofemoral DVT from four hospitals in Murcia, Spain. Patients were treated either with anticoagulation alone (<i>n</i> = 121) or with endovascular techniques followed by anticoagulation (<i>n</i> = 55). The primary outcome was the presence of PTS at 12 months, defined by the presence of ≥5 signs/symptoms from the Villalta scale. Multivariate analysis was performed to identify independent predictors of PTS. <b>Results:</b> No significant differences were observed in the overall prevalence of PTS between the endovascular and anticoagulation-only groups at 12 months (25.4% vs. 23.2%, <i>p</i> = 0.63). However, edema and skin hyperpigmentation were significantly more frequent in the anticoagulation-only group. Patients treated with endovascular techniques had lower rates of residual thrombosis at follow-up (34.6% vs. 53.9%, <i>p</i> = 0.03). Multivariate analysis identified residual thrombosis (OR 6.3, 95% CI 2.74-14.5), persistently elevated D-dimer (OR 3.26, 95% CI 1.1-9.7), and age (OR 1.02, 95% CI 1.003-1.042) as independent predictors of PTS. Mortality was significantly higher in the anticoagulation-only group, largely driven by a higher cancer prevalence. <b>Conclusions:</b> Endovascular techniques did not significantly reduce the overall incidence of PTS but were associated with lower rates of specific signs such as edema and hyperpigmentation. Residual thrombosis remains a key predictor of PTS and may represent a modifiable therapeutic target.