Prognostic Value of a Classification System for Iliofemoral Stenting in Patients with Chronic Venous Obstruction.

Objective: This retrospective, multicentre study aimed to assess the prognostic value of a proposed classification system for chronic venous obstruction (CVO) patients undergoing successful interventional procedures.

Methods: This study analysed data from 13 vascular centres, including 1 033 patients with CVO treated between 2015 - 2019. The patients were classified into five category types: 1 - non-thrombotic iliac vein lesion; 2 - CVO of iliac segment; 3 - CVO of iliofemoral segment above common femoral vein confluence; 4 - CVO of iliofemoral segment extending into the femoral vein (FV) or deep femoral vein (DFV); and 5 - CVO of iliofemoral segment involving both DFV and FV. Stent deployment, complications, and follow ups were evaluated. Uni- and multivariable analyses were performed to identify predictors of primary patency loss.

Results: The mean age of the patients was 44.0 ± 14.7 years, with 59.9% being women. A median of two stents was used for unilateral cases and five stents for bilateral cases. At twelve months follow up, primary patency rates for types 1 - 5 were 94.9%, 90.3%, 80.8%, 60.6%, and 39.4%, respectively. These rates were strongly correlated with the extent of CVO and showed significant differences between each type. Univariable analysis identified predictors of primary patency loss as the type of CVO, history of deep vein thrombosis, and the total number of stents. In the multivariable analysis, the significant independent predictors of primary patency loss were the type of CVO and the total number of stents.

Conclusion: The proposed anatomical classification of iliofemoral CVO will help to predict intervention outcomes and facilitate comparison of stent outcomes in future studies. However, further evaluation and validation in prospective studies are needed to confirm the utility of this classification.