Post-Hoc Analysis of a Multicenter Clinical Trial: Correlation of Coagulation Factor Changes and MRI-Defined Treatment Outcomes After Sclerotherapy for Venous Malformations.

The therapeutic efficacy of percutaneous sclerotherapy (PS) for venous malformations (VMs) based on volumetric magnetic resonance imaging (MRI) measurements and its association with early post-treatment coagulation markers remains unexplored. This study evaluates the therapeutic efficacy of 5% monoethanolamine oleate (EO)-based PS in treating difficult-to-resect VMs using volumetric MRI and investigates its association with early changes in coagulation markers. This post-hoc analysis utilized data from a prospective, open-label, multicenter clinical trial initiated on 1 January 2021. The correlation between MRI-determined volume reduction and post-sclerotherapy changes in coagulation markers was assessed. Between January 2021 and April 2023, 44 patients underwent EO-based PS. Based on a ≥ 20% VM volume reduction, patients were classified into "achieved" ( = 26; 59.1%) and "non-achieved" ( = 18; 40.9%) groups. D-dimer levels significantly increased on postoperative day 1 (POD1) compared with pretreatment screening ( < 0.001), whereas fibrinogen and prothrombin international normalized ratio levels remained unchanged. In the achieved group, a significant correlation was observed between the volume reduction rate and the administered EO dose per lesion volume (mL/cm; Spearman's ρ = 0.43, = 0.03). The non-achieved group showed significantly higher D-dimer elevation than the achieved group ( = 0.03). This is the first multicenter study to evaluate EO-based PS efficacy for VMs using volumetric MRI and explore its relationship with early post-treatment coagulation markers. Elevated D-dimer levels on POD1 were not predictive of treatment efficacy, highlighting their limited clinical utility in assessing therapeutic response.