Post-Hoc Analysis of a Multicenter Clinical Trial: Correlation of Coagulation Factor Changes and MRI-Defined...

Background/Objectives: 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. Methods: 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. Results: Between January 2021 and April 2023, 44 patients underwent EO-based PS. Based on a ≥ 20% VM volume reduction, patients were classified into "achieved" (n = 26; 59.1%) and "non-achieved" (n = 18; 40.9%) groups. D-dimer levels significantly increased on postoperative day 1 (POD1) compared with pretreatment screening (p < 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/cm³; Spearman's ρ = 0.43, p = 0.03). The non-achieved group showed significantly higher D-dimer elevation than the achieved group (p = 0.03). Conclusions: 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.