Distance to Junction and Small Saphenous Vein Treatment Drive Risk of ≥Grade 2 Endothermal Heat-Induced Thrombosis in Multicenter Practice

Ablation distance is the dominant determinant of EHIT grade ≥2, with risk rising as distance shortens, particularly in SSV cases. Model-based estimates aligned with real-world event rates, and a simple two-variable approach using distance and SSV provided strong discrimination. These findings support procedural strategies that prioritize securing adequate distance, especially when treating the SSV.