Non-thermal venous endothelial injury by microsecond irreversible electroporation: mechanisms of apoptosis, oxidative stress, and vascular closure initiation.

Introduction: Minimally invasive treatments for lower extremity varicose veins carry risks of thermal diffusion injury, nerve damage, ectopic embolism, and limited efficacy, highlighting the need for safer venous closure techniques. Microsecond irreversible electroporation (IRE) is a non-thermal ablation method whose mechanism of action on venous endothelium remains unclear. Methods: Using human umbilical vein endothelial cells (HUVECs) and a porcine hepatic portal vein model, we evaluated the killing efficacy, mechanism of action, and in vivo pathological changes induced by microsecond IRE at varying parameters. Results: IRE killed venous endothelial cells in a parameter-dependent manner: apoptosis predominated at 400 V/cm, while necrosis predominated at 800 V/cm with high pulse counts. IRE activated the intrinsic apoptotic pathway via reduced mitochondrial membrane potential, elevated ROS, and calcium overload, while promoting release of DAMPs (ATP, HMGB1, vWF). In the porcine portal vein model, IRE induced early inflammatory and microthrombotic changes while preserving overall vascular wall architecture. Discussion: Microsecond IRE achieves controllable, non-thermal venous endothelial injury and initiates signals necessary for venous closure, providing preclinical evidence for its development as a novel endovascular treatment for varicose veins.