Investigation of Venous Vascular Occlusion Mechanisms in the Great Saphenous Vein Treated with Radiofrequency Endovenous Ablation for Varicose Veins in Clinical Cases

Objective: We assessed the mechanism of venous vascular occlusion in the great saphenous vein (GSV) following radiofrequency venous ablation (RFA) in clinical cases of varicose veins. Materials and Methods: RFA was performed on 35 limbs from 25 patients presenting with symptomatic varicose veins and GSV incompetence. Immediately following RFA, a portion of the highly ligated GSV was pathologically examined. The venous segments were stained and examined microscopically using hematoxylin (eosin) and Masson’s trichrome staining. Post-procedure, the condition of the ablated GSV, including vascular properties, thrombus presence, and blood flow status, was analyzed using duplex scanning of the lower extremities. Results: Major complications such as thrombophlebitis or skin burns were not observed during RFA. Histological damage beyond the endothelial layer of the vessel wall was observed in all treated varicose veins. In the veins treated with RFA, intima edema was noted in 85.7% of the cases, and microthrombus in 88.6%. Postoperative duplex ultrasound was performed in all cases between days 7 and 59 (median, 21.2 ± 19 days). Intravascular thrombi were present in all cases, with intimal hyperplasia in 80.0%. Complete occlusion of the entire GSV was not observed. Postoperative duplex scanning revealed blood flow through the perforating branches of the varicose veins in 14 limbs (40.0%); when scanning lower extremities, it showed intravascular thrombi in all cases and vessel intima thickening in 80.0% of cases. Conclusion: Although changes were identified in the vascular tissue due to RFA, no vascular occlusion was observed. During the post-cautery course, thrombosis of the ablated blood vessels was observed in nearly all cases, likely causing blood flow obstruction.