Risk factors for endovenous heat-induced thrombosis after endovenous radiofrequency ablation performed in Thailand

Objective: We aimed to determine the incidence of and associated risk factors for endovenous heat-induced thrombosis (EHIT) after endovenous radiofrequency ablation (RFA). Methods: We retrospectively reviewed the medical records of 82 patients with 97 great saphenous veins undergoing RFA from 2012 to 2014. Results: The incidence of EHIT was 10.3%. Class 1, 2, and 3 EHIT was found in 50%, 30%, and 20% of legs, respectively. No class 4 EHIT, deep vein thrombosis, or pulmonary emboli occurred. Univariate analysis revealed that the associated risk factors for EHIT were a vein diameter of >10 mm, operative time of >40 min, and Caprini score of >6. Multivariate analysis revealed that the independent risk factors associated with EHIT were a vein diameter of >10 mm and operative time of >40 min. Conclusions: A vein diameter of >10 mm and operative time of >40 min might be predictive factors for EHIT following RFA.