Pre-operative Color Doppler Ultrasonography Predicts Endovenous Heat Induced Thrombosis after Endovenous Radiofrequency Ablation.

OBJECTIVES: The aim was to identify pre-operative color Doppler ultrasound (CDUS) variables predictive of post-operative endovenous heat induced thrombosis (EHIT) after radiofrequency ablation (RFA) of the saphenous veins.

DESIGN: This was a single centre, observational study with retrospective analysis of consecutive patients treated from December 2010 to February 2017.

MATERIALS AND METHODS: Pre-operatively, the diameter of the sapheno-femoral junction (dSFJ), distance between epigastric vein and SFJ (dEV-SFJ), maximum great saphenous vein (GSV) diameter (mdGSV), diameter of the saphenous-popliteal junction (dSPJ), and mean small saphenous vein (SSV) diameter (adSSV) were measured. All patients received low molecular weight heparin (LWMH) at a prophylactic dose for a week. Post-operatively, CDUS was performed after 72 h, 1 week, and 3 months.

RESULTS: Venous interventions on 512 patients were performed: 449 (87.7%) underwent RFA of the GSV (Group 1), and 63 (12.3%) of the SSV (Group 2). At Day 3 post-operatively, CDUS documented 100% complete closure of the treated saphenous vein segment. Overall, 40 (7.8%) cases of post-operative EHIT were identified: 29 in Group 1, and 11 in Group 2 (6.4% vs. 17.5%, p = .005). Deep venous thrombosis or pulmonary embolism did not occur in either group. At the 1 month follow up, all cases of EHIT regressed. In Group 1, on multivariate analysis, dEV-SFJ (OR, 1.13, p = .036; 95% CI 1.01-1.27) was the only statistically significant predictor for EHIT. A dEV-SFJ distance of 4.5 mm yielded an 84% of sensitivity for EHIT prediction with a 72.4% positive predictive value. In Group 2, univariate analysis did not identify independent risk factors for EHIT occurrence.

CONCLUSIONS: EHIT was higher than previously reported. The dEV-SFJ was the most significant predictor for EHIT in the GSV group. A greater distance between the tip of the radiofrequency catheter and the SFJ may decrease the risk of developing this complication.