Strategies to Reduce Rates of Severe Endothermal Heat-induced Thrombosis Following Radiofrequency Ablation.

OBJECTIVE: Endothermal heat-induced thrombosis (EHIT) is a potential complication of radiofrequency ablation (RFA). Data on effective prophylaxis of EHIT is limited. In 2018, a high-volume single institution implemented strategies to decrease the incidence of EHIT, including a single peri-procedural prophylactic dose of low molecular weight heparin (LMWH) to patients with a great saphenous vein (GSV) diameter ≥8mm or sapheno-femoral junction (SFJ) diameter ≥10mm, and limiting treatment to one vein per procedure. The size threshold was derived from existing literature. The study objective was to evaluate the impact of these institutional changes on thrombotic complication rates after RFA.

METHODS: A retrospective cohort control study was conducted using the Vascular Quality Initiative (VQI) database. Data was collected for patients who underwent RFA with a GSV diameter ≥8 mm or SFJ diameter ≥10mm from January 2015-July 2022. Clinical endpoints were thrombotic complications (thrombophlebitis, EHIT or DVT) and bleeding complications. Patient demographic and procedural variables were included in the analysis and significant variables after univariable logistic regression were included in a multiple variable logistic regression.

RESULTS: Post-policy change, the overall vein center EHIT rate decreased from 2.6% to 1.5% with a trend toward significance (p = 0.096). The inclusion criteria of GSV diameter ≥8mm or SFJ diameter ≥10mm yielded 845 patients, of which 298 were treated prior to the policy change and 547 were treated after. There was a significant reduction in rates of EHIT classified as class III or greater (2.34 vs 0.366, p = 0.020) following the institutional changes. Treatment of two or more veins and increased vein diameter were associated with increased risk of EHIT (p = 0.049; <0.001). There was no significant association between peri-procedural anticoagulation and all-cause thrombotic complications or EHIT (p = 0.563; 0.885).

CONCLUSIONS: The institutional policy changes have led to lower rates of EHIT, with a reduction in severe EHIT rates in patients with ≥8mm diameter GSV or ≥ 10mm SFJ treated with RFA. Of the changes implemented, restricting treatment to one vein is associated with reduction in severe EHIT. There is no association with peri-procedural LMWH, though a Type 2 error may be occurring. Alternative strategies to prevent thrombotic complications should be explored, such as increasing the dosage and duration of peri-procedural anticoagulation, antiplatelet use, and nonpharmacologic strategies.