Factors Influencing the Incidence of Endovenous Heat-Induced Thrombosis (EHIT)

Introduction: Extension of thrombus from the great saphenous vein into the common femoral vein can be an early postprocedural complication of endothermal ablation (ETA). Methods: A retrospective review was performed over a 3-year period. Intraprocedural ultrasound images demonstrating the distance of the catheter tip to the saphenofemoral junction (SFJ) were available for 519 procedures, and this distance was measured. Results: Twenty-one (4.0%) cases of endovenous heat-induced thrombus (EHIT) were diagnosed. In all, 15 (6.4%) EHITs occurred following endovenous laser ablation and 6 (2.1%) after radiofrequency (P = .02). Distance from catheter tip to SFJ, vein diameter, concomitant treatments, and perioperative anticoagulation were not significant risk factors for EHIT. Of the clinical factors assessed, gender (P = .002), Clinical, Etiologic, Anatomic and Pathophysiologic classification 3 to 6 (P = .003), history of prior thrombosis (P = .04), and Caprini thrombosis risk factor assessment score (P = .004) were significant. On multivariate analysis, Caprini score (P = .0002) and male gender (P = .0003) remained significant. Conclusions: Male gender and increased Caprini score are predictive factors for EHIT following ETA.