Venous thromboembolism complications after endovenous laser ablation for varicose veins and role of duplex ultrasound scan

Objective A nationwide survey was conducted in Japan to determine the incidence of venous thromboembolism (VTE) after endovenous thermal ablation for varicose veins and to investigate its pathogenic background. Methods The survey targeted all cases of endovenous thermal ablation between January 2011 and December 2013. Based on this survey, a retrospective study of patients who developed endovenous heat-induced thrombosis (EHIT) of classes 2 to 4, no EHIT-related deep venous thrombosis (DVT), and pulmonary embolism (PE) was conducted. Lower extremity venous ultrasound was performed within 72 hours and at 1 to 3 months postoperatively in all institutions. We investigated factors associated with the occurrence of complications and the usefulness of postoperative ultrasound. Results Survey responses were collected from 213 institutions. Endovenous laser ablation was performed for 43,203 patients (EHIT 2 in 318 patients, EHIT 3 in 50 patients, EHIT 4 in 7 patients, other DVTs in 24 patients, and PE in 3 patients). The incidence of VTE complications was 1.0% for EHIT 2, 0.11% for EHIT 3, 0.013% for EHIT 4, 0.063% for other DVTs, and 0.0067% for PE based on the adjusted population. Sex, age, obesity, origin of the varicose vein, vein diameter, and preoperative Caprini score were not strong indicators of VTE complications. Of 50 patients with EHIT 3, there were 35 patients who had EHIT 3 during the first postoperative ultrasound session. In one patient, EHIT 3 progressed to EHIT 4 despite initiation of anticoagulant therapy. Of seven patients with EHIT 4, only one patient had EHIT 4 at the first postoperative ultrasound examination. Because ultrasound performed before the occurrence of EHIT 4 revealed that three patients had EHIT 2 or EHIT 3, EHIT 4 could have possibly been predicted by ultrasound. Of three patients with PE, two developed PE before ultrasound, and EHIT was not detected by ultrasound in one of those patients before PE developed. Anticoagulant therapy was administered in most patients with EHIT 3 and all patients with EHIT 4 and PE, with favorable outcomes. Conclusions The incidence of VTE complications after endovenous laser ablation was low. Furthermore, the value of performing postoperative ultrasound for VTE management seems to be low because the occurrence of severe VTE complications could not be predicted by lower extremity venous ultrasound. Although the perioperative detection of VTE complications by this modality resulted in the early administration of anticoagulant therapy and may have contributed to improved prognosis, the number of those patients was limited.