The safety of thymic vein sealing with ultrasonic energy in video-assisted thoracoscopic surgery thymectomy

Extended thymectomy is the main surgical treatment for myasthenia gravis and thymoma. Since Watanabe et al. and Blalock et al. reported the first case of thymectomy with median sternotomy in the treatment of myasthenia gravis in 1939, median sternotomy thymectomy has gradually become the standard operation for myasthenia gravis and thymoma (1,2), In 2002, Hsu reported the first case of thymectomy by video-assisted thoracoscopic surgery (VATS) (3). Thymectomy is also needed for thymic tumors. For thymectomy, the protection of the phrenic nerve, the dissociation of the innominate vein, and the management of thymic veins are the key points. It is reported that 67% of thymic veins originate from the left innominate vein, 14.7% from the right innominate vein, 11.5% from the inferior thyroid vein, and 6.6% from the superior vena cava. Most of the thymic veins are located behind the thymus. The number of thymic veins fluctuates from 1 to 3, and single thymic veins are common (83.6%) (4,5). The traditional treatment of a thymic vein is to cut off the distal and proximal end of the thymic vein after clamping the Ham-Lock separately. Beginning in 2016, our team has effectively used an ultrasound scalpel to cut off thymic veins in open surgery. Thereafter, we have applied this method in thoracoscopic thymectomy, and there has been no conversion to open operation, intraoperative massive hemorrhage, post-operative hemorrhage, and secondary operation. The characteristics of patients and operative data of 169 patients undergoing thymectomy in our department were retrospectively analyzed to evaluate the safety of the transection of thymic veins by ultrasonic energy in thymectomy under video-assisted thoracoscopy