A novel method of subxiphoid video-assisted thoracic surgery for thymectomy

Background: With advances in thoracoscopic surgical instruments and techniques, subxiphoid video-assisted thoracic surgery (S-VATS) has become the main approach for anterior mediastinal tumor resection under thoracoscopy. However, the drawbacks of S-VATS, including it being a relatively unfixed surgical procedure, make it complicated and difficult for unexperienced surgeons to master.

Methods: This study retrospectively reviewed and analyzed consecutive patients with anterior mediastinal tumor or myasthenia gravis (MG) who underwent S-VATS at the Fujian Medical University Union Hospital, China, between March 2015 and April 2019.Patients were divided into the conventional group and the "four-zone one-way" group. Intraoperative and postoperative variables were compared between the groups. Cumulative sum (CUSUM) analysis was applied to determine the operation time (OT)-learning curve of the S-VATS "four-zone one-way" method.

Results: A total of 82 patients were included in this analysis, of which, 40 patients underwent the conventional method of S-VATS and 42 patients underwent the "four-zone one-way" method. Patients in the "four-zone one-way" group had significantly shorter OT (138.50±29.43 and 118.00±28.18 minutes, respectively; P=0.002) and significantly less blood loss (36.00±20.16 and 23.92±14.96 mL, respectively; P=0.003) compared with patients in the conventional group. Our data indicated that there was no difference of the efficacy of MG treatment between the 2 groups. The difference in the preoperative and postoperative quantitative MG scoring system score (QMG-score) and the dose reduction of cholinesterase inhibitors was comparable between patients in the 2 groups. According to the CUSUM analysis curve, after a steady improvement over phase I (cases 1-12 for the traditional method and cases 1-5 for the "four-zone one-way" method), the surgical procedure could be mastered. Phase III occurred after case 26 in the traditional group and case 28 in the "four-zone one-way" group, and is characterized by rapid improvements.

Conclusions: Compared with the conventional method of S-VATS, the "four-zone one-way" method significantly decreased OT and estimated blood loss. These results demonstrated the feasibility and safety of the "four-zone one-way" method of S-VATS.