AB026. Contralateral pleura-sparing modified subxiphoid approach for robotic thymectomy: operative results, and advantages in metachronous lung cancer resection

Background: Robotic thymectomy for thymic epithelial tumors (TETs) yields favorable perioperative results and effective disease control. The lateral approach is commonly employed for robot-assisted thymectomy, while the subxiphoid approach offers another option for robotic thymectomy. However, the subxiphoid approach necessitates bilateral pleural resection, which may lead to unfavorable conditions, such as bilateral pneumothorax and the bilateral dissemination of tumors. To mitigate this risk, we utilize the subxiphoid method along with three additional robotic ports on the hemithorax, referred to as the “modified subxiphoid approach”. We aimed to assess the clinical outcome and the advantage of this procedure using our clinical data.

Methods: We retrospectively reviewed patients who underwent modified subxiphoid robotic thymectomy for TETs at Nishi-Kobe Medical Center from September 1, 2019, to December 31, 2024. We evaluated the surgical results and elucidated the cases that underwent lung cancer resection after thymectomy.

Results: A total of 21 patients were eligible for this study. The mean age was 65.3 [44–81] years. The breakdown of diseases is as follows: thymoma without myasthenia gravis (MG), 15; thymoma with MG, 4; and thymic cancer, 2. The mean tumor diameter was 44.6 [13–100] mm. The operative side was right in 13 cases and left in 8 cases. No major morbidity occurred. R0 resection was achieved in 20 cases. A microscopic positive margin was found in the largest tumor case, which recurred 36 months later as ipsilateral pleural disseminations. No other recurrences or patient deaths occurred during the follow-up (median 24 months, range, 6–65 months). The 3-year recurrence-free survival rate was 85.7%. Lung cancer was detected in 3 cases after thymectomy, with ipsilateral lung resection performed in 1 case and contralateral lung resection in 2 cases. Adhesion to the vascular was found in the ipsilateral case, while no adhesion was found in the contralateral cases. In the case of the patient with MG who underwent contralateral lung resection, the operative findings revealed a complete resection of the contralateral thymus, except for the fat above the diaphragm.

Conclusions: The contralateral pleura-sparing modified subxiphoid approach is an acceptable and safe method, particularly given the advantage of metachronous lung resection. A large tumor should be avoided due to the risk of unresectability and recurrence.

Keywords: Robotic thymectomy; contralateral pleura-sparing modified subxiphoid approach; metachronous lung resection