[Thymomectomy by minimally invasive surgery. Comparative study videosurgery versus robot-assisted surgery]

To report the results of minimally invasive surgery in patients with stage I or II thymoma in the Masaoka classification. The reference technique is partial or complete thymectomy by sternotonomy.

A retrospective single-center study of a prospective database including all cases of thymoma operated from April 2009 to February 2015 by minimally invasive techniques: either videosurgery (VATS) or robot-assisted surgery (RATS). The surgical technique, type of resection, length of hospital stay, postoperative complications and recurrences were analysed.

Our series consisted of 22 patients (15 women and 7 men). The average age was 53 years. Myasthenia gravis was present in 12 patients. Eight patients were operated on by VATS and 14 patiens by RATS. There were no conversions to sternotomy and no perioperative deaths. The mean operating time was 92min for VATS and 137min for RATS (P<0.001). The average hospital stay was 5 days. The mean weight of the specimen for the VATS group was 13.2 and 45.7mg for the RATS group. Twelve patients were classified Masaoka stage I and 10 were stage II. According to the WHO classification there were 7 patients type A, 5 type AB, 4 type B1, 4 type B2 4 and 2 type B3. As proposed by the Group ITMIG-IASLC in 2015 all patients corresponded to group I. The mean follow-up period was 36 months. We noted 3 major perioperative complications according to the Clavien-Dindo classification: one pneumonia, one phrenic nerve paralysis and one recurrent laryngeal nerve palsy. We observed one case of local recurrence at 22 months. Following surgery 4 patients were treated with radiotherapy and 2 patients with chemotherapy.

The minimally invasive route is safe, relatively atraumatic and may be incorporated in the therapeutic arsenal for the treatment of Masaoka stage I and II thymoma as an alternative to conventional sternotomy. RATS and VATS are two minimally invasive techniques and the results in the short and medium term are acceptable. The clinical advantages of one over the other are sifficult to establish. RATS could handle larger and more complex lesions in view of the weight and size of the operating instrument.