Article Abstract

Minimally invasive surgery for thymic epithelial tumors: a single institutional experience

Authors: Hideyuki Maeda, Tamami Isaka, Shota Mitsuboshi, Sayaka Katagiri, Kei Sakamoto, Hiroe Aoshima, Takuma Kikkawa, Takako Matsumoto, Kunihiro Oyama, Masahide Murasugi, Masato Kanzaki


Background: Minimally invasive surgery (MIS) is increasing to become the preferred surgical approach for anterior mediastinal tumors. This study reported our experience with MIS including video-assisted thoracoscopic surgery (VATS) and robot-assisted thoracoscopic surgery (RATS) for thymic epithelial tumors and compared the surgical results of MIS with those of conventional approaches (CAs).
Methods: Between March 2001 and December 2014, 129 patients underwent surgical treatment for thymic epithelial tumors at authors’ institute. Fifty-nine patients underwent MIS including VATS and RATS (MIS group) and 70 patients underwent CA such as median sternotomy and thoracotomy (CA group). The clinical outcomes between two groups were compared.
Results: The surgical procedures in MIS group included extended thymectomy in 8, total thymectomy in 4, right hemi-thymectomy in 24, and left hemi-thymectomy in 23 patients. The surgical procedures in CA group included extended thymectomy in 11, total thymectomy in 56, right hemi-thymectomy in 2, and left hemi-thymectomy in 1 patient. The mean tumor size was 35.6 mm in MIS group and 49.2 mm in CA group. The tumor size in MIS group was significantly smaller than CA group (P=0.0011). The number of patients with MG was 9 (15.3%) in VATS group and 11 (15.7%) in CA group, with no significant difference. The operating time, blood loss, duration of drainage, and length of hospital stay in MIS group were significantly less than those in CA group (P<0.0001). There were no perioperative complications in MIS group. The operative mortality rate was 0% in MIS group, 1.4% in CA group. The tumor histology in MIS group was thymoma in 22, thymic cancer in 5, thymic cyst in 29, and thymic lipoma in 3 patients. In CA group, the tumor histology was thymoma in 57; thymic cancer in 8, thymic cyst in 4, and thymic lipoma in 1 patient. No recurrence was observed in MIS group but 5 patients in CA group had recurrence. In MIS group, 9 patients underwent RATS. There were extended thymectomy in 3, total thymectomy in 4, and hemi-thymectomy in 2 patients. The mean tumor size was 32.8±18.3 mm in RATS. Patients with MG were 3 (33.3%). The mean operative time, blood loss, duration of drainage, and length of postoperative stay were 204.3±55.4 min, 44.1±71.9 mL, 1.6±0.5 days, and 7.0±0.9 days, respectively. The tumor histology in RATS was thymoma in 5 and thymic cyst in 4 patients. No conversion to VATS or CA occurred. There were no perioperative complications in RATS.
Conclusions: This study showed MIS was feasible and safe for thymic epithelial tumors. MIS including RATS can be standard surgical treatment of anterior mediastinal tumors.