Full subcostal subxiphoid robotic-assisted radical thymectomy: preclinical cadaveric study for optimizing patient positioning, table settings, and port configuration

Robotic subxiphoid transthoracic thymectomy showed several surgical advantages. Nevertheless, the intercostal insertion of trocars may lead to nerve injury with enhanced post-operative pain. Moreover, the dissection of peri-diaphragmatic mediastinal fat may result challenging, in particular on left side, where the presence of the heart precludes the optimal visualization. We describe a preclinical cadaveric study of a novel full subcostal robotic-assisted technique to overcome these limitations. A total subcostal robotic-assisted radical thymectomy was evaluated on a cadaver model using the da Vinci Xi system. The exploratory procedure was divided in two steps: (a) dissection of the thymus gland, except the left mediastinal epi-diaphragmatic fat pad; (b) dissection of the left diaphragmatic mediastinal fat pad avoiding heart compression while perfectly visualizing the left phrenic nerve. Five different setups were explored based on camera and trocars insertions, patient's positioning and table's settings. Both the tasks were accomplished using the novel technique. The subxiphoid insertion of the camera and the position of two robotic arms about 8 cm distally on the subcostal made the most part of mediastinal dissection straightforward. Left peri-diaphragmatic fat pad can be better visualized and dissected positioning the camera in the left subcostal port shifting the instruments on the right side. This may permit a better control of the left phrenic nerve reducing heart compression. Full subcostal robotic-assisted thymectomy resulted feasible in cadaveric model. Clinical trial should be performed to confirm the translational use of this novel technique and the speculated advantages in living model.