Robotic resection of mediastinal masses: a decade of experience

Background: Robotic-assisted surgery is gaining an increasing popularity in the past decades within the field of thoracic surgery, especially in mediastinal tumor resection. In the narrow space of the mediastinum surrounded by a complexity of anatomical structures, robotic-assisted thoracic surgery (RATS) shows its potential due to its enhanced dexterity, the three-dimensional view with great maneuverability and tremor adjustment in comparison to other minimal invasive techniques. Primary resection is the therapy of choice for most common mediastinal masses in the anterior (thymoma) and posterior (neurogenic tumors) mediastinum. Methods: We retrospectively analyzed all robotic-assisted mediastinal tumor resections performed at the Inselspital, Bern University Hospital, between September 2010 and October 2020 from our anonymized database. Resections were performed using the da Vinci robotic platform (Intuitive Surgical, Sunnyvale, CA, USA). Results: In total, 124 robotic-assisted resections of mediastinal tumors were performed. One hundred twelve tumors were located in the anterior, one in the middle and eleven in the posterior mediastinum. Thymomas (n=37) and thymic hyperplasias (n=34) have been accountable for 63.39% of all mediastinal masses in the anterior compartment, whereas neurogenic tumors, including schwannoma (n=5), ganglioneuroma (n=2) and neurofibroma (n=1), have been the most common tumors (72.73%) in the posterior mediastinum. Complete resection was achieved in 96.77% (n=120) of cases with an overall conversion rate of 0.81% (n=1). Mean size of resected mediastinal tumors in the anterior mediastinum was 5.16 +/- 3.41 and 5.08 +/- 2.88 cm for tumors in the posterior mediastinum. For all robotic-assisted mediastinal tumor resections mean length of hospital stay (LOS) was 3.45 +/- 2.95 days and complications occurred in 12.90% of patients (n=16), with no statistically significant relationship between the different compartments (P=0.68). Postoperative 30- and 90 -day mortality rate was 0.00%. Mean follow-up for patients with thymoma, thymic carcinoma, teratoma and metastasis of other cancer (n=44) was 40.00 +/- 34.55 months and 5 -year follow-up was reached in 34.09% (n=15) of these cases. For these patients, 5 -year recurrence-free survival (RFS) was 86.67% and 5 -year overall survival (OS) was 100%. Conclusions: Robotic-assisted thoracoscopic surgery has emerged as a promising technique for minimally invasive resection of mediastinal masses. RATS is combining the advantages of video-assisted thoracic surgery (VATS) while overcoming its limitations. Robotic-assisted resection offers a safe and feasible minimally invasive approach for mediastinal masses in all mediastinal compartments. Additionally, RATS shows low conversion rate, high complete resection rate and excellent outcome for masses resected in all compartments of the mediastinum. Our results indicate that RATS has the potential to become the preferred technique for mediastinal tumor resection.