Video-Assisted Thoracoscopic Surgery versus open approach for systematic mediastinal lymph node dissection as surgical staging in major pulmonary resections for lung cancer

Introduction Oncological pulmonary resection should include ipsilateral hilar and mediastinal systematic lymphatic dissection allowing adequate pathological staging. Video-Assisted Thoracoscopic Surgery (VATS) has been proposed as an appropriate surgical procedure for treatment of early-stage lung cancer patients. This study aims to compare VATS versus Thoracotomy lymph node dissection in patients who underwent pulmonary resection for lung cancer. Methods This is a retrospective analysis of prospectively collected data from 585 patients operated at La Princesa University Hospital in Madrid (Spain) from December 2007 to January 2018. All included patients underwent complete major pulmonary resection, lobectomy or bilobectomy, and mediastinal lymph node dissection. Patients were divided in two groups, VATS group with 290 patients and thoracotomy group (TT) with 295 patients. Results The number of lymph nodes resected in each group did not present significant differences. VATS-group was 13.4 and TT-group was 14.1. We did not appreciate any significant difference regarding the identification of positive hilar lymphadenopathies in VATS-group versus TT-group, 36 and 41 patients respectively. However, we observed differences in patients with mediastinal lymph node metastasis (N2 disease). 34 cases (11.7%) in VATS-group and 28 cases (9.5%) in the TT-group. Lymphadenectomy 2R and 4R stations was equivalent in both groups and did not show any statistically significant difference. In the same way, there was no difference in the number of lymph nodes for levels 7R and 8R. Hilar lymphadenectomy (10R and 11R) was performed in both procedures in an equivalent manner obtaining 3.4 lymphadenopathies in VATS-group and 3.3 lymphadenopathies in TT-group. Regarding lymphadenectomy on the left side, we did not observe any difference between both groups at 5L or 6L levels. Otherwise, subcarinal lymphadenectomy on the left side showed differences when this was performed by VATS in comparison to open surgery. 3.2 lymph nodes in the VATS-group versus 4.9 lymph nodes in TT-group. This difference was statistically significant (p < 0.01). There was no difference in at the level of 8L and 9L stations. Hilar lymphadenectomy at 10L and 11L levels was superior in VATS-group, 4.4 lymphadenopathies, respect to TT-group, 3.1 lymph nodes. This difference was statistically significant (p <0. 01). Conclusions VATS seems to be at least equivalent to thoracotomy for pulmonary major resections in terms of oncological and staging criteria.