Objectives: Since the introduction of video-assisted lobectomy for non-small-cell lung cancer (NSCLC) into clinical practice, it has been discussed controversially whether mediastinal lymphadenectomy can be performed as effectively as an open procedure via thoracotomy. Therefore, we address this issue in a prospective randomized trial conducted in our institution.
Methods: In total, 66 patients with completely staged clinical Stage I NSCLC were included and randomized either into a video-assisted group (n = 34) or into the conventional lobectomy group (n = 32). The video-assisted thoracoscopic (VATS) lobectomy was performed by using a 4- to 5-cm utility incision in the fourth or fifth intercostal space and two additional 10-mm ports without rib spreading. The conventional lobectomy was done via an anterolateral thoracotomy. Lymph nodes were classified according to the International Association for the Study of Lung Cancer classification; for right-sided tumours, lymph nodes number 2R, 4R, 7, 8, 9, 10, 11 and 12 were dissected, and for left-sided tumours, lymph nodes number 5, 6, 7, 8, 9, 10, 11 and 12. For the subsequent analyses, lymph nodes were grouped into different zones consisting of Zone 1 (2R and 4R), Zone 2 (7), Zone 3 (8R and 9R), Zone 4 (10R, 11 R and 12R), Zone 5 (4 L), Zone 6 (5 and 6), Zone 7 (8L and 9L) and Zone 8 (10 L, 11 L and 12L).
Results: Both groups were comparable with respect to different clinical pathological parameters (age, tumour size and comorbidity). In the video-assisted group, 2 patients were excluded due to conversion to an open thoracotomy. The number of mediastinal lymph nodes removed was as follows: VATS (right side) 24.0 lymph nodes/patient, open right-sided 25.2 lymph nodes/patient, VATS (left side) 25.1 lymph nodes/patient and open left-sided 21.1 lymph nodes/patient. With respect to the zones mentioned above, we found the following results: VATS vs open (mean number of lymph nodes/patient): Zone 1: 9 vs 8.5; Zone 2: 6.3 vs 5.6; Zone 3: 2.4 vs 3.2; Zone 4: 6.5 vs 6.9; Zone 5: 0 vs 0.5; Zone 6: 3.2 vs 3.7; Zone 7: 4.6 vs 3.2 and Zone 8: 10.5 vs 8.9. There were no statistically significant differences between the procedures, either with respect to the overall number of lymph nodes or with respect to the number of lymph nodes in each zone.
Conclusions: Mediastinal lymph node dissection can be performed as effectively by the video-assisted approach as by the open thoracotomy approach. Furthermore, the video-assisted approach allows a better visualization of different lymph node zones.
Keywords: Lymphadenectomy; Mediastinal staging; Systematic lymph node dissection; VATS lobectomy.