Retrospective study on video-assisted vs. open mediastinal lymphadenectomy for non-small cell lung cancer: a propensity-matched analysis.

Background: This retrospective study is designed to compare the surgical outcomes of mediastinal lymph node (MLN) dissection between the two groups of non-small cell lung cancer (NSCLC) patients underwent lung cancer surgery through video-assisted thoracoscopic surgery (VATS) or thoracotomy, as well as classify the differences and identify the safer method between two groups.

Methods: A total of 497 patients underwent pulmonary lobectomy and systemic MLN dissection were enrolled in this study. They were divided into VATS group (n=242) and traditional thoracotomy (TT) group (n=255). The VATS group received three-port VATS, while the thoracotomy group underwent posterior-lateral or muscle sparing thoracotomy. The range of MLN dissection included groups 2R, 4R, 7, 8, 9 in right-sided lung cancer surgery and groups 4L, 5, 6, 7, 8, 9 in left-sided. The two groups were matched at a ratio of 1:1 using the propensity score matching (PSM) method.

Results: Out of 497 patients, 376 cases were matched for PSM, with 188 cases in each group. Baseline date did not get any significant difference between two groups. The average group number of MLN dissection in VATS group and TT group was 4.14 and 3.97, respectively. While the average amount of dissected lymph nodes in both groups were 16.63 and 17.32, respectively. Compare with the lymph node numbers among all the groups in TT group, only the number of group 7 though left approach (7L) in VATS group was statically significant. Besides, the operation time and postoperative length of hospital stay in VATS group were superior to those in TT group (P<0.05). No significant difference had been found in intraoperative blood loss, accessory surgical injury and postoperative complication between two groups.

Conclusion: Compared with thoracotomy, systemic MLN dissection and pulmonary lobectomy via VATS has quicker recovery, less postoperative complication and length of hospital stay with similar surgical outcomes. Moreover, our findings also suggest thoracotomy has an advantage on the dissection of MLN in group 7L.