[Anatomical resection for non-small cell lung cancer: cardiopulmonary exercise testing in assessing the risk of respiratory complications].

Objective: To assess the role of cardiopulmonary exercise testing in examination of patients with high risk of respiratory complications in anatomical resections for non-small cell lung cancer.

Material And Methods: A non-randomized retrospective single-center study was devoted to immediate results of surgical treatment of patients with NSCLC between December 2020 and April 2021. Median age of patients was 65 (84; 30) years, male-to-female ratio - 129 (57%)/98 (43%). All patients were examined according to a unified algorithm recommended by the American (ATS) and European (ESTS) societies of thoracic surgeons. At the first stage, we analyzed airflow rate and performed non-invasive exercise tests (6-minute walk and/or stair test). Resections of lungs were performed in 231 patients, anatomic lung resections - in 227 patients (lobectomy - 199, bilobectomy - 4, segmentectomy - 17, pneumonectomy - 7). We excluded 4 patients who underwent non-anatomic lung resections (marginal resections).

Results: Among 236 patients referred for anatomical lung resections, 34 (14.4%) ones were selected for cardiopulmonary testing. Selection was based on low exercise tolerance and/or severe decrease in predictive respiratory parameters (FEV<50%). Patients were divided into 4 groups depending on peak oxygen consumption. There were 5 (2%), 10 (29.4%), 11 (32.3%) and 8 (23.5%) patients with extremely high, high, moderate and low risk of respiratory complications, respectively. Surgeries were performed for IA1 (=6), IA2 (=50), IA3 (=37), IB (=31), IIA (=19), IIB (=37), IIIA (=25) and IIIB (=4) stages. The overall incidence of postoperative complications was 23% (95% CI: 18-28.8). Complications Clavien-Dindo grade I, IIIA, IIIB, IVA, IVB and V prevailed in both groups. Median postoperative hospital-stay (6 (6; 8) vs. 7 (6; 8) days) and time of pleural drainage (4 (2; 5) vs. 3 (3; 4) days) were similar. Organ-sparing procedures prevailed in the main group (5 (26%) out of 19 (95% CI: 11.81-48.8) vs. 12 (6.7%) out of 180 (95% CI: 3.8-11.3)). Overall mortality (=231) was 1.7% (95% CI: 0.7-4.4). Mortality throughout the first postoperative year was 24% (95% CI: 12.2-42.1) and 7.4% (95% CI: 4.2-11.3), respectively.

Conclusion: Cardiopulmonary exercise testing makes it possible to objectively assess exercise tolerance and identify high-risk patients for respiratory complications. These data are valuable when planning the treatment of patients with non-small cell lung cancer.