A New Functional Threshold for Minimally Invasive Lobectomy.

Objective: To assess the performance of a lower predicted postoperative (ppo) forced expiratory volume in 1 second (FEV 1 ) or diffusion capacity of the lung for carbon monoxide (DLCO) (ppoFEV 1 /ppoDLCO) threshold to predict cardiopulmonary complications after minimally invasive surgery (MIS) lobectomy.

Background: Although MIS is associated with better postoperative outcomes than open surgery, MIS uses risk-assessment algorithms developed for open surgery. Moreover, several different definitions of cardiopulmonary complications are used for assessment.

Methods: All patients who underwent MIS lobectomy for clinical stage I to II lung cancer from 2018 to 2022 at our institution were considered. The performance of a ppoFEV 1 /ppoDLCO threshold of <45% was compared against that of the current guideline threshold of <60%. Three different definitions of cardiopulmonary complications were compared: Society of Thoracic Surgeons (STS), European Society of Thoracic Surgeons (ESTS), and Berry and colleagues' study.

Results: In 946 patients, the ppoFEV 1 /ppoDLCO threshold of <45% was associated with a higher proportion correctly classified [79% (95% CI, 76%-81%) vs 65% (95% CI, 62%-68%); P <0.001]. The complication with the biggest difference in incidence between ppoFEV 1 /ppoDLCO of 45% to 60% and >60% was prolonged air leak [33 (13%) vs 34 (6%); P <0.001]. The predicted probability curves for cardiopulmonary complications were higher for the STS definition than for the ESTS or Berry definitions across ppoFEV 1 and ppoDLCO values.

Conclusions: The ppoFEV 1 /ppoDLCO threshold of <45% more accurately classified patients for cardiopulmonary complications after MIS lobectomy, emphasizing the need for updated risk-assessment guidelines for MIS lobectomy to optimize additional cardiopulmonary function evaluation.