Intraoperative Volume Decay Measured Through Mechanical Ventilation as a Predictor of Prolonged Postoperative Air Leak After Uniportal Video-Assisted Thoracic Surgery Lung Resection

Background/Objectives: Prolonged postoperative air leak (PAL) remains one of the most common complications after lung resection, significantly affecting postoperative recovery and healthcare utilization. While several preoperative risk factors have been identified, reliable intraoperative predictors are still lacking. This study aimed to evaluate whether intraoperative ventilator-derived parameters—volume decay (Vol-Decay) and pressure decay (Pres-Decay)—are associated with the development of PAL following uniportal video-assisted thoracic surgery (VATS) lung resection. Methods: We conducted a single-center study including 277 consecutive patients undergoing uniportal VATS lung resection for neoplastic disease between May 2023 and April 2024. At the end of the surgical procedure, intraoperative Vol-Decay and Pres-Decay were measured using the mechanical ventilator under standardized conditions. PAL was defined as an air leak persisting for more than 5 days within 30 days after surgery. Univariate and multivariate analyses were performed to identify independent predictors of PAL, and the optimal Vol-Decay cut-off was determined using Youden’s index. Results: PAL occurred in 18 patients (6.5%). At univariate analysis, higher smoking exposure, lower FEV1, lower FEV1/FVC ratio, and higher Vol-Decay were significantly associated with PAL. At multivariable analysis, only FEV1 (p = 0.013) and Vol-Decay (p = 0.038) remained independent predictors. The optimal Vol-Decay cut-off was 22 mL (AUC 0.64), with high specificity (0.94) but low sensitivity (0.34). Patients with Vol-Decay > 22 mL showed a significantly higher incidence of PAL compared to those with lower values (27.3% vs. 4.7%). Conclusions: Intraoperative Vol-Decay represents a simple, objective, and reproducible parameter associated with the development of prolonged air leak after uniportal VATS lung resection. Its measurement may enable real-time risk stratification and support personalized intraoperative decision-making, potentially guiding targeted corrective strategies. Further prospective multicenter studies are warranted to validate these findings and confirm their clinical applicability.