Early Prediction of Postoperative Pulmonary Complications After Esophagectomy Using Lung and Diaphragmatic Ultrasound: A Multicenter Prospective Study

Background: Postoperative pulmonary complications (PPCs) remain the leading cause of morbidity and mortality after esophagectomy. Bedside tools enabling early identification of patients at risk are lacking. This study aimed to assess the ability of lung (LUS) and diaphragmatic ultrasound (DUS) to predict PPCs within seven postoperative days (POD). Methods: Multicenter prospective observational study in France including adult patients undergoing elective thoracic esophagectomy between August 2022 and March 2025. LUS and DUS were performed daily. The primary endpoint was the occurrence of at least one PPC within seven PODs. Predictive performance was assessed using multivariable logistic regression and receiver-operating-characteristic (ROC) analyses. Results: Among 275 patients, 115 (41.8%) developed PPCs. LUS on POD0 was associated with PPCs (OR 1.36, 95%CI 1.25-1.48) with an AUC of 0.74 (0.74 95%CI 0.68-0.80). LUS score on POD1 was higher in patients with PPCs (9.8±4.5 vs 5.2±3.4; p <0.001) and independently predicted PPCs (OR 1.18 [95% CI, 1.08–1.30]; p < 0.001). Higher diaphragmatic excursion in deep breathing was protective against PPCs (OR 0.96 [0.92–0.99]; p = 0.02). Alveolar consolidation on POD1 was the strongest categorical predictor of PPCs (adjusted OR 7.74 [95% CI, 3.24-18.47]; p < 0.001). The area under the ROC curve reached 0.80 [0.75-0.86] for LUS, 0.84 [0.79-0.89] for DUS in deep breath, and 0.89 [0.88-0.90] for the multivariable model. Conclusion: LUS obtained immediately after extubation (POD0) provides early prognostic information for PPCs after esophagectomy, while POD1 LUS and DUS add complementary value and support accurate early risk stratification.