A large single-center propensity score-matched cohort study on outcomes and complications based on the number of corrective bars used in the Nuss procedure.

The Nuss procedure is the most common corrective surgery for pectus excavatum. We analyzed treatment outcomes and complication rates in 1238 patients treated with the Nuss procedure from 2002 to 2021, focusing on the number of corrective bars used. Using Propensity Score Matching based on age, sex, BMI, pre-operative FEV1, and the Haller index, we created two groups: 546 patients with a single bar and 546 with two bars. Both groups achieved similar correction effects (Haller index: single bar = 2.58 vs. two bars = 2.56; p = 0.65). In the univariate analysis, in the two-bar group, the postoperative complications were observed more often (28.6% vs. 15.4%, p < 0.001), including pneumothorax (11.2% vs. 6.2%, p < 0.001), hemothorax (3.7% vs. 0.7%, p < 0.001), additional drainage (13.7% vs. 5.3%, p < 0.001), the need for thoracentesis (8.6% vs. 2.9%, p < 0.001), bar displacement (3.8% vs. 0.7%, p < 0.001), pleural effusion (10.6% vs. 3.1%, p < 0.001), and fever (6.6% vs. 3.8%, p < 0.041). In the logistic regression, two bars significantly increased the risk of postoperative complications (p = 0.019), including hematoma (p = 0.036), pleural effusion (p = 0.002), and the need for thoracentesis (p = 0.013). Using two corrective bars during the Nuss procedure is associated with a higher rate of postoperative complications but similar corrective results.