Background: Differences in post-Nuss procedure pulmonary function based on the pectus excavatum subtype have not been investigated in adolescents. We evaluated differences in pulmonary function before and after the Nuss procedure according to preoperative morphology.
Methods: We performed a retrospective review of eighteen male patients who had undergone the Nuss procedures. There were nine patients each with symmetric and asymmetric morphology. Patients were younger than 18 years and had no history of respiratory diseases. Pulmonary function was assessed 2 weeks before and 4-6 months after the surgery. Preoperative and postoperative pulmonary function data were compared between the symmetric and asymmetric types. The paired t-test was used to compare the differences within each group and an analysis of covariance (ANCOVA) was used to access intergroup differences.
Results: There were no significant demographic differences between patients with symmetric and asymmetric subtypes. Patients with the asymmetric type had a lower preoperative total lung capacity (TLC) (p = 0.018), vital capacity (VC) (p = 0.0308), and inspiratory capacity (IC) (p = 0.0373). In both types, the forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and VC were all significantly decreased postoperatively compared to baseline (all, p < 0.01). The asymmetric type showed further reductions in peak expiratory flow (PEF) (p = 0.0391) and IC (p = 0.0084) postoperatively. The residual volume (RV) (p = 0.0092) and RV/TLC ratio (p = 0.0025) increased significantly in the asymmetric type, but only the postoperative PEF values differed significantly between the two types (p = 0.0151).
Conclusions: The asymmetric type had poorer preoperative lung volumes and poorer postoperative pulmonary function, with significantly lower PEF compared to the symmetric type cases. Preoperative and postoperative lung function needs more careful evaluation until pectus bar removal in the asymmetric type of pectus excavatum.