Zone-specific intrathoracic volume remodeling following single-bar, cross-bar, and XI-bar repair of pectus excavatum

The primary objective of pectus excavatum (PE) repair is to correct chest wall deformity, relieve cardiac compression, and expand thoracic volume. However, quantitative comparisons of volumetric remodeling among different bar configurations are scarce. We retrospectively analyzed 151 patients who underwent PE repair using single-bar (S, n = 42), cross-bar (C, n = 49), or XI-bar (X, n = 60) techniques between April 2019 and February 2021. Pre- and postoperative thoracic volumes in three anatomical zones were measured using SYNAPSE 3D imaging software (Fujifilm, Tokyo, Japan). Propensity score matching (PSM) based on age and body mass index was applied to minimize baseline differences. In the unmatched cohort, Group X demonstrated the greatest anterior thoracic volume expansion in Zones 1 and 2 (p < 0.01). After PSM, Group X (n = 16) maintained significantly larger volume gains in Zone 1 (294 ± 238 mL vs. 200 ± 152 mL) and Zone 2 (147 ± 168 mL vs. −36 ± 92 mL) compared with Group C (n = 16) (both p < 0.01). Hospital stay was shorter in Group X (4.4 ± 0.7 vs. 5.5 ± 1.4 days, p = 0.012), while ΔHaller index and complication rates were comparable among groups. The XI-bar technique achieves superior anterior thoracic remodeling and shorter hospitalization compared with the cross-bar, without compromising safety or correction outcomes. It also produces greater volumetric gains than the single-bar technique. These results demonstrate that bar configuration directly influences zone-specific thoracic remodeling and support the XI-bar as the optimal approach for achieving comprehensive and balanced correction in PE repair.