The effectiveness of double-bar correction for pectus excavatum: A comparison between the parallel bar and cross-bar techniques

Purpose: To compare the effectiveness between parallel bar and cross-bar techniques for treating pectus excavatum. Methods: A total of 80 patients who underwent parallel bar insertion (group 1) or cross-bar insertion (group 2) were evaluated retrospectively. From the pre- and post-operative chest CT images, vertebral-level-specific pectus indices were defined as the ratio of the maximum transverse diameter to the anteroposterior diameter of the thoracic cavity at a specific vertebral level and measured at 3 levels up (3Up-PI, 2Up-PI, 1Up-PI) and 1 vertebral level down (1Down-PI) from the narrowest point. The effectiveness of double-bar correction was compared between the 2 groups using postoperative vertebral level-specific pectus index changes. Results: A total of 44 patients were enrolled in group 1, and 36 patients were enrolled in group 2. Preoperative pectus index values were not different between the 2 groups (4.5 ± 1.0 vs. 4.9 ± 1.5, P = 0.135). After double-bar correction, pectus index significantly decreased in both groups. There were no differences in postoperative pectus indices between the 2 groups (2.7 ± 0.4 vs. 2.6 ± 0.3, P = 0.197). Postoperative changes in 3Up-PI, 2Up-PI, and 1Up-PI were not significantly different between the 2 groups (P > 0.05). However, postoperative changes at the narrowest level and at 1Down-PI were significantly greater in group 2 than in group 1 (1.78 ± 0.85 vs. 2.32 ± 1.44, P = 0.009; 1.21 ± 0.70 vs. 1.70 ± 1.20, P = 0.009, respectively). Conclusions: Double-bar correction appears to be effective for treating pectus excavatum. The cross-bar insertion technique might be superior to the parallel bar insertion technique for correcting a wider range of deformities, especially at the lower part of the depression.