Impact of Nuss procedure on thoracic cavity and analysis of related factors

Objective To evaluate the impact of Nuss procedure by comparing the dimensional changes of thoracic cavity of pectus excavatum (PE) patients on computed tomography (CT) images. Methods A total of 50 PE cases undergoing Nuss procedure from January 2014 to December 2018 were selected. Retrospective reviews were performed for clinical data and CT examinations of chest. The anteroposterior and transverse diameters were measured at multiple thoracic vertebral levels. Paired-sample t-test was employed for comparing the differences between preoperative and postoperative parameters. And independent sample t-test was performed for comparing the inter-group differences in patient age, gender, insertion time of bar and type of PE. Results The postoperative anteroposterior diameters from T8 to T12 were significantly higher than their preoperative values while T3 to T5 anteroposterior diameters and T8 to T10 transverse diameters were lower than their preoperative values. In children aged under 10 years, the duration of bar placement time ≥2 years and girl gender, the anteroposterior diameter changes were larger than the other groups at multiple vertebral levels (P<0.05) and the differences were statistically significant. Conclusions Anterior chest wall depression significantly improves after Nuss procedure. Early correction and longer correction time offer better corrective outcomes. The transverse diameter of thoracic cavity is somewhat limited in growth. Key words: Thoracic vertebrae; Nuss procedure; Thoracic change; CT measurement; Pectus excavatum