Comparison of Biomechanical Characteristics of Chest Wall according to Displacement Control Method of Metal Bar during Virtual Nuss Procedure

Beop-Yong Lim 1, Chi-Seung Lee 2, Youngwoong Kim 3, Hyo Yeong Ahn 4 and Hoseok I 4

1. Department of Biomedical Engineering, Graduate School, Pusan National University, Busan, Republic of Korea 2. Department of Convergence Medicine, School of medicine, Pusan National University, Busan, Republic of Korea 3. Department of Thoracic and Cardiovascular Surgery, Trauma Center, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Republic of Korea 4. Department of Thoracic and Cardiovascular Surgery, School of medicine, Pusan National University, Busan, Republic of Korea

Purpose : Existing biomechanical studies of the Nuss procedure take the simply anterior translating metal bar under the posterior surface of sternum. However, the sternum is anterior translated while the metal bar is concavely inserted and rotated in actual surgery. This study aims to improve the accuracy of finite element analysis for pectus excavatum by establishing the difference between the anterior translation method and the rotation method.

Methods : In the three-dimension model of chest wall, the convex metal bar was displaced in the anterior direction of sternum. Another concave metal bar was given a rotational displacement to make the convex state. As a result of analysis, the maximum equivalent stress and strain, the anterior translation amount of sternum, and the Haller index were compared.

Results : The maximum equivalent stress and strain were about 41.6 times higher in the anterior translation method than in the rotation method. The anterior translation amount of sternum was 99.45% in the anterior translation method and 0.87% in the rotation method, which was different from the postoperative data. The Haller index was shown a difference of 16.84% in the anterior translation method and 0.67% in the rotation method.

Conclusion : When comparing the anterior translation method and the rotation method, the rotation method was similar to the actual surgical result and the two methods should be distinguished because of different effects on the Nuss procedure. Therefore, when conducting a study on the finite element analysis of pectus excavatum, this study is suggested the rotation method of the metal bar.

책임저자: Hoseok I

Department of Thoracic and Cardiovascular Surgery, School of medicine, Pusan National University, Busan, Republic of Korea

발표자: Hoseok I, E-mail : ihoseok@pusan.ac.kr