Op-icva210212 1..6

OBJECTIVES: To study the influence of sternal transection and costal chondrotomies on the stiffness and stresses in the rib cage of adult patients undergoing Nuss pectus excavatum procedure. METHODS: Four pectus excavatum models with different Haller indexes were created by parameterizing a 3D model of a rib cage obtained based on a computed tomography scan of a patient with no pectus deformity. Using the finite element method, insertion of intrathoracic bars into all models was simulated in 3 conditions, namely, non-intervened, transverse sternal section and costal chondrotomies. Stiffness, stress distribution and maximum stresses for each case were obtained and compared. RESULTS: Transverse sternotomy provided a reduction of 44% to 54% in the stiffness of the rib cage, depending on the Haller index analysed, while chondrotomies promoted a stiffness reduction of 70%. Stress distribution in the rib cage followed similar pattern for all the tested Haller index, but the maximum stress decreased by 36% when performing a transverse sternotomy, whereas when performing costal chondrotomies, it decreased by 47%. TH O R A C IC VC The Author(s) 2021. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved. Interactive CardioVascular and Thoracic Surgery (2021) 1–6 ORIGINAL ARTICLE doi:10.1093/icvts/ivab210 D ow naded rom http/academ ic.p.com /icvts/advance-art.1093/icvts/ivab210/6333767 by gest on 23 Sptem er 2021 CONCLUSIONS: Computational results report that transverse sternotomy reduces appreciably the stiffness of the rib cage, while costal chondrotomies promote even a higher stiffness reduction. Thus, these surgical procedures could improve the clinical outcomes of adult patients undergoing a pectus excavatum repair.