Abstract

 

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%.

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.

中文翻译：

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降低胸腔刚度以进行微创漏斗胸修复：生物力学评估

摘要

 

目标

研究胸骨横断和肋软骨切开术对接受漏斗胸手术的成年患者胸腔刚度和应力的影响。

方法

通过参数化一个胸腔的 3D 模型，创建了四个具有不同 Haller 指数的漏斗胸模型，该模型是基于一个没有胸廓畸形的患者的计算机断层扫描获得的。使用有限元方法，在未介入、胸骨横切和肋软骨切开三种情况下模拟了将胸内钢筋插入所有模型的情况。获得并比较了每种情况下的刚度、应力分布和最大应力。

结果

根据所分析的 Haller 指数，横向胸骨切开术使胸腔的刚度降低了 44% 至 54%，而软骨切开术则使刚度降低了 70%。在所有测试的 Haller 指数中，肋骨中的应力分布都遵循类似的模式，但在进行横向胸骨切开术时最大应力下降了 36%，而在进行肋软骨切开术时，最大应力下降了 47%。

结论

计算结果表明，横向胸骨切开术显着降低了胸腔的刚度，而肋骨软骨切开术促进了更高的刚度降低。因此，这些外科手术可以改善接受漏斗胸修复的成年患者的临床结果。