Dynamic effects of the Nuss procedure on the spine in asymmetric pectus excavatum.
OBJECTIVE
This study aimed to elucidate dynamic effects of the Nuss procedure on the spine in the treatment of patients with pectus excavatum with asymmetric thoraces.


METHODS
Twenty-five patients with pectus excavatum who underwent the Nuss procedure were categorized into 4 groups by preoperative morphology of the spine and thoracic asymmetry. In group 1 (n = 8), the right side of the thorax was concave and the spine bowed to the right. In group 2 (n = 4), the right side of the thorax was concave and the spine bowed to the left. In group 3 (n = 5), the left side of the thorax was concave and the spine bowed to the right. In group 4 (n = 8), the left side of the thorax was concave and the spine bowed to the left. With computed tomographic data, finite-element models were produced to simulate each patient's thorax. Thereafter, dynamic response patterns of the spine to the Nuss procedure were examined. Validity of these biomechanical findings was verified by referring to clinical outcomes.


RESULTS
In group 1 and group 4 models, deformed spines were straightened; in group 2 and group 3 models, spinal bowing increased. These biomechanical findings were compatible with clinical evaluations.


CONCLUSIONS
Performance of the Nuss procedure for asymmetric pectus excavatum exerts dynamic influence on the spine. Response patterns of the spine are predictable from morphologic relationships between the asymmetric patterns of the anterior thoracic wall and the spine.
Nagasao
Tomohisa
T
Department of Plastic and Reconstructive Surgery, School of Medicine, Keio University, Tokyo, Japan. nagasao@sc.itc.keio.ac.jp
Noguchi
Masahiko
M
Miyamoto
Junpei
J
Jiang
Hua
H
Ding
Weijin
W
Shimizu
Yusuke
Y
Kishi
Kazuo
K
D001696:Biomechanical Phenomena; D002648:Child; D005260:Female; D005660:Funnel Chest / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D012129:Respiratory Function Tests; D013904:Thoracic Vertebrae / Q000002:abnormalities* / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome