Dynamic effects of the Nuss procedure on the spine in asymmetric pectus excavatum
Received 13 March 2010; received in revised form 17 May 2010; accepted 20 June 2010. published online 22 July 2010. Corrected Proof
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.
aDepartment of Plastic and Reconstructive Surgery, School of Medicine, Keio University, Tokyo, Japan
bDepartment of Plastic Surgery, Nagano Children’s Hospital, Azumino, Japan
cDepartment of Plastic Surgery, Shanghai Second Military Medical College, ChangZheng Hospital, Shanghai, China
Address for reprints: Tomohisa Nagasao, MD, PhD, Department of Plastic and Reconstructive Surgery, Keio University Hospital, Shinjuku-Ward Shinanomachi 35, Tokyo Japan.
Supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan (C-21500453).
ABSTRACT