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Exercise improvement after pectus excavatum repair is not related to chest wall function.

OBJECTIVES
In patients undergoing corrective surgery for pectus excavatum, there is evidence of improvement in cardiopulmonary function. It is unclear how much of this improvement is attributable to improved chest wall function. Thus, we observed changes in chest wall function in response to an incremental load exercise pre- and postoperatively.


METHODS
Using optoelectronic plethysmography, total and regional chest wall volumes were measured in 7 male patients with severe pectus excavatum who underwent a Nuss correction. Rib cage and abdominal volumes were recorded at rest and during exercise (incremental cycle ergometry), pre- and postoperatively in conjunction with spirometry.


RESULTS
Tidal volume increases during exercise are blunted compared with baseline measurements at 6 days (-36 ± 7%) partially recovering at 6 months postoperatively (-18 ± 22%). This is mirrored by changes in spirometry. Tidal volume decreased during exercise initially in all compartments, but persisted in the rib cage compartment. An increase of 44% (P = 0.009) in exercise tolerance was found 6 months after surgical correction.


CONCLUSIONS
Six months after Nuss correction in pectus patients, there was a decrease in rib cage mobility. Despite reduction, patients had a significant improvement in exercise tolerance. Therefore, we conclude that early postoperative improvement in exercise capacity is not due to changes in chest wall function. The longer term effects on chest wall function are yet to be defined.