Early changes in pulmonary function after vertical expandable prosthetic titanium rib insertion in children with thoracic insufficiency syndrome.

BACKGROUND: The vertical expandable prosthetic titanium rib (VEPTR) has been inserted in children with thoracic insufficiency syndrome for the last decade to expand and support the chest and allow for further lung growth. There are minimal published data evaluating the postoperative change in lung function after VEPTR insertion. We hypothesize that there will be a significant increase in lung function after VEPTR insertion, and the earlier the insertion, the greater the improvement.
METHODS: The Chest Wall Disorders Study Group Database, containing data before and after VEPTR insertion from 7 different centers, was queried for spirometry and lung volume measurements, and the data were analyzed to assess the short-term effect on lung function of VEPTR placement.
RESULTS: There was a statistically significant decrease in forced vital capacity, forced expiratory volume in 1 second as a percent of predicted, an increase in residual volume (RV) that did not reach statistical significance, and there was no change in total lung capacity at the first postoperative visit (7.7 +/- 4.8 months). There was a significant decrease in Cobb angle. There was no correlation between absolute change in any pulmonary function and Cobb angle age at the time of surgery.
CONCLUSIONS: Although there is a clinically and radiographically apparent expansion of the thorax after VEPTR insertion, there is no similar improvement in lung volume, and instead there is a decrease in forced vital capacity and increase in residual volume, the explanation for which requires further study. This lack of change in pulmonary function after VEPTR insertion suggests that the benefit of VEPTR insertion may lie more in stabilizing the thorax and improving respiratory mechanics measured in other ways.