Effects on lung function of multiple expansion thoracoplasty in children with thoracic insufficiency syndrome: A longitudinal study

Study Design. Longitudinal study of intraoperative pulmonary function in young children with thoracic hypoplasia and scoliosis undergoing multiple expansion thoracoplasty using the vertical expandable prosthetic titanium ribs (VEPTRs). Objective. To test the long-term efficacy of VEPTR multiple expansion thoracoplasty. Summary of Background Data. To our knowledge, no direct measurements of pulmonary function have been reported with VEPTR expansion thoracoplasty. Methods. There were 10 children with thoracic insufficiency syndrome, secondary to thoracic hypoplasia with progressive scoliosis, studied. A mobile pulmonary function laboratory unit was used to study forced vital capacity (FVC), maximum expiratory flow volume curves, and respiratory system compliance (C-rs) with the patient under general anesthesia immediately before and after expansion thoracoplasty. Studies were repeated every 6 months at each subsequent operation for expansion thoracoplasty for the duration up to 33 months. Results. At the baseline studies, FVC showed a moderate-to-severe decrease (69% of predicted values), indicating the presence of significant restrictive lung defect. Only 1 of 10 children had severe airway obstruction. The baseline C-rs was markedly decreased in part because of the presence of significant atelectasis. C-rs increased with an average of 42% after repeated hyperinflation ( deep sighs). There was no change in lung volume or function immediately before versus after completion of expansion thoracoplasty. FVC increased significantly over time, with an average rate of 26.8% per year, the rate of increase similar to that of healthy children of comparative ages. In terms of percent-predicted values, FVC did not change significantly between the baseline and last test, indicating that in most children studied, lung growth kept up with body growth. Conclusion. Although it is difficult to assess the extent of the efficacy without a proper or historical control group for comparison, the present study indicates that in children with severe thoracic insufficiency syndrome, the insertion of VEPTRs with multiple expansion thoracoplasties is beneficial over time, by allowing the lungs to expand with body growth without further deterioration in lung function.