Does expansion thoracoplasty improve the volume of the convex lung in a windswept thorax?

BACKGROUND

Expansion thoracoplasty using the Vertical Expandable Prosthetic Titanium Rib increases the measured height and volume of the concave hemi thorax, but the effect on the convex, non-instrumented lung is unknown. The purpose of this study was to measure changes in lung volume and density in the convex lung after expansion thoracoplasty.

METHODS

The volume and density of the lungs was measured in 12 children with congenital scoliosis and fused ribs before and after concave expansion thoracoplasty using serial computed tomography scans.

RESULTS

There were 8 boys and 4 girls with an average age of 6.4 years at initial implant. The average length of follow-up was 17.5 months. All patients showed increased total lung volumes by an average of 250 cc (range 24 to 795 cc). The volume of the concave lung increased by an average of 55% and the lung density decreased by an average of 6%. The volume of the convex lung increased by an average of 60%, and the density decreased by an average of 7%. Nine of 12 patients showed improvement in density of the convex lung.

DISCUSSION

These findings suggest that concave expansion thoracoplasty increases overall lung volume in children with congenital scoliosis and fused ribs as measured by computed tomography scan. In addition, expansion thoracoplasty seems to have a beneficial effect on the convex, non-operated hemi thorax. Decreases in measured lung density suggest improved aeration of the lung, which may prove to be beneficial to overall pulmonary function.

LEVEL OF EVIDENCE

Level 4 therapeutic studies: case series.