Double crush to the thorax: Pectus excavatum and kyphoscoliosis

The relationship between adolescent idiopathic scoliosis (AIS) and pectus excavatum (PE) is not well understood. We hypothesize that the combined thoracic malformations of AIS and PE may lead to a "double crush to the thorax" resulting in greater cardiopulmonary impairment than either thoracic malformation in isolation. We evaluated the Haller index (HI) and thoracic volume changes that occur pre- and post-operatively for kyphoscoliosis and PE by examining the case of a 12-year-old girl who had a "double crush to the thorax." Using posterior-to-anterior and lateral standing scoliosis films obtained before and after both operations we determined the PE severity index (HI). Using the same radiographs a Blender based computational model was used to approximate the thoracic volumes. With correction of kyphoscoliosis the HI acutely increased from 1.9 to 3.2 with a decrease in thoracic volume of 11% resulting in shortness of breath and tachycardia. With PE repair the HI was returned to normal (HI = 2.4) and the thoracic volume increased 18%, with resolution of her cardiopulmonary symptoms. When severe kyphoscoliosis and PE co-exist consideration should be given to the implication of the "the double crush to the thorax" if cardiopulmonary symptoms arise.