Pectus Excavatum: Surgical Treatment
THE unsightly deformity of pectus excavatum, or “hollow chest,” is an acquired lesion. It usually occurs in healthy infants who manifest no nutritional problems, contrary to the old concept that it followed childhood rickets. It may be recognized as early as the second month of life; more commonly the alert parent or pediatrician will detect the depression of the sternum in the infant of four to six months of age.
Pectus excavatum is a structural deformity that progresses in severity with body growth. It is caused by abnormal anatomic relationships between the central attachments of the diaphragm and the sternum.1 In the anterior mid-line the diaphragm inserts on the xiphoid cartilage below or at its junction with the body of the sternum. When body growth progresses normally, the diaphragmatic attachment to the xiphoid is lengthened with the increasing anteroposterior diameter of the expanding thorax. If, for some reason, this attaching structure cannot lengthen adequately it will compromise the anterior growth of the xiphoid and the lower sternum. This may be visualized by considering the central attachment of the diaphragm as an unyielding, ligamentous guy rope between the soft, cartilaginous xiphoid and the vertebral column. When the thorax is contracted in expiration, the guy rope is slack and the deformity minimal or nonexistent; during full inspiration the diameter of the bony thorax increases and the guy rope becomes taut, restricting the anterior excursion of the xiphoid. In the infant this deformity, apparent only during inspiration, is first observed when he cries.