ABSTRACT
Pectus excavatum is the most common chest wall deformity in infants, children, and adolescents. Its incidence is estimated at between 1 and 400 live births and 7.9 per 1000 births and has a male to female ratio of 3:1. The exact etiology of pectus excavatum is unknown. It has a genetic predisposition with patients having a family history of chest wall deformities in 37 percent of cases. Patients may have a family history of a carinate or protrusion deformity. The pectus excavatum depression is created by two components. First, is a posterior angulation of the sternum generally at the level of the insertion of the second or third costal cartilages. The second component is posterior angulation of the costal cartilages to meet the sternum. In older teenagers, the posterior angulation may involve the most medial portion of the osseous rib, as well as the cartilaginous component. The pectus excavatum depression may be symmetric or asymmetric. In the asymmetric deformities, the more acute and severe depression is primarily on the right side. The rarest configuration of pectus excavatum is a combination of ipsilateral depression and a contralateral carinate protrusion. In approximately 90 percent of cases, the excavatum deformity is noted within the first year of life. This is in marked contrast with a carinate deformity where almost half the patients have the protrusion noted after they enter the pubertal growth spurt.
