Pectus Deformities: Pectus Excavatum and Pectus Carinatum

Georgia Koltsida, MD, and Oscar Henry Mayer, MD

Introduction/Etiology/Epidemiology

•Pectus deformities are the most common congenital skeletal deformities.

•The incidence rate of pectus excavatum is approximately 1 in 400 live births, whereas pectus carinatum is less frequent.

•Male patients are affected 5 times more often than female patients, while patients of African American and Hispanic descent rarely have pectus deformities.

•The exact pathogenesis of pectus deformities is unknown. No clear genetic link has been found, but there are collagen defects that can lead to abnormal costochondral growth.

•Pectus deformities may occur in isolation or in association with syndromes such as Marfan, Noonan, and Turner syndromes.

•Mechanical factors have also been proposed.

Pathophysiology

•The sternum consists of 3 parts:

—The manubrium, the widest portion, which is attached to the clavicles and the first 2 pairs of ribs

—The body, the longest segment, which is connected to the remaining ribs

—The xiphoid process, which is small and triangular

•The sternum protects the heart, trachea, and thymus and provides attachment for the costal cartilage.

•The joints between the sternum and the costal cartilage of the ribs flex to allow the ribs to rotate upward and anteriorly during inspiration and increase the cross-sectional area of the thorax.

•Pectus excavatum and pectus carinatum can decrease the thoracic volume and impair the growth or expansion of the lungs. However, in a few patients with pectus deformities, obstructive and restrictive lung disease occurs.

Clinical Features

•Pectus excavatum (“funnel chest”) is the posterior depression of the sternum and adjacent costal cartilage. It is characterized by the substantial depth and length of the depression, the symmetry between the right and left hemithorax, and the presence of associated sternal rotation.

•Pectus carinatum (“pigeon chest”) is the protrusion of the sternum and adjacent ribs. Two general variants exist.

—The chondrogladiolar variant consists of anterior protrusion of the body of the sternum, with symmetrical protrusion of the lower costal cartilages.

—In the costomanubrial variant, the manubrium protrudes and can be either symmetrical or asymmetrical.

Diagnostic Considerations

History

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