Pectus Carinatum
Protrusion deformities of the anterior chest wall are 10 times
less frequent than depression deformities. Associated disorders,
including congenital heart disease, Marfan’s syndrome, spine
abnormalities, and musculoskeletal defects are as frequent as in
patients with pectus excavatum. The deformity typically is mild or
absent in early childhood and becomes increasingly prominent during the
rapid growth in early adolescence.
Pectus carinatum is believed to stem from an overgrowth of rib
cartilages, with forward buckling and deforming pressure on the body of
the sternum. Carinatum deformities are more variable than excavatum
defects, with two principle forms. In one form the protuberance is
maximal in the upper portion of the sternum and the middle of the
sternum is directed posteriorly. The second and more common form shows
the greatest prominence in the lower portion or body of the sternum.
Minor forms may exist in which rib cartilages may buckle outward without
sternal deformity. Persistent discomfort may warrant removal of the
protruding cartilages.
In most cases, pectus carinatum produces no symptoms beyond
local tenderness or pain in the protruding portion of the chest. No
heart or lung abnormalities result from this deformity, in contrast to
pectus excavatum. In some cases, its association with spine
abnormalities results in altered lung function. A quarter of patients
will have other family members with chest deformities and
musculoskeletal defects are seen in 20%.
Treatment
Variation in surgical treatment is a result of the diversity of
pectus carinatum deformities. The same exposure is used as for the
excavatum defects, with removal of the affected rib cartilages. The
sternum is also cut to make a hinge that will allow it to be secured in
a more downward position. Modifications are used for more asymmetrical
abnormalities. Complications are similar to those for excavatum
surgery.
Article and graphics adapted from O'Neill: Principles of
Pediatric Surgery. © 2003, Elsevier.
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