Pectus carinatum is a medical deformity which is characterized by the protrusion of the sternum and ribs, and as a result, is often referred to as Pigeon chest. It is the polar opposite of Pectus Excavatum, where the sternum caves inwards, not outwards.
What are the causes of Pectus Carintum?
Pectus Carinatum is caused by an overgrowth of the costal cartilage which causes the sternum to protrude forward. It can occur in three distinct ways. The least common variation occurs post surgically after open heart surgery. Sometimes the sternum does not heal flat and there is a protrusion of the sternum due to trauma inflicted during surgery. The second most common is a congenital defect (birth defect). It is sometimes visible in newborns as a rounded chest and as they reach 2 to 3 years of age and the sternum begins to grow outwardly more severely. However, the most common occurrence for Pectus Carinatum seems to appear in children aged 11-14 years old when many adolescents undergo a more rapid growth spurt.
Pectus Carinatum may occur as a solitary congenital abnormality or in association with other genetic disorders or syndromes such as Marfan syndrome, Scoliosis, Ehlers Danlos Syndrome, Morquio syndrome, Noonan syndrome, Trisomy 18, Trisomy 21, homocystinuria, osteogenesis imperfecta, multiple lentigines syndrome, and Sly syndrome. Additionally, In about 1/4 of cases the patient has a direct family member with Pectus Carinatum.
Pectus deformities are extremely common; about 1 in 400 people have a pectus disorder. However, Pectus Carinatum is much rarer than Pectus Excavatum, occurring in only about 1/5 of people with a pectus abnormality. Furthermore, the disorder is very much male centric, with roughly four out of five patients being male.
What are the Symptoms?
Typically, individuals with Pectus Carinatum develop healthy hearts and lungs, however, the deformity may prevent these from functioning optimally. In moderate to severe cases of Pectus Carinatum, the chest wall is rigidly held in an outward position and as a result, respiration is inefficient, requiring the use of the diaphragm and accessory muscles rather than normal chest muscles. This negatively affects gas exchange and causes a decrease in stamina. Consequently, children with abnormality often tire quicker than their peers, due to shortness of breath and fatigue.
Pectus Carinatum can also be a cause of Scoliosis (curvature of the spine) and some individuals with the condition have mitral valve prolapse, a condition in which the heart mitral valve functions abnormally. Connective tissue disorders involving structural abnormalities of the major blood vessels and heart valves are also seen as a symptom of Pectus Carinatum.
Apart from the possible physiological symptoms in severe cases, Pectus Carinatum, just as with Pectus Excavatum, can have a significant negative psychological impact. Some individuals find that the shape of their chest damages their self-image and confidence, possibly disrupting social connections and causing them to feel uncomfortable throughout adolescence and adulthood.
How is it treated?
Pectus Carinatum typically becomes more severe during adolescent growth and may worsen throughout adult life. The secondary effects, such as scoliosis and cardiovascular and pulmonary conditions, may worsen with age also. For those with a more severe case of the condition, the physological symptoms must be addressed since the possibility of lifelong cardiopulmonary difficulties is serious enough to warrant a thoracic surgeon. Most children with the disorder are advised to avoid surgery in favor of less evasive treatment options such as the external bracing technique.
External bracing technique
This treatment method involves the use of a customized chest-wall brace that applies direct pressure on the protruding area of the chest and produces excellent results. Willingness to wear the brace regularly is, however, essential for the success of this treatment approach. The brace works in much the same way as orthodontics in the correction of teeth alignment. The brace consists of front and back compression plates that are anchored to aluminum bars. These bars are bound together by a tightening mechanism which varies from device to device. The brace is easily hidden under clothing and must be worn from 14 to 24 hours a day. The wearing time varies with each brace manufacturer and the managing physicians protocol which could be based on the severity of the deformity.The brace is often worn on the skin or it may be worn over a body sleeve, designed to be worn under the brace. Bracing is becoming a popular treatment method for Pectus Carinatum, mostly due to eliminating the risks accompanying surgery and its proven success.
For patients with more severe cases of Pectus Carinatum, surgery may be required. However bracing could and may still be the first line of treatment. Some severe cases treated with bracing may result in enough improvement that patient no longer needs surgery. The most commonly adopted surgical methods are the Reverse Nuss Procedure or the Ravitch technique.
After adolescence, some men and women use bodybuilding as a means to mask their deformity. Equally, some women find that their breasts serve the same purpose. Some plastic surgeons perform breast augmentation to disguise mild to moderate cases in women.