What are pectus excavatum and pectus carinatum?
Pectus deformities occur in one to eight in 1,000 people and are more frequent in boys than in girls. In pectus excavatum (funnel chest), the sternum (breastbone) is depressed in a concave shape, and in pectus carinatum (pigeon chest), the sternum protrudes in a convex shape. The chest may look uneven. The deformity varies in severity, ranging from a mild to severe indentation or protrusion. For example, a patient with a severe pectus excavatum may have only a few inches between his or her sternum and spine. Most patients have a slim chest and a slouching posture, and younger children commonly have potbellies.
What causes pectus excavatum and pectus carinatum?
The deformity is thought to be caused by excessive growth of the costal cartilages (ribs), although the reason for this is unknown. This overgrowth causes the ribs and cartilages to buckle and pushes the sternum either inward or outward. Musculoskeletal abnormalities that are associated with pectus deformities are scoliosis (lateral curvature of the spine), Marfan’s syndrome (an inheritable disorder of the connective tissue) and Poland’s syndrome.
Does the deformity become better or worse with age?
The deformity is often noticeable at birth but becomes more apparent during the period of rapid skeletal growth in early adolescence. After the age of approximately 18, the deformity remains the same. Gaining weight and chest hair in men usually reduce the appearance of the deformity.
What are the symptoms associated with these conditions?
Sometimes, no symptoms are noticed until the child participates in athletic or high-stress activities. As children, individuals with these defects are shy and many times will not participate in activities requiring their chest to be exposed, such as in swimming or athletic events. As the child grows older, the symptoms – becoming easily fatigued and decreased stamina and endurance – become apparent, especially during competitive athletics. Also, adults in their twenties and thirties, as well as elderly adults, become very aware of this problem. If they have not participated in physical activities during high school, fitness programs produce easy fatigue and cardiac arrhythmias and tachycardias (very fast heart rate) during extensive physical or strenuous exercise.
Moderate to very severe defects, in which the heart is displaced to the left of the sternum, or the midline, place undue pressure on the lung artery or pulmonary artery, which carries blood from the heart to the lungs. This may cause a murmur, which is due to the pressure on the system causing rough, instead of smooth, flow. An EKG also can demonstrate strain on the right side of the heart. The expansion of the lungs during breathing or exercise, which is important in maintaining normal respiratory function, is confined because the chest wall cannot expand. Thus, a more intensive and rapid respiratory rate is necessary. Also, the diaphragm must make larger movements to provide enough oxygen and carbon dioxide exchange to meet the body’s demand under exercise conditions. More energy is required, and this contributes to fatigue in contrast to the physical state of the normal individual.
In addition, there is an increased incidence of respiratory infections and asthma. Almost all of these individuals have a body configuration of rounded shoulders and a potbelly. Front and lateral-view X-rays of the chest demonstrate the defect and displacement of the heart to the left of the midline, as well as compression of the right ventricle.
How can his defect be tested?
In most instances, conventional pulmonary function tests or cardiac catheterizations to measure cardiac output and function are normal with the patient at rest. However, if the patients are subjected to upright, intense exercise, the cardiac output usually is decreased when compared to normal individuals of the same age. Also, the respiratory function is reduced. Depending on the severity of the defect, this reduction can be from 10-30%.
After correction of the defects, function returns to near normal in the majority of patients. Also, the heart rate is slower, and the ability to exercise at high levels of energy output is improved. Thus, it is important to recognize that the pectus excavatum deformity is not just a cosmetic problem. Patients with moderate to severe uncorrected deformities usually cannot compete in major activities. The continuous beating of the heart against a firm bone also may lead to arrhythmias (irregular heart beats).
What can be done to correct these conditions?
It is unfortunate that this defect has been thought of as merely cosmetic over a long period. This may be because of the very young patients who frequently don’t show symptoms because they are not involved in full exercise routines. It is not until the teenage and later years that the real symptoms of the defect show up. The ideal age for surgical correction of this defect is anytime after two years of age, with the simplicity of repair in younger people making it the optimal period for repair. The risk of anesthesia is minimal, and psychological problems are avoided.
The standard pectus repair of these deformities has been to operate on both sides of the chest, put a plate behind the sternum and then perform a second operation to remove the plate after a year or so. The surgery takes anywhere from three to five hours and requires four to five days of hospitalization. Over the past 25 years, an operation that does not open the chest and that is combined with a bracing technique has been performed. This operation takes between 45 minutes and an hour in children and requires shorter hospitalization.
The incision is made beneath the breasts, which results in a more desirable scar cosmetically. The lower four to five cartilages (ribs) are removed, and the perichondrium, or the covering of the cartilages, is left in place. Then, a wedge is taken out of the sternum, and, depending on the amount of unevenness, the sternum is tailored according to the defect. A sheathed wire is placed behind the sternum and brought out through the muscles and skin and later attached to a modified brace for a period of six to 12 weeks, depending on severity. During that period, the cartilages reform in the new position, and the defect is completely corrected. The patients are fitted with a brace – a light vest – before surgery, and a wire is attached to the brace during surgery. Patients can return to work or school within a week after surgery. Blood administration is unnecessary. The complete healing period is eight to 12 weeks, after which individuals can return to their normal activities. Recurrence is very unusual with this operation because of the wedge osteotomy and the holding of the position by the wire and vest.
Pectus carinatum, or protrusion of the breast (pigeon breast), is different malformation. The overgrowth of the cartilage (ribs) and forward buckling onto the sternum and secondary pressures cause pain. In most instances, the peak progression of this defect occurs during growth periods, especially in teenagers, and thus, the defect is usually corrected at this time.
The carinatum deformity produces a very rigid chest, so the chest is almost secured in a position near full inspiration (such as when a deep breath is taken). This makes breathing inefficient, and the individual needs to use the diaphragm and accessory muscles for respiration rather than normal chest muscles during strenuous exercise. Here, the heart is in normal position and there is rarely a murmur. However, there is loss of pulmonary function in these individuals, and they tend to develop emphysema and also to have lung infections. In both defects, asthma is not cured by an operation, but certainly the hospitalizations and the need for medications are reduced by the surgical correction. The surgical correction of this defect also involves removing the cartilages (ribs) on both sides and the excess cartilage over the sternum. A reverse wedge is carried out on the sternum, and bracing is performed in a compression system rather than the outward rigging that is required by a pectus excavatum. The surgery takes approximately one hour, and hospitalization is one day.
What are the average results of surgical corrective treatment?
The results of these operations are very good as far as enabling patients to participate in normal strenuous activities and athletics. Also, there is a marked improvement in the patient’s self-image. Many of the small children are teased by their schoolmates, and they become very shy. Many times, kids refuse to take showers with other kids, and during physical education, they refuse to take their shirts off. Repairing the chest deformity, in almost all instances, should allow individuals to participate in a full range of activities.
For an appointment with Washington University pediatric surgeon Martin Keller, MD, who treats chest deformities, call (314) 454-6022, Monday-Friday, 8 a.m.-5 p.m.