Pectus Excavatum
Clinical Manifestations and Treatment of a Congenital Caved-In Chest
The congenital musculoskeletal disorder known as pectus excavatum can be mild or serious and requires surgical intervention.
Although chest wall abnormalities that appear since birth are not common, pectus excavatum is the most common of these congenital chest wall deformities. It is defined as a breastbone (sternum) that appears sunken into the chest. The problems associated with this condition are more than just cosmetic.
Pathogenesis, Symptoms, and Signs
Although pectus excavatum is believed to be the result of abnormal bone and cartilage growth, the mechanism of this process is not certain. In any event, patients generally have psychological stress from his or her abnormal chest appearance. Some patients may not have symptoms, particularly when they are young. Others, however, may have difficulty breathing as a result of compression of the lung and/or heart.
The condition is diagnosed by physical examination and evaluated further by a CT scan of the chest. By measuring the chest diameter in two directions and calculating a ratio called the Haller index, the severity of pectus excavatum can be determined. Surgical correction is warranted if the Haller index is greater than 3.2. Otherwise, the patient can simply be observed and managed medically for any complications.
Treatment
There are two standard surgical procedures for pectus excavatum. The Ravitch procedure is an open surgical technique involving the removal of abnormal cartilage and placement of a metal bar. The Nuss procedure is another technique in which the surgeon makes incisions in the sides of the chest, uses an instrument through the chest cavity to force the sternum forward, and introduces a long curved bar into the chest cavity to hold the sternum in place. With either procedure, the bar is left in the patient's chest for at least a year before it is removed. Evidence has shown that surgical correction of pectus excavatum improves pulmonary and cardiac function. The prognosis after the procedure is usually good.
Meanwhile, there is one treatment currently under investigation. Pediatric surgeons at the University of California, San Francisco, have devised a treatment for pectus excavatum involving magnets. Termed the Magnetic Mini-Mover Procedure (3MP), the patient has a magnet surgically attached to the front of the sternum under the skin and wears a separate chest brace suspending an external magnet. The force of attraction between the two magnets is believed to gradually pull the sternum forward over time. To date, a clinical trial for the 3MP is still underway, which will determine the safety and efficacy of this novel treatment.
