The chest wall deformities pectus excavatum and carinatum have incidences of approximately one in 500 and 1,500 respectively. Here, Jay M. Wilson, MD, senior associate in Children’s Hospital Boston’s Department of Surgery, discusses the range of severity, available treatments and psycho-social impact of the condition.
Both are apparent during physical exams. Excavatum is an indentation of the chest wall. Carinatum is a protuberance of the chest wall. Either may run the gamut from barely perceptible to severe. I’ve seen indentations of a chest wall that could hold a quart of water, while others are characterized by only a few millimeters’ depression. They may taper gradually or draw to a sudden peak or depression. Asymmetry is fairly common and a combination of excavatum and carinatum is possible.
We can often see both deformities in newborns and during early childhood. Other times, though, it may not be apparent until the child is 9 or 10. It’s rare for either excavatum or carinatum to show up after that. The typical course is from mild to more severe, with growth spurts contributing most to severity.
They’re unknown. Some studies investigating a genetic component are underway. Although the majority of cases don’t involve a family history, there are many that do—enough to warrant the suspicion that genes play a significant role. The genetic story is likely to be complex, though.
Excavatum is amenable to surgical repair. The first option is called the Welsh, during which the surgeon makes an incision in the chest wall, removes the cartilage wedged between the ribs and breastbone, and then repositions the freed up breastbone as appropriate. A bar is left in the chest wall to maintain the right shape for six months, during which time the child has to refrain from activities that might involve a collision, like football. The technique leaves a scar visible on the chest, but allows for a precise resolution of asymmetries.
With a technique called the Nuss, the incisions are made on the side, a bar is inserted laterally through the chest and the breastbone is lifted forward. No cartilage is removed. Scarring is less extensive. On the other hand, any asymmetry that’s there pre-operatively will remain post-operatively to some degree. And although we’re not breaking and resetting bones like we are in the Welsh, there’s as much pain throughout recovery. Also, the bar has to stay in for at least a year, and sometimes two. Surgeons at Children’s specialize in both techniques.
Twenty-five years ago, surgeons operated when the child was as young as 4. The cartilage content of the bones made repositioning easier and healing was faster. But too often, the condition would recur, especially during growth spurts. So we prefer to intervene, if we intervene at all, during the child’s teen years. By then, they have most of their vertical height. One more growth spurt won’t contribute much to a recurrence. As for resolving carinatum, we recommend bracing, as pressure over time reforms the chest wall.
For mild cases of either condition, there’s really no reason for intervention. A shallow excavatum is unlikely to affect the operation of the heart or lungs at all. A mild carinatum, if anything, gives the thoracic organs more room to function. Appearance, too, is normal in these cases.
In more severe cases, the approach is different. A severe excavatum can impinge on the heart and lungs, but it’s important not to overstate the threat. At extremes of exercise, there is a slight deficit in the heart’s stroke volume, and the volume of blood the heart can pump out with each beat. That’s because the heart has less room to fill when it relaxes. Pulmonary function tests also show a slight deficit in severe cases of excavatum. But again, this occurs only at extremes of exercise. These kids are not at any elevated risk for sudden death. With severe cases of carinatum, the problem is one of form rather than physiology. In both cases, the emotional impact can be devastating. Some kids with severe pectus are perfectly content with the shape of their chests. But those who suffer psychologically can suffer deeply.
It’s not yet clear whether surgical repair of excavatum really improves physiology. When we intervene at around age 12 or 13, when the lungs are already fully formed and the heart is almost fully formed. But the change in appearance can be drastic. For basic moral reasons and demonstrable psycho-social ones, we believe every child has a right to a normal appearance.
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