19: Congenital Chest Wall Anomalies

Epidemiology

• Pectus excavatum occurs in about 1:400 live births, with a male predominance of up to 5:1. No genetic abnormalities or chromosomal aberrations have been associated with pectus excavatum, although a familial tendency has been described. Up to two-thirds of children with Marfan’s syndrome and a large proportion of Ehlers–Danlos patients develop pectus excavatum deformities. The incidence of pectus carinatum is about one-tenth that of pectus excavatum, with a similar male predominance and 25 to 30 percent reported family history. Scoliosis and other spinal deformities or a family history of these are associated with pectus carinatum.

Pathophysiology

• Pectus excavatum is a concave depression of the sternum resulting from abnormal growth, lengthening, rotation, or increased elasticity of the costal cartilages. Reduced cardiovascular performance has been linked to this defect. Pectus carinatum results from anterior displacement of the costal cartilages due to rotation and lengthening, leading to sternal protrusion. No significant cardiopulmonary abnormalities have been demonstrated with this lesion.

Clinical features

• In pectus excavatum, the sternum is posteriorly retracted and differential growth of the costal cartilages often results in an asymmetric chest wall with a common right-sided rotation of the sternum and an elevated left side. Other characteristic findings include sloped ribs, rounded shoulders with a classic stooped posture, and a protuberant abdomen. It is most commonly discovered in the first few years of life. Decreased stamina and endurance during exercise and excessive tachycardia/palpitations are commonly observed with this disorder. Pain is occasionally associated with this defect. Pectus carinatum is associated with pain, respiratory symptoms, ease of injury, and psychosocial body image concerns.

Diagnostics

• The best radiographic imaging modality for pectus deformities is the computed tomographic scan of the chest, which provides precise information regarding cardiac displacement, lung volumes, the degree of deformity, and any associated malformations.

Treatment

• Surgical correction of pectus excavatum includes the modified Ravitch repair (subperichondrial resection of all abnormal costal cartilages and wedge osteotomy to correct the posterior depression of the sternum by bringing it to a more anterior and neutral position) and the Nuss repair (using a precurved substernal bar to bend the sternum and cartilages to a corrected position). Surgical correction for pectus carinatum utilizes the basic principles employed in the open Ravitch repair, namely excision of all abnormal cartilages and return of the sternum to a neutral straight position.

Outcomes/prognosis

• The modified Ravitch or Nuss repairs represent the “gold standard” corrective operation for pectus excavatum. Hospitalization rarely exceeds 3 days, and 97 percent of patients experience a good result from the operation. Similar success rates are reported for Ravitch-type repairs of pectus carinatum. Complications include recurrence, pneumothorax, wound infection, atelectasis, and local tissue necrosis.