Chapter 140: Overview: Benign Disorders of Chest Wall

INTRODUCTION

This section on chest wall disorders encompasses benign disorders of the skeletal and muscular chest wall (Fig. 140-1), including congenital deformities of the chest wall, a group of compressive disorders known collectively as thoracic outlet syndrome, autonomic disorder involving the sympathetic nerve, chest wall infections, and benign chest wall tumors.

CHEST WALL DEFORMITIES

Congenital chest wall deformities may be categorized as (1) pectus excavatum, (2) pectus carinatum, (3) Poland syndrome, (4) sternal defects, and (5) miscellaneous anterior chest wall defects. While most patients present during childhood, some may present in early adulthood with these ailments.

Pectus Excavatum

Pectus excavatum, or “funnel chest,” is a congenital deformity characterized by posterior depression of the middle to inferior portion of the sternum and posterior curvature of the associated costal cartilages (Fig. 140-2). Generally, the manubrium and first and second ribs are normal. The severity of the depression varies and is usually asymmetric with a deviation to the right side. Shamberger and Welch reported that the majority of cases (86%) are diagnosed at or within a few weeks of birth.¹ Although it was once commonly believed that children would “outgrow” this deformity, the severity of the sternal depression may increase during periods of rapid growth and surgical correction is often required.

Pectus excavatum is the most common congenital chest wall deformity in children, with a reported incidence of 1 in 400 to 1 in 1000 live births. A male predominance is observed, with boys reported to be affected three to five times more often than girls.² The etiology of pectus excavatum is unknown. Theories encompass abnormal cartilage development, intrauterine pressure, rickets, and abnormalities of the diaphragm, including congenital diaphragmatic hernia and diaphragmatic agenesis.^3,4 Genetics are thought to pose an influence due to occasionally reported familial inheritance patterns.^4,5 Shamberger and Welch note that 35% of patients report a positive family history for chest wall deformities.¹

Pectus excavatum is usually sporadic, but it may be accompanied by other abnormalities. In a study of 327 patients with pectus excavatum, musculoskeletal abnormalities such as scoliosis were identified in 21%. Pectus excavatum has been associated with congenital heart defects (1.5%) and connective tissue disorders such as Marfan syndrome or Ehlers-Danlos syndrome in up to 6.4%.⁶ Although many pediatric patients are asymptomatic, symptoms can worsen with age, increased physical activity, or worsening of deformity during the adolescent growth spurt.⁷ A recent multicenter prospective trial demonstrated that approximately two-thirds of patients reported dyspnea or other chest symptoms ...