What is Pectus excavatum

TL;DR: Pectus excavatum is a congenital structural deformity of the chest wall characterized by a sunken or "caved-in" appearance of the sternum (breastbone). While it is often primarily a cosmetic concern, severe cases can affect cardiopulmonary function by reducing the space available for the heart and lungs to operate efficiently.

What exactly is Pectus excavatum?

Pectus excavatum is the most common congenital chest wall deformity, occurring when the sternum grows inward toward the spine. This creates a visible depression in the center of the chest. While many individuals with Pectus excavatum experience no physical symptoms, the inward displacement of the breastbone can compress the thoracic cavity. In our community at DiseaseMaps.org, 81 members have shared their experiences, highlighting that the impact of Pectus excavatum can range from mild aesthetic concerns to significant physical limitations affecting daily life and exercise tolerance.

How does Pectus excavatum affect the body?

The primary impact of Pectus excavatum is on the musculoskeletal system, but it frequently involves secondary effects on the cardiovascular and respiratory systems. When the sternum is severely depressed, it may push the heart toward the left side of the chest (mediastinal shift) or compress the right ventricle. This can lead to reduced cardiac output during intense physical exertion. Similarly, the reduced volume of the thoracic cavity can limit lung expansion, potentially resulting in decreased vital capacity and shortness of breath during activity.

Who is typically affected by Pectus excavatum?

Pectus excavatum is estimated to occur in approximately 1 in every 300 to 1,000 births. It is notably more common in males than in females, with a reported male-to-female ratio of approximately 3:1. While the condition is congenital—meaning it is present at birth—the deformity often becomes significantly more pronounced during the rapid growth spurts of puberty. There are no known geographic factors that significantly influence the prevalence of Pectus excavatum.

What causes this chest wall deformity?

The exact underlying mechanism of Pectus excavatum remains a subject of ongoing research, though it is widely believed to be caused by an overgrowth of the costal cartilages that connect the ribs to the sternum. This excessive growth pushes the sternum inward. While most cases are sporadic, approximately 35% to 45% of patients report a family history, suggesting a genetic component. It is also frequently associated with connective tissue disorders, such as Marfan syndrome or Ehlers-Danlos syndrome.

Key facts and clinical differentiators

It is important to distinguish Pectus excavatum from other chest wall conditions to ensure proper management. Key clinical features include:

• Symmetry vs. Asymmetry: The depression may be symmetric (centered) or asymmetric (deeper on one side).


• Progression: Unlike some other skeletal deformities, this condition typically worsens during adolescent growth spurts before stabilizing.


• Associated Conditions: It is often screened for alongside scoliosis, which occurs in a significant subset of patients.


• Diagnostic Imaging: Diagnosis is typically confirmed via physical exam, but surgeons often use a Haller Index (measured via CT or MRI) to quantify the severity by comparing the width of the chest to the distance between the sternum and the spine.

Next steps

• Consult a pediatric surgeon or a thoracic surgeon who specializes in chest wall deformities to assess your Haller Index.


• Monitor for symptoms such as exercise intolerance, chest pain, or persistent shortness of breath.


• Join the DiseaseMaps.org community to connect with the 81 other members who are navigating life with this condition.


• Request a referral to a cardiologist for an echocardiogram if you are experiencing palpitations or reduced stamina.

Medical disclaimer: This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Pectus excavatum.


• Orphanet: Congenital chest wall malformations.


• OMIM (Online Mendelian Inheritance in Man): Pectus excavatum entry.


• National Library of Medicine (PubMed): Clinical reviews on the pathophysiology of pectus deformities.