Pectus Excavatum (Cave Deformity): Causes, Symptoms, Diagnosis, and Treatment

What is cave deformity?

Cave deformity, medically known as Pectus Excavatum, is a congenital chest wall malformation characterized by an abnormal indentation or caving-in of the sternum (breastbone) and rib cage, often giving the chest a sunken appearance.

Understanding Cave Deformity

Pectus excavatum, commonly referred to as "cave deformity" or "funnel chest," is the most common congenital deformity of the anterior chest wall. It results from an abnormal growth of the costal cartilages (the cartilage connecting the ribs to the sternum), which causes the sternum to be pushed inward towards the spine. This can range from a mild, almost imperceptible dip to a severe, deep depression that may compress the heart and lungs.

The condition is typically noticeable at birth or becomes more pronounced during growth spurts in early adolescence. While primarily a cosmetic concern for many, severe cases can lead to functional impairments affecting the cardiovascular and respiratory systems.

Causes and Risk Factors

The exact cause of pectus excavatum is often unknown, meaning it is idiopathic in most cases. However, several factors are believed to contribute to its development:

• Genetic Predisposition: There is a strong familial tendency, suggesting a genetic component. Approximately 30-40% of individuals with pectus excavatum have a family history of the condition.
• Connective Tissue Disorders: Pectus excavatum is frequently associated with certain genetic syndromes that affect connective tissue, such as:
  • Marfan Syndrome: A disorder affecting connective tissue, leading to issues with the heart, eyes, blood vessels, and skeleton.
  • Ehlers-Danlos Syndrome: A group of inherited disorders that affect connective tissues, primarily skin, joints, and blood vessel walls.
  • Poland Syndrome: A rare birth defect characterized by missing or underdeveloped muscles on one side of the body, often accompanied by chest wall deformities.
• Rapid Growth: The deformity often becomes more prominent during periods of rapid growth, such as adolescence, indicating a potential interplay between growth mechanics and cartilage development.

Signs and Symptoms

The signs and symptoms of cave deformity vary widely depending on the severity of the sternal depression.

• Physical Appearance:
  • A visible indentation or depression in the center or lower part of the chest.
  • Often asymmetrical, with one side of the chest appearing more sunken than the other.
  • Flared ribs (costal flaring) may be present, where the lower ribs protrude outwards.
  • Poor posture, including rounded shoulders and a forward head posture, may develop as a compensatory mechanism.
• Cardiopulmonary Symptoms (more common in severe cases):
  • Shortness of Breath (Dyspnea): Especially during physical exertion, due to reduced lung capacity.
  • Chest Pain: Can be sharp or dull, and may be related to sternal compression or muscular strain.
  • Heart Palpitations: A feeling of a rapid, fluttering, or pounding heart.
  • Reduced Exercise Tolerance: Difficulty keeping up with peers during physical activities.
  • Fatigue: General tiredness due to inefficient breathing and circulation.
  • Recurrent Respiratory Infections: In some severe cases, compromised lung function can lead to increased susceptibility.
• Psychological Impact:
  • Body Image Issues: Significant self-consciousness and anxiety about appearance, especially during adolescence.
  • Social Avoidance: Reluctance to participate in activities that expose the chest, such as swimming or sports.
  • Depression and Low Self-Esteem: Can result from chronic body image concerns.

Diagnosis

Diagnosis of pectus excavatum typically involves a combination of physical examination and imaging studies.

• Physical Examination: A thorough visual inspection and palpation of the chest wall helps to assess the depth and symmetry of the indentation, as well as any associated postural changes.
• Imaging Studies:
  • Chest X-ray: Provides an initial assessment and can help rule out other conditions. It can also be used to calculate the Haller Index (a ratio of the transverse diameter of the chest to the shortest distance between the sternum and the spine), which quantifies the severity of the depression.
  • Computed Tomography (CT) Scan: The gold standard for detailed anatomical assessment. A CT scan provides precise measurements of the deformity, including the Haller Index, and helps evaluate the degree of compression on the heart and lungs.
  • Magnetic Resonance Imaging (MRI): Can be used as an alternative to CT, especially in younger patients, to avoid radiation exposure.
• Functional Tests (especially for symptomatic individuals):
  • Pulmonary Function Tests (PFTs): Measure lung volume and airflow to assess respiratory capacity and efficiency.
  • Echocardiogram: An ultrasound of the heart to evaluate cardiac function and assess for any compression or displacement of the heart.
  • Exercise Stress Test: Evaluates the individual's exercise capacity and identifies any limitations or symptoms that arise during physical exertion.

Treatment Approaches

Treatment for pectus excavatum depends on the severity of the deformity, the presence of symptoms, and the individual's age and preferences. Options range from conservative management to surgical correction.

• Conservative Management:
  • Physical Therapy: Focuses on improving posture, strengthening core and back muscles, and enhancing breathing mechanics through specific exercises. This can help mitigate some of the postural compensation and improve chest wall mobility.
  • Vacuum Bell Therapy: A non-surgical device that creates a vacuum over the sternum, gradually pulling the chest wall outward. It is typically used for mild to moderate cases, requires consistent daily use over several months to years, and is more effective in younger patients whose cartilage is more pliable.
  • Exercise and Strength Training: While it cannot correct the bone deformity, targeted exercises can improve muscle balance, strengthen the chest and back, and enhance overall fitness. Activities like swimming, rowing, and specific resistance exercises for the chest and back can be beneficial.
• Surgical Correction:
  • Nuss Procedure (Minimally Invasive Repair of Pectus Excavatum - MIRPE): The most common surgical approach. Small incisions are made on each side of the chest, and a curved metal bar (or bars) is inserted under the sternum, flipping it outwards. The bar remains in place for 2-4 years before being removed. This procedure is less invasive, results in less scarring, and typically has a faster recovery than open surgery.
  • Ravitch Procedure (Modified Open Repair): An older, more invasive technique where an incision is made down the center of the chest. The deformed costal cartilages are removed, and the sternum is repositioned and stabilized, sometimes with a temporary support bar or mesh. This procedure is typically reserved for complex or recurrent cases.

Surgical intervention is generally considered for individuals with significant symptoms (cardiopulmonary compromise), severe deformities (high Haller Index), or considerable psychological distress due to the appearance.

Living with Cave Deformity: Management and Outlook

For many individuals, living with pectus excavatum involves managing its physical and psychological aspects.

• Exercise Considerations: Individuals with pectus excavatum, whether treated or not, can generally lead active lives. For those with mild cases, regular exercise, particularly activities that promote good posture, strengthen the core and back, and improve cardiorespiratory fitness, are beneficial. Post-surgery, a structured rehabilitation program is crucial to restore full function and flexibility.
• Monitoring: Regular follow-up with a physician is important, especially for children and adolescents, to monitor the progression of the deformity and any associated symptoms.
• Psychological Support: Given the potential impact on body image and self-esteem, psychological counseling or support groups can be invaluable, particularly for adolescents, to help them cope with the condition and improve their confidence.
• Prognosis: The prognosis for individuals with pectus excavatum is generally excellent. With appropriate treatment, especially surgical correction for severe cases, individuals can experience significant improvements in cardiopulmonary function, posture, and body image, leading to a better quality of life.