Pectus excavatum is a common congenital chest wall deformity where the sternum (breastbone) and attached ribs grow inward, creating a sunken appearance in the chest. Often called “funnel chest,” the condition varies greatly, ranging from a mild dip to a deep, asymmetrical depression that becomes more pronounced during adolescent growth spurts. Whether pectus excavatum is a serious health concern depends entirely on the severity of the inward growth and its effect on internal chest structures. For many, the condition is primarily aesthetic, but moderate to severe cases can significantly diminish physical and psychological well-being.
Understanding the Physiological Impact
The primary concern with a sunken chest is the physical compression or displacement of the organs situated directly behind the sternum, namely the heart and lungs. When the breastbone is pushed backward, the reduced space within the thoracic cavity can impede normal cardiopulmonary function, especially during periods of high demand.
The cardiac effects are often characterized by heart displacement, usually shifting the organ to the left side of the chest. This physical restriction limits the heart’s ability to fill completely with blood, known as reduced ventricular filling space. Consequently, the stroke volume—the amount of blood pumped out with each beat—may be lower than normal during strenuous exercise, leading to a reduced cardiac output. This limitation often manifests as exertional dyspnea (shortness of breath) and decreased endurance during physical activity.
Pulmonary function can also be compromised as the rigid, inward-caved chest wall restricts the lungs from fully expanding. This restriction causes a pattern similar to restrictive lung disease, limiting the maximum amount of air the lungs can hold (total lung capacity). The reduced chest wall compliance means a person must work harder to breathe, which contributes to fatigue. Correcting the deformity can improve both pulmonary function and exercise tolerance, confirming the mechanical restriction imposed by the sunken sternum.
Determining Severity and Functional Limitation
Physicians use objective measurements and diagnostic tests to determine if the deformity has progressed to a point that warrants intervention. The most recognized radiological determinant of severity is the Haller Index (HI), calculated from a cross-sectional image of the chest, typically a Computed Tomography (CT) scan. The HI is a ratio of the transverse width of the chest cavity divided by the shortest distance from the back of the sternum to the front of the spine.
A normal chest has a Haller Index below 2.5, while a value of 3.25 or greater is the accepted threshold for defining a severe deformity considered for surgical correction. Functional limitation is confirmed through specialized tests. These commonly include Pulmonary Function Tests (PFTs), which measure lung capacity and air flow, and echocardiograms or cardiac Magnetic Resonance Imaging (MRI) to assess ventricular compression and function. These evaluations bridge the gap between the physical appearance of the chest and the actual impact on the patient’s heart and lungs.
Addressing Psychological and Cosmetic Concerns
While physical impairment is a major consideration, the psychological and emotional impact of pectus excavatum can be equally detrimental to a person’s health, particularly during adolescence. The highly visible nature of the deformity often leads to significant body image issues and low self-esteem. Individuals may feel “different” from their peers, which can result in social anxiety and withdrawal from activities that require removing a shirt, such as swimming or sports.
The constant worry about one’s appearance can manifest as shyness and a reluctance to engage in social interactions. This psychological distress is a valid health concern that, even in the absence of severe physical symptoms, can be a primary motivation for seeking treatment. Studies have shown that surgical correction can lead to a significant improvement in body image and self-esteem.
Intervention: When Treatment is Necessary
The decision to treat pectus excavatum is based on a combined assessment of the Haller Index, documented functional impairment, and the degree of quality-of-life impact.
For patients with a mild deformity and a flexible chest wall, non-surgical management is an option. This approach often involves the use of a Vacuum Bell device, a non-invasive tool that creates suction to gradually lift the sternum forward over a period of many months or years. The Vacuum Bell is best suited for younger patients with mild to moderate deformities.
When the deformity is severe (HI \(\ge\) 3.25) or when significant cardiopulmonary dysfunction is confirmed, surgical repair is generally recommended. The most common procedure is the Minimally Invasive Repair of Pectus Excavatum (MIRPE), widely known as the Nuss Procedure. This technique involves inserting a curved metal bar through small incisions on the sides of the chest, which is then flipped to push the sternum outward into a corrected position. The bar remains in place for two to three years before removal.
An alternative, older technique is the Modified Ravitch Procedure, which is an open surgical approach. This operation involves making a larger incision, removing the abnormally grown costal cartilage, and then repositioning the sternum, sometimes using a metal strut or plate for support. While the Nuss procedure is favored for its minimally invasive nature, the Ravitch technique may be preferred for older patients or those with more complex, asymmetrical, or recurrent deformities. Ultimately, treatment is necessary when the risk of organ compression is high, or when the psychological burden significantly impairs the individual’s quality of life.