Pectus excavatum (PE), often called “funnel chest,” is the most common congenital chest wall deformity, characterized by an abnormal inward growth of the breastbone. This results in a concave or sunken appearance of the anterior chest wall. The condition is present at birth, though it often becomes more noticeable and pronounced during adolescent growth spurts. While many cases are mild and primarily a cosmetic concern, a significant depression of the sternum can affect the space available for the heart and lungs.
Assessing the Risk Level
For the majority of individuals, pectus excavatum is a mild condition that poses no significant health danger. The primary issue in these cases is often psychological distress or concern over body image, particularly during adolescence.
However, the severity of the deformity exists on a spectrum, and a minority of cases can be severe enough to cause serious physiological complications. When the inward pressure of the sternum is substantial, it can physically compromise the internal organs, leading to functional impairment that necessitates medical assessment and potential intervention. This physical impact determines when the condition shifts from a cosmetic issue to a health concern.
Impact on Cardiopulmonary Function
Severe pectus excavatum causes danger by physically reducing the volume of the chest cavity, directly affecting the heart and lungs. The sunken sternum can displace the heart, typically pushing it toward the left side of the chest. This displacement and compression can hinder the heart’s ability to fill with blood effectively, particularly the right ventricle.
This compression can result in a measurable decrease in the heart’s end-diastolic volume. While the heart may function normally at rest, this restriction becomes apparent during physical activity, manifesting as a reduced stroke volume and overall cardiac output under strenuous conditions. The cardiopulmonary system attempts to compensate for this reduced efficiency by increasing the heart rate at lower levels of exercise than normal.
The deformity also imposes restrictions on the pulmonary system, limiting the lungs’ ability to fully expand. Although resting lung volumes are often within the normal range, the reduced chest wall compliance can cause mild air-trapping and contribute to a restrictive breathing pattern. This reduced lung capacity, combined with the cardiac limitations, directly contributes to the most common physical symptom: exercise intolerance.
Identifying Critical Symptoms and Severity
The presence of certain symptoms is a strong indicator that pectus excavatum has become severe enough to warrant medical intervention. These symptoms include shortness of breath, particularly with exertion, and a loss of endurance. Patients may also report chest pain, heart palpitations, or a fast-beating heart, which are signs of cardiac compromise.
Beyond subjective symptoms, the severity is objectively quantified using the Haller Index (HI), a measurement derived from a computed tomography (CT) scan. The HI is calculated by dividing the maximum transverse width of the chest by the minimum anteroposterior distance at the point of greatest sternal depression. A normal chest typically has an HI of 2.5 or less.
A Haller Index greater than 3.25 is considered severe and is often a standard criterion for surgical correction. An index exceeding 3.5 is categorized as severe excavatum. Imaging studies like CT scans and echocardiograms also play a role, as they can visually confirm right-sided cardiac compression and heart displacement, providing evidence that internal organs are compromised.
Remedial Strategies and Treatment
The management approach for pectus excavatum depends on the degree of severity and the presence of functional symptoms. For mild cases without cardiopulmonary impairment, non-surgical approaches are recommended, focusing on regular monitoring and sometimes physical therapy to improve posture. These strategies address the cosmetic and minor physical concerns without invasive procedures.
In cases where the Haller Index is high (3.25 or greater) and symptoms like exercise intolerance or cardiac compression are present, surgical correction is the standard treatment.
Surgical Procedures
The minimally invasive Nuss procedure involves inserting a curved metal bar beneath the sternum to push it outward, where it remains for two to three years. Alternatively, the Ravitch procedure is an open surgery that involves removing abnormal cartilage and surgically repositioning the sternum, often using a metal strut for support.