Overview

Pectus excavatum (PE) is a condition that affects 1 in 300 people and is characterised by indented ribs and sternum (breastbone), making the chest appear caved-in. It is possible to be born with this condition, however, symptoms can develop during puberty and worsen during growth spurts. PE may be mild or severe, with severe cases causing lung or heart problems.¹

Heart problems are a common symptom of severe PE due to the extra pressure that is being exerted on the heart by the indented rib cage and sternum, often leading to exercise intolerance, chest pain and fatigue. 

Causes

PE is caused by an overgrowth of connective tissue that binds the ribs and sternum together, causing them to grow inwards and give the appearance of being caved-in.

There is no specific reason for developing PE but you are more likely to have it if there is a family history of having the condition, or if you have a pre-existing medical condition such as:²

• Scoliosis 
• Noonan Syndrome 
• Marfan Syndrome
• Rickets

Why does pectus excavatum cause heart problems?

When the ribs and sternum are indented they put pressure on the lungs and heart, which can cause the heart to become compressed and pushed more to one side. This may lead to distortion of the cardiac chambers and great blood vessels. Conditions caused by distortion and consistent compression of the heart with a prevalence in individuals with PE are:

• Mitral valve regurgitation – caused by the valve leaflets (flaps of tissue) being unable to properly close during each heartbeat, which might allow blood to leak back into the left atrium
• Arrhythmias – e.g. supraventricular arrhythmia, or in rarer cases, ventricular arrhythmia. These are both abnormal heartbeats that cause the heart to beat faster than it should⁴
• Cardiomyopathy – the general term for a group of heart conditions that affect the structure of the heart, reducing its ability to pump blood efficiently around the body
• Aortic root dilation or aortic root aneurysm – when the first section of the aorta becomes enlarged and has the possibility of tearing or rupturing⁵ 

Research shows that it is common for individuals with PE to have abnormal electrocardiographic readings and that the reason for this is due to the different placement and rotation of the heart within the chest.  

Diagnosis

Diagnosis of PE is typically carried out during a physical examination by a doctor. Further tests may be necessary to supplement the diagnosis, such as:

• X-ray 
• Chest MRI
• Echocardiogram (ultrasound scan of the heart)
• Pulmonary function test
• Cardiopulmonary exercise test

Management and treatment

PE treatment depends on the severity of chest indentation, with mild cases not requiring any treatment. Severe cases of PE may require surgery to correct the structure of their ribs and sternum, which is done by one of two possible surgeries: the Nuss procedure or the Ravitch procedure. 

The Nuss procedure is a minimally invasive surgery in which one or two curved steel bars are placed behind the sternum to push it into the correct shape.  The bars will remain in for 2-5 years depending on age and severity of the condition, however, some patients may choose to keep the bars permanently to reduce the risk of their sternum and ribs returning to their previous state.⁶ 

The Ravitch procedure is a surgical process in which the abnormal cartilage is removed from the sternum and ribcage, allowing the regrowth of cartilage in a more anatomically correct fashion. A metal bar may be added to stabilise the sternum, but this will be removed after approximately 6 months.⁷ 

Surgical corrections of PE are considered the ‘go-to’ treatment in the reduction of consistent heart compression. Exercise capacity has been found to increase in patients who have undergone the Nuss procedure, improving their maximal oxygen uptake by 40.6%.^4,8  

A non-surgical method of treatment is the Vacuum Bell (VB), where a suction cup is used to create a vacuum on the chest wall, causing the sternum to lift and remain that way for a period of time. This procedure can be carried out by the patient a minimum of twice a day for 30 minutes and is activated by a hand pump. VB can be used as a pre-surgery treatment but is beneficial on its own and may allow some patients to avoid surgery altogether.⁹

Complications and prognosis

As we now know, severe cases of PE can result in the compression of the heart which may cause it to be squeezed further to one side of the chest. Consistent compression of the heart puts strain on the cardiovascular system, restricting the appropriate flow of oxygen to the body, and, as a result, increasing thet risk of developing a heart condition. 

In less severe cases, PE can cause psychological issues for patients. Receiving treatment for purely cosmetic reasons is completely valid and should be considered to improve the overall physical and mental wellbeing of the person. 

The general prognosis of those with PE is good. PE on its own does not directly affect the life expectancy of an individual, though the associated heart conditions may do.  Therefore, treatment of PE greatly helps to reduce the risk of developing cardiovascular disorders and may improve life expectancy. 

Summary

Pectus excavatum (PE) is a chest wall disorder where the ribs and sternum grow inwards, causing the chest to appear caved in. This disorder can be mild or severe, with severe cases causing heart problems such as arrhythmias, mitral valve prolapse, cardiomyopathy or dilation of the aortic root. Heart problems are a common symptom of PE due to the consistent compression and altered anatomical positioning caused by the indented sternum, however surgical treatment can be used to alleviate the stress on the heart. 

There are two main types of surgery, the Nuss procedure and the Ravitch procedure, performed by adding a steel bar behind the sternum to correct the shape, and removing the abnormal cartilage to allow it to grow back normally. A doctor will recommend the best surgery for the affected person, depending on the severity of the disorder, age, and lifestyle of the individual.

A non-surgical route is the use of a Vacuum Bell (VB) where a suction cup is attached to the front of the chest, allowing the vacuum to lift the sternum. This method provides clear and quick results as it can be used at home for a number of hours per day. 

Treatment and management of PE is extremely important in achieving a good prognosis, regardless of the severity of the disorder. There are both physiological and psychological benefits to receiving surgical or non-surgical treatment.¹⁰