Pectus Excavatum

Pectus excavatum (funnel chest) is a congenital depression of the sternum and adjacent costal cartilages. It is the commonest chest wall deformity, found in about 1 in 300 to 400 births, with a male to female ratio of 3 to 5 to 1, and a family history in about a third.

It is usually noticed in infancy, and worsens during the pubertal growth spurt. It occurs alone in most, and with connective tissue disease (Marfan syndrome, Ehlers-Danlos syndrome), scoliosis (in a fifth), Poland syndrome, Noonan syndrome or mitral valve prolapse in some.

Pathophysiology. Overgrowth of the costal cartilages displaces the sternum posteriorly. Depth varies and may be symmetric or asymmetric. Severe depression compresses the right ventricle and displaces the heart to the left, and limits chest wall expansion, reducing stroke volume and lung volumes during exercise.

The deformity is the main finding, with a visible depression of the lower sternum, protruding abdomen, rounded shoulders and sometimes asymmetry. Many have no physical symptoms. Others have exertional dyspnoea, reduced exercise tolerance, fatigue, chest pain, palpitations and a systolic murmur. Psychological effects (self-consciousness, avoidance of sport, anxiety, low mood) are common and often the main concern in adolescents.

• Clinical assessment of depth, symmetry, flexibility and associated features (Marfan habitus, scoliosis, joint laxity, family history).
• CT or MRI of the chest to calculate the Haller index (transverse chest diameter divided by the anteroposterior distance between sternum and spine): normal about 2.5, and over 3.25 indicates severe deformity. MRI avoids radiation in children and is preferred when only assessing severity.
• Spirometry: normal or mildly restrictive (FVC and FEV1 reduced by 10 to 15% in severe cases). Cardiopulmonary exercise testing may show reduced oxygen pulse and peak oxygen uptake.
• Echocardiography for right ventricular compression, displacement and mitral valve prolapse, and electrocardiogram for conduction changes.
• Genetic assessment for connective tissue disease when features suggest it (tall stature, arm span, lens dislocation, aortic root dilatation).
• Spinal examination for scoliosis.

• Mild and asymptomatic: observation, posture advice, breathing exercises and regular aerobic exercise, with annual review through growth.
• Vacuum bell (negative pressure suction device) in flexible deformities: applied for 30 minutes to 1 hour twice daily, or 2 to 3 times a day in the early phase, for at least 6 to 12 months, with benefit in about 50 to 70% and less effect in rigid or severe deformity, and skin bruising as the main side effect.
• Surgery for severe deformity (Haller index above 3.25) with symptoms, cardiopulmonary compression, progression, or psychological distress: the minimally invasive repair (Nuss procedure), with a convex stainless steel bar placed under the sternum by thoracoscopy, is best at 12 to 18 years while the chest is still flexible. Bar stabilisation, and removal after 2 to 3 years.
• Open repair (Ravitch procedure) with cartilage resection and sternal osteotomy for adults, rigid chests and failed repair.
• Pain control: intercostal nerve cryoablation or epidural/paravertebral block, with multimodal analgesia (paracetamol 1 g every 6 hours, ibuprofen 400 mg every 8 hours with food, short course of opioid).
• Associated scoliosis, connective tissue disease and cardiac abnormalities are addressed by the relevant specialists, with psychological support offered.

Complications and prognosis. Surgical complications include bar displacement (2 to 5%), pneumothorax, pleural effusion, pericarditis, infection, bar allergy and wound problems. Recurrence is about 5 to 10%. Most patients have improved exercise capacity and self-image after repair.

Monitoring. Review at 2 weeks, 6 weeks and 3 months after surgery, annually until bar removal, and spirometry before and 6 to 12 months after repair. Annual review in observed cases until growth is complete.

Referral and escalation. Refer to a paediatric or thoracic surgeon with chest wall expertise, cardiology for a murmur or rhythm problem, and genetics for suspected connective tissue disease.