Pectus Carinatum

Pectus carinatum (pigeon chest) is a congenital outward protrusion of the sternum and costal cartilages. It is about one fifth as common as pectus excavatum, found in about 1 in 1500 people, with a male predominance (4 to 1) and a family history in about a quarter.

It usually appears or progresses in early adolescence, with growth, at 11 to 14 years, and rarely at birth. Associated conditions are scoliosis, Marfan syndrome, Noonan syndrome, homocystinuria, osteogenesis imperfecta, congenital heart disease and Poland syndrome. Severe asthma and rickets can produce a similar deformity.

Pathophysiology. Excessive growth of the costal cartilages pushes the sternum outward. In the chondrogladiolar type (most common), the body of the sternum protrudes, and in the chondromanubrial type (Currarino-Silverman), the upper sternum and manubrium protrude, with a sternal angle abnormality and a risk of cardiac anomaly. Asymmetric forms rotate the sternum.

A visible chest protrusion, with or without lateral depressions of the ribs (Harrison sulcus) and asymmetry. Most are free of symptoms. Some have exertional dyspnoea or chest pain, tenderness over the protruding cartilage and reduced exercise tolerance. Psychological distress and avoidance of sports are frequent.

• Clinical examination of the type, flexibility (compressibility with manual pressure) and associated spinal, cardiac and connective tissue features.
• Chest CT or MRI to assess deformity, cardiac anatomy, and the chest index. Imaging is not needed for mild flexible cases.
• Spirometry: usually normal, sometimes mildly obstructive or restrictive.
• Echocardiography when there is a murmur, family history, or manubrial type, since congenital heart disease is more frequent.
• Genetic evaluation for Marfan syndrome (aortic root measurement and ophthalmic assessment) when stature, arm span or other features suggest it.

• Observation for mild, asymptomatic cases, with exercise and posture exercises, and review through the growth years.
• Dynamic compression bracing for flexible deformity in adolescents (best at 11 to 17 years): custom orthosis worn for 14 to 23 hours daily for 6 to 12 months, then at night for another 6 to 12 months for maintenance. Success is 70 to 90% with good adherence, and the main adverse effects are skin irritation and discomfort. Bracing is less effective in rigid, adult or manubrial forms.
• Surgery for severe, rigid, symptomatic, failed bracing or adult deformity: the open Ravitch operation (resection of deformed cartilage, sternal osteotomy and fixation), or the minimally invasive repair of pectus carinatum (Abramson procedure) with a bar placed over the sternum for compression, which gives results with less dissection. Bar removal after 1 to 2 years.
• Analgesia after surgery with multimodal drugs (paracetamol 1 g every 6 hours, ibuprofen 400 mg every 8 hours with food) and regional block.
• Associated problems: scoliosis, connective tissue disease, heart disease, and psychological distress needing counselling.

Complications and prognosis. Recurrence after bracing is 5 to 15%, usually because of poor adherence, and after surgery about 5%. Other complications are seroma, infection, pneumothorax and bar displacement. Cosmetic outcomes are usually good.

Monitoring. Review every 3 months during bracing, adherence and skin checks, and at 6 and 12 months after bracing is stopped. After surgery, review at 2 weeks, 6 weeks, 3 months, and bar removal at 1 to 2 years.

Referral and escalation. Refer to a paediatric surgeon or thoracic surgeon with chest wall expertise, and to cardiology or genetics if features suggest associated disease.