Description

Pectus carinatum or pigeon breast (pigeon chest) or pyramidal chest or horseshoe chest is a chest wall deformity characterised by an anterior (outward) projection of the sternum and adjacent lateral cartilage. The chondrogladiolar subtype is the most common and involves the protrusion of the sternal body and the xiphoid process. The chondromanubrial subtype involves the protrusion of the upper part of the sternum, i.e. the sternal grip, and presents as a single deformity or in combination with a depression of the xiphoid process. It is the second most common congenital deformity of the chest wall after pectus excavatum and occurs most frequently in the male sex. It usually first presents in early adolescence and the deformity is maximized during adolescent skeletal development.

Carinoid sternum is mainly an aesthetic problem and is rarely accompanied by cardiorespiratory symptoms. It usually coexists with scoliosis. The main cause of carinoid sternum is unknown, but about 25% of patients have a positive family history of chest wall deformities and it is usually associated with other musculoskeletal or connective tissue diseases such as Marfan syndrome, Noonan syndrome (70-95%).

Epidemiology

Carinoid sternum is more common in males (male/female 4:1). The prevalence rate of carinoid sternum is 0.6-0.7% in children aged 7-14 years.

Reason

The cause of congenital carinoid sternum is unknown, but in 25% of cases there is a genetic predisposition. Acquired carinoid sterno is usually due to postoperative complications after thoracic surgery, such as after surgical repair of scaphoid sternum.

Pathogenesis

The pathogenesis of carinoid sternum may be associated with either overgrowth of the lateral cartilage or with the deepening of the lateral rib arches in the chondrogladiolar subtype of the presentation. Whereas in the chondromanubrial subtype the pathogenesis may be associated with abnormal ossification of the sternum (premature fusion and coalescence) resulting in protrusion of the sternal grip and upper lateral cartilage.

Clinical picture

Symptoms usually appear during the sudden physical growth in adolescence. The most common are:

• Concern for the aesthetics of the body's appearance
• Discomfort and/or pain when lying in a prone position
• Musculoskeletal chest pain
• Epigastralgia
• Palpitations
• Tachypnea, shortness of breath, wheezing
• Difficulty in applying the bra in teenage girls
• Psychosocial difficulties

Clinical examination

Chest

Carrying out a medical assessment:

• the degree of protrusion of the sternum and lateral cartilage
• the symmetry or asymmetry of the deformity in the two halves
• the twisting of the sternum
• the eudibility of the thoracic cage
• of coexistence Pectus excavatum
• the coexistence of syndromes (Marfan, Noonan)

Heart

Cardiac assessment including identification of congenital heart disease.

Respiratory

Check for wheezing.

Musculoskeletal

Check for the presence of scoliosis (12-24%).

Diagnosis

The diagnosis is mainly based on clinical examination and when clinically severe dysmorphia is diagnosed, then it is decided to perform further imaging tests, detailed cardiological and respiratory examination in order to accurately determine the degree of dysmorphia and its influence on cardiorespiratory function.

Diagnostic tests

• Chest CT
  
  • assessment of the severity of the deformity by calculating the Haller index (transverse internal diameter of the thoracic cage / shortest sternoclavicular depth), where Haller index 1.2-2.0 means a severe degree of deformity
  • assessment of the symmetry of the thoracic cage
  • assessment of the coexistence of other malformations
    • Pectus excavatum
    • sternal cleft (bifid sternum)
    • asphyxial thoracic dystrophy (Jeune syndrome),
    • Poland syndrome
• Spirometry
  
  • assessment of respiratory function
• Hypercardiogram
  
  • assessment for coexisting heart disease
• MRI of the chest - heart can replace CT and echocardiography (and at the same time avoid radiation exposure)
• Genetic testing
  
  • assessment of the existence of syndromes on clinical evidence

 Treatment

Treatment of the carinoid sternum is indicated for symptomatic patients or for aesthetic reasons.

Non-surgical treatment of carinoid sternum

Non-surgical treatment with the application of an orthotic compression band is the first treatment option. It requires the presence of a benign chest wall and is most effective in 10-15 year olds. There are many protocols involving daily time (14-24 hours/day) and total time of application (6-24 months) with very good results (up to 88.4%). The common complications are skin rash, pain and hematoma.

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Surgical treatment of carinoid sternum

Surgical repair is attempted when non-surgical treatment fails. The surgical modern repair techniques are two:

• Intervention by Nuss
  
  • It is essentially two operations, one for the thoracoscopic placement of a metal bar that raises the sternum to its normal position and a second operation after 2-3 years to remove the bar.
• Ravitch intervention
  
  • This is a single open surgery in which all the lateral cartilage causing the deformity is removed. It is indicated for all deformities, even asymmetrical or more complex ones, and for people who do not want two surgeries or the implantation of a metal bar.

American Society of Pediatric Surgery Guidelines for the treatment of carinoid sternum