Pectus excavatum
Updates to Article Attributes
Pectus excavatum (or funnel chest) is a congenital chest wall deformity characterised by concave depression of the sternum, resulting in cosmetic and radiographic alterations.
Epidemiology
It is the most common chest wall deformity, accounting for approximately 90%, and occurs in up to 1 in 300-1000 births 1, 4 and is more frequently seen males (M:F = 3 : 1). The opposite deformity is known as pectus carinatum (pigeon chest).
Pathology
Associations
Although most are sporadic it can be seen in association with
- Marfan syndrome
- Noonan syndrome
- Ehlers Danlos syndrome
- neurofibromatosis type I
- myotonic dystrophy
- foetal alcohol syndrome
- homocystinuria
- osteogenesis imperfecta
- congenital scoliosis
- Poland syndrome 6
Clinical presentation
Although usually objectively asymptomatic, many patients report perceived inability to sustain physical activity. This is often associated with significant body-image issues which can have serious implications for affected children 4. Other than the obvious cosmetic and psychological issues, pectus excavatum is also occasionally associated with:
- mitral valve prolapse
- restrictive pulmonary function test abnormalities
- cardiac functional abnormalities
Radiographic features
Plain film
Characteristically demonstrates :
- blurring of right heart border (PA or AP film)
- increased density of the inferomedial lung zone 5
- horizontal posterior ribs
- vertical anterior ribs (heart shaped)
- displacement of heart towards the left
- obliteration of the descending aortic interface 5
CT
The diagnosis is obvious on CT with the degree of deformity and mediastinal shift often dramatic.
The Haller index (maximal transverse diameter/ narrowest AP length of chest) is used assess severity. Normal Haller index is 2.5. Significant pectus excavatum has an index greater than 3.25.
Treatment and prognosis
Although historically most cases were not treated, and early research suggested that even in extreme cases repair does not offer significant improvement in respiratory function tests 2 more recently symptomatic improvement in ventilation and perfusion scans, as well as numerous other symptoms has been described 3,7-8. Importantly, and contrary to earlier beliefs, pectus deformities often persist into adulthood and symptoms may become more pronounced 8.
In addition so symptoms, the negative effects on body image and normal psychological development should also not be underestimated 4.
Surgical options include metal bar insertion, rib osteotomies, disconnection of the sternum from costal cartilages and even reversal of the sternum 2. The Nuss procedure is a minimally invasive procedure where a concave bar is inserted substernally. It has largely replaced the Ravitch procedure which was significantly more invasive.
Differential diagnosis
For the unwary, pectus excavatum can be troublesome on frontal chest radiographs. Differential includes :
- right middle lobe consolidation/atelectasis
- left para-aortic soft tissue density
- lung or paravertebral mass
- atelectasis / consolidation of the medial segment of the left lower lobe
- mediastinal mass due to deformation of the cardiomediastinal contour
The diagnosis is obvious on lateral projection, and of course cross sectional imaging.
-<li><a href="/articles/marfan-s-syndrome">Marfan syndrome</a></li>- +<li><a title="Marfan syndrome" href="/articles/marfan-syndrome">Marfan syndrome</a></li>
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