October 9, 2009

Pectus Excavatum

An axial CT image shows a measurement of Haller index (A = transverse diameter, B = anteroposterior diameter of the inner chest wall), which is approximately 3.4 indicating severe pectus excavatum.


Facts: Pectus Excavatum
  • Congenital chest wall deformity "caved-in" or concave appearance in the anterior chest wall
  • Most common type of congenital chest wall deformity (90% of all), followed by pectus carinatum (approximately 5%)
  • Most cases are diagnosed within the first year of life
  • Worsening during rapid bone growth (early teenage)

Diagnosis
  • Easy to make on a clinical ground
  • Radiography and chest CT performed to determine the need of surgery, and for surgical planning
  • Haller index is used to grade the severity (Haller index = transverse chest diameter divided by anteroposterior diameter)
  • Haller index > 3.2 correlates with severe deformity that requires surgery
  • Two morphologic classifications of pectus excavatum: 1) symmetric (center of the sternum is the same as the center of depression 2) asymmetric (center of the depression is off to one side i.e. not at the same location as the center of the sternum). Chest CT is best used to show the morphology and for surgical planning
References:
1. Park HJ, Lee SY, Lee CS, et al. The Nuss procedure for pectus excavatum: evolution of techniques and early results on 322 patients. Ann Thorac Surg 2004;77:289-295.
2. Hebra A. Pectus excavatum. In: E-medicine, updated Sep 21, 2009.

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