An extensive well developed collateral system is noted in the anterolateral chest wall, thorax, abdomen and in the muscular plane along the back.
Angiographic examination of the aorta shows a focal area of narrowing and constriction with dilatation of aorta proximal and distal to the narrowed segment.
Collateral pathways have developed through the internal mammary, long thoracic, intercostal, spinal, vertebral and superior epigastric arteries.