A 9-year-old boy evaluated for headache is found to have hypertension in the upper limbs (148/90 mmHg) while femoral pulses are weak and delayed. A short systolic murmur is heard over the left interscapular area. Chest X-ray shows bilateral inferior rib notching. The underlying anatomy responsible for the rib notching is:

• A Enlarged bronchial arteries
• B Erosion by dilated azygos vein
• C Internal mammary artery aneurysms
• D Dilated intercostal arteries acting as collaterals ✓

Explanation

In coarctation distal to the origin of the left subclavian artery, blood reaches the lower body through enlarged posterior intercostal collaterals arising from the subclavian arteries. Their tortuosity erodes the inferior surface of the ribs, producing the classic notched appearance. Rib notching typically appears only after several years of life, usually beyond 5 years of age, because collateral vessels take time to enlarge. Bronchial arteries supply lung tissue, not the chest wall.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.