A 22-year-old man presents with hypertension in the upper limbs and radiofemoral delay. Chest radiograph shows bilateral inferior rib notching. Which vessels mediate this collateral circulation?

• A Internal thoracic and musculophrenic arteries
• B Posterior intercostal arteries via the subclavian and descending thoracic aorta ✓
• C Superior epigastric and inferior epigastric arteries alone
• D Bronchial arteries anastomosing with pulmonary arteries

Explanation

In preductal or juxtaductal coarctation, blood bypasses the narrowing via the subclavian artery, internal thoracic artery, anterior intercostal arteries, and dilated posterior intercostal arteries arising from the descending aorta below the obstruction. Enlarged posterior intercostal arteries erode the inferior borders of ribs, producing the classic notching of ribs 3 to 8. Epigastric collaterals exist but do not cause rib notching.

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.