A 55-year-old with occlusive disease of the left superficial femoral artery (SFA) causing claudication undergoes percutaneous transluminal angioplasty (PTA). Post-angioplasty, the vessel shows a dissection with flow limitation on DSA (digital subtraction angiography). A bare-metal stent is deployed. The primary mechanism by which balloon angioplasty achieves luminal gain is:
- A Compression and dissolution of the atheromatous plaque
- B Thermal ablation of the plaque by the balloon
- C Stretching and cracking of the atherosclerotic plaque with outward remodelling of the vessel wall, NOT removal of plaque ✓
- D Mechanical removal of plaque from the lumen
Correct answer: C. Stretching and cracking of the atherosclerotic plaque with outward remodelling of the vessel wall, NOT removal of plaque
Explanation
Percutaneous transluminal angioplasty (PTA) achieves luminal enlargement primarily by controlled fracture and cracking of the atherosclerotic plaque with outward displacement (axial stretching) and vessel wall remodelling. Plaque is NOT removed, dissolved, or thermally ablated — it is compressed and redistributed circumferentially, and the outer adventitia is stretched. This mechanism explains the risk of arterial dissection (a plaque fracture plane extending into the intima/media), which is then treated with stenting if flow-limiting.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.