restenosis after angioplasty is primarily due to which processes?

• A. Intima hyperplasia, elastic recoil, or thrombosis
• B. Vasospasm alone
• C. Infection of the vascular wall
• D. Neovascularization only

Answer: (A)

Restenosis after angioplasty mainly comes from three intertwined processes: intimal hyperplasia, elastic recoil, and thrombosis. When the vessel is injured by the catheter or balloon, smooth muscle cells from the media migrate into the intima and multiply, laying down extracellular matrix. This neointimal growth thickens the vessel wall and narrows the lumen over weeks to months. Elastic recoil is the vessel’s immediate tendency to snap back toward its pre-dilated size after the balloon is deflated, which can reduce lumen diameter right away if the vessel or stent doesn’t stay fully expanded. Thrombosis at the site can form a clot that narrows the lumen and may organize over time into scar tissue that contributes to late narrowing.

Vasospasm tends to be transient and doesn’t usually account for long-term restenosis. Infection is not a primary driver of restenosis, and neovascularization alone doesn’t explain the process, since restenosis is driven by neointimal thickening from smooth muscle proliferation and matrix deposition, with recoil and thrombus as important contributors.