[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Blood vessels](https://durgical.com/en/general-pathology/areas/vessels/) › Pathology after angioplasty, stents and grafts

# Pathology after angioplasty, stents and grafts

- Process

Opening or replacing a narrowed artery injures it again; clots and new scar tissue can close it.

Updated Nov 12, 2026

## Key points

- Angioplasty fractures the plaque and stretches the media, causing dissection and thrombosis risk.
- In-stent restenosis: neointimal hyperplasia of smooth-muscle cells and matrix, typically within months.
- Drug-eluting stents reduce restenosis; dual antiplatelet therapy protects against stent thrombosis while the endothelium regrows.
- Saphenous vein grafts: intimal thickening, then accelerated atherosclerosis; many are narrowed or occluded within about a decade.
- Internal mammary (thoracic) artery grafts remain open far longer than vein grafts.

## What it is

Balloon angioplasty and stenting open narrowed arteries by breaking and stretching the plaque, which injures the wall. Early failure comes from thrombosis on the injured surface or the stent; later failure from in-stent restenosis, a proliferation of smooth-muscle cells and matrix (neointimal hyperplasia). Drug-eluting stents release antiproliferative agents that reduce restenosis but delay endothelial coverage, so late stent thrombosis is a concern. Vein grafts develop intimal thickening and later atherosclerosis; arterial grafts (internal mammary artery) last longer.

## Structure

- In-stent restenosis: stent struts surrounded by a thick layer of smooth-muscle cells in a proteoglycan-rich matrix, covered by endothelium.
- Vein graft: concentric intimal fibromuscular thickening; later atheromas with necrotic cores.

## Step by step

- The balloon or stent expands the artery, cracking the plaque and denuding the endothelium.
- Platelets and fibrin deposit on the injured surface and on stent struts.
- Inflammation and growth factors activate medial smooth-muscle cells.
- Smooth-muscle cells migrate, proliferate and make matrix inside the stent.
- The new endothelium covers the struts; excessive neointima narrows the lumen again.

## Failure modes after revascularisation

| Problem | When | Mechanism |
| --- | --- | --- |
| Acute occlusion | Hours to days | Dissection or thrombosis on the injured wall |
| Stent thrombosis | Early, or late with drug-eluting stents | Exposed struts without endothelium |
| In-stent restenosis | Months | Neointimal hyperplasia (smooth-muscle cells and matrix) |
| Vein graft disease | Years | Intimal thickening, then atherosclerosis in the graft |

## Clinical notes

- Recurrent angina months after stenting suggests restenosis; sudden infarction suggests stent thrombosis.

## Memory aid

Fix the pipe and it heals too well: clot in days, scar in months, plaque again in years.

## Test yourself

Think of the answer, then tap the question to see it.

## What tissue causes in-stent restenosis?

Neointimal hyperplasia: proliferating smooth-muscle cells and extracellular matrix inside the stent.

## Why do drug-eluting stents raise concern about late thrombosis?

The antiproliferative drug slows endothelial coverage of the struts, leaving thrombogenic metal exposed longer.

## Which bypass conduit stays open longest?

The internal mammary (internal thoracic) artery, compared with saphenous vein grafts.

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## Connections

## Related 5

- [Vessel wall response to injury](https://durgical.com/en/general-pathology/vessel-wall-response-to-injury/)
- [Consequences of atherosclerosis](https://durgical.com/en/general-pathology/consequences-of-atherosclerosis/)
- [Granulation tissue and scar formation](https://durgical.com/en/general-pathology/granulation-tissue-and-scar-formation/)
- [Arterial vs venous thrombi; mural thrombi and lines of Zahn](https://durgical.com/en/general-pathology/arterial-vs-venous-thrombi-mural-thrombi-and-lines-of-zahn/)
- [Heart transplantation and cardiac devices](https://durgical.com/en/general-pathology/heart-transplantation-and-cardiac-devices/)

## Related conditions 4

- [Stable angina](https://durgical.com/en/conditions/stable-angina/)
- [Myocardial Infarction (Heart Attack)](https://durgical.com/en/conditions/myocardial-infarction/)
- [Peripheral artery disease](https://durgical.com/en/conditions/peripheral-artery-disease/)
- [Carotid artery stenosis](https://durgical.com/en/conditions/carotid-artery-stenosis/)

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Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.

Sources: [Angioplasty and stent placement - heart: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/007473.htm) (MedlinePlus, US National Library of Medicine, 2025).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/general-pathology/pathology-after-angioplasty-stents-and-grafts/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/pathology-after-angioplasty-stents-and-grafts/