Restenosis Prevention

Stents have dramatically reduced the incidence of stenosis following percutaneous angioplasty. However, they are also known to restenose within months. Prevention of restenosis therefore depends on several factors:

  • Accurate stent placement and expansion, which avoids the occurrence of empty spaces for scar buildup
  • Use of targeted treatments to reduce neointimal hyperplasia and restenosis, which include:
    • Drug-eluting stents
    • Perivascular delivery which delivers the drug into the space around the artery
    • Delivery catheters
    • Antibody or peptide-linked drugs
    • Gene-based therapies
    • Cell-based therapies
    • Nanoparticle-based drug delivery
  • Lifestyle modifications as advised by the cardiologist, including regular exercise, lowering of blood pressure, quitting smoking and cutting down to one drink of alcohol, and a low-fat diet.
  • Use of appropriate medication to prevent platelet clots from forming

There are several categories of drugs for restenosis:

  • Drugs which inhibit coagulation, such as anticoagulants, antithrombotic agents and antiplatelet agents like clopidogrel and heparin
  • Anti-inflammatory agents such as dexamethasone and tranilast
  • Drugs which inhibit proliferation and oppose growth factors, such as ACE inhibitors, trapidil, tyrphostin
  • Cytostatic drugs which inhibit cell growth, like paclitaxel and rapamycin
  • Lipid-lowering agents such as statins
  • Antioxidants such as probucol or resveratrol

Vascular brachytherapy

Vascular brachytherapy is another technique used to prevent or treat a restenotic lesion. Here short-range ionizing therapy is used to inhibit neointimal hyperplasia, so as to prevent shrinkage of the arterial lumen after angioplasty. The radiation produces:

  • Inhibition of smooth muscle cell proliferation
  • Increased number of cells that enter the apoptosis pathway
  • Less fibrosis
  • Less negative remodeling, or healing which results in a shrunken lumen

Characteristic changes in irradiated vessels include:

  • Persistent absence of endothelium over the irradiated part of the vessel
  • Fibrin deposition over the bare area
  • Inflammatory cell infiltration of the vessel wall

Vascular brachytherapy can be used alone or following angioplasty of a restenotic lesion. This is performed through a special catheter placed for 10 minutes inside the blocked segment, and containing a source of short-term radiation.

References

Further Reading

Last Updated: May 25, 2015

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