Restenosis

Restenosis usually pertains to an artery or other large blood vessel that has become narrowed, received treatment to clear the blockage, and subsequently become re-narrowed.

[3] If restenosis occurs after a procedure, follow-up imaging is not the only way to initially detect compromised blood flow.

For instance, a coronary stent patient who develops restenosis may experience recurrent chest pain (angina) or have a minor or major heart attack (myocardial infarction), though they may not report it.

The balloon inserted into the narrowing 'smashes' the cholesterol plaques (atherosclerosis) against the artery walls, thus widening the size of the lumen and increasing blood flow.

[citation needed] Damage to the blood vessel wall by angioplasty triggers a physiological response that can be divided into two stages.

[citation needed] The second stage tends to occur 3–6 months after surgery and is the result of the proliferation of cells in the media, a smooth muscle wall in the vessel.

It measures either the percent (relative) or absolute change in minimum luminal diameter (MLD) over the months following a vascular procedure, such as the implantation of a stent graft.

[citation needed] However late loss is only part of the terminology in describing the outcomes of vascular interventions.

However, over time, the body's inflammatory immune response (described below in the "Causes" section) reacts to the stent graft via smooth muscle proliferation, etc., which pushes the stent graft back, narrowing the vessel and losing at least a percentage of what was previously gained, or late loss.

[citation needed] In the first stage of restenosis, administering anti-platelet drugs (called IIb/IIIa inhibitors) immediately after surgery greatly reduces the chance of a thrombosis occurring.

Additionally, DCB treatment does not leave an implant in the body and is designed for faster drug delivery.

The radiation kills cells and inhibits tissue growth (similar to a patient undergoing cancer therapy).

[18] A 2010 study in India comparing coronary drug-eluting stents (DES) with coronary bare-metal stents (BMS) reported that restenosis developed in 23.1% of DES patients vs 48.8% in BMS patients, and female sex was found to be a statistically significant risk factor for developing restenosis.

[21] A 2009 study compared bare nitinol stents with percutaneous transluminal angioplasty (PTA) in subsartorial artery disease.

The phenomenon of vessel restenosis, an immune response to damaged tissue, is known to be a common adverse event and the Achilles heel of angioplasty and stenting. Reducing restenosis is one of the highest priorities in research and the development of new endovascular technologies. Restenosis rates of drug-eluting stents appear to be significantly lower than bare-metal stents , and research is underway to determine if drug-coated balloons also improve restenosis outcomes.
Conceptual schematic illustrating effectiveness of endovascular interventions on lumen diameter to improve blood flow as represented by acute gain, late loss (restenosis), and net gain.