Restenosis is the recurrence of stenosis, a narrowing of a blood vessel, leading to restricted blood flow. Restenosis usually pertains to an artery or other large blood vessel that has become narrowed, received treatment to clear the blockage and subsequently become renarrowed. This is usually restenosis of an artery, or other blood vessel, or possibly a vessel within an organ.

Restenosis is a common adverse event of endovascular procedures. Procedures frequently used to treat the vascular damage from atherosclerosis and related narrowing and renarrowing (restenosis) of blood vessels include vascular surgery, cardiac surgery, and angioplasty.

When a stent is used and restenosis occurs, this is called in-stent restenosis or ISR. If it occurs following balloon angioplasty, this is called post-angioplasty restenosis or PARS. The diagnostic threshold for restenosis in both ISR or PARS is ≥50% stenosis.

If restenosis occurs after a procedure, follow-up imaging is not the only way to initially detect compromised blood flow. Symptoms may also suggest or signal restenosis, but this should be confirmed by imaging. 

DIAGNOSIS OF RESTENOSIS

It includes the following:

• Coronary angiogram.  Dye is injected into the artery to reveal blockages and show how well the blood flows on an X-ray.

• Intravascular ultrasound. Sound waves are emitted from a catheter to create an image of the inside of the artery.
• Optical coherence tomography. Light waves are emitted from a catheter to create high-resolution images of the inside of the artery.

TREATMENT OF RESTENOSIS

Restenosis that doesn’t cause symptoms usually doesn’t need any treatment.When symptoms do appear, they usually gradually worsen, so there’s time to treat the restenosis before the artery completely closes and causes a heart attack.Restenosis in an artery without a stent is usually treated with balloon angioplasty and DES placement.ISR is usually treated with the insertion of another stent (usually a DES) or angioplasty using a balloon. The balloon is coated with medication used on a DES to inhibit tissue growth.If restenosis continues to happen, your doctor may consider CABG  to avoid placing multiple stents.IST is almost always an emergency.Upto 40% of people who have an IST don’t survive it. Based on the symptoms, treatment for unstable angina or a heart attack is started. Usually PCI is performed to try to reopen the artery as soon as possible and minimize heart damage.