More Biooptics World Articles
Researchers at Case Western Reserve University and University Hospitals Case Medical Center (both in Cleveland, OH) hope to improve treatment and survival rates of ischemic heart disease patients (a disease that blocks coronary arteries, reducing the flow of blood to the heart) by providing doctors an unprecedented look at the stents they place in coronary arteries.
While stent treatment has improved over time, about 5 percent of stents fail in the first year following implant and an additional 1 percent every additional year due to recurrent narrowing of the artery or the formation of blood clots at the site, according to Hiram G. Bezerra, MD, an assistant professor of cardiology at Case Western Reserve's School of Medicine and expert in intravascular optical coherence tomography (OCT). OCT is an imaging technique that takes reflections of an infrared (IR) laser in the artery measured at various depths to produce a three-dimensional (3D) image. The technology has 10 times the resolution of the analogous ultrasound-based technology, called intravascular ultrasound (IVUS).
The research team is looking at using intravascular OCT to help doctors determine whether a stent is restoring circulation as designed, if more stents are needed to seal off a problem area, or whether a stent has failed or become a trouble spot. OCT will take as many as 500 images of each stent; David Wilson, professor of biomedical engineering and radiology, is developing software to quantitatively analyze every detail captured within minutes. Currently, such analysis takes a trained doctor eight to 15 hours; the software Wilson is developing will also eliminate the variability of manual analysis, he explains.
Andrew Rollins, a professor of biomedical engineering and also an expert in OCT, has been tailoring OCT for multiple applications. His understanding of the OCT imaging process helps the team tailor software to recognize plaques in the heart's arteries and identify those likely to ruptureâthe most common cause of heart attacks and the areas targeted for stents.
The rapid return of information would allow cardiologists implanting stents to determine if more stents are needed to seal off plaques likely to rupture, or to optimize the stent deployment âfor example, making the devices wider to improve blood flow during the procedure.
If a stented patient complains of problems or doesn't improve, the doctor would be able to reexamine during a follow-up visit to see if the stent scaffold is covered with new tissue, as designed. The findings may be used to guide therapy, such as prescribing medication to prevent blood clotting that can occur at the uncovered site.
In addition to clinical practice, the technology will also be used to guide research and development of new stent designs. Stents can have different architectures and be made of metal or materials that are absorbed by the body. They can be coated to activate cell coverage and hold and release a variety of drugs.
The research team has received a $1.7 million grant from the National Institutes of Health's National Heart, Lung and Blood Institute to fund their work.
Follow us on Twitter, 'like' us on Facebook, and join our group on LinkedIn
Subscribe now to BioOptics World magazine; it's free!