However, to prevent development of blood clots, doctors have to give patients high doses of blood thinners, which are associated with serious complications of their own. To answer that question, he and Emory cardiologist Spencer King worked with hematologists Stephen Hanson and Laurence Harker to develop a drug-impregnated sheath to be wrapped around the stent. Release of tiny amounts of the anticoagulant in the area around the stent results in a high local concentration of the blood thinner and a low systemic concentration. The drug supply is temporary, intended only to get the patient through the critical first week after angioplasty. The group capitalized on the dynamics of blood flow through the vessel.
Flow is slowest against the arterial wall and fastest in the middle of the stream.
Dr. Hanson and the other researchers developed a catheter that can be positioned against the arterial wall, a little upstream of the area that needs to be treated. Tiny holes in the catheter allow the drug to seep out, where it is caught in the slower-moving part of the bloodstream and carried to the angioplasty site, where it reaches its highest concentration and can do the most good. The researchers have a patent pending on this device and have already licensed its development to Minneapolis-based Interventional Innovations Corporation. A third technology currently being developed to prevent restenosis uses low-dose radiation to inhibit formation of scar tissue. Emory investigators Ron Waksman, Ian Crocker, Keith Robinson, and Spencer King have collaborated to develop a technique to deliver low-dose radiation to the angioplasty site.