Sixty million Americans have some form of cardiovascular disease, ranging from congenital heart defects to high blood pressure to hardening of the arteries. For most, coronary artery disease means that the arteries in the heart have become narrowed or blocked by fatty deposits called plaques. This condition is treated in a variety of ways including cholesterol-reducing medications, coronary angioplasty, and coronary artery bypass surgery. Some have a stent—a metal, mesh tube—placed in the coronary artery and expanded to provide support to the diseased artery. The device helps maintain blood flow in previously blocked cardiac arteries. Restenosis, or new blockage, may develop in 15 to 20 percent of patients who undergo stent placement. Now, an exciting new procedure called vascular brachytherapy can prevent or reduce the occurrence of restenosis.

What does the new procedure involve?

Vascular brachytherapy, also known as intravascular brachytherapy or endovascular brachytherapy, is a revolutionary new procedure that uses radiation to reduce the incidence of renarrowing (restenosis) of coronary arteries. Tiny amounts of radiation are delivered to unblock the stent and help it remain open for long periods. Using radiation therapy inside an artery reduces the likelihood of needing further angioplasties or coronary bypass surgery. Beta radiation is delivered in less than five minutes and with minimal radiation exposure to the patient's healthy tissues.

Which specialists perform this procedure?

A cardiologist, a radiation oncologist and a physicist function as a team to ensure that just the right amount of dosage is delivered to precisely the spot where it is needed. Total procedure time is usually about 45 minutes. There are no significant side effects, and the patient generally returns home after an overnight stay.How does the radiation delivery system work? First, a catheter is placed in the artery with markers at the site of blockage. Connected to the catheter inside the coronary artery, a tiny delivery device containing radioactive pellets is introduced into the catheter. Administering carefully calculated doses of radiation at the site of stent blockage takes less than five minutes. After the treatment, the patient is not radioactive, as the delivery source and radiation are removed.

How effective is the treatment?

"We have found the procedure to be more than 90 percent effective for stent patients who experience reblockage," says John Muir Medical Center, Concord Campus cardiologist Gus Argenal, M.D. "Studies in thousands of cases around the world have shown five years of persistent efficacy. In giving radiation to the small subgroup of patients demonstrating the greatest tendency for stent reblockage, a double-blinded study showed reduced restenosis of 60 to 70 percent in that high-risk group. No other intervention has prevented that problem as effectively."

Is every stent patient a candidate for vascular brachytherapy?

"At this time, vascular brachytherapy is approved and used only for patients with coronary artery disease who have had a renarrowed artery at the site where a stent is already in place," explains John Muir Medical Center, Walnut Creek Campus cardiologist Christopher Wulff, M.D. "In the future, we may use the technique when a stent is first installed to help prevent additional adverse cardiac complications." Last year, 587 stent placement procedures were performed at John Muir Health. More than 50 vascular brachytherapy procedures have been done at the two hospitals since January. John Muir Health physicians were the first in the East Bay to use the Beta-Cath™delivery system, recently approved by the FDA.

What are other potential applications for this device and procedure?

"We are just beginning to see the full potential of vascular brachytherapy in the area of interventional cardiology," Dr. Wulff points out. "This modality is also stimulating further research to treat other medical problems."Dr. Argenal adds, "In the future, we hope to use vascular brachytherapy in conjunction with original stent placement or in small vessels during angioplasty."