February 1, 2012
Re-Blockage Rates Low In Both Stented And Surgically-Opened Arteries
Opening blocked neck arteries with a metal stent or surgery were equally durable, in research presented at the American Stroke Association's International Stroke Conference 2012.
Two years after the procedures, less than 7 percent of patients had developed repeat blockages (restenosis), researchers said."Unlike bare metal stents placed in coronary arteries, where re-blockage occurs about 20 percent of the time, we found the re-blockage rates in the carotid artery were quite small," said Brajesh K. Lal, M.D., lead author of this analysis and associate professor of vascular surgery at the University of Maryland School of Medicine in Baltimore. "Patients and physicians can be reassured that both procedures are durable and that re-blockage rates are equivalent, so they can use different criteria to determine which procedure is right for a patient."
The study is the largest to look at restenosis rates after either procedure.
The study participants – part of the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) – had partial blockages in a neck artery. Symptomatic patients had experienced a non-disabling stroke or transient ischemic attack (mini-stroke) because of the blockage, while asymptomatic patients had not.
Previously, this head-to-head comparison of the two procedures showed no difference in the combined rates of stroke, heart attack or death between patients undergoing surgical removal of a blockage (carotid endarterectomy) or stenting.
About 10 percent of strokes are caused by blockages in the neck arteries, which supply blood to the brain. Revascularization procedures preserve blood flow and lower the risk of stroke.
In the current study, 1,086 patients received stenting and 1,105 endarterectomy. All were assessed at one, six, 12 and 24 months after the procedure with an ultrasound to identify those who had developed a 70 percent or greater blockage in the treated section.
After two years, the researchers found:
Identical rates of restenosis (5.8 percent) after stenting and endarterectomy.
Complete blockage (occlusion) in 0.3 percent after stenting and 0.5 percent after endarterectomy.
Combined restenosis/occlusion in 6 percent after stenting and 6.3 percent after endarterectomy.
Twenty stent patients and 23 endarterectomy patients had undergone a second procedure to open a re-blocked carotid.
Rates of restenosis were about double in women and patients with diabetes and abnormal lipid levels.
Stroke rates were 4 times higher in patients who developed a restenosis compared to those that did not develop a restenosis during follow-up.
"These may be groups we need to focus more on by monitoring them closely and aggressively controlling risk factors after the procedures," said Lal, who is also chief of vascular surgery at the Baltimore VA Medical Center in Maryland.
Physicians from different specialties perform revascularization procedures. In the study, results didn't differ by specialty.
"CREST was unique in having a built-in training and credentialing process that mandated participating physicians perform 1,500 revascularization procedures before randomizing any patients," Lal said. "These results provide hard data for the FDA and professional societies to use as they recommend a particular type or extent of training for performing these procedures." Monitoring of CREST participants will continue through 10 years.
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