The results from a small study revealed at the recent International Symposium on Endovascular Therapy (ISET), in Miami, FL, have indicated that patients who underwent carotid artery stenting also improved brain function. Dr Rodney Raabe, chief of radiology, Sacred Heart Medical Center, Spokane, WA, and lead author of the study, said many of the showed statistically significant improvement in brain function, such as memory, judgment and reasoning.
"Most people worry about stroke, but they also worry about becoming forgetful and losing their ability to think clearly," said Raabe. "Many patients have returned to a level of function they thought they had lost. That can mean being able to do things for themselves again, including driving to the store to buy milk and living at home independently."
The purpose of this study was to test the hypothesis that carotid stenting with filter protection can prevent the neurocognitive deficit due to emboli causing trauma if they reach the brain. The study used the Acculink stent and the Accunet embolic protection filter (formerly Guidant now Abbott Vascular), which captures microemboli that be dislodged during the procedure.
The study involved very sophisticated neurocognitive measures including IQ, handling of spatial relationships, memory and other executive functions. Patients were tested for memory and executive function five times before and an additional four times after the procedure. The tests include the ability to respond to a command, integrating the command, and providing an answer in return. Functions such as word memory, number memory and assembling sequences were also tested.
For the study, the researchers conducted a two-hour battery of 11 standard neurocognitive tests normally used to assess patients believed to have a degree of dementia such as Alzheimer's disease. The study which involved 37 patients identified cognitive improvements as early as three months and the gains continued when checks were carried out at six and 12-month intervals. A total of 16 patients (43%) showed improved brain function a year after the stent was implanted at the 12-month period.
According to experts the study confirms what they have already observed and they say it supports a fair amount of anecdotal evidence, that using the embolic protection filter did save patients from neurocognitive decline. Therefore, the author concludes that an embolic protection device is beneficial and should be used during carotid stenting procedures. Several studies have looked at brain function after surgery, with mixed results.
"One of the biggest debates in carotid artery disease is whether to treat so-called 'asymptomatic' patients." he added. "Our research suggests we need to rethink the term 'asymptomatic.' Even when people are not at immediate high risk for stroke, if their carotid arteries are clogged, they have reduced blood flow to the brain and that appears to reduce brain function, which is a serious concern."
Originally Raabe wanted to find out if the stenting process would stop the determination of brain function. To his surprise, the brain function in many patients actually got better. It is believed that the stent allows for better blood flow to the brain, and thereby allows for better brain function.
Although research has shown that both surgery and angioplasty with stents can reduce the risk of stroke in asymptomatic patients by half, it has not increased the brain function in all patients. In fact, some patients may have had a decline in cognitive function after the procedure. According to the researchers, patients who undergo the invasive surgery may have a decline in neurological function due to the surgery itself and the anesthesia.
James Benenati, an interventional radiologist at Baptist Cardiac and Vascular Institute, Miami, FL, said the study confirms what he has seen in his own practice. "Many of us anecdotally know this is true. Now it probably is important to do a larger study."
Date: Feb/2007
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