New Results Show Improved Brain Function Retained A Year After Minimally Invasive Stroke Treatment
May 16, 2017
New data shows that a year
after undergoing carotid angioplasty and stenting, a minimally invasive
treatment to prevent stroke, nearly half of patients (43 percent) showed
statistically significant improvement in brain function, such as memory,
judgement and reasoning. Those are the findings of a groundbreaking study
being presented at the International Symposium on Endovascular Therapy
(ISET).
"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," said Rodney Raabe, M.D., chief of radiology at Sacred Heart
Medical Center, Spokane, Wash. "As they get older, most people worry about
stroke, but they also worry about becoming forgetful and losing their
ability to think clearly."
In the right patient, this treatment appears to be able to improve
brain functions of memory and the ability to reason, both of which are
important for independent living. In the study, researchers performed a
two-hour battery of 11 standard neurocognitive tests commonly used to
assess patients believed to have a dementing process, such as Alzheimer's
disease. Tests included functions such as having patients remember a list
of words, think abstractly, repeat digits in sequential and reverse
sequential order, generate lists based on cues, and complete puzzles of
alternating sequences.
In the study, 16 (43 percent) of 37 patients showed significantly
improved neurocognitive function one year after the carotid angioplasty and
stenting procedure. Improvement was seen at three months and continued
through the six and twelve month assessment points. Of the remaining
patients, neurocognitive function remained stable in 20 (54 percent) and
declined in one (3 percent) at one year.
"One of the biggest debates in carotid artery disease is whether to
treat so-called 'asymptomatic' patients: those who have clogged carotid
arteries but don't have early warnings of stroke, such as transient
ischemic attacks (TIAs), or mini-strokes," said Dr. Raabe. "Our research
suggests we need to rethink the term 'asymptomatic.' Even when people
aren't 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."
Half of the patients in the study were considered symptomatic before
treatment, meaning they had suffered TIAs and had 70 percent blockage in at
least one carotid artery. The remaining 15 patients were asymptomatic,
meaning they had not suffered TIA, but their carotid arteries were at least
80 percent blocked.
Every year, about 700,000 Americans have a stroke. About a third of
those people die, making stroke the third-leading cause of death in the
United States. Approximately 30 percent of all strokes are the result of
clogged carotid arteries. Carotid arteries, located on each side of the
neck, are the main source of blood to the brain. Like arteries in the heart
and other parts of the body, the carotid arteries can become clogged with
plaque, potentially causing a stroke by cutting off blood flow to part of
the brain.
For many years, people with severely blocked carotid arteries had only
two options to attempt to prevent stroke: medication and surgery, called
endarterectomy, to open blocked arteries and clean them out. Surgery
involves a neck incision of up to seven inches.
In recent years, the combination of minimally invasive carotid
angioplasty and stenting is increasingly offered as an alternative to
surgery. The procedure involves making a small incision in the groin and
advancing a thin tube, or catheter, through the blood vessels to the site
of the blockage, inflating a balloon to open up the narrowed artery and
leaving behind a stent, a tiny metal mesh device that acts as scaffolding
to keep the artery propped open.
Studies show that both surgery and angioplasty with stenting can reduce
the risk of stroke in asymptomatic patients by half.
Early on, carotid angioplasty with stenting was considered risky
because in placing the stent, blood clots were often knocked loose and
could travel to the brain, potentially causing a stroke. Filter-like
devices were developed to catch the clots and prevent them from going to
the brain, but tiny clots can still escape and have been thought to
contribute to cognitive decline following treatment.
Dr. Raabe's study originally set out to determine if the filter devices
helped patients maintain cognitive function. The research team was pleased
to find that not only did brain function not get worse, it improved. The
study suggests that by opening up the artery, angioplasty and stenting
increases blood flow. Increased blood flow allows the brain more effective
access to neurocognitive reserves, outweighing negative effects of tiny
clots that pass through the filter. Several studies have looked at brain
function after surgery, with mixed results. While studies have shown that
blood flow to the brain improves after surgery, the invasiveness of
surgery, coupled with the required general anesthesia, may lead to
decreases in neurological function. "It's sort of a wash," said Dr. Raabe.
Considered to be the premier meeting on endovascular therapy, the
International Symposium on Endovascular Therapy (ISET) is attended by more
than 1,200 physicians, scientists and industry professionals from around
the world. The meeting pioneered the use of live cases to promote the
multidisciplinary treatment of vascular disease. ISET is presented by the
Baptist Cardiac & Vascular Institute, Miami.
International Symposium on Endovascular Therapy
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