Summer 2012 - What Does it Mean to Intervene
One definition of an intervention is the act of “interfering with the outcome or course especially of a condition or process.” When describing today’s highly advanced stroke treatments, commonly known as interventions, this definition holds true in lifesaving ways.
An ischemic stroke occurs when a blood clot lodges in an artery leading to the brain. The process of brain damage and eventual death can begin because life-giving oxygen and nutrients found in the blood cannot reach the brain. Stroke interventions, in the form of intravenous medications and tiny devices, are now used at WakeMed and many other U.S. health systems to stop the life-limiting process stroke can bring about.
Thrombolytics, or lytics, are essentially clot-busting medications. “Lytics can break up the platelets, fibers and connections that make up a clot and reopen the artery to allow blood and oxygen to flow to the brain,” says Rhonda Gabr, MD, PhD, a neurologist with Raleigh Neurology. Dr. Gabr and her colleagues treat patients in their practice as well as emergent patients in the WakeMed Emergency Departments, located at the WakeMed Raleigh Campus, Cary Hospital, WakeMed North, Apex Healthplex and Brier Creek Healthplex.
Thrombolytic stroke interventions have been in use since the mid-1990s. The most common thrombolytic used is tissue plasminogen activator (tPA). TPA is a protein that actually exists in the cells that line our blood vessels. Its purpose as a naturally occurring protein in our bodies is to act as a thrombolytic to break down blood clots. When it is overwhelmed and cannot do its job on a large clot, a synthetic version of tPA can be intravenously administered to break it up and restore blood flow to the brain.
“We have seen stroke patients who meet the criteria for lytic administration make remarkable recoveries,” says Dr. Gabr. In fact, the use of tPA and other interventional stroke treatments has significantly reduced disability related to stroke. Still, thrombolytics can only be used for a small number of ischemic stroke patients. For a patient to qualify for tPA administration, the patient must:
- Be treated within three hours of symptom onset. “This is the most important factor for lytic interventions,” emphasizes Dr. Gabr. She explains that knowing when symptoms actually began can be difficult. “Stroke symptoms can come on slowly or even when you are sleeping,” she explains. “Getting to the hospital and having the appropriate tests within that three-hour window can be difficult.”
- Have normal blood pressure and platelets.
- Not take blood thinners.
- Have no history of intracranial hemorrhages.
- Not be a metastatic cancer patient.
- Have no recent surgeries, particularly involving a vascular procedure.
For Patients Who Do Not Qualify for tPA
“We have a second-line intervention for patients who do not qualify for lytics and do not respond to traditional stroke care,” said Dr. Gabr. This intervention comes in the form of highly advanced catheter technology.
“Clot retrieval devices can be used to facilitate restoration of blood flow in patients who are outside the three-hour window with the potential for good outcomes,” says Dr. Gabr. She noted that, when she is working in the WakeMed Emergency Departments, she often encounters stroke patients who may qualify for a catheter intervention and makes the suggestion to cardiologists. Interventional cardiologists ultimately perform these types of procedures and are readily available at the WakeMed Raleigh Campus Emergency Department to treat stroke patients.
There are two types of clot retrieval devices – the Merci® Retrieval System and the Penumbra System. The Merci retriever is a coil on a catheter that is threaded to the clot in the blood vessel of the brain. Once the coil reaches the clot, the interventionist pushes it forward so it wraps around the clot. The clot can then be pulled out of the artery restoring blood flow to the brain. A Penumbra device is also threaded into the artery via a catheter. Instead of pulling the clot out of the artery, the Penumbra device uses suction to remove the clot.
“The clot retrieval devices are most appropriate for patients who have large vessel blockages that are confirmed by specialized CT imaging,” says Dr. Gabr. “We have also seen very positive results in very young stroke patients with posterior circulation (back of the brain) strokes.”
Good Conventional Stroke Care
Interventional stroke treatments aside, Dr. Gabr stresses the importance of good conventional stroke care for every stroke patient before any interventions can take place.
“First and foremost, the stroke patient needs to get to the hospital as soon as possible,” says Dr. Gabr. In addition, patients need to have blood tests as well as a CT scan (computed tomography perfusion imaging) to determine if and where a clot exists. These necessary steps add to the time it takes for a patient to be treated, and time is brain. “The safest and best way to get to the hospital is to call 9-1-1,” says Dr. Gabr. “We have great EMS providers in our area who can stabilize the patient and help physicians and WakeMed prepare for the patient’s arrival.”
In addition to a safe and swift arrival at the hospital emergency department, patients should:
- Lie as flat as possible to encourage blood flow.
- Be given aspirin (in some cases) and intravenous fluids.
- Be kept stable to avoid sudden drops in blood pressure.
Will I Have Another Stroke?
It is unfortunate, but a stroke patient, particularly one who has uncontrolled risk factors, is at risk for another stroke. “I never tell a stroke patient they won’t suffer another stroke,” says Dr. Gabr. “It is, unfortunately, always a possibility. But patients can take steps to lower their risk of a second stroke.”
Dr. Gabr notes that the type of stroke a person has and where the blockage occurred can impact a person’s risk of suffering a second stroke. “Patients can’t do anything to alter the etiology of their original stroke, but they can reduce their risk by taking good care of themselves,” she adds.
Know the Symptoms
Here is a simple test from the National Stroke Association to help determine if a person is having a stroke.
Ask the person to smile. Does one side of the face droop?
Ask the person to raise both arms. Does one drift down?
Can the person repeat a simple sentence?
See any of these signs? Act fast, and call 911 to get to the nearest hospital where acute stroke treatment is readily available.
STROKE RISK FACTS:
Men vs. Women
Stroke Rate — Overall, while more men have strokes than women, one in six women will have a stroke. In the age groups 35 to 44 and 85+, more women than men have strokes.
Death from Stroke — Of the Americans who die as a result of a stroke, 60 percent are women.
Migraine Headaches — It is important to note that more women than men suffer from migraine headaches. Chronic migraines are a risk factor for stroke.
Stroke Prevention Guidelines
- Stay in Control — If you have high blood pressure, diabetes, high cholesterol or atrial fibrillation, work with your doctor to get and keep them under control.
- Stop Smoking.
- Limit or Eliminate Alcohol Use.
- Exercise — at least 30 minutes a day.
- Blood Circulation — Talk to your doctor to understand whether or not you have good circulation.
- Consume Less Salt.
- Stroke Symptoms — Know what they are and listen to your body.
Dr. Gabr has special advice for her younger patients who have had strokes. “I tell them that they need to become really good friends with their primary care doctor who can track their vascular health throughout their life,” she says.
Above all, people who have survived a stroke need to focus on living happy, healthy lives. Because physicians now have the ability to intervene with advanced medication and technology when a stroke occurs, that happy, healthy life is an even greater possibility.