Stroke Treatments and New Tiny Vacuum Cleaner Device

A stroke (cerebrovascular accident - CVA 1) is a disease occurs when a blood vessel (arteries leading to the brain) which supplies the brain with oxygen and glucose (Form of sugar supplying the brain cells with fuel or energy 2) becomes impaired by a blockage, clot (thrombosis) or bursts. 4 Third ranking cause of death behind heart disease and cancer is a stroke. 7 The brain has four major blood vessels. Risk factors attributed to narrowing of a blood vessel in the brain: High cholesterol, diabetes, smoking, high blood pressure (hypertension) and age ("the older a person gets, the greater the risk of a stroke." 4). Other factors considered to cause a stroke: Heart attack increase the likely hood to have a stroke, African Americans have a greater risk than Caucasians, sickle cell anemia, and history of migraine headaches increase the risk for ischemic stroke. 4

A 'mini-stroke' is short-lived episode (Approximately last up to 20 minutes and lingering symptoms for up to 24 hours. 4) when a blood vessel in the brain is temporarily impaired or transient ischemic attack (TIA - Accounts for 80 - 85% of all strokes. 4). 3 Fifteen percent of strokes are Hemorrhagic strokes: When blood vessel in the brain breaks (Subarachonoid hemorrhage - bleeding occurs between the surface of the brain and skull. 8) or hemorrhage into the brain (Intracerabral hemorrhage 8) tissue. Hemorrhagic strokes accounts for about 30 percent of all stroke deaths. 5 A clot that forms in the body can dislodge and travel to an artery in the brain causing transient ischemic attack. When the largest blood vessel in the brain (carotid artery) has TIA, the side opposite the blockage: Movement or sensation on one side of the body is curtailed by paralysis affecting the arm, leg (trouble walking or loss of balance), face, speech and sometimes vision in one eye. 3 The paralysis of a stroke can be temporary or permanent neurologic impairment. 4

When a stroke occurs immediate medical attention is required, and recommended the person should lie flat to optimize blood flow to the brain. Also, should vomiting occur advisable to position the person on their side prevent choking. 3 Fortunately during the past 20 - 30 years advancement in medical treatments has significantly reduced the number of deaths attributed to strokes in the United States. 6 "May is National Stroke Awareness Month. In 2008, an estimated 780,000 persons in the United States will have a stroke; of these 150,000 will die from stroke, and 15% - 30% of stroke survivors will be permanently disabled. " 7

Standard treatments for a stroke: Clot-busting drug called tissue plasminogen activator (tPA - Approved by the FDA in 1996) administered intravenously within three hours, first signs of a stroke."After that point, the risks of bleeding in the brain may outweight the potential benefits." 9 Clot-busting cork-screw (MERCI - Mechanical Embolus Removal in Cerebral Ischemia) approved by the FDA in 2004: "the device is threaded into the blood vessels of the brain using a microcatheter and a tiny corkscrew tool is used to pierce the clot and physically remove it." This approach removes a blood clot in the brain, useful when tPA is not advisable after three hours from the onset of stroke symptoms and when ischemic stroke clot is too big to be effectively treated with a clot busting drug. Also, MERCI Retrieval System is used up to eight hours after the stroke begins. 10

January of 2009, the Food and Drug Administration approved a tiny vacuum-cleaner-like device for removing blood clots in the brain called Penumbra. 11 The Penumbra System is used by neuro -interventional specialists. 15 A cerebral angiography images the blood vessels of the brain and blood flowing through them. "Cerebral angiography involves passing a catheter into a large artery in the groin and advancing the catheter up through the carotid artery (Supplies the head and neck with oxygenated blood 16) that leads to the brain under X-ray guidance and monitors. A dye (contrast agent) is then injected into the carotid arteries and X-ray is used to image the dye flowing through the blood vessels." When a large blood clot in the brain is identified, the Penumbra is inserted through the catheter and advanced through the blood vessels until reaching the obstruction. 11 One of the devices of the Penumbra is used to dislodge the clot. 13 "A suction device then grasps the clot for removal." 11 According to a clinical study of 125 ischemic stroke patients, Penumbra restored blood flow 82%. 12 One-third of the clinical patients were able to return to normal activities without any adverse effects. 11 Cameron McDougall, MD, chief of endovascular neurosurgery at the Barrow Neurologicial Institute in Phoenix said: "There were no serious adverse events associated with the procedure and nearly 60% of patients were better neurologically by the time they left the hospital." 12

Penumbra compared to plasminogen activator (tPA), has better results, since tPa works in about 40% of patients. Also, majority of brain stroke patients arrive after the first three hours from the onset of symptoms, making tPA no longer an effective treatment option. 12 (Or after Iv tPA is administered may not prove effective by removing the brain clot 13). 11 Penumbra compared to other medical devices such as Clot-busting cork-screw (MERCI - Mechanical Embolus Removal in Cerebral Ischemia) less likely cause damage to the walls of the blood vessel. 13 Penumbra proven to remove blood clots in the brain from up to eight hours from the onset of symptoms. 11

Limitation us of Penumbra depends upon the size of the clot, accessibility to reach the clot and severity of the stroke. When a large clot is located in the brain, Penumbra may only be able to remove a portion of the clot. 11 Also, a patient's physician must estimate if the extent of the stroke has killed to the extent of brain tissue or enough brain tissue can be salvaged, incurring the risk of the procedure: May trigger swelling or brain hemorrhage when the blood vessel in brain is opened, surges in oxygen. 14

First medical center to employ Penumbra clot retrieval system device is Cedars-Sinai Department of Nuerosurgery's Neurovascular Center. 13

References:

1.) Stroke - http://www.medicinenet.com/stroke/article.htm

2.) Nourish - Carbohydrates Fuel Your Brain - http://www.fi.edu/learn/brain/carbs.html

3.) What is a Stroke? - http://www.strokeassociation.org/presenter.jhtml?identifier=3030066

4.) Stroke - http://www.umm.edu/altmed/articles/stroke-000159.htm

5.) HEMORRHAGIC STROKE - http://www.mageerehab.org/hemmorhagic-stroke.php

6.) Stroke - Definition - http://www.mayoclinic.com/health/stroke/DS00150

7.) National Stroke Awareness Month - -- May 2008 - http://www.umm.edu/altmed/articles/stroke-000159.htm

8.) Hemorrhagic Stroke - http://www.strokesurvivors.ca/new/Hemmorrhagic.php

9.) Clot - Busting Stroke Drug's Benefit Reaffirmed - http://www.webmd.com/stroke/news/20040902/clot-busting-stroke-drugs-benefit-reaffirmed

10.) Corkscrew Device Offers New Hope in Stroke Treatment - http://stroke.about.com/b/2006/08/12/corkscrew-device-offers-new-hope-in-stroke-treatment.htm

11.) Penumbra: New Treatment Option for Stroke - http://www.froedtert.com/SpecialtyAreas/StrokeProgram/ProgramsAndServices/AdvancedTreatments/Penumbra.htm

12.) 'Vacum' Device is a Clot Buster - http://www.webmd.com/stroke/news/20080222/vacuum-device-is-a-clot-buster

13.) Innovative Treatment for Strokes Due to Blood Clots - http://www.csmc.edu/13445.html

14.) New Treatment can clear brain clots - http://www.boston.com/news/health/articles/2008/01/29/new_treatment_can_clear_brain_clots/?page=full

15.) First Multi-Center Real World Clinical Data on Use of the Penumbra System in Acute Ischemic Stroke is Presented at the International Stroke Conference's "Best Science of the ISC" Session - http://www.andhranews.net/Intl/2009/February/21/bwi-First-Multi-Center-91021.asp

16.) Common carotid artery - http://en.wikipedia.org/wiki/Carotid_artery