Blood Clot Ultrasound

A stroke occurs when the blood supply to an area of the brain is cut off, causing the oxygen-deprived brain cells to die. A stroke may be caused by a clot or from a hemorrhage. In an intracerebral hemorrhage, an artery in the brain ruptures. Blood leaks out of the vessel into the surrounding brain tissue.

An intracerebral hemorrhage damages brain tissue in two ways. First, the ruptured artery means blood can’t get to a part of the brain fed by that blood vessel. Second, the leaking blood pools inside the brain, putting extra pressure on the surrounding brain tissue, damaging those cells as well. Signs depend upon the location and size of the bleed. Patients may have a sudden, severe headache, nausea, vomiting, confusion, tiredness, sudden weakness or numbness of the face or one side of the body, vision problems, speech problems, seizures or loss of consciousness.

The American Heart Association estimates 795,000 strokes occur annually in the U.S. Intracerebral hemorrhage accounts for 10 to 15 percent of all strokes. Although less common than those caused by a clot, hemorrhagic strokes are more likely to cause death. About 40 to 50 percent of patients having an intracerebral hemorrhage die within 30 days. 70 percent of the survivors are left with some type of impairment.

Treating Clots Caused by Brain Hemorrhage

Blood that leaks from an intracerebral hemorrhage pools inside the brain, eventually congealing into a gel. David Newell, M.D., Neurosurgeon with the Swedish Neuroscience Institute in Seattle, WA, says it can take weeks for the body to break down this jelly-like clot. In the meantime, the surrounding brain cells are subjected to damaging pressure. Patients may need to be monitored in the hospital or intensive care unit for weeks to months.

Doctors may operate to reduce brain pressure and further risk of damage from the clot. To access the source of bleeding and the clot, doctors may either remove a small piece of the skull or drill a hole into the skull. The bleeding is stopped and the coagulated blood is suctioned away.

Ultrasound for Intracerebral Hemorrhage

Newell says the traditional surgical techniques to remove blood clots after a hemorrhage have their own set of risks, including rebleeding. Recently, he tested a technique that uses a combination of the clot-busting drug, tPA, with ultrasound to target the congealed clot after an intracerebral hemorrhage.

The technique uses the EkoSonic® Endovascular System by EKOS. First, a tiny hole is drilled into the skull. Then, using a GPS-like navigation tool, doctors feed a catheter into the hemorrhage. Once in place, the ultrasound-tipped catheter goes to work. The ultrasound waves allow the tPA to permeate the clot, speeding the ability of the drug to dissolve the clot. The treatment is delivered continuously for a total of 24 hours. The liquefied clot is then drained through another catheter into a collection bag.

A small feasibility study was recently completed for 10 patients with clots from an intracerebral hemorrhage. Newell says with tPA alone, it can take three to four days for a clot to dissolve, subjecting the brain to prolonged pressure. With the EkoSonic® Endovascular System, all the patients responded to the treatment within 24 hours.

Researchers must apply for FDA approval before testing the technique in a larger group of people. Newell is hopeful the treatment will be available to other doctors within a few years.

For general information on stroke or intracerebral hemorrhage:

American Heart AssociationAmerican Stroke AssociationNational Institute of Neurological Disorders and StrokeNational Stroke Association