Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Clot-Busting’ at Stroke Site is Viable Option

22.06.2004


A small Ohio study has offered the first published evidence that aggressively treating brain blood clots at their source soon after symptoms start can produce a good outcome for many stroke patients.



In the study, published in a recent issue of the journal Neurosurgery, 50 percent of stroke patients had little or no neurological disability one to three months after clot-dissolving medication was delivered directly to the site of the blockages, compared to 39 percent of patients with similarly good outcomes documented in a large national trial of intravenous (IV) drug treatment for stroke. In all cases, time was an issue: The drugs in both trials were administered within three hours of the onset of symptoms.

“The results tell us what many of us suspected – that targeting the problem and delivering drugs right to the problem is a better option for appropriate stroke patients,” said Eric Bourekas, an interventional neuroradiologist at Ohio State University Medical Center and lead author of the study.


Researchers at OSU Medical Center and Case Western Reserve University compared patient outcomes from their institutions to the outcomes reported in 1995 after a study led by the National Institute of Neurological Disorders and Stroke. In that large trial, patients who were treated intravenously with recombinant tissue plasminogen activator (rt-PA) within three hours of symptom onset were at least 30 percent more likely to have good outcomes compared to patients on placebo. That study led to the intravenous use of rt-PA as the only federally approved clot-dissolving treatment of ischemic stroke – the roughly 80 percent of strokes caused by blockage of a blood vessel.

The two Ohio centers treated hundreds of stroke patients using the intra-arterial (IA) method of drug delivery over the time period observed, between 1993 and 2002, but only 36 patients received the medication within three hours after symptoms began, matching the conditions of therapy measured in the NINDS trial. These patients also had the same median admission score – based on a common stroke severity analysis tool – as the NINDS patients.

The intra-arterial treatment involves first obtaining X-rays of the affected blood vessels, or angiograms, by introducing a contrast agent to the bloodstream. Once the blockage is identified, physicians insert a catheter in the leg that is guided through the neck to the brain and the site of the clot. Physicians at OSU and CWRU used a different clot-dissolving agent, urokinase, until it became unavailable in the United States, and then began using rt-PA, the approved drug for IV use in stroke patients. Physicians stopped administering the drug either once the vessel completely opened or when the maximum drug dose was reached.

“Based on its symptoms, stroke can look like something else, so an advantage of the IA therapy is that we are much more clear about what we’re treating. We study the blood vessels, we see the clot, we know we’re treating a stroke, and the level of confidence is much higher,” Bourekas said. “We also may use less of the drug, which may reduce the risk of hemorrhage, because we can watch the clot dissolve and stop administering the drug as soon as the vessel opens up.”

The biggest advantage demonstrated by the study is that administering drugs at the clot site rather than through an IV is more likely to reopen the vessel, considered a major contributor to improved stroke outcomes. Partial or complete recanalization occurred in 75 percent of the patients treated with IA therapy at OSU and Case Western, compared to the 20 percent-to-50 percent range of recanalization in most IV treatment trials, said Andrew Slivka, a study co-author, neurologist and director of OSU Medical Center’s stroke division.

The rates of patient deaths and symptomatic hemorrhages were comparable to rates in other stroke studies, and tended to be associated strongly with much more severe strokes rather than treatment method. Angiography and catheterization of blood vessels in the head do carry risks, but the Ohio study resulted in only one catheterization-related complication that did not cause neurological damage, the researchers said.

Having a 24-hour stroke treatment center is required to achieve the best results with the intra-arterial therapy, the Ohio State researchers noted. “A team of radiologists and neurologists must be available around the clock and be ready for that rapid response,” Slivka said. “When blood flow to the brain is compromised, the brain won’t tolerate it for very long. Time is critical. The faster we can dissolve the clot to re-establish blood flow to that part of the brain, the more likely we are to have a good result.”

Patients’ realization that they’re having a stroke and their ability to get to a hospital are major variables, as well. Major stroke symptoms include a sudden inability to move a leg or arm, slurred speech or being unable to talk, sudden blindness, a sudden headache or numbness throughout one side of the body.

Finally, the researchers acknowledge they cannot recommend IA therapy across the board given the small size of their study. Bourekas said a larger study is needed to prove that “clot-busting” at the stroke site offers better chances for a good stroke outcome than IV therapy, and said researchers are hopeful a large, federal trial will be done to further test the therapy’s effectiveness.

Additional study co-authors were Rajul Shah of OSU Medical Center and Robert Tarr, Jeffrey Sunshine and Jose Suarez of the University Hospitals of Cleveland and CWRU.

OSU | newswise
Further information:
http://www.osu.edu

More articles from Studies and Analyses:

nachricht Self-organising system enables motile cells to form complex search pattern
07.05.2019 | Westfälische Wilhelms-Universität Münster

nachricht Mouse studies show minimally invasive route can accurately administer drugs to brain
02.05.2019 | Johns Hopkins Medicine

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

Im Focus: Tube anemone has the largest animal mitochondrial genome ever sequenced

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....

Im Focus: Tiny light box opens new doors into the nanoworld

Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.

Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...

Im Focus: Cost-effective and individualized advanced electronic packaging in small batches now available

Fraunhofer IZM is joining the EUROPRACTICE IC Service platform. Together, the partners are making fan-out wafer level packaging (FOWLP) for electronic devices available and affordable even in small batches – and thus of interest to research institutes, universities, and SMEs. Costs can be significantly reduced by up to ten customers implementing individual fan-out wafer level packaging for their ICs or other components on a multi-project wafer. The target group includes any organization that does not produce in large quantities, but requires prototypes.

Research always means trying things out and daring to do new things. Research institutes, universities, and SMEs do not produce in large batches, but rather...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Concert of magnetic moments

14.06.2019 | Information Technology

Materials informatics reveals new class of super-hard alloys

14.06.2019 | Materials Sciences

New imaging modality targets cholesterol in arterial plaque

14.06.2019 | Medical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>