Capture and removal of a thrombus blocking the flow of blood to the brain, and not just the intake of special drugs, significantly increases the likelihood of recovery after a stroke. To this conclusion came two new studies.
A more ambitious study found that the above procedure almost halved the mortality rate due to a stroke.
Since previous studies failed to prove the benefits of removing blood clots, recent work in this area should heighten interest in the devices used in the treatment of stroke.
In the research, Medtronic devices were used. Earlier, in December 2014, a large study conducted by Dutch scientists also revealed the benefits associated with the extraction of blood clots from the arteries.
The research report was published in the New England Journal of Medicine.
In the ESCAPE experiment, described by the first research work, which was conducted in 22 medical centres around the world, 53% of 120 patients with tube thrombus removed (the tube was placed in a blood vessel) regained their functionality after 90 days. Of the 118 people who received standard thrombolytics, only 29% recovered completely. The mortality rates in these two groups of patients during the first three months after the stroke were 10.4% and 19%, respectively.
A second study (EXTEND-IA), conducted by Australian scientists, found that 24 hours after the treatment, all the oxygen-deficient brain tissue of 35 patients with the removed thrombus was again supplied with blood. In the second group, cerebral blood supply was restored in 37% of patients (taking thrombolytic drug Alteplase). After three months in the first group, the functionality was restored in 71% of patients, in the second – to 40%.
Both studies were discontinued relatively early, as the benefits of extracting blood clots reached a truly impressive value. One of the reasons why the results of experiments were much higher than in previous works, the researchers call the careful selection of participants. In particular, occluded arteries were identified by scanning, and some patients needed “collateral circulation” (blood flow bypassing the blockage).
Without collateral circulation, the brain dies very quickly, sometimes for fifteen minutes. In this case, it is impossible to save a person.
Another reason for the success could be the speed: many blood clots were removed within 84 minutes after the formation, that is, an average of one hour earlier than in the experiments that did not give a positive result.
A new study conducted in Norway demonstrates that the procedure in which a doctor uses a catheter to ease complications of deep vein thrombosis (HTG) appears to be useful. GTV consists in the formation of thrombi of the blood vessels of the legs, which can move into the lungs and become even more dangerous. Almost half of the patients with GTV can also develop a tangle of complications, called post-thrombotic syndrome, characterized by pain, swelling, a feeling of heaviness and deterioration of the skin. A new study examined 189 patients with TLV who had only normal blood thinning therapy or the same therapy plus additional directional catheter thrombolysis (NCT) using directed destruction of the thrombus with Alteplase.
According to the report of the American College of Radiology and the Society of Radiologists of North America in the tubing, angiography is used to carry out a special medication or medical device to localize the thrombus and dilute it. After two years of follow-up, complications related to the TLG occurred in 41 percent of patients who underwent additional tuberculosis therapy and 56 percent received conventional therapy, according to a research team led by Dr Per Morten Sandset of the Department of Hematology at Oslo University Hospital.
This means that additional tuberculosis therapy reduces the level of complications by about one quarter. Since every seven patients underwent additional tuberculosis therapy, one case of these postthrombotic complications was prevented. However, there were 20 bleeding complications associated with therapy, including three important, and five clinically relevant cases of bleeding.
The study appeared on December 13 online in the magazine “Scalpel”, and on the same day was to be presented at the annual conference of the American Society of Hematology in San Diego. Additional tuberculosis therapy reduced the level of complications for patients with GTV in comparison with only blood thinners, “but it was associated with a small additional risk of bleeding,” the researchers wrote. “But compared with standard therapy, this risk of bleeding seems acceptable,” they added.
One expert agreed that the results of these studies could be valuable. “This study suggests the use of directional catheter thrombolysis as a routine and at the same time safe and effective therapy for patients with leg tuberculosis,” said Dr Robert Louisstein, director of the angiography at the Mount Sinai Medical Center in New York.
