Protection against stroke
A filter for the brain
It is rare, but it happens: a stroke that occurs because of a replacement heart valve. To protect the patient against such a catastrophe, developed filters that protect the brain during surgery. But experience imbued with it.
If the aortic valve procedure “Tavi”, the new valve through a catheter between the main artery (aorta) and the left ventricle is placed. (Image: Klinik Hirslanden)
Of the four valves in the heart sickly aortic value extra often. It is deeply calcified, it must be replaced. This is done usually with a catheter procedure. In this case (implantation of transcatheter aortic valve), the artificial valve is usually placed in the femoral artery in place between the left ventricle and the aorta (aortic) – and placed there instead of the diseased valve. The old cover is not removed, but is pressed against the wall of the blood vessel.
Diversion of head
It sounds simple, but it can lead to a stroke patient in rare cases. Because if the new valve can separate the former insertion valve and blood vessels lime and other materials; This material can then be pulled through the bloodstream in the brain. It was to avoid such incidents filtration systems developed with the direction of the aorta arteries branching head must protect materials mitgeschwemmtem recent years. What such a protective device brings together researchers from the University of Leipzig, they just tested in 100 patients. For narrowed aortic valve was replaced with “Tavi” – 50 of them with protective filter, 50 ohne.¹
As Axel Linke and his colleagues were able to show that the filter is not only the number of magnetic resonance imaging (MRI of the brain emboli) to reduce the detected suspicious lesions, but also its size. So a clear case for the filter, you might think. Unfortunately, this is not because the clinical relevance of the results of the MRI questionable. Thus, the researchers found both groups to ten percent after surgery, patients neurological abnormalities – including those whose brains “protected” through the filter.
What the layman surprised the cardiac surgeon heart Sacha Salzberg Hirslanden in Zurich clear causes. First, the filter is capable by itself begins brachial embolism at his disposal in the artery. Second, you can Kalkstückchen individual can only dissolve after participation when the filter is removed long ago. Third, were not all the brain material mechanical exfoliation sweeps back. The inclusion of the heart, among other things, allow the coagulation Salzberg said. This could include – bound clot – causing embolisms.
With these concerns in Zurich doctor I do not want to denigrate the experience with filtering systems. He simply points out that so far the evidence is still waiting for the effort and risk associated with the direction of the patient mark. This group also provides links to Leipzig. What now are the largest studies necessary to determine the protective effect of the filter on neurological and cognitive functions of patients, according to researchers.
Surgery or catheter?
A quite different to avoid “Abspicken” material in the brain is disconnecting the aorta. This is done during the replacement of the aortic valve surgery. Disadvantage: The patient must be connected to this operation to a heart-lung machine, which eliminates the replacement catheter-based valve. What is the patient approach would be better, would depend on the risk of surgery and other patient factors, Salzberg said. The decision is therefore better to take a heart, a heart surgeon, cardiologists and anesthesiologists and key conventional therapies.