stroke victims will now have better chances of survival. In a pathbreaking experiment, doctors from ucla Medical Centre, California, have developed a technique that reverses the plumbing of the body's circulatory system by using veins to supply blood to oxygen-starved parts of the brain. The new approach has been tried on six patients so far. Four of them have almost completely recovered.

The doctors had tried the procedure called retrograde transvenous neuroperfusion on baboons for eight years before trying it on humans. "There is a lot of excitement from our point of view and the patients are ecstatic,' said John Frazee, the neurosurgeon who developed the procedure. Frazee will try the technique on four more patients and if they also show positive results, the experiment may be expanded to other medical centres. About 80 per cent of strokes occur when blood clots clog the arteries that carry blood through the brain. Unless the clots quickly break up by themselves, brain cells start dying due to lack of oxygen and nutrients.