The Year in Science: Medicine 1997

Backward Blood

By Jeff Goldberg|Thursday, January 01, 1998
RELATED TAGS: HEART DISEASE
For the half million Americans who suffer a stroke each year, the odds of recovery are grim. Only about one in five recovers completely, and one out of three dies. But last February, John Frazee, a neurosurgeon at the ucla Medical Center, introduced an experimental procedure that may one day improve those odds. Most strokes occur when a clot in a cerebral artery cuts blood flow to the brain, depriving neurons of oxygen and ultimately killing them. Frazee has found a way to use veins to deliver oxygen-rich blood to the affected neurons—in effect reversing normal blood flow in a part of the brain.

The method, which has been tested on baboons, is called retrograde transvenous neuroperfusion. Frazee describes it simply as a backdoor approach to treating stroke. The front door to the brain is blocked by a clot, he says. This is another way in.

With the patient sedated but not asleep, blood from the large femoral artery in the groin is drawn through a mechanical pump into catheters inserted into the jugular veins on either side of the neck. Guided by X-rays, Frazee maneuvers the thin tubes toward a pair of veins in the back of the head. Tiny balloons near the tips of the catheters are then inflated to block normal blood flow and permit oxygen-rich arterial blood to be pumped backward through the veins toward the affected artery. This blood is then drained normally through other veins leading back to the heart.

The treatment offers patients precious time, Frazee explains. Neuroperfusion can be started in 30 minutes and the pump can keep blood circulating backward for several hours. During that time clots may dissolve naturally, or doctors can begin emergency measures—such as administering a clot-busting drug or performing surgery.

Last February, Frazee announced the results for his first six patients; he has since performed the procedure on two others. Three have fully recovered, three showed some improvement, and two remained unchanged. Larger trials will soon begin in several hospitals. But even with very good results, it will take time for such an approach to gain acceptance. Intuitively, for most medical people, says Frazee, making blood go backward through the venous system is like driving the wrong way on the L.A. freeway.
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