PROCEDURE REVERSES MEDICAL THINKING : CHANGING DIRECTION OF BLOOD FLOW COULD REVOLUTIONIZE TREATMENT.

Byline: David Bloom Daily News Staff Writer

Given the one-way nature of the body's blood flow, even the most veteran neurosurgeons scratch their heads when Dr. John Frazee talks about his revolutionary way to prevent paralysis after strokes:

He reverses the flow of blood through the brain's plumbing, thereby resuming the delivery of oxygenated blood, flushing out the killer clot and warding off almost-certain paralysis and loss of vision, speech and memory.

``I run into this `you-can't-do-that' concept all the time,'' said Frazee, a neurosurgeon at UCLA Medical Center.

``I tell them to go down to the airport and look at a 747 and tell me that's going to fly. It doesn't make sense and yet we know somehow it works,'' Frazee said during an interview Friday.

The initial results are promising: Four of six stroke victims have showed full or almost full recovery within hours. Two patients didn't respond well because, doctors said, they were not operated on soon enough and had other major health problems.

The most dramatic recovery was that of Bill Boyer, a Sylmar man whose partial paralysis disappeared within half an hour of the start of treatment.

The treatment was a sensation at this week's international stroke conference in Anaheim sponsored by the American Heart Association. If its success continues in trials, the procedure could revolutionize how Americans deal with one of their biggest health threats.

Strokes occur when clots or ruptures in capillaries starve brain tissue of needed oxygen and nourishment.

It is the nation's third biggest killer, taking the lives of about 150,000 people a year. And when it doesn't kill, it can leave survivors paralyzed, mute or otherwise disabled. It is the leading cause of disability in adults, striking some 400,000 people a year.

Other than Frazee's procedure, there is just one treatment approved for use by the Food and Drug Administration. Injections of a drug called tPA can dissolve clots.

But tPA treatment, approved last year, provides only moderately better results than a placebo three months after treatment, according to studies published in the New England Journal of Medicine.

And the drug works only if injected within the first three hours of a stroke's onset, said Frazee's research assistant, Dr. Xia Luo, also a neurosurgeon.

Frazee's technique seems to be more long-lasting, and it takes a completely different and, for many, totally counterintuitive approach.

Called retrograde transvenous neuroperfusion, the treatment calls for catheters to be snaked up into the jugular vein on each side of the neck until they reach a major vein in the back of the head called the venous sinus.

Blood tapped from the victim's femoral artery in the groin is gently pumped into the vein in the opposite direction of its usual flow. The blood flows to what had been downstream of the clot, an area that is being deprived of oxygenated blood.

``That's why we call it the back-door treatment,'' Luo said.

Tiny balloons in the catheter ends are expanded to keep the pumped blood from flowing back down the vein, so it can flow out of the brain through other veins to the heart.

Reverse-pumping is possible only in the brain, because everywhere else in the body, the veins have special valves that allow one-way flow. ``Only the veins in the brain don't have valves, so we were lucky,'' Luo said.

The technique also seems to cause the clots to break up, rather than merely dislodging them so they can cause a problem elsewhere, Frazee said.

Frazee got the idea a decade ago from a cardiologist friend who used the technique with heart surgery.

Although Frazee received FDA approval for a trial in 1989, he and his team spent eight often-frustrating years of trial and error with baboons to perfect the technique.

``Then we determined that the catheter's position is crucial,'' Frazee said.

By positioning the catheters further into the brain's veins, it allowed blood seeping out of the head from other vessels to get past the catheters, while still ensuring the pumped blood got to the clotted tissue.

Like tPA, the new technique works only if it is administered soon after the stroke, Luo said.

Six to seven hours after the stroke, the brain tissue begins to die and no known treatment can cause it to regenerate, the doctors said. The trial has been held up because relatively few stroke victims seek treatment within that short time frame, Luo said.