ANAHEIM, Calif. — Being paralyzed was bad enough. But it was the thought of never playing golf again that persuaded stroke victim Bill Boyer to let doctors attempt an astonishing and highly experimental procedure in which they rerouted blood backward through his veins and into his brain.

“I walked out of the hospital five days later,” said the 61-year-old carpet installer from the Los Angeles suburb of Sylmar. “Four days after that, I went out and played nine holes of golf in the rain.”

The procedure involves the use of veins to feed blood to the oxygen-starved area of the brain cut off by the stroke. Normally, arteries carry oxygen-rich blood to the brain; veins carry the used blood back to the heart.

So far, doctors from UCLA Medical Center have tried the approach on six patients. Four have had virtually complete recoveries, escaping probable paralysis, while the two others were unchanged.

“There is a lot of excitement from our point of view, and the patients are ecstatic,” said Dr. John G. Frazee, a neurosurgeon who developed the procedure.

Boyer was lifting a box in his garage a year ago when suddenly his left side went numb and he fell flat on his face. He crawled to his truck and dialed 911 on his cellular phone.

By the time he got to the UCLA Medical Center, his left leg and hip were paralyzed. Frazee had permission from the Food and Drug Administration to try his approach on 10 patients. Boyer, if he agreed, would be his second.

Frazee explained the procedure: About 80 percent of strokes — Boyer’s included — occur when a blood clot gets stuck in an artery somewhere in the brain. Unless the clot dislodges by itself, as sometimes happens, all the brain tissue downstream from the clot is starved of oxygen and nutrients and begins to die.

At the time, there was no medicine for strokes, although this has since begun to change with the approval of TPA, a clot-dissolving medicine already widely used for heart attacks.

While the blood supply to part of Boyer’s brain was cut off, the blood drainage system — the veins — was free and clear. Frazee’s idea was to hook up the plumbing backwards and send blood shooting into the brain via the veins.

“The front door to the brain is blocked by a clot,” Frazee said. “We decided to use the back door.”

Frazee had been experimenting for eight years on baboons. He thought it would work, but it was, after all, an experiment.

“I’m an avid golfer,” Boyer said. “I decided to give it a chance.”

So 6 1/2 hours after he fell down, doctors hooked up a tube to a big artery in Boyer’s groin and pumped the blood to the veins in both sides of his neck. Next, they threaded the tube through the veins up into the back of his head. Finally, they partially inflated balloons to keep the blood from running back out.

The result: Blood flowed backwards through the veins throughout Boyer’s brain. It reached the parts cut off by the clot. Within 15 minutes, the numbness began to lift.

One of the other patients who underwent the procedure even regained his ability to speak. The two patients who were neither helped nor hurt were probably too old, had many other health problems and had gone too long after the stroke, Frazee said.

Doctors begin the procedure up to seven hours after a stroke starts, and they keep the blood circulating backwards for several hours, if necessary. By then, Frazee said, the clot usually dissolves by itself or is washed away by the pressure of the reverse-flowing blood.

Frazee and a colleague, Dr. Xia Luo, presented their results for the first time Thursday at the International Joint Conference on Stroke and Cerebral Circulation in Anaheim.

“It’s a radical idea,” said Dr. Marc R. Mayberg, a neurosurgeon from the University of Washington. “Everybody’s pretty excited to see if the promising animal work will hold up in humans.”