Operating all day March 3 and into the early hours of the next day, George Washington University surgeons saved a Rochester teacher's life in a 19-hour operation during which he was chilled for a time to 65 degrees, his heart and lungs were stilled and his brain activity was halted.

The surgeons then removed a deadly, snake-like tangle of blood vessels at the base of his brain, a rare abnormal growth that had paralyzed both his arms and legs one week before the operation and was threatening to cut off his breathing.

The heads of two operating teams that worked side by side for 24 hours, including the post operative recovery period, described the procedure yesterday.

They called the effort that saved Donald Hauck, 34, a "first." Similar growths -- artery and vein malformations sometimes called "angiomas" --have been removed before. But none so advanced had ever been removed successfully, they said.

"It's like dissecting out hundreds of tiny snakes -- you have to dissect them out individually without cutting them or damaging the nerves and the spinal cord," said Dr. Ayub Ommaya, a neurosurgeon.

"You work with micro-forceps and the brain and spinal cord, on this tangle about the size of a marble within an area only one to two inches wide, criss-crossed with nerves.

"You work with micro-forceps and sharp little micro-scissors through an operating microscope that magnifies everything 16 to 25 times.

"You have to work very slowly. You can't hurry."

In fact, neurosurgeon Ommaya, chest and heart surgeon Paul Corso and anesthesiologists Sidney Aidinis and Bernard Filner worked without change of clothes or a meal from 7 a.m. March 3 to 2:30 a.m. March 4.

"I had a couple of candy bars and Corso had some candy and a coke," Ommaya said. "I didn't drink anything. Then when it was all over, I suddenly felt this terrific thirst. Then

As for patient Hauck, he has so far recovered most of the use of his left arm and partial use of his right. He has some control of his leg muscles but he still cannot walk. Months must elapse before surgeons know whether the nerve damage he suffered will permit him to walk again.

But he is "doing extremely well," the doctors said, though he will not leave the hospital for another three to four weeks.

And he is alive.

Hauck's arterial-venous malformation, to use the doctors' term, was nestled just beneath his medulla, the bottom-most part of the stem of the brain. The brain stem is a conductor between the brain and spinal cord, crammed with essential nerve tracts and reflex centers. The medulla contains the center to regulate breathing.

As Hauck's malformation -- which he had had since birth -- grew, it caused more and more pressure on his nerves and finally the total paralysis of his arms and legs.

Doctors still hesitated to operate. It is difficult to remove the problem without killing the patient, they said.

Then his breathing started to deteriorate and there was no choice. He had been referred to Ommaya, who is both neurosurgery chief at the National Institutes of Health and a clinical professor at George Washington Hospital.

At 7 a.m. on March 3 Ommaya, Corso, who is assistant professor of surgery, and Aldinis and Filner set to work.

They began anesthetizing their patient and inserting what one observer called "an incredible array of monitors to follow all vital functions, blood pressure within vessels and so on."

They also linked the vessels leading from his heart to an artificial heartlung machine. As soon as he was asleep, they began cooling him with ice packed around his body.

It was 11 a.m. before they were ready to begin operating. There were 17 persons -- surgeons, assistants, anesthesiologists, nurses, technicians --now in the room.

With the patient propped onto his left side, one operating team under Corso worked inside his chest, while Ommaya cut into the back up into the patients neck to reach the defect and remove intervening structures, including parts of some vertebrae.

"Figuring out how to position him was one of the tricky parts," Ommaya said. "We had to plan a position so we could both work. I was looking practically upward with my hand reaching up during the whose procedure."

In this way, the afternoon passed, with Ommaya isolating and snipping out tiny blood vessel after blood vessel. Then came the point when he had to remove the entire remaining structure.

"Now I asked that the entire circulation be stopped," he said. This and the chilling, he explained, minimized possible damage to surrounding brain and nerve cells.

Chilled blood first was circulated through the patient's body until, in Corso's words, he was "at about the temperature where President Carter wants you to keep your rooms." By this time the brain, heart and blood flow were all in dormant conditions.

In 35 minutes of intense work the remaining defect was sliced away.

At 2:30 a.m. the operation was over. Ommaya and Corso after a while snatched brief morning naps but returned to their patient until, at 7 a.m., they felt they could go home.

In sum, the surgeons reported yesterday, none of the elements of their operation -- profund cooling or delicate cutting -- was new.

But the totality added up to a new result for the medical records. And for patient Hauck.