A young man's penis, amputated in a brutal act of revenge, has been reattached here by surgeons who hope they have restored to the youth a fully working organ.

The seven-hour operation was performed three weeks ago by a team of Emory University surgeons who peered through powerful microscopes just six hours after the 20-year-old student at a college near Atlanta was allegedly attacked by the estranged husband of a woman he had been seeing.

"That incident has been a trauma to this whole town," a doctor at the college said last week.

"It borders on the barbaric," said one Emory surgean. "You can hardly imagine something like that happening in a civilized society."

But if the attack was barbaric, the treatment ' if it is successful, which may take months to know - could be a triumph. There have been only three successful reimplantations of the severed male sex organ reported in medical history.

Two of the recent successes took place last year, one at Nare Medical University in Japan in June, and the other at Massachusetts General Hospital in Boston in August.

A third apparently successful operation was done last April in Trenton, N.J.

The weapon that was used early in the morning of Thursday, Sept. 15, in the small college town near Atlanta was a butcher knife.

For some time, according to Georgia Bureau of Investigation senior agent Mike Carruthers, a student had been dating the estranged wife of a 24-year-old laborer.

Late on the night of Sept. 14 the laborer allegedly set out with his half-brother - an 18-year-old who looked up to the older brother as a weight-lifter and athlete - in a borrowed truck. The older brother was intoxicated either on drugs or alcohol, and carried a pistol and the knife, Carruthers said.

The two reached the student's apartment.They entered an open back door. They found a roommate there, too.

It was now just after midnight. The younger brother allegedly held the gun on the roommate while the laborer went into the bedroom where the student was studying, chocked him unconscious, tied him hand and foot, then performed the crude surgery.

According to the police, the brothers then chocked the roommate, too into unconsciousness, and they left. The injured student awoke, managed to untie himself, clasped towels to his would to stanch bleeding and awakened his roommate who drove him to the college infirmary.

Both the student and the amputated organ were soon at a larger hospital 20 miles away. A urologist there phoned his friend, Dr. David O'Brien, a urologic surgeon at Emory University, to say he was speeding the young man and served organ - now carefully wrapped and chilled - to Emory.

O'Brien called Emory plastic surgeon Luis Vasconez, a native Ecuadorian who had adopted the new microtechniques for the many delicate reassemblies that plastic surgeons must do.

O'Brien was doing another operation that night, a kidney transplant. But he found time to scan the recent literature on penile transplants.

Vasconez also had read the recent articles. "It was fortunate" he says. "And the boy had a two-hour trip here. So we had time to plan." The patient arrived at Emory Hospital at 5:30 a.m. By 6:15 he was in the operating room. He was conscious and calm and, while he had lost some blood, he was in generally good condition. There was not need to hurry, and time for careful preparation.

The attacker's knife had been sharp, so the cut was clean, which meant that at least some of the internal parts could be seen.

Because of the nature of the cut, they were seen in cross-section, as in an anatomical drawing. And the surgeons' job was to, in effect, complete the drawing - to probe, find and then try to rejoin the finer structures.

This drawing together would progress, and more and more of the two flat ends would be rejoined as the operation continued.

Vasconez worked very slowly. Hours were passing. It was already mid-morning. The sewing of veins and arteries. Some just under four one-hundreds of an inch across, was pains-taking and tedious and the strain sometimes great. O'Brien and Vasconez and four assistants traded tasks back and forth.

Six surgeons in all did parts of the work as the morning progressed. There were also two anesthesiologists and four or five nurses at various times.

At 1:15 p.m. the operation was completed.

The patient - still calm, still bearing up as well as any human being could under the circumstances, the doctors say ' is still urinating through a catheter in the healing urethra and another catheler in his lower abdomen.

"All we can say is that the procedure has been successful so far," O'Brien sums up. There is a good chance, the doctor said, that he will be sexually competent.

The other main characters in the drama - the two half-brothers who allegedly entered the student's apartment ' were arrested on Sept. 21 and charged with breaking and entering, assault and battery with intent to kill, assault and battery of a high and aggravated nature and mayhem.

Police say that three days before they were arrested the older brother - the one who did the cutting - had phoned his younger brother to tell him to return the borrowed pistol they had allegedly used in the crime.

Then, according to Agent Carruthers, "He told the younger brother he loved him and, sounding strangely, that he'd see him 'later.'

"The younger brother got upset at this remark and went to their apartment, which was brand new but bare of furniture. He found his brother in a comatose state on a mattress, all he had for a bed, with pill bottles and a syringe next to him.

"He had pictures of his wife and baby and a Bible around him. And articles of his baby's clothing, like a little baseball cap. And cards his wife had given him on his birthday.

"He was taken to a hospital and survived."