They used to call it "going under the knife" -- be it brain surgery or tonsillectomy. Any kind of surgery often was vaguely likened to a death sentence. "Let me tell you about my operation" became the tag line for a whole genre of more or less tasteless comedy routines, just as it was the badge of the heroic survivor.

As surgery has become increasingly sophisticated, with computerized, laser-ray space-age technology literally at the skilled fingertips of an army of specialists, many of the fears surrounding the simpler surgical procedures have evaporated.

But just because of the increasing sophistication, there is a whole world of new surgical techniques that, no matter how you (oops) slice it, constitute major violations of an individual's body, never mind how essential to that individual's survival.

No more do most doctors -- as they did even 10 or 15 or 20 years ago -- say to a patient "You need a thus-and-so-ectomy. Be in the hospital tomorrow. Period." There is a growing openness in the doctor-patient relationship that presupposes an individual's readiness to take some responsibility for his or her body.Ther are a lot of new and complicated decisions to be made and the medical community is increasingly eager to share them with the patient.

The major question is, how does the doctor communicate to the patient the information required for an educated decision.

Dr. Paul J. Melluzzo, Georgetown University Medical School assistant professor of surgery, is deeply concerned with this part of the problem.

"People," he says, "have been more and more interested in finding out about the technical aspects of their operation. And they were learning about it through neighbors and friends, over the back fence, as it were. If they asked where they could read about the operation they would find either over-simplified pamphlets or over-technical texts."

Melluzzo, and writer Eleanor Nealon, have just published a book, "Living With Surgery" (Lorenz Press), which, they hope, will give something more to the prospective surgical patient than can be provided either by busy doctor or back-fence pronouncement. In general, says Nealon, "If you know what you're dealing with you can learn to cope with it."

The book is a blend of easily absorbed medical information and interviews with former patients and the families of former patients who have undergone some of today's "major surgical procedures," as the doctors call them with vast understatement. These are mastectomies, ostomies, amputations, hysterectomies, neurosurgery, kidney transplant, surgery for birth defects, open-heart surgery.

Many of these require major changes in the everyday lives of the patients and their families. Sometimes the changes are permanent.

"Attention has been given to the patient," says Melluzzo, "but the immediate family and friends have been neglected . . . and sort of wander aimlessly about, not knowing what to say or when to say it, how to act . . . The medical people, the physicians, the nurses, have a basic fund of knowledge, but . . . when you talk to people, sometimes anxiety interferes with what they hear, or can digest . . . "

Melluzzo and Mealon set about to find out what former patients would have liked to have known before their operations -- the tips, the hints that only somebody who'd been through it before could know.

And to bring out in the open some of the you-want-to-know-but-are-afraid-to-ask-about problems. Like, what does a man or woman with a colostomy (a bag to collect fecal material) do about lovemaking? Answer: Try a cummerbund or drape a negligee. What can you do if it leaks? Face it; it probably will, say ostomates quoted in the book. The first time is the worst, but everybody can minimize the feelings of embarrassment or humiliation and patients who've been through it are only a page away.

Because the intent of the book was to deal with the most common of the biggest operations, and because it carefully sidestepped current medical controversies, the sections on problems of women -- breast cancer treatment and hysterectomies -- although sympathetic and sensitive, may not be fully satisfactory to some women.

However, at Nealon's particular urging, there is discussion of breast reconstruction, for example, and anecdotal material on a patient who chose to have biopsy as a preliminary procedure rather than an instant mastectomy, should such be warranted.

"That," notes Nealon, "was really very avant-garde when we were preparing the book," which was published before the recent report from the National Cancer Institute recommending virtual abandonment of the radical mastectomy as a routine breast cancer treatment.

(For those specifically interested in those aspects of the problem, more detailed information will be available soon from the National Women's Health Network and can be ordered now through its offices at 2025 Eye St. NW).

But that is not the principal function of the Melluzzo-Nealon book. There is a commonality of interests among all patients facing the same surgery, they found, or having to face a family member or friend coming home from the hospital without a limb or with an ostomy, feeling threatened by death, feeling unloveable and terrified a partner will feel the same . . .

"It is so easy after a mastectomy for people to hurt each other," said Nealon, "if a woman misinterprets her husband's fear of hurting her for rejection, for example. These kinds of things really can cause great psychological damage and distancing between couples."

"Not all the endings are happy," Melluzzo said. "Some of the patients quoted -- many were cancer victims -- aren't around any more . . . but even patients with despondent outlooks and for whom death was very close, still had helpful things, some way of adapting or adjusting."

Adds Nealon, "I admit I was astonished how many people came out of the pits of something and said, 'I really learned a lot about it' or, 'I'm a better person for it.' Their resiliency, their courage, their faith and their sense of humor . . . it was fantastic."