Like many Americans, Maureen Como would like to get into better shape, and she thinks she'll need another knee replacement operation.

But in some ways, she's glad to be facing these challenges, because there are many who wouldn't have bet she'd be alive today.

Nineteen years ago, Ms. Como found out that she needed both an intestinal transplant and a liver transplant. Today, the 45-year-old Bethel Park woman is the world's longest survivor of the double procedure.

While the length of her survival is exceptional -- "I'm kind of freaky," she said in her still-distinctive Bronx accent -- Ms. Como is at the apex of a remarkable turnaround in this most challenging of all organ transplants.

A new study by UPMC transplant surgeons shows that over the past 18 years, the five-year survival of intestinal and multi-organ abdominal transplant patients has risen from 40 percent to nearly 70 percent.

While that lags in comparison with some other organ transplant survival rates, it is still remarkable, given the fact that the intestine creates the strongest rejection response of any transplanted organ.

The key to the recent improvements has been finding a way to trick patients' bodies into accepting the transplanted intestinal tissue as their own, said Dr. Kareem Abu-Elmagd, director of the Intestinal Rehabilitation and Transplantation Center at UPMC's Thomas E. Starzl Transplantation Institute and lead author of the study in the October issue of Annals of Surgery.

Doctors now use a biological agent called Campath before a patient gets an intestinal transplant. It depletes the body's two major types of immune system cells and prevents the sharp rejection of transplanted tissue that used to plague this operation in its early days in the late 1980s and early 1990s.

Once a patient's immune system regains full strength after the effects of the Campath wear off, it "doesn't see the donor organ as the enemy but partially as self," and doctors are then able to use lower doses of anti-rejection medication, Dr. Abu-Elmagd said.

The exact mechanisms of this acceptance are still a mystery.

"If I knew the answer to that," he said, "I'd have the Nobel Prize."

The study looked at 500 organ transplants performed on 453 patients at UPMC between 1990 and 2008. In many ways, it charts an overall history of the procedure because UPMC has done a quarter of all intestinal transplants in the world and about 50 percent of all adult intestinal transplants.

The transplants fall into three distinct eras, the study said. In the first period, from 1990-1994, doctors used the anti-rejection medicine Prograf, known generically as tacrolimus, with the steroid prednisone.

While that combination prevented the organs from being rejected, it eventually opened patients up to bacterial and other infections. The survival rate was 40 percent after five years.

In the second era, from 1995 to 2000, UPMC doctors began giving patients some of the donor's bone marrow as well in hopes that would increase acceptance of the new tissue. Five-year survival climbed to 56 percent.

In the past eight years, the study said, they began using Campath and other immune-dampening drugs before the operation, and the survival rates have now climbed to 68 percent.

Dr. Andreas Tzakis, director of liver and gastrointestinal transplants at the University of Miami, introduced the Campath regimen in 2001. In an e-mail interview, he said it has been very important in improving survival rates because it "fundamentally allows a smooth introduction of new tissues." Another key advance, said Dr. Tzakis, who did his early training in Pittsburgh, is that doctors now can monitor a blood marker to detect early rejection of the tissues and adjust medication levels.

Because her surgery occurred in an earlier transplant era, Ms. Como suffered some of the consequences of heavier anti-rejection dosages. Kidney damage is one common side effect of the potent anti-rejection drugs. Four years ago, her kidneys failed, and she had to get a kidney transplant from her brother.

She now takes two doses of anti-rejection medicine each day, part of a 40-pill lineup that includes lots of vitamins and nutritional supplements because her transplanted intestines still don't absorb nutrients efficiently.

Her original medical problems began after she gave birth to her son, who is now 21 and attending Duquesne University.

"I began having sharp pains in my stomach and I was admitted to the hospital twice, but they told me nothing was wrong and sent me home," she said.

After her third trip to the hospital, a surgeon decided to look in her abdomen and discovered that a major artery had been blocked and most of her small intestine had gangrene and had to be removed.

Dr. Debra Sudan, chief of abdominal transplant surgery at Duke University, said there are many reasons why patients need an intestinal transplant. But like Ms. Como, they usually end up having most of their small intestines removed, and once a person is down to 10 percent or less of the normal 10 feet of small bowel, the body can no longer absorb nutrients through normal eating.

Like most such patients, Ms. Como had to go on liquid nutrition. She traveled to Pittsburgh after her own research taught her about the pioneering organ transplants being done by Dr. Thomas Starzl and his colleagues, who included Drs. Abu-Elmagd and Tzakis.

She remembers that Dr. Starzl immediately put her at ease.

"When I first walked into his office, he said 'You look a little green.' 'I am a little green,' I said, and he said, 'You need a liver. But while I'm at it, I'll throw in an intestine, too.' His sense of humor really made a difference for me."

She got both organs in a 16-hour operation in August 1990. It took her a full year to recover, complicated by the fact that she developed aneurysms in her legs that had to be surgically repaired.

Until then a lifelong New Yorker, she relocated to Pittsburgh permanently to be near Dr. Abu-Elmagd and her other transplant physicians and nurses.

Because more and more patients are living extended lives after abdominal transplants, Dr. Sudan said it may be possible within the next five years to consider these surgeries as a first-line treatment for intestinal failure, rather than starting patients on the liquid nutrition.

"I think these surgeries will continue to grow," she said. "As we get better immune regimens and we have less rejection and less infection, it will allow for better patient survival."

For Maureen Como, life is full of hope.

"I feel pretty good for all I've been through," she said. "I don't regret it, and if I had to do it again, I would."

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