Article-New technology is transforming the delicate...

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New technology is transforming the delicate - and controversial - process of harvesting livers from living donors

By , Globe Staff, 9/2/2003

It is among the most unsettling propositions known to medicine: Is saving a failing life worth risking a healthy life? McKeehan Murray knew in her heart there was just one answer. Of course she would sacrifice a chunk of her liver to replace the diseased organ inside her husband, whose mind had turned foggy and whose belly had grown bloated as his liver deteriorated.

A computer screen full of glowing and twirling colors proved that she could indeed save her husband's life without unduly risking her own. The three-dimensional image of McKeehan Murray's liver was rendered in such crystalline detail that surgeons had a road map on which they could trace every vein, every artery, and even calibrate the effect of vessels on specific neighborhoods of the organ.

"It's kind of like color by number: Just connect all the dots, and we'll all be fine at the end," said McKeehan Murray, who lives with her husband Murray in Mendon. "Having the data right there in front of you and seeing that it was a match, I knew that we had a really good chance of it working."

McKeehan Murray and her husband stand at the vanguard of an advance in medical technology that holds the promise of improving the safety of one of the most challenging operations ever to be performed in a surgical suite, a living donor liver transplant. Lahey Clinic, the Burlington hospital where part of the wife's liver was transplanted into her husband, is the first in the nation to have in-house use of German software that converts routine images gleaned from scanning machines into 3-D depictions that even guide surgeons on where to cut.

The need has never been greater, with more than 17,000 patients lingering on waiting lists for livers from the deceased. Live donors provide an alternative organ source, but the operations have faced stringent reviews in the wake of a donor's death last year at a prestigious New York hospital that had performed more of the procedures than any other medical center in the nation.

"We have a crisis of not having enough organs available for the people who need them," said Dr. Pomfret, director of live donor liver transplantation at Lahey Clinic. "That has been the impetus for moving into an area that is extremely controversial -- using an otherwise healthy person as a liver donor for another person."

On its face, the notion of subjecting an otherwise robust person to potentially life-threatening surgery would appear to violate the most sacred maxim of medicine: First, do no harm.

But with so many profoundly ill patients pursuing so few livers from cadavers, there is little prospect that donors, recipients, or surgeons will shrink away from the operation, even if estimates show that up to one percent of donors die from the surgery.

"It won't go away because it's been shown to be feasible," said Dr. C. Cronin, a University of Chicago surgeon who performs liver transplants. "And it won't go away because there's a need."

That need is only going to grow in coming years. An estimated 4 million Americans suffer from hepatitis C, a sometimes lethal liver ailment that can lie dormant for decades before it begins attacking. Specialists believe a significant share of the nation's hepatitis C patients were exposed in the 1960s and 1970s, an era when less rigorous screening of the blood supply and widespread sharing of drug needles allowed the virus to spread.

Now, in middle age, those patients are experiencing the arrival of severe illness sometimes cured only with a new liver. And each year, several hundred of them will get that organ from a relative or friend, testament both to the generosity of the donor as well as the liver's remarkable ability to regenerate, permitting surgeons to lop off roughly three-fifths of a healthy patient's liver and transplant it in an ill patient.

"Especially in such a live donor transplant, we are focused on doing no harm to the donor," said Dr. Klein, chief of the division of transplantation at the s Hopkins Hospital in Baltimore. "The donor derives no tangible benefit from being a donor. The only benefit they derive is the satisfaction from helping someone else."

Ensuring a successful live donor transplant is complex because the liver is so exquisitely intricate.

"The liver is a big factory inside the body," said Dr. Christoph Wald, director of Advanced Image Analysis and Virtual Surgical Planning at Lahey. "It is a very complicated system of tubes, and they're all intertwined."

And there's no template. Livers are as singular as fingerprints, with different people having different configurations of vessels that perform the plumbing functions of the liver.

That's why having a road map of a potential donor's liver is so vital. That map can help doctors determine who will be a suitable donor and who will not.

"We can never make the risk zero for the donor, but clearly, the whole focus of the preoperative evaluation is to make the risks to donors as close to zero as possible," Lahey's Pomfret said.

In the past, radiologists and surgeons relied on two-dimensional or early three-dimensional images to evaluate the anatomical architecture of a donor's liver. While those images were helpful, there was much they did not show. For example, veins leaving the liver are responsible for draining specific regions of the organ. With older technology, doctors did not have precise measurements of how much of the liver was drained by a particular vein, making it difficult to judge the importance of preserving it during the operation.

The new 3-D technology changes all of that.

"That knowledge is key to the surgeon because now you can predict the consequences of cutting through certain blood vessels during the operation," Wald said. "Therefore, you can better plan the surgery."

The 3-D images are the result of CT scans converted by a software designed by a German research institute called MeVis and requiring the collaboration of a mathematician, radiologist, computer scientist, and surgeons.

The HepaVision2 system they developed provides color coordination showing doctors, for instance, that a vein rendered in a deep shade of salmon is responsible for draining an identically hued swath of the liver. It even calculates the precise volume of liver drained by that vein.

With those data, surgeons can then determine which veins they will connect in the recipient and which they will simply tie off. Such decisions are crucial to minimizing exploratory surgery, reducing time in the operating room, and, consequently, lowering the risk of complications.

"With living donors," said Dr. s Tzakis, a University of Miami transplant surgeon, "it's very delicate surgery, the differences are small, millimeters mean a lot. So knowing the exact three-dimensional anatomy is extremely advantageous."

Tzakis is among the transplant luminaries hoping to get their hands on the 3-D capabilities introduced to the United States through Lahey's relationship with the German researchers. Cronin, of the University of Chicago, harbors that same enthusiasm -- but with a caveat. Any imaging technology, he said, relies on capturing minute slices of the patient's body and then recombining those small slices to make a whole.

"You always have to be cautious with any image of this sort -- sometimes, some things are missed and some things are over-read," Cronin said. "It's not like holding the liver in your hand, but it's probably as good as you're going to get without holding the liver in your hands."

For McKeehan Murray, an emergency room nurse-practitioner, the 3-D image sufficed. Her husband was diagnosed nearly a decade ago with hepatitis C, apparently acquired through a tainted blood transfusion. By August of last year, his liver had begun to fail.

"Knowing what I know, I said, `My husband is dying in front of me,' " McKeehan Murray said. "Dying from liver disease is a horrifying death. I said, `I would rather die than have this happen to my husband.' "

In an earlier era, doctors might well have rejected her. After all, she's substantially smaller in stature than her husband, and certain quirks in the anatomy of her liver might have suggested it was less than ideal for transplantation.

But by using the new 3-D technology, doctors realized McKeehan Murray's liver stood a fine chance of saving her husband's life.

The surgery was performed Feb. 10 at Lahey. Within a week, the piece of McKeehan Murray's liver transplanted in her husband -- it represented about 60 percent of her total liver -- had grown to full size inside him.

What remained of her liver began regenerating as well, and within 10 weeks she was back at work.

Now, nearly seven months after the transplant, McKeehan Murray, 45, has resumed life like before the operation. Murray, 54, has endured a series of complications but continues to recover.

"So," McKeehan Murray said, "we're kind of joined at the liver now."

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