Clinical trial holds hope for pediatric organ transplant patients

It is a medical Catch-22; the nutritional supplement necessary to keep children with failing intestines alive also can damage another vital organ.

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David Mercer, M.D., Ph.D.
"Children with short intestines have a very difficult time absorbing sufficient nutrition by mouth to survive and grow," said David Mercer, M.D., Ph.D., assistant professor of surgery-transplant at UNMC and director of the Intestinal Rehabilitation Program at The Nebraska Medical Center. "In order to get sufficient calories to grow, they require intravenous feeding called total parenteral nutrition (TPN)."

The calorie-dense lipids in TPN help keep the intestinal failure patients alive, but the type used in the United States contain a high amount of Omega-6 fatty acids, which can lead to cirrhosis of the liver.

"The cirrhosis can develop very quickly in children; often in as little as three to six months," Dr. Mercer said. "Without a major medical intervention or a transplant, these children die."

Dr. Mercer is hopeful about a new clinical trial that just began at The Nebraska Medical Center. Omegaven, a lipid preparation made from fish oil, could be far less toxic to patients' livers than TPN.

"It may even reverse damage done to the liver by other kinds of lipids," Dr. Mercer said.

Trial important to hospital's renowned program

The Nebraska Medical Center's pediatric intestinal failure program is the busiest in the world. The intestinal transplant program is the largest in the United States.

"That experience allows us to comprehensively treat patients like Braxton," Dr. Mercer said. "It's why this trial is so important; we can now enroll patients in this study which will allow them to have access to Omegaven in a controlled setting with comprehensive medical and surgical care of their intestinal failure."

Seven-month-old Braxton Anderson of Alda, Neb., is lucky; TPN has been his sole source of nutrition since birth.

"His liver is OK for now," said Braxton's mother, Cassie Hendrickson. "But we're really looking forward to the start of the Omegaven trial - anything to save his liver."

Born with gastroschisis, an intestinal defect, Braxton lost the majority of his small intestine right after he was born.

"He only has 47 centimeters of small intestine," Hendrickson said. "He doesn't know how to eat by mouth, he's been fed by his TPN line his whole life."

"Even so, he seems like a normal baby," said TR Anderson, Braxton's father. "He loves to watch people and always smiles when we put on country music."

His parents hope the medical center's Intestinal Rehabilitation Program can help Braxton lead a more normal life while minimizing the need for more surgery. Part of that is Omegaven. With it, Braxton may be able to receive his nutrition without damaging his liver, all while doctors work to repair his intestines.

Big player

The Omegaven clinical trial in Omaha is among the largest of its kind in the world.

Omegaven, a lipid preparation made from fish oil, could be far less toxic to patients' livers than intravenous feeding, or total parenteral nutrition (TPN).

Currently, Omegaven is only available in Europe, except in the case of studies like the one in Omaha or under special release from the FDA. Where TPN lipids are made from dense soybean lipids, Omegaven is made from fish oil.

"Fish oil is all Omega-3 fatty acids," Dr. Mercer said. "These are the lipids we always hear about being 'heart healthy.'"

Medical center patients receive it as part of the trial and are under the close watch and care of doctors and nurses in the Intestinal Rehabilitation Program.

Even though Braxton still faces serious and complicated medical issues, his parents feel lucky to be receiving world-class care just a few hours from home.

"We didn't know the intestinal rehab program existed," Hendrickson said. "But we're glad we found it."