Fetal Surgeries of the Future

[Angel]

Does type 1 diabetes start in the womb as an accident of biology? And more importantly, can it be prevented? This is one of the many questions a leader in the field of fetal surgery says could be answered in the near future and could lead to new treatments.

Surgeon Michael Harrison, M.D., tells Ivanhoe treating the patient even before they are born could prevent some adult diseases, like diabetes or sickle cell anemia. Dr. Harrison is world-renowned for his work in fetal medicine. He established the Fetal Treatment Center at the Children's Hospital at the University of San Francisco, the first center of its kind in the United States. Twenty-five years ago, he performed the first successful surgery for urinary tract obstruction on a fetus.

Fetal surgery is usually only resorted to when it's the only chance of survival. Conditions like urinary obstruction and diaphragmatic hernia often kill the baby. However, there is scant evidence that procedures done in the womb, which often lead to premature birth, offer any benefit over performing the same procedure after the child is born.

Dr. Harrison is now part of a multi-center, randomized trial comparing repair of spina bifida lesions in the womb to waiting until after the child is born to make the repair.

Spina bifida is a birth defect caused by not enough folic acid in a mother's system during a critical early development stage of the fetus. The defect, an opening along the spinal cord, exposes the delicate nerve fibers to amniotic fluid and often leads to paralysis and fluid on the brain. Doctors theorize that closing the hole and protecting the spinal cord may help prevent some of the problems children with spina bifida experience. Previous experience has shown the procedure will not always prevent paralysis, but it may decrease the risk of hydrocephalus. "The question is, is it true that it does that, and the second issue is, is that enough of an advantage to counter balance the risk of open fetal surgery and the risk to the mother. It's quite interesting," Dr. Harrison told Ivanhoe.

Dr. Harrison excitedly explained to large crowd of surgeons at the American College of Surgeons 2006 Clinical Congress in Chicago that there are many more discoveries to make in this field. He brought up the possibility of stem cell transplants done before a fetus has developed the ability to reject foreign DNA. The fetus would take on the new stem cells as its own, becoming a chimera -- someone with two sets of DNA controlling their biology. Fetuses determined to have sickle cell anemia, caused by defective blood-making stem cells, could be given brand new stem cells just a few months after conception.

"By fooling around in the fetal environment you have lots of advantages, immunologic advantages like tolerance because you can take advantage of the fetus's own process of self recognition, and maybe you can beat the rejection response," Dr. Harrison said. Any treatment like this is still many years away from being a reality.

Continued research in fetal medicine may also solve the problem of scarring. Not just a cosmetic problem, scar tissue can cause a variety of medical problems by constricting the normal processes of the body. It's been noted that when procedures are done early enough on a fetus, there is no scarring. "The knowledge that you get from how the fetus does it so cleverly is going to be very important for adult problems," Dr. Harrison said.

SOURCE: Ivanhoe interview with Michael R. Harrison, M.D., University of Southern California, San Francisco, at the American College of Surgeons 2006 Clinical Congress in Chicago, Oct. 8-12, 2006