FETAL SURGERY: MIRACLE BEFORE BIRTH
PROCEDURES DONE IN THE WOMB BOTH AMAZE AND RAISE MANY QUESTIONS

`Closed' procedures are the future
Although ``open'' fetal surgery is dramatic, doctors are increasingly turning toward ``closed'' or minimally invasive procedures in which thin instruments and a small TV camera are inserted through tiny incisions; sometimes they use ultrasound to guide needles to insert shunts.
At New England Medical Center, Wendy Andrasy, 33, a Weymouth police officer, has already reaped the benefits of this approach.
When she was pregnant two and a half years ago, her fetus had an enlarged bladder, a sign that something was obstructing the flow of fetal urine into the amniotic fluid. This can cause kidney damage as urine backs up; it can also sabotage lung development.
Fetal urine contains a growth factor that is ``essential for lung development,'' says Dr. Diana Bianchi, chief of genetics at the Floating Hospital for Children at New England Medical Center. Normally, the fetus ``is inhaling its urine and that is allowing this growth factor to get to the lungs.''
But Andrasy's fetus wasn't getting that growth factor. So when she was 20 weeks pregnant, Dr. Sabrina Craigo, a perinatologist at NEMC, slipped a tube through Andrasy's uterus, using ultrasound guidance, and placed a drainage shunt with one end in the fetal bladder and the other in the amniotic sac.
At the University of California in San Francisco, Dr. Michael Harrison, director of the fetal treatment center and the undisputed leader in fetal surgery, is pushing the envelope even further.
Harrison notes that 1 in 2,000 babies is born with a diaphragmatic hernia, a hole in the diaphragm that allows the intestines and sometimes the liver to poke up into the chest cavity. When this happens, the lungs get so compressed they never develop, which means that as soon as the baby is born, it dies.
The solution is counterintuitive: occlude the fetal windpipe. Fetal lungs make fluid that pours into the airway and out of the mouth; by blocking this outflow, the fluid, which spurs lung growth, is pumped back into the lungs.
Harrison's team has perfected a way to close the fetal windpipe endoscopically with a clip that is placed on the fetal trachea during surgery and left there for the remainder of the pregnancy. It is then removed during delivery by C-section so the baby can breathe normally. The results on the first dozen patients, not yet published, suggest that it works much of the time, he says. At Children's Hospital in Boston, Dr. Rusty Jennings , director of fetal diagnosis and treatment, is gearing up to do the trachea procedure, as well surgery for spina bifida and other problems.
At a number of hospitals nationwide, including New England Medical Center and Hasbro Children's Hospital in Providence, doctors are working on ways to use endoscopes and lasers to treat yet another fetal abnormality, the mixing of blood between identical twins whose blood vessels join in the placenta. When this happens, says Dr. Francois Luks, associate professor of surgery and pediatrics at Brown University, one twin's heart tries to pump blood for both, causing heart failure; the other twin often dies from anemia because it gets too little blood.
As for Andrasy, her son was born two years ago. The surgery prevented the child's death from underdeveloped lungs, but was not able to prevent kidney damage -- in fact, he needs a kidney transplant. But Andrasy, now pregnant again, was thrilled: ``He's wonderful. They saved his life. He's funny. He's a great kid. He smiles all the time.''