Mini tools for mini patients.

For the first time, surgeons report successfully performing an operation in the womb using needle-size surgical instruments, including a tiny endoscope that makes possible video imaging of the inside of the amniotic cavity.

"We think perhaps this is... a new frontier in perinatal medicine," says surgeon Ruben A. Quintero of Hutzel Hospital at Wayne State University in Detroit. This procedure makes letuses "true surgical patients" and may one day be used to repair birth defects, he asserts.

"The potential for this is enormous," agrees Steven Klein of the National Institute of Child Health and Human Development in Bethesda, Md.

Quintero and his colleagues performed the procedure, called operative fetoscopy, to tie a knot in the umbilical cord of an 18-week-old fetus that lacked a brain and heart and jeopardized the life of its healthy twin, they write in the Feb. 17 NEW ENGLAND JOURNAL OF MEDICINE.

The physicians used an instrument with miniature scissors and a grasper to tie the knot, he says. The letoscope, an endoscope for fetal surgery, and ultrasound guided the surgeons. Quintero has since successfully repeated the procedure, he says.