Neodymium:yttrium-aluminum-garnet laser occlusion of rhesus placental vasculature via fetoscopy.

We tested the feasibility of photocoagulating placental vascular communications with a fetoscopically delivered neodymium:yttrium-aluminum-garnet laser in 12 pregnant monkeys in the second trimester. The technique was successful in eight cases. One ended in spontaneous labor 2 weeks after occlusion and one stillbirth occurred at term. Six live fetuses were delivered at term, with all treated vessels demonstrating occlusion. There was minimal placental damage at the laser impact sites, and no fetal abnormalities were detected. Long-term occlusion of placental vasculature can be accomplished by fetoscopically delivered laser energy.