Fetoscopic Nd:YAG laser coagulation for twin-twin transfusion syndrome in cases of anterior placenta

Laser coagulation of anastomosing placental chorionic plate vessels was suggested as a treatment of severe twin-twin transfusion syndrome in midtrimester. An anteriorly located placenta may hamper access and visualization of the vessels involved. We treated six women with completely anterior placenta at 18 to 22 weeks' gestation. Through a 2- to 3-cm minilaparotomy the uterus was accessed after retraction of the viscera. A flexible cannula was inserted through the uterine fundus, and a 35-degree, 0.20-mm minifibroscope and 400-mm fiber were introduced. All vessels crossing the intertwining membrane were coagulated in a continuous mode and a maximum output of 45 W. All fetuses survived the operation. One fetus died in utero 6 weeks postoperatively from cardiac failure, and its receptor twin was born alive. All other pregnancies are either continuing, or the women delivered two healthy babies. Thus far, total fetal survival is 91.6%, compared with results with posterior-sided placentas. Neodymium:yttrium-aluminum-garnet laser coagulation is also possible in case of anterior placenta, but requires a minimal maternal incision and general anesthesia to allow safe cannula placement. A bent scope allows for a larger placental surface to be treated.