ICG fluorescence endoscope for visualization of the placental vascular network.

Intrauterine laser photocoagulation for twin-twin transfusion syndrome (TTTS) needs accurate in-situ recognition of placental vascular anastomosis. Because the conventional procedure is highly dependent upon the operators' skill and experience, we developed a new way to visualize the placental vascular network by a rigid-type fluorescence endoscope coupled with intravenous administration of Indocyanine green (ICG). The feasibility of the fluorescence endoscope was examined with monkey placentas and pregnant rats. The ICG fluorescence endoscope can visualize the placental vascular network in detail even in the presence of turbid amniotic fluid. Thus, this method is potentially useful for in-situ definition of the placental vascular anastomoses during the treatment for TTTS. In addition, our rigid-type fluorescence endoscope will also be a useful tool for lymph node dissection using ICG by endoscopic surgery.