title: New fluorescence endoscope for use in twin-twin transfusion syndrome: in vivo visualization of placental blood vessels.
abstract: Twin-twin transfusion syndrome (TTTS) is a condition in which twins share blood disproportionately by the communicating vessels in the shared placenta, resulting in high fetal and perinatal mortality. Fetoscopic laser photocoagulation is performed to interrupt these communicating vessels; however, small vessels are often missed due to the poor image obtained with a fetoscope. We have developed a fluorescence endoscope capable of visualizing very small vessels, even in amniotic fluid, and we investigated its feasibility for in vivo visualization of placental vessels. Indocyanine green (ICG) was given at single doses of 0.5, 1.0, and 1.5 mg/kg, respectively, into the maternal circulation of pregnant rabbits, and the endoscope was used to identify the placental vessels. The vessels were detected within 15s after ICG injection for about 10 min. The brightness difference between the intervillous space and the umbilical vessels was significantly smaller after administration of 0.5 mg/kg than after 1.0 mg/kg (p=0.02) or 1.5 mg/kg (p=0.01). Even very small vessels (0.2mm in diameter) were detected. In conclusion, our new endoscope successfully provided a detailed view of the placental vessels in vivo. The results are promising for future TTTS laser surgery.
authors.affiliation: Clinical Research Center, National Center for Child Health and Development, Tokyo, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Ishiyama
authors.forename: Keri
authors.initials: K
authors.lastname: Kim
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Yamashita
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: Shin
authors.initials: S
authors.lastname: Enosawa
authors.forename: Toshio
authors.initials: T
authors.lastname: Chiba
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000378:metabolism*; D004724:Endoscopy / Q000379:methods*; D005260:Female; D005330:Fetofetal Transfusion / Q000378:metabolism / Q000503:physiopathology; D007208:Indocyanine Green / Q000378:metabolism; D010920:Placenta / Q000098:blood supply*; D011247:Pregnancy; D011817:Rabbits; D013050:Spectrometry, Fluorescence
chemical_list: D007208:Indocyanine Green