title: Radiofrequency driven cord occlusion for selective termination of pregnancy: evaluation in the fetal sheep.
abstract: OBJECTIVE
  This study was designed to assess the ability of an ultrasound-guided radiofrequency (RF)-driven procedure to induce complete and irreversible cord occlusion using a 90 days fetal sheep model.
  
  
  METHODS
  Twenty 90 days gestation sheep underwent general anesthesia. The first ten fetuses were exposed under hysterotomy, and RF electrode was inserted visually in the middle of the umbilical cord and deployed. Fetuses were then replaced into the amniotic fluid and RF procedure (average target temperature of 100 degrees C during 10 minutes) was applied. For the next ten fetuses, RF electrode was inserted into the cords under trans-parietal ultrasound guidance and the same RF procedure was applied. Cord occlusion was assessed by Doppler examination (absence of cordonal flows at the end of the procedure and until fetal heart failure occurred) and by subsequent histopathological analysis.
  
  
  RESULTS
  Cord occlusion was always complete at Doppler examination at the end of RF procedure for the ten experiments realized under hysterotomy. No cordonal reperfusion was observed until fetal heart failure. Histopathological analysis confirmed cordonal occlusion at the site of impact. Neither cordonal rupture nor cordonal bleeding was observed for any of the ten experiments. When RF electrode was inserted under ultrasound guidance, complete occlusion could be obtained only for 6 of the ten experiments.
  
  
  CONCLUSIONS
  Our results suggest that RF might be an appropriate method for selective termination of pregnancy. Yet, optimal insertion of the electrode is required to engender a complete and irreversible cord occlusion, and ultrasound-guidance training seems necessary before current human application.
authors: Department of Obstetrics and Gynecology, Hôpital Lariboisière, APHP, Paris, France. olivier.morel17@wanadoo.fr
authors: Olivier
authors: O
authors: Morel
authors: Nguyen
authors: N
authors: Tran
authors: Emmanuel
authors: E
authors: Barranger
authors: Bernard
authors: B
authors: Foliguet
authors: Frédéric
authors: F
authors: Marchal
authors: Sylvie
authors: S
authors: Chastant-Maillard
authors: Philippe
authors: P
authors: Judlin
authors: Jean-Pierre
authors: JP
authors: Villemot
authors: Olivier
authors: O
authors: Thiebaugeorges
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005333:Fetus / Q000098:blood supply; D017078:Laser-Doppler Flowmetry; D023421:Models, Animal; D011247:Pregnancy; D018607:Pregnancy Reduction, Multifetal / Q000379:methods*; D012756:Sheep; D018084:Ultrasonography, Interventional / Q000379:methods; D014470:Umbilical Cord / Q000000981:diagnostic imaging / Q000502:physiology / Q000601:surgery*