title: Selective reduction of acardiac twin by radiofrequency ablation.
abstract: OBJECTIVE
  Acardiac/acephalic twinning is a rare anomaly in which a normal "pump" twin perfuses an acardiac twin, which results in twin reversed arterial perfusion sequence. A novel technique for selective reduction and obliteration of blood flow in the acardiac twin is described.
  
  
  METHODS
  Thirteen consecutive cases of monochorionic twin gestation with twin reversed arterial perfusion sequence underwent selective reduction of the abnormal twin with the use of radiofrequency ablation. Under direct real-time sonographic guidance, a 3-mm (14-gauge) radiofrequency ablation needle was percutaneously inserted through the maternal abdominal wall into the intrauterine fetal abdomen at the level of the cord insertion site of the acardiac twin. Energy was applied until termination of blood flow to the acardiac fetus was documented by Doppler ultrasound scanning.
  
  
  RESULTS
  All 13 mothers tolerated the procedure without major complications. All 13 "pump" fetuses have been delivered. Twelve of 13 infants are alive and well. The first patient in this series was delivered at 24.4 weeks and the infant subsequently died from complications of prematurity. Average gestational age at intervention was 20.7 weeks, and the average gestational age at delivery was 36.2 weeks.
  
  
  CONCLUSIONS
  Radiofrequency ablation is a minimally invasive, percutaneous technique that can effectively obliterate blood supply to an acardiac twin to preserve and protect the pump twin.
authors.affiliation: Fetal Treatment Center, Department of Surgery, University of California, San Francisco 94143-0570, USA.
authors.forename: KuoJen
authors.initials: K
authors.lastname: Tsao
authors.forename: Vickie A
authors.initials: VA
authors.lastname: Feldstein
authors.forename: Craig T
authors.initials: CT
authors.lastname: Albanese
authors.forename: Per L
authors.initials: PL
authors.lastname: Sandberg
authors.forename: Hanmin
authors.initials: H
authors.lastname: Lee
authors.forename: Michael R
authors.initials: MR
authors.lastname: Harrison
authors.forename: Diana L
authors.initials: DL
authors.lastname: Farmer
mesh_terms: D000328:Adult; D017115:Catheter Ablation / Q000379:methods*; D004200:Diseases in Twins; D005260:Female; D005315:Fetal Diseases / Q000601:surgery*; D006330:Heart Defects, Congenital; D006801:Humans; D011247:Pregnancy; D018607:Pregnancy Reduction, Multifetal / Q000379:methods*