title: Efficacy of radiofrequency ablation for twin-reversed arterial perfusion sequence.
abstract: OBJECTIVE
  We report our experience in the treatment of patients with twin-reversed arterial perfusion (TRAP) sequence using radiofrequency ablation to stop perfusion to the acardiac twin and protect the pump twin.
  
  
  METHODS
  An IRB approved retrospective review of all patients (n = 29) who underwent percutaneous radiofrequency ablation of an acardiac twin, using ultrasound guidance and either a 14 or 17 gauge radiofrequency needle for twin-reversed arterial perfusion sequence, from 1998 to 2005, was performed by review of hospital and outpatient medical records.
  
  
  RESULTS
  The outcomes of all 29 of the patients treated with radiofrequency ablation are known. Twenty-six of the patients had monochorionic-diamniotic pregnancies, whereas 2 had monochorionic-monoamniotic pregnancies. One patient had a triplet pregnancy with a monochorionic-diamniotic pair with TRAP sequence. Overall, 25 of 29 pump twins survived (86%), delivering at a mean gestational age of 34.6 weeks. Survival was 24 of 26 (92%) in monochorionic-diamniotic pregnancies with a mean gestational age of 35.6 weeks. Two women in our early experience sustained thermal injuries from the site of grounding pads.
  
  
  CONCLUSIONS
  Radiofrequency ablation of the acardiac twin effectively protects the pump twin from high-output cardiac failure and death. Greater than 90% survival can be achieved in monochorionic-diamniotic pregnancies complicated by TRAP sequence with a mean gestation age at time of delivery close to term. Our limited experience in cases of monochorionic-monoamniotic TRAP sequence does not allow the determination of efficacy in this group.
authors.affiliation: Fetal Treatment Center and the Department of Surgery, University of California, San Francisco, San Francisco, CA 94143-0570, USA. leeh@surgery.ucsf.edu
authors.forename: Hanmin
authors.initials: H
authors.lastname: Lee
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Wagner
authors.forename: Edgar
authors.initials: E
authors.lastname: Sy
authors.forename: Robert
authors.initials: R
authors.lastname: Ball
authors.forename: Vickie A
authors.initials: VA
authors.lastname: Feldstein
authors.forename: Ruth B
authors.initials: RB
authors.lastname: Goldstein
authors.forename: Diana L
authors.initials: DL
authors.lastname: Farmer
mesh_terms: D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D005315:Fetal Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D005318:Fetal Heart / Q000002:abnormalities; D005330:Fetofetal Transfusion / Q000000981:diagnostic imaging / Q000601:surgery*; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging / Q000601:surgery*; D006801:Humans; D011247:Pregnancy; D018607:Pregnancy Reduction, Multifetal / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome; D014310:Triplets; D016216:Ultrasonography, Prenatal