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.
Study design: 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.
Conclusion: 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.