7: Radiofrequency ablation for twin-reversed arterial perfusion E: The North American Fetal Treatment Network (NAFTNET) experience


      Significant mortality occurs with Twin-Reversed Arterial Perfusion (TRAP) sequence due to a high output state in the normal or “pump” twin as well as return of doubly-deoxygenated blood. Multiple strategies have been used to stop flow in the acardiac mass to prevent complications. Radiofrequency ablation is a minimally invasive method for treatment of TRAP sequence. We report a case series of 83 patients undergoing radiofrequency ablation of the acardiac mass for the treatment of TRAP sequence.

      Study Design

      A multi-institutional restrospective review was performed of all cases from ten member institutions of the North American Fetal Treatment Network. Maternal variables included surgical complications and length of hospital stay. Prenatal variables included size of the acardiac fetus, IUFD, and amnionicity. Postnatal outcome variables included gestational age at delivery and survival to one month of age.


      There were two instances of postoperative failure with persistence of flow to the acardiac twin. Length of stay after the RFA was 1.19 +/− 0.76 days. The mean size of the acardiac mass was 103 +/− 73% that of the normal twin. There were 9 pump twin IUFD's. Overall newborn survival to one month for pump twins was 81% overall (67/83). Survival in monochorionic/diamniotic twin pregnancies was 85% (58/68) with an average gestational age at delivery of 34.5 weeks; for monochorionic/monoamniotic twin pregnancies was 33% (2/6) with an average gestational age of delivery at 26.7 weeks; and for triplet pregnancies with a monochoronic, diamniotic pair, 78% (7/9) with an average age at delivery of 31.3 weeks.


      This is the largest reported series of patients treated with TRAP sequence. RFA of the acardiac mass is an effective, minimally invasive treatment for TRAP sequence with improved results compared to previously published series using other techniques. Additional monochorionic/monoamniotic cases are needed to better define outcomes.