Percutaneous ultrasonographically guided ablation of an acardiac twin.

Acardiac twinning is caused by twin reversed arterial perfusion (TRAP). Normal "pump" twins may face early delivery and cardiac decompensation and have a high perinatal mortality. A primagravid patient had serial evaluation of a TRAP pregnancy beginning early in the second trimester. Rapid growth of the acardiac sibling, high diastolic velocity Doppler waveforms in the perfusing vessel, and early hydramnios prompted ablation of blood flow by a percutaneous ultrasonographically guided infusion of absolute alcohol. A term birth of a normal pump twin was the outcome. Ablation of blood flow into an acardiac sibling of a TRAP pregnancy may be indicated in cases with a poor prognosis by use of an effective percutaneous ultrasonographically guided technique.