Successful Sonographically Guided Laser Ablation of a Large Acardiac Twin at 26 Weeks' Gestation

Abstract

A cardiac twinning, also known as the reversed arterial perfusion sequence, is a unique complication of monochorionic placentation occurring in 1% of monozygotic twins and 1 per every 35,000 pregnancies. 1 In this condition, the structurally normal twin provides blood supply to the parasitic acardiac twin in a retrograde, paradoxical fashion through a single superficial artery-to-artery anastomosis. 2 In many cases, the continuous growth of the acardiac twin and the associated vascular steal phenomenon may lead to cardiac insufficiency and polyhydramnios in the pump twin. 3 In such cases, intrauterine treatment to interrupt blood flow to the acardiac twin could be the only way to prevent perinatal death of the pump twin. 4 , 5 Percutaneous sonographically guided laser coagulation of the intra-abdominal vessels (ie, the intra-abdominal segment of the single umbilical artery, the intrapelvic vessels, and the abdominal aorta) has been reported as an effective, minimally invasive method to ablate acardiac twins, but the few reported cases to date have been carried out in early pregnancy, during which the size of the acardiac twins is relatively small. 6 , 7 In this report, we describe the use of this technique in the management of a twin pregnancy complicated by a large acardiac twin at 26 weeks' gestation.