Unsuccessful management of acardiac fetus with intrafetal alcohol injection.

Abstract

Twin reversed arterial perfusion (TRAP) sequence is an extreme form of twin-to-twin transfusion in which the normal ‘pump’ twin perfuses its acardiac cotwin. The pump twin has a 50% mortality rate due to congestive heart failure, and polyhydramnios and preterm delivery are further obstetric complications. The risk of an adverse pregnancy outcome is increased when the ratio of acardiac twin : pump twin weight exceeds 70%. Management of TRAP sequence includes elective termination, observation and follow-up using ultrasound or cardiotocography, digoxin therapy for cardiac failure of the pump twin and interventions that target the blood supply of the acardiac fetus. Coagulation of the vascular anastomosis under sonoendoscopic control and percutaneous umbilical cord ligation are invasive therapeutic options. Percutaneous intrafetal alcohol injection has also been reported as a simple and less invasive procedure1, 2. We report here our unsuccessful management using intrafetal alcohol injection of an acardiac acephalic twin pregnancy in a 16-year-old woman, gravida 1 para 0, at 12 weeks of gestation. On admission, ultrasound evaluation demonstrated a monochorionic twin pregnancy in which one of the fetuses had no head and upper extremities but normal mobile lower extremities (Figure 1) and significant edema around the trunk. Despite the absence of the heart, blood flow in the acardiac fetus was demonstrated on Doppler ultrasound examination, which was maintained by the vascular anastomosis between the two fetuses. Ultrasound image of a monochorionic twin pregnancy in which one of the fetuses had no head and upper extremities but normal mobile lower extremities and significant edema around the trunk. The patient was informed about the possible complications and therapies of acardiac twinning and chose conservative follow-up. At 16 weeks of gestation, intrafetal alcohol injection into the acardiac fetus1, 2 was offered. The size ratio of the acardiac twin : pump twin was estimated to be 50%. After obtaining written consent, 8 mL absolute alcohol was injected into the intrafetal part of the umbilical artery of the malformed fetus under direct color Doppler ultrasound guidance and the white-out phenomenon was observed without complication. The blood flow in the acardiac fetus persisted after the procedure. Weekly ultrasound examinations revealed normal growth of the pump twin while the acardiac twin became more edematous but continued to grow as demonstrated by fetal length measurements. At 24 weeks of gestation, the weight ratio of acardiac twin : pump twin was calculated to be 38% according to the published equations3. To prevent possible future complications including heart failure of the normal twin, a second intervention was carried out using 12 mL alcohol injection into the umbilical artery of the growing acardiac twin. Blood flow persisted after the procedure. At 27 weeks of gestation, premature rupture of the membranes occurred. Due to meconium-stained amniotic fluid and persistent late decelerations recorded on fetal cardiac monitoring, Cesarean delivery was performed. The normal twin weighing 800 g had a 5-min Apgar score of 3 and died despite 20 min of resuscitation. The acardiac fetus weighing 300 g was acephalic and had no upper extremities but edematous lower extremities (Figure 2). Inspection of the placenta revealed vascular anastomoses between the two umbilical cords. The postoperative follow-up of the mother was uneventful and she was discharged on the third postoperative day. Postmortem photograph of the acardiac fetus revealing that it was acephalic and had no upper extremities but edematous lower extremities. The prediction of outcome of pregnancies complicated by TRAP sequence is problematic as this is a rare malformation with heterogeneous presentations. The weight ratio of the acardiac twin : pump twin may be important in the prediction of pregnancy outcome, and invasive interventions should be avoided in the presence of a small acardiac mass. Invasive procedures are not free of complications and need a high level of skill, experience and technology. We failed to stop the growth of the acardiac twin despite proper percutaneous intra-umbilical alcohol injection. We suggest that further work is needed to prove the efficacy of this recently advocated technique. S. Ozeren*, E. Caliskan*, A. Corakci*, S. Ozkan*, * Department of Obstetrics Gynecology, Kocaeli University School of Medicine Şehit Ekrem Mahallesi, Bahçekent villaları No. 17, Bahcecik, Izmit, Turkey