Twin reversed arterial perfusion sequence-a rare and dangerous complication form of monochorionic twins:A case report

BACKGROUND Twin reversed arterial perfusion(TRAP) sequence is an extremely rare congenital anomaly in monochorionic(MC) twins.The condition is characterized by a malformed fetus(acardiac twin) without cardiac activities being perfused by a structurally normal one(pump twin) via an artery-to-artery anastomosis in a reverse direction.CASE SUMMARY We described the first case of TRAP to receive laser surgery in Vietnam.The 26-wk pregnancy was originally misdiagnosed in another hospital as MC twins with single intrauterine fetal death.Following admission to our center,the diagnosis was amended to a 26-wk TRAP sequence stage IIb.The acardiac twin was 7.5 cm at the longest length,the ratio of the weight of the acardiac twin to the weight of the pump twin was more than 90%,the pump twin showed fetal distress with absent diastolic flow in umbilical artery of pump twin,and the peak systolic velocity in the middle cerebral artery = 1.6 Mo M.We performed emergency laser photocoagulation of the acardiac twin’s umbilical cord.After surgery,we successfully maintained the pregnancy for 8 wk and ended it electively by cesarean section at 34 wk of gestation due to rupture of membranes.CONCLUSION TRAP should be appropriately diagnosed and treated early to avoid complications of the pump twin.Fetoscopic laser photocoagulation is a new and effective treatment for this condition.

Twin Reversed Arterial Perfusion Sequence:Prenatal Diagnosis and Treatment

Twin reversed arterial perfusion sequence,a severe and unique complication of monochorionic multiple pregnancy,is characterized by vascular anastomosis and abnormal or absent cardiac development in the twins.This article reviewed its pathogenesis,prenatal ultrasound diagnosis,and management.The pump twin’s chances for survival can be maximized by proper management.The optimal timing of the interventions remains a debate,although the latest studies encourage early intervention,i.e.,in the first trimester.The most preferred approach is to interrupt the vascular supply to the acardius,such as through ultrasound-guided laser coagulation and radiofrequency ablation of the intrafetal vessels.