twin embolisation syndrome
description
twin embolisation syndrome is a complication of monozygotic twinning following in utero demise of the co-twin. it results from embolisation of placentary and fetal thromboplastins, direct embolization of necrosed placental fragments, disseminated intravascular coagulation, or even infectious endarteritis. these emboli damage predominantly highly vascular organs such as the brain and kidneys, but can affect almost all organ systems. in the central nervous system embolisation can result in ventriculomegaly, porencephaly, cerebral atrophy, leukomalacia or microcephaly. extracranial abnormalities include small bowel atresia, gastroschisis, hydrothorax, aplasia cutis and renal cortical necrosis.
diagnosis
the possibility of twin embolisation must always be considered in a monochorionic pregnancy following in utero demise of one twin. cranial examination of the surviving twin may demonstrate one or more signs: ventriculomegaly, porencephaly, leukomalacia or microcephaly. extracranial evidence of embolisation is indicated in the presence of bowel atresia, gastroschisis, hydrothorax.
differential diagnosis
other causes of the associated signs already listed should be considered if both twins are viable and apparently uncompromised.
sonographic features
dead twin
surviving twin with intracranial signs (ventriculomegaly, porencephaly, microcephaly) or systemic anomalies (bowel atresia, gastroschisis, hydrothorax)