Intracerebral haematomas with agenesis of the internal carotid artery and tetralogy of Fallot.

We report a rare case with tetralogy of Fallot (TOF) and agenesis of the internal carotid artery (ICA) who presented serious intracerebral haematomas. In the literature, this is the first documented case having these complications simultaneously. Extreme hypoxic insults followed by recovery were detected by O2 saturation monitor before two bleeds. Chronic brain hypoxia could make the vasculature weak, which was shown in the histological examination. A 2-year-old girl was transferred to us with a general convulsion due to intracerebral haematoma. She had been showing general cyanosis from birth due to TOF. Repeated intracerebral haemorrhages ended her life. Histological study showed dilated vascular channels in the subarachnoid space and necrotizing vasculature obstructed by fibrinous thrombi adjacent to the haematoma. Fibrosis of the vessel wall with infiltration of macrophages suggested subacute or chronic lesions rather than acute necrosis due to the multiple haemorrhages. The intracerebral haematomas and agenesis of the ICA were observed as unilateral hemispheric vascular complications of TOF. Chronic brain hypoxia could play an important role in weakening the vessel wall and erythrocytosis caused obstructing thrombi. We speculate these factors generated the intracerebral haematomas.