Complications of endovascular MCA clot retrieval: hydrophilic polymer brain embolisation, localised MCA angiitis and recurrent ischaemic strokes

Reported cases of hydrophilic polymer embolisation (HPE) to the brain secondary to neurovascular procedures are rare. 1 A 72-year-old male presented with right MCA stroke, managed successfully with endovascular clot retrieval and angioplasty at M2. The patient represented four months later with recurrent right-sided ischaemic stroke followed rapidly by multiple successive ischaemic strokes. Postmortem examination revealed multiple bilateral infarcts and atherosclerosis of the cerebral and basilar arteries. There were foreign body-type giant cells associated with weakly polarisable and non-birefringent basophilic material in the right hemisphere capillaries. The right M2 MCA contained multinucleated foreign body-type giant cells on the luminal surface with patchy subluminal necrosis and sparse mural T-lymphocytes. There was background myointimal hyperplasia and duplication of the elastic lamina.