Cerebral hyperperfusion syndrome post-carotid artery stenting.

Cerebral hyperperfusion syndrome is increasingly recognized as a complication in carotid artery stenting for severe internal carotid artery stenosis. This study reviews the cases of hyperperfusion syndrome occurring after this procedure. We reviewed our database of 170 cases of internal carotid artery stenting carried out at our hospital between January 1999 and June 2006. A radiology search was also carried out to identify those who had CT or MRI within 1 month of post-carotid artery stenting. We had four patients who developed cerebral hyperperfusion syndrome. One patient developed cerebral oedema, one patient had petechial intracerebral haemorrhage and two patients had large intracerebral haemorrhages, one of whom died. This gives a risk of 2.3% (95% confidence interval 2.27-2.323). All patients with cerebral haemorrhage presented within 6 h. Both patients with large intracerebral haemorrhage had carotid stenting within 3 weeks after presentation of symptoms and all had critically severe stenosis of 95% or more. In our series, large intracerebral haemorrhage has occurred only in patients who have been treated early. Cerebral hyperperfusion is an uncommon but serious complication post-carotid stenting. Further studies comparing early treatment of endarterectomy and carotid stenting are awaited.