Hyperperfusion Syndrome after Extracranial-Intracranial Bypass Surgery

ABSTRACT

OBJECTIVE: Cerebral hyperperfusion syndrome after extracranial-intracranial(EC-IC) bypass is a rare event but it may be disastrous. It can cause vomiting, confusion, seizure and intracerebral hemorrhage. We report 11 cases of hyperperfusion syndrome after EC-IC bypass surgery for recent 5 years in detail. METHODS: Authors performed EC-IC bypass surgery for augmentation of cerebral blood flow in 60 patients for recent 5 years. In 60 patients of EC-IC bypass procedures, we experienced 11 cases of hyperperfusion syndrome. It was observed that hyperfusion induced headache and vomiting in 2 cases, seizure in 1 case, temporary neurologic deficit in 5 cases, and intracerebral hemorrhage in 3 cases. RESULTS: All patients except three cases of intracerebral hemorrhag recovered completely. Five patients with temporary neurologic deficit improved within maxmum of 10days. In three cases of intracerebral hemorrhage, emergency hematoma removal was performed. Two of them, with moyamoya disease, recovered with minor neurologic deficit. The other, with traumatic intracarotid artery injury died. CONCLUSION: Hyperfusion syndromes may be due to relative hyperperfusion of a cerebral hemisphere in which autoregulation had been impaired because of preoperative chronic hypoperfusion. We strongly recommend that revascularization is deferred to 8 weeks till impaired autoregulation is restored, and meticulous blood pressure control should be done in the postoperative course of EC-IC bypass surgery.