Treatment for intracranial cerebral artery stenosis.

Symptomatic intracranial cerebral artery stenosis is largely resistant to drug treatment. Regardless of their locations, lesions may cause cerebral infarction with a frequency of 7-10% in a year, but the natural history of asymptomatic intracranial cerebral artery stenosis remains unclear. Revascularization is indicated for symptomatic lesions which show resistance to drug treatment, while bypass surgery is the accepted therapeutic indication for haemodynamic ischemia. Endovascular treatment is effective in haemodynamic ischemia, and is also expected to be effective against embolic symptoms. Bypass surgery for anterior circulation cases is safe because of its low incidence of complications, whereas bypass surgery for posterior circulation cases is technically difficult and has a high associated complication rate. Hence, endovascular treatment is currently favored for posterior circulation cases, and has also been introduced for anterior circulation cases. Endovascular treatment has become a widespread modality for intracranial cerebral artery stenosis, but there are many unsolved problems associated with complications, technology and devices. Therefore, in practice, endovascular treatment should be used only with a strict indication, and should be performed only after considerable thought and with appropriate informed consent.