[Predictability of EC/IC bypass function: a retrospective study].
Although the efficacy of extracranial/intracranial bypass for reduction of risk of ischemic stroke has been denied, we have encountered patients in whom bypass operation seems to have improved his or her clinical course. The efficacy of bypass should be evaluated not by the patency of the bypass but by the extent of collateral circulation brought about by the bypass. We retrospectively analyzed our patients to determine whether the extent of bypass flow could be predicted from the results of preoperative studies. In 18 hemispheres of 18 consecutive patients who underwent extracranial/intracranial bypass surgery, correlation between the extent of bypass flow and the multiple preoperative factors including the angiographic findings were investigated. The bypass function was highly predictable in the light of preoperative studies. In all of 10 hemispheres in patients under 70 years of age and with occlusive lesions in the proximal portion of the middle cerebral artery, collateral circulation through the bypass developed to an extensive or a moderate degree. In 9 of 10 hemispheres in which an interval between the latest attack and the diagnosis of hemodynamic failure was 4 weeks or longer, collateral circulation through the bypass was shown to have developed to an extensive or a moderate degree. Our results indicate that extensive or moderate collateral circulation through the bypass can be expected only in patients under 70 years of age, with lesions in the proximal portion of the middle cerebral artery, and in whom an interval between the latest attack and diagnosis of hemodynamic failure was 4 weeks or more.
Tsuji
A
A
Department of Neurosurgery, Fukui Red Cross Hospital, Japan.
Tokuriki
Y
Y
Takebe
Y
Y
Handa
J
J
D000328:Adult; D000367:Age Factors; D000368:Aged; D002545:Brain Ischemia / Q000150:complications; D002533:Cerebral Angiography; D002548:Cerebral Revascularization; D002561:Cerebrovascular Disorders / Q000601:surgery*; D003097:Collateral Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors