Effects of hypercapnia on cerebral blood flow following prophylactic and delayed experimental superficial temporal artery-middle cerebral artery bypass.
Cerebral blood flow was studied in dogs to ascertain whether preexisting superficial temporal artery-middle cerebral artery bypass could preserve hypercapnic reactivity following acute ischemia and whether postischemic-delayed revascularization would restore hypercapnic reactivity. In six dogs flow was preserved and some degree of hypercapnic response remained following proximal occlusion with a patent bypass. During complete ischemia (bypass occluded) there was no hypercapnic reactivity in the ischemic zone. Significant flow was restored to the ischemic area following bypass reopening, but a cerebral blood flow decrease was seen with subsequent hypercapnia. In the opposite (control) hemisphere hypercapnia always produced significant cerebral blood flow increases. These data support the superiority of prophylactic over delayed superficial temporal artery-middle cerebral artery bypass in appropriate clinical situations.
Loftus
C M
CM
Division of Neurosurgery, Iowa City Veterans Administration Hospital, Iowa.
Silvidi
J A
JA
Bernstein
D D
DD
Kosier
T
T
D000818:Animals; D002545:Brain Ischemia / Q000150:complications / Q000503:physiopathology / Q000601:surgery; D002548:Cerebral Revascularization; D002560:Cerebrovascular Circulation; D004285:Dogs; D006935:Hypercapnia / Q000150:complications / Q000503:physiopathology*; D013997:Time Factors