title: Cerebral hyperemia after arteriovenous malformation resection is related to "breakthrough" complications but not to feeding artery pressure. The Columbia University Arteriovenous Malformation Study Project.
abstract: To study the pathophysiology of idiopathic postoperative brain swelling or hemorrhage after arteriovenous malformation resection, termed normal perfusion pressure breakthrough (NPPB), we performed cerebral blood flow (CBF) studies during 152 operations in 143 patients, using the xenon-133 intravenous injection method. In the first part of the study, CBF was intraoperatively measured (isoflurane/N2O anesthesia) during relative hypocapnia in 95 patients before and after resection. The NPPB group had a greater increase (P < 0.0001) in mean +/- standard deviation global CBF (28 +/- 6 to 47 +/- 16 ml/100 g/min, n = 5) than did the non-NPPB group (25 +/- 7 to 29 +/- 10 ml/100 g/min, n = 90); both arteriovenous malformation groups showed greater increase (P < 0.05) than did controls undergoing craniotomy for tumor (23 +/- 6 to 23 +/- 6 ml/100 g/min, n = 22). Ipsilateral and contralateral CBF changes were similar. In a second cohort of patients with arteriovenous malformations, CBF was measured at relative normocapnia and it increased (P < 0.002) from pre- to postresection (40 +/- 13 to 49 +/- 15 ml/100 g/min, n = 57). There were no NPPB patients in this latter cohort. The feeding mean arterial pressure was measured intraoperatively before resection or at the last embolization before surgery (n = 64). The feeding mean arterial pressure (44 +/- 16 mm Hg) was 56% of the systemic arterial pressure (78 +/- 12 mm Hg, P < 0.0001) and was not related to changes in CBF from pre- to postresection. There was an association between increases in global CBF from pre- to postresection and NPPB-type complications, but there was no relationship of these CBF changes to preoperative regional arterial hypotension. These data do not support a uniquely hemodynamic mechanism that explains cerebral hyperemia as a consequence of repressurization in hypotensive vascular beds.
authors.affiliation: Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, USA.
authors.forename: W L
authors.initials: WL
authors.lastname: Young
authors.forename: A
authors.initials: A
authors.lastname: Kader
authors.forename: E
authors.initials: E
authors.lastname: Ornstein
authors.forename: K Z
authors.initials: KZ
authors.lastname: Baker
authors.forename: N
authors.initials: N
authors.lastname: Ostapkovich
authors.forename: J
authors.initials: J
authors.lastname: Pile-Spellman
authors.forename: P
authors.initials: P
authors.lastname: Fogarty-Mack
authors.forename: B M
authors.initials: BM
authors.lastname: Stein
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D001794:Blood Pressure / Q000502:physiology*; D001921:Brain / Q000098:blood supply*; D001929:Brain Edema / Q000503:physiopathology; D001932:Brain Neoplasms / Q000503:physiopathology / Q000601:surgery; D002245:Carbon Dioxide / Q000097:blood; D002536:Cerebral Arteries / Q000503:physiopathology / Q000601:surgery; D002543:Cerebral Hemorrhage / Q000503:physiopathology; D002648:Child; D015331:Cohort Studies; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D006940:Hyperemia / Q000503:physiopathology*; D002538:Intracranial Arteriovenous Malformations / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D011183:Postoperative Complications / Q000503:physiopathology*; D011559:Pseudotumor Cerebri / Q000503:physiopathology; D012016:Reference Values
chemical_list: D002245:Carbon Dioxide