title: Intracranial venous pressures under conscious sedation and general anesthesia.
abstract: BACKGROUND
  Venous outflow obstruction has been implicated in the pathophysiology of a subset of patients with idiopathic intracranial hypertension (IIH), and venous sinus stenting (VSS) has emerged as an effective treatment. However, the effect of anesthesia on venous sinus pressure measurements is unpredictable. A more thorough understanding of the effect of the level of anesthesia on intracranial venous pressures might help to better define patients who might benefit most from stent placement.
  
  
  OBJECTIVE
  To compare, in a retrospective cohort study, intracranial venous pressures measured under conscious (CS) sedation versus general anesthesia (GA) and to assess the relationship between anesthetic-dependent venous pressures and outcomes after VSS.
  
  
  METHODS
  We performed a retrospective review of a prospectively maintained database to identify patients undergoing angiographic evaluation and VSS for intracranial venous stenosis. Mean venous pressures (MVPs) and trans-stenosis pressure gradients obtained under CS were compared with those measured under GA.
  
  
  RESULTS
  The maximal MVP was significantly lower under GA (19.8 mm Hg) than CS (21.9 mm Hg; p=0.029). The MVPs in the superior sagittal sinus, torcula, and transverse sinus were lower under GA, but were significantly higher in the sigmoid sinus and jugular bulb under GA (p<0.001). The mean trans-stenosis pressure gradient was also significantly lower under GA (8.6 mm Hg) than CS (12.1 mm Hg; p<0.001). Patients with a larger difference between maximum MVP under GA versus CS were more likely to have normalization of the MVP after VSS (p=0.0008).
  
  
  CONCLUSIONS
  Intracranial venous pressures are markedly affected by GA. In order to obtain an accurate measurement of MVPs and trans-stenosis gradients, patients undergoing investigation for IIH should undergo cerebral angiography and venous manometry under CS, which provides more reliable data for outcomes after VSS.
authors.affiliation: Department of Neurosurgery, University of Virginia Health System, Charlottesville, Virginia, USA.
authors.forename: Daniel M S
authors.identifier: http://orcid.org/0000-0003-3378-5345
authors.initials: DMS
authors.lastname: Raper
authors.affiliation: Department of Neurosurgery, University of Virginia Health System, Charlottesville, Virginia, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Buell
authors.affiliation: Department of Neurosurgery, University of Virginia Health System, Charlottesville, Virginia, USA.
authors.forename: Ching-Jen
authors.initials: CJ
authors.lastname: Chen
authors.affiliation: Department of Neurosurgery, University of Virginia Health System, Charlottesville, Virginia, USA.
authors.forename: Dale
authors.initials: D
authors.lastname: Ding
authors.affiliation: Deparment of Neurological Surgery, Miller School of Medicine, University of Miami, Miami, Florida, USA.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Starke
authors.affiliation: Department of Neurosurgery, University of Virginia Health System, Charlottesville, Virginia, USA.|Department of Radiology, University of Virginia Health System, Charlottesville, Virginia, USA.
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000768:Anesthesia, General / Q000009:adverse effects / Q000639:trends*; D015331:Cohort Studies; D016292:Procedural Sedation / Q000009:adverse effects / Q000639:trends*; D003251:Constriction, Pathologic / Q000000981:diagnostic imaging / Q000601:surgery; D003392:Cranial Sinuses / Q000000981:diagnostic imaging* / Q000502:physiology / Q000601:surgery; D005260:Female; D006801:Humans; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011559:Pseudotumor Cerebri / Q000000981:diagnostic imaging / Q000601:surgery; D012189:Retrospective Studies; D054064:Transverse Sinuses / Q000000981:diagnostic imaging / Q000502:physiology / Q000601:surgery; D016896:Treatment Outcome; D014690:Venous Pressure / Q000502:physiology; D055815:Young Adult
keywords: Angiography; Intracranial Pressure; Stenosis; Stent; Vein