title: Effect of endovascular hypothermia on acute ischemic edema: morphometric analysis of the ICTuS trial.
abstract: BACKGROUND
  Pilot studies of hypothermia for stroke suggest a potential benefit in humans. We sought to test whether hypothermia decreases post-ischemic edema using CT scans from a pilot trial of endovascular hypothermia for stroke.
  
  
  METHODS
  Eighteen patients with acute ischemic stroke underwent therapeutic hypothermia (target = 33 degrees C) for 12 or 24 h followed by a 12-h controlled re-warm using an endovascular system. CT scans obtained at baseline, 36-48 h (right after cooling and re-warming) and 30 days were digitized, intracranial compartment volumes measured using a validated stereological technique, and the calculated change in CSF volume between the three time-points were used as an estimate of edema formation in each patient. Patients were grouped retrospectively for analysis based on whether they cooled effectively (i.e., to a temperature nadir of less than 34.5 degrees C within 8 h) or not.
  
  
  RESULTS
  Eleven patients were cooled partially or not at all, and seven were effectively cooled. Baseline demographics and compartment volumes and densities were similar in both groups. At 36-48 h, the total CSF volume had significantly decreased in the not-cooled group compared to the cooled group (P < 0.05), with no significant difference in mean volume of ischemia between them (73 +/- 73 ml vs. 54 +/- 59 ml, respectively), suggesting an ameliorative effect of hypothermia on acute edema formation. At 30 days, the difference in CSF volumes had resolved, and infarct volumes (73 +/- 71 ml vs. 84 +/- 102 ml, respectively) and functional outcomes were comparable.
  
  
  CONCLUSIONS
  Endovascular hypothermia decreases acute post-ischemic cerebral edema. A larger trial is warranted to determine if it affects final infarct volume and outcome in stroke.
authors.affiliation: Department of Emergency Medicine, UCSD Medical Center, San Diego, CA, USA. kguluma@ucsd.edu
authors.forename: Kama Z
authors.initials: KZ
authors.lastname: Guluma
authors.forename: Haeryong
authors.initials: H
authors.lastname: Oh
authors.forename: Sung-Wook
authors.initials: SW
authors.lastname: Yu
authors.forename: Brett C
authors.initials: BC
authors.lastname: Meyer
authors.forename: Karen
authors.initials: K
authors.lastname: Rapp
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Lyden
mesh_terms: D000208:Acute Disease; D001831:Body Temperature; D001929:Brain Edema / Q000000981:diagnostic imaging / Q000628:therapy*; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000628:therapy*; D002404:Catheterization; D002544:Cerebral Infarction / Q000000981:diagnostic imaging / Q000628:therapy; D002555:Cerebrospinal Fluid; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D010865:Pilot Projects; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome