title: The impact of early perfusion CT measurement after extracranial-intracranial bypass surgery: results of a pilot study.
abstract: OBJECTIVE
  The early postoperative period after extracranial-intracranial bypass surgery carries the risk of hypo- as well as hyperperfusion. The purpose of this study is to evaluate early perfusion computerized tomography (PCT) after revascularization to assess the hemodynamic balance.
  
  
  METHODS
  Standard cerebral bypass surgery was performed on ten patients, and PCT measurement within 6 h after surgery was performed and analyzed.
  
  
  RESULTS
  The hemisphere with reduced cerebral vascular reserve (CVR) showed a regional cerebral baseline blood flow (CBF) of 5.58 ± 1.69 and a regional cerebral baseline blood volume (CBV) of 2.41 ± 0.76 before surgery. Mean transit time (MTT) was 4.16 ± 0.9 s and time to peak (TTP) 3.25 ± 1.62 s. After the procedure values changed significantly (p < 0.05) in eight patients who had no complications. Patency rate was documented in all patients by angiography. One patient showed a decrease of CBF and CBV and an increase of MTT and TTP. Clinically the patient developed a transient hemiparesis immediately after surgery. Another patient showed the expected increase in CBF and CBV; however, MTT and TTP also increased. A delayed hemiparesis probably related to hyperperfusion occurred with improvement in the follow-up.
  
  
  CONCLUSIONS
  This pilot study demonstrates that early PCT parameters can provide immediate and detailed information about hemodynamic parameters and seems to have a predictive value regarding the morbidity of hypo- or hyperperfusion in patients after cerebral bypass surgery.
authors.affiliation: Department of Neurosurgery, Heinrich Heine University, Düsseldorf, Germany. eicker.s@mac.com
authors.forename: Sven O
authors.initials: SO
authors.lastname: Eicker
authors.forename: Kerim
authors.initials: K
authors.lastname: Beseoglu
authors.forename: Nima
authors.initials: N
authors.lastname: Etminan
authors.forename: Bernd
authors.initials: B
authors.lastname: Turowski
authors.forename: Hans-Jakob
authors.initials: HJ
authors.lastname: Steiger
authors.forename: Daniel
authors.initials: D
authors.lastname: Hänggi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002340:Carotid Artery Diseases / Q000601:surgery*; D002548:Cerebral Revascularization / Q000379:methods*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010477:Perfusion; D010865:Pilot Projects; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult