title: Cortical indocyanine green videography for quantification of acute hypoperfusion after subarachnoid hemorrhage:  a feasibility study.
abstract: BACKGROUND
  Acute neurological deficits after subarachnoid hemorrhage (SAH) correlate with outcome, and a phase of acute hypoperfusion was characterized recently. Indocyanine green (ICG) videography is an established intraoperative imaging technique with important descriptive potential.
  
  
  OBJECTIVE
  To analyze whether ICG can be used to analyze and confirm perfusion changes early after SAH.
  
  
  METHODS
  We prospectively enrolled 11 patients with acute SAH within the past 24 hours and 14 patients undergoing surgery for unruptured aneurysms. Cortical ICG videography was performed, and offline analysis included the arterial, parenchymal, and venous cortical compartment. Transit times, signal gradient, maximum of fluorescence intensity, and the area under the curve were calculated as surrogate markers for perfusion characteristics.
  
  
  RESULTS
  Arterial, parenchymal, and venous transit times were comparable in both groups. The velocity of signal change in SAH patients was significantly lower in all 3 compartments (P < .001, P < .01, P < .001, respectively), as was the peak fluorescence intensity (P < .001). In SAH patients, fluorescence intensity did not vary between areas with and without diffuse cortical blood. Area under the curve analysis showed significantly lower values in SAH patients compared with the control group (P < .001).
  
  
  CONCLUSIONS
  Cortical ICG videography and analysis are feasible during surgery. Patients early after SAH have a significantly lower velocity of signal change, lower peak of fluorescence intensity, and lower overall area under the curve, but similar transit times. This technique can be used to quantify perfusion alteration, in this case, acute SAH, and may be used as an adapted measurement tool for intraoperative therapy.
authors: Clinical Department of Neurosurgery, Medical University Innsbruck, Anichstrasse 35, Innsbruck, Austria. gerrit.schubert@me.com
authors: Gerrit Alexander
authors: GA
authors: Schubert
authors: Marcel
authors: M
authors: Seiz-Rosenhagen
authors: Martin
authors: M
authors: Ortler
authors: Marcus
authors: M
authors: Czabanka
authors: Kai-Michael
authors: KM
authors: Scheufler
authors: Claudius
authors: C
authors: Thomé
mesh_terms: D000328:Adult; D017542:Aneurysm, Ruptured / Q000601:surgery; D002560:Cerebrovascular Circulation; D004396:Coloring Agents; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007208:Indocyanine Green; D002532:Intracranial Aneurysm / Q000150:complications / Q000601:surgery; D008297:Male; D016343:Monitoring, Intraoperative / Q000379:methods; D019635:Neurosurgical Procedures; D013345:Subarachnoid Hemorrhage / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery*; D014741:Video Recording
chemical_list: D004396:Coloring Agents; D007208:Indocyanine Green