title: Intraoperative control of extracranial-intracranial bypass patency by near-infrared indocyanine green videoangiography.
abstract: OBJECTIVE
  Recently, intraoperative fluorescence angiography in which indocyanine green (ICG) is used as a tracer has been introduced as a novel technique to confirm successful aneurysm clipping. The aim of the present study was to assess whether ICG videoangiography is also suitable for intraoperative confirmation of extracranial-intracranial bypass patency.
  
  
  METHODS
  Forty patients undergoing cerebral revascularization for hemodynamic cerebral ischemia (11 patients), moya-moya disease (18 patients), or complex intracranial aneurysms (11 patients) were included. Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass surgery was performed 35 times in 30 patients (five patients with moyamoya underwent bilateral procedures), STA-posterior cerebral artery bypass surgery in two patients, and saphenous vein (SV) high-flow bypass surgery in eight patients. In each patient, following the completion of the anastomosis, ICG (0.3 mg/kg body weight) was given systemically via an intravenous bolus injection. A near-infrared light emitted by laser diodes was used to illuminate the operating field and the intravascular fluorescence was recorded using an optical filter-equipped video camera. The findings of ICG videoangiography were compared with those of postoperative digital subtraction (DS) or computerized tomography (CT) angiography. In all cases excellent visualization of cerebral arteries, the bypass graft, and brain perfusion was noted. Indocyanine green videoangiography was used to identify four nonfunctioning STA-MCA bypasses, which could be revised successfully in all cases. In two cases of SV high-flow bypasses, ICG videoangiography revealed stenosis at the proximal anastomotic site, which was also revised successfully. In all cases the final findings of ICG videoangiography could be positively validated during the postoperative course by performing DS or CT angiography.
  
  
  CONCLUSIONS
  Indocyanine green videoangiography provides a reliable and rapid intraoperative assessment of bypass patency. Thus, ICG videoangiography may help reduce the incidence of early bypass graft failure.
authors.affiliation: Department of Neurosurgery, University Hospital of Mannheim, Faculty for Clinical Medicine of the University of Heidelberg, Mannheim, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Woitzik
authors.forename: Peter
authors.initials: P
authors.lastname: Horn
authors.forename: Peter
authors.initials: P
authors.lastname: Vajkoczy
authors.forename: Peter
authors.initials: P
authors.lastname: Schmiedek
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction; D002548:Cerebral Revascularization; D002648:Child; D004396:Coloring Agents; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods*; D006801:Humans; D007208:Indocyanine Green; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D014741:Video Recording
chemical_list: D004396:Coloring Agents; D007208:Indocyanine Green