title: Intraoperative fluorescence imaging system for on-site assessment of off-pump coronary artery bypass graft.
abstract: OBJECTIVE
  The aim of this study was to evaluate the intraoperative fluorescence imaging (IFI) system in the real-time assessment of graft patency during off-pump coronary artery bypass graft.
  
  
  BACKGROUND
  Intraoperative fluorescence imaging is an intraoperative angiography-like imaging modality using fluorescent indocyanine green excited with laser light. Recently, assessment of graft patency using the IFI system was introduced into clinical use. The feasibility and efficacy of IFI technology in off-pump coronary artery bypass graft has not been systematically compared with other conventional diagnostic modalities.
  
  
  METHODS
  Patients undergoing off-pump coronary artery bypass graft received IFI analysis, intraoperative transit time flowmetry, and postoperative X-ray angiography. In off-line IFI analysis, the graft washout was classified based on the number of heartbeats required for indocyanine green washout: fast washout (<or=15 beats) and slow washout (>15 beats).
  
  
  RESULTS
  A total of 507 grafts in 137 patients received IFI analysis. Of all the IFI analyses, 379 (75%) grafts were visualized clearly up to the distal anastomosis. With regard to anastomosis location, anterior location was associated with a higher percentage of fully analyzable images (90%). More than 80% of images were analyzable, irrespective of graft type. Six grafts with acceptable transit time flowmetry results were diagnosed with graft failure by IFI, which required on-site graft revision. All revised grafts' patency was confirmed by post-operative X-ray angiography. Conversely, 21 grafts with unsatisfactory transit time flowmetry results demonstrated acceptable patency with IFI. Graft revision was considered unnecessary in these grafts, and 20 grafts (95%) were patent by post-operative X-ray angiography. Compared with slow washout, fast washout was associated with a higher preoperative ejection fraction, use of internal mammary artery grafts, and anterior anastomosis location.
  
  
  CONCLUSIONS
  The IFI system enables on-site assessment of graft patency, providing both morphologic and functional information. This technique may help reduce procedure-related, early graft failures in off-pump bypass patients.
authors.affiliation: Stanford University Medical Center, Stanford, California 94305, USA.
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Waseda
authors.forename: Junya
authors.initials: J
authors.lastname: Ako
authors.forename: Takao
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Shimada
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Ikeno
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Demura
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Hatada
authors.forename: Paul G
authors.initials: PG
authors.lastname: Yock
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Honda
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Fitzgerald
authors.forename: Masao
authors.initials: M
authors.lastname: Takahashi
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D017023:Coronary Angiography; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D003326:Coronary Circulation; D015150:Echocardiography, Doppler; D005240:Feasibility Studies; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods*; D005456:Fluorescent Dyes / Q000008:administration & dosage; D006083:Graft Occlusion, Vascular / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D007208:Indocyanine Green / Q000008:administration & dosage; D007275:Injections, Intravenous; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011237:Predictive Value of Tests; D014654:Vascular Patency; D014741:Video Recording
chemical_list: D005456:Fluorescent Dyes; D007208:Indocyanine Green