title: Improving the quality of coronary bypass surgery with intraoperative angiography: validation of a new technique.
abstract: OBJECTIVE
  We report a comprehensive assessment and validation of a new intraoperative angiography technique.
  
  
  BACKGROUND
  Technical problems at the site of the distal anastomosis compromise an underappreciated proportion of coronary bypass grafts. The absence of a systematic, validated technique to verify graft patency in the operating room represents a significant breach in quality assurance.
  
  
  METHODS
  Fluorescent indocyanine green (ICG) dye is excited with dispersed laser light to create an angiographic depiction of the graft, native vessel, and anastomosis. One-hundred twenty patients underwent ICG angiography. Angiograms were reviewed for reliability and validity studies.
  
  
  RESULTS
  A total of 348 coronary bypass grafts were studied. Each ICG angiogram took 2.2 +/- 1.1 min to perform. The ICG angiography found 4.2% of patients had significant graft problems requiring major revision. Quality of visualization was rated according to a seven-point Likert scale (1 = worst, 7 = best). Among conduits, saphenous veins were best visualized (mean score +/- standard deviation), 6.4 +/- 1.5 versus 5.5 +/- 1.9 for internal mammary arteries and 4.4 +/- 2.3 for radial arteries (p = 0.02). Location of distal anastomosis did not influence quality of visualization. There was high inter-rater reliability for graft revision (kappa = 1.0) and graft patency (kappa = 0.97) between surgeons. Sensitivity and specificity of the ICG angiograms for graft stenosis >50% was 100% among 22 grafts also studied with X-ray angiography.
  
  
  CONCLUSIONS
  Information from ICG angiograms led to graft revisions for technical problems in 4.2% of patients that would have otherwise gone unrecognized. Intraoperative angiography is an emerging tool for improving the quality of coronary bypass surgery.
authors.affiliation: Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada. nimesh.desai@utoronto.ca
authors.forename: Nimesh D
authors.initials: ND
authors.lastname: Desai
authors.forename: Senri
authors.initials: S
authors.lastname: Miwa
authors.forename: David
authors.initials: D
authors.lastname: Kodama
authors.forename: Gideon
authors.initials: G
authors.lastname: Cohen
authors.forename: George T
authors.initials: GT
authors.lastname: Christakis
authors.forename: Bernard S
authors.initials: BS
authors.lastname: Goldman
authors.forename: Mark O
authors.initials: MO
authors.lastname: Baerlocher
authors.forename: Marc P
authors.initials: MP
authors.lastname: Pelletier
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Fremes
mesh_terms: D000368:Aged; D004396:Coloring Agents; D017023:Coronary Angiography; D001026:Coronary Artery Bypass / Q000592:standards*; D005260:Female; D006801:Humans; D007208:Indocyanine Green; D007430:Intraoperative Care; D008297:Male; D011446:Prospective Studies; D015203:Reproducibility of Results
chemical_list: D004396:Coloring Agents; D007208:Indocyanine Green