title: Intraoperative assessment of coronary grafts by novel digital epivascular imaging.
abstract: OBJECTIVE
  We sought to validate and evaluate 2 novel intraoperative ultrasound probes for epicoronary and epiaortic imaging.
  
  
  BACKGROUND
  The noninvasive intraoperative assessment of successful coronary artery bypass grafting remains a challenge.
  
  
  METHODS
  A total of 19 consecutive patients (4 female, 15 male; mean age 60.5 +/- 13.8 years SD, range 34-84) underwent coronary artery bypass grafting. The epivascular probes (GE Ultrasound) were validated in vitro and intraoperatively. Coronary arteries, grafts, and ascending aorta were imaged and quantified.
  
  
  RESULTS
  Mean adjusted flow measured by flowmeter was 3.25 L, SE 0.47 (range: 1-5.5 L) and was 3.15 L, SE 0.46 (range: 1-5.0 L) by ultrasound, with r = 0.97, P <.0001. Intraoperatively, 56 native coronary vessels were bypassed using 15 left internal mammary artery grafts, 25 vein grafts, and 16 venous jump grafts. A total of 15 left internal mammary artery grafts (100%), 12 left internal mammary artery anastomoses (80%), 20 vein grafts (15 left anterior descending coronary arteries, left circumflex artery grafts, 5 right coronary artery grafts) (80%), 4 jump grafts (25%), and 15 ascending aortas (78%) were successfully imaged by inexperienced surgeons. Doppler flow measurements were possible in 50 vessels (89%). Mean lumen diameter for graft arteries (veins) was 2 mm (2.87 mm), maximal velocity was 72 cm/s (46 cm/s), and mean velocity was 29 cm/s (21 cm/s) with a mean flow rate of 70 mL/m (55 mL/m).
  
  
  CONCLUSIONS
  We conclude that: (1) the novel intraoperative probes measure validated flow; (2) intraoperative hemodynamic assessment of graft patency is feasible without a learning curve; and (3) these findings should encourage the routine use of these intraoperative epivascular digital ultrasound probes.
authors.affiliation: Heartcenter, Philipps University, USA. breburda@medicine.wisc.edu
authors.forename: Christian S
authors.initials: CS
authors.lastname: Breburda
authors.forename: Heinz
authors.initials: H
authors.lastname: Koester
authors.forename: Rainer
authors.initials: R
authors.lastname: Moosdorf
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D001026:Coronary Artery Bypass; D003326:Coronary Circulation; D003327:Coronary Disease / Q000503:physiopathology / Q000601:surgery*; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000502:physiology; D004452:Echocardiography / Q000295:instrumentation*; D015150:Echocardiography, Doppler / Q000295:instrumentation; D005260:Female; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods; D014654:Vascular Patency