title: Transit-time blood flow measurements in sequential saphenous coronary artery bypass grafts.
abstract: BACKGROUND
  Little information is available on transit-time flow measurements of sequential saphenous vein grafts. The aim of the study was evaluation of mean blood flow and pulsatility index of sequential saphenous vein grafts in a large population of patients operated on with coronary artery bypass grafting.
  
  
  METHODS
  In 581 patients 1,390 grafts were nested into left internal mammary artery to left anterior descending artery, single vein grafts, or double and triple sequential vein grafts, and analyzed.
  
  
  RESULTS
  Within the single vein graft group there were no differences between flow of grafts to different target vessels except for diagonals (diagonal versus obtuse marginal, p < 0.001; versus posterior descending artery, p = 0.035; versus right coronary artery, p = 0.003). Flows measured in single vein grafts were significantly lower than in double (p < 0.001) and triple sequential vein grafts (p < 0.001). Flows were lower in double versus triple sequential vein grafts (p = 0.017) and higher in men versus women (p < 0.001). Mean pulsatility index of vein grafts were lower in the left versus the right coronary system, 2.0 +/- 0.01 and 2.4 +/- 0.06, respectively (p < 0.001). Between sex and groups of vein grafts within each coronary system, mean pulsatility index had similar values.
  
  
  CONCLUSIONS
  Blood flow increases from single to double and up to triple sequential grafts. Single grafts directed to diagonals have the lowest flow. Graft blood flows are higher in male versus female patients. Single, double, and triple saphenous vein grafts have similar pulsatility indexes. Pulsatility index of grafts to the right coronary system is significantly higher than that of grafts to the left coronary system.
authors.affiliation: Department of Circulation and Medical Imaging, The Norwegian University of Science and Technology, University of Bergen, Norway.
authors.forename: Håvard
authors.initials: H
authors.lastname: Nordgaard
authors.forename: Nicola
authors.initials: N
authors.lastname: Vitale
authors.forename: Rune
authors.initials: R
authors.lastname: Haaverstad
mesh_terms: D000368:Aged; D000787:Angina Pectoris / Q000601:surgery; D001783:Blood Flow Velocity; D001026:Coronary Artery Bypass / Q000379:methods*; D003331:Coronary Vessels / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008323:Mammary Arteries / Q000601:surgery / Q000637:transplantation*; D008875:Middle Aged; D011674:Pulse; D012039:Regional Blood Flow / Q000502:physiology; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012501:Saphenous Vein / Q000601:surgery* / Q000637:transplantation*; D013997:Time Factors