title: Peroperative hemodynamic study of left internal mammary artery grafts.
abstract: The present study was undertaken to analyse hemodynamic features of an arterial graft and to determine parameters which influence primarily flow and velocity. A total of 284 consecutive patients having isolated coronary bypass surgery underwent peroperative hemodynamic assessment by pulsed Doppler ultrasonics of a left internal mammary artery bypass graft implanted onto the left anterior descending artery. Internal mammary artery free flow was 109.2 +/- 3.7 ml/min and flow in the internal mammary artery measured after completion of the distal anastomosis was 70.9 +/- 2.7 ml/min. All values quoted are mean +/- standard error of the mean. Mean velocity was 21.2 +/- 0.6 cm/sec, internal diameter was 2.65 +/- 0.04 mm and pulsatility index was 2.24 +/- 0.12. Resistance was expressed as mmHg/(ml . min-1) and averaged 1.65 +/- 0.13 for total resistance, 0.87 +/- 0.05 for graft resistance, and 0.73 +/- 0.13 for coronary resistance. From a set of 35 variables, stepwise multiple regression analysis selected two parameters influencing independently flow in internal mammary artery (R2 = 0.8762): flow velocity (p < 10(-4)) and internal diameter (p < 10(-4)). Variables influencing velocity (R2 = 0.3071) were: pulsatility index, which is a dimensionless expression of peripheral resistance (p < 10(-4)), and free internal mammary artery flow (p = 0.0007). Furthermore, a significant correlation between internal diameter and total resistance was observed (R = -0.5363, p < 10(-4), Y = 1.676X-1.545), and the exponentially fitted regression line was characterized by a marked increase of resistance at diameters less than 2 mm.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Division of Cardiovascular and Thoracic Surgery, University Hospital of Mont-Godinne (Catholic University of Louvain), Yvoir, Belgium.
authors.forename: Y A
authors.initials: YA
authors.lastname: Louagie
authors.forename: J P
authors.initials: JP
authors.lastname: Haxhe
authors.forename: J
authors.initials: J
authors.lastname: Jamart
authors.forename: O
authors.initials: O
authors.lastname: Gurne
authors.forename: M
authors.initials: M
authors.lastname: Buche
authors.forename: J C
authors.initials: JC
authors.lastname: Schoevaerdts
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007387:Internal Mammary-Coronary Artery Anastomosis; D008297:Male; D008323:Mammary Arteries / Q000033:anatomy & histology; D008875:Middle Aged; D018617:Ultrasonography, Doppler, Pulsed