title: The impact of competitive flow on distal coronary flow and on graft flow during coronary artery bypass surgery.
abstract: To determine the impact of left anterior descending-competitive flow (LAD-CF) on distal coronary flow (LAD-DF) and on left internal mammary artery-graft flow (LIMA-GF), we performed a quantitative blood-flow analysis in a swine model of a LIMA-to-LAD coronary artery bypass graft (CABG). In six swine, a LIMA-to-LAD CABG was performed. LAD blood-flow was measured bilaterally to the LIMA-to-LAD anastomosis, in the LIMA and in the pulmonary artery (cardiac output, CO) along with the LIMA pulsatility index (LIMA-PI) and the left ventricular pressure (LVP). PreCABG measurements were followed by postCABG measurements at five levels of LAD-CF: 100%, 75%, 50%, 25% and 0% after gradually snaring down a snare placed proximally of the LAD-CF flow-probe. PreCABG CO and LVP remained unchanged postCABG. LAD-DF was reduced significantly postCABG (-33%, P<0.0001). Reduction of the LAD-CF (at 75%, 50%, 25% and 0%) resulted in significant increase of LIMA-GF (+38%, +63%, +113%, +225%, P<0.036 at all LAD-CF levels), reduced PI (6.8, 5.7, 4.1, 3.1, 2.5) with simultaneous increase of LAD-DF (+8%, P=NS, +8%, P=NS, +17%, P=NS, +50%, P=0.0044). Decreased LAD-CF resulted in increased LAD-DF, increased LIMA-GF and decreased LIMA-PI. To the best of our knowledge, this is the first study where blood-flow was directly and simultaneously measured in all the components of the LIMA-to-LAD anastomosis.
authors: Division of CardioVascular Surgery, Mayo Clinic, Rochester, MN, USA. tsirikos.nikolaos@mayo.edu
authors: Nikolaos
authors: N
authors: Tsirikos Karapanos
authors: Scott H
authors: SH
authors: Suddendorf
authors: Zhuo
authors: Z
authors: Li
authors: Marianne
authors: M
authors: Huebner
authors: Lyle D
authors: LD
authors: Joyce
authors: Soon J
authors: SJ
authors: Park
mesh_terms: D000818:Animals; D002302:Cardiac Output; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000503:physiopathology / Q000601:surgery*; D006439:Hemodynamics; D007387:Internal Mammary-Coronary Artery Anastomosis / Q000009:adverse effects; D017078:Laser-Doppler Flowmetry; D008297:Male; D023421:Models, Animal; D011651:Pulmonary Artery / Q000503:physiopathology; D011652:Pulmonary Circulation; D011673:Pulsatile Flow; D013552:Swine; D013997:Time Factors; D016277:Ventricular Function, Left; D017725:Ventricular Pressure