title: Graft revision after transit time flow measurement in off-pump coronary artery bypass grafting.
abstract: OBJECTIVE
  To determine whether coronary graft patency can be predicted by transit time flow measurement (TTFM).
  
  
  METHODS
  From May 1 1997 to December 31 1998, TTFM was prospectively evaluated in 409 patients undergoing coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB). All grafts (1145) were tested with TTFM.
  
  
  RESULTS
  Thirty-seven out of 1145 grafts (3.2%) were revised in 33 patients (7.6%). In six cases (18.1%) use of CPB was necessary during revision due to hemodynamic instability. The remaining patients underwent revision off-pump. Thirty-four grafts (91.9%) were revised for both low flow and abnormal flow curve patterns. Findings at revision included: thrombosis of the anastomosis (n=6), stenosis at the toe or heel of the anastomosis (n=8), coronary flap or dissection (n=5), dissection of the internal mammary artery (n=5), graft kinking (n=4), flap at proximal anastomosis (n=1), coronary stenosis distal to the graft (n=3), and no findings (n=2). After revision all flow values and flow patterns improved. Although three additional grafts (8.1%) were revised for low flow (<7 ml/min) despite normal flow patterns, there were no findings at revision and flow values and curves remained unchanged after revision. Postoperatively, one patient developed a stroke (3%), one had an acute myocardial infarction (MI) (3%), one had a sternal wound infection (3%), and one required prolonged ventilatory support (3%).
  
  
  CONCLUSIONS
  Evaluation of TTFM is valuable in determining the status of a coronary graft after CABG. Correct interpretation of flow patterns allows for correction of abnormalities prior to chest closure.
authors.affiliation: Center for Minimally Invasive Cardio-thoracic Surgery, Kaleida Health Systems and the State University of New York at Buffalo, 14203, USA.
authors.forename: G
authors.initials: G
authors.lastname: D'Ancona
authors.forename: H L
authors.initials: HL
authors.lastname: Karamanoukian
authors.forename: M
authors.initials: M
authors.lastname: Ricci
authors.forename: S
authors.initials: S
authors.lastname: Schmid
authors.forename: J
authors.initials: J
authors.lastname: Bergsland
authors.forename: T A
authors.initials: TA
authors.lastname: Salerno
mesh_terms: D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass / Q000379:methods; D003327:Coronary Disease / Q000601:surgery*; D003331:Coronary Vessels / Q000502:physiology*; D003971:Diastole / Q000502:physiology; D006801:Humans; D007387:Internal Mammary-Coronary Artery Anastomosis; D011446:Prospective Studies; D012039:Regional Blood Flow; D012086:Reoperation; D012501:Saphenous Vein / Q000637:transplantation