Graft revision after transit time flow measurement in off-pump coronary artery bypass grafting

Eur J Cardiothorac Surg. 2000 Mar;17(3):287-93. doi: 10.1016/s1010-7940(00)00332-8.


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%).

Conclusion: 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.

MeSH terms

  • Cardiopulmonary Bypass
  • Coronary Artery Bypass* / methods
  • Coronary Disease / surgery*
  • Coronary Vessels / physiology*
  • Diastole / physiology
  • Humans
  • Internal Mammary-Coronary Artery Anastomosis
  • Prospective Studies
  • Regional Blood Flow
  • Reoperation
  • Saphenous Vein / transplantation