Intraoperative transit time flowmetry during off-pump coronary artery bypass grafting: Early outcome of two different anastomosis technique.

Introduction: Intraoperative transit time flowmetry (TTF) is an essential technique for evaluating graft function during off-pump coronary artery bypass grafting (OPCABG). This study compares graft quality and outcomes using TTF in two surgical approaches: sequential and Y-type saphenous vein grafting.

Methods: A total of 120 patients with triple-vessel coronary artery disease were enrolled and randomized into two groups: Group 1 (n=60) received sequential grafts; Group 2 (n=60) received Y-grafts. Mean graft flow (MGF) and pulsatility index (PI) were measured intraoperatively. Graft function was classified based on flow>15 ml/min and PI<2.5. All patients underwent coronary CT angiography at 48 months to assess graft patency.

Results: Intraoperative TTF showed no significant difference in MGF or PI between graft types, although sequential grafts demonstrated slightly higher flow and lower resistance. Intraoperative graft failure occurred in 1.7% (sequential) vs. 3.3% (Y-grafts). At 48-month follow-up, sequential grafts showed 100% patency, while Y-grafts had a 7.0% occlusion rate. Multivariate analysis identified vessel diameter and conduit type as significant predictors of graft performance; graft configuration (sequential vs. Y) was not independently predictive.

Conclusion: TTF is a valuable intraoperative tool for ensuring graft functionality in OPCABG. While both techniques are viable, sequential grafting demonstrated superior mid-term patency and lower failure rates. These findings support the preferential use of sequential grafting when anatomically feasible and highlight the importance of routine TTF to optimize surgical outcomes.