Evaluation of gastroepiploic arterial grafts to right coronary artery using transit-time flow measurement

Objectives: The objective of this study was to analyse the relationship between the intraoperative transit-time flow measurement (TTFM) parameter values and the postoperative angiographic results of gastroepiploic arterial (GEA) grafts to the right coronary artery (RCA). We investigated whether the intraoperative TTFM parameter values are reliable indicators of early patency in GEA grafts to the RCA.

Methods: Patients undergoing off-pump coronary artery bypass surgery with GEA grafts were included in this study. Eighty-three GEA grafts were individually anastomosed and examined by angiography 1 week after surgery. The quality of each graft was graded using FitzGibbon grading (Study 1) and graft-flow grading (Study 2).

Results: Study 1: Seventy-two grafts were determined as Grade A and 11 as Grades B or O. There were no significant differences in the average of mean graft flow (MGF), pulsatility index or diastolic filling percentage between Grade A and Grades B or O grafts. Study 2: Sixty-two grafts were graded as good-graft dominant, 16 as bidirectional and 5 as occlusion including string. The average of the MGF, pulsatility index and diastolic filling percentage in the grafts graded as bidirectional and occlusion including string were not significantly different from those of grafts graded as good-graft dominant.

Conclusions: Previously reported cut-off values for intraoperative TTFM parameters could not be adapted for the early patency of GEA grafts to the RCA. However, the smoothness of the graft-flow curve may be a reliable predictor of postoperative graft patency.