Analysis of factors influencing the values of parameters of intraoperative flowmetry of coronary bypass grafts: retrospective single-center cross-sectional study

Оbjective. This study determines the factors that can affect the value of the parameters of intraoperative flowmetry of coronary bypass grafts.

Material and methods. TTFM is a routine procedure accompanying coronary artery bypass grafting at the Federal State Budgetary Institution FTSSSh (Penza). This retrospective study included 995 consecutive patients who underwent isolated coronary artery bypass grafting of the left coronary artery. The exclusion criteria were damage to the right coronary artery bed, the emergency nature of the operation, and the combined pathology of the valvular apparatus. Patients who underwent anastomosis revision due to flowmetry parameters changes were also excluded from the study. Intraoperative assessment of coronary artery bypass grafts was performed using VeryQ and MiraQ MediStim® flowmeters (Norway).

Results. A total of 1733 arterial and 479 venous grafts were evaluated. The following factors influenced the average volumetric blood flow velocity value: composite shunting of the border stenosis increases the chance of reducing the volumetric blood flow below the threshold value by 1.841 times (OR=1.841; p=0.018), the combination of occlusion and borderline stenosis with composite shunting increases the chance of reducing the volumetric blood flow velocity by 3.91 times (OR=3.91; p=0.041), an increase in the diameter of the bypassed artery by 1.0 mm reduces the chance of a decrease in blood flow volume velocity by 53.7% (OR=0.423; p=0.05).

Conclusion. The following factors influence the peripheral resistance index: coronary artery diameter (OR=0.21; p=0.001), degree of artery proximal stenosis (OR=0.987; p=0.034), the vascular wall condition (OR=2.25; p=0.05), type of conduit used (OR=0.298; p=0.002), and shunting method (OR=1.699; p=0.017). The following factors influence the mean volumetric blood flow velocity value: bypass method (OR=1.841; p=0.018), a combination of occlusion and borderline stenosis in composite bypass grafting (OR=3.91; p=0.041), and the bypassed artery diameter (OR=0.423; p=0.423; p=0.05).