Background: Intraoperative transit time flow measurement (TTFM) of left internal thoracic (L-ITA) and saphenous vein (SV) grafts (SVG) can improve graft patency and, consequently, clinical outcome in patients undergoing coronary artery bypass grafting (CABG). We have investigate if there were differences in female and male gender on TTFM -flow (mL/min) and pulsatility index (PI)- measured at the weaning form cardio-pulmonary bypass after CABG and early results. We started to use TTFM on September 2022.
Methods: Between September 2022 and September 2023, TTFM was performed in 101 patients (21 females, 80 males) undergoing CABG, isolated (n=75) or in association with other procedures (n=26).
Results: No significant differences were observed in age (66.2±11 vs 66.9±9 years; P=0.81), Euroscore-2 (4.2±3 vs 3.8±3; P=0.24), left ventricular ejection fraction (54±8 vs 52±9; P=0.08). Associated procedures were more frequently performed in females (47.6% vs 20%; 0.05). Left anterior descending artery (1.4±0.2 vs 1.6±0.2 mm; P=0.001), first obtuse marginal branch (1.3±0.2 vs 1.5±0.3 mm; 0.05), right posterior artery (1.2±0.2 vs 1.4±0.3 mm; 0.05) diameters were smaller in females. TTFM flow of L-ITA or SV grafts on the left anterior descending artery (28±9 vs 38±18 mL/min; 0.05), first obtuse marginal branch (27±15 vs 42±28 mL/min; 0.05), right posterior descending artery (29±11 vs 36±19 mL/min; P>0.5) was lower in females. No PI values differences were observed in the coronary arteries territories (3.9±0.8 vs 3.7±0.9; 3.8±0.5 vs 3.9±1; 3.5±0.9 vs 3.3±1) (P>0.5). There were no operative mortality and major cardio-vascular complications; postoperative respiratory failure occurred in three males.
Conclusions: As compared with their male counterpart, the lower values of L-ITA and SV grafts flow observed in females can be related to the smaller diameter of coronary arteries rather than to their vascular resistance. However, the reduced graft flow observed in female gender does not affect early outcomes.