Total arterial coronary revascularization - Single or double inlet system?

Background The study assessed the graft flow to the coronary arteries during coronary artery bypass grafting in 175 patients receiving a composite single or double mammary grafts. Methods 128 patients with single inlet and 47 with double inlet composite arterial grafts were evaluated. In on pump — prior to, and following release of aortic cross clamp-and in off pump settings, graft blood flow was measured using an ultrasonic Transit Time Volume flowmeter. Results On pump, unrestricted blood flow was lower in single inlet than in double inlet grafts (119.9 ± 6.9 ml/min versus 161.0 ± 14.0ml/min (P=0.0042). There was also significantly less blood flow through the single inlet system when the heart was beating (74.7 ± 3.7 ml/min versus 98.0 ± 8.1 ml/min (P=0.0018)). We also found that patients operated on pump had larger graft flow than patients operated off pump (85.6 ± 4.6 ml/min versus 69.5 ± 3.8ml/min (P = 0.042)). Gender and number of anastomoses to the coronary arteries, were not predictive for graft flow. Conclusions Double inlet arterial graft systems supply the heart with larger graft flow than single inlet arterial graft systems. This benefit was obtained at the price of a longer duration of the operation, corresponding to the time it takes to harvest the right ITA.