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.