Flow capacity of inferior epigastric artery in composite arterial grafts

In the effort to expand the use of arterial conduits for myocardial revascularization, 'Y-graft' techniques are utilized with increasing frequency, although the physiology of this type of composite arterial grafts is not yet fully understood. The aim of this study was to measure changes in blood flow through a 'Y-graft' constructed by anastomosing a segment of inferior epigastric artery (IEA) off the side of an in situ internal thoracic artery (ITA).

Twenty-two patients who underwent CABG were enrolled in this prospective study. Exclusion criteria were age > 70 years, poor left ventricular function (Ejection Fraction < 0.25) and need for associated cardiac procedures. Blood flow in the TrA-IEA 'Y-graft' was measured in the operating room after completion of left ITA to left anterior descending artery (LAD) and IEA to marginal or diagonal branch anastomoses. Follow-up evaluation was performed at 3 and 12 months postoperatively.

After completion of surgery, blood flow in ITA and IEA as measured downstream from the Y anastomosis was 45+/-7 and 39+/-6 ml/min respectively. Temporary occlusion of either branch did not significantly affect flow in the other side of the arterial Y. All patients were discharged from the hospital in excellent condition. At follow-up no cases of angina recurrence were recorded.

Composite ITA-IEA arterial grafts provide excellent short-term clinical results. Blood flow on either side is not affected by run off in the other side branch. Information from this study may be used to understand the role that undivided ITA side branches play in reducing flow rate in an ITA graft harvested during minimally invasive CABG procedures.