Forty-one patients undergoing aortocoronary bypass surgery were divided into two groups: an "unclamped" group (17 patients) in whom the aorta was not cross-clamped during operation and a "clamped" group (24 patients) in whom the ascending aorta was cross-clamped during performance of distal anastomoses. Myocardial protection was provided during aortic clamping by cooling the anoxic heart with cold saline immersion. Immediate postoperative hemodynamic function was assayed in both groups, as was cardiopulmonary bypass time and cardiopulmonary bypass time/graft. Cardiopulmonary bypass time was 107 minutes in the unclamped group and 87 minutes in the clamped group (P less than 0.05). Cardiopulmonary bypass time/graft was 48 minutes in the unclamped group and 40 minutes in the clamped group (P less than 0.01). Results of hemodynamic studies with values for the unclamped group listed first were as follows: cardiac index (L/min/m2) 2.3 and 2.5 (NS), stroke index (ml/beat/m2) 23 and 25 (NS), left ventricular minute work index (kg-m/min/m2) 3.03 and 2.81 (NS), and stroke work index (g-m/min/m2) 31 and 30 (NS). These data indicate that aortic cross-clamping during performance of distal anastomoses expedites the performance of aortocoronary bypass surgery and does not adversely affect postoperative hemodynamics.
View details for PubMedID 1098807