ADVANTAGES OF CONTINUOUS NONCARDIOPLEGIC WARM BLOOD RETROGRADE PERFUSION OVER ANTEGRADE PERFUSION DURING PROXIMAL CORONARY ANASTOMOSES

Retrograde perfusion via the coronary sinus supplies vascular beds dis tal to coronary stenoses and has been used for administration of cardi oplegia. An additional application is to supply noncardioplegic retrog rade perfusion while performing proximal anastomoses (a time when card iac arrest is not critical). The aim of this study was to determine th e safety of this technique and to study the metabolic changes with ant egrade versus retrograde warm blood perfusion. Sixty-six patients, wit h good left ventricular function, underwent distal coronary bypass in a similar fashion. Proximal anastomoses were done with 1) partial occl usion clamp (n = 29) or 2) cross-clamp on and continuous, warm, noncar dioplegic retrograde blood perfusion (n = 37). In an additional 10 pat ients, metabolism was assessed with antegrade and retrograde perfusion during proximal anastomoses. Despite longer cross-clamp times (96.4 /- 6.2 vs 80.8 +/- 3.1 min, p < 0.05) with retrograde perfusion, the t otal duration of cardiopulmonary bypass was significantly less (119.6 +/- 6.2 vs 136.6 +/- 4.6 min, p < 0.05). There was superior postbypass , intraoperative hemodynamics (cardiac index) with retrograde perfusio n (4.0 +/- 0.2 vs 3.6 +/- 0.1 L/min/m2). The incidence of postoperativ e dysrhythmia was not significantly different between groups. Oxygen a nd glucose utilization was more efficient with retrograde perfusion. R etrograde perfusion during proximal anastomoses is a safe technique. T here is diminished risk of aortic dissection, antheroembolism, delayed aneurysm formation, or rupture due to avoidance of application of par tial occlusion clamps. There is evidence of superior substrate utiliza tion.