Comparison of Minimal Versus Conventional Extracorporeal Circulation in Coronary Surgery

We use a prototype AHEPA (modular type IV) circuit comprised of the standard and a standby accessory. Components of the standard circuit include: aortic cannula, three-stage venous cannula, coated tubing, a centrifugal pump, a new-generation membrane oxygenator with integrated arterial filter, a venous air removal device, a soft coated bag and pulmonary artery as well as aortic root vent. In addition, there is a standby hard-shell reservoir in parallel to the venous line, so as to convert the closed system to an open one. The standby component is bridged to the main circuit with an afferent line which is connected just before the VARD sending blood to the hard-shell reservoir and an efferent that re-directs it back to the VARD. A cell-saver device is added to the circuit for collecting shed blood and washing red blood cells for autotransfusion.

A standard open CPB circuit is used, consisting of uncoated PVC tubing, a hard-shell venous reservoir, a microporous membrane oxygenator (Dideco, Mirandola, Italy) and a roller pump (Stöckert S3, Munich, Germany). The circuit contains a 40 μm arterial line blood filter (Dideco, Mirandola, Italy) and it is primed with 1500 mL of a balanced crystalloid/colloid solution (1000 mL of Ringer's solution, 200 mL of mannitol 20%, and 300 mL of hydroxyethyl starch 6%). Cardiotomy as well as sump sucker are integrated to the circuit.