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Updated: Jul 29, 2026
Cardiopulmonary Bypass in a Mouse Model: A Novel Approach
Published on: September 22, 2017
The 'primeless pump': a novel technique for intraoperative blood conservation
J A Rousou1, R M Engelman, J E Flack
1Division of Cardiac Surgery, Baystate Medical Center, Springfield, Massachusetts 01107, USA.
Purpose:
Hemodilution during cardiopulmonary bypass may lead to anemia requiring intraoperative transfusions. Prime removal from the cardiopulmonary bypass circuit was used to limit dilution and intraoperative transfusions.
Methods:
The technique of prime removal consists of arterial and then venous side evacuation of crystalloid prior to cardiopulmonary bypass. The effectiveness of this technique, to maintain a higher hematocrit and reduce intraoperative transfusions, was studied prospectively in two consecutive groups of patients undergoing coronary revascularization (controls versus primeless).
Results:
Intraoperative hematocrits were significantly higher (P < 0.0001) and transfusions lower (4%) in the primeless versus the control group (19%) (P = 0.003). Prime removal is of particular benefit in anemic (hematocrit < or = 35%) and/or small patients (body surface area < or = 2 m2).
Conclusion:
The technique of prime removal is simple, safe and cost-effective, reducing intraoperative transfusions, especially in small and/or anemic patients. It could be part of blood conservation strategies in most adult cardiac operations.
