Avoiding Secondary Hemodilution During Planned Temporary Right Ventricular Assist Device Implantation: An Autologous Priming Technique

Background: Temporary right ventricular assist device (RVAD) support is used during selected high-risk cardiac operations, including durable left ventricular assist device implantation, orthotopic heart transplantation, and procedures complicated by anticipated right ventricular failure. When RVAD implantation is planned during cardiopulmonary bypass (CPB), the RVAD circuit is commonly primed with crystalloid solution. Although 500-600 mL may appear modest in many adult patients, this secondary circuit prime may produce clinically meaningful hemodilution in patients who are frequently anemic, volume loaded, and near transfusion thresholds, where relatively small changes in hematocrit may alter clinical management. Technique: This report describes an autologous priming technique that uses patient blood available during CPB to displace crystalloid from the RVAD circuit before completion of the outflow connection. The technique requires no change to the conventional RVAD circuit, adds minimal time, and can be discontinued at any point if patient conditions do not safely permit further displacement. Discussion: This technique applies established autologous priming principles to a secondary extracorporeal circuit introduced after CPB has already been established. The objective is to avoid an unnecessary crystalloid load, minimize secondary hemodilution, and preserve hematocrit at the margin where transfusion decisions are commonly made. Conclusion: Autologous priming of the RVAD circuit during planned implantation is a simple, reproducible, patient-directed technique for minimizing secondary hemodilution while preserving conventional RVAD deployment.