Integrating Continuous Renal Replacement Therapy into Ex-situ Normothermic Liver Machine Perfusion.

Area of Science:

• Organ transplantation
• Machine perfusion technologies
• Renal replacement therapy

Background:

• Ex situ normothermic machine perfusion (NMP) supports liver graft viability but is limited by metabolic waste accumulation.
• Continuous renal replacement therapies (CRRT) can manage solute clearance and homeostasis.

Purpose of the Study:

• To describe a method for integrating continuous venovenous hemodiafiltration (CVVHDF) into ex situ liver NMP.
• To assess the impact of an independent filtration circuit on graft stability and function.

Main Methods:

• Described a protocol for connecting a CVVHDF circuit independently from the main liver NMP circuit.
• Detailed physical connection, priming, monitoring, and use of a Hoffman clamp for pressure simulation.
• Compared an out-of-circuit CVVHDF approach to direct in-line integration.

Main Results:

• The independent CVVHDF circuit configuration maintained hemodynamic stability and prevented excessive intravascular pressures.
• The out-of-circuit approach was associated with reduced graft edema compared to direct in-line integration.
• Stable circuit pressure and effective solute clearance were maintained.

Conclusions:

• Integrating CVVHDF independently into ex situ liver NMP is a safe and reproducible method.
• This approach enhances solute handling and prevents graft edema during extended perfusion.
• The method is adaptable to other perfusion systems to improve graft preservation.