Novel Post Mortal Organ Preserving ECMO in Non–Heart‐Beating Mouse

Objectives: Despite 100,000 organs transplanted yearly, there is up to several times more demand for organ donation. Critical demand for single- or multiple-organ donation and high mortality of patients being on the waiting list leads to search for alternate ways of organ source. Despite improved CPR strategy, survival rate after sudden cardiac arrest or stroke still varies from 5 to 10%. In almost all death cases, no organ preserving strategy is used or protocol exists. Nevertheless, CPR with routinized ECMO is being discussed. Therefore, the aim of our study was to develop a cadaveric ECMO based organ preservation after acute death in a non-heart-beating mouse model.

Methods: Acute death in C57Bl/6 mice was induced by cervical dislocation under isoflurane anesthesia. In 5 minutes after death 1,000 IU of heparin has been injected into jugular vein and indirect heart massage without ventilation was performed to reproduce a failed resuscitation. Then, animal body was cooled on ice, the non–heart-beating state was confirmed and left carotid artery and right jugular vein were cannulated. Ten milliliters of organ preservation mixture based on 4°C cold heparinized Krebs–Henseleit solution mixed with 1,000 IU of streptokinase based fibrinolytic agent had been given consecutively over both cannulas. The flushed blood was filtered using 100 µm membrane and collected for priming. The body was kept cooled to 6 to 8°C for 45 minutes. The ECMO circuit had priming volume of 0.6 mL + extra perfusion reservoir of 10 mL containing blood and mixture of Krebs–Henseleit and 6% HES solution in 1:1 v/v. The whole solution had calcium ions at the concentration of 2.25 µMol/L. In 1-hour after death, the animal body has been immersed in 37°C warm water and connected to the ECMO having heat exchanger. Oxygenator was supplied with pure oxygen at a flow of 0.5 L/min. Reperfusion was done at a flow of 3 to 5 mL/min.

Result: Immediate recovery in cardiac contraction and intestinal peristaltic have been observed. Despite developing tissue edema, heart function was present for > 4 hours. No post mortal contracture of body muscles has been observed during perfusion.

Conclusion: Immersion of the body into saline bath allowed fast rewarming of the body. Taking into consideration accelerated metabolism in mice, it can be supposed that few days of organ preserving ECMO perfusion of large animal or even human cadaver might be possible if appropriate solutions are used. Our protocol has a prospective potential to test different cell protective solutions for organ/body preservation in non–heart-beating small animal model.

Publication History

Article published online:
19 February 2021