Machine Perfusion Based Sub-normothermic Preservation of the Organs In-situ, in Block and Ex-vivo

Abstract

Introduction

Organ transplantation is multi-component treatment method. It has no alternative in irreversible diseases.  Its accompanied by many important issues, but the most discussed is - Organ Preservation . There are known a lot of methods of organs preservation were used.

The increasing demand for donor organs is forcing transplantologists to search for alternative approaches. Machine perfusion can be considered as one such approach.

At the Institute of Morphology, a number of perfusion machine models have been undergoing development since 2000. Representing miniature compact, portable versions of the heart-lung bypass machine. A cycle of experimental studies has been carried out with the presented machine:

        1. In the model of the animal with the cardiac arrest   artificial  heart-lung bypass was conducted in order to resuscitation.

        2. In case of liver autotransplantation, veno-venous shunting for hemodynamic protection of the recipient during the Ahepatic phase.

The aim of the study

 To assess the morphological state of liver after 7 –hour “in-situ” machine perfusion with pulsatile flow. To test the possibility of “ex vivo” preservation of hepato-renal block using machine perfusion with maintenance of physiological parameters.

Material and Methods

            “In situ” preservation of liver  was performed in 10 experimental animals. In all cases, the cardiac  arrest was remodeled, keeping the same duration of warm ischemia period. Duration of perfusion in this group was defined for 7 hours. Preservation was conducted under the systemic perfusion by constant and pulsatile flow (by own-desined pulsator).

In “ex-vivo” case the liver and kidney were removed together with the aorta and caudal vena cava on a common vascular pedicle. The perfusion was done through the aorta  and portal vein.

Results

Morphology study results of “in situ” liver preservation .

  Under non-pulsatile flow, after 7 hours of perfusion, the sd-MaS is diffuse. Ld-MaS is observed in 18% of liver tissue, singular necrotic areas.

  Pulsatile flow mode after 7 hours, Sd- MaS in 5%. Ld-MaS in 5% .

The results of 6-hour “ex-vivo” preservation : The dilatation of renal tubules and the wall thickness of several arteries were found. Mild mixed ld-MaS and sd-MaS were found in less than 10% of the hepatocytes.

These data are higher than at the perfusion starting but they continue to remain in the frame of standards suggested for the donor organs.

Conclusion

Thus, as a result of experiments, a portable perfusion device was developed, which provides optimal perfusion of an organ during systemic preservation with oxygenated blood, both for pulsatile arterial flow and for splanchnic flow in portal vein, as well as in situ multi-organ preservation in the donor organism.

Morphologic study results demonstrate the systemic sub-normothermic perfusion with perfusion machine successfully provides the liver preservation by continuous and pulsatile flow.

Liver is valid for transplantation. Pulsatile flow is confidently better.

The results of ex-vivo experiment of isolated liver and kidney indicate the possibility of further increase in duration of perfusion.