Method and a system for prolongation of the viability of a donor organ
For post-mortem prolongation of the viability of an organ ( 7, 8, 50, 51 ) in a donor body, a flow of a solution is introduced from outside the body between a pair of barriers ( 21, 22 ) and a return flow including previously introduced quantities of the solution is led to the outside of the body. During a flushing phase, the flow including blood flushed out of the organ ( 7, 8, 50, 51 ) is discharged to a drain. Subsequently during a recirculation phase, solution returned from the body is cooled and/or oxygenated and recirculated from outside the body back into the body between the barriers. A system for carrying out the method is also described.
1. A method for prolongation of the viability of an organ in a deceased, donor body having a non-beating heart and blood conduits communicating with the organ to be transplanted, comprising:
introducing, while the organ is in the donor body and while the blood conduits are in communication with the organ, a flow of a solution from outside the body into a first one of the blood conduits of the body in a position upstream of the organ and between a first barrier and a second barrier closing off the first blood conduit;
leading a return flow including previously introduced quantities of the solution from a position in a second one of the blood conduits downstream of the organ to the outside of the body;
during a flushing, non-recirculating phase, cooling the organ and discharging the return flow returned outside the body to a drain, the return flow including blood flushed out of the organ;
subsequently, during a recirculation phase, at least oxygenating the solution returned from the body, and recirculating the returned solution from outside the body into the first blood conduit.
2. A method according to claim 1 , wherein
the organ is an abdominal organ;
the first blood conduit is an aorta, an artery branches off from the aorta to the organ, a vein communicates with the organ and the second blood conduit is a vena cava into which the vein communicating with the organ opens out;
the first barrier closes off the aorta at a side of the artery branching off to the organ remote from the heart or closes off the iliac and femoral arteries;
the second barrier closes off the aorta between the artery branching off to the organ and the heart; and
during the recirculation phase the solution returned from the vena cava, is at least oxygenated.
3. A method according to claim 1 , wherein
the organ is a lung;
the first blood conduit includes a right atrium or a right ventricle and the second blood conduit includes a left ventricle or the aorta;
the first barrier closes off the superior vena cava;
the second barrier closes off the inferior vena cava; and
during the recirculation phase, the solution returned from the left ventricle or the aorta, is at least cooled.
4. A method according to claim 1 , wherein the solution initially introduced before the start of the recirculation is a solution having a lower viscosity than the solution introduced during the recirculation.
5. A method according to claim 4 , wherein the solution initially introduced before the start of the recirculation is a solution having a lower starch concentration than the solution introduced during the recirculation.
6. A method according to claim 1 , wherein the oxygenation and recirculation of the extracted and oxygenated solution is started by operating a valve structure.
7. A method according to claim 1 , wherein the flow including the extracted and oxygenated solution that is recirculated is maintained at a flow rate of at least 200 ml/min.
8. A method according to claim 1 , wherein a pressure difference between the flow from outside the body into an area between said barriers and the flow to the outside of the body of at least 60 mmHG is maintained during recirculation.
9. A method according to claim 1 , further comprising filtering at least white blood cells and thrombi out of the solution before re-introduction of the solution into the body.
10. A method according to claim 1 , wherein, during the recirculation phase, the solution returned from the body is cooled before recirculation of the returned solution from outside the body into the first blood conduit.
11. A method according to claim 1 , wherein, during the recirculation phase, the recirculated solution comprises organ preservation liquid used during further preservation of the organ after explantation.
12. A system for prolongation of the viability of an organ while the organ is in a donor body, comprising:
a solution-feeding catheter for introduction into a first blood conduit of a human body upstream of the organ while the organ is in the donor body, the solution-feeding catheter having an outflow opening;
a return flow catheter for introduction into a second blood conduit of a human body downstream of the organ while the organ is in the donor body;
a drain conduit branching off from the return flow catheter;
a first barrier for closing off the first blood conduit on one side of the outflow opening and a second barrier for closing off the first blood conduit on an opposite side of the outflow opening;
a flushing solution supply conduit communicating with the solution-feeding catheter;
a pump communicating with the solution-feeding catheter and, in a flushing, non-recirculating operating condition, with a flushing solution reservoir and the drain conduit for discharging the return flow returned outside the body to a drain, and, in a recirculation operating condition, with the return flow catheter for recirculating solution returned via the return flow catheter; and
at least an oxygenator which, in the recirculation operating condition communicates with the return flow catheter, the pump and the solution-feeding catheter for at least oxygenating the solution in a flow pumped from the return catheter into the solution-feeding catheter.
13. A system according to claim 12 , comprising an oxygenator communicating with the return flow catheter for oxygenating the solution before recirculation into the body.
14. A system according to claim 12 , comprising a heat exchanger communicating with the return flow catheter for cooling the solution before recirculation into the body.
15. A system according to claim 14 , wherein the heat exchanger includes a conduit for the solution to be cooled and a cooling unit in heat exchanging contact with said conduit, and wherein the conduit is disconnectable from the cooling unit.
16. A system according to claim 12 , further comprising at least one valve communicating with the solution-feeding catheter, the return flow catheter, the drain conduit and the flushing solution supply conduit, the valve being arranged for switching between a flushing operating condition in which the return flow catheter communicates with the drain conduit and a recirculation operating condition, in which the return flow catheter communicates with the solution feeding catheter for recirculating solution returned via the return flow catheter.
17. A system according to claim 16 , wherein said at least one valve is operable for closing-off communication with the drain conduit and bringing the return flow catheter in communication with the solution feeding catheter, as a single operating step.
18. A system according to claim 12 , further comprising, in a conduit interconnecting the return flow catheter and the solution-feeding catheter, a filter for filtering out white blood cells and thrombi.
19. A system according to claim 12 , further comprising a container for transporting an organ, the container comprising conduits for recirculating a preservation liquid through the organ in the container, wherein at least a drive unit of the pump is connected or connectable to the container for driving the recirculation of the preservation liquid through the conduits.
20. A system according to claim 19 , wherein the pump comprises a drive unit and a liquid displacement unit communicating with said conduits of said container, the drive unit being releasably connected or releasably connectable to the displacement unit.