JP2023084756A - Organ preservation apparatus and organ preservation method - Google Patents

Abstract

To provide a technique capable of preserving an extracted organ in an excellent state, or recovering the state of an organ.SOLUTION: An organ preservation apparatus 1 comprises: an organ container 20; a liquid storage part 31; a liquid feed pipe 32 which supplies liquid from the liquid storage part 31 to an organ 9 in the organ container 20; and a pressure adjusting part 40 which adjusts the atmospheric pressure inside the organ container 20 to the pressure or less of the atmospheric pressure. The organ container 20 does not have a communication port to the outside other than a communication port 211 for allowing liquid to flow in to which the liquid feed pipe 32 is connected, and communication ports 221, 222, 223 for adjusting gas to which the pressure adjusting part 40 is connected. In the organ preservation apparatus 1, liquid can be smoothly supplied without applying pressure to blood vessels of the organ 9 by performing perfusion treatment while decompressing the organ container 20.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an organ preservation apparatus and an organ preservation method for perfusing an organ outside the body.

In organ transplantation surgery such as liver transplantation, the organ is temporarily preserved outside the body after the organ is removed from the donor until the organ is transplanted to the recipient. Various preservation methods and perfusion methods have been developed in order to preserve the excised organ in a transplantable state. For preserving an excised organ, for example, a simple cooling method is known in which the organ is immersed in a low-temperature preservative solution in order to suppress cell metabolism. In addition, a perfusion preservation method is known in which a perfusate is perfused through a blood vessel network in an organ for the purpose of removing waste products in the preserved organ. A conventional organ preservation device for perfusing an organ with a perfusate is described, for example, in US Pat.

JP 2020-90539 A

Before the simple cooling method or the perfusion preservation method, an initial perfusion treatment is performed to replace blood in the organ with an organ preservation solution or a perfusate. At this time, in organs removed from marginal donors, or in organs that have been in a warm ischemic state because treatment could not be performed immediately after removal, thrombosis occurs due to the deterioration of the intravascular condition. Flow path resistance may increase. In such a case, when liquid is supplied to the blood vessel of the organ in the initial perfusion treatment and the blood remaining inside is discharged, the organ may be burdened by the pressure of the liquid.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a technique capable of preserving an excised organ in good condition or restoring the condition of the organ.

In order to solve the above-mentioned problems, the first invention of the present application is an organ preservation apparatus for preserving an organ while perfusing the organ with a liquid outside the body, comprising: an organ container capable of containing the organ inside; a liquid reservoir for supplying the liquid from the liquid reservoir to the organ housed in the organ container, and adjusting the internal pressure of the organ container to be equal to or lower than the atmospheric pressure. The organ container has a liquid inflow communication port to which the liquid supply pipe is connected, and a gas adjustment communication port to which the pressure control unit is connected, and the The organ container does not have communication ports with the outside, except for the liquid inflow communication port and the gas adjustment communication port.

A second invention of the present application is the organ preservation apparatus according to the first invention, wherein in the initial perfusion treatment performed on the organ that has not been perfused after excision, the liquid discharged from the organ is stored in the organ. accumulate in the container.

A third invention of the present application is the organ preservation apparatus according to the first invention or the second invention, wherein the liquid is supplied from the liquid reservoir to the organ accommodated in the organ container by a difference in hydraulic head.

A fourth invention of the present application is an organ preservation method using the organ preservation apparatus according to any one of the first to third inventions, wherein the pressure in the organ container is adjusted to -10 mmHg or less by the pressure adjustment unit, and , -50 mmHg or higher, and a reduced pressure perfusion step of supplying the first liquid from the liquid reservoir to the blood vessel of the organ through the liquid supply tube.

A fifth invention of the present application is an organ preservation method for preserving an organ while perfusing the organ with a liquid outside the body, comprising: a) an organ containing step of containing the organ in a sealable organ container; and b) and a reduced-pressure perfusion step of supplying the first liquid to the blood vessel of the organ while maintaining the air pressure inside the organ container at −10 mmHg or less and −50 mmHg or more.

A sixth invention of the present application is the organ preservation method according to the fifth invention, wherein the first liquid is transferred from the liquid reservoir in which the first liquid is reserved to the organ accommodated in the organ container due to a difference in water head. of liquid is supplied.

The seventh invention of the present application is the organ preservation method of the fifth invention or the sixth invention, wherein in the step a), the organ that has not been perfused after being excised from the body of the donor is housed, and In b), the first liquid is a liquid other than blood.

The eighth invention of the present application is the organ preservation method of the seventh invention, further comprising c) a simple cooling preservation step of immersing the organ in a second liquid of 10° C. or lower after the step b).

A ninth invention of the present application is the organ preservation method according to any one of the fifth invention to the eighth invention, wherein in the step b), the temperature of the first liquid is 10° C. or lower.

According to the first to fourth inventions of the present application, an organ can be accommodated in an airtight organ container, and perfusion treatment can be performed with the pressure inside the organ container set to a pressure equal to or lower than the atmospheric pressure. As a result, the liquid can be smoothly supplied to the blood vessels in the organ while reducing the burden on the organ. As a result, the excised organ can be preserved in good condition, or the condition of the organ can be restored.

In particular, according to the second invention of the present application, since the organ container does not have a through-hole for liquid discharge, the organ container is more airtight.

In particular, according to the third invention of the present application, it is possible to suppress the increase in the pressure applied to the organ housed in the organ container as compared with the case where the liquid is supplied using the pump.

In particular, according to the fourth invention of the present application, fluid is smoothly supplied to the blood vessels of the organ while suppressing an increase in pressure applied to the blood vessels of the organ and suppressing damage to the organ due to negative pressure. be able to.

According to the fifth to ninth inventions of the present application, the pressure applied to the blood vessels of the organs is suppressed from increasing, and the damage to the organs due to the negative pressure is suppressed, while the liquid is smoothly introduced into the blood vessels of the organs. can supply.

In particular, according to the sixth invention of the present application, it is possible to suppress the increase in the pressure applied to the organ housed in the organ container as compared with the case where the liquid is supplied using the pump.

In particular, according to the seventh invention of the present application, even when the flow path resistance in the blood vessel is increased due to thrombus or the like in the initial perfusion treatment (flush treatment) of the organ, the pressure applied to the blood vessel of the organ is prevented from increasing. It is possible to smoothly supply liquid to the blood vessels of the organ while suppressing the negative pressure and suppressing damage to the organ due to the negative pressure.

In particular, according to the eighth invention of the present application, the organ can be preserved by simple cooling preservation after the initial perfusion treatment.

It is the figure which showed the structure of the organ preservation apparatus. 2 is a flow chart showing the flow of preservation processing from organ extraction to transplantation. 4 is a flow chart showing the flow of initial perfusion processing. It is the figure which showed the experimental result of the 1st experiment. It is the figure which showed the measurement result of the time series in the 2nd experiment. FIG. 10 is a diagram showing the relationship between the pressure inside the organ container and the inflow of perfusate in the second experiment. It is the figure which showed the experimental result in the 3rd experiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As used herein, "donors" and "recipients" may be human or non-human animals. That is, in the present application, an "organ" may be either a human organ or a non-human animal organ. Non-human animals may also be rodents, including mice and rats; ungulates, including pigs, goats, and sheep; non-human primates, including chimpanzees; Animals other than animals may be used.

<1. Configuration of Organ Preservation Apparatus>
FIG. 1 is a diagram showing the configuration of an organ preservation apparatus 1 according to one embodiment.

This organ preservation apparatus 1 is an apparatus for temporarily preserving an organ 9 removed from a donor outside the body during an organ transplant operation until the organ is transplanted to a recipient. Examples of organs 9 include liver, kidney, heart, and pancreas. However, the organ 9 preserved in the organ preservation apparatus 1 may be another organ or a part of the organ. The organ preservation apparatus 1 preserves the organ 9 while perfusing the blood vessels inside the organ 9 with a liquid such as physiological saline, an organ preservation solution, or a perfusate.

As shown in FIG. 1, the organ preservation apparatus 1 of this embodiment includes an organ container 20, a liquid supply section 30, a pressure adjustment section 40, and a control section .

The organ container 20 is a storage container that stores a biological sample such as an excised organ. The organ container 20 has a container body portion 21 and a container lid portion 22 . The container main body 21 is a cup-shaped member that opens upward. The container lid portion 22 is a member that covers the upper opening of the container body portion 21 . The container body portion 21 and the container lid portion 22 are made of resin, for example.

A packing 23 having elasticity is arranged at a connecting portion between the container main body portion 21 and the container lid portion 22 . The packing 23 is arranged along the entire circumference of the edge of the opening of the container main body 21 . When the container body 21 and the container lid 22 are fixed by a plurality of (two in this embodiment) hooks 220 provided on the container lid 22, the organ container 20 is hermetically sealed. Note that the number of hooks 220 may be three or more. Moreover, the mechanism for sealing the container body 21 and the container lid 22 is not limited to the packing 23 and the hook 220, and other structures may be used.

As shown in FIG. 1, the container main body 21 is provided with a liquid inflow communication port 211 . The liquid inflow communication port 211 penetrates the side wall of the container main body 21 in the horizontal direction, and can be connected to a pipe such as a catheter from the inside and outside of the container main body 21 .

Further, the container lid portion 22 is provided with a first gas adjustment communication port 221 , a second gas adjustment communication port 222 , and a third gas adjustment communication port 223 . The three gas adjustment communication ports 221, 222, and 223 respectively penetrate the container lid portion 22 in the vertical direction.

Note that the organ container 20 does not have communication ports with the outside, except for the liquid inflow communication port 211 and the three gas adjustment communication ports 221 , 222 , and 223 .

In this embodiment, when the organ 9 is accommodated inside the organ container 20 , the organ 9 is placed on the organ holder 24 arranged inside the organ container 20 . Note that the organ 9 may be placed directly on the bottom of the container main body 21 .

The organ holder 24 holds the organ 9 inside the organ container 20 . The organ holding section 24 has a flexibly deformable holding sheet 241 and a support member 242 . An end portion of the holding sheet 241 is supported by a support member 242 fixed to the bottom surface of the container main body 21 . As a result, the holding sheet 241 is kept open substantially horizontally. When the organ 9 is placed, the holding sheet 241 deforms along the surface shape of the organ 9 . As a result, deformation of the organ 9 can be suppressed, and the organ 9 can be held while reducing the burden on the organ 9 . Note that the organ holder 24 may have other configurations.

The liquid supply unit 30 supplies the preservation liquid to the organ 9 . The liquid supply section 30 has a liquid storage section 31 and a liquid supply pipe 32 .

The liquid storage part 31 holds a preservation liquid before being supplied to the organ 9 . The liquid storage part 31 of the present embodiment is a pouch bag (so-called drip bag) in which a preservation liquid is stored. It should be noted that the liquid storage part 31 may be in other forms such as a so-called tank or bottle as long as it is a container capable of storing the preservation liquid. The liquid storage part 31 is held at a position higher than the organ 9 held in the organ container 20 by the bag holding part 33 .

The liquid supply pipe 32 is a pipe for supplying preservation liquid from the liquid reservoir 31 to the organ 9 held in the organ container 20 . In this embodiment, the liquid supply pipe 32 consists of a first liquid supply pipe 321 and a second liquid supply pipe 322 .

The upstream end of the first liquid supply pipe 321 is connected to the liquid reservoir 31 . The downstream end of the first liquid supply pipe 321 is detachably connected to the liquid inflow communication port 211 provided in the container body 21 from the outside of the container body 21 . A so-called drip tube (drip chamber) 323 and an on-off valve 324 are inserted in the first liquid supply pipe 321 . The on-off valve 324 opens and closes communication of the first liquid supply pipe 321 . Note that the first liquid supply pipe 321 may not have the drip tube 323 . Also, instead of the on-off valve 324, a flow rate regulator (roller clamp, clamp) used in a general infusion device may be used.

The second liquid supply tube 322 is a catheter whose one end is connected to the artery of the organ 9 . The upstream end of the second liquid supply pipe 322 is detachably connected to the liquid inflow communication port 211 provided in the container body 21 from the inside of the container body 21 . The downstream end of the second liquid supply pipe 322 is connected to the artery of the organ 9 .

The downstream end of the first liquid supply pipe 321 is connected to the liquid inflow communication port 211 from the outside, and the upstream end of the second liquid supply pipe 322 is connected to the liquid inflow communication port 211 from the inside. Then, the first liquid supply pipe 321 and the second liquid supply pipe 322 communicate with each other. As a result, a flow path for the preservation liquid flowing from the liquid reservoir 31 to the organ 9 via the first liquid supply pipe 321 , the liquid inflow communication port 211 , and the second liquid supply pipe 322 is formed.

In this embodiment, no liquid supply pump is provided on the route of the liquid supply pipe 32 . Due to the difference in water head between the liquid reservoir 31 and the organ 9 , the preservation liquid flows from the liquid reservoir 31 through the liquid supply pipe 32 into the artery of the organ 9 . In this way, by omitting the liquid supply pump, it is possible to simplify the device configuration and reduce the pressure burden on the organ 9 due to the inflow of the preservation liquid.

The pressure adjustment unit 40 is arranged outside the organ container 20 and adjusts the pressure inside the organ container 20 to be equal to or lower than the atmospheric pressure. The pressure adjustment unit 40 has a decompression mechanism 41 , a pressure measurement unit 42 and a leak valve 43 .

The decompression mechanism 41 of this embodiment includes an intake pipe 411 , a decompression pump 412 , a regulator 413 and an on-off valve 414 .

An upstream end portion of the intake pipe 411 is detachably connected to the first gas adjustment communication port 221 provided in the container lid portion 22 . As a result, the upstream end of the intake pipe 411 communicates with the internal space of the organ container 20 . A downstream end of the intake pipe 411 is connected to a decompression pump 412 . Regulator 413 and open/close valve 414 are provided on the path of intake pipe 411 . Accordingly, when the decompression pump 412 is operated, gas is sucked from the internal space of the organ container 20 through the suction pipe 411 and discharged to the external space. As a result, the air pressure inside the organ container 20 is lowered. The regulator 413 boosts the negative pressure generated by the decompression pump 412 to a higher constant negative pressure (smaller absolute value when expressed in gauge pressure). The opening/closing valve 414 is a valve for switching the airflow in the intake pipe 411 between an open state and a stopped state. In place of the decompression pump 412, a utility for decompression provided outside the organ storage container 1 may be used.

The pressure measurement unit 42 measures the pressure inside the organ container 20 . The pressure measurement unit 42 is connected to the second gas adjustment communication port 222 .

The leak valve 43 is connected to the third gas adjustment communication port 223 . The leak valve 43 introduces gas into the organ container 20 from the external space when the pressure inside the organ container 20 becomes equal to or lower than a predetermined pressure. On the other hand, the leak valve 43 closes the third gas adjustment communication port 223 when the pressure inside the organ container 20 is higher than the predetermined pressure. In this embodiment, the leak valve 43 introduces gas into the organ container 20 from the external space when the pressure inside the organ container 20 becomes -50 mmHg or less.

The control unit 10 is means for controlling the operation of the pressure adjustment unit 40 . The control unit 10 is configured by, for example, an electronic circuit board or a computer including a processor such as a CPU and a memory such as a RAM. The control unit 10 is also electrically connected to the decompression pump 412, the regulator 413 and the on-off valve 414 of the decompression mechanism 41, and the pressure measurement unit 42, respectively. The control unit 10 controls the operation of each unit of the decompression mechanism 41 according to the pressure inside the organ container 20 measured by the pressure measurement unit 42 based on a preset program. Thereby, the air pressure inside the organ container 20 is adjusted.

<2. Flow of Preservation Processing from Organ Extraction to Transplantation>
Next, an example of a procedure for preserving the organ 9 will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is a flow chart showing the flow of preservation processing from extraction of the organ 9 to transplantation. FIG. 3 is a flow chart showing the flow of initial perfusion processing using the organ preservation apparatus 1 of the above embodiment.

As shown in FIG. 2, first, an organ 9 is extracted from a donor, and a second liquid supply tube 322 (catheter) is connected to the organ 9 (step S1). Specifically, first, the surgeon cuts the artery of the organ 9 and connects the downstream end of the second liquid supply tube 322 (catheter) to the cut portion of the artery. Also, the surgeon cuts the veins of the organ 9 and separates the organ 9 from the donor. Then, the organ 9 is taken out from the body of the donor. The process of connecting the second liquid supply pipe 322 to the organ 9 is part of the preparation for the subsequent initial perfusion process.

Next, an initial perfusion process using the organ preservation apparatus 1 is performed (step S2). The initial perfusion treatment is a perfusion treatment performed on an organ that has not been subjected to perfusion treatment after removal from the donor's body. In this initial perfusion process, the blood vessels of the organ 9 are supplied with the first liquid while the pressure inside the organ container 20 is kept at −10 mmHg or less and −50 mmHg or more.

The first liquid is a liquid other than blood. The first liquid is, for example, a perfusate (mixture of physiological saline and ETK liquid). The first liquid may be physiological saline, a perfusate such as an ETK liquid or a UW liquid, or a mixture thereof.

Also, the temperature of the first liquid is preferably 0° C. or higher and 10° C. or lower. Specifically, the temperature of the first liquid is more preferably about 4° C. (3° C. or more and 5° C. or less). By making the first liquid supplied to the organ 9 at such a low temperature in the initial perfusion treatment, it is possible to suppress the metabolism of the organ 9 and suppress the production of waste products in the organ.

In the initial perfusion process in step S2, as shown in FIG. 3, first, the organ preservation apparatus 1 is prepared (step S21). It should be noted that the preparatory step of step S21 is preferably performed before the extraction of the organ in step S1.

Specifically, the container lid portion 22 is removed from the container body portion 21 and the organ holding portion 24 is arranged inside the container body portion 21 . The upstream end of the first liquid supply pipe 321 is connected to the liquid reservoir 31 , and the downstream end of the first liquid supply pipe 321 is connected to the liquid inflow communication port 211 . At this time, the on-off valve 324 is closed to stop the first liquid from flowing out from the downstream end of the first liquid supply pipe 321 . Furthermore, each part of the pressure adjustment part 40 is connected to the three gas adjustment communication ports 221 , 222 , 223 .

Subsequently, the organ 9 is housed in the sealable organ container 20 (step S22: organ housing step). Specifically, the organ 9 is placed on the organ holding portion 24 arranged inside the container body portion 21 . Then, the upstream end of the second liquid supply pipe 322 is connected to the liquid inflow communication port 211 . As a result, the first liquid can be supplied from the liquid reservoir 31 to the artery of the organ 9 via the first liquid supply pipe 321 , the fluid inflow communication port 211 and the second supply pipe 322 . On the other hand, the cut portion of the vein of the organ 9 is not blocked and is not connected to a catheter or the like. Thereafter, the container lid portion 22 is attached to the container main body portion 21 and fixed by the hooks 220 to close the internal space of the organ container 20 .

After the organ 9 is accommodated, the control unit 10 operates the pressure adjustment unit 40 to start reducing the pressure in the organ container 20 (step S23). Specifically, the decompression pump 412 and the regulator 413 are operated, and the open/close valve 414 is opened. As a result, the pressure inside the organ container 20 gradually approaches the set pressure (negative pressure) from the atmospheric pressure. For example, the pressure setting is -40 mmHg.

In the initial perfusion treatment, the pressure inside the organ container 20 is preferably −10 mmHg or less and −50 mmHg or more. By setting the pressure in the organ container 20 to −10 mmHg or less, the blood vessels in the organ 9 are more likely to expand than when the organ 9 is under atmospheric pressure, and when the first liquid is supplied to the blood vessels, , the pressure on the blood vessels is reduced. Therefore, the first liquid can be smoothly supplied to the blood vessels of the organ 9 while reducing the burden on the organ 9 . On the other hand, when the atmospheric pressure around the organ 9 is less than -50 mmHg, the organ 9 is likely to edema. Therefore, it is preferable that the pressure inside the organ container 20 is -50 mmHg or higher.

Further, in the initial perfusion treatment, the pressure inside the organ container 20 is more preferably −30 mmHg or less and −50 mmHg or more. By setting the pressure in the organ container 20 to −30 mmHg or less, the blood vessels in the organ 9 are more easily expanded than when the organ 9 is under atmospheric pressure, and when the first liquid is supplied to the blood vessels Additionally, there is less pressure on the blood vessels.

After the pressure inside the organ container 20 reaches a desired range, the supply of the first liquid to the organ 9 is started (step S24: decompression perfusion step). Specifically, the on-off valve 324 is opened, and the supply of the first liquid from the liquid reservoir 31 to the organ 9 by the head difference is started. Here, the desired range is, for example, −35 mmHg or less and −45 mmHg or more.

When the first liquid is supplied to the organ 9 , the blood remaining in the blood vessels of the organ 9 and the first liquid that has passed through the blood vessels of the organ 9 are discharged from the veins of the organ 9 . Since the cut portion of the vein of the organ 9 is not blocked and the vein is not connected to a catheter or the like, the discharged blood and the first liquid accumulate in the organ container 20 .

When the first liquid stored in the liquid storage part 31 is completely discharged, the supply of the first liquid to the organ 9 is finished (step S25). This completes the initial perfusion process in step S2. In this embodiment, the first liquid stored in the liquid storage section 31 is 200 mL. Therefore, about 200 mL of the first liquid is supplied to the organ 9 in the depressurized perfusion step of step S24.

In this embodiment, a predetermined amount of the first liquid stored in the liquid storage section 31 is supplied to the organ 9 . However, the initial perfusion treatment may not supply a predetermined amount of liquid, but rather supply liquid for a predetermined period of time.

In this way, by performing the initial perfusion treatment with the pressure in the organ container 20 containing the organ 9 set to -10 mmHg or less -50 mmHg or more, when the flow path resistance in the blood vessel of the organ 9 is large due to the occurrence of thrombus, etc. Even so, the flow path resistance in the blood vessel can be reduced, and the first liquid can be smoothly supplied into the blood vessel. As a result, the blood remaining in the organ 9 can be discharged and replaced with the first liquid while suppressing the burden on the organ 9 . As a result, the excised organ 9 can be preserved in good condition, or the condition of the organ 9 can be restored.

After the initial perfusion process in step S2 is completed, simple cooling process is performed on the organ 9 (step S3). In this simple cooling process, the organ 9 is immersed in a second liquid of 10° C. or less (approximately 4° C. in this embodiment). Specifically, the organ 9 is taken out from the organ container 20, placed in a cooling container capable of keeping cold, together with the second liquid, and the organ 9 is immersed in the second liquid. Then, the temperature in the cooling container, that is, the temperature of the organ 9 and the second liquid is kept at about 4°C. Note that the organ container 20 used in the initial perfusion process in step S2 may be used as the cooling container.

The second liquid is a liquid other than blood. The second liquid is, for example, a perfusate (ETK liquid). The second liquid may be physiological saline, a perfusion liquid such as an ETK liquid or a UW liquid, or a mixture thereof.

Also, the temperature of the first liquid is preferably 0° C. or higher and 10° C. or lower. Specifically, the temperature of the first liquid is more preferably about 4° C. (3° C. or more and 5° C. or less). In the simple cooling treatment, by making the liquid in which the organ 9 is immersed at such a low temperature, it is possible to suppress the metabolism of the organ 9 and suppress the production of waste products in the organ.

The simple cooling treatment in step S3 may be performed for a predetermined period (for example, 1 hour), or the organ 9 subjected to the initial perfusion treatment in step S2 after extraction from the donor is transported to the recipient side. It may be done during the

<3. Experiment results>
Subsequently, the following three types of experiments were conducted with respect to the organ preservation method using the organ preservation apparatus 1 of this embodiment.

<3-1. First experiment/preliminary verification experiment>
(Experimental target)
Porcine kidney negative pressure 0 mmHg group: N = 1
Negative pressure -30 mmHg group: N = 1
Negative pressure -50 mmHg group: N = 1
(experimental protocol)
Using the organ preservation apparatus 1 of the above-described embodiment, the pressure in the organ container 20 is set to negative pressure, the liquid is supplied to the artery of the kidney using the hydraulic head difference, and the time until the supply of 200 mL of liquid is completed (perfusion time) was measured. Also, the average perfusion rate was calculated from the perfusion time. The experiment was conducted with three pressures, 0 mmHg, −30 mmHg, and −50 mmHg, in the organ container 20 .

(Experimental result)
FIG. 4 is a diagram showing experimental results of the first experiment. As shown in FIG. 4, when the pressure inside the organ container 20 was −30 mmHg and −50 mmHg, the perfusion time was less than half that when the pressure inside the organ container 20 was 0 mmHg. That is, when the pressure inside the organ container 20 was −30 mmHg and −50 mmHg, the average perfusion amount was more than doubled in the liquid supply due to the head difference compared to when the pressure inside the organ container 20 was 0 mmHg.

From this, when the pressure inside the organ container 20 is −30 mmHg and −50 mmHg, the flow path resistance of the blood vessel in the kidney becomes smaller than when the pressure inside the organ container 20 is 0 mmHg, and the blood vessel flows smoothly. It is believed that a liquid can flow through it.

<3-2. Second Experiment/Preliminary Verification Experiment>
(Experimental target)
Porcine kidney (experimental protocol)
Using the organ preservation apparatus 1 of the above-described embodiment, the organ preservation apparatus 1 of the above-described embodiment is used to supply a 4° C. perfusate (mixed solution of physiological saline and ETK solution) to the porcine kidney immediately after the excision. The pressure inside the container 20 was changed, and the intra-arterial pressure and the inflow of the perfusate into the renal artery were measured. Specifically, the pressure inside the organ container 20 was gradually reduced from approximately 0 mmHg to approximately −290 mmHg, and then gradually increased from approximately −290 mmHg to approximately 0 mmHg. The leak valve 43 was removed and the third gas adjustment communication port 223 was airtightly closed so that the pressure inside the organ container 20 could be less than -50 mmHg.

(Experimental result)
FIG. 5 is a diagram showing time-series measurement results in the experiment. The upper part of FIG. 5 is a diagram showing changes in time series of the pressure inside the organ container 20 (chamber internal pressure). The middle part of FIG. 5 is a diagram showing time-series changes in renal intra-arterial pressure (arterial pressure). The lower part of FIG. 5 shows changes in the inflow (flow rate) of the perfusate over time. FIG. 6 is a diagram showing the relationship between the pressure inside the organ container 20 and the inflow of perfusate in the experimental results of FIG.

As shown in FIG. 5, when the pressure inside the organ container 20 is lowered while the perfusate is being supplied (when negative pressure is applied), the pressure in the artery decreases and the flow rate of the perfusate increases. Further, when the pressure inside the organ container 20 is increased while supplying the perfusate (at the time of negative pressure release), the intra-arterial pressure rises and the flow rate of the perfusate decreases as the pressure rises.

Immediately after the start of the supply of the perfusate, the intra-arterial pressure temporarily increased and the flow rate of the perfusate decreased. It is thought that the influx of the artery temporarily contracted the artery, increased the intra-arterial pressure, and increased the flow resistance in the artery.

As shown in FIG. 6, both when the negative pressure is applied and when the negative pressure is released, there is no large hysteresis, and the lower the pressure inside the organ container 20 (chamber pressure), the more the inflow of the perfusate. The relationship that (flow rate) is large became clear.

<3-3. Third experiment>
(Experimental target)
Porcine kidney control group: N=2
Reduced pressure initial perfusion group: N=4
(experimental protocol outline)
(1) Warm ischemic period (2) Initial perfusion treatment (3) Simple cold storage treatment (4) Normal temperature reperfusion treatment

(experimental protocol)
(1) Warm ischemic period The renal artery was clamped in the body of a cardiac arrest donor (pig) to stop blood circulation to the kidney for 60 min. The kidney was then removed from the donor.

(2) Initial Perfusion Treatment 200 mL of a perfusate (mixed solution of physiological saline and ETK solution) at about 4° C. was supplied to the kidney immediately after the excision. The perfusate was supplied to the kidney through a catheter connected to the artery and discharged naturally from the vein. In this initial perfusion treatment, in the control group, the kidney was placed in an open container without a lid, and the same liquid supply unit 30 as in the organ preservation apparatus 1 was used to supply the perfusate. On the other hand, in the reduced-pressure initial perfusion group, the organ preservation apparatus 1 of the present embodiment was used, and the perfusate was supplied with the pressure inside the organ container 20 set to -40 mmHg.

(3) Simple Cooling Preservation Treatment The kidneys after the initial perfusion treatment were immersed in a preservation solution (ETK solution) at about 4° C. for 60 minutes.

(4) Normal temperature reperfusion treatment Kidneys that had undergone simple cold storage treatment were perfused with leukocyte-free donor blood (whole blood) at about 37°C for 30 minutes. This simulated the state after being transplanted to the recipient. Donor blood was supplied to the kidney through a catheter connected to an artery, and the blood naturally discharged from the vein was recovered and supplied to the kidney again in a recirculation system.

In the above procedure, the perfusate flow rate and renal arterial pressure were measured in the initial perfusion treatment. In addition, the weight of the kidney was measured three times immediately after extraction, immediately after the end of the initial perfusion treatment, and immediately after the end of the normal temperature reperfusion treatment. In addition, a pathological examination was performed on each kidney after completion of normal temperature reperfusion treatment.

(Experimental result)
FIG. 7 is a diagram showing experimental results in the experiment. The upper part of FIG. 7 shows the average maximum flow rate of the perfusate and the average maximum arterial pressure in the initial perfusion treatment. The lower part of FIG. 7 shows the rate of weight increase in comparison immediately after the end of the initial perfusion treatment and immediately after extraction in the normal temperature reperfusion treatment.

As shown in the upper part of FIG. 7, in the reduced-pressure initial perfusion group, the maximum flow rate of the perfusate is higher than that in the control group, although the arterial pressure is about the same. As a result, in the reduced-pressure initial perfusion group, the pressure in the organ container 20 is set to a negative pressure within a predetermined range in the initial perfusion treatment, so that the perfusate is smoothly distributed without increasing the pressure applied to the arteries of the organs 9. It can be seen that it can be supplied to

In addition, as shown in the lower part of FIG. 7, in both the control group and the reduced-pressure initial perfusion group, a weight increase of 1.9% was observed immediately after the initial perfusion treatment compared to immediately after extraction. Immediately after the end of the normal temperature reperfusion treatment, the control group showed a further weight increase of 2.7%, whereas the reduced pressure initial perfusion group showed a weight decrease of -5.8%, which was lower than immediately after the extraction. there is

This shows that in the control group, edema occurs in the warm-ischemic kidney after initial perfusion, cold storage, and normal-temperature reperfusion, which is a pseudo-transplantation. On the other hand, in the reduced-pressure initial perfusion group, although a slight weight increase was temporarily observed immediately after the initial perfusion treatment, edema improved after the cold storage treatment and normal temperature reperfusion treatment. Therefore, it can be said that the edema of the organ 9 can be suppressed by setting the pressure inside the organ container 20 to a negative pressure within a predetermined range in the initial perfusion treatment.

In addition, the results of pathological examination showed that both values indicating medulla congestion and edema in the reduced-pressure initial perfusion group were significantly lower than those in the control group.

<3-4. Other Experiments and Considerations from Experiments>
In addition, experiments similar to Experiment 1 were conducted on porcine kidneys by setting the pressure inside the organ container 20 to various values. Then, the weight of the organ 9 was measured before and after the perfusion treatment in order to confirm whether or not edema occurred. As a result, it was found that edema may occur (ie, after perfusion) when the lowest pressure value (the pressure value with the largest absolute value of negative pressure) during perfusion exceeds −50 mmHg.

On the other hand, from Experiments 1 and 2, the lower the pressure inside the organ container 20 during the perfusion treatment, the lower the flow resistance of the blood vessels inside the organ 9, and the less the damage to the organ 9 due to the pressure increase inside the blood vessels. I understand. Further, according to Experiment 3, by setting the pressure inside the organ container 20 to a negative pressure in the initial perfusion treatment, the perfusate can be supplied smoothly without increasing the pressure applied to the artery, and edema can be suppressed. know that you can.

In view of these circumstances, by setting the pressure in the organ container 20 to -10 mmHg or less and -50 mmHg or more in the initial perfusion treatment, even organs in relatively poor conditions such as warm ischemic conditions It was found that the cells can be preserved in a state suitable for transplantation.

<4. Variation>
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

In the above embodiment, the liquid discharged from the organ 9 is stored in the organ container 20 in the organ preservation apparatus 1 for performing the initial perfusion treatment, but the present invention is not limited to this. The organ preservation apparatus 1 may include a liquid recovery section that recovers the liquid accumulated in the organ container 20 from the lower portion of the organ container 20 and returns it to the liquid storage section 31 .

Further, in the above-described embodiment, the initial perfusion treatment is performed under a reduced pressure environment, and then the simple cooling preservation treatment is performed, but the present invention is not limited to this. Instead of the simple cold preservation treatment, a perfusion treatment under conditions different from the initial perfusion treatment (hereinafter referred to as "subsequent perfusion treatment") may be performed. The subsequent perfusion treatment may be performed using the same organ preservation device 1 as the initial perfusion treatment, or may be performed using a different organ preservation device.

Further, in the subsequent perfusion process, for example, the organ 9 may be perfused under atmospheric pressure. Alternatively, in the subsequent perfusion treatment, the perfusion treatment may be performed at a negative pressure closer to atmospheric pressure than the negative pressure in the initial perfusion treatment. Specifically, the pressure inside the organ container 20 in the initial perfusion treatment may be -30 mmHg or less -50 mmHg or more, and the pressure in the organ container 20 in the subsequent perfusion treatment may be 0 mmHg or less -30 mmHg or more. In the subsequent perfusion process after blood containing thrombus is discharged from the organ 9 in the initial perfusion process, it is not necessary to set the negative pressure as large as in the initial perfusion process. On the other hand, by setting the pressure to a negative pressure lower than the atmospheric pressure, it is possible to smoothly supply the perfusate to the organ 9 in the subsequent perfusion treatment as compared to the case under the atmospheric pressure.

Also, the detailed structure of the organ preservation device does not have to completely match the structure shown in each figure of the present application. Also, the elements appearing in the above embodiments and modified examples may be appropriately combined within a range that does not cause contradiction.

1 organ preservation device 9 organ 20 organ container 31 liquid reservoir 32 liquid supply tube 40 pressure adjustment section 211 liquid inflow communication port 221, 222, 223 gas adjustment communication port 321 first liquid supply pipe 322 second liquid supply pipe

Claims (9)

An organ preservation device for preserving an organ while perfusing the organ with a liquid outside the body,
an organ container capable of accommodating an organ therein;
a liquid storage part in which the liquid is stored;
a liquid supply pipe that supplies the liquid from the liquid reservoir to the organ accommodated in the organ container;
a pressure adjustment unit that adjusts the internal pressure of the organ container to a pressure equal to or lower than the atmospheric pressure;
with
The organ container is
a liquid inflow communication port to which the liquid supply pipe is connected;
a gas adjustment communication port to which the pressure adjustment unit is connected;
has
The organ storage apparatus according to claim 1, wherein the organ container does not have a communication port with the outside except for the liquid inflow communication port and the gas adjustment communication port. The organ preservation device according to claim 1,
An organ preservation apparatus, wherein the liquid discharged from the organ accumulates in the organ receptacle in the initial perfusion treatment performed on the organ that has not been subjected to post-excision perfusion treatment. The organ preservation device according to claim 1 or claim 2,
The organ preservation apparatus, wherein the liquid is supplied from the liquid reservoir to the organ accommodated in the organ container by a hydraulic head difference. An organ preservation method using the organ preservation apparatus according to any one of claims 1 to 3,
The first liquid is supplied from the liquid reservoir to the blood vessels of the organ through the liquid supply pipe while the pressure in the organ container is adjusted to −10 mmHg or less and −50 mmHg or more by the pressure adjustment unit. A method for preserving an organ, comprising a reduced-pressure perfusion step. An organ preservation method for preserving an organ while perfusing the organ with a liquid outside the body,
a) an organ containing step of containing said organ in a sealable organ container;
b) a reduced pressure perfusion step of supplying a first liquid to a blood vessel of the organ while maintaining the pressure inside the organ container at −10 mmHg or less and −50 mmHg or more;
A method for preserving organs. The organ preservation method according to claim 5,
The organ preservation method, wherein the first liquid is supplied from a liquid reservoir in which the first liquid is reserved to the organ accommodated in the organ container due to a hydraulic head difference. The organ preservation method according to claim 5 or 6,
In the step a), housing the organ that has not been perfused after being removed from the body of the donor,
The organ preservation method, wherein in the step b), the first liquid is a liquid other than blood. The organ preservation method according to claim 7,
c) A method for preserving an organ, further comprising, after the step b), a simple cooling preservation step of immersing the organ in a second liquid of 10°C or lower. The organ preservation method according to any one of claims 5 to 8,
The organ preservation method, wherein in the step b), the temperature of the first liquid is 10° C. or lower.

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