Donor organ preservation method and donor organ preservation container

Abstract

The group of inventions relates to methods and devices for preserving donor organs and can be used in the medical sector, particularly in organ transplantation. The essence of the group of inventions lies in a method of preserving a donor organ which is carried out using a container for preserving a donor organ, wherein an organ is placed into the interior cavity of said container and coupled to a perfusion circuit, the container is hermetically sealed to preserve the organ and a gaseous preservation medium is pumped into the interior cavity of the container housing, whereupon the organ is perfused with a gaseous perfusate in the form of the gaseous preservation medium by means of the perfusion circuit. The technical result toward which the group of inventions is directed is that of better maintaining the viability of a donor organ during preservation by means of a donor organ preservation container.

Description

[0001] Method of preserving donor organ and container for preserving donor organ

[0002] The group of inventions relates to methods and devices for preserving donor organs and can be used in the medical industry, in particular in transplantology.

[0003] A method for preserving a donor organ is selected as a prototype, implemented using a container for preserving a donor organ, containing a sealed body designed to accommodate the donor organ in the internal cavity, and a perfusion circuit for pumping liquid perfusate into the vascular network of the organ. The method includes the stages of placing the preserved organ in the internal cavity of the container and connecting it to the perfusion circuit, sealing the container and pumping a liquid preservation medium into its internal cavity, saturating the liquid preservation medium with oxygen, and perfusing the organ with a perfusate represented by a liquid preservation medium pre-saturated with oxygen [WO2020252148A1, publication date: 12 / 17 / 2020]

[0004] The disadvantage of the prototype is the impossibility of ensuring the preservation of donor organs preserved using preservation media and perfusates in the form of liquids or liquids saturated with gases at a sufficiently high level. The preservation of donor organs can be expressed in parameters that determine the functions of the preserved organ, for example, the ability to initiate contractile activity after transplantation or the pressure developed for the heart, bile production for the liver, filtration and reabsorption for the kidneys, etc. Also, the criteria for assessing the preservation of an organ can be common for various types of organs. Such criteria can include the lactate level, the lactate dehydrogenase level, the adenosine triphosphate / adenosine diphosphate ratio, etc.The deterioration of the above-mentioned indicators during the preservation of donor organs using liquids or liquids saturated with gases as preservation media and perfusates is caused by the fact that during the preservation, conditions are created in which an inadequate response to the organ's needs to maintain a sufficient level of energy to ensure its vital activity outside the body occurs, due to which deterioration (decay) of the organ tissues occurs, the intensity of which is determined by the degree of discrepancy between energy expenditure and its generation. At the same time, it is known that the generation of energy in the living tissue of an organ directly depends on its ability to absorb oxygen, which in turn is determined by various factors, including the sufficiency of gas in the environment and the possibility of its transfer from this environment directly to the organ tissue.Normally, such a process is provided by the blood circulation and gas exchange system, the central element of which is hemoglobin, which ensures a constant exchange of gases between the liquid and the tissue of the organ along the gradient of gas concentration. However, in solutions using liquid or liquid saturated with gas as preservation media and perfusates, hemoglobin is absent and the oxygen capacity of preservation media and perfusates (the amount of dissolved oxygen) is determined by their ability to dissolve oxygen. For example, the concentration of oxygen in water is approximately 25 times lower than in blood. At the same time, the cocktail recipe of perfusion solutions, the osmolarity of which is often represented by high-molecular compounds, can further reduce the solubility of oxygen.Thus, liquids or liquids saturated with gases used as preservation media and perfusates have low oxygen capacity and do not provide an adequate response to the organ's need for oxygen, which results in an insufficiently high level of preservation of the donor organ during its preservation, thereby reducing the effectiveness of the donor organ preservation method.

[0005] The technical problem that the group of inventions is aimed at solving is the need to increase the efficiency of the method of preserving a donor organ.

[0006] The technical result, which the group of inventions is aimed at achieving, consists in increasing the safety of a donor organ during its preservation by means of a container for preserving a donor organ.

[0007] The essence of the first invention from the group of inventions is as follows.

[0008] A container for preserving a donor organ, characterized by the fact that it contains:

[0009] — a sealed housing having an internal cavity for accommodating a donor organ and means for accommodating and fixing the donor organ in the internal cavity of the sealed housing, ensuring the possibility of transporting the donor organ in a position anatomical for it, designed with the possibility of pumping a gaseous preservation medium into the internal cavity;

[0010] — a perfusion circuit for pumping gaseous perfusate, which is a preservation gaseous medium, into the vascular network of the donor organ, including a pumping device and a channel for supplying gaseous perfusate to the donor organ;

[0011] — temperature and pressure sensors installed in a sealed housing, where one of the pressure sensors ensures the determination of excess pressure of the gaseous perfusate in the donor organ, and the other ensures the determination of the pressure of the preservation gaseous medium pumped into the internal cavity of the sealed housing.

[0012] The essence of the second invention from the group of inventions is as follows.

[0013] A method for preserving a donor organ, characterized by the fact that it is carried out using a container for preserving the donor organ and includes the following stages:

[0014] — placement of the donor organ in the internal cavity of a sealed housing and connection of the donor organ to the perfusion circuit;

[0015] — sealing the container and pumping a gaseous preservation medium into the internal cavity of the sealed housing at a rate of 0.005 to 0.05 bar / sec until the pressure in the internal cavity is reached ;0Н s (bar), the value of which is determined by the formula:

[0016] Where F02 is the proportion of oxygen in the gas mixture,

[0017] VK — working volume of the container (ml),

[0018] PV02 — organ oxygen requirement during preservation (ml);

[0019] — perfusion of the donor organ with a gaseous perfusate, which is a preservation gaseous medium with an oxygen content of up to 95 vol.%, by means of a perfusion circuit, wherein the perfusion is carried out by supplying the gaseous perfusate to the donor organ in equal parts at intervals of time and the discreteness N (sec / min) of switching on the pumping device of the perfusion circuit is determined by the formula: where Ppump is the peristaltic pump capacity (ml / sec), t is the planned preservation time (min),

[0020] PV02 is the organ's oxygen requirement during preservation (ml).

[0021] The housing, in order to provide the possibility of placing the donor organ in its internal cavity, can be made detachable and consisting, for example, of a container and a lid or a container with a removable base or two hollow mating containers, etc., without being limited by the number of component parts of the housing. These design features of the housing can be provided while simultaneously maintaining its hermeticity. At least one viewing window can be made in the lid and / or walls of the housing, providing the possibility of visual control of the processes of preservation of the donor organ. One or more openings can be made in any part of the housing for supplying a gaseous preservation medium to the internal cavity of the housing and / or removing the medium from it.Shut-off valves may be connected to the said opening or openings, providing the ability to regulate the rate of injection of the gaseous preservation medium into the internal cavity of the housing or the discharge of the gaseous preservation medium from it. The housing may be made heat-insulated, for which purpose it may have a double wall equipped with a heat-insulated layer.

[0022] The perfusion circuit provides the possibility of pumping gaseous perfusate into the vascular network of the organ and for this purpose includes a pumping device, as well as a channel for supplying gaseous perfusate to the organ. The pumping device can be any type of pump that provides a sufficient pressure of the pumped gaseous medium at the outlet from it, for example, a compressor. In the most preferred embodiment, the pumping device can be represented by a peristaltic pump, which additionally eliminates contact of the pumped medium with the working parts of the pump. The intake of gaseous perfusate during the operation of the pumping device is provided from the internal cavity of the housing, while a channel for intake of gaseous perfusate from the internal cavity of the housing can be additionally connected to the inlet of the pumping device.

[0023] The channel for supplying gaseous perfusate to the organ and the channel for collecting gaseous perfusate from the internal cavity of the housing can be made disposable to ensure their sterility and increase the safety of the donor organ during its preservation using a container for preserving the donor organ.

[0024] The pumping device can be installed outside the internal cavity of the housing, and the channel for collecting the gaseous perfusate from the internal cavity of the housing and the channel for supplying the gaseous perfusate to the organ can be introduced into the housing through openings made in it while maintaining its tightness. In this case, in the most preferred embodiment, the pumping device is installed in the internal cavity of the housing. Within the framework of the present group of inventions, the internal cavity of the housing can also be understood as cavities associated with it, made in the walls, bottom and other structural elements of the housing. Preferably, the pumping device can be mounted in the bottom of the housing.

[0025] The gaseous preservation medium pumped into the internal cavity of the body and acting as a gaseous perfusate may be represented by one gas - oxygen or an oxygen-containing gas mixture, for example, air. Also, the oxygen-containing gas mixture may be represented by a mixture of oxygen and one or more adjuvant gases, which may be inert gases such as helium, neon, argon, krypton and xenon, as well as non-inert gases such as nitrogen, hydrogen or carbon dioxide and any gases that are non-toxic to the organ being preserved.

[0026] The oxygen content in the oxygen-containing gas mixture may be up to 95 vol.%, since oxygen is a strong oxidizer and the residual proportion of adjuvant gas may not be able to compensate for the oxidizing properties of oxygen. The gaseous preservation medium may be pumped into the internal cavity of the housing at a rate of 0.005 to 0.05 bar / sec in order to avoid a sharp increase in pressure and prevent the occurrence of negative consequences for the preserved organ as a result. The gaseous preservation medium may be pumped into the internal cavity of the housing until the pressure in the internal cavity is reached, the value of which is determined taking into account such parameters as the proportion of oxygen in the gas mixture, the working volume of the internal cavity of the container and the organ's need for oxygen during preservation.

[0027] Perfusion of the organ being preserved can be carried out by supplying gaseous perfusate to the organ in equal parts at intervals, and the discreteness of switching on the pumping device for supplying perfusate to the organ can be determined taking into account such parameters as the performance of the pumping device, the expected preservation time and the organ's need for oxygen during preservation.

[0028] The placement and fixation of the organ position in the internal cavity of the housing can be ensured by means installed inside it, which can be represented by a tripod, bracket, lodgement or open container containing the said elements, etc. means that ensure the possibility of transporting the organ in an anatomical position for it, in which there is no compression of the elements of its vascular network and its uniform perfusion is ensured. The said means for placing and fixing the position of the organ in the internal cavity of the housing can be made disposable to ensure their sterility and increase the safety of the donor organ during its preservation by means of a container for the preservation of the donor organ.

[0029] To ensure control over organ preservation processes, pressure and temperature sensors may be installed in the housing. At least two pressure sensors may be installed in the housing, one of which ensures the determination of excess pressure of the gaseous perfusate in the donor organ, and the other ensures the determination of the pressure of the gaseous preservation medium pumped into the internal space of the housing.

[0030] Additionally, an aerosol generator can be installed in the inner space of the housing or in the inner space of the container that ensures placement and fixation of the organ position in the inner cavity of the housing, which ensures maintenance of high (at least 80%) humidity in the inner cavity of the housing during the process of organ preservation and prevents drying of the outer surface of the preserved organ. The liquid used to generate an aerosol from it can be any preservative solution, for example, isotonic solution, Krebs-Henseleit, University of Wisconsin solution, Histidine-Tryptophan-Ketoglutarate solution (Custodiol), etc. A humidity sensor can be additionally installed in the housing to control humidity.In this case, to reduce the amount of moisture entering the gaseous perfusate, the intake of which is carried out from the internal cavity of the housing, a moisture separator can be installed at the inlet of the pumping device, or at the inlet end of the channel for collecting gaseous perfusate from the internal cavity of the housing, ensuring the collection of excess moisture from the aerosol and its removal, for example, a funnel or channel, or a branch pipe. Aerosol generation can be carried out simultaneously with the perfusion of the donor organ or automatically according to the set threshold value and sensor readings.

[0031] Upon completion of the method of preserving the donor organ, its depreservation can be performed by releasing the pressure of the gaseous preservation medium in the internal cavity of the housing to atmospheric pressure, depressurizing the housing and perfusing the donor organ with liquid perfusate to replace the gaseous perfusate in its vascular network, for the purpose of subsequent transplantation into the recipient's body.

[0032] A group of inventions can be made from known materials using known means, which indicates its compliance with the patentability criterion of “industrial applicability”.

[0033] The group of inventions is characterized by a previously unknown set of essential features from the state of the art, consisting in the fact that the method of preserving a donor organ is implemented by means of a container for preserving a donor organ, in the internal cavity of which the organ is placed and connected to a perfusion circuit, the container for preserving the organ is sealed and a gaseous preservation medium is pumped into the internal cavity of the housing, and then the organ is perfused with a gaseous perfusate, represented by a gaseous preservation medium, by means of a perfusion circuit, which ensures an increase in the bioavailability of oxygen for the tissues of the preserved organ, since the oxygen is in a gaseous state and is supplied to the vascular network of the preserved organ in the same gaseous state,as a result, the preservation of the donor organ is increased during its preservation using a container for the preservation of the donor organ and the efficiency of the method of preserving the donor organ is increased.

[0034] The group of inventions possesses a set of essential features previously unknown in the state of the art, which indicates its compliance with the patentability criterion of “novelty”.

[0035] The prior art discloses a method for preserving a donor organ in a liquid preservation medium saturated with oxygen, which is also used to perfuse the organ's vascular network. However, the prior art does not disclose a method for preserving a donor organ that uses a gaseous preservation medium and gaseous perfusate, which is why the group of inventions meets the patentability criterion of "inventive step".

[0036] Inventions from a group of inventions are interconnected and form a single inventive concept, which indicates that the group of inventions meets the patentability criterion of “unity of invention”.

[0037] The group of inventions is illustrated by the following figures.

[0038] Fig. 1 - Schematic representation of a container for preserving a donor organ, with the organ to be preserved placed in its internal cavity.

[0039] Fig. 2 - Schematic representation of a container for preserving a donor organ, with an aerosol generator and a funnel for collecting and removing excess moisture from the aerosol installed in its internal cavity, and the organ to be preserved placed in its internal cavity.

[0040] Fig. 3 - Table of results of tests for the presence of heart rhythm.

[0041] Fig. 4 - Graph of the results of tests to determine the heart rate of organs after their preservation.

[0042] Fig. 5 - Graph of the results of tests to determine the volumetric rate of coronary perfusion of organs after their preservation.

[0043] Fig. 6 — Graph of the results of tests to determine the intraleft ventricular pressure of organs after their preservation. Fig. 7 — Table of sections of organs with the largest and smallest proportions of infarction zones.

[0044] Fig. 8 - Graph of the numerical proportions of infarction zones.

[0045] Fig. 9 - Comparative table of the evaluation of the results obtained during all tests.

[0046] To illustrate the possibility of implementation and a more complete understanding of the essence of the group of inventions, a variant of its implementation is presented below, which can be changed or supplemented in any way, while the present group of inventions is in no way limited to the presented variant.

[0047] The container for preserving the donor organ has a hollow body with a cover 10. The cover 10 of the body has a viewing window 12 and is designed to hermetically close the internal cavity of the body. In the lower part of the body there are openings for connecting needle valves for gasification and degassing of the internal space of the body to them. The following are installed in the body: a perfusion circuit, pressure sensors and a temperature sensor, as well as a stand 14 for fixing the position of the donor organ in the internal space of the body.

[0048] The perfusion circuit consists of a peristaltic pump 16, a tube 18 for supplying perfusate to the donor organ, and a tube 20 for collecting perfusate from the internal cavity of the housing.

[0049] One of the pressure sensors can be installed inside the tube 18 for supplying the perfusate to the donor organ or can be installed inside the coupling-adapter installed in the organ artery when performing the method of its preservation, and ensures the determination of the excess pressure of the perfusate in the donor organ. Another of the pressure sensors is installed in the lower part of the housing and ensures the determination of the pressure of the preservation medium pumped into the inner space of the housing. The temperature sensor is installed in such a way as to most accurately measure the temperature of the organ, for example, it can be installed inside the coupling-adapter installed in the organ artery when performing the method of its preservation, or inside the tube 18 for supplying the perfusate to the donor organ or the tube 20 for collecting the perfusate from the inner cavity of the housing, or can be built into any of the parts of the perfusion circuit that has contact with the perfusate.The pressure sensors and temperature sensor, as well as the peristaltic pump 16, are connected to a controller located outside the container body.

[0050] In one embodiment, an ultrasonic aerosol generator 22 and a humidity sensor are additionally installed in the body of the container for preserving the donor organ, which are connected to the controller, while at the input end of the tube 20 for collecting the perfusate from the internal cavity of the body, a funnel 24 is additionally installed for collecting and removing excess moisture from the aerosol created by the generator 22 (Fig. 2). The generator 22 is installed in the lower part of the body, on its bottom, and the humidity sensor is installed at the highest point of the internal space of the body.

[0051] The method of preserving a donor organ, in particular the heart, is implemented as follows.

[0052] The organ is prepared for preservation by washing it from blood residues with a preservative solution, in particular a cardioplegic solution of Histidine-Tryptophan-Kutoglutarate, and installing the coupling-adapter 26 into the organ's aorta. Then the organ is placed in the internal cavity of the body for preserving the donor organ and its position is fixed by means of a stand 14. After this, the organ is connected to the perfusion circuit, in particular to its tube 18 for supplying perfusate to the organ, through the coupling-adapter 26 and the container lid 10 is closed, thereby ensuring the sealing of its internal space.

[0053] After sealing the inner space of the housing, the gasification valve is opened and a gaseous preservation medium, represented by a xenon-oxygen mixture, is pumped into the inner space of the housing. The pressure inside the container is monitored using a pressure sensor. Pumping is carried out at a rate of 0.005-0.05 bar / sec until the pressure Pcons (bar) is reached in the inner space of the housing, determined by the formula: where F02 is the proportion of oxygen in the gas mixture,

[0054] VK — working volume of the container (ml),

[0055] PV02 is the organ's need for oxygen during preservation (ml), determined by the formula: where m is the organ mass (g), t is the planned preservation time (min),

[0056] MVO2 is the organ's need for oxygen under normal conditions and at physiological temperature (ml / min / gram of tissue),

[0057] Ai is a coefficient reflecting the decrease in oxygen consumption by an organ in a relaxed (without contractile activity) state at physiological temperature. For organs that do not have contractile activity, Ai = 1,

[0058] Ag is a coefficient reflecting a decrease in the organ's oxygen consumption during hypothermia,

[0059] Ti is the physiological temperature for the preserved organ (°C),

[0060] Tg is the organ preservation temperature (°C).

[0061] In order to purge the device from the air atmosphere, the 3 / 1 method can also be used: pumping in three volumes of preservative gas, determined in accordance with the above formula, followed by depressurization to atmospheric pressure.

[0062] After reaching the pressure Pcons (or ЗхР КОНc) the injection is stopped and residual air is released from the interior of the housing by opening the degassing valve. The pressure inside the container is also monitored using a pressure sensor. Residual air is released at a rate of 0.005-0.05 bar / sec until the pressure in the interior of the housing reaches Pf ин = Rcons - 1 (bar), if Rf ин > 1 bar, or until the pressure reaches 1 bar, if Рф ин < 1 bar, after which the degassing valve is closed.

[0063] Then the organ perfusion process begins. First, carrying out visual control through the viewing window 12, perfusion of the organ vascular network is performed in a constant mode, i.e. continuously supplying the perfusate to the organ until the release of visible drops of the preservative solution flowing out of the organ vascular network through the organ's venous vessel, in particular through the pulmonary artery and / or the superior-inferior vena cava, ceases, which indicates a hermetic connection of the organ to the perfusion circuit. Then the perfusion mode changes to discrete, in which the perfusate is supplied to the organ in equal parts at intervals, while the discreteness of pump activation N (sec / min) is determined by the formula:

[0064] Where Ppump is the peristaltic pump capacity (ml / sec), t is the planned preservation time (min),

[0065] PV02 is the organ's oxygen requirement during preservation (ml).

[0066] In this case, the discreteness of switching on the pump N should not be so rare that the perfusate pressure equalizes with the pressure of the gaseous preservation medium in the internal space of the housing. Thus, the discreteness of switching on the pump should be adequate to the throttle (relieving excess pressure) feature of the organ and maintain the value of excess perfusate pressure at a level from 0.1 to 80 mm Hg.

[0067] The perfusate is collected in both continuous and discrete perfusion modes by means of a peristaltic pump 16 through a tube 20 from the internal cavity of the housing filled with a gaseous preservation medium. The pressure of the perfusate in the vascular network of the organ being preserved is monitored by means of a pressure sensor installed in the coupling-adapter 26.

[0068] When establishing a discrete perfusion mode and filling the bottom of the housing with a preservative solution, including that flowing out of the organ as a result of its replacement with a gaseous perfusate, the aerosol generator 22 is started to ensure humidity in the internal cavity of the housing at a level of at least 85%, while the generator 22 is turned on and the aerosol is generated by it simultaneously with the peristaltic pump 16, which performs perfusion of the organ in a discrete mode, and the synchronization of their operation is ensured by the controller.

[0069] During the operation of generator 22, it generates an aerosol from a preservative solution. In this case, the collection of excess moisture from the aerosol by funnel 24 and its subsequent removal, as well as the outflow of excess solution from the organ's vascular network (entering it together with the gaseous perfusate), ensures that the level of this solution at the bottom of the housing is maintained constant and sufficient for wetting the working element of generator 22.

[0070] After establishing the perfusion and aerosol generation modes, the body of the container for preserving the donor organ is placed in a refrigeration chamber, cooled together with its contents to a temperature of Ti = 1-4°C, and the established temperature is maintained, as well as the organ perfusion and aerosol generation modes, throughout the entire time of organ preservation.

[0071] The organ is de-preserved as follows.

[0072] Upon completion of the organ preservation period, the body of the donor organ preservation container is removed from the refrigeration chamber and the degassing valve is opened, releasing the pressure in the inner space of the body to atmospheric pressure at a rate of 0.005-0.05 bar / sec, while the pressure is monitored using a pressure sensor. Upon reaching a pressure in the inner space of the body corresponding to atmospheric pressure, the cover 10 of the body is opened and liquid perfusion of the organ is performed to replace the gaseous perfusate in its vascular network with a liquid one, represented by a preserving solution. For this purpose, the organ is removed from the inner cavity of the body without disconnecting it from the perfusion circuit, and the inlet end of the tube 20 for collecting the perfusate is connected to a container with a preserving solution and liquid perfusion of the organ is performed in a constant mode until the perfusate pressure in the organ vascular network is reached, amounting to from 80 to 250 mm Hg., after which the adapter coupling 26 is disconnected from the aorta and the organ is prepared for further transplantation.

[0073] For organs preserved in the manner described above, the efficiency of their preservation was determined using various preservation media, which are also the perfusate by means of which the perfusion of the preserved organ is carried out. The following preservation media were presented as the studied ones:

[0074] - xenon-oxygen mixture containing 5% oxygen and 95% xenon (Gas A);

[0075] - xenon-oxygen mixture containing 95% oxygen and 5% xenon (Gas B);

[0076] - xenon-oxygen mixture containing 50% oxygen and 50% xenon (Gas C);

[0077] - air; - preservative cardioplegic solution of Histidine-Tryptophan-Ketoglutarate (KR), trade name "Custodiol".

[0078] When using the cardioplegic solution "Custodiol" as a preservation medium, it was pumped directly into the vascular network of the organ, through its arterial part, thus washing the vascular network of the organ from residual blood for 3-5 minutes with simultaneous stopping of the rhythm (heartbeat), and then the perfusion of the organ was stopped and it was immediately transferred to the liquid phase of the ice-cold (part of the solution is represented by ice chips) solution "Custodiol", for the entire preservation period.

[0079] In each of the preservation environments, four to ten organs were preserved separately, in particular:

[0080] The preserved organs were rat hearts. The preservation period was 6 hours. At the end of the preservation period, tests were conducted for each of the preserved organs to determine the possibility of starting the contractile activity of the organ, namely the presence of a heart rhythm. The test results are given in the table shown in Fig. 3. From this table it is evident that the percentage of organs that successfully passed the tests for the presence of a heart rhythm was 100% for gases A, B and C, 75% for air and 40% for the KR "Custodiol".

[0081] For organs that successfully passed the cardiac rhythm tests, additional tests were performed using the Langendorff technique, in which the organ was perfused antegradely with Krebs-Henseleit solution for 60 minutes in constant pressure mode and the following parameters were determined:

[0082] - heart rate (HR, bpm);

[0083] - coronary perfusion volume rate (ml / min);

[0084] - intraleft ventricular pressure (mmHg);

[0085] - the proportion of infarction zones in the organ (%).

[0086] The results of determining the heart rate after preservation are shown in the graph shown in Fig. 4. When comparing the results of various preservation media, it was found that the heart rate was significantly higher (p < 0.05) for all gases A, B and C compared to the CR "Custodiol", as well as for the pairs air - Gas B (p = 0.015) and Gas C (p = 0.01). At the same time, there were no differences in the pairs air - CR "Custodiol" and air - Gas A (p > 0.05). The latter may indicate a depriving effect of Gas A on the cardiac conduction system, which may be due to the relatively high concentration of xenon in this mixture. The ability to maintain a correct (sinus) heart rhythm with a sufficient frequency is an important indicator of organ preservation, ensuring adequate organ function after transplantation. Deterioration of this indicator indicates a violation of the organ automatism as a result of its preservation.

[0087] The results of determining the volumetric coronary perfusion rate after preservation are shown in the graph presented in Fig. 5. When comparing the results of determining the volumetric coronary perfusion rate for different preservation media, it was found that this indicator for all gases A, B and C did not differ when compared with the indicator for the KR "Custodiol", but significant differences were observed in the pair KR "Custodiol" - air (p = 0.029), while the indicator for air was reduced in comparison with the indicator for the KR "Custodiol". Such results may indicate an unfavorable effect of air on the vascular network of the organ, resulting in an increase in its resistance.

[0088] The results of determining the intraleft ventricular pressure after preservation are shown in the graph shown in Fig. 6. When comparing the results of determining the intraleft ventricular pressure for different preservation media, a significant decrease in this indicator was found for the CR "Custodiol" and air compared to the indicators for gases A, B and C. At the same time, for pairwise comparisons of gas mixtures with the CR "Custodiol", the p-value was less than 0.01 in all cases, while for pairwise comparisons with air, a lower, but also reliable, significance of differences was revealed (the p-value in all cases was less than 0.05). It is noteworthy that despite the higher average (and median) value of the indicator for air, when comparing the air - CR "Custodiol" pair, no significant differences were observed (p> 0.05).High values ​​of the indicator of pressure developed by the heart after its preservation indicate better preservation of the organ in comparison with the indicated competitive techniques, including the KR "Custodiol". On the other hand, significant differences in the indicators of gases A, B and C and air indicate that increased preservation when using gases A, B and C is not only an attribute of the technology of gas perfusion of the organ, but is also due to the composition of the gases mentioned.

[0089] Sections of organs with the largest and smallest proportions of infarction zones among all the organs studied for all the preservation media studied are given in the table presented in Fig. 7. A graph reflecting the numerical proportions of infarction zones determined using the ImageJ utility is shown in Fig. 8. From this graph it is evident that the smallest proportion of infarction zones among all organs were possessed by organs preserved using gases A, B and C as preservation media, with the best results being obtained with Gas B.

[0090] Based on the results of all the tests, a comparative table was compiled, shown in Fig. 9. The specified table reflects the assessment of the obtained results of the presence of cardiac rhythm, as well as the obtained indicators of heart rate, volumetric coronary perfusion rate, intraleft ventricular pressure and the proportion of infarction zones. The indicators corresponding to satisfactory are marked in the table as "+", and those not corresponding to satisfactory are marked as "-". The table also reflects the total number of indicators corresponding to satisfactory, for each of the preservation media used. Based on the results of the comparative table, it is evident that Gas B had the largest number of satisfactory indicators (4 out of 5), which characterizes it as the most effective for use as a preservation medium.In this case, all gases A, B and C were superior in efficiency to air and KR "Kustodiol", however, air was superior to KR "Kustodiol" in the most important indicator, the presence of cardiac rhythm, that is, the ability to initiate contractile activity, which indicates, in general, a higher efficiency of using preservation media in a gaseous aggregate state for the preservation of organs, in comparison with media that are liquid.

[0091] This ensures the achievement of a technical result consisting in increasing the safety of the donor organ during its preservation using a container for preserving the donor organ, thereby increasing the efficiency of the method of preserving the donor organ.

Claims

Formula 1. A container for preserving a donor organ, characterized by the fact that it contains: — a sealed housing having an internal cavity for accommodating a donor organ and means for accommodating and fixing the donor organ in the internal cavity of the sealed housing, ensuring the possibility of transporting the donor organ in a position anatomical for it, designed with the possibility of pumping a gaseous preservation medium into the internal cavity; — a perfusion circuit for pumping gaseous perfusate, which is a preservation gaseous medium, into the vascular network of the donor organ, including a pumping device and a channel for supplying gaseous perfusate to the donor organ; — temperature and pressure sensors installed in a sealed housing, where one of the pressure sensors ensures the determination of excess pressure of the gaseous perfusate in the donor organ, and the other ensures the determination of the pressure of the preservation gaseous medium pumped into the internal cavity of the sealed housing.

2. The container according to item 1, characterized in that the pumping device is represented by a peristaltic pump.

3. A container according to item 1, characterized in that a channel for collecting gaseous perfusate from the internal cavity of a sealed housing filled with a gaseous preservation medium is connected to the input of the pumping device.

4. The container according to item 3, characterized in that the channel for supplying gaseous perfusate to the donor organ and the channel for collecting gaseous perfusate from the internal cavity of the sealed housing are made disposable.

5. The container according to item 1, characterized in that the pumping device is installed in the internal cavity of the sealed housing.

6. The container according to item 5, characterized in that the pumping device is mounted in the bottom of the sealed housing.

7. A container according to item 1, characterized in that a viewing window is provided in the sealed body.

8. A container according to item 1, characterized in that the means for placing and fixing the organ in the internal cavity of the sealed housing are disposable.

9. The container according to item 1, characterized in that an aerosol generator is installed in the internal space of the sealed container body.

10. The container according to item 1, characterized in that a humidity sensor is installed in the sealed body of the container.

11. A container according to paragraphs 3 and 9, characterized in that a moisture separator is installed at the inlet of the pumping device or at the inlet end of the channel for collecting gaseous perfusate from the internal cavity of the sealed housing, ensuring the collection of excess moisture from the aerosol and its removal.

12. A method for preserving a donor organ, characterized in that it is carried out using a container for preserving a donor organ according to any of paragraphs 1-11, and includes the following steps: — placement of the donor organ in the internal cavity of a sealed housing and connection of the donor organ to the perfusion circuit; — sealing the container and pumping a gaseous preservation medium into the internal cavity of the sealed body at a rate of 0.005 to 0.05 bar / sec until the internal cavity reaches a pressure of G КО ns (bar), the value of which is determined by the formula: Where F02 is the proportion of oxygen in the gas mixture, VK — working volume of the container (ml), PV02 — organ oxygen requirement during preservation (ml); — perfusion of the donor organ with a gaseous perfusate, which is a preservation gaseous medium with an oxygen content of up to 95 vol.%, by means of a perfusion circuit, wherein the perfusion is carried out by supplying the gaseous perfusate to the donor organ in equal parts at intervals of time and the discreteness N (sec / min) of switching on the pumping device of the perfusion circuit is determined by the formula: where Ppump is the peristaltic pump capacity (ml / sec), t is the planned preservation time (min), PV02 is the organ's oxygen requirement during preservation (ml).

13. The method according to item 1, characterized in that simultaneously with the implementation of perfusion of the donor organ, aerosol generation is carried out until the relative humidity in the internal cavity of the sealed housing is provided at a level of at least 80%.

14. The method according to paragraph 1, characterized in that a preservative solution is used to generate the aerosol.

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