The invention generally relates to systems and methods for ex-situ heart perfusion, preservation and therapy. More particularly, in various enibodiments, the invention applies specifically to Cardiac surgery, Transplantology and Extracorporeal perfusion medicine.
The Organ Care System (OCS™; Transmedics®) is the only normothermic ex-vivo perfusion system available clinically and which is the most similar to the claimed invention in technical essence and has been chosen as a prototype. It is a portable system allowing normothennic oxygenated blood to perfuse the donor heart, which continues to be beating state outside the body (U.S. Pat. Nos. 9,301,519B2, 7,651,835B2).
This system includes a compact wireless monitor, a special perfusion module, and the necessary solutions. The aorta and pulmonary artery of the donor heart are cannulated and the heart is connected to the OCS device. In the OCS, oxygenated blood is pumped into the aorta, perfusing the coronary arteries. The coronary sinus blood flow then passes through the tricuspid valve (as both the superior and inferior vena cavae are surgically closed) and is ejected by the right ventricle into a pulmonary artery catheter and returns to the blood reservoir. For the primary volume of the perfusion module the donor blood (1200-1500 mL) and special solution is used. The standard method to arrest the donor heart is giving hypothermic (4° C.) crystalloid cardioplegic solution such as Custodiol 1000 mL After connecting the heart to the OCS perfusion system and restoration of normal heart function, the piston-type pump maintains only non-linear perfiisate flow to adjust the mean aortic pressure between 60 mmHg and 90 mmHg and coronary flow between 650 mL/min and 850 mL/min The coronary circulation is supported by isotonic solution with electrolytes, amino acids, insulin and adenosine at a rate of 0-30 mL/hour, epinephrine 2-10 mcg/min injected into perfusate. A special gas mixture with a flow of 250-300 mL/min is used to maintain oxygenation of the heart. Gas and acid-base state of the perfiisate is routinely analyzed during system operation to assess the adequacy of the heart blood supply. It should be noted that if the venous lactate level exceeds 5 mmol/mL the organ is deemed unsuitable for further use. Samples are analyzed by means of a portable analyzer.
Several fundamental disadvantages of the above-described prototype system limit its use for prolonged perfusion during conditioning and treatment of the donor heart, namely:
Nowadays, there are other designs of donor heart perfusion/conditioning devices:
There are many unresolved issues in the abovementioned devices:
Thereby, the purpose of the present invention is to develop a compliant universal portable system for donor heart normothermic preservation and long-term transportation, which would eliminate the disadvantages of similar devices mentioned above.
The aims of the invention are the following: providing of effective perfusion of heart in both beating and non-beating conditions, effective hemocorrection therapy of perfusion solution, flow parameters control by switching linear to non-linear flow and vice versa, and mobility of the system.
To solve the task the system is equipped with a special closed integrated box reservoir to place a donor heart in and universal (applicable in routine perfilsion practice) ports for connection of circuit lines.
The specified task is solved, and technical results are achieved by running the system circulation with centrifugal pump, of which the impeller is suspended in a magnetic field thereby not causing damage to the blood formed elements. The capacity of this pump varies from a few milliliters to several liters. Moreover, the functioning of the impeller provides both linear and non-linear flow with different frequency.
The system simultaneously integrates with several circuits for extracorporeal hemocorrection and hemodiafiltration, which also solves the technical task.
The task is also solved by using a normothermic cardioplegic solution based on donor's blood and crystalloid solution in a 5:1 ratio (potassium chloride 4% (30 mL), magnesium sulfate 25% (1.0 mL), lidocaine 2% (2 mL), sodium hydrocarbonate (13 mL) mannitol 15% (6.5 mL)
The technical task of keeping the required temperature of the donor organ is solved by heat exchange at the oxygenator level as the most effective way.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.
In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiment will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
The system of the invention for normothermic ex-situ heart perfusion is schematicafly presented in
It should be noted, although not specifically shown that arrangement/system of connecting pipes may include integrated ports for modules of extracorporeal hemocorrection, hemodiafiltration and laboratory control of perfusate composition.
Thus, according to the invention, in order to place the donor heart in the system, a special closed box with reservoir 1 is used having universal ports for connecting the pipes 4, which are used in routine perfusion practice. The circulation in the system is carried out by one centrifugal pump 3, whose impeller (blade wheel), when functioning, is suspended in a magnetic field and does not cause damage to the formed elements of the blood. The proper temperature of the organ is maintained by implementing heat exchange at the level of the oxygenator 2, as the most effective place.
The performance of the centrifugal pump varies from several milliliters to several liters. Moreover, the functioning of the impeller provides for the provision of laminar flow with different frequencies
It should also be noted that at the same time the system is integrated with several circuits for carrying out extracorporeal hemocorrection and hemodiafiltration.
The method of the ex-situ normothermic heart perfusion functions as follows. The aorta of the heart is cannulated, and connected to the system shown in
The capacity of the device is monitored and controlled by an integrated electronic system. A special gas blender controls oxygen and gas components supply, The system lines provide integrated ports for hemocorrection and hemodiafiltration modules, and for laboratory sampling the perfusate.
Number | Date | Country | Kind |
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2022/0415.1 | Jun 2022 | KZ | national |