RU2226111C2 - Method and device for applying artificial blood circulation - Google Patents

Abstract

FIELD: medicine. SUBSTANCE: method involves supplying blood or artificial blood substitute agent into arterial blood vessel in pulsating mode at helical trajectory and removing the mentioned blood or artificial blood substitute agent from venous blood vessels. The device has blood or artificial blood substitute agent supply means operating in pulsating mode, means for saturating blood or artificial blood substitute agent with oxygen, reservoir, means for connecting the device to venous blood vessels, and means for connecting the device to arterial blood vessel manufactured in a way that blood or artificial blood substitute agent come to the mentioned arterial blood vessel in helical flow mode. EFFECT: enhanced effectiveness in reproducing natural physiological blood circulation motion. 9 cl, 2 dwg

Description

The invention relates to medicine and can be used mainly in cardiac surgery to provide cardiopulmonary bypass during heart surgery.

Various methods of cardiopulmonary bypass and apparatus for their implementation are known and widely used. Said methods include supplying blood, a blood substitute, or a mixture thereof, to an arterial vessel under pressure, ensuring the progressive passage of said blood, blood substitute, or a mixture thereof, through the circulatory system. By the nature of the perfusion of blood into the arterial vessel, the methods and, accordingly, the apparatuses are divided into two types: with continuous perfusion and with pulsating perfusion [Osipov V.P. The basics of cardiopulmonary bypass - M .: Medicine, 1979], the latter being currently used to a lesser extent, since peripheral arterial resistance increases with pulsating perfusion.

When using known methods and devices, a large number of pathophysiological disorders occur, causing various complications, so the recovery period after operations is increased. [Chepky L.P., Sidorenko A.A. and others. Dangers and complications of operations with cardiopulmonary bypass. - Kiev: Health, 1975]

Such complications, for example, include:

- violation of regional blood circulation (heart, brain, lungs, kidneys, liver);

- mixed-type metabolic acidosis (tissue and cell);

- blood stasis in the microvascular bloodstream;

- postperfusion bleeding due to a violation of the blood coagulation system;

- violation of gas exchange and metabolism;

- blood stasis in the venous bed;

- hemodilution:

- hyperhydration, which increases the volume of extracellular fluid and increases interstitial pressure, leading to edema of mixed-type tissues (cellular and tissue);

- Violation of osmotic and colloidal homeostasis, leading to a deterioration in blood rheology due to wrinkling of red blood cells and increased peripheral resistance of blood vessels;

- postperfusion bleeding due to dilution of blood coagulation factors;

- development in the postperfusion period of acute cardiovascular failure.

The above complications arise due to the fact that the known methods and apparatus of cardiopulmonary bypass do not take into account the specifics of the blood vessels, they do not reproduce the natural nature of the movement of blood in the bloodstream. Recent studies of blood circulation biomechanics have experimentally shown that in the bloodstream, as well as in the entire cardiovascular system, blood movement is not translational, as previously thought, but rotational-translational in nature, and the direction of rotation of the blood flow is large and pulmonary circulation, the opposite [Bagaev S.N., Zakharov V.N., Orlov V.A. Physical mechanisms of transport systems of a living organism (Preprint) - Novosibirsk: SB RAS, 1999]

The prerequisites for the formation of rotational-translational movement of blood are that the muscle elements of the myocardium of the ventricles of the heart and blood vessels have a spiral packing, their cavities are funnel-shaped chambers with asymmetries of entry and exit, and the branching of the main arterial and venous channels is tangential. The establishment of these facts contributed to a new understanding of the biomechanics of blood circulation and, in particular, led to the idea of a "distributed heart". The blood flow entering the main arterial bed during systole of the ventricles of the heart initially has a rotational-translational character of movement. Since, just as in the myocardium, smooth myocytes of arterial vessels are spirally packed, stretching of the walls of blood vessels receiving a systolic blood flow leads to tension of smooth muscle elements and a spiral wave of their excitation. Further, the addition of the forces of elastic deformation of the elastic skeleton and the active contraction of smooth myocytes in the walls of the arteries creates a twisting wave in them, ensuring the preservation of the swirling flow, supporting not only the translational component of the blood movement, but, importantly, the rotational one. Over the period of the cardiac cycle, the reduction and relaxation of the active elements of the walls of the vessels occurs alternately, and this process extends from the heart to the periphery of the main arterial vessels. The activity of each section of the main arterial vessel is similar to the activity of the ventricle of the heart, since there are phases of spiral contraction and relaxation of the muscle layer of blood vessels, and in general, the activity of the heart and blood vessels is synchronized. Using X-ray contrast studies, it was found that in the initial sections of the arterial bed of the circulatory system, translational energy is approximately two times less than rotational energy, which creates additional blood traction. This effect also manifests itself in a universal manner in numerous funnel-shaped chambers of the circulatory system. The functional role of the rotational component of the blood movement is to overcome the distributed resistance of the vessels, the value of which is determined by viscous friction. Summing up over each small section of the circulatory system, the named resistance integrally becomes large. An indicator of this resistance is the measured arterial diastolic pressure.

From the standpoint of the new concept of circulatory biomechanics, the causes and consequences of pathophysiological processes and complications arising from cardiopulmonary bypass movement in vessels, when the active role of vessels in providing blood flow is excluded, and to compensate for friction losses during extracorporeal circulation by the perfusion pump, excess pressure 2-3 times higher than the physiological level.

The closest analogue of the proposed method of cardiopulmonary bypass is a method of pumping blood, including supplying the circulatory system with blood (and / or a blood substitute), by pulsating supply to the arterial vessel, ensuring its progressive movement through the circulatory system, and removing said blood and / or blood substitute from the circulatory system through a venous vessel [A.S. USSR No. 1320932 IPC A 61 M 1/10]. This method for the greatest number of similar to the proposed features adopted for the prototype of the invention. The disadvantages of the prototype is that it does not reproduce the natural nature of the movement of blood in the circulatory system, which excludes the active work of blood vessels and ultimately leads to various pathophysiological processes in the body, disorders and complications listed above.

The invention solves the problem of creating a method and apparatus of cardiopulmonary bypass, reproducing the natural, physiological movement of blood in the circulatory system, and not causing various pathophysiological processes and disorders in the body, operational and postoperative complications.

The problem is solved in that a method of cardiopulmonary bypass is provided, which includes supplying the circulatory system with blood and / or a blood substitute by means of a pulsating supply of said blood and / or a blood substitute into an arterial vessel, removing said blood and / or blood substitute from the circulatory system through a venous vessel, in which blood and / or blood substitute is carried out in such a way that they enter the arterial vessel along a helical path.

Since in the physiological conditions of a living organism there is an active return of blood from the venous trunks of a large circle of blood circulation by the activity of the right ventricle of the heart, which creates a suction effect for blood during the period of ventricular diastole (active diastole of the heart), in order to avoid overhydration (tissue supersaturation with liquid) and create conditions as close as possible to natural, it is most effective to forcefully remove the blood and / or blood substitute through the venous vessel, so that the volume m of blood and / or blood substitute supplied to the circulatory system corresponded to the volume of said blood and / or blood substitute removed from the said circulatory system.

During cardiopulmonary bypass, it is possible to constantly supply fresh blood and / or blood substitute to the circulatory system, however, it is most economical to circulate the same volume of blood and / or blood substitute, for which, after exiting the venous vessel, it is oxygenated - saturated with oxygen, and again fed to circulatory system.

The optimal physiological ratio of the rotational and translational speeds of the helical blood flow is √2: 1, respectively, and systolic to diastolic blood pressure is 3: 2. Given that under physiological conditions of blood flow in arterial vessels of a large circle of blood circulation, there is a helical flow with a left direction of blood rotation, it is necessary to supply blood and / or a blood substitute to an arterial vessel of a large blood circulation with a left direction of rotation.

To implement this method, a cardiopulmonary bypass device is proposed. Its closest analogue is an apparatus including a means of supplying blood and / or a blood substitute to the circulatory system in a pulsating mode, a means of enriching blood and / or a blood substitute with oxygen, a means of connecting the apparatus to an arterial vessel, and a means of connecting the apparatus to a venous vessel [A.S. USSR No. 1320932 MKP A61M 1/10]. This device for the greatest number of similarities with the proposed device features adopted for its prototype.

The proposed device contains a means of supplying blood and / or a blood substitute to the circulatory system in a pulsating mode, a means of enriching blood and / or a blood substitute with oxygen, a means of connecting the apparatus with an arterial vessel and a means of connecting the apparatus with venous vessels, and the means of connecting the apparatus with an arterial vessel that the blood and / or blood substitute enters the named arterial vessel in the form of a helical flow.

The apparatus may also be equipped with a means for forcibly removing blood and / or a blood substitute from a venous vessel, which allows the removal of said blood and / or blood substitute from the circulatory system in such a way that the rate of blood removal from the circulatory system corresponds to the rate of blood supply to the circulatory system.

The means for connecting the apparatus to the arterial vessel can be made in the form of a cannula, the end of which, introduced into the arterial vessel, has the shape of a hollow spiral, the outer diameter of the spiral being equal to the inner diameter of the arterial vessel.

A pulsating pump can be used as a means of supplying blood and / or a blood substitute to the circulatory system in a pulsating mode.

As a means of enriching blood and / or blood substitute oxygen can be used oxygenator.

As a means of forcibly removing blood and / or a blood substitute from venous vessels, a pump can be used.

The physiological functioning of the cardiopulmonary bypass device is also achieved by the fact that the performance of the pump for the forced removal of blood and / or blood substitute from a venous vessel is respectively equal to the performance of a pulsating perfusion pump that pumps blood and / or blood substitute into an arterial vessel. Since the minute volume of blood circulation is individual for each patient, the pumps have adjustable performance, which makes it possible to configure them individually for each patient.

The method of cardiopulmonary by using the apparatus as follows.

Figure 1 shows the apparatus of cardiopulmonary bypass. It contains: a perfusion pulsating pump 1, oxygenator 2, arterial cannula 3, venous cannulas 4, a reservoir for collecting blood 5, coronary drainage 6, ventricular drainage 7, an air filter 8 and an additional pump 9. Venous cannulas 4 are introduced into the upper and lower hollow veins, and arterial cannula 3 into the arterial vessel. An additional pump 9 is connected to an oxygen generator 2, which is also connected to an air filter 8. The air filter 8 has two tubes, one of which is connected to a blood collection tank 5, and the other to a perfusion pump 1. A coronary tube is introduced into the blood collection tank 5 drainage 6 and ventricular drainage 7. The perfusion pump 1 is connected to the arterial cannula.

When connecting the device to the patient, venous cannulas 4 are inserted into the superior and inferior vena cava, and arterial cannula 3 is inserted into the aorta, as shown in FIG. An additional pump 9 actively carries out the return of blood from the venous section of the pulmonary circulation and simultaneously pumps blood from the blood collection tank 5, into which blood is collected by coronary drainage 6 and ventricular drainage 7. The additional pump 9 directs blood to the oxygen generator 2, where blood is saturated with oxygen .

Oxygenated blood enters the perfusion pump 1 through an air filter 8, which prevents gas embolism. Gas bubbles in the event of their occurrence are diverted by a connecting tube into the blood collection tank 5, where there is an air level and blood. The perfusion pump 1 creates a pulsating flow of blood into the arterial vessel through the arterial cannula 3, the end part of which is introduced into the named vessel, has the form of a spiral, and the outer diameter of the spiral part of the cannula is equal to the inner diameter of the named vessel, which ensures a stable position of the cannula in it and blood supply into it along a helical path. A certain step of the helical trajectory provides a strict ratio of the rotational speed of the helical blood flow and its translational speed, equal to √2: 1. This ratio of the speeds of the helical blood flow provides an optimal level of the ratio of systolic and diastolic blood pressure, which in the initial section of the aorta is normally 3/2. In addition, the rotational component of the movement of the helical blood flow provides a distributed diastolic gradient, aimed at overcoming the distributed vascular resistance and achieving the main goal - the efficiency of microcirculation.

The use of the device excludes hemodilution, does not require the creation of excess pressure with a perfusion pump, and also allows the use of a minimum of donor blood and pharmacological agents.

Thus, the proposed method of cardiopulmonary bypass and the apparatus for its implementation provide physiological blood flow in the circulatory system, which in turn eliminates numerous disorders, surgical and postoperative complications in the operated patients.

Claims (9)

1. The method of cardiopulmonary bypass, including supplying the circulatory system with blood and / or blood substitute by pulsating supply of the named blood and / or blood substitute to the arterial vessel and removing the named blood and / or blood substitute from the circulatory system through venous vessels, characterized in that the blood and / or or blood substitute is carried out in such a way that they enter the arterial vessel along a helical path. 2. The method according to claim 1, characterized in that the removal of blood and / or blood substitute through the venous vessels is carried out forcefully and so that the volume of blood and / or blood substitute supplied to the circulatory system corresponds to the volume of blood removed from the said circulatory system. 3. The method according to claim 1 or 2, characterized in that the blood and / or blood substitute after they are removed from the circulatory system is subjected to oxygenation and again served in the said circulatory system. 4. The apparatus of cardiopulmonary bypass, including a means of supplying blood and / or a blood substitute to the circulatory system in a pulsating mode, a means of enriching blood and / or a blood substitute with oxygen, a means of connecting the apparatus to an arterial vessel, and a means of connecting the apparatus to venous vessels, characterized in that the means of connection apparatus with an arterial vessel is made in such a way that blood and / or blood substitute enter the named vessel in the form of a helical flow. 5. The apparatus according to claim 4, characterized in that it contains a means of forced removal of blood and / or blood substitute from venous vessels, which ensures the removal of the named blood and / or blood substitute from the circulatory system in such a way that the average rate of blood removal from the circulatory system corresponds the rate of blood supply and / or blood substitute to the circulatory system. 6. The apparatus according to claim 4, characterized in that the means for connecting the apparatus to the arterial vessel is made in the form of a cannula, the end part of which is inserted into the vessel, made in the form of a hollow spiral, the outer diameter of the spiral being equal to the inner diameter of the arterial vessel. 7. The apparatus according to claim 4, characterized in that the means for supplying blood and / or blood substitute to the circulatory system in a pulsating mode is made in the form of a pulsating pump. 8. The apparatus according to claim 4, characterized in that the means of enriching the blood and / or blood substitute with oxygen is made in the form of an oxygenator. 9. The apparatus according to claim 4, characterized in that the means of forced removal of blood and / or blood substitute from a venous vessel is made in the form of a pump.

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