JP5347601B2 - Blood processing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To exchange gas stably with a compact device by high gas exchange capability at an early stage of use and avoidance of blood plasma leakage during many hours' continuous use. <P>SOLUTION: A blood treatment device includes: a dense module 1 arranged with many dense hollow fiber membranes 1a; a porous module 2 arranged with many porous hollow fiber membranes 2a; a housing 3 having first and second gas exchange parts 4, 5 for housing the dense module and the porous module in a layered state; a sealing member 6 for exposing openings of both hollow fiber membranes to seal both end parts and forming in the middle area a blood flow path 8 which is extended in the direction crossing the axis direction of both hollow fiber membranes and passes blood through the first and second gas exchange parts; a blood flow-in port 9 and a blood flow-out port 10 which face openings on both ends of the blood flow path and each is provided for a housing; and air supply ports 11a, 11b and air exhaust ports 12a, 12b facing openings on both ends of both hollow fiber membranes and provided for the housing, respectively. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a blood processing apparatus used for extracorporeal circulation in cardiovascular surgery to supply oxygen to blood and remove carbon dioxide.

  In the past, percutaneous cardiopulmonary support (PCPS) was often used for severe heart failure, cardiomyopathy, difficulty in cardiopulmonary detachment, etc. Recently, in the critical care area, even in cases of cardiopulmonary arrest etc. as an emergency response Use is increasing. In such an auxiliary circulation, a hollow fiber membrane that generally incorporates a hollow fiber membrane in an extracorporeal circuit device in order to guide the patient's blood outside the body, supply oxygen thereto, and remove carbon dioxide. A type oxygenator is placed.

  FIG. 3 is a front view showing a configuration example of a hollow fiber membrane oxygenator described in Patent Document 1 in partial cross section. In the hollow fiber membrane oxygenator housing 20, annular male threaded attachment covers 22 and 23 are provided at both ends of the cylindrical main body 21. In the housing 20, a large number (for example, 10,000 to 70,000) of hollow fiber membranes 25 forming the hollow fiber bundle 24 are spaced apart from each other in parallel along the longitudinal direction of the housing 20. Both ends of the hollow fiber membrane 25 are liquid-tightly supported by the partition walls 26 and 27 in the attachment covers 22 and 23 in a state where the respective openings are not closed.

  The partition walls 26 and 27 together with the outer peripheral surface of the hollow fiber membrane 25 and the inner surface of the housing 20 constitute a gas chamber 28 for oxygen-containing gas, which is closed and formed inside the hollow fiber membrane 25. The blood side flow path and the gas chamber 28 are isolated. One mounting cover 22 is provided with an inlet 29 for supplying an oxygen-containing gas, and the other mounting cover 23 is provided with a lead-out port 30 for discharging the oxygen-containing gas. Usually, the partition walls 26 and 27 are formed of a high-potential polymer potting material such as polyurethane, silicone, epoxy resin, or the like. The outer surfaces of the partition walls 26 and 27 are respectively covered with flow path forming members 31 and 32 having annular convex portions. As a result, a blood inflow chamber 33 and an outflow chamber 34 are formed. Blood inlets 35 and outlets 36 are formed at the tops of the flow path forming members 31 and 32, respectively.

  As described above, this hollow fiber membrane oxygenator circulates blood on the inner surface side of the hollow fiber membrane 25 and supplies oxygen-containing gas to the outer surface side of the hollow fiber membrane 25 to perform gas exchange. Perfusion type.

  As such a hollow fiber membrane for artificial lungs, a hollow fiber membrane made of a porous hollow fiber membrane excellent in gas exchange capacity or a membrane material having a dense membrane or a homogeneous membrane suitable for long-term assistance (In the following description, they are collectively referred to as a dense hollow fiber membrane).

  As the porous hollow fiber membrane, for example, a membrane using a porous membrane such as a microporous polypropylene membrane is known. In the porous hollow fiber membrane, since the fine pores of the membrane are significantly larger than the gas molecules to be permeated, the gas passes through the pores as a volume flow and exhibits excellent gas exchange performance. However, the porous hollow fiber membrane has a high water vapor permeability, and when the blood is circulated extracorporeally for a long time, the pores are hydrophilized by the components in the blood and the plasma leaks. Therefore, although the gas exchange performance is excellent in a short time use, there is a drawback that the plasma leakage increases with the passage of blood perfusion time and becomes unusable. Intraoperative plasma leakage causes serious consequences for the patient. However, trying to replace the artificial lung to avoid this involves a great deal of effort and great risk.

  On the other hand, as a dense hollow fiber membrane, for example, a silicone membrane is known. In the hollow fiber membrane using this membrane material, the gas is moved by dissolving and diffusing permeating gas molecules in the membrane. In the case of a dense hollow fiber membrane, although plasma leakage is sufficiently suppressed in practice, for example, a silicone membrane cannot have a strength of 100 μm or less because of its strength. Inferior in gas exchange performance. Therefore, in order to obtain a sufficient gas exchange capacity, a large membrane area, that is, a large artificial lung is required. As a result, since a large amount of priming blood is required, the biological load is large and the application range is limited.

  Patent Document 2 describes an improvement of a membrane material to compensate for the above-described drawbacks of a porous hollow fiber membrane and a dense hollow fiber membrane. That is, the hollow fiber microporous membrane made of the membrane material improved in Patent Document 2 relates to the mechanism of gas movement between the blood phase and the gas phase performed through the membrane, and is in the auxiliary circulation field that requires long-term continuous use. Even in application, it is said that sufficient plasma leakage resistance and stable and excellent gas exchange performance can be exhibited.

JP-A-5-42207 JP 2000-35557 A

  However, the conventional hollow fiber membrane made of a single type of membrane material as described above has sufficient gas exchange performance necessary to realize downsizing and so-called long-term durability that can be used for a long time without plasma leakage. In reality, it has been difficult to obtain a blood processing apparatus that sufficiently satisfies both sex requirements.

  In recent years, there has been a strong demand for the development of an artificial lung that can be used continuously for a long period of time for continuous cardiopulmonary assistance after surgery, respiratory assistance for premature infants, and cardiac assistance for patients with acute heart failure. Moreover, in order to reduce the load on the patient during the operation, there is a demand for the realization of a small oxygenator with excellent gas exchange efficiency that requires a small amount of blood filling and a small membrane area in contact with blood.

  Accordingly, the present invention provides a blood treatment that exhibits high gas exchange ability in the initial stage of use and enables miniaturization, and that stable gas exchange is possible by avoiding plasma leakage during long-term continuous use. An object is to provide an apparatus.

In order to solve the above problems, the blood treatment apparatus of the present invention comprises a dense module formed by arranging a plurality of dense hollow fiber membranes having a dense layer or a homogeneous layer, and a plurality of porous hollow fiber membranes. A porous module formed by arranging, a housing having a first gas exchange part and a second gas exchange part in which the dense module and the porous module are respectively stored in a laminated state, and the dense hollow fiber membrane And both ends of the two modules are sealed in a state in which the openings at both ends of the porous hollow fiber membrane are exposed, and the porous hollow fiber membrane and the dense hollow fiber membrane are disposed in an intermediate region between the both ends. A sealing member that extends in a direction intersecting with the axial direction of the first and second gas exchange portions to form a blood flow path, and faces the both ends of the blood flow path to the housing. Blood inlet port and blood provided And output port, and a supply port and an exhaust port, wherein the facing open ends of the sealing the dense hollow fiber membrane is exposed from member and the porous hollow fiber membrane disposed respectively in said housing, said porous Open / close means provided in at least one of the air supply port or the exhaust port of the module .

  According to the blood processing apparatus having the above-described configuration, the dense module and the porous module are housed in a stacked state in the same housing, and are arranged in series with respect to the blood flow path. Applicable.

  Therefore, the blood flow sequentially passes along the outer surface of the hollow fiber membrane of the dense module and the porous module, and in the initial stage of use, the porous module has excellent characteristics in terms of air bubble discharge and gas exchange performance during priming. Can be obtained. Moreover, if the gas exchange function with the porous module is stopped and only the gas exchange with the dense module is shifted to continuous use for a long time, plasma leakage is suppressed and the artificial oxygenator or blood circuit is replaced. In addition, oxygenation of extracorporeal blood can be continued. As a result, downsizing is possible and stable gas exchange is possible even during long-term continuous use.

Sectional drawing which shows the blood processing apparatus in embodiment of this invention The perspective view which showed the principal part of the blood processing apparatus in the partial cross section The perspective view which shows the other form of the principal part of the blood processing apparatus Sectional drawing which shows the artificial lung which is a blood processing apparatus of a prior art example

  The blood processing apparatus of the present invention can take the following aspects based on the above-described configuration.

That is, opening / closing means can be provided in both the air supply port and the exhaust port of the porous module.

  In addition, it is preferable that the first gas exchange unit is disposed closer to the blood inlet port than the second gas exchange unit.

  Further, the blood channel preferably has a circular cross section perpendicular to the channel direction.

  Moreover, it is preferable that the ratio of the oxygen transfer amount of the dense module to the oxygen transfer amount of the porous module in the region in the blood channel is in the range of 2.5 to 3.5.

  Also, the hollow fibers constituting the dense module and the porous module are arranged so that the axial directions of the hollow fibers are orthogonal to the flow direction of the blood flow path and the axial directions of the hollow fibers intersect each other. Can do.

  Moreover, it can be set as the structure by which at least one of the said 1st and 2nd gas exchange part is provided with two or more sets.

  The porous hollow fiber membrane can be formed using a polypropylene membrane, and the dense hollow fiber membrane can be formed using a polymethylpentene membrane or a silicone membrane.

(Embodiment)
A cross-sectional view of a blood processing apparatus in an embodiment of the present invention is shown in FIG. FIG. 2A is a perspective view showing the main part in a partial cross section. This blood processing apparatus includes a dense module 1 and a porous module 2.

  The dense module 1 is formed of a hollow fiber bundle in which a plurality of dense hollow fiber membranes 1a having a dense layer or a homogeneous layer are arranged. The porous module 2 is formed of a hollow fiber bundle in which a plurality of porous hollow fiber membranes 2a are arranged. As the membrane material of the dense hollow fiber membrane 1a, for example, a polymethylpentene membrane (dense membrane) or a silicone membrane (homogeneous membrane) can be used. As the membrane material of the porous hollow fiber membrane 2a, for example, a polypropylene (PP) membrane can be used.

  The housing 3 includes a first gas exchange unit 4 that houses the dense module 1 and a second gas exchange unit 5 that houses the porous module 2. The dense hollow fiber membrane 1a and the porous hollow fiber membrane 2a are arranged in a laminated state. That is, in the example of FIG. 1, the axial direction of the dense hollow fiber membrane 1a and the axial direction of the porous hollow fiber membrane 2a are parallel. However, if the dense hollow fiber membrane and the porous hollow fiber membrane have a laminated structure, the axial directions of the hollow fiber membranes do not necessarily have to be parallel to each other. For example, as shown in FIG. 2B, the dense hollow fiber membrane and the porous hollow fiber membrane are arranged in a state substantially orthogonal to the direction of the blood flow path, and the dense hollow fiber membrane is a porous hollow fiber membrane. The aspect which cross | intersected with respect may be sufficient. Thereby, the space formed between the hollow fiber membrane bundles can be reduced, which is preferable.

  Both end portions of both modules 1 and 2 are sealed by a sealing member 6 formed of a polymer potting material such as polyurethane, silicone, epoxy resin or the like. A state in which the housing 3 is removed is shown in a partially sectional view in FIG. 2A so that the structure formed by the sealing member 6 can be easily understood.

  In this sealing structure, the openings 7 at both ends of the dense hollow fiber membrane 1 a and the porous hollow fiber membrane 2 a are exposed without being closed by the sealing member 6. Accordingly, gas passages that pass through both ends of the hollow fiber membrane are secured in the dense hollow fiber membrane 1a and the porous hollow fiber membrane 2a, respectively. Further, the sealing member 6 forms a blood flow path 8 in an intermediate region between both end portions of both the modules 1 and 2. The blood flow path 8 is formed so as to extend in a direction intersecting the axial direction of the dense hollow fiber membrane 1a and the porous hollow fiber membrane 2a and pass through the first and second gas exchange portions 4, 5. The cross-sectional shape orthogonal to the flow path direction is a circle.

  The housing 3 further has blood inflow ports 9 and blood outflow ports 10 facing both ends of the blood flow path 8. Further, facing the openings 7 at both ends of the dense hollow fiber membrane 1 a and the porous hollow fiber membrane 2 a exposed from the sealing member 6, supply to the side portions of the first and second gas exchange portions 4 and 5, respectively. Air ports 11a and 11b and exhaust ports 12a and 12b are provided.

  Further, a partition wall 13 is provided on the inner wall of the housing 3 at the boundary between the first and second gas exchange portions 4 and 5. Thereby, in the 1st gas exchange part 4 and the 2nd gas exchange part 5, the space mutually isolated in the area | region which faced the supply ports 11a and 11b, respectively is formed. Similarly, spaces isolated from each other are also formed in regions facing the exhaust ports 12a and 12b, respectively. Accordingly, the air supply ports 11a and 11b and the exhaust ports 12a and 12b function independently of each other. At this time, the partition wall 13 is necessary for space separation as described above, but the thickness and shape thereof do not cause a space between the laminated dense hollow fiber membrane 1a and the porous hollow fiber membrane 2a. It is desirable to devise.

  Thereby, the gas exchange in the 1st gas exchange part 4 and the 2nd gas exchange part 5 can be selected suitably, and can be made to function. For example, if the exhaust port 12b of the second gas exchange unit 4 is closed by the clamp 14, the gas exchange function by the porous module 2 can be stopped. In the present embodiment, an example in which the clamp 14 is provided only in the exhaust port 12b is illustrated. However, by providing the clamp 14 also in the air supply port 11b, plasma leakage from the porous hollow fiber membrane 2a is more reliably performed. Since it can prevent, it is preferable. Thereby, when the gas exchange capacity is excessive or when the performance is lowered, the use of the portion can be interrupted without stopping the blood flow. In addition, when the membrane material is hydrophilized due to blood denaturation and plasma leaks from the hollow fiber, the gas flow can be stopped only on the module side that has deteriorated in performance without stopping the blood flow. .

  As described above, in the blood processing apparatus of the present embodiment, the dense module 1 and the porous module 2 are arranged in a laminated state in the common housing 3 and arranged in series with respect to the blood flow path 8. It is in a state. A so-called external perfusion method is used in which blood flows through the outer surface of the hollow fiber membranes 1a and 1b and oxygen-containing gas flows through the hollow fiber membranes 1a and 1b. In addition, an operation to stop the gas exchange function by the porous module 2 is possible. The effects based on such a configuration are as follows.

  First, in the initial stage of use, the porous module 2 can provide excellent characteristics in terms of bubble discharge during priming and gas exchange performance. Moreover, if the gas exchange function by the porous module 2 is stopped and only the gas exchange by the dense module 1 is shifted to the continuous use for a long time, plasma leakage is suppressed and the artificial oxygenator or blood circuit is exchanged. Without this, oxygenation of the extracorporeal blood can be continued.

  That is, it is known that when extracorporeal circulation such as auxiliary circulation is performed, plasma leakage occurs due to a decrease in hydrophobicity of the hollow fiber membrane due to degeneration of the blood of the patient. In such a case, while the porous hollow fiber membrane 2a is excellent in gas exchange capability, plasma leakage occurs and the gas exchange membrane area is lost. On the other hand, by closing the air supply port 11b or the exhaust port 12b to the fractionated second gas exchange unit 5, gas exchange and plasma leakage can be selectively stopped. Continuous treatment is possible without changing the lungs.

  After such a state is reached, the gas exchange performance is maintained only in the remaining dense hollow fiber membrane 1a. In general, patients immediately after the start of assisted circulation require a lot of gas exchange, so they often need maximum capacity, but once they are stable and require long-term assistance, their own cardiopulmonary function may be slightly However, it is often maintained (if it is not maintained, auxiliary lifesaving is difficult). In such a state, since there is often an auxiliary circulation state that does not necessarily require the maximum capacity of the oxygenator, there is no problem if a gas exchange performance of about 3/4 is maintained.

  In addition, the membrane area can be reduced by a porous hollow fiber membrane that is superior in gas exchange capacity compared to an artificial lung that is composed entirely of a uniform layer membrane. Thereby, the entire foreign matter wetted area (film area) is reduced, the filling amount can be reduced, and the invasiveness to the patient is reduced.

  In addition, since the first gas exchange unit 4 in which the dense module 1 is housed is disposed on the blood inflow port 9 side, blood exchanges gas with the dense hollow fiber membrane 1a (for example, a silicone membrane). After the gas is further exchanged by the porous hollow fiber membrane 2a (for example, PP membrane) on the outlet side, the gas flows out from the blood outflow port 10.

  By arranging in this order, it is possible to treat the bubble removal operation that tends to remain between the hollow fiber membranes during the priming operation with a porous hollow fiber membrane that has better bubble removal performance than the dense hollow fiber membrane. . Thereby, the priming time is shortened as compared with the case where only the dense hollow fiber membrane is used. That is, by disposing a porous hollow fiber membrane with excellent air bubble discharging performance on the blood outflow side, air bubbles remaining in the artificial lung are discharged from the pores of the membrane, so that the priming operation is simplified and even in an emergency. Improved operability can be expected.

  Further, by using the dense module 1 and the porous module 2 in combination, the blood processing apparatus can be downsized. The reason is as follows. First, the artificial lung used in the auxiliary circulation region is generally required to have a performance of a maximum blood flow rate of about 4 L / min. However, this is a flow rate required immediately after the start of the auxiliary circulation in a cardiopulmonary arrest state. On the other hand, once the pulsation resumes, it is common to use a support such as a ventilator and to reduce the flow rate so as not to interfere with the self-beat, and is often operated at 3 L / min or less. . Therefore, when the maximum flow rate is used, a membrane material that excels in minimum gas exchange is used together, and during long-term assistance, a membrane material that can cover only the required flow rate is arranged to reduce the required volume of the hollow fiber membrane. be able to.

  As a ratio when using two types of hollow fiber membranes together, the ratio of the oxygen transfer amount of the dense module 1 to the oxygen transfer amount of the porous module 2 in the region in the blood channel 8 is 2.5-3. It is desirable to set the value within a range of .5. When the proportion of the dense module 1 is small, there is a concern that the gas exchange capacity is insufficient during long-term (blood) circulation. On the other hand, if the proportion of the dense module 1 is too large, it becomes over-specification and is not only wasted, but also has a demerit that the blood filling amount of the entire module becomes large. This is because the dense module 1 has a smaller oxygen transfer amount than the porous module 2. As an example, in a blood processing apparatus with a maximum blood flow rate of 4 L / min, the PP film is 1 L / min (25%) and the silicone film is 3 L / min (75%). Considering the general blood flow rate of 3 L / min at the time of operation after resumption of pulsation with respect to the general maximum blood flow rate of about 4 L / min immediately after the start of the auxiliary circulation, if it is set in such a range, It is effective for miniaturization without affecting the operation of the system.

  The cross-sectional shape of the blood flow path 8 may be a square, but is preferably a circular shape with higher efficiency.

  Further, by arranging the dense module 1 and the porous module 2 in a laminated type and different membrane materials in the circular flow path, a straight flow path with fewer steps can be formed.

  In the above embodiment, one each of the first gas exchange unit 4 and the second gas exchange unit 5 is provided. However, at least one of the first and second gas exchange units is provided with a plurality of sets. It is also possible to do.

  A heat exchanger can also be incorporated into the artificial lung using the blood processing apparatus of the present invention.

  According to the blood processing apparatus of the present invention, a high gas exchange ability at the initial stage of use and avoidance of plasma leakage during continuous use for a long time can be achieved, and a small and stable gas exchange can be achieved. Useful for artificial lungs placed in

DESCRIPTION OF SYMBOLS 1 Dense module 1a Dense hollow fiber membrane 2 Porous module 2a Porous hollow fiber membrane 3 Housing 4 1st gas exchange part 5 2nd gas exchange part 6 Sealing member 7 Opening 8 Blood flow path 9 Blood inflow port 10 Blood Outflow port 11a, 11b Air supply port 12a, 12b Exhaust port 13 Partition 20 Housing 21 Tubular body 22, 23 Mounting cover 26, 27 Partition 28 Gas chamber 29 Inlet 30 Outlet 25 Hollow fiber membrane 24 Hollow fiber bundles 31, 32 Channel forming member 33 Blood inflow chamber 34 Blood outflow chamber 35 Blood inlet 36 Blood outlet

Claims (8)

A dense module formed by a hollow fiber bundle in which a plurality of dense hollow fiber membranes having a dense layer or a homogeneous layer are arranged;
A porous module formed by a bundle of hollow fibers in which a plurality of porous hollow fiber membranes are arranged;
A housing having a first gas exchange part and a second gas exchange part in which the dense module and the porous module are respectively housed in a stacked state;
Both ends of both modules are sealed in a state in which openings at both ends of the dense hollow fiber membrane and the porous hollow fiber membrane are exposed, and the porous hollow fiber membrane and A sealing member that extends in a direction intersecting the axial direction of the dense hollow fiber membrane and forms a blood flow path that passes through the first and second gas exchange parts;
A blood inflow port and a blood outflow port provided in the housing facing both ends of the blood flow path;
An air supply port and an exhaust port respectively provided in the housing facing openings at both ends of the dense hollow fiber membrane and the porous hollow fiber membrane exposed from the sealing member ;
A blood processing apparatus comprising: opening / closing means provided in at least one of an air supply port and an exhaust port of the porous module . Wherein both the air supply and exhaust ports of the porous module, the blood processing apparatus of claim 1 provided with a closing means.   The blood processing apparatus according to claim 1, wherein the first gas exchange unit is disposed closer to the blood inlet port than the second gas exchange unit. It said blood flow path, blood processing apparatus according to any one of claims 1 to 3 has a circular cross section perpendicular to the flow direction. For oxygen transfer amount of the porous module in the region of the blood flow path, the ratio of the oxygen transfer of the dense module, one of the claims 1-4 is in the range of 2.5 to 3.5 1 The blood processing apparatus according to Item. The axial direction of each hollow fiber constituting the dense module and the porous module is arranged so as to be orthogonal to the flow direction of the blood flow path, and the axial directions of the hollow fibers intersect each other. The blood processing apparatus according to any one of 1 to 5 . Wherein at least one of the first and second gas exchange unit, a blood treatment apparatus according to any one of claims 1 to 6 is provided with a plurality of sets. The porous hollow fiber membrane is formed using a polypropylene membrane, and the dense hollow fiber membrane is formed using a polymethylpentene membrane or a silicone membrane according to any one of claims 1 to 7 . Blood processing device.

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