Port for body fluid circulation

Abstract

To provide a port for body fluid circulation capable of efficiently executing injection and discharge of a liquid while suppressing a load applied to a patient.SOLUTION: A port 4 for body fluid circulation comprises: a distal end part 41 inserted through a hole 56 into a storage cavity 55 in which a body fluid is stored, having a circulation port 411 in which the body fluid is circulated and having a flow passage 412 communicating with the circulation port 411 and passing the body fluid; a fitting part 42 fitted with the hole 56, having an internal space 423 divided by a cylindrical outer wall 421 and a cylindrical inner wall 422 and connected to the flow passage 412, and having an insertion portion 424 for passing a medical appliance 31 into the cranium inside the inner wall 422; and a proximal end part 43 disposed outside an organism and having a chamber 431 connected to the internal space 423 and receiving the body fluid.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a body fluid communication port used in the treatment of brain diseases. [Background technology]

[0002] When a brain disease, such as cerebral infarction, occurs, the blood flow that supplies oxygen to brain cells is blocked, potentially damaging the brain cells. Therefore, when a cerebral infarction occurs, early reperfusion of blood flow is necessary. Patent Document 1 proposes a treatment for cerebral infarction, in which oxygenated cerebrospinal fluid or other fluid is injected into the patient's body cavity where the cerebrospinal fluid is present and then discharged outside the body cavity to circulate the fluid and directly supply oxygen to oxygen-deficient brain cells. The required volume of oxygenated cerebrospinal fluid or other fluid is greater than the amount of medication required for general medical treatment or for treatments involving the administration of drug solutions, such as anesthesia. Therefore, infusion and discharge routes must be established to suppress intracranial pressure fluctuations.

[0003] Common locations for accessing the cavity containing cerebrospinal fluid from outside the living body include the lumbar spine, the ventricles, and the cisterns. However, there are advantages and disadvantages to using the lumbar spine, the ventricles, and the cisterns as locations for accessing the cavity containing cerebrospinal fluid from outside the living body, as follows:

[0004] Specifically, using the lumbar spine as a site for accessing the cerebrospinal fluid cavity from outside the body has the advantage of reducing the burden on the patient, since the cerebrospinal fluid cavity can be accessed simply by puncturing with a device. However, due to the distance between the lumbar spine (puncture site) and the brain (treatment site), it takes a certain amount of time for the fluid injection effect to be achieved. Furthermore, as mentioned above, the large fluid dose and flow rate required for treatment necessitates the insertion of a medical device such as a catheter with a diameter of 14G (gauge) or more. However, the narrow lumbar spinal passage makes it difficult to insert a needle of 14G or more. Additionally, treatment requires both an infusion route and a drainage route, but as mentioned above, the narrow lumbar spinal passage makes it difficult to provide both an infusion route and a drainage route with sufficient diameter.

[0005] The use of ventricles and cisterns as a means of accessing the cerebrospinal fluid storage cavity from outside the body has the advantage that fluid can be directly supplied to the brain, allowing for rapid injection and drainage. However, accessing the ventricles and cisterns requires puncturing a device into the head or performing a craniotomy (removal of part of the skull), placing a significant burden on the patient. For example, the need for an injection route and a drainage route necessitates the insertion of two devices. Furthermore, when accessing the spinal cavity from the ventricles and cisterns or through lumbar puncture or other methods, the drainage catheter used to drain fluid outside the body cavity can become blocked by blood clots, tissue fragments, or tissue adhesions resulting from bleeding during the puncture or puncture. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2023 / 181979 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a bodily fluid circulation port that can efficiently inject and discharge liquid while minimizing the burden on the patient. [Means for solving the problem]

[0008] The present invention provides (1) a bodily fluid circulation port that is used by fitting into a hole formed in the surface of a living body, the bodily fluid circulation port comprising: a tip portion that passes through the hole and is inserted into a housing cavity containing bodily fluid, and has a circulation port through which the bodily fluid flows and a flow path that communicates with the circulation port and through which the bodily fluid flows; a fitting portion that fits into the hole, has an internal space that is partitioned by a cylindrical outer wall and a cylindrical inner wall and is connected to the flow path, and has an insertion portion on the inside of the inner wall for passing a medical device into the skull; and a base portion that is placed outside the living body, is connected to the internal space, and has a chamber that receives the bodily fluid.

[0009] According to the bodily fluid circulation port of (1) above, the tip portion is inserted into the interior of the receiving cavity containing bodily fluid through a hole formed in the surface of the living body. The fitting portion fits into the hole formed in the surface of the living body and has an insertion portion on the inside of the inner wall for passing the medical device into the skull. The fitting portion also has an internal space defined by a cylindrical outer wall and a cylindrical inner wall. The internal space of the fitting portion is connected to a flow path for passing liquids such as bodily fluids and therapeutic agents that flow through the flow port in the tip portion. The base portion is disposed outside the living body and has a chamber. The chamber at the base portion is connected to the internal space of the fitting portion and receives the bodily fluid.

[0010] Therefore, with the bodily fluid port of (1) above, for example, an injection device serving as a medical instrument for injecting a liquid into a bodily fluid storage cavity is passed through the insertion portion of the fitting into the skull, and the bodily fluid stored in the storage cavity is guided from the flow port at the tip end through a flow path and the internal space of the fitting into a chamber at the base end, thereby enabling the injection and discharge of liquid through a single hole formed on the surface of the living body. As a result, the bodily fluid port of (1) above can reduce the burden on the patient.

[0011] Furthermore, the bodily fluid discharge path does not use a catheter, but rather utilizes the flow path at the tip inserted into the housing cavity, the internal space of the fitting that fits with the hole formed on the surface of the living body, and the chamber at the base end located outside the living body. Therefore, blockage of the bodily fluid discharge path can be prevented. This allows the bodily fluid port described in (1) above to efficiently inject and discharge liquid. It is also possible to discharge bodily fluids using a catheter or the like, and use the above-described bodily fluid discharge path to inject a liquid such as a medicinal solution into the housing cavity from outside the living body. In this case, the bodily fluid port described in (1) above still has the same effects as described above.

[0012] (2) In the bodily fluid port of (1) above, it is preferable that the base end further has a communication port connected to the chamber and communicating with the outside of the chamber.

[0013] According to the bodily fluid port of (2) above, the bodily fluid received in the chamber at the base end is reliably communicated with the outside of the chamber through the communication port at the base end, thereby enabling the bodily fluid port of (2) above to more efficiently inject and discharge liquid.

[0014] (3) In the bodily fluid circulation port of (1) or (2) above, it is preferable that the flow path is a first flow path, and the internal space is a second flow path for communicating with the outside of the living body.

[0015] According to the bodily fluid port of (3) above, the flow path at the tip end through which the bodily fluid that has flowed through the flow port passes is the first flow path. The internal space of the fitting portion, partitioned by the cylindrical outer wall and the cylindrical inner wall, is the second flow path for communicating with the outside of the living body. Therefore, the bodily fluid that has flowed through the flow port flows smoothly through the first and second flow paths and is guided to the chamber at the base end. This allows the bodily fluid port of (3) above to inject and discharge liquid more efficiently.

[0016] (4) In the body fluid circulation port of any of (1) to (3) above, the base end is preferably made of a flexible material and is deformable in response to fluctuations in the internal pressure caused by the body fluid.

[0017] According to the bodily fluid circulation port of (4) above, the proximal end is deformable in response to fluctuations in intravital pressure caused by bodily fluids. That is, the chamber at the proximal end functions as a buffer that absorbs fluctuations in intravital pressure, ensuring compliance of the receiving cavity in which the bodily fluid is contained. "Compliance" refers to the adaptability that allows the intravital pressure to be maintained by deformation based on the dynamic flexibility of the receiving cavity (e.g., the subarachnoid space) in response to certain changes in intravital volume.

[0018] (5) In any of the bodily fluid flow ports (1) to (4) above, it is preferable that the tip portion has a flare portion that is flared outward in the radial direction from the fitting portion, and the end of the flare portion has the flow port.

[0019] According to the bodily fluid port of (5) above, the tip portion has a flared portion that flares outward in the radial direction from the fitting portion, and therefore functions as an anchor after being inserted into the bodily fluid cavity. Therefore, the tip portion can prevent the bodily fluid port from slipping out of the hole formed on the surface of the living body when the bodily fluid flows into the flow path from the flow port at the end of the flared portion. Furthermore, because the flow port of the tip portion is located at the tip of the flared portion that flares outward in the radial direction, the bodily fluid can be discharged from all directions around the circumference. Therefore, it is possible to prevent the flow path of the bodily fluid or the injection liquid from being blocked and becoming unable to flow due to blood clots, tissue fragments, or tissue adhesion caused by bleeding that occurs when forming the hole on the living body surface. This allows the bodily fluid port of (5) above to efficiently inject and discharge liquid.

[0020] (6) In the bodily fluid port according to any one of (1) to (4), the tip portion has a plurality of branch portions that branch out and expand radially outward from the fitting portion, It is preferable that the end of the branch portion has the flow port.

[0021] According to the bodily fluid port of (6) above, the tip portion has a plurality of branch portions that branch outward in the radial direction from the fitting portion and spread outward, and therefore functions as an anchor after being inserted into the bodily fluid storage cavity. Therefore, the tip portion can prevent the bodily fluid storage port from slipping out of the hole formed on the surface of the living body when the bodily fluid flows into the flow path from the flow opening at the end of the branch portion, or when a liquid such as a medicinal solution is injected into the storage cavity from outside the living body via the chamber. Furthermore, because the plurality of branch portions branch outward in the radial direction from the fitting portion and spread outward, it is easy for a medical professional to insert the tip portion into the bodily fluid storage cavity through the hole opened by trepanation.

[0022] (7) In any of the bodily fluid flow ports (1) to (6) above, it is preferable that the fitting portion has a valve body provided in the insertion portion to prevent fluid inside the living body from leaking to the outside of the living body.

[0023] According to the bodily fluid port of (7) above, the valve provided in the insertion portion for passing a medical device into the skull prevents fluid inside the living body from leaking to the outside of the living body. Therefore, when the bodily fluid port is fitted into a hole formed on the surface of the living body, fluctuations in intracorporeal pressure due to fluid leakage can be suppressed. In addition, the valve prevents bodily fluids present in the accommodation cavity from coming into contact with air, thereby reducing the risk of infection without the need to create a subcutaneous tunnel. Furthermore, the valve holds the device inserted into the insertion portion, making it possible to fix the device at a predetermined insertion position.

[0024] (8) In the body fluid passage port of any of the above (1) to (7), the hole is preferably a hole formed by trepanning the head, and the body fluid is cerebrospinal fluid. [Effects of the Invention]

[0025] According to the present invention, it is possible to provide a bodily fluid circulation port that can efficiently inject and discharge liquid while reducing the burden on the patient. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a schematic diagram showing a liquid circulation system in which a bodily fluid circulation port according to the present embodiment is used. [Figure 2] 1 is a schematic diagram showing a liquid discharge system in which a bodily fluid circulation port according to an embodiment of the present invention is used. [Figure 3] 1 is a perspective view showing a bodily fluid circulating port according to a first embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view taken along the cutting plane AA shown in FIG. [Figure 5] FIG. 10 is a cross-sectional view showing a bodily fluid circulating port according to a first modified example of the present embodiment. [Figure 6] FIG. 10 is a cross-sectional view showing a bodily fluid circulating port according to a second modified example of the present embodiment. [Figure 7] FIG. 10 is a perspective view showing a bodily fluid circulating port according to a second embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view taken along the cutting plane BB shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0027] Preferred embodiments of the present invention will now be described in detail with reference to the drawings. The embodiments described below are preferred examples of the present invention, and therefore various technically preferable limitations are applied thereto, but the scope of the present invention is not limited to these aspects unless otherwise specified in the following description to the effect that the present invention is particularly limited. Furthermore, in each drawing, similar components are designated by the same reference numerals, and detailed descriptions thereof will be omitted as appropriate.

[0028] FIG. 1 is a schematic diagram showing a liquid circulation system in which a bodily fluid circulation port according to this embodiment is used. The fluid circulation system 2 shown in FIG. 1 circulates a fluid by injecting a fluid into a cavity containing the subject's cerebrospinal fluid (CSF) and then discharging the fluid to the outside of the cavity. Cerebrospinal fluid is primarily contained in the subarachnoid space and ventricles. That is, the cavities containing cerebrospinal fluid include the subarachnoid space and ventricles. One type of subarachnoid space includes cisterns such as the basilar cistern, but the specific location is not particularly limited. The cerebrospinal fluid in this embodiment is an example of the "body fluid" of the present invention.

[0029] The liquid injected into the cavity may be, for example, a liquid with an oxygen concentration higher than that of normal cerebrospinal fluid (i.e., a highly oxygenated solution). However, the liquid injected into the cavity is not limited to a highly oxygenated solution. For example, the liquid injected into the cavity may be a drug-containing liquid in which a drug has been added to cerebrospinal fluid during extracorporeal circulation, or may be cerebrospinal fluid that has been filtered to remove undesirable substances during extracorporeal circulation. Alternatively, the liquid injected into the cavity may be cerebrospinal fluid that has been subjected to some kind of treatment, such as irradiation with energy or heating.

[0030] Furthermore, in the initial stage of treatment, the liquid injected into the containing cavity may be artificial cerebrospinal fluid or a substitute for cerebrospinal fluid, such as physiological saline or lactated Ringer's solution. In this embodiment, artificial cerebrospinal fluid, substitutes such as physiological saline or lactated Ringer's solution, mixtures of artificial cerebrospinal fluid and substitutes such as physiological saline or lactated Ringer's solution, other medicinal solutions, and distilled water for injection may be collectively referred to as liquid. In the following description, for convenience of explanation, a case where the liquid injected into the containing cavity is a highly oxygenated solution may be given as an example.

[0031] 1, the liquid circulation system 2 includes an inlet line 21, an outlet line 22, a liquid delivery unit 23, and a bodily fluid circulation port 4. The liquid circulation system 2 may also include an oxygenation mechanism 24, an oxygen supply source 25, and a heat exchanger 26.

[0032] The infusion line 21 has an injection device 31 such as a catheter, and is inserted into the housing cavity through a bodily fluid communication port 4 installed in the subject's head. The fluid is then injected into the housing cavity as indicated by arrow A1 in FIG. 1 . As illustrated in FIG. 1 , the head to which the infusion line 21 is delivered may be, for example, a cerebral cistern, such as the basilar cistern, but is not limited thereto as long as it is near a treatment target site, such as a cerebral infarction lesion. In this case, the infusion line 21 is inserted into the housing cavity through the bodily fluid communication port 4 as indicated by arrow A2 in FIG. 1 . The tip of the catheter or the like is then delivered along the brain surface to the target site in the cistern and placed in the infusion device 31, where the fluid is then injected into the cistern. Alternatively, as illustrated in FIG. 1 , the head to which the infusion line 21 is delivered may be, for example, a cerebral ventricle. In this case, the infusion line 21 is inserted into the housing cavity through the bodily fluid communication port 4 as indicated by arrow A3 in FIG. 1 . Then, the tip of a catheter or the like is delivered to, for example, the lateral ventricle and placed in the injection device 31, which then injects the liquid into the ventricle. Note that the delivery of the injection device 31 may or may not penetrate the brain parenchyma depending on the delivery location, and a suitable method is selected accordingly. For example, an access route such as that used in general ventricular drainage or cisternal drainage procedures is preferred.

[0033] The discharge line 22 includes a discharge device 32 and is inserted into the bodily fluid port 4 or attached to the surface of the bodily fluid port 4. The cavity (e.g., the subarachnoid space and the ventricle) containing cerebrospinal fluid is a substantially closed space. A certain pressure, such as intracranial pressure, is applied inside the cavity. Therefore, when the bodily fluid port 4 is installed in the head and the discharge line 22 including the discharge device 32 is installed in the bodily fluid port 4, the discharge line 22 discharges the liquid (e.g., cerebrospinal fluid) from the cavity to the outside, as indicated by arrows A4 and A6 in FIG. 1 or arrows A5 and A6 in FIG. 1 . A filter for filtering impurities, a reservoir for temporarily storing cerebrospinal fluid to adjust intracranial pressure, or the like may be provided along the discharge line 22. The intracranial pressure in this embodiment is an example of the "intracellular pressure" of the present invention. The bodily fluid circulating port according to this embodiment will be described in detail later.

[0034] The oxygenation mechanism 24 is connected to the oxygen supply source 25 via the first pipe 271. The oxygenation mechanism 24 mixes a liquid such as cerebrospinal fluid supplied through the discharge line 22 with oxygen supplied from the oxygen supply source 25 through the first pipe 271, as indicated by arrow A7 in FIG. 1, to generate oxygenated cerebrospinal fluid.

[0035] The oxygenation mechanism 24 is also connected to the heat exchanger 26 via a second pipe 272 and a third pipe 273. As indicated by arrow A8 in FIG. 1 , the oxygenation mechanism 24 supplies oxygenated cerebrospinal fluid to the heat exchanger 26 via the second pipe 272. The heat exchanger 26 adjusts the temperature of the cerebrospinal fluid supplied from the oxygenation mechanism 24 via the second pipe 272. As indicated by arrow A9 in FIG. 1 , the heat exchanger 26 supplies the temperature-adjusted cerebrospinal fluid to the oxygenation mechanism 24 via the third pipe 273. The oxygenation mechanism 24 then supplies the oxygenated, temperature-adjusted cerebrospinal fluid as a highly oxygenated solution to the infusion line 21. An example of the oxygenation mechanism 24 is a hollow fiber membrane oxygenator for adding oxygen to blood.

[0036] The liquid delivery unit 23 is provided in the infusion line 21 and circulates the liquid supplied from the oxygenation mechanism 24. The liquid delivery unit 23 may be provided in the discharge line 22, or may be provided in both the infusion line 21 and the discharge line 22. Examples of the liquid delivery unit 23 include an infusion pump, a syringe pump, and a centrifugal pump. The method for delivering the liquid may be a method that utilizes free fall without using an infusion pump or the like.

[0037] As shown by arrow A1 in FIG. 1, the fluid delivery unit 23 delivers fluid to the infusion line 21, and the fluid is infused into the cavity from the subject's head through the infusion line 21. As described above, the cavity containing cerebrospinal fluid (e.g., the subarachnoid space and the ventricle) is a substantially closed space. A certain amount of pressure, such as intracranial pressure, is applied inside the cavity. Therefore, when the infusion line 21 injects fluid into the cavity, the fluid (e.g., cerebrospinal fluid) inside the cavity is pushed out of the cavity through the discharge line 22, including the discharge device 32, as shown by arrows A4 and A6 in FIG. 1 or arrows A5 and A6 in FIG. 1. In this manner, the fluid delivery unit 23 circulates the fluid.

[0038] Next, a liquid discharge system in which the bodily fluid circulation port according to this embodiment is used will be described. In addition, when the components of the liquid discharge system 2A described with reference to FIG. 2 are the same as the components of the liquid circulation system 2 described above with reference to FIG. 1, redundant explanations will be omitted as appropriate, and the following explanation will focus on the differences.

[0039] FIG. 2 is a schematic diagram showing a liquid discharge system in which a bodily fluid circulation port according to this embodiment is used. The liquid discharge system 2A shown in Figure 2 replaces the cerebrospinal fluid with a liquid by injecting a liquid into the interior of a storage cavity that contains the cerebrospinal fluid of a subject and discharging the cerebrospinal fluid to the exterior of the storage cavity.

[0040] 2, the liquid discharge system 2A includes an inlet line 21, an outlet line 22, and a bodily fluid circulation port 4. The liquid discharge system 2A may also include a liquid delivery section 23, a reservoir tank 27, and a storage section 28.

[0041] As described above with reference to FIG. 1 , a cavity (e.g., a subarachnoid space or a cerebral ventricle) containing cerebrospinal fluid is a substantially closed space. A certain pressure, such as intracranial pressure, is applied inside the cavity. Therefore, when the bodily fluid communication port 4 is installed in the head and the drain line 22 including the drain device 32 is installed in the bodily fluid communication port 4, the drain line 22 drains the liquid (e.g., cerebrospinal fluid) inside the cavity to the outside of the cavity, as indicated by arrows A4 and A7 in FIG. 1 or arrows A5 and A7 in FIG. 1 . The cerebrospinal fluid drained through the drain line 22 is supplied to a reservoir 28 located outside the living body.

[0042] Reservoir tank 27 stores a liquid to be injected into the interior of the accommodation cavity. Examples of the liquid stored in reservoir tank 27 are as described above with reference to Fig. 1 as the liquid to be injected into the interior of the accommodation cavity, such as highly oxygenated artificial cerebrospinal fluid.

[0043] The liquid delivery unit 23 is provided in the infusion line 21 and delivers the liquid supplied from the reservoir tank 27. The liquid delivery unit 23 may be provided in the discharge line 22, or may be provided in both the infusion line 21 and the discharge line 22. Examples of the liquid delivery unit 23 include an infusion pump, a syringe pump, and a centrifugal pump. Note that the liquid delivery unit 23 is not necessarily provided, and the liquid may be delivered by free fall or the like. Other configurations and operations are the same as those of the liquid circulation system 2 described above with reference to FIG.

[0044] Next, the bodily fluid circulating port according to this embodiment will be described in detail with reference to the drawings. FIG. 3 is a perspective view showing the bodily fluid circulating port according to the first embodiment of the present invention. FIG. 4 is a cross-sectional view taken along the cutting plane AA shown in FIG.

[0045] The bodily fluid circulation port 4 according to this embodiment is made of a flexible material and is used by fitting it into a hole made by trepanation. The "hole made by trepanation" in this embodiment is an example of the "hole made on the surface of a living body" of the present invention. The flexible material is not particularly limited as long as it is a polyolefin such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, styrene-ethylene-butylene-styrene copolymer, ionomer, or a mixture of two or more of these; a thermoplastic resin such as soft polyvinyl chloride resin, polyamide, polyamide elastomer, nylon elastomer, polyester, polyester elastomer, polyurethane, or fluororesin; silicone rubber; or latex rubber; with silicone rubber being preferred.

[0046] For example, as shown in Fig. 4, the bodily fluid communication port 4 is inserted and fitted into a hole 56 made by burr hole drilling, i.e., a hole 56 formed by penetrating a skull 51, a dura mater 52, and an arachnoid membrane 53. As shown in Figs. 3 and 4, the bodily fluid communication port 4 includes a distal end portion 41, a fitting portion 42, and a proximal end portion 43. The fitting portion 42 is disposed between the distal end portion 41 and the proximal end portion 43, and is connected to the distal end portion 41 on one side and to the proximal end portion 43 on the other side.

[0047] The tip portion 41 passes through the hole 56 and is inserted into the interior of the cavity containing cerebrospinal fluid. In the example shown in FIG. 4, the tip portion 41 passes through the hole 56 and is inserted into the subarachnoid space 55 between the arachnoid membrane 53 and the pia mater 54. The tip portion 41 has a flared shape that widens radially outward from the fitting portion 42 and has a flow port 411 and a flow path 412. In other words, the tip portion 41 has a flared portion 413 that widens radially outward from the fitting portion 42. In this case, since the tip portion 41 needs to be configured so that it can be inserted into the interior of the cavity containing cerebrospinal fluid, it is preferable that the thickness of the flared shape be smaller than the gap of the cavity. Since the thickness of the flared shape is smaller than the gap of the cavity, the flow of liquid at the tip portion 41 is not completely blocked, allowing for efficient injection and discharge of liquid.

[0048] An end of the flared portion 413 has a flow port 411. That is, the flow port 411 is formed at the end of the flared portion 413. As indicated by arrow A11 in FIG. 4 , cerebrospinal fluid present in the subarachnoid space 55 flows through the flow port 411 formed in the tip portion 41 and into the interior of the tip portion 41. The flow path 412 communicates with the flow port 411 and allows the cerebrospinal fluid that has flowed through the flow port 411 to pass through. The cerebrospinal fluid that has passed through the flow path 412 is led to the fitting portion 42. The flow path 412 of this embodiment is an example of the "first flow path" of the present invention.

[0049] The fitting portion 42 fits into the hole 56 and has a cylindrical outer wall 421 and a cylindrical inner wall 422. That is, as shown in FIG. 4, the fitting portion 42 has a double-pipe shape. An internal space 423 is formed between the cylindrical outer wall 421 and the cylindrical inner wall 422. The internal space 423 is a space partitioned by the outer wall 421 and the inner wall 422 and is a space connected to the flow path 412 of the distal end portion 41. As indicated by arrow A12 in FIG. 4, cerebrospinal fluid guided from the flow path 412 of the distal end portion 41 passes through the internal space 423 of the fitting portion 42 and is guided to the base end portion 43.

[0050] An insertion portion 424 is formed on the inside of the inner wall 422 of the fitting portion 42. The insertion portion 424 functions as a passage for passing a medical device into the skull. The "medical device" referred to here is, for example, the injection device 31 described above with reference to FIGS. 1 and 2. Examples of the injection device 31 include a catheter and a tube. The medical device passing through the insertion portion 424 may be, for example, the drainage device 32 described above with reference to FIGS. 1 and 2. In this case, the liquid flows through the flow port 411 and is injected into the subarachnoid space 55, and the cerebrospinal fluid is discharged to the outside of the subarachnoid space 55 by the drainage device 32 that has passed through the insertion portion 424. In the description of this embodiment, a case in which the injection device 31 passes through the insertion portion 424 will be exemplified.

[0051] Fitting portion 42 further includes valve body 425. Valve body 425 is provided in insertion portion 424 and is made of a flexible material. Valve body 425 prevents fluid (e.g., cerebrospinal fluid) inside the living body from leaking to the outside. As shown in FIG. 4, valve body 425 allows injection device 31 to pass through. Therefore, as shown by arrow A14 in FIG. 4, injection device 31 inserted into insertion portion 424 and passing through valve body 425 can inject liquid into subarachnoid space 55. Valve body 425 can be configured, for example, as a hemostatic valve, a torque device, or a similar structure, or as a membrane made of a thermoplastic resin such as polyvinylidene chloride, vinyl chloride resin, polymethylpentene, polyethylene, or fluororesin, or as a membrane made of silicone rubber, latex rubber, or the like. The configuration of valve body 425 is not particularly limited as long as it is capable of preventing leakage of cerebrospinal fluid.

[0052] The base end 43 is disposed outside the living body and includes a chamber 431. The chamber 431 is connected to the internal space 423 of the fitting 42 and receives cerebrospinal fluid that has passed through the internal space 423. The volume of cerebrospinal fluid that can be received in the chamber 431 is approximately 1 mL to 50 mL, as long as it can be supported by the strength of the joint between the fitting 42 and the base end 43. The base end 43 is formed of a flexible material and is deformable in response to fluctuations in intracranial pressure. That is, the chamber 431 of the base end 43 functions as a buffer that absorbs fluctuations in intracranial pressure and ensures compliance of the receiving cavity that receives the cerebrospinal fluid. In this specification, "compliance" refers to the adaptability that allows the intracranial pressure to be maintained by, for example, deformation based on the dynamic flexibility of the receiving cavity (e.g., the subarachnoid space 55) in response to certain changes in the intracranial volume.

[0053] 4, a needle 32A, which is an example of the discharge device 32 described above with reference to, for example, FIGS. 1 and 2, is inserted into the proximal end 43. The tip of the needle 32A is placed in the chamber 431. As indicated by arrow A13 in FIG. 4, the cerebrospinal fluid received by the chamber 431 passes through the lumen of the needle 32A and is discharged to the outside of the living body.

[0054] Next, the flow of the liquid will be described. When the bodily fluid communication port 4 is placed in the head and the needle 32A is inserted into the proximal end 43, cerebrospinal fluid present in the subarachnoid space 55 flows through the communication port 411 of the distal end 41, into the interior of the distal end 41, and flows through the flow path 412 of the distal end 41, as indicated by arrows A11 and A12 in Fig. 4. Alternatively, when the bodily fluid communication port 4 is placed in the head and the needle 32A is inserted into the proximal end 43, and liquid is injected into the subarachnoid space 55 through the injection device 31, as indicated by arrow A14 in Fig. 4, cerebrospinal fluid present in the subarachnoid space 55 flows through the communication port 411 of the distal end 41, into the interior of the distal end 41, and flows through the flow path 412 of the distal end 41, as indicated by arrows A11 and A12 in Fig. 4.

[0055] The cerebrospinal fluid that has passed through the flow path 412 flows through the internal space 423 of the fitting portion 42 and is led to the chamber 431 of the base end portion 43. As indicated by the arrow A13 in FIG. 4, the cerebrospinal fluid received in the chamber 431 passes through the lumen of the needle 32A and is discharged to the outside of the living body.

[0056] In this way, the internal space 423 of the fitting portion 42 functions as a flow path for discharging cerebrospinal fluid to the outside of the living body. The internal space 423 of this embodiment is an example of the "second flow path" of the present invention.

[0057] As described above, with bodily fluid communication port 4 according to this embodiment, for example, injection device 31, a medical instrument for injecting a liquid into a cerebrospinal fluid storage cavity, is passed through insertion portion 424 of fitting portion 42 into subarachnoid space 55, and the cerebrospinal fluid stored in the storage cavity is guided from communication port 411 of distal end portion 41 through flow path 412 and internal space 423 of fitting portion 42 into chamber 431 of base end portion 43, whereby liquid can be injected and discharged with a single puncture. As a result, bodily fluid communication port 4 according to this embodiment can reduce the burden on the patient.

[0058] Furthermore, the cerebrospinal fluid drainage path does not involve a catheter, but rather utilizes the flow path 412 of the tip portion 41 inserted into the housing cavity, the internal space 423 of the fitting portion 42 mated with the hole 56, and the chamber 431 of the base end portion 43 positioned outside the living body. The flow port 411 of the tip portion 41 is located at the flared tip, which widens radially outward, allowing cerebrospinal fluid to be drained from all directions around the circumference. This prevents blockage of the cerebrospinal fluid drainage path due to blood clots, tissue fragments, or tissue adhesion caused by bleeding during burr hole drilling. This allows the bodily fluid port 4 of this embodiment to efficiently inject and drain liquid. Furthermore, either injection or drainage can be performed deep in the brain using a medical device such as a catheter inserted through the insertion portion 424, and the other injection or drainage can be performed through the tip portion 41 positioned near the brain surface. This allows the injection and drainage sites to be sufficiently separated, preventing the injected therapeutic liquid from being immediately drained, resulting in a high therapeutic effect.

[0059] Furthermore, since the internal space 423 of the fitting portion 42 functions as a flow path for discharging cerebrospinal fluid to the outside of the living body, the cerebrospinal fluid that has passed through the flow port 411 of the tip portion 41 flows smoothly through the flow path 412 of the tip portion 41 and the internal space 423 of the fitting portion 42, and is led to the chamber 431 of the base end portion 43. This allows the bodily fluid passage port 4 according to this embodiment to inject and discharge liquid even more efficiently.

[0060] Furthermore, tip portion 41 has flare portion 413 that has a flared shape that widens radially outward from fitting portion 42, and therefore functions as an anchor after being inserted into subarachnoid space 55. Therefore, tip portion 41 can prevent bodily fluid circulation port 4 from slipping out of hole 56 when cerebrospinal fluid flows from circulation port 411 at the end of flared portion 413 toward flow path 412.

[0061] Furthermore, valve body 425 prevents fluid inside the living body (e.g., cerebrospinal fluid) from leaking to the outside of the living body, and therefore can prevent fluctuations in intracranial pressure due to fluid leakage when bodily fluid communication port 4 is fitted into hole 56. Valve body 425 also prevents cerebrospinal fluid present inside subarachnoid space 55 from coming into contact with air, thereby reducing the risk of infection even without creating a subcutaneous tunnel. Furthermore, valve body 425 holds injection device 31 inserted into insertion portion 424, making it possible to fix injection device 31 at a predetermined insertion position.

[0062] Next, a bodily fluid circulating port according to a modified example of this embodiment will be described with reference to the drawings. In addition, in cases where the components of the bodily fluid circulating port according to a modified example of this embodiment are the same as the components of the bodily fluid circulating port 4 according to this embodiment described above with reference to Figures 3 and 4, duplicated explanations will be omitted as appropriate, and the following explanation will focus on the differences.

[0063] FIG. 5 is a cross-sectional view showing a bodily fluid circulating port according to a first modified example of the present embodiment. FIG. 5 corresponds to a cross-sectional view taken along the cutting plane AA shown in FIG.

[0064] The bodily fluid circulating port 4A according to this example includes a tip portion 41, a fitting portion 42, and a base end portion 43 A. The tip portion 41 and the fitting portion 42 are as described above with reference to FIGS.

[0065] The base end portion 43A has a communication port 432. The communication port 432 connects the inside of the chamber 431 to the outside of the chamber 431, and discharges the cerebrospinal fluid received in the chamber 431 to the outside of the chamber 431. That is, the cerebrospinal fluid received in the chamber 431 passes through the communication port 432 and is discharged to the outside of the chamber 431. As described above with reference to FIGS. 3 and 4 , when the liquid flows through the communication port 411 and is injected into the subarachnoid space 55 (that is, when the discharge device 32 passes through the insertion portion 424), the liquid passes through the communication port 432 and flows into the chamber 431.

[0066] As shown in FIG. 5, as an example of the drainage device 32 described above with reference to FIGS. 1 and 2, a tube 32B is attached to the outer surface of the base end 43A. The tube 32B may be attached by any method as long as it allows cerebrospinal fluid to be discharged without leaking to the outside, and UV adhesive bonding may be used as an example. The inner lumen of the tube 32B is connected to the communication port 432. Therefore, as shown by arrow A15 in FIG. 5, the cerebrospinal fluid received in the chamber 431 passes through the communication port 432 of the base end 43A, flows through the inner lumen of the tube 32B, and is discharged to the outside of the living body. The rest of the structure is the same as that of the bodily fluid circulation port 4 described above with reference to Figures 3 and 4. The tube 32B may have a structure including a connector portion that can be connected to another medical device such as a catheter. When the tube 32B has such a structure, it becomes easier to perform predetermined treatments on the cerebrospinal fluid after it has been discharged.

[0067] According to the bodily fluid circulating port 4A of this modification, the communication port 432 is provided in the base end portion 43 and connects the inside of the chamber 431 to the outside of the chamber 431, so that the cerebrospinal fluid received in the chamber 431 of the base end portion 43 is reliably discharged to the outside of the chamber 431 through the communication port 432 of the base end portion 43. This allows the bodily fluid circulating port 4A of this example to inject and discharge liquid more efficiently. In addition, the same effects as those of the bodily fluid circulating port 4 described above with reference to FIGS. 3 and 4 can be obtained.

[0068] FIG. 6 is a cross-sectional view showing a bodily fluid circulating port according to a second modified example of the present embodiment. FIG. 6 corresponds to a cross-sectional view taken along the line AA in FIG.

[0069] The bodily fluid circulating port 4B according to this example includes a tip portion 41, a fitting portion 42, and a base end portion 43B. The tip portion 41 and the fitting portion 42 are as described above with reference to FIGS.

[0070] The base end portion 43B has an expansion portion 433. The expansion portion 433 is formed, for example, in a ring shape near the entrance of the insertion portion 424, and is thinner than the thickness of other portions of the base end portion 43B. Therefore, as shown by the expansion portion 433 indicated by the two-dot chain line in FIG. 6, when cerebrospinal fluid is received in the chamber 431, the expansion portion 433 expands toward the inside of the inner wall 422, i.e., toward the inside of the insertion portion 424. Then, the insertion portion 424 is blocked by the expansion portion 433. In other words, the expansion portion 433 expands due to the chamber 431 receiving cerebrospinal fluid, and blocks the expansion portion 433.

[0071] In this way, expansion section 433, when expanded, has the same function as valve body 425 described above with reference to Fig. 4, and can prevent fluid inside the living body (e.g., cerebrospinal fluid) from leaking to the outside of the living body. As a result, according to bodily fluid circulation port 4B of this specific example, expansion section 433 prevents cerebrospinal fluid present inside subarachnoid space 55 from coming into contact with air, thereby reducing the risk of infection without creating a subcutaneous tunnel. In addition, the same effects as those of bodily fluid circulation port 4 described above with reference to Figs. 3 and 4 can be obtained. Furthermore, bodily fluid circulation port 4B of the second modified example may be provided with a communication port and a tube like those of bodily fluid circulation port 4A of the first modified example shown in Fig. 5.

[0072] FIG. 7 is a perspective view showing a bodily fluid circulating port according to a second embodiment of the present invention. FIG. 8 is a cross-sectional view taken along the cutting plane BB shown in FIG. In cases where the components of the bodily fluid circulating port 4C of this embodiment are similar to the components of the bodily fluid circulating port 4 of this embodiment described above with reference to Figures 3 and 4, duplicated explanations will be omitted as appropriate, and the following explanation will focus on the differences.

[0073] The bodily fluid communication port 4C includes a tip portion 41A, a fitting portion 42, and a base end portion 43. The fitting portion 42 and the base end portion 43 are as described above with reference to FIGS.

[0074] Tip portion 41A has a plurality of branch portions 414. In the bodily fluid circulation port 4C shown in Fig. 7, tip portion 41A has four branch portions 414. However, the number of branch portions 414 is not limited to four, and may be two, three, five or more.

[0075] The branch portion 414 has a shape that branches out and widens radially outward from the fitting portion 42. Configuring the branch portion 414 in this manner facilitates operations such as folding the tip portion 41A, thereby facilitating insertion of the tip portion 41A into a cavity containing cerebrospinal fluid. An end of the branch portion 414 has a circulation port 411A. As shown in FIG. 7 , in this specification, the term “end of the branch portion 414” refers not only to the end of the branch portion 414 extending radially outward from the fitting portion 42, but also to both ends of the branch portion 414 extending radially outward from the fitting portion 42. In the bodily fluid circulation port 4C shown in FIG. 7 , the circulation ports 411A are formed at the end of the branch portion 414 extending radially outward from the fitting portion 42 and at both ends of the branch portion 414 extending radially outward from the fitting portion 42. The other structures are the same as those of the bodily fluid passing port 4 described above with reference to FIGS.

[0076] According to the bodily fluid circulating port 4C of this embodiment, the tip portion 41A has multiple branches 414 that branch outward in the radial direction from the fitting portion 42 and spread outward, and therefore functions as an anchor after being inserted into the subarachnoid space 55. Therefore, the tip portion 41A can prevent the bodily fluid circulating port 4C from slipping out of the hole 56 when cerebrospinal fluid flows into the flow path 412 from the flow opening 411A at the end of the branch 414, or when a liquid such as a medicinal solution is injected into the accommodation cavity from outside the living body via the chamber 431. Furthermore, because the multiple branches 414 branch outward in the radial direction from the fitting portion 42 and spread outward, a medical professional can easily insert the tip portion 41A into the subarachnoid space 55 through the hole 56. Furthermore, the same effects as those of the bodily fluid circulating port 4 described above with reference to FIGS. 3 and 4 can be obtained. The bodily fluid circulating port 4C according to the second embodiment may also have a configuration similar to that of the modified examples shown in FIGS. 5 and 6. When the bodily fluid passing port 4C has the same configuration as that shown in FIGS. 5 and 6, the same effects as those described above with reference to FIGS. 5 and 6 can be obtained.

[0077] The above describes an embodiment of the present invention. However, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the claims. The configurations of the above embodiment can be partially omitted or arbitrarily combined differently from those described above. Furthermore, while the flow path 412 serves as a discharge path and the insertion portion 424 serves as an injection path in the above embodiment, these functions may be reversed. That is, liquid may be injected into a living body through the flow path 412, and the body fluid may be discharged by inserting the discharge device 32 into the insertion portion 424. [Explanation of symbols]

[0078] 2: Fluid circulation system, 2A: Fluid drainage system, 4: Body fluid circulation port, 4A: Body fluid circulation port, 4B: Body fluid circulation port, 4C: Body fluid circulation port, 21: Infusion line, 22: Drainage line, 23: Fluid delivery section, 24: Oxygenation mechanism, 25: Oxygen supply source, 26: Heat exchanger, 27: Reservoir tank, 28: Storage section, 31: Infusion device, 32: Drainage device, 32A: Needle, 32B: Tube, 41: Distal end portion, 41A: Distal end portion, 42: Fitting portion, 43: Base end portion, 43A: Base end portion, 43B: Base end portion, 51: Skull, 52: Dura mater, 53: Arachnoid mater, 54: Pia mater, 55: Subarachnoid space, 56: Hole, 271: First tube, 272: Second pipe, 273: Third pipe, 411: Flow port, 411A: Flow port, 412: Flow path, 413: Flare portion, 414: Branch portion, 421: Outer wall, 422: Inner wall, 423: Internal space, 424: Insertion portion, 425: Valve body, 431: Chamber, 432: Communication port, 433: Expansion portion

Claims

1. A bodily fluid circulating port that is used by fitting into a hole formed on the surface of a living body, a tip portion that is inserted through the hole into the cavity in which the body fluid is accommodated, the tip portion having a flow port through which the body fluid flows and a flow path that communicates with the flow port and through which the body fluid flows; a fitting portion that fits into the hole, has an internal space that is partitioned by a cylindrical outer wall and a cylindrical inner wall and is connected to the flow path, and has an insertion portion on the inside of the inner wall for passing a medical device into the skull; a proximal end portion disposed outside the living body and having a chamber connected to the internal space for receiving the bodily fluid; A bodily fluid circulation port comprising:

2. 2. The bodily fluid port according to claim 1, wherein the base end further has a communication port connected to the chamber and communicating with the outside of the chamber.

3. the flow path is a first flow path, 2. The bodily fluid circulating port according to claim 1, wherein the internal space is a second flow path for communicating with the outside of the living body.

4. 2. The bodily fluid circulating port according to claim 1, wherein the base end is made of a flexible material and is deformable in response to fluctuations in intravital pressure caused by the bodily fluid.

5. the tip end portion has a flare portion that has a flare shape that widens radially outward from the fitting portion, 2. The bodily fluid port according to claim 1, wherein the end of the flared portion has the flow port.

6. the tip portion has a plurality of branched portions that branch out and expand radially outward from the fitting portion, 2. The bodily fluid port according to claim 1, wherein the end of the branched portion has the flow port.

7. 2. The bodily fluid port according to claim 1, wherein the fitting portion has a valve body provided in the insertion portion to prevent fluid inside the living body from leaking to the outside of the living body.

8. 2. The bodily fluid passage port according to claim 1, wherein the hole is formed by trepanning the head, and the bodily fluid is cerebrospinal fluid.

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