Catheter device and retrieval method

Abstract

To provide a catheter device and retrieval method that can reduce the burden on blood vessels. [Solution] The catheter device according to this disclosure is characterized by comprising a peeling mechanism 4 that peels the intima 21 to which the lesion 20 is attached from the media 22 by supplying liquid between the intima 21 and the media 22 of the blood vessel 2 through a crack (first crack 25) formed in the intima 21 of the blood vessel 2. The intima 21 is easily peeled from the media 22 by the pressure of the liquid that flows between the intima 21 and the media 22. Therefore, it is not necessary to bring the peeling mechanism 4 or other instrument into contact with the blood vessel 2 in order to peel the intima 21. Moreover, it is possible to prevent the inconvenience of removing the media 22 when removing the intima 21. As a result, the burden on the blood vessel 2 can be reduced.

Description

Technical Field

[0001] The present disclosure relates to a catheter device and a retrieval method.

Background Art

[0002] Conventionally, for the purpose of removing lesions (plaques, thrombi, etc.) attached to the intima of a patient's blood vessel, particularly the carotid artery, or treating vascular occlusion, surgical carotid endarterectomy (CEA) and percutaneous stent placement using a catheter have been performed. A blood vessel has a three-layer structure of intima, media, and adventitia. A catheter device may include a peeling mechanism. The user inserts the peeling mechanism between the media and the intima of the blood vessel through a crack formed in the intima of the blood vessel. Next, the user advances the peeling mechanism along the blood vessel. As a result, the intima to which the lesion adheres is peeled off from the media by the peeling mechanism.

[0003] By peeling the intima, the lesion can be reliably removed together with the intima. Therefore, for example, inconveniences such as unstable plaques rupturing to form thrombi and being washed away to the peripheral blood vessels to clog the peripheral blood vessels can be prevented. In addition, a wide vascular lumen can be secured. Moreover, since the lesion can be removed by performing minimally invasive surgery using a catheter device, the burden on the human body is smaller than in the case of performing highly invasive surgery such as incising the blood vessel to remove the lesion. This type of catheter device is disclosed, for example, in Patent Document 1.

Prior Art Documents

Patent Documents

[0004] <000]023>

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The less burden on the human body, the better. However, in the case of the catheter device described in Patent Document 1, contact between the dissection mechanism and the blood vessel is essential during intimal dissection, making it difficult to further reduce the burden on the blood vessel.

[0006] The purpose of this disclosure is to provide a catheter device and retrieval method that can reduce the burden on blood vessels. [Means for solving the problem]

[0007] (1) The catheter device according to the present disclosure is characterized by comprising a peeling mechanism that peels the intima to which a lesion is attached from the media by supplying fluid between the intima and the media of the blood vessel through a crack formed in the intima of the blood vessel.

[0008] (2) The catheter device described in (1) above, wherein the dissection mechanism comprises a supply tube inserted into the blood vessel and for supplying the fluid toward the terminal side, and a nozzle for supplying the fluid supplied through the supply tube between the intima and media through the crack.

[0009] (3) The catheter device described in (2) above is characterized in that the peeling mechanism comprises a plurality of nozzles.

[0010] (4) The catheter device described in (2) or (3) above, wherein the nozzle is rotatable in the circumferential direction of the blood vessel when inserted into the blood vessel.

[0011] (5) The catheter device according to any one of (2) to (4) above, wherein the nozzle is bent, the proximal portion extends diagonally from the supply tube toward the insertion direction, and the tip portion is aligned toward the insertion direction.

[0012] (6) The catheter device described in (1) above, wherein the dissection mechanism comprises a balloon that expands into a cylindrical shape when the liquid is supplied, and a nozzle provided on the peripheral edge of the end face of the expanded balloon for supplying the liquid supplied to the balloon between the inner membrane and the middle membrane through the crack.

[0013] (7) The catheter device described in (1) above, wherein the peeling mechanism comprises a balloon that expands when the liquid is supplied, a crack-forming portion provided on the outer surface of the expanded balloon which forms the crack when the balloon expands, and a plurality of nozzles provided on the outer surface for supplying the liquid supplied to the balloon between the inner membrane and the middle membrane through the crack.

[0014] (8) A catheter device according to any one of (1) to (6) above, further comprising a balloon that expands to form the crack.

[0015] (9) The catheter device described in (8) above, wherein the balloon is expandable and expands proximal to the lesion to form the crack, contracts after the crack is formed, expands again distal to the lesion, and the dissection mechanism supplies the fluid between the intima and media through the crack when the balloon is expanded again distally.

[0016] (10) The catheter device described in (3) above further comprises a tubular sheath capable of housing a plurality of nozzles in its lumen, wherein when the sheath moves proximal, the plurality of nozzles protrude relatively from the sheath so as to move away from each other, and when the sheath moves distal, the plurality of nozzles retract relatively into the sheath so as to move closer to each other, and the plurality of nozzles that are approaching each other are capable of gripping the detached inner lining.

[0017] (11) The catheter device according to any one of (1) to (9) above, further comprising a recovery mechanism for recovering the peeled inner membrane.

[0018] (12) The catheter device according to any one of (1) to (11) above, wherein the hydraulic pressure of the liquid supplied to the peeling mechanism is 10 mmHg or more and 600 mmHg or less.

[0019] (13) The recovery method according to the present disclosure forms a crack in the inner membrane of a blood vessel, supplies a liquid between the inner membrane and the middle membrane of the blood vessel through the formed crack, peels the inner membrane from the middle membrane, and recovers the peeled inner membrane.

Effect of the Invention

[0020] According to the catheter device and the recovery method of the present disclosure, the burden on the blood vessel can be reduced.

Brief Description of the Drawings

[0021] [Figure 1] It is a diagram showing a configuration example of a catheter device according to Embodiment 1. [Figure 2] It is a diagram showing a catheter device in a state inserted into a blood vessel. [Figure 3] It is a diagram showing a catheter device arranged near a lesion. [Figure 4] It is a diagram for explaining a procedure for forming a first crack. [Figure 5] It is a diagram for explaining a procedure for peeling the inner membrane. [Figure 6] It is a diagram for explaining a procedure for recovering the inner membrane. [Figure 7] It is a diagram showing a configuration example of a catheter device according to Embodiment 2. [Figure 8] It is a cross-sectional view taken along line VIII-VIII in FIG. 7. [Figure 9] It is a diagram showing a configuration example of a catheter device according to Embodiment 3. [Figure 10] This is a cross-sectional view of the peeling mechanism. [Figure 11] This figure shows an example configuration of a catheter device according to Embodiment 4. [Modes for carrying out the invention]

[0022] Hereinafter, specific examples of catheter devices according to embodiments of this disclosure will be described with reference to the drawings. For illustrative purposes, the dimensional ratios in the drawings may differ from the actual ratios, and parts may be exaggerated or omitted.

[0023] Embodiment 1. Figure 1 shows an example of the configuration of a catheter device according to Embodiment 1. In the figure, 1 represents a catheter device. Catheter device 1 is a medical device that is inserted into the patient's blood vessel 2 to remove the lesion 20 (see Figure 3, described later) located in the lumen of blood vessel 2 and retrieve it outside the body. Blood vessel 2 is, for example, a coronary artery or a carotid artery, but is not limited to these. The lesion 20 is a plaque, thrombus, calcified lesion, etc.

[0024] Figure 2 shows the catheter device 1 inserted into blood vessel 2. Figure 3 shows a catheter device 1 positioned near the lesion 20. As shown in Figures 2 and 3, the blood vessel 2 has a three-layer structure consisting of the intima 21, media 22, and adventitia 23. An internal elastic lamina 24 is interposed between the intima 21 and the media 22. The internal elastic lamina 24 has greater mechanical strength than the intima 21. As shown in Figure 3, lesions 20 may adhere to the intima 21.

[0025] Traditionally, there is a surgical technique to remove only the intima 21 (endarterectomy). It is also known that dissection occurs when a tear occurs in the intima 21 or media 22 of a blood vessel 2 and blood flows into the tear (e.g., spontaneous coronary artery dissection, aortic dissection). In other words, the intima 21 is easily separated from the media 22 by fluid pressure. The catheter device 1 uses a liquid to separate the intima 21 to which the lesion 20 is attached from the media 22 in order to reduce the burden on the blood vessel 2.

[0026] As shown in Figure 1, the catheter device 1 comprises a guiding catheter 11 and a guidewire 12. The guiding catheter 11 comprises a sheath 111 and a hub 112. The sheath 111 is tubular and flexible. The outer diameter of the sheath 111 is smaller than the inner diameter of the blood vessel 2. The hub 112 is tubular and extends coaxially outward from one end of the sheath 111 in the axial direction. The outer diameter of the hub 112 is greater than or equal to the outer diameter of the sheath 111. The inner diameter of the hub 112 is greater than or equal to the inner diameter of the sheath 111. The lumen of the sheath 111 and the lumen of the hub 112 are continuous with each other.

[0027] In the following, one end of the sheath 111 (the hub 112 side) will be referred to as the base end, and the other end of the sheath 111 (the side opposite the hub 112 side) will be referred to as the end end. In the description of the embodiments, the base end refers to a certain range including the very base end and its surroundings. Similarly, the end end (tip end) refers to a certain range including the very end (front end) and its surroundings. The sheath 111 is inserted percutaneously into the blood vessel 2 so that its end approaches the lesion 20 from the upstream side of the blood flow. The portion of the sheath 111 inserted into the blood vessel 2 extends along the blood vessel 2. The hub 112 is positioned outside the body.

[0028] The constituent materials of the guiding catheter 11 include resin materials, metal materials, or combinations thereof. The resin material is preferably a soft resin material. Examples of resin materials include polyolefins, polystyrene, polyamides, polyesters, polyurethanes, polyimides, polyetheretherketones (PEEK), fluorinated polymers, or mixtures thereof. Examples of polyolefins include polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ionomers, or mixtures of two or more of these. Examples of fluorinated polymers include polytetrafluoroethylene (PTFE) and ethylene-tetrafluoroethylene copolymer (ETFE). Examples of metal materials include stainless steel, titanium, and titanium alloys.

[0029] The guidewire 12 is a longer wire than the guiding catheter 11 and is flexible. The outer diameter of the guidewire 12 is smaller than the inner diameter of the sheath 111. The materials used to construct the guidewire 12 include hard resin and metal (e.g., stainless steel, titanium, nickel-titanium alloy).

[0030] The catheter device 1 further comprises a crack formation mechanism 3 and a dissection mechanism 4. The detachment mechanism 4 is used to detach the intima 21 to which the lesion 20 is attached from the media 22. The crack formation mechanism 3 is used to form a first crack 25 and a second crack 26 in order to detach the intima 21 to which the lesion 20 is attached (see Figure 3 and Figures 4 and 5 described later). The first crack 25 (crack) is formed in the intima 21 proximal to the lesion 20 (upstream of blood flow). The second crack 26 is formed in the intima 21 distal to the lesion 20 (downstream of blood flow). The crack formation mechanism 3 and the peeling mechanism 4 are attached to the guide wire 12.

[0031] The guidewire 12, to which the crack-forming mechanism 3 and the peeling mechanism 4 are attached, is inserted into the guiding catheter 11 from the proximal end to the distal end after the guiding catheter 11 has been inserted into the blood vessel 2 (see Figure 1). The guidewire 12 is guided by the guiding catheter 11 and inserted into the blood vessel 2 along the blood vessel 2. The guidewire 12 penetrates the lumen of the guiding catheter 11 so as to be movable relative to the guiding catheter 11 in the axial direction. As a result, the guidewire 12 extends in the longitudinal direction of the guiding catheter 11. The distal end of the guidewire 12 protrudes outward through the distal opening of the sheath 111 and is positioned in the lumen of the blood vessel 2. The proximal end of the guidewire 12 protrudes outward through the proximal opening of the hub 112.

[0032] The crack formation mechanism 3 is a so-called balloon catheter, and as shown in Figures 1 to 3, it comprises a catheter 31, a water supply pipe 32, and a balloon 33. The catheter 31 is tubular and flexible. The outer diameter of the catheter 31 is smaller than the inner diameter of the sheath 111. The inner diameter of the catheter 31 is larger than the outer diameter of the guidewire 12. The water supply pipe 32 is tubular and flexible. The outer diameter of the water supply pipe 32 is smaller than the inner diameter of the catheter 31. A balloon 33 is connected to one end of the water supply pipe 32. The other end of the water supply pipe 32 is connected to a water supply and drainage device 51. The water supply and drainage device 51 may be a balloon inflator.

[0033] The balloon 33 is expandable and contractible. The balloon 33 expands when the water supply and drainage device 51 supplies physiological saline to the balloon 33 through the water supply pipe 32. The fluid supplied to the balloon 33 is not limited to physiological saline, but may also be other liquids (contrast agents, blood, etc.) or gases (helium, oxygen, carbon dioxide, etc.). The water supply and drainage device 51 discharges saline solution from the balloon 33 through the water supply pipe 32, causing the balloon 33 to deflate. Alternatively, the saline solution may be discharged into the lumen of the blood vessel 2.

[0034] In its expanded state, the balloon 33 is cylindrical with a thick circumferential wall. The inner diameter of the balloon 33 is larger than the outer diameter of the guidewire 12. The balloon 33 can be expanded until its outer diameter is equal to the inner diameter of the blood vessel 2. That is, the outer surface of the expanded balloon 33 can contact the inner surface of the intima 21. The outer diameter of the deflated balloon 33 is smaller than the inner diameter of the sheath 111. Since the outer surface of the expanded balloon 33 is cylindrical, the burden on the blood vessel 2 is limited even if it comes into contact with it. The outer surface of the expanded balloon 33 is not limited to a cylindrical shape; any shape that minimizes the burden on the blood vessel 2, such as a spherical shape, is also acceptable. Note that the balloon 33 is not limited to a cylindrical configuration.

[0035] The balloon 33 is arranged coaxially with the catheter 31, and one end of the balloon 33 in the axial direction is connected to one end of the catheter 31. The water supply pipe 32 is routed along the catheter 31 by penetrating its lumen. Alternatively, the water supply pipe 32 may be routed on the outside of the catheter 31. The constituent materials of the crack formation mechanism 3 are, for example, the same as the constituent materials of the guiding catheter 11.

[0036] The crack-forming mechanism 3 is attached to the guidewire 12 by the guidewire 12 penetrating the lumen of the catheter 31 and the balloon 33. As a method of attaching the guidewire 12 to the catheter 31 and balloon 33, the catheter 31 and balloon 33 may be provided with a guidewire lumen through which the guidewire 12 can pass. In the attached crack-forming mechanism 3, the balloon 33 is located at the end of the crack-forming mechanism 3. When the user manipulates the catheter 31, the crack-forming mechanism 3 is guided and moved by the guidewire 12. The crack-forming mechanism 3 is inserted into the guiding catheter 11 from the proximal end towards the distal end while attached to the guidewire 12. As a result, the water supply tube 32 is inserted into the blood vessel 2 so as to follow the blood vessel 2. The distal ends of the catheter 31 and the water supply tube 32 protrude outward from the hub 112. Physiological saline is supplied to the distal end through the water supply tube 32.

[0037] The balloon 33 is provided with a crack-forming portion 34. The crack-forming portion 34 is a convex ridge with a triangular cross-section and protrudes outward from the outer surface of the expanded balloon 33. The length of the crack-forming portion 34 protruding from the outer surface of the balloon 33 is approximately 0.1 mm to 0.5 mm, which is about the same as the thickness of the intima 21 (if the blood vessel 2 is a carotid artery, the thickness of the intima-media (IMT) is approximately 0.4 to 1.0 mm). The crack-forming portion 34 extends around the entire circumference of the balloon 33.

[0038] The inner surface of the inflated balloon 33 comes into contact with the inner surface of the intima 21, and the crack-forming portion 34 comes into contact with and bites into the intima 21, thereby forming a first crack 25 (or a second crack 26) in the intima 21. The formation of the first crack 25 causes the internal elastic lamina 24 to be partially exposed to the lumen of the blood vessel 2. Since the crack-forming portion 34 extends around the entire circumference of the balloon 33, the first crack 25 extends around the entire circumference of the blood vessel 2. The structure of the second crack 26 is the same as that of the first crack 25. The balloon 33 is provided with a marker 35 that indicates the location of the crack formation portion 34. The marker 35 contains, for example, a metal that shields against X-rays.

[0039] In this embodiment, the crack-forming portion 34 is integrally provided with the balloon 33, but is not limited to this, and may be a separate component (for example, a wire wrapped around the balloon 33). The crack-forming portion 34 is not limited to a continuous ridge extending around the entire circumference of the balloon 33, but may be an intermittent configuration in which, for example, multiple protrusions are arranged in the circumferential direction of the balloon 33. When the crack-forming portion 34 is intermittent, the balloon 33 tends to become smaller and more compact when deflated. However, in order to form a continuous first crack 25 (and second crack 26) in the circumferential direction of the blood vessel 2, it is necessary to rotate the balloon 33 around the guide wire 12. The cross-section of the crack-forming portion 34 is not limited to a triangular shape, but may be rectangular, semicircular, circular, etc.

[0040] The peeling mechanism 4 comprises a base body 41, two nozzles 42, and a supply pipe 43. The base 41 has a thick peripheral wall and is cylindrical in shape, shorter than the sheath 111. The outer diameter of the base 41 is smaller than the inner diameter of the sheath 111. The inner diameter of the base 41 is larger than the outer diameter of the catheter 31.

[0041] Each nozzle 42 extends outward from the outer circumferential surface of the base body 41. The nozzle 42 is bent and has a base portion 421 in the direction of extension and a tip portion 422 in the direction of extension. As described later, the base 41 is positioned so that its axial length aligns with the blood vessel 2. The extension direction of the proximal portion 421 from the base 41 is inclined with respect to the insertion direction toward the distal side and toward the side approaching the blood vessel 2. The extension direction of the tip portion 422 from the proximal portion 421 is aligned with the insertion direction. The two nozzles 42 are equally spaced in the circumferential direction of the base body 41. The distance between the tip portions 422 of the two nozzles 42 (length in the direction perpendicular to the axial direction of the base body 41) is greater than the outer diameter of the sheath 111.

[0042] However, each nozzle 42 is flexible, and the two nozzles 42 are configured to move toward and away from each other. When the two nozzles 42 are relatively immersed in the sheath 111, the two nozzles 42 move toward each other by bending. The two nozzles 42 that are close together can be housed in the sheath 111. Also, the two nozzles 42 that are close together can hold the detached inner film 21 between them. When the two nozzles 42 that were housed in the sheath 111 protrude outward from the end opening of the sheath 111, the two nozzles 42 separate from each other due to their respective elastic forces (restoring forces).

[0043] The constituent materials of the detachment mechanism 4 are, for example, the same as the constituent materials of the guiding catheter 11. It is desirable that at least the nozzle 42 (especially the tip portion 422) is configured to deform flexibly when in contact with other members (e.g., the sheath 111) or the blood vessel 2, and to quickly return to its original shape when separated from the other members or the blood vessel 2. The base portion 421 of each nozzle 42 is connected to one end of the supply pipe 43. The other end of the supply pipe 43 is connected to a liquid supply device 52. The liquid supply device 52 supplies liquid to the nozzles 42 through the supply pipe 43, causing the liquid to be ejected from the tip portion 422 of the nozzle 42 in the extending direction.

[0044] The liquid supplied to the dissection mechanism 4 is physiological saline. However, it is not limited to physiological saline; contrast agents, blood, etc., may also be supplied to the dissection mechanism 4. The fluid pressure supplied to the separation mechanism 4 is between 10 mmHg and 600 mmHg. The lower limit of the fluid pressure is not limited to 10 mmHg; for example, it may be 60 mmHg, the patient's diastolic blood pressure, or 300 mmHg. The upper limit of the fluid pressure is not limited to 600 mmHg; for example, it may be 100 mmHg, or the patient's systolic blood pressure.

[0045] Since the intima 21 is easily peeled off, it can be peeled off if the fluid pressure is 10 mmHg or higher. If the fluid pressure is within the range of the patient's diastolic to systolic blood pressure, it is possible to efficiently peel off the intima 21 while reducing the burden on the blood vessel 2. If the fluid pressure is 300 mmHg or higher, the intima 21 can be peeled off even more efficiently, and the time required for the peeling procedure can be shortened, thereby reducing the burden on the patient. The internal elastic plate 24 can withstand a blood pressure of 600 mmHg, so if the fluid pressure is 600 mmHg or less, the internal elastic plate 24 can protect the media 22 and adventitia 23 from the liquid ejected from the nozzle 42. If the fluid pressure is 100 mmHg or less, the burden on the blood vessel 2 can be minimized.

[0046] It is desirable that the liquid supply device 52 be configured to increase or decrease the liquid pressure according to the user's operation. In this case, for example, by adjusting the liquid pressure while the liquid is being ejected from the nozzle 42, it is possible to flexibly choose whether to achieve both efficient removal of the intima 21 and reduction of the burden on the blood vessel 2, or to prioritize one or the other.

[0047] The attachment of the peeling mechanism 4 to the guidewire 12 is performed after the attachment of the crack formation mechanism 3 to the guidewire 12. The peeling mechanism 4 is attached to the guidewire 12 via the catheter 31 by the catheter 31 penetrating the lumen of the base 41. At this time, the circumferential direction of the base 41 is aligned with the circumferential direction of the guidewire 12. The supply tube 43 is positioned along the guidewire 12.

[0048] The dissection mechanism 4 is inserted into the guiding catheter 11 from the proximal end towards the distal end while attached to the guidewire 12. As a result, the supply tube 43 is inserted into the blood vessel 2 so as to follow the blood vessel 2. The fluid is supplied through the supply tube 43 toward the distal end. The proximal end of the supply tube 43 protrudes outward from the hub 112. The fluid supplied by the fluid supply device 52 is ejected from the nozzle 42 toward the distal end.

[0049] The base 41 is movable, guided by the guide wire 12. For example, the base 41 moves when the user operates the supply pipe 43. As the base 41 moves, the two nozzles 42 move along the guide wire 12. When the base 41 is outside the sheath 111, the base 41 is circumferentially rotatable around the guide wire 12. For example, the base 41 rotates when the user applies an external force to the supply pipe 43. As the base 41 rotates, the two nozzles 42 rotate around the guide wire 12.

[0050] The dissection mechanism 4 may further include an operating catheter, the distal end of which is connected to the base 41, and the proximal end of which protrudes outward from the hub 112. In this case, the user moves or rotates the base 41 by operating the operating catheter.

[0051] Figure 4 is a diagram illustrating the procedure for forming the first crack 25. For clarity, the outer membrane 23 and inner elastic lamina 24 of the blood vessel 2, as well as the catheter 31 and water supply tube 32 of the crack formation mechanism 3, have been omitted from the diagram. In the following, distal movement will be referred to as forward movement, and proximal movement as backward movement. The user positions the guidewire 12 along the axis of the blood vessel 2. When the guidewire 12 is along the axis of the blood vessel 2, there is no risk of the crack formation mechanism 3 or the peeling mechanism 4 coming into contact with the blood vessel 2 while moving.

[0052] As shown in Figure 4A, the user advances the deflated balloon 33 and stops it near the proximal side of the lesion 20. The user stops the balloon 33 when the marker 35 reaches the position corresponding to the planned formation location of the first crack 25. Next, the user operates the water supply and drainage device 51 to inflate the balloon 33 as shown in Figure 4B. The expansion of the balloon 33 causes the crack-forming portion 34 to bite into the intima 21, forming a first continuous crack 25 in the circumferential direction of the blood vessel 2.

[0053] After the first crack 25 is formed, the user operates the water supply and drainage device 51 to deflate the balloon 33, and as shown in Figure 4C, advances the deflated balloon 33 and stops it near the distal side of the lesion 20. The user stops the balloon 33 when the marker 35 reaches the position corresponding to the planned formation location of the second crack 26.

[0054] Figure 5 is a diagram illustrating the procedure for dissecting the intima 21. In Figure 5 and Figure 6 described later, the adventitia 23 and internal elastic lamina 24 of the blood vessel 2 are not shown. The user reinflates the balloon 33 as shown in Figure 5A. The inflation of the balloon 33 causes the crack-forming portion 34 to bite into the intima 21, forming a second continuous crack 26 in the circumferential direction of the blood vessel 2.

[0055] Furthermore, the user advances the nozzle 42 and stops it near the proximal side of the lesion 20. The stopping position of the nozzle 42 is where the tip portion 422 of the nozzle 42 is inserted into the first crack 25. Since the tip portion 422 extends along the blood vessel 2 and is easily deformable, there is no risk of the tip of the tip portion 422 coming into contact with the blood vessel 2 and putting stress on it. A marker similar to the marker 35 may be provided on the tip portion 422. The nozzle 42 may move forward and stop before or after the balloon 33 is re-expanded.

[0056] After the balloon 33 is reinflated, the user operates the liquid supply device 52 to supply liquid to the terminal end through the supply tube 43, as shown in Figure 5B. The supplied liquid is ejected from each nozzle 42 and supplied between the inner membrane 21 and the intermediate membrane 22 through the first crack 25. Due to the liquid pressure of the supplied liquid, the inner membrane 21 begins to separate from the intermediate membrane 22.

[0057] While continuing to supply the fluid, the user operates the supply tube 43 to rotate the two nozzles 42 in the circumferential direction of the guide wire 12 (i.e., in the circumferential direction of the blood vessel 2), as shown in Figure 5C. The user also operates the supply tube 43 to advance the two nozzles 42 closer to the vicinity of the balloon 33. As a result, the intima 21 between the first crack 25 and the second crack 26 (i.e., the intima 21 to which the lesion 20 is attached) can be peeled off evenly and comprehensively in the circumferential direction of the blood vessel 2 and along the blood vessel 2.

[0058] The expanded balloon 33 occludes the blood vessel 2. Therefore, it is desirable that the catheter 31 and balloon 33 be provided with a passage that allows blood to flow from the upstream side to the downstream side of the balloon 33. In this case, fluid is supplied to expand the balloon 33.

[0059] Furthermore, the supply of fluid for detaching the intima 21 may be performed before the balloon 33 is re-expanded (i.e., before the second crack 26 is formed). In this case, the second crack 26 is formed by the re-expanding of the balloon 33 after the intima 21 has been detached. The advantage of this procedure is that the time the balloon 33 occludes the blood vessel 2 is shortened, so blood flow is less likely to be obstructed. However, there is a risk of accidentally detaching the intima 21 distal to the second crack 26.

[0060] Figure 6 illustrates the procedure for retrieving the intima 21. As shown in Figure 6A, once the inner film 21 between the first crack 25 and the second crack 26 has been completely peeled off, the user stops the rotation and forward movement of the nozzle 42 and terminates the supply of liquid.

[0061] Next, as shown in Figure 6B, the user advances the sheath 111, thereby immersing the two nozzles 42 relative to the sheath 111. The two nozzles 42, immersed in the sheath 111, flex and move closer to each other. The detached inner lining 21 is placed between the two approaching nozzles 42, so that the two approaching nozzles 42 hold the detached inner lining 21 between them. Figure 6B shows the state in which the two nozzles 42 are completely immersed in the sheath 111, but parts of the two nozzles 42 may protrude outward from the sheath 111.

[0062] With the two nozzles 42 holding the detached intima 21, the user deflates the balloon 33 as shown in Figure 6C. Then, the user retracts the guiding catheter 11, guidewire 12, crack-forming mechanism 3, and detachment mechanism 4 (i.e., catheter device 1) and removes them from the blood vessel 2. As a result, the detached intima 21 is recovered from the body, ensuring that the lesion 20 is completely removed.

[0063] The user may further immerse the two nozzles 42 into the sheath 111 to accommodate the detached intima 21 in the sheath 111. In this case, the user may close the terminal opening of the sheath 111 with a balloon 33. When the terminal opening of the sheath 111 is closed with the intima 21 contained within the sheath 111, even if the lesion 20 ruptures during transport of the intima 21, the fragmented lesion 20 due to the rupture will not remain in the lumen of the blood vessel 2, and the lesion 20 can be reliably removed.

[0064] With the catheter device 1 described above, the peeling mechanism 4 or other instruments do not come into contact with the blood vessel 2 in order to peel off the intima 21, and the media 22 and adventitia 23 are protected when the intima 21 is peeled off, thus reducing the burden on the blood vessel 2. Since the peeling mechanism 4 and the sheath 111 also serve as a recovery mechanism for collecting the peeled intima 21, the catheter device 1 can be made compact. Alternatively, the peeling mechanism 4 may be equipped with a sheath different from the sheath 111, and the two nozzles 42 may be immersed in (and protrude from) this sheath, causing the two nozzles 42 to move closer to (and further apart) each other. In this case, the peeling mechanism 4 alone serves as the recovery mechanism.

[0065] The number of nozzles 42 may be three or more. Multiple nozzles 42 may be unevenly distributed. The number of nozzles 42 may be just one, but the catheter device 1 must be equipped with a separate means for collecting the detached intima 21. The catheter device 1 may further include an application mechanism for applying a drug to the blood vessel 2 from which the intima 21 has been stripped, or a placement mechanism for placing a stent. After removing the intima 21 and withdrawing the catheter device 1, the user may use another therapeutic catheter for applying the drug or placing a stent.

[0066] Embodiment 2. The configuration and usage procedure of the catheter device 1 of Embodiment 2 are substantially the same as those of the catheter device 1 of Embodiment 1, except that the configuration of the dissection mechanism 4 is different and it is equipped with a retrieval mechanism (not shown). The catheter device 1 of Embodiment 2 provides substantially the same effects and benefits as the catheter device 1 of Embodiment 1. The differences from Embodiment 1 will be described below, and other components identical to those of Embodiment 1 will be denoted by the same reference numerals and their descriptions will be omitted.

[0067] Figure 7 shows an example of the configuration of the catheter device 1 according to Embodiment 2. In the following, the outer membrane 23 and inner elastic lamina 24 of the blood vessel 2 are omitted from the illustration. The peeling mechanism 4 of this embodiment includes a balloon 44 and a plurality of nozzles 45, instead of the base 41 and two nozzles 42 of Embodiment 1. The balloon 44 is expandable and expandable, and in its expanded state, it forms a cylindrical shape with a thick circumferential wall. The inner circumferential surface of the balloon 44 is not shown. The inner diameter of the balloon 44 is larger than the outer diameter of the guidewire 12. The balloon 44 can be expanded until its outer diameter is equal to the inner diameter of the blood vessel 2. That is, the outer circumferential surface of the expanded balloon 44 can contact the inner circumferential surface of the intima 21. The outer diameter of the deflated balloon 44 is smaller than the inner diameter of the sheath 111.

[0068] Since the outer surface of the expanded balloon 44 is cylindrical, the burden on the blood vessel 2 is limited even if it comes into contact with it. The outer surface of the expanded balloon 44 is not limited to a cylindrical shape; any shape that minimizes the burden on the blood vessel 2, such as a spherical shape, is also acceptable. Note that the balloon 44 is not limited to a cylindrical configuration. The dissection mechanism 4 is attached to the guidewire 12 by the catheter 31 penetrating the lumen of the balloon 44. In the dissection mechanism 4 attached to the guidewire 12, the end of the supply tube 43 is connected to the proximal end face of the balloon 44.

[0069] Figure 8 is a cross-sectional view taken along the line VIII-VIII in Figure 7. The guide wire 12 and water supply pipe 32 are not shown. As shown in Figures 7 and 8, multiple nozzles 45 are arranged side by side on the outer peripheral edge of the end face of the balloon 44. Each nozzle 45 is a through-hole that penetrates the end face at the distal end of the balloon 44. The axial direction of the nozzle 45 is parallel to the axial direction of the balloon 44. The axial direction of the nozzle 45 may also be inclined with respect to the axial direction of the balloon 44 so that liquid is ejected from the nozzle 45 toward the blood vessel 2.

[0070] The liquid supply device 52 supplies liquid to the balloon 44 through the supply pipe 43, causing the balloon 44 to expand and liquid to be ejected from each nozzle 45. When the liquid supply device 52 stops supplying liquid and an external force is applied to cause the balloon 44 to recede relative to the sheath 111, the liquid is discharged through each nozzle 45 and the balloon 44 deflates. Alternatively, the liquid supply device 52 may discharge the liquid from the balloon 44 through the supply pipe 43.

[0071] After the formation of the first crack 25 and the second crack 26 by the crack formation mechanism 3, the user advances the balloon 44 and stops it near the proximal side of the lesion 20, then expands it. As the balloon 44 expands, the nozzle 45 comes closest to the first crack 25. Since there is no risk of the nozzle 45 coming into contact with the blood vessel 2, there is no burden on the blood vessel 2 caused by the nozzle 45.

[0072] After the balloon 44 is inflated, the user has the fluid supply device 52 supply fluid. The fluid ejected from the nozzle 45 is supplied between the intima 21 and the media 22 through the first crack 25. The fluid pressure of the supplied fluid causes the intima 21 to separate from the media 22. Since multiple nozzles 45 are arranged circumferentially around the blood vessel 2, it is not necessary to rotate the balloon 44 circumferentially around the guidewire 12. Furthermore, the user may perform the operation of forming a second crack 26 using the crack formation mechanism 3 after peeling off the inner membrane 21.

[0073] Once the intima 21 between the first crack 25 and the second crack 26 has been completely detached, the user terminates the fluid supply and removes the detachment mechanism 4 from the guiding catheter 11. Next, the user inserts a retrieval mechanism (not shown) into the guiding catheter 11 and performs the retrieval of the detached intima 21. After or in conjunction with the retrieval of the intima 21, the user retracts the catheter device 1 and removes it from the blood vessel 2.

[0074] Alternatively, instead of inserting a recovery mechanism, the catheter device 1 may be configured to connect an aspiration device (not shown) to the guiding catheter 11 and aspirate the detached intima 21 through the guiding catheter 11. The nozzle 45 may be cylindrical in shape, protruding outward from the distal end face of the balloon 44. However, it is desirable that the tip position of the nozzle 45 in the protruding direction be inside the outer surface of the balloon 44 (so that the nozzle 45 does not come into contact with the blood vessel 2 when the outer surface of the balloon 44 comes into contact with the inner surface of the blood vessel 2).

[0075] Embodiment 3. The configuration and usage procedure of the catheter device 1 of Embodiment 3 are substantially the same as those of the catheter device 1 of Embodiment 1, except for the following two points: First, the configuration of the peeling mechanism 4 is different; second, the crack formation mechanism 3 does not form the first crack 25. The catheter device 1 of Embodiment 3 provides substantially the same effects as the catheter device 1 of Embodiment 2. The differences from Embodiment 1 will be explained below, and other components identical to those of Embodiment 1 will be denoted by the same reference numerals and their descriptions will be omitted.

[0076] Figure 9 shows an example of the configuration of the catheter device 1 according to Embodiment 3. The peeling mechanism 4 of this embodiment further comprises a crack-forming portion 46. Figure 10 is a cross-sectional view of the release mechanism 4. The inner surface of the balloon 44 is not shown. As shown in Figures 9 and 10, the crack-forming portion 46 is provided on the balloon 44. The crack-forming portion 46 is a convex ridge with a triangular cross-section and protrudes outward from the outer surface (external surface) of the balloon 44. The length of the crack-forming portion 46 protruding from the outer surface of the balloon 44 is approximately the same as the thickness of the inner membrane 21. The crack-forming portion 46 extends around the entire circumference of the balloon 44. The balloon 44 may be provided with markers to indicate the position of the crack-forming portion 46.

[0077] The inner surface of the inflated balloon 44 comes into contact with the inner surface of the inner membrane 21, and the crack-forming portion 46 comes into contact with and bites into the inner membrane 21, thereby forming a first crack 25 in the inner membrane 21. The first crack 25 formed by the crack-forming portion 46 is the same as the first crack 25 formed by the crack-forming portion 34 in Embodiment 1. In Embodiment 2, each nozzle 45 is provided on the end face of the balloon 44, whereas in this embodiment, each nozzle 45 is provided in the crack-forming portion 46. Each nozzle 45 is a through-hole that penetrates one end surface of the crack-forming portion 46 (a part of the outer surface of the balloon 44).

[0078] Before forming the first crack 25, the user performs the operation of forming a second crack 26 using the crack formation mechanism 3. After the formation of the second crack 26, the user advances the balloon 44 and stops it near the proximal side of the lesion 20, and supplies liquid to the liquid supply device 52. As the balloon 44 expands, the crack-forming portion 46 bites into the inner lining 21, forming the first crack 25.

[0079] Simultaneously with the expansion of the balloon 44, liquid is ejected from the nozzle 45. The liquid ejected from the nozzle 45 is supplied between the intima 21 and the media 22 through the first crack 25. The fluid pressure of the supplied liquid causes the intima 21 to separate from the media 22. Since multiple nozzles 45 are arranged circumferentially around the blood vessel 2, it is not necessary to rotate the balloon 44 circumferentially around the guidewire 12. Furthermore, the user may perform the operation of forming a second crack 26 using the crack formation mechanism 3 after peeling off the inner membrane 21.

[0080] Once the intima 21 between the first crack 25 and the second crack 26 has been completely detached, the user terminates the fluid supply and withdraws the detachment mechanism 4 from the guiding catheter 11. Next, the user retrieves the detached intima 21. After or in conjunction with the retrieval of the intima 21, the user retracts the catheter device 1 and withdraws it from the blood vessel 2. In this embodiment, the nozzle 45 may be provided, for example, on the outer surface (end face or outer peripheral surface) of the balloon 44, excluding the crack-forming portion 46. However, if the nozzle 45 is provided on the crack-forming portion 46, it is easy to position the nozzle outlet of the nozzle 45 within the internal space of the first crack 25.

[0081] The liquid pressure at the time of the formation of the first crack 25 (the liquid pressure required to expand the balloon 44 and cause the crack-forming portion 46 to bite into the inner film 21) may be lower than the liquid pressure at which the inner film 21 is peeled off by the ejection of liquid from the nozzle 45. If the catheter device 1 does not have a crack-forming mechanism 3, the crack-forming portion 46 may form the first crack 25 and the second crack 26, respectively. The delamination of the intima 21 from the media 22 may be performed after the formation of the first crack 25 and the second crack 26, or after the formation of the first crack 25 and before the formation of the second crack 26. Alternatively, the catheter device 1 may not include the crack-forming mechanism 3, and the nozzle 45 may be provided on the proximal end face of the balloon 44. In this case, the crack-forming portion 46 forms a first crack 25 and a second crack 26 in that order, and then the liquid ejected from the nozzle 45 toward the proximal end is supplied between the intima 21 and the median 22 through the second crack 26.

[0082] Embodiment 4. The configuration and usage procedure of the catheter device 1 of Embodiment 4 are substantially the same as those of the catheter device 1 of Embodiment 1, except that the configuration of the dissection mechanism 4 is different. The catheter device 1 of Embodiment 4 provides substantially the same effects and benefits as the catheter device 1 of Embodiment 1. The differences from Embodiment 1 will be described below, and other components identical to those of Embodiment 1 will be denoted by the same reference numerals and their descriptions will be omitted.

[0083] Figure 11 shows an example of the configuration of the catheter device 1 according to Embodiment 4. The peeling mechanism 4 of this embodiment includes multiple recovery members 47 and multiple nozzles 48, instead of the base body 41 and two nozzles 42 of Embodiment 1. For clarity of the diagram, Figure 11 shows one nozzle 48 and one recovery member 47.

[0084] Each retrieval member 47 is a loop-shaped wire and is provided on the guide wire 12. Multiple (for example, three) retrieval members 47 move closer to each other as they are immersed in the sheath 111. As the multiple retrieval members 47 that have been immersed in the sheath 111 protrude from the sheath 111, they move apart from each other due to elastic force (restoring force). At this time, the multiple retrieval members 47 are aligned in the circumferential direction of the sheath 111 and spread out in the radial direction of the sheath 111. The retrieval members 47 may have a configuration similar to the loop-shaped wires found in so-called snare catheters.

[0085] Each nozzle 48 is tubular in shape and extends from the end of the supply pipe 43. The number of nozzles 48 is equal to the number of recovery members 47. There is a one-to-one correspondence between the recovery members 47 and the nozzles 48, and the tip portion in the extension direction of the nozzle 48 is attached to the end of the recovery member 47 when it is protruding from the sheath 111. As the recovery member 47 is immersed in (and protrudes from) the sheath 111, the nozzles 48 are immersed in (and protrude from) the sheath 111. As the recovery member 47 protrudes from the sheath 111, the tip portions in the extension direction of the multiple nozzles 48 are aligned in the circumferential direction of the sheath 111 near the inner film 21. As the recovery member 47 is immersed in the sheath 111, the multiple recovery members 47 and nozzles 48, which are approaching each other, are able to grasp the detached inner film 21.

[0086] After the formation of the first crack 25, liquid sprayed from the nozzle 48 is supplied through the first crack 25 between the inner film 21 and the intermediate film 22. The detached inner film 21 is collected by being held between multiple recovery members 47 and the nozzle 48. Since the retrieval mechanism is integrated into the dissection mechanism 4, the catheter device 1 can be made compact.

[0087] [Summary of Embodiments in this Disclosure] (1) In this disclosure, the blood vessel 2 has an intima 21 and a media 22. The detangulation mechanism 4 detangles the intima 21 to which the lesion 20 is attached from the media 22. To this end, the detangulation mechanism 4 supplies fluid between the intima 21 and the media 22 through a first crack 25 formed in the intima 21. The intima 21 easily separates from the media 22 due to the pressure of the fluid that flows between the intima 21 and the media 22. Therefore, it is not essential to bring the separation mechanism 4 or other instrument into contact with the blood vessel 2 in order to separate the intima 21. Moreover, it is possible to prevent the inconvenience of removing the media 22 when removing the intima 21. As a result, the burden on the blood vessel 2 can be reduced.

[0088] Furthermore, since there is no risk of the peeling mechanism 4 or other instruments coming into contact with the lesion 20 during the peeling of the intima 21, there is no risk of the lesion 20 being damaged and fragmented due to contact with the peeling mechanism 4 or other instruments, which would hinder the reliable removal of the lesion 20. Blood vessel 2 may be a biological blood vessel contained in the patient's body, or it may be a simulated blood vessel contained in a human body model or a 3D human body model in a virtual space.

[0089] (2) In this disclosure, the peeling mechanism 4 comprises a supply pipe 43 and a nozzle 42. In the following, the end of catheter device 1 that is inserted into the body will be referred to as the terminal end. The supply tube 43 is inserted into the blood vessel 2 and is used to supply fluid toward the distal end. The fluid flows through the supply tube 43 toward the distal end. The nozzle 42 is for supplying the liquid supplied through the supply pipe 43 between the inner membrane 21 and the intermediate membrane 22 through the first crack 25 formed in the inner membrane 21. The liquid that has passed through the supply pipe 43 is ejected from the nozzle 42 and supplied between the inner membrane 21 and the intermediate membrane 22 through the crack 25. The peeling mechanism 4 described above has a simple structure.

[0090] (3) In this disclosure, the peeling mechanism 4 is equipped with a plurality of nozzles 42, which can promote the peeling of the inner film 21. For example, a guidewire 12 is inserted into the blood vessel 2 so as to follow the vessel 2, a supply tube 43 is arranged along the guidewire 12, and a plurality of nozzles 42 are arranged in parallel in the circumferential direction of the supply tube 43. In this case, fluid ejected from each nozzle 42 can be easily supplied between the intima 21 and the media 22 through the first crack 25 which is formed continuously or intermittently in the circumferential direction of the blood vessel 2. Therefore, the peeling of the intima 21 over the entire circumference of the blood vessel 2 can be easily promoted.

[0091] (4) In this disclosure, the nozzle 42 inserted into the blood vessel 2 is rotatable in the circumferential direction of the blood vessel 2, so that the peeling of the intima 21 can be promoted. For example, a guidewire 12 is inserted into the blood vessel 2 so as to follow the vessel, and the supply tube 43 is positioned along the guidewire 12. The first crack 25 is formed continuously in the intima 21 in the circumferential direction of the blood vessel 2.

[0092] The nozzle 42 is rotatable around the guidewire 12. Typically, the guidewire 12 is inserted into the blood vessel 2 such that its axis is located at or near the axis of the blood vessel 2, so the rotational direction of the nozzle 42 is circumferential to the blood vessel 2. Therefore, the fluid ejected from the nozzle 42, which rotates circumferentially to the blood vessel 2, can be easily supplied between the intima 21 and the media 22 through the first crack 25 that is continuously formed circumferentially to the blood vessel 2. Thus, the peeling of the intima 21 over the entire circumference of the blood vessel 2 can be easily promoted.

[0093] (5) In this disclosure, the nozzle 42 comprises a base portion 421 and a tip portion 422. The proximal portion 421 extends diagonally from the supply tube 43 in the direction of insertion of the supply tube 43. The tip portion 422 extends from the tip of the proximal portion 421 in the direction of extension along the direction of insertion of the supply tube 43. That is, the nozzle 42 is bent at the boundary between the proximal portion 421 and the tip portion 422. The supply tube 43 is inserted into the blood vessel 2 and follows the blood vessel 2. Therefore, the bending angle of the nozzle 42 is the angle at which the tip portion 422 follows the direction of insertion of the supply tube 43.

[0094] The fluid ejected from the tip of the tip portion 422 in the direction of extension is supplied between the intima 21 and the media 22 through the first crack 25 formed in the intima 21. For this purpose, at least the tip of the tip portion 422 needs to be close to the first crack 25. Since the tip portion 422 follows the blood vessel 2, contact between the tip of the tip portion 422 and the blood vessel 2, thereby preventing stress on the blood vessel 2, is suppressed.

[0095] (6) In this disclosure, the peeling mechanism 4 comprises a balloon 44 and a nozzle 45. For example, the dissection mechanism 4 is inserted into the blood vessel 2 and further includes a supply tube 43 for supplying fluid toward the distal end. The fluid flows through the supply tube 43 toward the distal end. The balloon 44 expands into a cylindrical shape with its axial length aligned with the blood vessel 2 as the fluid is supplied through the supply tube 43. The nozzle 45 is located on the periphery of the end face of the expanded balloon 44. The liquid supplied to the balloon 44 is ejected from the nozzle 45 and supplied between the inner membrane 21 and the middle membrane 22 through the first crack 25 formed in the inner membrane 21.

[0096] The dissection mechanism 4 described above has a simple structure. Furthermore, by bringing the circumferential surface of the expanded balloon 44 closer to the intima 21, the nozzle 45 provided on the periphery of the end face of the balloon 44 can be brought closer to the first crack 25, thereby suppressing the convex nozzle from contacting the blood vessel 2 and putting stress on the blood vessel 2.

[0097] (7) In this disclosure, the peeling mechanism 4 comprises a balloon 44, a crack forming portion 46, and a nozzle 45. For example, the dissection mechanism 4 is inserted into the blood vessel 2 and further includes a supply tube 43 for supplying fluid toward the distal end. The fluid flows through the supply tube 43 toward the distal end. The balloon 44 expands as the fluid is supplied through the supply tube 43. The crack-forming portion 46 forms a first crack 25 by contacting the intima 21 of the blood vessel 2. The crack-forming portion 46 is provided on the outer surface of the expanded balloon 44, for example, so as to protrude outward. By expanding the balloon 44, the crack-forming portion 46 can be easily brought into contact with the intima 21. Therefore, the formation of the first crack 25 at a desired location is facilitated.

[0098] For example, the balloon 44 is expandable and contracts as the supplied liquid is expelled. By contracting the balloon 44, the crack-forming portion 46 can be easily separated from the inner membrane 21.

[0099] The nozzle 45 is provided on the outer surface of the balloon 44. Therefore, by expanding the balloon 44, the nozzle 45 can be easily brought closer to the first crack 25, and by deflating the balloon 44, the nozzle 45 can be easily moved away from the first crack 25. The liquid supplied to the balloon 44 is ejected from the nozzle 45 and supplied between the inner membrane 21 and the middle membrane 22 through the first crack 25 formed in the inner membrane 21. In order to bring the nozzle 45 closer to the first crack 25, it is desirable that the nozzle 45 be provided on a crack-forming portion 46 protruding from the outer surface of the balloon 44, for example.

[0100] (8) In this disclosure, the balloon 44 is expanded by supplying a fluid such as a liquid or gas. The balloon 44 forms a first crack 25 by expanding. For example, a crack-forming portion 46 is provided on the outer surface of the expanded balloon 44. The crack-forming portion 46 forms the first crack 25 by coming into contact with the intima 21 of the blood vessel 2. Therefore, the crack-forming portion 46 can be easily brought into contact with the intima 21 by expanding the balloon 44. Thus, the formation of the first crack 25 at a desired location is easy. For example, the balloon 44 is expandable and contracts as the supplied liquid is expelled. By contracting the balloon 44, the crack-forming portion 46 can be easily separated from the inner membrane 21.

[0101] (9) In this disclosure, when the balloon 33 expands, the crack-forming portion 34 forms a first crack 25 that extends around the entire circumference of the blood vessel 2 in the portion of the intima 21 that is more proximal to the lesion portion 20. After the formation of the first crack 25, the balloon 33 deflates. When the balloon 33 expands again, the crack-forming portion 34 forms a second crack 26 around the entire circumference of the blood vessel 2 in the portion of the intima 21 distal to the lesion portion 20.

[0102] After the balloon 33 is re-expanded, the delamination mechanism 4 supplies fluid through the first crack 25 between the intima 21 and media 22 distal to the first crack 25. In this case, as fluid is supplied, the intima 21 located between the first crack 25 and the second crack 26 (the intima 21 to which the lesion 20 is attached) is delaminated, and the delaminated intima 21 separates from the media 22. Therefore, it is possible to prevent unnecessary delamination of the intima 21 distal to the second crack 26. Consequently, the burden on the blood vessel 2 can be reduced.

[0103] (10) In this disclosure, a plurality of nozzles 42 are movable toward and toward each other and can be housed in a tubular sheath 111 in close proximity to each other. The sheath 111 is inserted into a blood vessel 2, for example, along the blood vessel 2. When the sheath 111, which houses the multiple nozzles 42, moves proximally, the multiple nozzles 42 protrude relatively from the sheath 111, moving away from each other. When the sheath 111 from which the multiple nozzles 42 protrude moves distally, the multiple nozzles 42 move closer to each other and are relatively immersed in the sheath 111.

[0104] Multiple nozzles 42, spaced apart from each other, can approach each other to grasp the detached intima 21. That is, the relative immersion of the multiple nozzles 42 into the sheath 111 allows for easy recovery of the detached intima 21 (i.e., the intima 21 to which the lesion 20 is attached). As a result, the lesion 20 can be reliably removed together with the intima 21. In this way, the dissection mechanism 4 used with the sheath 111 also functions as a retrieval mechanism for collecting the intima 21. Therefore, the catheter device 1 does not need to have a separate retrieval mechanism.

[0105] (11) In this disclosure, the recovery mechanism recovers the detached intima 21 (i.e., the intima 21 to which the lesion 20 is attached). Therefore, the lesion 20 can be reliably removed together with the intima 21. If the retrieval mechanism is integrated with the dissection mechanism 4, the catheter device 1 can be made compact.

[0106] (12) In this disclosure, the liquid pressure of the liquid supplied to the peeling mechanism 4 is within a predetermined range. The specified range is 10 mmHg or more and 600 mmHg or less. When the fluid pressure of the liquid supplied to the peeling mechanism 4 is within the specified range, the liquid can effectively peel the intima 21 and reduce the burden that the liquid places on the blood vessel 2.

[0107] (13) In this disclosure, a first crack 25 is formed in the intima 21 of the blood vessel 2. Fluid is supplied between the intima 21 and the media 22 of the blood vessel 2 through the formed first crack 25. As a result, the intima 21 is separated from the media 22. The separated intima 21 is collected. When the intima 21 to which the lesion 20 is attached is separated and collected, the lesion 20 can be reliably removed together with the intima 21. The collected intima 21 is discarded or examined, etc.

[0108] The intima 21 easily separates from the media 22 due to the pressure of the fluid that flows between the intima 21 and the media 22. Therefore, it is not essential to bring the dissection mechanism 4 or other instrument into contact with the blood vessel 2 for the purpose of removing the lesion 20. Moreover, it is possible to prevent the inconvenience of removing the media 22 when removing the intima 21. As a result, the burden on the blood vessel 2 can be reduced.

[0109] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is intended to include, but not in the sense described above, the equivalents of the claims and all modifications within the claims. The constituent elements (technical features) disclosed in each embodiment are combinable with each other, and new technical features can be formed by these combinations. Furthermore, the independent and dependent claims described in the claims can be combined with each other in any combination, regardless of the form of reference. Moreover, the claims use a form in which claims referencing two or more other claims (multi-claim form), but are not limited to this. A form in which multi-claims referencing at least one multi-claim (multi-multi-claim) may also be used. [Explanation of Symbols]

[0110] 1. Catheter device 111 Sheath 2 blood vessels 20 Lesion 21 Intima 22 Media 25. The First Crack (Crack) 33 Balloons 4. Peeling mechanism (recovery mechanism) 42 nozzles 421 Proximal part 422 Tip part 43 Supply pipe 44 Balloons 45 nozzles 46 Crack formation area 48 nozzles

Claims

1. A delamination mechanism that supplies fluid between the intima and the media of a blood vessel through a crack formed in the intima of the blood vessel, thereby separating the intima to which the lesion is attached from the media. A catheter device characterized by comprising the following features.

2. The aforementioned peeling mechanism is A supply tube inserted into the blood vessel and for supplying the fluid toward the distal end, A nozzle for supplying the liquid supplied through the supply pipe between the inner membrane and the middle membrane through the crack, The catheter device according to claim 1, characterized by comprising:

3. The catheter device according to claim 2, characterized in that the dissection mechanism comprises a plurality of nozzles.

4. The catheter device according to claim 2, characterized in that the nozzle is rotatable in the circumferential direction of the blood vessel when inserted into the blood vessel.

5. The nozzle is bent, The base portion extends diagonally from the supply pipe in the insertion direction, The catheter device according to claim 2, characterized in that the tip portion is aligned with the insertion direction.

6. The aforementioned peeling mechanism is A balloon that expands into a cylindrical shape when the aforementioned liquid is supplied, A nozzle is provided on the periphery of the end face of the expanded balloon, for supplying the liquid supplied to the balloon between the inner membrane and the middle membrane through the crack. The catheter device according to claim 1, characterized by comprising:

7. The aforementioned peeling mechanism is A balloon that expands when the aforementioned liquid is supplied, A crack-forming portion is provided on the outer surface of the expanded balloon, and the crack is formed when the balloon expands, The outer surface is provided with a plurality of nozzles for supplying the liquid supplied to the balloon between the inner membrane and the middle membrane through the crack, The catheter device according to claim 1, characterized by comprising:

8. The balloon that expands to form the aforementioned crack The catheter device according to claim 1, further comprising the following:

9. The aforementioned balloon, It is expandable, The crack is formed by expanding proximal to the lesion. After the crack forms, it shrinks, The area distal to the aforementioned lesion is then expanded again. The catheter device according to claim 8, characterized in that the separation mechanism supplies the fluid between the intima and media through the crack when the balloon is re-expanded distally.

10. The device further comprises a tubular sheath capable of housing multiple nozzles within its lumen, When the sheath moves proximal, the multiple nozzles protrude relatively from the sheath so as to move away from each other. When the sheath moves distally, the multiple nozzles move closer to each other and are relatively immersed in the sheath. The catheter device according to claim 3, characterized in that the plurality of nozzles approaching each other are capable of sandwiching the detached inner membrane.

11. A recovery mechanism for collecting the detached inner membrane. The catheter device according to claim 1, further comprising the following:

12. The catheter device according to claim 1, characterized in that the liquid pressure of the liquid supplied to the peeling mechanism is 10 mmHg or more and 600 mmHg or less.

13. It forms a crack in the inner lining of the blood vessel. By supplying fluid between the intima and the media of the blood vessel through the formed crack, the intima is separated from the media. A recovery method characterized by recovering the detached inner membrane.

Images