In-tube safety cage
The implementation of a helical safety cage within the vascular occlusion creates a protective barrier, allowing for aggressive treatment of chronic occlusions without risking vessel damage, thus enhancing treatment efficacy and safety.
Patent Information
- Application Number
- JP2024569095
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-06-09
- Filing Date
- 2023-06-01
- Publication Date
- 2025-06-12
AI Technical Summary
Existing catheter technologies struggle to effectively treat chronic vascular occlusions due to the increased size, hardness, and adherence of these occlusions, leading to reduced efficacy of standard atherectomy and thrombus removal tools while risking damage to the blood vessel.
The use of a helical safety cage that is rotated within the vascular occlusion to create a safety barrier between the blood vessel wall and the treatment tool, allowing for the use of more aggressive treatment devices without risking damage to the vessel.
This approach enables safer and more effective treatment of chronic vascular occlusions by preventing trauma to the blood vessel wall and allowing for a wider range of treatment tools to be used, while maintaining the safety of the device.
Smart Images
Figure 2025517963000001_ABST
Abstract
Description
Technical Field
[0001] The following generally relates to catheter technology, vascular treatment, lesion treatment technology, and related technologies.
Background Art
[0002] Treatment of intravascular occlusion generally becomes more difficult as the age of the occlusion increases. Occlusions typically become larger, harder, and more strongly adhered to the affected vasculature as they become more chronic. As these occlusions become more chronic, the effectiveness of standard atherectomy and thrombus removal tools decreases.
[0003] In developing new tools for treating these chronic cases, increasing the aggressiveness of the tool (sharpness of contact features, contact force, movement speed) provides improved efficacy. However, the aggressiveness of the tool needs to be limited to prevent damage to the treated blood vessel. Maintaining the safety of the device often results in reducing the aggressiveness of the device to the point where the device is no longer effective.
Summary of the Invention
Problems to be Solved by the Invention
[0004] The following discloses certain improvements for overcoming these and other problems.
Means for Solving the Problems
[0005] In some embodiments disclosed herein, an intravascular treatment device includes an intravascular catheter, a helical cage configured to be rotated within a vascular occlusion disposed within a blood vessel of a related patient by the intravascular catheter, and a treatment device configured to be moved to a position within the helical cage while the helical cage is being rotated within the vascular occlusion and further configured to be operated to treat the vascular occlusion while being disposed within the helical cage.
[0006] In some embodiments disclosed herein, a vascular treatment method includes inserting a helical cage into a patient's blood vessel associated with an intravascular occlusion disposed within the blood vessel, screwing the helical cage into the intravascular occlusion disposed within the blood vessel, after screwing the cage into the intravascular occlusion, inserting a treatment device into the helical cage, operating the treatment device while the treatment device is inserted within the helical cage to apply treatment to treat the intravascular occlusion, removing the treatment device from the helical cage, and removing the helical cage from the blood vessel.
[0007] In some embodiments disclosed herein, a vascular treatment system includes a treatment device and a helical cage configured to be rotated within an intravascular occlusion disposed within a patient's associated blood vessel, the cage having a diameter smaller than the diameter of the blood vessel and sized to accommodate the treatment device.
[0008] One advantage is to provide a safety barrier between the blood vessel wall and the treatment tool.
[0009] Another advantage is to prevent trauma to the blood vessel wall.
[0010] Another advantage is to enable a wider range of treatment tools to be used to treat blood clots within the blood vessel by using a safety barrier between the treatment tool and the blood vessel wall.
[0011] Another advantage is to provide a removable safety barrier between the blood vessel wall and the treatment tool.
[0012] A given embodiment may or may not provide any, one, two, more, or all of the aforementioned advantages and / or may provide other advantages that will be apparent to those skilled in the art upon reading and understanding the present disclosure.
[0013] The present disclosure may take the form of various components and combinations of components, as well as various steps and combinations of steps. The drawings are for the purpose of illustrating preferred embodiments only and should not be construed as limiting the present disclosure.
Brief Description of the Drawings
[0014]
Figure 1
Figure 2
Figure 3
Figure 4
Mode for Carrying Out the Invention
[0015] In an intravascular thrombus reduction procedure, the thrombus material is removed using a reduction tool such as a mechanical cutter or a laser catheter that performs laser ablation. In such a procedure, a major concern is that mechanical cutting or laser ablation may cut into the vessel wall and even cause weakening or rupture of the vessel wall.
[0016] Disclosed below is a helical intravascular safety cage designed to be rotated within a treatment site. The diameter of the safety cage is selected to be slightly smaller than the diameter of the vascular lumen such that when screwed into the treatment site, the thrombus material is mostly inside the helical safety cage and the wall of the vascular lumen is outside the safety cage. After the helical safety cage is so positioned, the reduction tool is introduced and operated to reduce the thrombus material within the safety cage while the vessel wall is safely positioned outside the safety cage. In the case of laser ablation, the operating distance of the laser light is typically about several tens of microns so that the helical safety cage provides appropriate protection against the vessel wall.
[0017] The helical safety cage is suitably made from, for example, stainless steel, nitinol, or a shape memory polymer. In the case of the latter two, the nitinol or shape memory polymer is set to a helical shape when designed and then folded to be stored within the lumen of the delivery catheter and can expand to its set size when deployed. After deployment of the helical safety cage at the treatment site, the same or a different catheter can be used to deliver the reduction tool to the treatment site. After the treatment is completed, the helical safety cage is removed by rotating it in a rotational direction opposite to that used for deployment and then retracted into the lumen of the catheter.
[0018] Referring to FIG. 1, an exemplary vascular treatment device 10 is schematically shown. As shown in FIG. 1, the vascular treatment device 10 is insertable into a blood vessel for treating a lesion (or blood clot, or occlusion, etc.) within the blood vessel. The vascular treatment device 10 includes, for example, an intravascular catheter 12 and a helical safety cage 14 disposed at the distal end 13 of the intravascular catheter 12 and configured to be rotated within a blood vessel occlusion disposed within the blood vessel by the intravascular catheter 12. It should be noted that FIG. 1 is not drawn to scale and the intravascular catheter 12 can have a length suitable for inserting the catheter 12 into the blood vessel and delivering it through the vasculature along a (presumably serpentine) path to the distal end 13 to the treatment site, and the length of the catheter 12 is sufficient such that when the distal end 13 reaches the treatment site, the rotation control unit 18 still remains outside the patient.
[0019] The treatment device 16 (schematically shown in FIG. 1 as a cylinder) is configured to be moved to a position inside the helical safety cage 14 while the helical safety cage 14 is rotated within the vascular occlusion, and further configured to operate to treat the vascular occlusion while being disposed inside the helical cage 14. The treatment device 16 is configured to be moved to a position inside the helical cage 14 while the helical cage 14 is rotated within the vascular occlusion, and to operate to treat the vascular occlusion using the same intravascular catheter 12 that is used to rotate the helical cage 14 within the vascular occlusion. In one embodiment, the treatment device 16 includes an occlusion reduction tool configured to fit within the helical cage 14 to reduce the vascular occlusion. In another embodiment, the treatment device 16 includes a laser ablation catheter configured to fit within the helical cage 14 to provide ablation treatment to the vascular occlusion.
[0020] The rotation control unit 18 is disposed at the proximal end 15 of the intravascular catheter 12. The rotation control unit 18 is operably connected to rotate the helical cage 14. The rotation control unit 18 can be manually rotated by a user or can be motorized (not shown) by a motor. In some embodiments, as shown in FIG. 1, a second intravascular catheter 20 is disposed within the intravascular catheter 12 that coaxially surrounds the second intravascular catheter 20. The rotation control unit 18 is operably connected to rotate the helical cage 14 by the second intravascular catheter 20. To do so, the second intravascular catheter 20 is configured to move the treatment device 16 to a position inside the helical cage 14 while the helical cage 14 is being rotated within the vascular occlusion, and to operate the treatment device 16 to treat the vascular occlusion.
[0021] The exemplary catheter 12 can have other features not shown in FIG. 1, for example, a guidewire lumen extending along the entire length of the catheter 12 for over-the-wire (OTW) delivery along a guidewire pre-inserted intravascularly along the path to the treatment site, or a shorter guidewire lumen having an exit port in a rapid exchange (RX) catheter design. As a further example, other contemplated variations include the addition of an ultrasonic transducer at or near the distal end 13 for imaging the treatment site, the addition of one or more radiopaque markers on the catheter 12 to enable visualization by a suitable interventional imaging modality, and / or others. In some embodiments, the proximal end may be connected to a vacuum pump (not shown) to perform vacuum aspiration through the lumen of the sheath 22 or the second intravascular catheter 20 to remove the thrombus material excised by the treatment device 16.
[0022] FIG. 1 shows an embodiment where the catheter 12 is an outer sheath that delivers the helical cage 14, and the treatment device 16 is attached to an inner intravascular catheter 20 disposed within a lumen extending through the outer sheath catheter 12. This design has significant advantages. The sheath catheter 12 can be rotated by a handle or other rotational control 18 to rotate the helical cage 14 to a predetermined position to protect the blood vessel wall. Thereafter, both the helical cage 14 and the outer sheath catheter 12 can remain in place, with the helical cage 14 remaining attached to the distal end 13 of the outer sheath catheter 12, providing a path traced through the vasculature in which the treatment device 16 can be operated via the inner intravascular catheter 20.
[0023] However, in other embodiments (not shown), it is contemplated to use completely separate and unrelated catheters for these operations. For example, a first catheter can be used to deliver the helical cage 14. Then, this first catheter is withdrawn from the vasculature, and a second catheter is inserted into the vasculature to deliver the treatment device 16 and then withdrawn. The first catheter is then reinserted to retrieve the helical safety cage 14. In such embodiments, the first catheter suitably includes a mechanically or electrically actuated clamp or the like that operates as a release / pickup mechanism. Using this mechanism, the helical safety cage 14 can be released after being in a fixed position within the thrombus so that the first catheter can be removed while leaving the helical safety cage 14 in place. During the subsequent retrieval step, the release / pickup mechanism recaptures the helical safety cage 14 to retrieve the helical safety cage 14.
[0024] Referring to FIGS. 2 and 3, the helical cage 14 is shown in a side view (FIG. 2) and a perspective view (FIG. 3) from a viewpoint close to the central axis of the helix. The helical cage 14 has a diameter D shown in FIGS. 2 and 3 H and is preferably slightly smaller than the diameter of the blood vessel at the treatment site. The helical cage 14 also has a corresponding radius R not shown in FIGS. 2 and 3 H where R H = 0.5×D H The helical cage 14 is screwed into the thrombus material and is thus held in place near the inner wall of the blood vessel by the thrombus material. If the blood vessel has a diameter D BV and a corresponding blood vessel radius R BV = 0.5×D BV the outermost portion of the thrombus corresponding to the annulus between the radius R H and R BV is located outside the helical cage 14 and is thus not removed by the treatment instrument 16 operating within the helical cage 14. The diameter D of the helical cage 14 HThe option is the desired diameter of the core of the blood cake material to be excised (which is equal to D H ignoring the thickness of the stainless steel or other wire that makes up the helical cage 14) and the radius R H between R BV and R H and is appropriately selected based on the acceptable residual annulus of the blood cake material. For therapeutic purposes, typical design considerations are that the open lumen resulting from the treatment should have a diameter of approximately D
[0025] The helical cage 14 also has a helical pitch P H labeled only in the side view of FIG. 2. Note that FIG. 2 and FIG. 3 and the diagrams, and a specific pitch P H are shown schematically. Usually, the pitch P H determines the size of the gap between adjacent turns of the helical coil 14, together with the wire diameter of the stainless steel or other wire wound helically to form the helical cage 14. Ignoring the finite wire diameter, this gap is thus equal to the pitch P H This gap is the space through which the treatment device 16 can in principle pass operably in order not to cut undesirably into the inner wall of the blood vessel. Thus, in order to avoid this undesirable cut into the blood vessel wall, the pitch P H should be selected to be small enough (along with the actual wire diameter) such that the resulting gap is too small for the treatment device 16 to pass operably through. The appropriate pitch P H can be selected based on the nature of the treatment device 16. For example, when the treatment device 16 is a laser ablation catheter, the physical size of the tip of the laser catheter is the pitch P HIf it is below an acceptable maximum value, the cutting laser aperture passes through the gap between adjacent turns of the helical coil 14, preventing ablation of the blood vessel inner wall. In this regard, it should be noted again that the operating distance of the laser light of a typical laser ablation laser aperture is typically on the order of several tens of microns. Similarly, if the treatment device 16 is a reduction tool that uses a rotary or other type of cutter, the size of the cutter and its attachment to the distal tip of the inner catheter 20 are related to the pitch P H If it is below some maximum allowable value, the cutter passes through the gap between adjacent turns of the helical coil 14, preventing it from cutting into the inner blood vessel wall.
[0026] The helical cage 14 can be made of, for example, stainless steel, nitinol, or a shape memory polymer. The helical cage 14 has a plurality of turns 24 that form the helical cage 14. Referring particularly to the proximal perspective view of FIG. 3, the helical cage 14 optionally has a distal end 26 that is directed inwardly toward the axis of the helical cage 14. This inwardly curved end 26 is the tip when the helical cage 14 is screwed into the blood clot, and the inwardly curved end 26 reduces the likelihood that the end will be misdirected and embedded in the blood vessel wall.
[0027] Referring to FIG. 4, an exemplary embodiment of an intravascular treatment method 100 using the intravascular treatment device 10 is schematically shown as a flowchart. In operation 102, the intravascular catheter 12 is inserted into the blood vessel to place the helical cage 14 in proximity to the blood clot within the blood vessel. In operation 104, the helical cage 14 is then screwed into the vascular occlusion. In operation 106, the treatment device 16 is inserted inside the helical cage 14. In operation 108, the treatment device 16 is operated (e.g., using an occlusion reduction tool, a laser ablation catheter, etc.) to apply treatment while being inserted inside the helical cage 14. When the treatment is completed, in operation 110, the treatment device 16 is removed from the helical cage 14. In operation 112, the helical cage 14 is removed from the blood vessel. In operation 114, the intravascular catheter 12 is withdrawn from the blood vessel. As described above, using the device of FIG. 1, operations 106, 108, and 110 can be performed with the outer sheath catheter 12 remaining in place and attached to the deployed helical safety cage 14, and thus the additional steps performed by a human operator to use the helical safety cage 14 are only the additional steps 104 and 112.
[0028] The helical cage 14 should have sufficient density and thickness to prevent the treatment device 16 from contacting the blood vessel wall. For example, the wire diameter of the surgical stainless steel or other metal, ceramic, or polymer that makes up the helical safety cage 14 can be selected to provide a sufficient safety barrier with sufficient rigidity to allow the helical safety cage 14 to be screwed into the blood clot. The helical cage 14 must also be durable so that contact with the treatment device 16 operating inside it does not cause damage. However, note that the helical cage can be manufactured at low cost and is therefore, in some embodiments, a consumable part used only for a single intravascular treatment. Therefore, it only needs to be sufficiently durable for a single treatment session. Alternatively, if the helical cage 14 is made of surgical stainless steel or another durable material that is autoclaveable, it can be sterilized between procedures and reused.
[0029] As shown in FIG. 3, one embodiment of the helical cage 14 includes a tip 26 that is inclined inwardly toward the center of the blood vessel to reduce the likelihood of penetration when inserting the helical cage 14. The helical cage 14 can be folded down inside the intravascular catheter 12 or shape memory action can be used, so that it can pass through a smaller access size and is easily navigated through the blood vessel. When the tip of the intravascular catheter 12 reaches the treatment site, the helical cage 14 can be expanded to the desired size and screwed out of the intravascular catheter 12 so that it passes itself between the occlusion and the blood vessel wall. When the helical cage 14 is screwed into place, the treatment device 16 can be operated inside the helical cage 14 with the risk of the treatment device 16 damaging the blood vessel wall reduced. When the treatment is complete, the helical cage 14 can be rotated in the opposite direction to release / remove it from the blood vessel and return it to a folded state inside the intravascular catheter 12 for removal from the body.
[0030] The present disclosure has been described with reference to the preferred embodiments. Modifications and variations may occur to others upon reading and understanding the foregoing detailed description. All such modifications and variations are intended to be included within the scope of the exemplary embodiments as long as they fall within the scope of the appended claims or their equivalents.
Claims
1. An intravascular catheter, a helical cage configured to be rotated by the intravascular catheter within a vascular occlusion disposed within a blood vessel of a patient, a treatment device configured to be moved to a position inside the helical cage while the helical cage is being rotated within the vascular occlusion and further configured to operate to treat the vascular occlusion while being disposed inside the helical cage, An intravascular treatment device having the above components.
2. The intravascular treatment device according to claim 1, wherein the treatment device is configured to be moved to the position inside the helical cage while the helical cage is being rotated within the vascular occlusion and to operate to treat the vascular occlusion using the same intravascular catheter used to rotate the helical cage within the vascular occlusion.
3. A second intravascular catheter different from the intravascular catheter, further comprising, wherein the second intravascular catheter is configured to move the treatment device to the position inside the helical cage while the helical cage is being rotated within the vascular occlusion and to operate the treatment device to treat the vascular occlusion. The intravascular treatment device according to claim 1.
4. The intravascular treatment device according to any one of claims 1 to 3, wherein the treatment device is sized to fit within the diameter of the helical cage.
5. The intravascular treatment device according to any one of claims 1 to 4, wherein the helical cage comprises stainless steel.
6. The intravascular treatment device according to any one of claims 1 to 4, wherein the helical cage comprises nitinol.
7. The intravascular treatment device according to any one of claims 1 to 4, wherein the helical cage comprises a shape memory polymer.
8. The treatment device, comprises an occlusion reduction tool configured to fit within the helical cage to reduce the vascular occlusion. The intravascular treatment device according to any one of claims 1 to 7.
9. The treatment device, comprises a laser ablation catheter configured to fit within the helical cage to provide ablation treatment to the vascular occlusion. The intravascular treatment device according to any one of claims 1 to 7.
10. The intravascular treatment device according to any one of claims 1 to 9, wherein the helical cage has a distal end directed inwardly toward the axis of the helical cage.
11. Inserting a helical cage into a blood vessel of a patient in which a blood vessel occlusion is located within the blood vessel and screwing the helical cage into the blood vessel occlusion located within the blood vessel; After screwing the cage into the blood vessel occlusion, inserting a treatment device inside the helical cage; Operating the treatment device to apply a treatment for treating the blood vessel occlusion while the treatment device is inserted inside the helical cage; Removing the treatment device from the helical cage; Removing the helical cage from the blood vessel; A blood vessel treatment method comprising:
12. The step of applying the treatment comprises: Applying the treatment using the treatment device having a debulking tool; The blood vessel treatment method according to claim 11, comprising:
13. The step of applying the treatment comprises: Applying the treatment using the treatment device having a laser ablation catheter; The blood vessel treatment method according to claim 11, comprising:
14. A treatment device; A helical cage configured to be rotated within a blood vessel occlusion located within a blood vessel of a patient, the cage having a diameter smaller than the diameter of the blood vessel and sized to accommodate the treatment device; An intravascular treatment device comprising:
15. The intravascular treatment device according to claim 14, wherein the helical cage has a distal end directed inwardly toward the axis of the helical cage.
16. The treatment device comprises: A debulking tool configured to fit within the helical cage for debulking the blood vessel occlusion, or A laser ablation catheter configured to fit within the helical cage for providing ablation treatment to the blood vessel occlusion; The intravascular treatment device according to any one of claims 14 and 15, comprising one of the above.
17. The intravascular treatment device according to any one of claims 14 to 16, wherein the helical cage comprises one of stainless steel, nitinol, or a shape memory polymer.
18. Further comprising an intravascular catheter The helical cage is configured to be rotated within a vascular occlusion disposed within a blood vessel of an associated patient by the intravascular catheter. The treatment device is configured to be moved to a position within the helical cage while the helical cage is being rotated within the vascular occlusion, and further configured to be operated to treat the vascular occlusion while being disposed within the helical cage. The intravascular treatment device according to any one of claims 14 to 17.
19. The treatment device is configured to be moved to the position inside the helical cage while the helical cage is being rotated within the vascular occlusion, and to be operated to treat the vascular occlusion using the same intravascular catheter that is used to rotate the helical cage within the vascular occlusion. The intravascular treatment device according to claim 18.
20. A second intravascular catheter different from the intravascular catheter. further comprising The second intravascular catheter is configured to move the treatment device to the position inside the helical cage while the helical cage is being rotated within the vascular occlusion, and to operate the treatment device to treat the vascular occlusion. The intravascular treatment device according to claim 18.