Self-push occlusion transfer catheter with controlled manipulation

Abstract

An endovascular treatment device (10) comprises a catheter (12) and a plurality of mutually parallel cutting instruments (14, 16, 18) disposed at least at a distal end of the catheter. Each cutting instrument is configured to engage with a portion of a clot disposed in a blood vessel into which the catheter is advanced. Each cutting instrument may be independently advanced into the clot.

Description

Technical Field

[0001] The following generally relates to the fields of catheters, mechanical thrombectomy, spectroscopy, and related fields. Background Art

[0002] A chronic total occlusion (CTO) is a complete blockage of a blood vessel. To treat such a CTO (or other nearly complete occlusion) in a typical intervascular treatment workflow, a guidewire is first inserted into the vessel and manipulated to cross the occlusion (sometimes referred to herein as a clot). After crossing the occlusion, an interventional catheter (i.e., a balloon / stent device, etc.) is inserted along the guidewire to enter the CTO, thereby performing treatment. Because the guidewire is flexible, it is difficult and sometimes impossible to pass the guidewire through the CTO due to issues related to guidewire buckling. The problem is that the guidewire is not stiff enough to push it through the CTO without buckling. In addition, the guidewire should remain inside the vessel, so maneuverability is required during advancement through the CTO; otherwise, the guidewire may be inadvertently pushed into or even through the vessel wall, causing undesirable damage or rupture to the vessel. In order to know whether the guidewire or catheter is inside the (blocked) lumen, inside the vascular tissue, or has completely pierced the vessel wall, sensing is beneficial in providing feedback.

[0003] One way to obtain such feedback is by employing interventional imaging, which uses modalities such as computed tomography (CT) or another X-ray imaging modality, or ultrasound imaging. However, although these imaging techniques can be used to track the progress of the guidewire toward the occlusion, they have limited spatial resolution and contrast, and therefore may not accurately detect vessel penetration when the operator attempts to engage the tip of the guidewire into the occlusion. An experienced operator may be able to judge the penetrated tissue by manual tactile feedback as he or she advances the guidewire into the occluded area and / or by monitoring the aspirated material when aspiration is performed during traversal, but these may also be inaccurate and misleading to the operator.

[0004] Certain improvements that overcome these and other problems are disclosed below. Summary of the Invention

[0005] In some embodiments disclosed herein, an intravascular treatment device includes a catheter; and a plurality of mutually parallel cutting instruments disposed at least at a distal end of the catheter. Each cutting instrument is configured to engage a portion of a clot disposed in a blood vessel into which the catheter is advanced. Each cutting instrument is independently advanceable into the clot.

[0006] In some embodiments disclosed herein, an intravascular treatment device includes a flexible catheter comprising at least three mutually parallel flexible sub-catheters. Each sub-catheter has a tip configured to engage a portion of a blood clot. Each sub-catheter is independently movable relative to the other sub-catheters in the at least three mutually parallel flexible sub-catheters.

[0007] In some embodiments disclosed herein, an occlusion traversal method includes performing electrical spectroscopy measurements on at least one of the cutting instruments, which is positioned at least at a distal end of a catheter to engage a portion of a clot disposed in a blood vessel into which the catheter is advanced; and determining a type of tissue engaged with the at least one cutting instrument based on the electrical spectroscopy measurements.

[0008] One advantage resides in providing feedback to correct advancement of the catheter into the occluded area.

[0009] Another advantage resides in providing a catheter that provides a tensile force component to improve the ability and efficiency of penetrating an occlusion during traversal of the occlusion.

[0010] Another advantage resides in providing a catheter having multiple cutting instruments (eg, daughter catheters) to engage an occluded catheter.

[0011] Another advantage resides in measuring the impedance of the cutting instrument of the catheter to determine the type of tissue engaged with the catheter.

[0012] Another advantage resides in providing an optical measurement of the type of tissue engaged with the catheter.

[0013] A given embodiment may provide none of the aforementioned advantages, one of the aforementioned advantages, two of the aforementioned advantages, more of the aforementioned advantages, or all of the aforementioned advantages, and / or may provide other advantages that will be apparent to one of ordinary skill in the art upon reading and understanding this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present disclosure may take the form of various components and arrangements of components, and may take the form of various steps and arrangements of steps.The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting the present disclosure.

[0015] Figure 1 and 2 Two embodiments of intravascular treatment devices according to the present disclosure are diagrammatically illustrated.

[0016] Figure 3 Diagrammatically illustrates the use of Figure 1 Methods of performing intravascular treatment methods using devices. DETAILED DESCRIPTION

[0017] In embodiments disclosed herein, a catheter (e.g., a guidewire in some embodiments) provides a pulling force to help penetrate the occlusion to achieve passage through the occlusion. This pulling force can advantageously reduce or eliminate the use of a thrust to achieve passage through. As previously described, attempting to pass through an occlusion by pushing a catheter or guidewire through the occlusion may cause the catheter to buckle and be unable or difficult to achieve passage through. This is because the thrust is applied to the proximal end of the catheter, i.e., at the end located outside the patient's vascular system, and the thrust is transmitted along the entire length of the catheter disposed in the vascular system to reach its distal end that engages the occlusion. Since the catheter is flexible to accommodate the tortuosity of the vascular system through which it passes, the thrust transmitted may cause the catheter to buckle. In contrast, the catheter disclosed herein employs a plurality of mutually parallel cutting instruments disposed at least at the distal end of the catheter (and in some embodiments, including sub-catheters extending along the length of the catheter or other catheters). Each of the mutually parallel cutting instruments can move or slide relative to the other cutting instruments. If there are at least three cutting instruments, the one cutting instrument that is currently moving generates less friction than the remaining two (or more) cutting instruments that are not currently moving. See Scali et al., “Ovipositor-inspired steerable needle: design and preliminary experimental evaluation” (2018 Bioinspir. Biom. 13). 016006). Thus, the non-moving cutting instrument provides friction that tends to keep the tip of the catheter in a fixed position so as to allow one moving cutting instrument to be advanced into the clot. This process is cyclically repeated for each cutting instrument in sequence to advance the tip of the catheter as a whole through the clot, thereby achieving (or at least assisting in achieving) traversal of the clot. In various embodiments, the cyclic advancement of each cutting instrument can then be achieved manually (e.g., by a human operator sequentially advancing each cutting instrument comprising the sub-catheters) or by a mechanical or electromechanical mechanism.

[0018] Another advantage of the illustrative catheter disclosed herein is that the cutting instrument provides a platform for performing tissue measurements. In one approach, each of the cutting instruments is conductive and serves as an electrode in an impedance measurement (or other type of electrical property measurement). For example, a spectrum impedance measurement between a pair of cutting instruments can provide a tissue signature for identifying the type of tissue (e.g., blood, clotted tissue, blood vessel wall, etc.) disposed between the pair of cutting instruments. See, for example, Gabriel et al., “The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues” (Phys. Med. Biol. vol. 41 pp. 2271-93 (1996)); Ambrogio et al., “Investigation of Blood Coagulation Using Impedance Spectroscopy: Toward Innovative Biomarkers to Assess Fibrinogenesis and Clot Retraction” (Biomedicines 2022, 10, 1833).

[0019] In another method, the cutting instrument includes a sub-catheter, each sub-catheter including one or more optical fibers (or waveguides) for injecting light into the distal tip of the sub-catheter. By arranging the optical fiber ends of adjacent cutting instruments to face each other, light can be transmitted through the gap between adjacent cutting instruments so as to perform optical measurements on the tissue arranged between the cutting instruments. Optical spectroscopy can thus be performed to provide a tissue signature for identifying the type of tissue (e.g., blood, clot tissue, blood vessel wall, etc.) arranged between the pair of cutting instruments. See, for example, Skyrman et al., “Clotcompositioncharacterization using diffuse reflectance spectroscopy in acuteischemicstroke” (Biomedical Optics Express Vol. 13, No. 6 (June 2022)). Skyrman et al., “Identifying clotcomposition using intravascular diffuse reflectancespectroscopy in aporcinemodel of endovascular thrombectomy” (J. NeuroInterventSurg April 2021). In some embodiments, a pair (or more) of optical fibers may be included. One optical fiber can be used to emit light, while another optical fiber can be used to receive light.

[0020] Although primarily described in terms of spectral impedance measurements, the systems and methods described herein may also include optical sensing requiring optical fibers (e.g., optical spectroscopy, fluorescence spectroscopy, Raman spectroscopy, optical coherence tomography, etc.), pressure sensors in the sub-catheters (i.e., for measuring tissue resistance), acoustic sensors (i.e., measuring acoustic properties), etc. Other types of sensors, including cutting instruments, are also contemplated for sensing the type of tissue engaged with the cutting instrument.

[0021] refer to Figure 1 , diagrammatically illustrates an intravascular treatment device 10 for treating a clot C or an occlusion (e.g., a CTO or nearly complete occlusion) in a blood vessel V. As used herein, "clot" and "occlusion" are synonymous and refer to a complete or nearly complete blockage of blood flow through a blood vessel. The treatment device 10 includes a flexible catheter (or guidewire) 12 that is advanced into the blood vessel V and adjacent to the clot C. The flexible catheter 12 is flexible in the sense that the catheter 12 can be pushed through a tortuous vascular path to move its distal end to the clot C, wherein the flexible catheter 12 bends or flexes during the insertion process to conform to the tortuous vascular path. In some embodiments, the catheter 12 can be, for example, a guidewire. In Figure 1In the first embodiment shown, the plurality of mutually parallel cutting instruments 14 , 16 , 18 comprise a sub-conduit of the catheter 12 extending to the distal end of the catheter 12 (ie, adjacent or proximate to the clot C). Figure 1 Three mutually parallel cutting instruments 14, 16, 18 are shown; however, any suitable number of at least three cutting instruments may be implemented. Each cutting instrument 14, 16, 18 is independently advanceable into the clot C. Each cutting instrument 14, 16, 18 is configured to engage a portion of the clot C, for example, by having a tapered or pointed tip. The cutting instruments 14, 16, 18 of the catheter 12 can be used to generate a pulling force to pull the catheter 12 through the clot C, thereby traversing the clot C.

[0022] After the catheter 12 has traversed the clot C, various types of treatments can be applied. In some embodiments, the illustrative catheter 12 is a guidewire. In such embodiments, after the guidewire 12 has traversed the clot 12, a second catheter (not shown) is inserted along the guidewire 12 by inserting the proximal end of the guidewire 12 into the lumen of the second catheter, such that the guidewire 12 can guide the distal end of the second catheter all the way to the clot C (and possibly a short distance beyond the clot C). The second catheter suitably carries an angioplasty balloon, a deployable stent, a mechanical or laser cutter, and / or other therapeutic components to treat the clot C through angioplasty, stent placement, thrombectomy, etc.

[0023] In other contemplated embodiments, the illustrated catheter 12 may be a second catheter inserted along a previously inserted (and much smaller diameter) guidewire via the guidewire lumen 21. In such cases, the illustrated catheter 12 suitably carries a therapeutic component. Simultaneously, the guidewire is used to traverse the clot C as disclosed herein and also carries a therapeutic component (not shown) for treating the clot C.

[0024] The sub-conduits 14, 16, 18 of the catheter 12 are held together in a mutually parallel bundle by a suitable retaining mechanism 19. In the illustrative example, the retaining mechanism includes a carrier catheter 19 having a lumen, and the sub-conduits 14, 16, 18 are disposed inside the lumen. In another contemplated embodiment, the retaining mechanism may include an interlocking mechanism built into the sub-conduits 14, 16, 18 themselves, such as mating longitudinal keyed edges and slots (not shown) of the sub-conduits 14, 16, 18 that engage to lock the sub-conduits 14, 16, 18 into a mutually parallel arrangement. In either case, the retaining mechanism 19 allows the sub-conduits 14, 16, 18 to move or slide relative to each other, and more specifically allows one of the sub-conduits (e.g., sub-conduit 18) to do so at any given time, while the other sub-conduits (e.g., sub-conduits 14, 16) may or may not be fixed. Such movement is performed periodically to continuously advance each sub-catheter in turn, for example, advance and then retract sub-catheter 18, then advance and then retract sub-catheter 14, and then advance and then retract sub-catheter 16, and then advance and then retract sub-catheter 18, and so on. In another example, each of sub-catheters 14, 16, 18 can be advanced, and then the retaining mechanism 19 can be pulled forward to retract sub-catheters 14, 16, 18. This process can be repeated as needed. In another example, the catheter 12 can be manipulated so that each sub-catheter 14, 16, 18 can be advanced with different movements. These are merely examples and should not be construed as limiting.

[0025] To illustrate, Figure 1 As shown, a first cutting instrument 14 is advanced out of the catheter 12 and engages a portion of the clot C. A second cutting instrument 16 is partially advanced out of the catheter 12. A third cutting instrument 18 is shown disposed within the catheter 12. Each of the cutting instruments 14, 16, 18 includes serrations 20, such as the illustrative serrations or serration structure 20, configured to engage a portion of the clot C. The serrations 20 can anchor the extended end of the daughter catheter 18 in the clot C such that when the daughter catheter 18 is extended and then withdrawn, the serrations 20 anchor the daughter catheter 18 to facilitate drawing the remainder of the catheter 12 deeper into the clot C. This mechanism for drawing the catheter 12 into the clot C for passage therethrough bears some resemblance to the biomechanical mechanism by which the ovipositor of a parasitic wasp penetrates into a host to deposit eggs. See “Ovipositor-inspired steerable needle: design and preliminary experimental evaluation” by Scali et al. (2018 Bioinspir. Biomim. 13 016006).

[0026] The catheter 12 may include other components, such as the illustrated central lumen 21 for aspiration or for receiving a guidewire (if the catheter 12 is not itself a guidewire), etc. As another example, the catheter 12 may carry a therapeutic device (not shown, such as an angioplasty balloon, a stent delivery device, a cutting tool, etc.).

[0027] In an optical embodiment, the electronic processing device 24 includes a light source (not shown) coupled to send light into the optical fiber of the first cutting instrument 16 and an optical sensor (not shown) coupled to receive light from the optical fiber of the second cutting instrument 16 after the light passes out of the aperture at the distal end of the first cutting instrument 14 and into the aperture at the distal end of the second cutting instrument. The light is suitably multispectral to enable measurement of an optical spectrum that serves as a signature of the material disposed between the pair of cutting instruments, thereby enabling accurate determination of whether the tissue is, for example, clot material, vessel wall material, or blood.

[0028] In another example, the electronic processing device 24 may include a fluorophore (or molecular marker) delivery device configured to deliver a compound in the vessel V to enable imaging of the vessel V, the clot C, and / or the portion of the catheter 12 including the sub-catheters 14, 16, 18. In some examples, the autofluorescence process may be induced by the presence of collagen and elastin in the wall of the vessel V. In another example, the cutting instruments 14, 16, 18 include ultrasound sensors, and tissue determination may be based on ultrasound measurements. Typically, the sensor may include at least two of a plurality of mutually parallel cutting instruments 14, 16, 18, wherein the sensor is configured to sense the type of tissue engaged with at least two of the plurality of mutually parallel cutting instruments. This arrangement advantageously utilizes the two cutting instruments to provide a path through the tissue, for example as two electrodes that contact across the tissue between the cutting instruments for electrical tissue measurements, or similarly provide an optical aperture / collector for optical tissue measurements. Even more broadly, in some embodiments, a sensor can include at least one of a plurality of mutually parallel cutting instruments 14, 16, 18, wherein the sensor is configured to sense the type of tissue engaged with the cutting instrument. For example, two electrodes for electrical tissue measurement can be integrated into a single cutting element, or an optical aperture and collector can be integrated into a single cutting element.

[0029] In addition to facilitating the advancement of the catheter 12 through the clot C, the sub-catheters 14, 16, 18 can also be used as components of a sensor for detecting the type of tissue engaged with the tip of the catheter 12. For example, the cutting instruments 14, 16, 18 can each include an optical fiber extending along its length to achieve optical measurement, and / or can be made of a conductive material (e.g., metal) to achieve electrical measurement. In a specific example, the measurement can include electrical impedance measurement. The cutting instruments 14, 16, 18 are connected to a motor 22 that is operably connected to periodically advance each of the cutting instruments 14, 16, 18 through the catheter 12 and into the clot C. For example, the motor 22 can drive a cam mechanism to which the proximal ends of the cutting instruments 14, 16, 18 are fixed. When the cam rotates, it continuously pushes each successive cutting instrument forward and then withdraws it. The cutting instruments 14, 16, 18 are also connected to an electronic processing device 24 (such as a workstation computer, a tablet computer, or more generally a computer) via a wire 26 to implement a tissue sensor (not shown).

[0030] In an electrical sensing embodiment, the electronic processing device 24 is operatively connected to measure an AC electrical characteristic (e.g., impedance) as a function of the frequency of an electrical current applied between a pair of cutting instruments 14, 16, 18 or between one of the cutting instruments and an electrical ground, a counter electrode, or another electrical reference (not shown). The resulting impedance spectrum is then used as a signature of the material disposed between the pair of cutting instruments, thereby enabling, for example, accurate determination of whether the tissue is clot material, vessel wall material, or blood.

[0031] In some embodiments, the motor 22 is also operably connected to the electronic processing device 24 via a wire 28 , and the electronic processing device 24 is configured to control the motor 22 to perform advancement of the cutting instrument 14 , 16 , 18 .

[0032] The electronic processing device 24 includes an electronic processor 30 (e.g., a microprocessor), optionally at least one user input device 32 (e.g., a mouse, keyboard, trackball, etc.), and a display device 34 (e.g., an LCD display, a plasma display, a cathode ray tube display, etc.) for displaying electrical or optical tissue measurements.

[0033] The electronic processor 30 is operatively connected to one or more non-transitory storage media 36. By way of non-limiting illustrative example, the non-transitory storage media 36 may include one or more of the following: a magnetic disk or other magnetic storage medium; a solid-state drive, a flash drive, or other electronic memory; an optical disk or other optical storage device; various combinations thereof, etc. It should be understood that any reference herein to one or more non-transitory media 36 should be broadly interpreted to encompass a single medium or multiple media of the same or different types. Similarly, the electronic processor 30 may be embodied as a single electronic processor or as two or more electronic processors. The non-transitory storage media 36 stores instructions that are executable by at least one electronic processor 30.

[0034] exist Figure 1 In the embodiment of the present invention, the cutting instruments 14, 16, 18 take the form of sub-conduits 14, 16, 18, each of which extends along the length of the catheter 12 so that their distal ends are disposed at the distal end of the catheter 12. This design enables the motor 22 that operates the cutting instruments 14, 16, 18 to be located at the proximal end of the catheter 12 outside the patient.

[0035] Figure 2 Another embodiment of the vascular treatment device 10 is shown in which the cutting instruments 14 , 16 , 18 are not sub-catheters, but are located only at the distal end of the catheter 12 . Figure 2 Examples and Figure 1 The embodiment of is configured similarly. However, here, the cutting instruments 14, 16, 18 are only provided at the distal end of the catheter 12 and do not take the form of a sub-catheter that extends the length of the catheter 12. In this embodiment, in order to enable the cutting instruments 14, 16, 18 to be moved back and forth, a cam mechanism or other drive mechanism 22D is positioned at the distal end of the catheter 12 to drive the reciprocating motion of the cutting instruments 14, 16, 18. A coupling 23 connects the drive mechanism 22D located at the distal end to a power source located at the proximal end of the catheter 12 outside the patient. In one approach, the drive mechanism 22D includes an electric motor, in which case the coupling 23 is appropriately a pair of electrical conductors that deliver power to the motor. In another approach, the motor is located at the proximal end of the catheter 12, and the coupling 23 is a mechanical coupling, such as a wire with high torsional resistance that delivers rotational force from the motor to the drive mechanism 22D. If electrical (e.g., impedance) spectrum measurements are to be performed, the coupling element 23 may further include wires connected to the respective cutting instruments 14, 16, 18 to enable connection to an impedance meter of the electronic processing device 24. Conversely, if optical spectrum measurements are to be performed, the coupling element 23 may further include optical fibers connected to the respective cutting instruments 14, 16, 18 to enable transmission of optical signals to and from the cutting instruments 14, 16, 18.

[0036] At least one electronic processor 30 is configured as described above to perform the block traversal method or process 100. The non-transitory storage medium 36 stores instructions that are readable and executable by the at least one electronic processor 30 to perform the disclosed operations, including performing the block traversal method or process 100. In some examples, the method 100 can be performed at least in part by cloud processing.

[0037] refer to Figure 3 , and continue to refer to Figure 1 (Although method 100 is applicable to Figure 2 ), an illustrative embodiment of an occlusion traversal method 100 is diagrammatically shown as a flow chart. To begin the method 100, a catheter 12 is inserted into a blood vessel V and adjacent to a clot C.

[0038] At operation 102, an electrical spectrum measurement is performed on at least one of the cutting instruments 14, 16, 18. In some examples, the electrical spectrum measurement can be an impedance measurement of the cutting instrument(s) 14, 16, 18. The output is an impedance spectrum or portion of an impedance spectrum, i.e., impedance as a function of AC frequency. In another embodiment, operation 102 can be an optical spectrum measurement that produces an optical spectrum. In another embodiment, the impedance can be measured at a certain frequency (or only a few individual frequencies), and the tissue determination can be performed based on these measurements.

[0039] At operation 104, based on the electrical (or optical) spectral measurements, the type of tissue engaged with the at least one cutting instrument 14, 16, 18 is determined. For example, the electrical (or optical) spectral measurements of the at least one cutting instrument 14, 16, 18 engaged with a clot C will differ from the electrical spectral measurements of the at least one cutting instrument 14, 16, 18 engaged with healthy tissue (i.e., a blood vessel V).

[0040] At operation 106 , the number of the plurality of cutting instruments 14 , 16 , 18 engaged with the clot C is determined based on the determined type of tissue. For example, electrical spectrum measurements may determine that two of the cutting instruments 14 , 16 , 18 are engaged with the clot C and another of the cutting instruments 14 , 16 , 18 is not engaged with the clot C.

[0041] At operation 108, the path of the catheter 12 relative to the clot C can be controlled based on the determined type of tissue engaged by the cutting instrument(s) 14, 16, 18. Using the same example, the path of the catheter 12 can be controlled by the motor 22 so that a cutting instrument 14, 16, 18 that is not engaged with the clot C can then be engaged with the clot C. Advantageously, the use of at least three cutting instruments 14, 16, 18 facilitates such manipulation of the penetration. For example, if one cutting instrument reciprocates more frequently than the other two, this can tilt the direction of the penetration.

[0042] The present disclosure has been described with reference to preferred embodiments. Modifications and alterations may occur to others after reading and understanding the foregoing detailed description. It is intended that the exemplary embodiments be interpreted as including all such modifications and alterations as long as they fall within the scope of the appended claims or their equivalents.

Claims

1. An intravascular treatment device (10), comprising: catheter (12); as well as A plurality of mutually parallel cutting instruments (14, 16, 18) are disposed at least at the distal end of the catheter, each cutting instrument being configured to engage a portion of a clot disposed in a blood vessel into which the catheter is advanced, each cutting instrument being independently advanceable into the clot.

2. The intravascular treatment device (10) according to claim 1, wherein The plurality of cutting instruments (14, 16, 18) each include serrations configured to engage portions of the clot.

3. The intravascular treatment device (10) according to any one of claims 1 and 2, wherein: The plurality of cutting instruments (14, 16, 18) each include an optical fiber.

4. The intravascular treatment device (10) according to any one of claims 1 to 3, wherein: The plurality of cutting instruments (14, 16, 18) are all made of conductive material.

5. The intravascular treatment device (10) according to any one of claims 1 to 4, further comprising at least one electronic processor (30) operatively connected to measure electrical characteristics between a pair of the cutting instruments (14, 16, 18) or between one of the cutting instruments and an electrical reference, the electronic processor being programmed to: performing electrical spectrum measurements on at least one of the cutting instruments (14, 16, 18); and A type of tissue engaged by the at least one cutting instrument is determined based on the electrical spectrum measurements.

6. The intravascular treatment device (10) according to claim 5, wherein: The at least one electronic processor (30) is programmed to: A number of the plurality of cutting instruments (14, 16, 18) to engage the clot is determined based on the determined type of tissue.

7. The intravascular treatment device (10) according to any one of claims 5 and 6, wherein: The at least one electronic processor (30) is programmed to: The path of the catheter (12) relative to the clot is controlled based on the determined type of tissue engaged by the at least one cutting instrument (14, 16, 18).

8. The intravascular treatment device (10) according to any one of claims 5 to 7, wherein: The electrical spectrum measurement includes impedance measurement.

9. The intravascular treatment device (10) according to claim 1, further comprising: A motor (22) is operatively connected to cyclically sequentially advance each of the plurality of cutting instruments (14, 16, 18).

10. The intravascular treatment device (10) according to any one of claims 1 to 9, wherein: The plurality of mutually parallel cutting instruments (14, 16, 18) includes at least three mutually parallel cutting instruments.

11. The intravascular treatment device (10) according to any one of claims 1 to 9, wherein: The plurality of mutually parallel cutting instruments (14, 16, 18) include a plurality of mutually parallel sub-catheters, each sub-catheter extending along the length of the catheter and having a distal end configured to engage the portion of the clot disposed in the blood vessel into which the catheter is advanced.

12. The intravascular treatment device (10) according to claim 1, further comprising: A sensor is included with at least one cutting instrument of the plurality of mutually parallel cutting instruments (14, 16, 18), the sensor being configured to sense a type of tissue engaged by the at least one cutting instrument of the plurality of mutually parallel cutting instruments.

13. An intravascular treatment device (10), comprising: A flexible conduit (12) comprising at least three mutually parallel flexible sub-conduits (14, 16, 18); wherein each daughter catheter has a tip configured to engage a portion of a blood clot; and Each sub-conduit is capable of moving independently relative to the other sub-conduits in the at least three mutually parallel flexible sub-conduits.

14. The intravascular treatment device (10) according to claim 13, wherein: The tip of each sub-conduit (14, 16, 18) has serrations on an outer surface of the tip.

15. The intravascular treatment device (10) according to claim 13, wherein At least two sub-conduits (14, 16, 18) include optical fibers extending through the at least two sub-conduits and having optical coupling holes at the tips of the at least two sub-conduits.

16. The intravascular treatment device (10) according to claim 13, wherein The sub-conduits (14, 16, 18) include an electrically conductive material.

17. A block crossing method (100), comprising: performing electrical spectrum measurements on at least one of the cutting instruments (14, 16, 18) disposed at least at the distal end of a catheter (12) to engage a portion of a clot disposed in a blood vessel into which the catheter is advanced; and A type of tissue engaged by the at least one cutting instrument is determined based on the electrical spectrum measurements.

18. The method (100) of claim 17, further comprising: A number of the plurality of cutting instruments (14, 16, 18) to engage the clot is determined based on the determined type of tissue.

19. The method (100) according to any one of claims 17 and 18, wherein: The at least one electronic processor (30) is programmed to: The path of the catheter (12) relative to the clot is controlled based on the determined type of tissue engaged by the at least one cutting instrument (14, 16, 18).

20. The method (100) according to any one of claims 17-19, wherein: The electrical spectrum measurement includes impedance measurement.

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