DELIVERY CATHETER DEVICE AND SYSTEM FOR ACCESSING THE INTRACRANIAL VASCULATURE

Abstract

A delivery catheter device for accessing intracranial vasculature are disclosed. The delivery catheter comprises an elongated tubular body having a lumen, a proximal section (10), a distal section (30) and at least three longitudinally arranged transition sections (20) disposed between the proximal section (10) and the distal section (30), wherein the distal section (30) is the most flexible section and the proximal section (10) is the stiffest section. A first transition section (21, 21B) has a stiffness less or equal than a stiffness of the proximal section (10), a second transition section (22) is disposed distal to the first transition section (21, 21B) and has a stiffness greater or equal than the stiffness of the first transition section (21, 21B), and a third transition section (23, 23A) is disposed distal to the second transition section (22) and has a stiffness less than the stiffness of the second transition section (22).

Claims

1. A delivery catheter device for accessing intracranial vasculature and for delivering a movable medical device beyond a carotid syphon, comprising: an elongated tubular body having a lumen, a proximal section, a distal section and at least three longitudinally arranged transition sections disposed between the proximal section and the distal section, the distal section being the most flexible section of the elongated tubular body, and the proximal section being the stiffest section of the elongated tubular body; wherein a first transition section of the longitudinally arranged transition sections has a stiffness less than a stiffness of the proximal section, a second transition section of the longitudinally arranged transition sections is disposed distal to the first transition section and has a stiffness greater than the stiffness of the first transition section, and a third transition section of the longitudinally arranged transition sections is disposed distal to the second transition section and has a stiffness less than the stiffness of the second transition section, so that the proximal section and the transition sections of the delivery catheter are configured to enable the distal section to be advanced beyond the carotid syphon when a distally directed force on the proximal section is applied.

2. The delivery catheter of claim 1, wherein the longitudinally arranged transition sections further comprise: a fourth transition section disposed distal to the third transition section and having a stiffness less than the stiffness of the third transition section and greater than the stiffness of the distal section, and a fifth transition section disposed proximal to the first transition section and having a stiffness less than the stiffness of the proximal section and greater than the stiffness of the first transition section.

3. The delivery catheter device of claim 1, wherein the distal section has a length in a range of 80-170 mm and a durometer in a range of 25-55 D.

4. The delivery catheter device of claim 3, wherein the third transition section has a length in a range of 40-160 mm and a durometer in a range of 40-60 D.

5. The delivery catheter device of claim 1, wherein the distal section has a durometer up to 35 D.

6. The delivery catheter device of claim 1, wherein the distal section and the third transition section have a durometer up to 55 D.

7. The delivery catheter device of claim 1, wherein the proximal section is made of a polyamide 12 material, the longitudinally arranged transition sections are made of a polyether block amide material and the distal section is made of a thermoplastic polyurethane material.

8. The delivery catheter device of claim 2, wherein the proximal section has a durometer of 70 D, the distal section has a durometer of 29 D, and the five transition sections have durometers of 72 D, 55 D, 72 D, 55 D, and 40 D, respectively, starting from the transition section adjacent to the proximal section.

9. The delivery catheter device of claim 1, wherein the proximal section has a durometer in a range between 70-74 D, the distal section has a durometer in a range between 25-30 D, the third transition section next to the distal section has a durometer in a range between 40-60 D, the second transition section has a durometer in a range between 55-74 D, and the first transition section next to the proximal section has a durometer in a range between 55-74 D.

10. The delivery catheter device of claim 1, wherein the elongated tubular body has an outer diameter in a range between 2.0-2.18 mm and an inner diameter in a range between 1.65-1.85 mm.

11. The delivery catheter device of claim 1, wherein the elongated tubular body further comprises a reinforcing coil, wherein a section of the reinforcing coil in the transition sections has a stiffness that is different than a stiffness of a section of the reinforcing coil in the proximal section and a stiffness of a section of the reinforcing coil in the distal section.

12. The delivery catheter of claim 1, wherein the movable medical device is disposed within the distal section, the proximal section and the transition sections of the delivery catheter being configured to enable the distal section to be advanced beyond the carotid syphon when a distally directed force on the proximal section is applied.

13. The delivery catheter device of claim 1, wherein it is adapted to hold the movable medical device within the elongated tubular body and to place said movable medical device in an intracranial blood vessel to remove a thrombus, wherein the movable medical device is adapted to change its shape from a collapsed position within the elongated tubular body to an extended and expanded position at an opening of the distal section to remove said thrombus, such that the stiffness of a portion of the delivery catheter device is altered by the movable medical device as it moves through that portion of the elongated tubular body.

14. The delivery catheter device of claim 1, further comprising a radiopaque marker at the distal section of the elongated tubular body to allow viewing a position of the delivery catheter device within the intracranial blood vessel under fluoroscopy.

15. A system for accessing the intracranial vasculature and for delivering a movable medical device beyond a carotid syphon, comprising: a movable medical device; a delivery catheter device comprising an elongated tubular body having a lumen, a proximal section, a distal section and at least three longitudinally arranged transition sections disposed between the proximal section and the distal section, wherein the distal section is the most flexible section of the elongated tubular body, wherein the proximal section is the stiffest section of the elongated tubular body; the delivery catheter is adapted to hold said movable medical device within the elongated tubular body and to place it in an intracranial blood vessel to remove a thrombus; the movable medical device is adapted to change its shape from a collapsed position within the elongated tubular body to an extended and expanded position at an opening of the distal section to remove said thrombus; wherein a first transition section of the longitudinally arranged transition sections has a stiffness less than a stiffness of the proximal section, a second transition section of the longitudinally arranged transition sections is disposed distal to the first transition section and has a stiffness greater than the stiffness of the first transition section, and a third transition section of the longitudinally arranged transition sections is disposed distal to the second transition section and has a stiffness less than the stiffness of the second transition section, and so that the proximal section and the transition sections of the delivery catheter are configured to enable the distal section to be advanced beyond the carotid syphon when a distally directed force on the proximal section is applied when the movable medical device is disposed within the distal section.

16. The system of claim 15, wherein the longitudinally arranged transition sections further comprise: a fourth transition section disposed distal to the third transition section and having a stiffness less than the stiffness of the third transition section and greater than the stiffness of the distal section, and a fifth transition section disposed proximal to the first transition section and having a stiffness less than the stiffness of the proximal section and greater than the stiffness of the first transition section.

17. The system of claim 15, wherein the distal section has a length in a range of 80-170 mm and a durometer in a range of 25-55 D.

18. The system of claim 17, wherein the third transition section has a length in a range of 40-160 mm and a durometer in a range of 40-60 D.

19. The system of claim 15, wherein the distal section has a durometer up to 35 D.

20. The system of claim 15, wherein the distal section and the third transition section have a durometer up to 55 D.

21. The system of claim 15, wherein the proximal section is made of a polyamide 12 material, the longitudinally arranged transition sections are made of a polyether block amide material and the distal section is made of a thermoplastic polyurethane material.

22. The system of claim 15, wherein the elongated tubular body further comprises a reinforcing coil, wherein a section of the reinforcing coil in the transition sections has a stiffness that is different than a stiffness of a section of the reinforcing coil in the proximal section and a stiffness of a section of the reinforcing coil in the distal section.

23. The system of claim 15, wherein the movable medical device is configured to alter the stiffness of a portion of the delivery catheter device as it moves through that portion of the elongated tubular body.

24. The system of claim 15, wherein the movable medical device comprises a segment formed by a mesh of at least two sets of helicoidal filaments turning respectively in opposite directions and being intertwined, wherein the mesh comprises two distinct tubular sections, a first section and a second section, wherein the second section, adjacent to the first section, provides a reduction of diameter, and wherein said mesh of the first section has a variable density of the helicoidal filaments configured to provide radial forces higher than in the second section such that the first section becomes appositioned against an inner wall of the intracranial blood vessel.

25. The system of claim 15, further comprising a radiopaque marker at the distal section of the elongated tubular body and/or in the mesh of the movable medical device to allow viewing a position of the delivery catheter device within the intracranial blood vessel under fluoroscopy and/or to allow viewing when a distal section of the movable medical device is aligned with the distal section of the elongated tubular body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] FIG. 1 is a view of a delivery catheter according to an embodiment of the present invention.

[0060] FIG. 2 is a view of a delivery catheter according to another embodiment of the present invention.

[0061] FIG. 3 illustrates a movable medical device to be hold within a delivery catheter according to embodiments of the present invention.

[0062] FIG. 4A illustrates an in-vitro 3D model showing the neurovascular anatomy.

[0063] FIG. 4B illustrates the neurovascular anatomy and the length ranges of each segment.

[0064] FIG. 5 illustrates the set-up scheme of the 3-point bending experiment done in Example 2.

[0065] FIG. 6A illustrates the flexibility profile (i.e. Peak Force [N] performed in 19 points along the catheter's length taking the distal end as the reference point) obtained for different catheters: ANA Delivery Catheter from Anaconda Biomed (ANA DC alone), ACE 68 from Penumbra and Sofia Plus from Terumo.

[0066] FIG. 6B illustrates the flexibility profile (i.e. Peak Force [N] performed in 19 points along the catheter's length taking the distal end as reference point) obtained for the ANA system in three different configurations: ANA Delivery Catheter alone (ANA DC alone), ANA Delivery Catheter in combination with the Funnel Catheter deployed (ANA DC+FC deployed), and ANA Delivery Catheter in combination with the Funnel Catheter with its distal tip at 5 mm of the distal tip of the Delivery Catheter (ANA DC+FC 5 mm from tip).

DETAILED DESCRIPTION OF THE INVENTION AND OF PARTICULAR EMBODIMENTS

[0067] The delivery catheter of the invention is configured to reach a brain target location within an intracranial blood vessel. According to FIG. 4B, the delivery catheter is configured to be advanced beyond the carotid syphon reaching a cerebral artery (e.g. middle posterior or anterior cerebral artery). In an embodiment, the brain target location is a cerebral artery (e.g. located at least 30-50 mm distal to the carotid syphon), the distal section is disposed beyond the carotid syphon (e.g. located 30-50 mm distal to the basilar artery) and the transition section is disposed beyond the basilar artery (e.g at least 50-100 mm distal to the proximal-middle portion of the carotid artery).

[0068] Referring to FIGS. 1 and 2, these figures show different embodiments of the proposed delivery catheter device for accessing the intracranial vasculature. The delivery catheter device illustrated in FIGS. 1 and 2 has an elongated tubular body having a lumen, a proximal section 10, a distal section 30 and a set of longitudinally arranged transition sections 20 disposed between the proximal section 10 and the distal section 30.

[0069] In either of the previous embodiments, the proximal section 10 is the stiffest section of the elongated body for robust pushability of the delivery catheter, and the distal section is the most flexible section of the elongated tubular body to overcome tortuous paths in the vessels (i.e. to enhance navigation of the delivery catheter). The longitudinally arranged transition sections 20 include a first transition section that is less stiff than, or equally stiff to, the proximal section 10, a second transition section distal to the first transition section that is more stiff than, or equally stiff to, the first transition section, and a third transition section distal to the second transition section that is less stiff than the second transition section. The transition sections 20 are designed to enhance the ability of the delivery catheter to advance through tortuosities in the vessels. The longitudinal position and the length of each transition section are chosen to address the characteristics of the vasculature through which the delivery catheter will be advanced. For example, the third transition section can be placed at a longitudinal location that will be just proximal to a tortuous section of the vasculature (e.g., the carotid syphon 405, see FIG. 4A) to provide pushability as the flexible distal section 30 of the catheter passes through the tortuous vasculature, for example to reach the M1 segment 406 of the brain anatomy.

[0070] In some embodiments, the transition sections 20 have different durometers than the proximal and distal sections (e.g., by employing different materials) to avoid kinking/break points. For example, the proximal section 10 can be made of a polyamide 12 material such as Grilamid® thermoplastic, the longitudinally arranged transition sections 20 can be made of a polyether block amide material (e.g. PEBAX®) and the distal section 30 can be made of a thermoplastic polyurethane material such as Pellethane 80A. The durometer of the Grilamid material can range from 66 to 77 depending on its specific composition/type. In some embodiments, Grilamid L25 or L25H is used. In other embodiments, Grilamid TR90 or TR55 is used. In yet other embodiments, Grilamid LV is used. By using different materials for the different transition sections 20, each of the transition sections 20 can have a different stiffness without significantly altering the thickness of the catheter wall between adjacent sections.

[0071] The number and flexibility characteristics of transition sections 20 can be chosen to meet the clinical need. In the embodiment of FIG. 1, for example, the delivery catheter comprises five longitudinally arranged transition sections, referred in the figure as 21A, 21B, 22, 23A, and 23B. In this embodiment, the relative stiffness of each of the transition sections is affected by the hardness of the materials used in the transition sections. Thus, the middle transition section 22 has a higher durometer than its adjacent, previous 21B and next 23A, transition sections. In the embodiment of FIG. 2, the delivery catheter comprises three longitudinally arranged transition sections, referred to 21, 22 and 23. The middle transition section 22 has a higher durometer than its adjacent, previous 21, and next 23, transition sections. That is, the middle transition section is precisely designed to be stiffer than its preceding and following transition sections to enable the catheter to transmit a distally directed pushing force while navigating through tortuous vessels and to thereby enhance longitudinal force transmission from proximal section 10 to distal section 30 without elongation or tension accumulation. In this way, all the force applied at the proximal section 10 is transferred into movement at the distal section 30 despite the tortuosity of the vessels between proximal section 10 and distal section 30.

[0072] More in particular, in the embodiment of FIG. 1, the transition section (or fifth transition section) 21A is disposed distal to the proximal section 10 and is less stiff than, or equally stiff to, the proximal section 10; the transition section (or first transition section) 21B is disposed distal to the transition section 21A and is less stiff than, or equally stiff to, the transition section 21A; the transition section (or second transition section) 22 is disposed distal to the transition section 21B and is more stiff than the transition section 21B; the transition section (or third transition section) 23A is disposed distal to the transition section 22 and is less stiff than the transition section 22; the transition section (or fourth transition section) 23B is disposed distal to the transition section 23A and is less stiff than the transition section 23A and more stiff than the distal section 30. This more complex transition structure may enable the catheter to more effectively navigate through tortuous vessels without elongation or tension accumulation.

[0073] In some embodiments of FIG. 1, the different durometers, materials and lengths of the different sections of the tubular elongated body can be the following:

TABLE-US-00001 TABLE 1 SECTION MATERIAL DUROMETER LENGTH 10 Extrusion- GRILAMID 70 D 392 mm 21A Extrusion- PEBAX 72 D 450 mm 21B Extrusion- PEBAX 55 D 110 mm 22 Extrusion- PEBAX 72 D 30 mm 23A Extrusion- PEBAX 55 D 50 mm 23B Extrusion- PEBAX 40 D 60 mm 30 Extrusion- Pellethane 80A 29 D 150 mm

TABLE-US-00002 TABLE 2 SECTION MATERIAL DUROMETER LENGTH 10 Extrusion- GRILAMID 70 D 450 mm 21A Extrusion- PEBAX 70 D 450 mm 21B Extrusion- PEBAX 70 D 110 mm 22 Extrusion- PEBAX 72 D 15 mm 23A Extrusion- PEBAX 55 D 50 mm 23B Extrusion- PEBAX 40 D 50 mm 30 Extrusion- Pellethane 80A 29 D 100 mm

TABLE-US-00003 TABLE 3 SECTION MATERIAL DUROMETER LENGTH 10 Extrusion- GRILAMID 70-74 D 350-600 mm 21A Extrusion- PEBAX 70-72 D 50-600 mm 21B Extrusion- PEBAX 55-72 D 22 Extrusion- PEBAX 55-72 D 20-200 mm 23A Extrusion- PEBAX 55-72 D 30-70 mm 23B Extrusion- PEBAX 40-55 D 40-80 mm 30 Extrusion- Pellethane 80A 25-30 D 80-170 mm

[0074] In an embodiment, the proximal section 10 has a durometer between 70-74 D and the distal section 30 has a durometer between 25-30 D. In the embodiment of FIG. 1, the transition section 21A has a durometer between 70-72 D, but lower or equal than the durometer of the proximal section 10; the transition section 21B has a durometer between 55-72 D, but lower or equal than the durometer of the transition section 21A; the transition section 22 has a durometer between 55-72 D, more particularly between 60-72 D, but higher than the durometer of the transition section 21B; the transition section 23A has a durometer between 55-72 D, but lower than the durometer of the transition section 22; the transition section 23B has a durometer between 40-55 D, but lower than the durometer of the transition section 23A.

[0075] In any of the above embodiments, the elongated tubular body can have a length in a range between 900-1500 mm, particularly 1000-1400 mm, for example 1320 mm or 1350 mm.

[0076] In an embodiment, the length of the proximal section 10 depends on the overall length of the delivery catheter. In another embodiment, the length of the proximal section 10 ranges between 350-600 mm, for example 450 mm.

[0077] In an embodiment, the length of the distal section 30 ranges between 80-170 mm, for example 100 mm or 150 mm.

[0078] In an embodiment, the length of the transition section 21B and the length of the transition section 21A depend on the overall length of the delivery catheter. In another embodiment, the length of the transition section 21B and the length of the transition section 21A sum up between 50-600 mm, for example, the length of the transition section 21A and the transition section 21B are 450 mm and 110 mm, respectively.

[0079] In an embodiment, the length of the transition section 22 ranges between 20-200 mm, particularly 20-60 mm or 60-200 mm.

[0080] In an embodiment, the length of the transition section 23A ranges between 40-80 mm, particularly 40-60 mm or 60-80 mm.

[0081] In an embodiment, the length of the transition section 23B ranges between 30-70 mm, particularly 30-50 mm or 50-70 mm.

[0082] In one embodiment, the different sections of the delivery catheter have a stiffness as shown in Table 4, wherein the stiffness is measured in terms of peak force [N] as described in Example 1.

TABLE-US-00004 TABLE 4 FORCE LENGTH SECTION FORCE RANGE LENGTH RANGE 10 1.92N 1.46-2.22N 392 mm 350-600 mm 21A 1.43N 1.04-1.75N 450 mm 50-600 mm 21B 0.66N 0.63-1.04N 110 mm 22 0.66N 0.63-0.69N 30 mm 20-200 mm 23A 0.63N 0.39-0.69N 50 mm 30-70 mm 23B 0.39N 0.31-0.47N 60 mm 40-80 mm 30 0.27N 0.23-0.31N 150 mm 80-170 mm

[0083] Referring back to FIG. 2, the first transition section 21 is less stiff than, or equally stiff to, the proximal section 10; the second transition section 22 is disposed distal to the first transition section 21 and particularly is more stiff than, or equally stiff to, the first transition section 21; and the third transition section 23 is disposed distal to the second transition section 22 and is less stiff than the second transition section 22.

[0084] In some embodiments of FIG. 2, the different durometers, materials and lengths of the different sections of the tubular elongated body can be the following: Table 5:

TABLE-US-00005 TABLE 5 SECTION MATERIAL DUROMETER LENGTH 10 Extrusion- GRILAMID 70-74 D 392 mm 21 Extrusion- PEBAX 55-72 D 560 mm 22 Extrusion- PEBAX 60-72 D 30 mm 23 Extrusion- PEBAX 40-55 D 110 nm 30 Extrusion- Pellethane 80A 25-30 D 150 mm

TABLE-US-00006 TABLE 6 SECTION MATERIAL DUROMETER LENGTH 10 Extrusion- GRILAMID 70-74 D Depending on the overall length of the catheter 21 Extrusion- PEBAX 55-74 D 50-600 mm 22 Extrusion- PEBAX 55-74 D 15-200 mm 23 Extrusion- PEBAX 40-60 D 40-160 nm 30 Extrusion- Pellethane 80A 25-55 D 80-170 mm

TABLE-US-00007 TABLE 7 SECTION MATERIAL DUROMETER LENGTH 10 Extrusion- GRILAMID 70-74 D Depending on the overall length of the catheter 21 Extrusion- PEBAX 55-72 D 110-560 mm 22 Extrusion- PEBAX 60-72 D 15-50 mm 23 Extrusion- PEBAX 40-60 D 100-150 nm 30 Extrusion- Pellethane 80A 25-55 D 100-150 mm

TABLE-US-00008 TABLE 8 SECTION MATERIAL DUROMETER LENGTH 10 Extrusion- GRILAMID 70 D-74 D 350-600 mm 21 Extrusion- PEBAX 55 D-74 D 50-200 mm 22 Extrusion- PEBAX 55 D-74 D 20-200 mm 23 Extrusion- PEBAX 40-60 D 40-160 mm 30 Extrusion- Pellethane 80A 25-30 D 80-170 mm

[0085] In an embodiment, the proximal section 10 has a durometer between 70-740 and the distal section 30 has a durometer between 25-550. In the embodiment of FIG. 2, the first transition section 21 has a durometer between 55-740, but lower or equal than the durometer of the proximal section 10; the second transition section 22 has a durometer between 55-740, but higher than the durometer of the first transition section 21; the third transition section 23 has a durometer between 40-600, but lower than the durometer of the second transition section 22.

[0086] In an embodiment, the length of the proximal section 10 depends on the overall length of the delivery catheter. In another embodiment, the length of the proximal section 10 ranges between 350-600 mm, for example 392 mm.

[0087] In an embodiment, the length of the distal section 30 ranges between 80-170 mm, particularly 100-150 mm, for example 100 or 150 mm.

[0088] In an embodiment, the length of the first transition section 21 depends on the overall length of the delivery catheter. In another embodiment, the length of the first transition section 21 ranges between 50-600 mm, particularly 110-560 mm, for example 110 or 560 mm.

[0089] In an embodiment, the length of the second transition section 22 ranges between 15-200 mm, particularly 15-60 mm or 60-200 mm, for example 15 or 30 mm.

[0090] In an embodiment, the length of the third transition section 23 ranges between 40-160 mm, particularly 50-150 mm, for example 50, 60 or 110 mm.

[0091] In an embodiment, the elongated tubular body comprises two longitudinal layers, an inner layer made of PTFE and an outer layer made of PEBAX®. In some embodiments, the elongated tubular body further includes an intermediate layer made of PEBAX® disposed between the inner and outer layers.

[0092] The elongated tubular body can also comprise a soft-tip zone disposed at the most distal part of the distal section 30. The soft-tip zone particularly has a length of 2 mm and a durometer of 25-30, particularly 29.

[0093] The elongated tubular body can also include a reinforcing coil. The reinforcing coil can extend the full length of the elongated tubular body (disposed in the soft-tip zone) or can extend until the distal section 30 only. The reinforcing coil can be disposed between the outer layer and the inner layer or between the outer layer and the intermediate layer.

[0094] The reinforcing coil in particular comprises a stainless-steel material. This coil structure underneath the jacket material of the tubular body is designed also to enhance the longitudinal force transmission. The coil structure varies from a small pitch for a higher stiffness at the proximal section 10 to a bigger pitch for a better flexibility at the distal section 30. Also, the coil structure in the second transition section 22 is different to its adjacent transition sections.

[0095] In a particular embodiment, the reinforcing coil comprises a 0.010″ pitch at the proximal section 10, a 0.012″ pitch at the middle transition section 22 and a 0.015″ pitch at the distal section 30.

[0096] The elongated tubular body can have a diameter on the order of 4 to 6 French. In a particular embodiment the delivery catheter is a 6-French diameter device.

[0097] By way of non-limiting example, the elongated tubular body can have an outer diameter between 0.078″ and 0.085″ (i.e., 2.0-2.18 mm), particularly 0.083″ (i.e., 2.11 mm). This diameter is defined by a guiding catheter. The requirement set is that the delivery catheter needs to fit the guiding catheter with a minimum ID of 0.088″ (i.e., 2.2 mm). If the diameter of the delivery catheter changes, other parameters (e.g., material/stainless-steel structure) can be readjusted to maintain the flexibility/pushability properties achieved with current design. In some embodiments, the inner diameter of the elongated tubular body is limited by an outer diameter of an aspiration catheter which will be disposed within the delivery catheter. A minimum clearance between them is needed (0.05 mm). In another embodiment, the elongated tubular body can have an inner diameter between 0.064″-0.073″ (i.e., 1.65-1.85 mm), particularly 0.072″ (i.e., 1.82 mm). In another embodiment, the thickness of the elongated tubular body is 0.011″ (i.e., 0.28 mm).

TABLE-US-00009 TABLE 9 Range Real (nominal) Delivery OD [mm]  2.0-2.18 2.11 catheter ID [mm] 1.65-1.85 1.82

[0098] Although the design of the proposed delivery catheter is optimized to access the brain, in particular through the carotid syphon 405, the delivery catheter can be equally used for other applications. In the alternative applications other than the brain the cited diameters can be equal or higher. For example, for the peripheral circulatory system, the diameter can be of 9F (French)=3 mm. In other applications, for example for accessing renal arteries, gastric arteries, uterine arteries, etc. diameters of 6F=2 mm can be used.

[0099] The elongated tubular body can also include a coating, such as a hydrophilic coating. Different hydrophilic materials can be used for example: Polyvinylpyrrolidone, Polyacrylamide or combinations thereof, among others.

[0100] After placement of the delivery catheter at a desired location in a vessel of the patient's vasculature, a medical device can be moved through and out of the delivery catheter to that target location. While in the catheter as the catheter moves through the vasculature, the movable medical device can increase the stiffness of the catheter at the location of the medical device. In some embodiments, the movable medical device to be delivered by the delivery catheter has a collapsed delivery configuration, and it self-expands when moved out of the distal end of the delivery catheter into an expanded deployed configuration. While in the delivery configuration, the movable medical device exerts an outward radial force on the delivery catheter, which can add to the stiffness of the catheter at the location of the medical device.

[0101] FIG. 3 shows an example of a movable medical device that can be held/accommodated by the proposed delivery catheter. Therefore, in some embodiments of the invention, the system provided by the present invention includes both a delivery catheter and a movable medical device.

[0102] The illustrated movable medical device can change its shape from a collapsed position within the elongated tubular body to an extended and expanded position outside of an opening of the distal section 10 to remove a thrombus. In its collapsed delivery configuration, the movable medical device can apply a radially-outward force on the inner surface of the delivery catheter. Thus, the movable medical device can alter the stiffness of the delivery catheter device as it is advanced or retracted through the elongated tubular body. In one aspect of the method of this invention, the movable medical device can be advanced or retracted within the delivery catheter to alter the stiffness of a section of the delivery catheter. For example, the delivery catheter can be advanced through portions of the vasculature with the movable medical device disposed within the distal section of the delivery catheter. When the distal end of the delivery catheter reaches a more tortuous portion of the vasculature, the movable medical device can be retracted a short distance within the delivery catheter to increase the flexibility of the distal portion of the delivery catheter. The movable medical device can be advanced to the distal end of the delivery catheter after the distal end of the delivery catheter has gotten beyond the tortuous vasculature portion.

[0103] In particular, the movable medical device illustrated in FIG. 3 includes a segment 100 comprising a mesh 130 having two sets of helicoidal filaments turning respectively in opposite directions and being intertwined. The mesh 130 in an embodiment can follow a diamond-type structure or a regular structure. The density of the mesh 130 defines the elasticity of the segment 100. A mesh angle (p) with regard to a longitudinal direction can be variable.

[0104] The helicoidal filaments can be made of a metal (including metal alloys), polymers, a composite including Nitinol or Nitinol/Platinum, among other materials having suitable mechanical properties.

[0105] The mesh 130 defines two distinct tubular sections, a first section 200 and a second section 300. The second section 300 provides a reduction of diameter. The second section 300 in some embodiment can comprise two sub sections, a first sub section and a second sub section. The first sub-section (or portion of the second section 300 adjacent to the first section 200) is cone-shaped or funnel-shaped. Because of its shape, this sub-section has features enabling it to withstand the blood pressure without collapsing.

[0106] The mesh 130 of the first section 200 provides radial forces higher than in the second section 300, such that the first section 200 becomes appositioned against an inner wall of an intracranial blood vessel. The radial forces in first and second end portions of the first section 200 can be higher than in an intermediate portion thereof or the radial forces in the first section 200 can be uniformly distributed along its generatrix.

[0107] An end portion of the first section 200 comprises closed loops 230 facilitating the expansion of the segment 100 once it comes out of the delivery catheter. These closed loops 230 act as a spring or fixing point by limiting the movement between the helicoidal filaments and thus increasing the outward radial force.

[0108] The distal section 30 and/or the mesh 130 of the movable medical device can include a radiopaque marker. This allows knowing the delivery catheter's position under fluoroscopy and/or knowing when a distal section of the movable medical device is aligned with the distal section 30 of the elongated tubular body.

[0109] To deliver segment 100 through a delivery catheter of this invention (such as e.g., the delivery catheters illustrated in FIG. 1 and FIG. 2) to capture a thrombus in an intracranial blood vessel of the patient, the distal section of the delivery catheter can be inserted through an opening into the patient's femoral artery or brachial artery at an insertion site. Segment 100 can be disposed in a collapsed delivery configuration in the distal section 30 of the delivery catheter as the delivery catheter is advanced through the vasculature toward the target location in the intracranial blood vessel. The proximal section 10 of the delivery catheter provides pushability as the delivery catheter and segment 100 are advanced.

[0110] When the distal section 30 of the delivery catheter reaches a tortuous portion of a blood vessel, the segment 100 can be withdrawn proximally to decrease the stiffness of the distal section 30. Segment 100 can be advanced distally into the distal section 30 after the distal section 30 is advanced through the tortuous portion of the vessel.

[0111] In some vessels, the relative positions of the distal section 30 and the transition sections 20 of the delivery catheter are such that the stiffest transition section of the delivery catheter will be disposed just proximal to a tortuous section of a vessel (e.g., the carotid syphon 405) when the distal section 30 enters that tortuous section. The less stiff section of the delivery catheter proximal to the transition section provides continued flexibility to the transition section of the delivery catheter while the stiffest transition section provides pushability as the distal section of the delivery catheter is advanced through the tortuous section of the vessel.

[0112] When the distal section 30 of the delivery catheter reaches the target location in the intracranial vessel, segment 100 can be advanced out of an opening in the distal end of the delivery catheter to self-expand and capture the thrombus. Further details of the movable medical device illustrated in FIG. 3 and its use to capture an intracranial thrombus can be found in U.S. Provisional Application No. 62/760,786, filed Nov. 13, 2018 and International Patent Application WO2020079082A1, filed Nov. 13, 2019.

[0113] The embodiments described above are to be understood as a few illustrative examples of the present invention. It will be understood by those skilled in the art that various modifications, combinations and changes can be made to the embodiments without departing from the scope of the present invention. In particular, different part solutions in the different embodiments can be combined in other configurations, where technically possible.

[0114] Following, different examples of the performance of the proposed delivery catheter device are detailed. The examples and drawings are provided herein for illustrative purposes, and without intending to be limiting to the present invention.

Example 1: Flexibility Testing of Commercially Available Catheter Devices in Comparison with the ANA System

[0115] The anatomy of the brain presents a very irregular pathways where delivery catheters should navigate to allow the delivery of other coaxial catheters in order to withdrawn thrombus from a target brain location.

[0116] FIG. 4A illustrates an embodiment of a 3D in-vitro model of the brain; particularly the Jacobs 3.4 model, where the different segments forming the anatomy of the brain: cervical segment 402, petrous segment 403, cavernous segment 404, carotid syphon 405 and M1 segment 406, are shown. In FIG. 4A, the initial placement 401 of a guiding catheter is also shown.

[0117] To obtain a good navigability and pushability of the delivery catheters to reach a target location through the different segments 402-406, the delivery catheters must present different sections with specific stiffness and length, to overcome the tortuous and irregular segments 402-406 of the brain.

[0118] The delivery catheters need to be able to navigate until or beyond the carotid syphon 405 no matter where the location of other external coaxial devices (such as a Guide Catheter) are.

[0119] The ANA system manufactured by Anaconda Biomed consists of two coaxial catheters called the Delivery Catheter and the Funnel Catheter (according to FIGS. 1 and 3, respectively). These two catheters are used together to properly deploy a funnel structure near a clot. The deployment of this structure allows a local flow restriction near the clot area with the aim of proceeding to extract the clot with the aid of a stent retriever and a direct aspiration procedure by the Funnel Catheter.

[0120] The purpose of this experimental test was to measure the flexibility in different sections along the whole length of the Delivery Catheter of the ANA system and compare it against other commercially available neurovascular catheters, such as ACE68 (manufactured by Penumbra) and Sofia Plus (manufactured by Terumo). The Delivery Catheter of the ANA system (hereinafter ANA DC) was also evaluated in combination with the Funnel Catheter (hereinafter FC) manufactured by Anaconda Biomed in two different configurations: the ANA DC with the FC deployed (hereinafter as: ANA DC+FC deployed) or the ANA DC with the FC with the distal tip at 5 mm of the distal tip of the DC (hereinafter as: ANA DC+FC 5 mm).

[0121] The evaluation of the flexibility was quantified using the 3-point bending (3PB) method in order to provide quantitative insight into the final behavior regarding the navigability, trackability and deliverability of the catheters in a target site (e.g. enable the delivery of the Funnel Catheter).

[0122] Methods

[0123] At least 3 units of the following catheters were evaluated; ANA DC, ACE68, and Sofia Plus. ANA system was evaluated in three different configurations: ANA DC alone, ANA DC+FC (with deployed funnel), and ANA DC+FC (with the distal tip of the FC at 5 mm of the distal tip of the DC).

[0124] The 3PB evaluation was performed in 19 different testing points along the catheter's length. The testing points were defined taking the distal tip of the catheters as a reference (Point 0 cm). The points evaluated in the catheter were: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 80, 90, 100, 110, and 120 cm.

[0125] The 3PB apparatus (FIG. 5) consists of a means applying and accurately measuring loads and deflections to a specimen mounted in a 3PB bending fixture. The catheters were put over the fixture having two support points with a gauge length of 30 mm. The maximum force was recorded when a pusher element with 3.2 mm radius, pushed in the central portion of the specimen by 2 mm at a rate of 3 mm/min. This testing method is according the ASTM F2606-08.

[0126] Results

[0127] The results, as illustrated in FIG. 6A and FIG. 6B, show the flexibility profile obtained for the different catheters. Mainly, both the most proximal section (2.2-3.2 N) and the most distal section (0.3-0.5 N) of the ANA system in all the studied configurations are stiffer than other commercially available neurovascular catheters, which tend to have similar distal end (<0.1N) and proximal end (1.2-1.8 N) stiffness, making the main decrease from 45 to 20 cm from the distal tip. The additional distal stiffness compared with other commercially available devices, avoids the DC to be elongated due to the presence of the funnel in the distal section of the DC, maintaining the integrity of the catheter during the intervention.

[0128] Furthermore, with the ANA system (ANA DC alone, ANA DC+FC deployed and ANA DC+FC 5 mm) there is a transition near 30 cm from the distal tip from a stiffer section to a more flexible section that is intended to transmit the axial movement forces from the proximal to the distal section of the catheter, avoiding, at the same time, possible alterations in the structure of the ANA DC. This transition depends on the structural configuration of the ANA DC, which presents specific stiffness values generating a specific flexibility behavior. On the other hand, the ANA DC+FC (with deployed funnel) and ANA DC+FC (with the distal tip of the FC at 5 mm of the distal tip of the DC) configurations resulted slightly stiffer than the ANA DC stand alone.

[0129] Conclusions

[0130] 3PB tests showed differences in the flexibility profiles between the ANA DC and different commercially available neurovascular catheters.

[0131] The ANA system (ANA DC alone, ANA DC+FC deployed and ANA DC+FC 5 mm) has a higher stiffness in the distal end and in the proximal end compared to the commercially available neurovascular catheters. The higher stiffness of ANA system in the distal section allows the correct interaction functioning between the ANA DC and the FC, avoiding the elongation of the devices, which it seems not possible with the other commercially available neurovascular catheters (ACE68 and Sofia Plus). Moreover, the transition section present at near 30 cm from the distal tip is intended to correctly transmit axial forces from the proximal end to the distal end of the ANA DC and this improves the pushability and navigability of the ANA DC, which in conjunction with the FC can slightly change its stiffness to adjust the pushability depending on the segment 401-406 of the brain which is passing through.

[0132] In conclusion, all these aforementioned features allow the ANA system to reach the brain target site passing through the tortuous vascularity without altering its integrity (i.e. elongation) due to the improved pushability and navigability generated by the interaction of the devices since the Funnel Catheter is configured to alter the stiffness of a portion of the ANA DC as it moves through that portion of the ANA DC.

[0133] This study shows that commercially available delivery catheters seem not suitable to deliver and navigate (without alteration of their integrity, i.e. elongation) with the Funnel Catheter manufactured by Anaconda Biomed to a brain target location, e.g. beyond the carotid syphon.

Example 2: Tensile Testing of Commercially Available Catheter Devices in Comparison with the Delivery Catheter of the ANA System

[0134] The purpose of this experimental test was to measure the tensile force in the distal section of the Delivery Catheter of the ANA system (described in Example 1, hereinafter ANA DC) and compare it against other commercially available neurovascular catheters, such as ACE68 (manufactured by Penumbra, hereinafter ACE) and React 71 (manufactured by Medtronic, hereinafter React).

[0135] The evaluation of the tensile force curve in the distal section was quantified in order to provide quantitative insight regarding the capability of the catheters to withstand the forces to move the Funnel Catheter (FC) of the ANA system described in Example 1 inside its structure and also to determine the desired flexibility for the final design of the ANA DC in order to avoid elongation during neurovascular interventions.

[0136] Methods

[0137] At least 3 units (n>=3) of the following catheters were evaluated; ANA DC, ACE and React. The tensile testing evaluation was performed at 10 cm position from the distal tip of the catheters. The tensile testing apparatus consists of a means applying and accurately measuring axial loads to a specimen gripped by both sides with a gauge length distance of 10 mm. The maximum force was recorded when the gripping elements separate from each other at a rate of 200 mm/min. This testing method is according the ISO 10555-1.

[0138] Results

[0139] Table 10 shows the force measured at 25% of elongation to have a correlation with the elastic behavior of the devices. In this case, as higher the force, the catheter has higher axial resistance.

TABLE-US-00010 TABLE 10 Force [N] at 25% Elongation (10 cm from distal tip) Device Average Minimum Maximum Std. Dev. ANA DC (n = 3) 5.30 5.21 5.38 0.09 ACE (n = 4) 2.44 2.12 2.73 0.29 React (n = 4) 1.81 0.86 2.32 0.65

[0140] ANA DC obtained the higher value of axial resistance, so it is the most suitable catheter to carry another medical device inside avoiding at the same time the elongation of the catheter during the intervention.

[0141] Conclusions

[0142] Tensile tests showed differences between the axial resistance for ANA Delivery Catheter and different commercially available neurovascular catheters. The lower values of forces in React and ACE makes these catheters structures not compatible with the Funnel Catheter because they would suffer from elongation during the intervention due to the movement of the Funnel Catheter. In conclusion, commercially available catheters are not suitable to carry the Funnel Catheter of the ANA system inside.

[0143] Finally, Example 1 and 2 showed good results for the ANA Delivery Catheter to maintain its integrity (i.e. without significant elongation) during interventions and is the best candidate to accommodate a Funnel Catheter inside its structure.

[0144] Unless otherwise indicated, all numbers expressing measurements, conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about”. Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by the presently disclosed subject matter. Throughout the description and claims the word “comprise” and its variations such as “comprising” are not intended to exclude other technical features, additives, components, or steps. Additional objects, advantages and features of the invention will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the invention. Furthermore, the present invention covers all possible combinations of particular and preferred embodiments described herein.

[0145] According to descriptions above, various alterations may be achieved. All applications, modifications and alterations required to be protected in the claims may be within the protection scope of the present disclosure.

[0146] The scope of the present invention is defined in the following set of claims.