An access system including a guide extension catheter and a dilator adapted to be held in alignment with the guide extension catheter

Abstract

An access system (10) adapted for accessing a desired location within a patient's vasculature includes an outer catheter such as a guide extension catheter (12) and an inner catheter such as a dilator (14). The outer catheter includes an outer catheter push rod (24), an outer catheter sheath (16) extending distally from the outer catheter push rod, and a first engagement feature (38) disposed within a distal region of the outer catheter sheath. The inner catheter includes an inner catheter push rod (36), an inner catheter body (26) extending distally from the inner catheter push rod, and a second engagement feature (50) disposed within a proximal region of the inner catheter body, the second engagement feature being adapted to releasably engage the first engagement feature.

Description

Cross-reference to related applications This application claims priority to U.S. Provisional Application No. 63 / 627,928, filed February 1, 2024, the entire disclosure of which is incorporated herein by reference. Technical Field

[0001] This disclosure relates to access systems, and more particularly to access systems including a guiding extension catheter and a dilator, each of the guiding extension catheter and the dilator including features adapted to allow the dilator to remain aligned with the guiding extension catheter. Background Technology

[0002] Guided extension catheters can be used to enhance guidance support when navigating complex, tortuous anatomical structures. However, guided extension catheters have a distal opening that is larger than the guidewire along which they are advanced, meaning that the catheter may not accurately track the guidewire, especially when navigating bends or bifurcations. Physicians have developed numerous balloon-assisted tracking techniques to improve guideline tracking, including balloons as guides, balloons as dilators, inchworm techniques, and anchoring balloons. Dilators have also been developed. The desired approach is an access system comprising a guided extension catheter and a dilator, each including features that allow the dilator to remain aligned with the catheter. Summary of the Invention

[0003] This disclosure provides designs, materials, manufacturing methods, and alternatives for using medical devices. One example is an access system adapted to reach a desired location within a patient's vascular system. The access system includes a guiding extension catheter and a dilator. The extension catheter includes a sheath extending from a distal region to a proximal region, a first push rod extending proximally from the proximal region of the sheath, and a first engagement feature disposed within the distal region of the sheath. The dilator includes a dilator body comprising a distal conical region and a proximal region, a second push rod extending proximally from the conical dilator body, and a second engagement feature disposed within the proximal region of the dilator body. The second engagement feature is adapted to releasably engage the first engagement feature.

[0004] Alternatively or additionally, the first engagement feature may include a first marking strip fixed around the sheath and a second marking strip spaced apart from and fixed around the sheath. The second marking strip is adapted to allow the second engagement feature to move distally beyond the second marking strip.

[0005] Alternatively or additionally, the first marking strip may have a ring shape, and the second marking strip may have a C-shaped shape.

[0006] Alternatively or additionally, the second engagement feature may include an annular protrusion on the proximal region of the expander body.

[0007] Alternatively or additionally, the second engagement feature may include an O-ring disposed on the proximal region of the expander body.

[0008] Alternatively or additionally, the second engagement feature may include one or more protrusions protruding from the proximal region of the expander body.

[0009] Alternatively or additionally, the system may further include a pusher reinforcement disposed on the second pusher.

[0010] Alternatively or additionally, the pusher reinforcement may be adapted to engage with the proximal region of the sheath.

[0011] Alternatively or additionally, the pusher reinforcement can be positioned on the second push rod at a location that prevents the proximal region of the expander body from moving distally beyond the distal region of the sheath.

[0012] Alternatively or additionally, the actuation reinforcement may include a proximal collar stop having a distal region adapted to complement the proximal region of the sheath.

[0013] Alternatively or additionally, the second push rod may include one or more bends forming the push reinforcement.

[0014] Alternatively or additionally, the sheath may have a flared distal tip, and the size of the expander body may be set to cover the flared distal tip.

[0015] Alternatively or additionally, the expander body may have a hollow portion that allows the expander body to be pulled into the sheath.

[0016] Alternatively or additionally, the entry system may also include a retaining member adapted to be releasably secured to the first push rod and the second push rod.

[0017] Alternatively or additionally, the retaining member may include a clip.

[0018] Alternatively or additionally, the retaining member may include a peelable sheath.

[0019] Another example can be seen in an access system adapted to reach a desired location within a patient's vascular system. This access system includes a guiding extension catheter and a dilator. The guiding extension catheter includes a sheath extending from a distal region to a proximal region, a first push rod extending proximally from the proximal region of the sheath, a first marking band fixed around the sheath, and a second marking band spaced apart from and fixed around the sheath. The dilator includes a dilator body comprising a distal conical region and a proximal region, a second push rod extending proximally from the conical dilator body, and a protrusion disposed within the proximal region of the dilator body, the protrusion being releasably secured between the first and second marking bands.

[0020] Alternatively or additionally, the second marking strip may have a C-shape, which allows the second marking strip to flex as the protrusion moves toward the first marking strip across the second marking strip.

[0021] Another example can be seen in an access system adapted to reach a desired location within a patient's vascular system. This access system includes an external catheter and an internal catheter. The external catheter includes an external catheter pusher, an external catheter sheath extending distally from the external catheter pusher, and a first engagement feature disposed in a distal region of the external catheter sheath. The internal catheter includes an internal catheter pusher, an internal catheter body extending distally from the internal catheter pusher, and a second engagement feature disposed in a proximal region of the internal catheter body and adapted to releasably engage the first engagement feature.

[0022] Alternatively or additionally, the external catheter may include a guiding extension catheter, and the internal catheter may include a dilator adapted to extend distally from the external catheter sheath as the internal catheter is advanced through the external catheter.

[0023] The above overview of some example embodiments is not intended to describe every disclosed embodiment or implementation of this disclosure. Attached Figure Description

[0024] This disclosure will be more fully understood by taking into consideration the following detailed description of various embodiments in conjunction with the accompanying drawings, in which:

[0025] Figure 1 This is a schematic diagram of an illustrative access system that includes a guiding extension catheter and a dilator positioned near the guiding extension catheter;

[0026] Figure 2 yes Figure 1 An illustrative diagram of the access system shows the dilator extending through the guide extension catheter;

[0027] Figure 3 This is a schematic diagram of an illustrative access system, which includes a guiding extension catheter and a dilator positioned near the illustrative guiding extension catheter;

[0028] Figure 4 yes Figure 3 An illustrative diagram of the access system shows the dilator extending through the guide extension catheter;

[0029] Figure 5 This is a schematic diagram of an illustrative access system, which includes a guiding extension catheter and a dilator positioned near the illustrative guiding extension catheter;

[0030] Figure 6 yes Figure 5 An illustrative diagram of the access system shows the dilator extending through the guide extension catheter;

[0031] Figure 7 This is a schematic diagram of an illustrative access system, which includes a guiding extension catheter and a dilator positioned near the illustrative guiding extension catheter;

[0032] Figure 8 yes Figure 7 An illustrative diagram of the access system shows the dilator extending through the guide extension catheter;

[0033] Figure 9 This is a schematic diagram illustrating the guiding extension catheter;

[0034] Figure 10 This is an illustrative diagram of an access system, which includes... Figure 9 The guiding extension catheter and the dilator extending distally from the guiding extension catheter;

[0035] Figure 11 yes Figure 10 An illustrative diagram of the entry system shows the dilator being retracted proximally into the guiding extension catheter;

[0036] Figure 12 This is an illustrative diagram of the system entry, shown in combination with an illustrative retainer clip;

[0037] Figure 13 This is an illustrative diagram of the system entry, shown in combination with an illustrative retainer clip;

[0038] Figure 14 This is a schematic diagram of an illustrative entry system, shown in combination with an illustrative removable sheath; and

[0039] Figure 15 This is a schematic diagram illustrating the entry system, shown in combination with an illustrative removable sheath.

[0040] Although this disclosure can be modified in various variations and alternatives, its specific details have been illustrated by way of example in the accompanying drawings and will be described in detail. However, it should be understood that it is not intended to limit aspects of this disclosure to the specific embodiments described. Rather, it is intended to cover all variations, equivalents, and alternatives falling within the spirit and scope of this disclosure. Detailed Implementation

[0041] All numerical values ​​in this document are assumed to be modified by the term "about," whether explicitly stated or not. The term "about" generally refers to a range of numerical values ​​that a person skilled in the art would consider equivalent to the stated value (e.g., having the same function or result). In many cases, the term "about" can mean a numerical value that includes rounding to the nearest significant figure.

[0042] The description of a numerical range by endpoints includes all values ​​within that range (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0043] Although some suitable dimensions, ranges and / or values ​​related to various components, features and / or specifications are disclosed, those skilled in the art will understand, inspired by this disclosure, that desired dimensions, ranges and / or values ​​may deviate from those explicitly disclosed.

[0044] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural references unless expressly specified otherwise. As used in this specification and the appended claims, the term “or” is generally used to mean “and / or” unless expressly specified otherwise.

[0045] The following detailed description should be read with reference to the accompanying drawings, in which similar elements are labeled with the same numbers. The specification and drawings (not necessarily drawn to scale) depict illustrative embodiments and are not intended to limit the scope of this disclosure. The depicted illustrative embodiments are intended to be exemplary only. Selected features of any illustrative embodiment may be incorporated into another embodiment unless expressly stated otherwise.

[0046] Guide extension catheters can be used in combination with guide catheters to extend the effective length of the guide catheter. In some cases, guide extension catheters can be used in combination with dilators to effectively provide a non-invasive tip for the guide extension catheter. In some cases, the guide extension catheter can be considered an external catheter, and the dilator can be considered an internal catheter. Using a dilator can also improve the tracking of the guide extension catheter on the guidewire because the inner diameter of the guide extension catheter is larger than, or even significantly larger than, the outer diameter of the guidewire on which the guide extension catheter is being advanced. It should be understood that guide extension catheters typically have a sufficiently large inner diameter to allow other devices to be advanced through the guide catheter and the accompanying guide extension catheter. Dilators typically have a guidewire lumen extending through the dilator, the size of which is configured to accommodate the guidewire, but not significantly larger than the outer diameter of the guidewire. For example, the inner diameter of the guidewire lumen extending through the dilator can be ten percent or less larger than the outer diameter of the guidewire.

[0047] Figure 1 This is a schematic diagram of an illustrative access system 10, which can be used with any of a variety of different guiding catheters (not shown). The illustrative access system 10 includes an external catheter 12 and an internal catheter 14. In some cases, the external catheter 12 can be considered a guiding extension catheter 12. In some cases, the internal catheter 14 can be considered a dilator 14. Figure 1 In this configuration, the dilator 14 is positioned immediately adjacent to the guiding extension catheter 12. Figure 2 The expander 14 is shown being advanced distally into the guide extension catheter 12, in a position ready for use in the entry system 10.

[0048] The dilator 14 can be used in conjunction with the guiding extension catheter 12 to navigate into and / or through a tortuous vascular system. The guiding extension catheter 12 includes a sheath 16 that can be considered to extend from a distal region 18 to a proximal region 20. As shown, the proximal region 20 may include a proximal tapered end 22, but this is not always necessary. In some cases, the proximal region 20 may include a non-tapered proximal end 22. As an example, the proximal end 22 may be tapered relative to the longitudinal extension of the sheath 16 at an angle of approximately 30 to 70 degrees, or approximately 40 to 60 degrees, or approximately 50 degrees ± 5 degrees.

[0049] The guiding extension catheter 12 includes a push rod 24 that extends proximally from the proximal region 20 of the sheath 16. The push rod 24 can be secured to the sheath 16 in any suitable manner. The push rod 24 can be made of metal and can be, for example, welded to a metal collar (not shown) that is embedded in or otherwise disposed within the sheath 16. The dilator 14 includes a dilator body 26 having a distal tapered region 28 and a proximal region 30. The distal tapered region 28 can be considered to have a conical taper profile, although other taper profiles are conceivable. The dilator body 26 can be a polymer structure and can be molded via a molding process such as injection molding. In some cases, the distal tapered region 28 has a smooth taper diameter that tapers from a distal end 32 to its maximum value at a point 34 adjacent to the proximal region 30. The diameter of the distal tapered region 28 at distal end 32, point 34, and all portions therein can vary depending on the diameter of the guidewire that the dilator body 26 is intended to advance thereon and the diameter of the sheath 16 with which the dilator body 26 will be used. As an example, distal end 32 can have a minimum diameter ranging from 0.017 inches to 0.020 inches. As another example, distal end 32 can have a minimum diameter of approximately 0.50 mm (0.020 inches). Point 34 will have a diameter that varies depending on whether the sheath 16 is part of a 5-French, 6-French, or 7-French guiding extension catheter. In one example, the distal tapered region 28 can have a total length of approximately 15 mm (0.59 inches). In one example, the distal tapered region 28 can have a maximum diameter (at point 34) of approximately 1.68 mm (0.066 inches).

[0050] Expander 14 includes a push rod 36. The push rod 36 may be, for example, a wire and may be secured to expander body 26 in any suitable manner. In some cases, the push rod 36 may be secured to expander body 26 with an adhesive. Expander body 26 may be overmolded onto push rod 36. In some cases, push rod 36 may include a shape stamped into push rod 36 prior to overmolding expander body 26 onto push rod 36, which facilitates an interference fit between expander body 26 and push rod 36. As another example, expander body 26 may be reflowed while remaining adjacent to push rod 36. This may allow recesses formed in the outer surface of expander body 26 to wrap around push rod 36. In some cases, adhesives may be used in addition to a reflow process. In some cases, heat shrink tubing may help secure expander body 26 to push rod 36. Push rod 36 may include raised metal features that enhance the fixation provided by overmolding. In some cases, raised metal features can provide a snap-fit ​​engagement with the expander body 26.

[0051] In some cases, the guiding extension catheter 12 and the dilator 14 are adapted to be used together and may include features that facilitate their use. For example, the guiding extension catheter 12 may include a first engagement feature 38 disposed within a distal region 18 of the sheath 16, and the dilator 14 may include a second engagement feature 40 disposed within a proximal region 30 of the dilator body 26. The first engagement feature 38 may be adapted to receive the second engagement feature 40, thereby securing the dilator 14 in place relative to the guiding extension catheter 12. In some cases, the second engagement feature 40 may be considered adapted to releasably engage the first engagement feature 38. In some cases, the first engagement feature 38 may include a first marking band 42 and a second marking band 44 axially spaced from the first marking band 42. In some cases, the first marking band 42 and the second marking band 44 may be spaced about 0.5 mm apart to accommodate the second engagement feature 40 between them. The first marking band 42 may have an annular shape. The second marking band 44 may have an annular form but with segment 46 removed, thereby providing a C-shaped profile for the second marking band 44.

[0052] In some cases, the first marking band 42 and the second marking band 44 may each be disposed on the outer surface of the sheath 16. The first marking band 42 and the second marking band 44 may each have an inner diameter smaller than the outer diameter of the sheath 16, meaning that the first marking band 42 and the second marking band 44 each partially compress the sheath 16. As a result, the lumen 48 extending through the sheath 16 may exhibit a first diameter reduction corresponding to the location of the first marking band 42 and a second diameter reduction corresponding to the location of the second marking band 44. In some cases, it is precisely the first and second diameter reductions that serve to secure the second engagement feature 40 between them. Because the second marking band 44 has a C-shaped profile, it is able to flex as the expander 14 is advanced distally within the lumen 48 and the second engagement feature 40 passes through the second marking band 44.

[0053] In some cases, the second engagement feature 40 may include an annular protrusion 50 disposed within the proximal region 30 of the expander body 26. The annular protrusion 50 may be molded into the expander body 26. In some cases, the annular protrusion 50 may actually be a rigid O-ring disposed around the expander body 26. Although not shown, the proximal region 30 of the expander body 26 may include one or more recesses adapted to secure the rigid O-ring in place. The annular protrusion 50 may be sized to fit, for example, between the first marking band 42 and the second marking band 44. As a result, the expander 14 can be moved distally into the lumen 48 defined by the sheath 16. The first engagement feature 38 (such as the first marking band 42 and the second marking band 44) ​​may be positioned in the distal region 18 of the sheath 16 such that when the distal tapered region 28 extends distally from the sheath 16 (e.g. Figure 2 As seen in the diagram, the second engagement feature 40 snaps into position between the first marking band 42 and the second marking band 44. As a result, the guide extension catheter 12 and the dilator 14 can move together as a component.

[0054] Figure 3 This is an illustrative diagram of entry system 52, which is similar to entry system 10 but includes a slightly different expander. Entry system 52 includes... Figure 1 and Figure 2 The guiding extension catheter 12 and dilator 54 are discussed. Figure 3 In this configuration, the dilator 54 is positioned immediately adjacent to the guiding extension catheter 12. Figure 4 The expander 54 is shown being advanced distally into the guide extension catheter 12, positioned in a ready-to-use position within the access system 52. Like expander 14, expander 54 includes an expander body 26 having a distal tapered region 28 and a proximal region 30. In some cases, the distal tapered region 28 has a smooth tapered diameter that tapers from a minimum diameter at the distal end 32 to a maximum diameter at a point 34 adjacent to the proximal region 30, and thus can have a conical shape. Expander 54 includes a push rod 36. The push rod 36 can be secured to expander body 26 in any suitable manner. Expander 54 includes a second engagement feature 56 adapted to releasably engage a first engagement feature 38. In some cases, the second engagement feature 56 may include one or more protrusions 58 adapted to engage the first engagement feature 38. Instead of annular protrusions (such as...), Figure 1 As shown in the diagram, the second engagement feature 56 may include one or more different protrusions. The second engagement feature 56 may include any number of bumps 58, although only one is shown. Each of the one or more bumps 58 may be integrally molded as part of the expander body 26. In some cases, each of the one or more bumps 58 may be formed separately and then subsequently fixed to the expander body 26, such as with adhesive.

[0055] The dimensions of each of one or more protrusions 58 can be set to fit, for example, between the first marking band 42 and the second marking band 44. As a result, the expander 14 can be moved distally into the lumen 48 defined by the sheath 16. First engagement features 38 (such as the first marking band 42 and the second marking band 44) ​​can be positioned in the distal region 18 of the sheath 16 such that when the distal tapered region 28 extends distally from the sheath 16 (e.g.) Figure 4 As seen in the diagram, the second engagement feature 56 (such as one or more protrusions 58) snaps into position between the first marking band 42 and the second marking band 44. As a result, the guide extension catheter 12 and the dilator 14 can move together as a component.

[0056] Figure 5 This is a schematic diagram of an illustrative access system 60, which can be used with any of a variety of different guiding catheters (not shown). The illustrative access system 60 includes an external catheter 62 and an internal catheter 64. In some cases, the external catheter 62 may be considered a guiding extension catheter 62. In some cases, the internal catheter 64 may be considered a dilator 64. Figure 5 In this configuration, the dilator 64 is positioned immediately adjacent to the guiding extension catheter 62. Figure 6 The expander 64 is shown being advanced distally into the guide extension catheter 62, positioned in the ready-to-use entry system 60.

[0057] The dilator 64 can be used in conjunction with the guiding extension catheter 62 to navigate into and / or through a tortuous vascular system. The guiding extension catheter 62 includes a sheath 66 that can be considered to extend from a distal region 68 to a proximal region 70. In some cases, the proximal region 70 may include a proximal tapered end 72, but this is not always necessary. The guiding extension catheter 62 includes a pusher 24 extending proximally from the proximal region 70 of the sheath 66. The pusher 24 can be secured to the sheath 66 in any suitable manner. The dilator 64 includes a dilator body 26 having a distal tapered region 28 and a proximal region 30. In some cases, the distal tapered region 28 has a smooth taper diameter that tapers from a minimum diameter at the distal end 32 to a maximum diameter at a point 34 adjacent to the proximal region 30, and thus has a conical shape. The dilator 64 includes a pusher 36. The push rod 36 can be fixed to the expander body 26 in any suitable manner.

[0058] In some cases, the guiding extension catheter 62 and the dilator 64 are adapted to be used together and may include features that facilitate their use. For example, the guiding extension catheter 62 may include a first engagement feature (not shown) disposed within the distal region 68 of the sheath 66, and the dilator 64 may include a second engagement feature 74 disposed within the proximal region 30 of the dilator body 26. In some cases, the first engagement feature may be similar to... Figures 1 to 4 The first engagement feature 38 is shown. In some cases, the second engagement feature 74 may include something similar to... Figure 3 and Figure 4 The protrusion 76 of one or more protrusions 58 shown. The first engagement feature may be adapted to receive a second engagement feature 74, thereby securing the dilator 64 in place relative to the guide extension conduit 62. In some cases, the second engagement feature 74 may be considered adapted to releasably engage the first engagement feature.

[0059] In some cases, the dilator 64 may include a pusher reinforcement 78 disposed on the second pusher 36. The pusher reinforcement 78 helps transfer thrust from the second pusher 36 to the guiding extension catheter 62. In some cases, the pusher reinforcement 78 also helps maintain alignment of the distal tapered region 28 of the dilator body 26 with the distal region 68 of the sheath 66 and prevents the distal tapered region 28 of the dilator body 26 from moving distal to the distal region 68 of the sheath 66. The pusher reinforcement 78 can take many forms and can be attached to the second pusher 36 in any suitable manner. For example, the pusher reinforcement 78 may be made of a polymer and may be attached to the second pusher 36 with an adhesive. In some cases, using an adhesive to attach the pusher reinforcement 78 to the second pusher 36 allows for customized, precise positioning of the pusher reinforcement 78 relative to the second pusher 36. In some cases, the pusher reinforcement 78 may be overmolded onto the second pusher 36. In some cases, the pusher reinforcement 78 can be fixed to the second push rod 36 at a position that is properly aligned with the distal tapered region 28 of the expander body 26 and the distal region 68 of the sheath 66.

[0060] In some cases, the push reinforcement 78 may be a proximal collar stop 78, which includes a collar stop body 80 fixed to the second push rod 36. The collar stop body 80 includes an angled distal portion 82 and a proximal portion 84. The angled distal portion 82 defines an angled distal surface 86. In some cases, the angled distal surface 86 of the push reinforcement 78 mates with the proximal tapered end 72 of the sheath 66. In some cases, the angled distal surface 86 of the push reinforcement 78 may not angularly mate with the proximal tapered end 72. The diameter of the angled distal portion 82 and / or proximal portion 84 of the collar stop body 80 may be larger than the proximal tapered end 72, provided that the diameter of the angled distal portion 82 and / or proximal portion 84 of the collar stop body 80 fits within any guide tube used with the entry system 60. Figure 6 As seen, the angled distal surface 86 of the pusher 78 is aligned with the proximal tapered end 72 of the sheath 66. As a result, the thrust applied to the second pusher 36 will be transmitted to the sheath 66 of the guide extension catheter 62.

[0061] Figure 7 This is a schematic diagram of an illustrative access system 81, which can be used with any of a variety of different guide tubes (not shown). The illustrative access system 81 includes an external conduit 62 (as per [reference]). Figure 5 and Figure 6 (As described) and the inner catheter 85. In some cases, the outer catheter 62 may be considered as the guiding extension catheter 62. In some cases, the inner catheter 85 may be considered as the dilator 85. Figure 7In the middle, the dilator 85 is positioned immediately adjacent to the guide extension catheter 62. Figure 8 The expander 85 is shown being advanced distally into the guide extension catheter 62, positioned in the ready-to-use entry system 81.

[0062] The dilator 85 can be used in conjunction with the guiding extension catheter 62 to navigate into and / or through a tortuous vascular system. The dilator 85 includes a dilator body 26 having a distal tapered region 28 and a proximal region 30. In some cases, the distal tapered region 28 has a smooth tapered diameter that tapers from a minimum diameter at distal end 32 to a maximum diameter at point 34 adjacent to the proximal region 30. The dilator 85 includes a push rod 87. The push rod 87 can be secured to the dilator body 26 in any suitable manner. The push rod 87 can be, for example, a wire and can be secured to the dilator body 26 in any suitable manner. In some cases, the push rod 36 can be adhesively secured to the dilator body 26. The dilator body 26 can be overmolded onto the push rod 87. In some cases, the push rod 87 may include a shape stamped into the push rod 36 prior to overmolding the expander body 26 onto the push rod 87, which facilitates an interference fit between the expander body 26 and the push rod 87. As another example, the expander body 26 may be reflowed while remaining adjacent to the push rod 87. This allows a recess formed in the outer surface of the expander body 26 to enclose the push rod 87. In some cases, adhesives may be used in addition to the reflow process. In some cases, heat shrink tubing may help secure the expander body 26 to the push rod 87. The push rod 87 may include raised metal features that enhance the retention provided by the overmolding. In some cases, the raised metal features may provide a snap-fit ​​engagement with the expander body 26.

[0063] In some cases, the guiding extension catheter 62 and the dilator 85 are adapted to be used together and may include features that facilitate their use. For example, the guiding extension catheter 62 may include a first engagement feature (not shown) disposed within the distal region 68 of the sheath 66, and the dilator 85 may include a second engagement feature 74 disposed within the proximal region 30 of the dilator body 26. In some cases, the first engagement feature may be similar to... Figures 1 to 4 The first engagement feature 38 is shown. In some cases, the second engagement feature 74 may include something similar to... Figure 3 and Figure 4 The protrusion 76 of one or more protrusions 58 shown. The first engagement feature may be adapted to receive a second engagement feature 74, thereby securing the dilator 85 in place relative to the guide extension conduit 62. In some cases, the second engagement feature 74 may be considered adapted to releasably engage the first engagement feature.

[0064] In some cases, the dilator 85 may include a pusher reinforcement 88 disposed on the second pusher 87. The pusher reinforcement 88 helps transfer thrust from the second pusher 87 to the guiding extension catheter 62. In some cases, the pusher reinforcement 88 also helps maintain alignment of the distal tapered region 28 of the dilator body 26 with the distal region 68 of the sheath 66 and prevents the distal tapered region 28 of the dilator body 26 from moving distal to the distal region 68 of the sheath 66. The pusher reinforcement 88 may take various forms and may be attached to the second pusher 87 in any suitable manner. In some cases, the pusher reinforcement 88 may be attached to the second pusher 87 at a position corresponding to the proper alignment of the distal tapered region 28 of the dilator body 26 and the distal region 68 of the sheath 66.

[0065] In some cases, the push reinforcement 88 can be formed separately and then fixed to a suitable position on the second push rod 87. In some cases, as shown, the push reinforcement 88 includes one or more bends formed within the second push rod 87. The push reinforcement 88 may include a first segment 90 and a second segment 92, wherein the first segment 90 and the second segment 92 meet at a vertex 94. In some cases, it is precisely the vertex 94 that interacts with the lower angle (in the illustrated orientation) of the proximal tapered end 72 of the sheath 66. This can be, for example, in... Figure 8 As seen in the image, the thrust applied to the second push rod 87 will be transmitted to the sheath 66 of the guiding extension catheter 62.

[0066] In some cases, it may be desirable to be able to withdraw the deflated large balloon back into the guiding extension catheter. Figure 9 This is a schematic diagram of an illustrative guiding extension catheter 100, which includes a sheath 102 that can be considered to extend from a distal region 104 to a proximal region 106. In some cases, the proximal region 106 may include a proximal conical end 108, but this is not necessary in all cases. The guiding extension catheter 100 includes a pusher 110 extending proximally from the proximal region 106 of the sheath 102. The pusher 110 can be secured to the sheath 102 in any suitable manner. The guiding extension catheter 100 includes a flared distal tip 112 located within the distal region 104 of the sheath 102. It should be understood that the flared distal tip 112 facilitates easier retraction of a constricted (but previously inflated) balloon back into the sheath 102.

[0067] In some cases, the guiding extension catheter 100 can be used in combination with a dilator adapted to accommodate the flared distal tip 112 of the sheath 102. Figure 10This is a schematic diagram of an illustrative access system 114, which includes a guiding extension catheter 100 combined with a dilator 116. The dilator 116 includes a dilator body 118 having a distal tapered region 120 and a proximal region 122. In some cases, the distal tapered region 120 may have a conical shape. In some cases, the dilator body 118 also includes a hollow region 124 independent of a guidewire lumen (not shown) extending through the dilator body 118. In some cases, such as... Figure 10 As seen, the distal conical region 120 has a maximum diameter, which, while matching the outer diameter of the distal tip 112 of the flare, is larger than the diameter of the sheath 102. In some cases, the hollow region 124 allows the distal conical region 120 to reduce its maximum diameter as the expander 116 retracts proximally into the sheath 102, such as... Figure 11 As seen in the diagram. In some cases, the hollow region 124 may not be hollow, but may instead appear as, for example, as a foam portion of the expander body 118.

[0068] The dilator 116 is shown to include a protrusion 76 resembling one or more bumps 58. The dilator 116 may include annular protrusions 50 instead of protrusions 76. Although not shown, the guiding extension catheter 100 may include... Figures 1 to 4 The first engagement feature 38 shown is such as a first marking band 42 and a second marking band 44. In some cases, the expander 116 may include, for example... Figure 5 and Figure 6 The pusher reinforcement 78 shown, or Figure 7 and Figure 8 The pusher reinforcement 88 is shown. In some cases, the guide extension catheter 12 or guide extension catheter 62 may include a flared distal tip 112. In some cases, the dilator 14 or dilator 64 may include a hollow region 124, or otherwise be compressible to allow the dilator body 26 or dilator body 118 to be compressed as it is withdrawn proximally into the guide extension catheter.

[0069] In some cases, when advancing or withdrawing into system 10, system 60 or system 81, it may be desirable to keep push rod 24 (e.g., guide extension catheter 12) and push rod 36 (e.g., dilator 14) together. Figure 12 The entry system 81, shown in combination with the push rod retainer 130, is illustrated. The push rod retainer 130 can be shaped like an 8, or the mathematical symbol ∞ (infinity).

[0070] In some cases, the push rod retainer 130 may be adapted to allow the push rod retainer 130 to be removed from the push rods 24 and 87 once the control system 81 has been set in the guide tube. Figure 13The access system 60 is shown in combination with the push rod retainer 132. In some cases, the push rod retainer 132 will be held outside any hemostatic valve and will slide relative to the push rods 24 and 36 (as shown). Although not shown, the push rod retainer 130 and / or the push rod retainer 132 can also be used in combination with the access system 10.

[0071] In some cases, the push rod retainer 130 can be sized to remain outside any hemostatic valve and can be adapted to slide relative to push rods 24 and 87 as they are advanced through the hemostatic valve. The push rod retainer 130 is adapted to keep the two push rods 24 and 87 from being too far apart from each other. As an example, the hemostatic valve can have a 10 French size, or approximately 3.5 mm (0.14 in) in diameter, and therefore the push rod retainer 130 can have a maximum size ranging from approximately 5 mm (0.20 in) to approximately 10 mm (0.39 in). The push rod retainer 130 can be made from a variety of different materials, including metal or rigid plastic. In some cases, the push rod retainer 130 can be made from polycarbonate, polyether block amides (such as those commercially available under the name Pebax™), and ABS (acrylonitrile butadiene styrene). In some cases, the push rod retainer 130 can be made from polymers such as polyethylene.

[0072] Figure 14 An access system 81 combined with a resealable sheath 134 is shown. In some cases, the resealable sheath 134 may be used to hold pushers 24 and 87 together and prevent them from becoming entangled with each other during the advancement or withdrawal of access system 10, access system 60, or access system 81. In some cases, the resealable sheath 134 will have an outer diameter greater than 0.1 inches and will therefore remain outside any hemostatic valve and will slide relative to pushers 24 and 87. In some cases, the resealable sheath 134 is a polymer tube that includes a weakening line 138 that can facilitate the peeling of the resealable sheath 134. The resealable sheath 134 can have any suitable length, ranging from about 0.25 inches to several inches. As an example, the resealable sheath 134 can have a diameter ranging from about 5 mm to about 10 mm. In some cases, the resealable sheath 134 may include one or more tabs that can be gripped to facilitate the peeling of the resealable sheath 134. The peelable sheath 134 can be formed from any suitable polymer. In some cases, the wall thickness can be adjusted to suit the strength properties of a particular polymer.

[0073] Figure 15An access system 60 combined with a peelable sheath 136 is shown. In some cases, the peelable sheath 136 may be used to hold pushers 24 and 36 together during the advancement or withdrawal of access system 10, access system 60, or access system 81. In some cases, the peelable sheath 136 will be held outside any hemostatic valve and will slide relative to pushers 24 and 36. In some cases, the peelable sheath 136 is a polymer tube that includes a weakening line 140 that can facilitate the peeling of the peelable sheath 136. The peelable sheath 136 can have any suitable length, ranging from about 0.25 inches to several inches. As an example, the peelable sheath 136 can have a diameter ranging from about 5 mm to about 10 mm. In some cases, the peelable sheath 136 may include one or more tabs that can be gripped to facilitate the peeling of the peelable sheath 136. The peelable sheath 136 can be formed of any suitable polymer. In some cases, the wall thickness can be adjusted to suit the strength properties of a particular polymer. Although not shown, the removable sheath 134 and / or removable sheath 136 may also be used in combination with the access system 10.

[0074] Materials that can be used for the various components of the devices disclosed herein may include those typically associated with medical devices. The various components of the devices / systems disclosed herein may include metals, metal alloys, polymers (some examples of which are disclosed herein), metal-polymer composites, ceramics, combinations thereof, or other suitable materials. Examples of suitable metals and metal alloys include stainless steels such as 304V, 304L, and 316LV stainless steels; low-carbon steels; nickel-titanium alloys such as linearly elastic and / or hyperelastic nickel-titanium; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625, such as INCONEL® 625; UNS: N06022, such as HASTELLOY® C-22®; UNS: N10276, such as HASTELLOY® C276®; other HASTELLOY® alloys, etc.), nickel-copper alloys (e.g., UNS: N04400, such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, such as MP35-N®, etc.), and nickel-molybdenum alloys (e.g., UNS: N10665, such as HASTELLOY® ALLOY). B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, such as ELGILOY®, PHYNOX®, etc.); platinum-rich stainless steel; titanium; combinations thereof, etc.; or any other suitable material.

[0075] Examples of suitable polymers may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, such as DELRIN® available from DuPont), polyether block esters, polyurethanes (such as Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether esters (such as ARNITEL® available from DSM Engineering Plastics), ether or ester copolymers (such as butene / poly(alkylene ether) terephthalate and / or other polyester elastomers, such as HYTREL® available from DuPont), polyamides (such as DURETHAN® available from Bayer or from Elf... Atochem's CRISTAMID®, elastic polyamides, block polyamides / ethers, polyether block amides (PEBA, such as commercially available under the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA), silicones, polyethylene (PE), MARLEX® high-density polyethylene, MARLEX® low-density polyethylene, linear low-density polyethylene (e.g., REXELL®), polyesters, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polypropylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyether imide (PEI), polyphenylene sulfide (PPS), polyphenylene ether (PPO), poly(p-phenylene terephthalamide) (e.g., KEVLAR®), polysulfone, nylon, nylon-12 (such as those available from EMS American) Grilon obtains GRILAMID®, perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefins, polystyrene, epoxy resins, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS A), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites thereof. In some embodiments, the sheath may be blended with a liquid crystal polymer (LCP). For example, the blend may contain up to about 6% LCP.

[0076] In at least some embodiments, various components of the devices disclosed herein may be partially or entirely doped with, made of, or otherwise comprised of a radiopaque material. A radiopaque material is understood to be a material capable of producing a relatively bright image on a fluoroscopic screen or other imaging technique during a medical procedure. This relatively bright image helps the user of the device determine their location. Some examples of radiopaque materials may include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials loaded with radiopaque fillers, etc. Furthermore, other radiopaque marking strips and / or coils may be incorporated to achieve the same result.

[0077] It should be understood that this disclosure is illustrative in many respects only. Changes in detail may be made, particularly in terms of shape, size, and arrangement of steps, without departing from the scope of this disclosure. This may include, to appropriate extent, using any feature of one exemplary embodiment in other embodiments. Of course, the scope of this disclosure is defined by the language expressed in the appended claims.

Claims

1. An access system suitable for accessing a desired location within a patient's vascular system, the access system comprising: The guiding extension catheter includes: The sheath extends from the distal region to the proximal region; A first push rod extending proximally from the proximal region of the sheath; A first engagement feature is provided in the distal region of the sheath; and Expander, the expander comprising: The expander body includes the distal conical region and the proximal region; A second push rod extending proximally from the conical expander body; and A second engagement feature is disposed in the proximal region of the expander body, the second engagement feature being adapted to releasably engage the first engagement feature.

2. The entry system according to claim 1, wherein, The first engagement feature includes: A first marking band fixed around the sheath; and A second marking band spaced apart from the first marking band and fixed around the sheath; The second marking band is adapted to allow the second engagement feature to move distally across the second marking band.

3. The entry system according to claim 2, wherein, The first marking strip has a ring shape, and the second marking strip has a C-shaped shape.

4. The access system according to any one of claims 1 to 3, wherein, The second engagement feature includes an annular protrusion on the proximal region of the expander body, or an O-ring disposed on the proximal region of the expander body, or one or more protrusions protruding from the proximal region of the expander body.

5. The entry system according to any one of claims 1 to 4, further comprising a pusher reinforcement disposed on the second pusher, the pusher reinforcement being adapted to engage with the proximal region of the sheath.

6. The entry system according to claim 5, wherein, The pusher reinforcement is positioned on the second push rod at a location that prevents the proximal region of the expander body from moving distally beyond the distal region of the sheath.

7. The access system according to any one of claims 5 or 6, wherein, The actuating reinforcement includes a proximal collar stop having a distal region adapted to complement the proximal region of the sheath.

8. The access system according to any one of claims 5 or 6, wherein, The second push rod includes one or more bends forming the push reinforcement.

9. The access system according to any one of claims 1 to 8, wherein: The sheath has a flared distal tip; and The size of the expander body is set to cover the far top of the flare.

10. The access system according to claim 9, wherein, The expander body has a hollow portion that allows the expander body to be pulled into the sheath.

11. The entry system according to any one of claims 1 to 10, further comprising a retaining member adapted to be releasably secured to the first push rod and the second push rod.

12. The access system according to claim 11, wherein, The retaining member includes a clip or a removable sheath.

13. An access system suitable for accessing a desired location within a patient's vascular system, the access system comprising: The guiding extension catheter includes: The sheath extends from the distal region to the proximal region; A first push rod extending proximally from the proximal region of the sheath; A first marking band fixed around the sheath; and A second marking band spaced apart from the first marking band and fixed around the sheath; and Expander, the expander comprising: The expander body includes the distal conical region and the proximal region; A second push rod extending proximally from the conical expander body; and A protrusion disposed in the proximal region of the expander body, the protrusion being releasably secured between the first marking strip and the second marking strip.

14. The access system according to claim 13, wherein, The second marking strip has a C-shaped shape, which allows the second marking strip to flex as the protrusion moves toward the first marking strip across the second marking strip.

15. An access system adapted to access a desired location within a patient's vascular system, the access system comprising: External catheter, the external catheter comprising: External catheter push rod; External catheter sheath extending distally from the external catheter push rod; A first engagement feature is provided in the distal region of the external catheter sheath; and Internal catheter, the internal catheter comprising: Intracatheter pusher; The main body of the internal catheter extending distally from the internal catheter pusher; A second engagement feature is disposed in the proximal region of the inner catheter body, the second engagement feature being adapted to releasably engage the first engagement feature.

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