Expandable dilator

Abstract

An expandable dilator used with an expandable sheath includes a tapered distal tip, a body, a proximal end, and a shaft having a lumen extending longitudinally from the distal tip to the proximal end. The expandable dilator includes an expansion mechanism extending radially outward from the outer surface of the shaft. When the expandable dilator is pulled back proximal to the expandable sheath, the expansion mechanism engages with the distal end of the sheath and expands the sheath as the expansion mechanism moves proximal through the sheath.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of priority of U.S. Provisional Application No. 63 / 472,863, filed on June 14, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to medical devices, and more particularly, to expandable introducers and dilators, and methods of using such medical devices.

Background Art

[0003] For example, a variety of medical devices for medical applications, including medical devices used to deliver and implant artificial heart valves, have been developed. These medical devices can be used in various implant procedures and are manufactured and used according to any one of a variety of different methods. Known medical devices and methods each have specific advantages and disadvantages. There is a continuing need to provide alternative medical devices and alternative methods for manufacturing and using medical devices.

Summary of the Invention

[0004] This disclosure provides alternative examples of the design, materials, manufacturing methods, and uses of medical devices. An exemplary expandable dilator comprises a shaft having a tapered distal tip, a body, a proximal end, and a lumen extending longitudinally from the tapered distal tip to the proximal end, the shaft including a notch penetrating the side wall of the shaft adjacent to the tapered distal tip, and a slit extending through the side wall and from the notch to the proximal end; and an expander disposed within the notch, the expander having an outer diameter greater than the inner diameter of the lumen such that a portion of the expander extends through the notch, the expander including a tether fixed to the expander, the tether extending through the lumen and exiting from the proximal end of the shaft, wherein pulling the tether proximal causes the expander to move proximal through the shaft, and as the expander moves proximal through the shaft, the expander separates the opposing edges of the slit.

[0005] Alternatively, or in addition to, the proximal end of the tether is fixed to a knob connected to the proximal end of the shaft, and the knob is configured to pull the tether and expander proximal through the shaft.

[0006] Alternatively, or in addition to, the knob is configured to be pulled away from the proximal end of the shaft toward the proximal side, as in any of the embodiments described above. Alternatively, or in addition to, the knob is connected to the shaft by a breakable connector that can be broken by torsional or tensile forces.

[0007] Alternatively, or in addition to, any of the embodiments described above, the knob is rotatably connected to the proximal end of the shaft, and the tether is fixed to the knob, and the tether is wrapped around the knob as the expander is pulled proximal through the lumen by rotating the knob in a first direction relative to the shaft.

[0008] Alternatively, or in addition to, the shaft includes a plurality of channels extending longitudinally from the proximal end of a tapered distal tip along the entire length of the shaft. An exemplary expansion system comprises an expandable dilator and an expandable sheath, the expandable sheath having a distal end, a proximal end, a lumen extending between the distal and proximal ends, and at least one fold portion extending longitudinally from the distal end to the proximal end, each fold portion being defined by a circumferential overlap of the material forming the expandable sheath, the expandable sheath includes a distal ring configured to hold the expandable sheath in a compressed form, the distal ring having a long slit positioned above the fold portion, the distal ring being biased into a closed form, the distal ring being expandable when the expandable dilator is positioned within the expandable sheath and the expander is located distal to the distal end of the expandable sheath, the slit being expanded when the expander of the expandable dilator is pulled proximal, thereby unfolding the fold portion and expanding the inner diameter of the expandable sheath.

[0009] Another exemplary dilator used with an expandable sheath comprises a shaft having a tapered distal tip and a proximal tip, and a flexible ring positioned around the tapered distal tip, the flexible ring being configured to move axially on the shaft from the tapered distal tip, and the flexible ring having a plurality of projections extending radially outward from the outer surface of the flexible ring, and at least one tether, the at least one tether having a distal end fixed to the flexible ring and a proximal end extending axially along the outer surface of the tapered distal tip and entering into an opening in the shaft, the at least one tether extending through the lumen of the shaft, and the proximal end of the at least one tether extending proximal outward from the proximal end of the shaft.

[0010] Alternatively, or in addition to, the above embodiments, at least one tether includes two tethers fixed to opposing sides of a flexible ring, and the shaft opening includes two openings located on opposing sides of the shaft, with each tether extending into one of the two openings.

[0011] Alternatively, or in addition to, the multiple protrusions are multiple ridges extending longitudinally along the outer surface of the flexible ring. Alternatively, or in addition to, the opening is positioned on the shaft such that when the flexible ring is pulled onto the shaft, the opening is adjacent to the proximal end of the flexible ring.

[0012] A further exemplary dilator used with an expandable sheath comprises a shaft having a body with a tapered distal end and a proximal end, and a lumen extending longitudinally through the shaft, and at least one expandable member disposed on the body of the shaft, each expandable member configured to transition from a compressed state to an expanded state, wherein in the compressed state, the outer diameter of the expandable member is less than or equal to the outer diameter of the body, and in the expanded state, the outer diameter of the expandable member is greater than the outer diameter of the body, wherein when the shaft is placed in an expandable sheath, the expandable member is in the compressed state, and the expandable member is transitioned to the expanded state by moving the shaft distally out of the expandable sheath.

[0013] Alternatively, or in addition to, the above embodiment, the shaft has at least one recess on the body, and the extendable member extends over the recess. Alternatively, or in addition to, the expandable member is formed from a shape memory material and is biased into an expanded form.

[0014] Alternatively, or in addition to, any of the embodiments described above, the recess includes a spring, and the expandable member extends over the spring. Alternatively, or in addition to, any of the embodiments described above, the shaft has at least one rotational marker at its proximal end indicating the circumferential position of the expandable member.

[0015] Alternatively or in addition to any of the embodiments described above, the expandable member includes a compressible ring positioned between a tapered distal tip and the body, the shaft includes a tether fixed to the inner wall of the tapered distal tip and extending outward from the proximal end of the shaft through the lumen, the tapered distal tip being pulled toward the distal end of the body by pulling the tether proximal to the shaft, compressing the compressible ring so that the outer diameter of the compressible ring extends radially outward beyond the outer surface of the body, forming a circumferential ridge.

[0016] Alternatively, or in addition to, any of the embodiments described above, an expandable dilator further includes a knob connected to the proximal end of the shaft, the knob configured to pull the tether proximal to the shaft.

[0017] Alternatively, or in addition to, any of the embodiments described above, the knob is connected to the proximal end of the shaft using a breakable connector that can be broken by torsional or tensile forces, and the knob is configured to be pulled away from the proximal end of the shaft towards the proximal side.

[0018] Alternatively, or in addition to, any of the embodiments described above, the knob is rotatably connected to the proximal end of the shaft, and the tether is fixed to the knob, and by rotating the knob in a first direction relative to the shaft, the tether is wrapped around the knob as the tapered distal end is pulled towards the proximal end.

[0019] The above summary of some embodiments, aspects, and / or examples is not intended to describe any or all embodiments of the present disclosure. The following drawings and detailed description illustrate the above embodiments in more detail. [Brief explanation of the drawing]

[0020] The present disclosure can be more fully understood by considering the following detailed description of various embodiments in conjunction with the accompanying drawings. [Figure 1] FIG. 1 is a perspective view of an exemplary expandable dilator. [Figure 2] FIG. 2 is a side cross-sectional view taken along line 2-2 of FIG. 1. [Figure 3] FIG. 3 is an end perspective view of an exemplary expandable sheath. [Figure 4A] FIG. 4A is a side view of another exemplary expandable dilator in use. [Figure 4B] FIG. 4B is a side view of another exemplary expandable dilator in use. [Figure 4C] FIG. 4C is a side view of another exemplary expandable dilator in use. [Figure 4D] FIG. 4D is a side view of another exemplary expandable dilator in use. [Figure 4E] FIG. 4E is a side view of another exemplary expandable dilator in use. [Figures 5A-5D] FIGS. 5A-5D are side views of an exemplary expander shape. [Figure 6] FIG. 6 is a side cross-sectional view of an exemplary rotatable knob. [Figure 7] FIG. 7 is a side view of another exemplary rotatable knob. [Figure 8] FIG. 8 is a side view of an exemplary pull knob. [Figure 9A] FIG. 9A is a side view of another exemplary dilator having a flexible ring. [Figure 9B] FIG. 9B is a side view of another exemplary dilator having a flexible ring. [Figure 10A] T FIG. 10A is a side cross-sectional view of another exemplary dilator having an expandable tab. [Figure 10B] FIG. 10B is a side cross-sectional view of another exemplary dilator having an expandable tab. [Figure 10C]Figure 10C is a side cross-sectional view of another exemplary dilator with an expandable tab. [Figure 11A] Figure 11A is a partial side cross-sectional view of another exemplary dilator with a compressible ring. [Figure 11B] Figure 11B is a partial side cross-sectional view of another exemplary dilator with a compressible ring. [Figure 12] Figure 12 is a perspective view of an exemplary dilator with multiple channels. [Modes for carrying out the invention]

[0021] The embodiments of this disclosure may follow various modifications and alternative forms, the details of which are shown in the drawings as examples and described in detail. However, it should be understood that this is not intended to limit the embodiments to any particular set of embodiments illustrating the embodiments of this disclosure. On the contrary, it is intended to cover all modifications, equivalents, and alternative forms that fall within the spirit and scope of this disclosure.

[0022] The following definitions of terms shall apply unless otherwise given in a claim or herein. All numerical values, whether explicitly stated or not, are assumed to be modified by the term “approximately.” In the context of numerical values, “approximately” generally refers to a range of numerical values ​​that a person skilled in the art would consider to be equal to the stated value (e.g., having the same function or result). In many examples, “approximately” includes multiple numerical values ​​rounded to the nearest significant figure. Any other use of the term “approximately” (e.g., in a non-numerical context) is assumed, unless explicitly stated, to have a general and customary definition that can be understood and is consistent with the context of this Specified Publication.

[0023] Numerical ranges specified by endpoints include all numbers within that range, including the endpoint (for example, 1-5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). While several preferred dimensions, ranges, and / or values ​​for various components, features, and / or specifications are disclosed, a person skilled in the art inspired by this disclosure will understand that desired dimensions, ranges, and / or values ​​may deviate from those expressly disclosed.

[0024] As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include multiple references unless the content clearly indicates otherwise. Where used herein and in the appended claims, the term “or” is generally used to include “and / or” unless the content clearly indicates otherwise. For ease of understanding, it should be noted that certain elements of this disclosure may be described in the singular form even if there are multiple or repeated instances of that element within the embodiments in which it is disclosed. Each example of a feature includes and / or may be encompassed by a singular disclosure unless the opposite is expressly stated. For the sake of brevity and clarity, not all elements of this disclosure are necessarily shown in each drawing or described in detail below. However, the following descriptions may apply equally to any and / or all elements present, one or more of which exist, unless expressly refuted. In addition, not all examples of some elements or features are necessarily illustrated in each drawing for the sake of clarity.

[0025] Relative terms such as “proximal,” “distal,” “forward,” “backward,” and their variations may generally be considered in relation to the position, orientation, and / or movement of various elements of the apparatus with respect to the user / operator / manipulator; “proximal” and “backward” indicate or refer to being closer to or toward the user, while “distal” and “forward” indicate or refer to being further away from or away from the user. In some examples, the terms “proximal” and “distal” are arbitrarily assigned for the purpose of facilitating understanding of this disclosure, and such examples will be readily understood by those skilled in the art. Other relative terms such as “upstream,” “downstream,” “inflow,” and “outflow” refer to the direction of fluid flow within a lumen, such as a body lumen, a blood vessel, or within an apparatus.

[0026] The term “range” may be understood to mean the maximum measurement of a stated or identified dimension unless it is preceded by “minimum” or specifically identified as “minimum,” where “minimum” may be understood to mean the minimum measurement of the stated or identified dimension. For example, the term “outer range” may be understood to mean the maximum outer dimension, the term “radial range” may be understood to mean the maximum radial dimension, and the term “longitudinal range” may be understood to mean the maximum longitudinal range. Examples of “range” are all different (e.g., axial, longitudinal, transverse, radial, circumferential, etc.) and can be understood from the context in which they are used by a person skilled in the art. Generally, “range” may be considered to be the maximum possible dimension measured according to the intended use, while the term “minimum range” may be considered to be the minimum possible dimension measured according to the intended use. In some examples, “range” is measured orthogonally within a plane and / or cross-section, but may also be measured obliquely, radially, circumferentially (e.g., along an arc), etc., as is evident from the specific context. Furthermore, when the term "substantially" is used to mean that two dimensions are "substantially the same," it generally refers to a difference of 5% or less.

[0027] The terms “monolithic” and “integrated” generally refer to one or more elements made from or consisting of a single structure or basic unit / element. Monolithic elements and / or integrated elements shall exclude structures and / or features made by assembling or otherwise joining together multiple separate elements.

[0028] The descriptions in the specification such as “embodiments,” “several embodiments,” and “another embodiment” mean that the embodiments described possess a particular element, structure, or characteristic, but not all embodiments necessarily possess that particular element, structure, or characteristic. Furthermore, such phrasing does not necessarily refer to the same embodiment. Moreover, if a particular feature, structure, or characteristic is described in relation to one embodiment, a person skilled in the art will understand that, unless explicitly stated otherwise, that particular feature, structure, or characteristic may be applied in relation to other embodiments, whether or not it is explicitly stated. In other words, the various individual elements described below are assumed to be combinable or configurable with respect to each other to form other additional embodiments or to complement and / or enhance the embodiments described, as will be understood by a person skilled in the art, even if they are not explicitly shown in a particular combination.

[0029] For clarity, certain numerical nomenclature (e.g., First, Second, Third, Fourth, etc.) may be used throughout the specification and / or claims to name and / or identify various described and / or claimed features. This numerical nomenclature should be understood to be merely illustrative and not intended to be restrictive. In some embodiments, for the sake of brevity and clarity, changes and deviations from previously used numerical nomenclature may be made. That is, a feature identified as the “First” element may later be referred to as the “Second” element, the “Third” element, etc., or may be omitted entirely, and / or a different feature may be referred to as the “First” element. The meaning and / or designation in each instance will be obvious to those skilled in the art.

[0030] The following detailed description should be read in reference to drawings, which are not necessarily to scale, and similar elements in different drawings are given the same numbering. The detailed description and drawings are intended to be illustrative, not limiting, the disclosure. Those skilled in the art will recognize that various elements described and / or illustrated can be arranged in various combinations and configurations without departing from the scope of this disclosure. The modes and drawings for carrying out the invention illustrate exemplary embodiments of this disclosure. However, for the sake of clarity and ease of understanding, not all features and / or elements may be shown in each drawing, but unless otherwise specified, features and / or elements should be understood to be present.

[0031] In some cases, percutaneous medical procedures require the insertion, inflation, deflation, and removal of a balloon through an introducer sheath. For example, balloon valvuloplasty (BAV) may be performed before certain procedures of transcatheter aortic valve replacement (TAVR), prior to the inflation performed during TAVR delivery, with the balloon being inserted and removed through an introducer sheath. In some cases, problems may arise when withdrawing the BAV device through the distal end of an unexpanded introducer sheath. For example, the balloon may not deflate to its pre-inflation size, and problems may arise when the deflated balloon is pulled back into the introducer sheath. In some cases, the deflated balloon may cause the distal end of the introducer sheath to bend or deform. Some introducer sheaths may be expandable to allow relatively large medical devices to be delivered through them. These expandable sheaths may be configured to expand as larger medical devices move distally through them, but it may be desirable to provide a mechanism to expand the sheath so that the balloon can enter the distal end of the sheath without damaging the sheath when a deflated balloon is pulled proximally into the distal end of the expandable sheath. Often, a dilator is used when inserting the introducer sheath. The following examples illustrate various mechanisms for expanding an expandable sheath from the distal end toward the proximal end. Improved configurations combining a dilator and expansion can provide the desired expansion of the distal end of the expandable sheath without the need to insert a secondary tool to enable expansion.

[0032] Figure 1 shows an exemplary dilator 100 including a shaft 105 having a tapered distal tip 120, a body 110, and a proximal end 112. A knob 140 may be connected to the proximal end 112 of the body 110, and a lumen 130 may extend longitudinally from the distal tip to the proximal end of the knob 140. The shaft 105 may include a notch 114 penetrating the side wall of the shaft adjacent to the distal tip, and a slit 116 may extend through the side wall and from the notch 114 to the proximal end 112 of the shaft 105. In the illustrated embodiment, the notch 114 is provided in the tapered distal tip 120. The lumen 130 may extend entirely across the distal tip 120 and the body 110. See Figure 2. Lumen 130 may also extend through the knob 140 at least partially or completely.

[0033] Figure 3 shows an exemplary expandable sheath 60 used with any dilator described herein. The expandable sheath 60 may have one or more folds 62 that allow for circumferential expansion of the sheath. Each fold 62 includes a circumferential overlap of the material forming the sheath, and the folds 62 extend longitudinally along the sheath 60. In some examples, the folds 62 may extend along the entire length of the sheath 60. In some examples, a separating ring 70 may be connected to the distal end of the sheath, extending along the entire circumference of the sheath, and holding the sheath 60 in a compressed form. The ring 70 may include one or more elongated slits 72 to allow for the separation of a plurality of sections 74 of the ring 70 and expansion of the sheath 60. The slits 72 may be located above the folds 62. Multiple sections 74 of the ring 70 may be fixed to the sheath 60, so that when a radially outward force is applied to the inner surface of the sheath, the multiple sections 74 separate, and consequently the sheath expands at the location of each fold 62. The ring 70 may be biased into a closed configuration, in which case one or more slits 72 are closed and one or more fold 62 are in their overlapped configuration. When a medical device, such as a replacement heart valve, is moved distally through the expandable sheath 60, the medical device may apply a radially outward force to temporarily expand the sheath as the device moves through the sheath. In some examples, the sheath can return to its original circumferential shape and dimensions after the medical device has moved distally through the sheath. In this way, the sheath 60 may be biased into a compressed and folded configuration. Furthermore, radially outward forces may be applied by dilators as described herein.

[0034] Figure 4A shows a side view of another exemplary shaft 205. The notch 214 is shown positioned immediately proximal to the tapered distal tip 220 on the body 210. The slit 216 extends through the side wall of the body 210 from the notch 214 to the proximal end 212 of the shaft 205. The notch 214 and the slit 216 extend into the lumen 230 that extends along the entire length of the shaft 205. In other embodiments, the notch 114 may be located on the distal tip 120, as shown in Figure 1. Figure 4B shows a dilator 200 including the shaft 205 of Figure 4A, with an expander 250 located in the lumen 230 in the region of the notch 214. The dilator 200 is shown without a knob, but it should be understood that a knob may be used on any dilator described herein. The expander 250 may have an outer diameter larger than the inner diameter of the shaft lumen, such that a portion of the expander 250 extends through the notch 114, as shown in Figure 4C, which is a 90-degree rotation of Figure 4B. The expander 250 may include a tether 252 fixed to the expander, which extends proximal through the lumen and exits from the proximal end 212 of the shaft 205. The tether 252 may be a flexible wire.

[0035] Figures 4B and 4C show a dilator 200 positioned inside an introducer sheath, such as the expandable sheath 60 of Figure 3. As described above, the expandable sheath 60 may have one or more circumferential folds 62 that extend longitudinally along the entire length of the sheath. When the dilator 200 is positioned inside the expandable sheath 60 and the expander 250 is positioned distal to the distal end of the expandable sheath, the folds may be in a folded configuration. In some examples, the shaft 205 may be rotated so that the expander 250 is positioned below the folds within the expandable sheath 60. Figure 4D shows the initial expansion of the distal end of the sheath 60 when the tether 252 is pulled proximal to the shaft 205. As the dilator 250 is pulled proximal through the shaft 205 from the notch 214, the dilator 250 moves proximal through the shaft, separating the opposing edges of the slit 216 and deploying (expanding) the expandable sheath 60. See Figure 4E. Alternatively, when the dilator 250 is positioned proximal to the notch 214, the sheath 60 may be expanded by pulling the entire dilator 200, including the shaft 205 and the dilator 250, proximal through the sheath 60. By expanding the sheath 60, any deflated balloon or other medical device located distal to the sheath 60 can be drawn proximal through the expanded sheath 60.

[0036] Figures 5A to 5D show various shapes of the dilator 250 that may be used with the dilator described above. Exemplary shapes of the dilator 250 may include diamond (rhombus) (Figure 5A), ellipse (Figure 5B), circular (Figure 5C), teardrop (Figure 5D), etc. Any of the circular, ellipse, or teardrop dilators 250 may include a fin 251 (Figure 5B) that is arranged to extend through the notch 214 to allow separation of the slit 216.

[0037] In the example described above, the tether 252 can be manually pulled by grasping its proximal end and pulling while holding the shaft 205 in a stationary position. In other examples, the dilator may include a knob 240 connected to the proximal end of the shaft 205. In the example shown in Figure 6, the knob 240 is rotatably connected to the shaft 205 and has an extension of the lumen 230 extending through the shaft 205. A pin 242 may be positioned across the lumen 230 within the knob 240, and the proximal end of the tether 252 may be fixed to the pin 242. By rotating the knob 240 as indicated by arrow 245, the tether 252 is wrapped around the pin 242 and pulled proximal, resulting in the dilator attached to the distal end of the tether being pulled proximal through the shaft 205. In another example, as shown in Figure 7, the tether 252 may extend through an opening 246 on the side of the knob 240' which is rotatably connected to the proximal end of the shaft 205. The proximal end of the tether 252 can be secured to the outer surface of the knob 240' using a staple 253 or adhesive. By rotating the knob 240' relative to the shaft 205 as indicated by arrow 245, the tether 252 is wrapped around the outer surface of the knob 240', as shown in Figure 7.

[0038] Figure 8 shows another example of a dilator shaft 205 equipped with a tether 252 and a pull knob 340 configured to pull the dilator proximal through the shaft. In this example, the proximal end of the tether 252 may be fixed to the knob 340. The knob 340 may have a lumen that partially penetrates and extends through the knob 340, and the tether 252 may be fixed within the lumen. In other examples, the knob 340 may be solid, and the tether 252 may be fixed to the distal end of the knob 340. The knob 340 may be configured to be pulled proximal to the proximal end 212 of the shaft 205. In some examples, the knob 340 may be connected to the shaft 205 using a breakable (fragile) connector 215 that can be broken by torsional or tensile forces.

[0039] In another example, the dilator 300 may include a shaft 305 disposed within an expandable sheath 60 having one or more fold portions 62 as described above, and a flexible ring 380 having a plurality of projections 382 extending radially outward from the outer surface of the flexible ring. The flexible ring 380 may be configured to expand when moved axially on the shaft 305 from a tapered distal tip 320, as indicated by the arrow 345 shown in Figures 9A and 9B. The flexible ring 380 may be formed from an elastomer material and may include a radiopaque marker. In one example, the flexible ring 380 may be formed from a tungsten-containing polyether block amide (PEBA) so that the ring is radiopaque. The PEBA may have a Shore hardness of 35D. When the dilator 300 is disposed within the sheath 60 as described above, the plurality of projections 382 are configured to expand the fold portions 62 of the sheath 60. In some examples, the distal end of at least one tether 352 may be fixed to the flexible ring 380, the tether 352 may extend through an opening 346 in the shaft 305, and the proximal end of the tether 352 may extend outward from the proximal end of the shaft 305. Two tethers 352 fixed to opposing sides of the flexible ring 380 may allow for balanced retraction of the ring. In some examples, the tapered distal tip 320 may include a recess 323 on the tapered distal tip 320 configured to receive the flexible ring 380, as shown in Figure 9B. The flexible ring 380 can be pulled out of the recess 323 onto the shaft 305 by pulling one or more tethers 352 proximal. Each tether 352 may extend through separate openings 346 of the shaft 305, and the proximal end of the tether 352 may extend outward from the proximal end of the shaft 305. One or more tethers 352 may be manually pulled proximal to the shaft 305 to move the flexible ring 380 from its tapered distal end 320 onto the shaft 305. See Figure 9B. In other examples, the dilator 300 may include the aforementioned knob rotatably connected to the shaft 305, or a pull knob configured to be pulled proximal, with the proximal end of the tether 352 fixed to the knob.With the flexible ring 380 positioned on the shaft 305, the dilator 300 is pulled proximally through the sheath 60, causing the projection 382 to move into contact with the fold portion 62, which in turn expands the sheath 60, thereby allowing any deflated balloon or other medical device positioned distal to the sheath 60 to be pulled proximally through the expanded sheath 60.

[0040] Another exemplary dilator 400 is shown in Figures 10A to 10C. The dilator 400 may include a shaft 405 having a tapered distal end 420, a lumen 430 extending longitudinally along the entire length of the shaft, and a knob or hub 440 connected to the proximal end of the shaft, as shown in Figure 10A. The shaft 405 may include at least one expandable member, i.e., a tab 450, which is biased to a radially expanded form but is configured to be maintained in a compressed form if the dilator 400 is located within an expandable sheath 60 and the tab 450 is not located below a fold in the sheath 60, etc. In some examples, when the shaft 405 is located within the sheath 60, the tab 450 is in a compressed form (Figure 10A) and the outer diameter of the expandable tab 450 is less than or equal to the outer diameter of the shaft 405. The hub 440 may include one or more visible rotational markers 441 on the outer surface of the proximal end of the shaft 405 or on the hub 440. The markers 441 can be aligned with the tab 450 so that the user can determine the circumferential position of the tab 450 and rotate the shaft 405 for delivery to position the tab 450 between the folds 62 of the sheath 60, and rotate the shaft for deployment to position the tab 450 under one of the folds 62. One or more expandable tabs 450 may also include a radiopaque material. When the shaft 405 is moved distally to the outside of the sheath 60, the tab 450 transitions to an expanded form (Figure 10B), and the outer diameter of the tab 450 becomes larger than the outer diameter of the shaft 405.

[0041] The deployment of the tab 450 can be achieved by moving the shaft 405 distally to the sheath 60 until the tab 450 is distal to the distal end of the sheath 60. Without applying a radially inward compressive force to the sheath 60, as indicated by arrow 402, the tab 450 expands to the biased expanded position, as shown in Figure 10B. The dilator 400 may have multiple tabs 450, such as two, three, four, five, or six. In some examples, the dilator 400 may contain the same number of tabs 450 as the number of fold portions 62 within the sheath 60. Once the tabs 450 are in their expanded state, the shaft 405 may be rotated relative to the sheath 60 to align each tab 450 with the fold portion 62. Next, as the shaft 405 is pulled back into the sheath 60 and then pulled back proximally through the sheath 60, each tab 450 expands its associated fold portion 62, as shown in Figure 10C, thereby expanding the sheath 60.

[0042] The expandable tab 450 may be formed from a layer of shape memory material extending over a recess 452 adjacent to the distal tip 420, the layer of material being biased into a radially expanded form as shown in Figures 10A and 10B. In other examples, the tab 450 may be formed as a layer extending over the recess 452, and a spring mechanism 454 may be positioned within the recess 452 to bias the tab 450 into a radially expanded form as shown in Figure 10C. The spring mechanism 454 may be a spring-shaped element as shown in Figure 10C, or it may be a lever that biases the tab into a radially expanded form. In some examples, the tab 450 may be formed integrally with the shaft 405 as a layer of shaft material extending over the recess 452. In other examples, the expandable tab 450 may be formed as a fin extending over a spring and fixed to the shaft 405.

[0043] Figures 11A and 11B illustrate another embodiment in which the dilator 500 has a shaft 505 with a lumen extending through the shaft 505 and a knob 540 rotatably connected to the proximal end of the shaft, but a tapered distal tip 522 is longitudinally spaced from the distal end of the shaft 505 body 510 by a compressible ring 585. See Figure 11A. The shaft 505 may include a tether 552 fixed inside the tapered distal tip 522, the tether 552 extending outward from the proximal end of the shaft 505 through the lumen. By pulling the tether 552 proximal to the shaft 505, the distal tip 522 is axially pulled toward the distal end of the shaft body 510, compressing the compressible ring 585 axially. As a result, the outer diameter of the compressible ring 585 expands, extending radially outward beyond the outer surface of the shaft body 510, forming a circumferential ridge 587 as shown in Figure 11B. The sheath 60, although not shown in Figures 11A and 11B, similar to the projection 382 and expandable tab 450 of the flexible ring 380 described above, expands the fold portion 62 of the sheath 60 when the dilator 500 is pulled proximal to the sheath 60 when the compressible ring 585 is in a compressed state.

[0044] In some examples, the tether 552 may be manually pulled proximal to move the distal tip 522 and compress the compressible ring 585. In other examples, knobs 240, 340, as described above with respect to Figures 7 and 8, may be connected to the proximal end of the shaft 505. The knobs may be configured to pull the tether 552 proximal to the shaft 505. In some examples, the knob 340 may be connected to the proximal end of the shaft 505 using a breakable (fragile) connector 215 that can be broken by torsional or tensile forces, and the knob 340 may be configured to be pulled proximal to the proximal end of the shaft 505, as shown in Figure 8.

[0045] In the example shown in Figures 11A and 11B, the dilator 500 includes a rotatable knob 540 rotatably connected to the proximal end of the shaft 505. The knob 540 may have a lumen extension extending through the shaft 505. A pin 542 may be positioned across the lumen within the knob 540, and the proximal end of a tether 552 may be fixed to the pin 542. When the knob 540 is rotated as indicated by arrow 545, the tether 552 is wrapped around the pin 542, pulling the tether 552 proximal, thereby drawing the distal tip 522 closer to the distal end of the shaft 505, as indicated by arrow 541, and compressing the compressible ring 585 to form a circumferential ridge 587, as shown in Figure 11B.

[0046] Alternatively, the dilator 500 may have a knob as described above in relation to Figure 7, and the tether 552 may extend through an opening on the side of the knob, with its proximal end fixed to the outer surface of the knob. In this example, rotating the knob relative to the shaft causes the tether to wrap around the outer surface of the knob, and the distal tip 522 is drawn closer to the distal end of the shaft 505, compressing the compressible ring 585 to form a circumferential ridge 587.

[0047] In some examples, any of the shafts 105, 205, 305, 405, and 505 described herein may also include multiple elongated channels that allow blood and / or drugs to flow around and along the shaft. Figure 12 shows a dilator shaft 605 with multiple channels 613 extending longitudinally along the body 610 of the shaft 605. As shown, the multiple channels 613 extend from the proximal end of the distal tip 620 to the proximal region of the shaft 605. When the shaft 605 is placed in a body lumen, the multiple channels 613 may allow blood and / or drugs to be delivered from the proximal end of the shaft to a distal position on the shaft and from the distal position on the shaft to the proximal end region on the shaft, so as to move along the shaft. The multiple channels 613 may extend partially along the shaft 605 or may extend along the entire length of the shaft body 610 to the proximal end of the distal tip 620.

[0048] In some examples, various elements of the dilator shafts 105, 205, 305, 405, 605 and sheath 60 may be formed from polymers, elastomer polyamides, block polyamides / ethers, polyether block amides (PEBA, for example, available under the trade name PEBAX®), ethylene tetrafluoroethylene (ETFE), or other polymers commonly used in medical catheters. The expandable tab 450 may be formed from a shape memory material such as nitinol or a shape memory polymer. The entire dilator shaft 105 may be formed from a single monolithic component.

[0049] Any dimensions described in relation to the drawings above are illustrative only, and it should be understood that other dimensions are also assumed for the slit, dilator, and sheath. Materials that may be used for each component of the dilator for dilating the expandable sheath 60 (and / or other systems or components disclosed herein) and for its various components disclosed herein may include materials commonly associated with medical devices. For simplicity of explanation, the following description refers to the shaft 205 of the dilator (and its variations, systems, or components disclosed herein). However, this is not intended to limit the devices and methods described herein, and this description may apply to other elements, members, components, or devices disclosed herein.

[0050] In some embodiments, the dilator shaft 205 (and its variations, systems, or components disclosed herein) may be formed from polymers (some examples thereof are disclosed below), metals, metal-polymer composites, or other suitable materials. Some examples of suitable metals and alloys include stainless steel such as 444V, 444L, and 314LV stainless steel, mild steel, nickel-titanium alloys such as linear elastic and / or superelastic Nitinol, cobalt-chromium alloys, titanium and its alloys, alumina, and diamond-like carbon (DLC). Metals with coatings or titanium nitride coatings, 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®, and other HASTELLOY® alloys), nickel-copper alloys (e.g., UNS:N04400 such as MONEL® 400, NICKELVAC® 400, and NICORROS® 400), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS:R44035 such as MP35-N®), nickel-molybdenum alloys (e.g., HASTELLOY® ALLOY This includes UNS:N10665, such as B2 (registered trademark), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, and other nickel-tungsten or tungsten alloys, cobalt-chromium alloys, cobalt-chromium-molybdenum alloys (e.g., UNS:R44003, such as ELGILOY (registered trademark) and PHYNOX (registered trademark)), platinum-reinforced stainless steel, titanium, palladium, gold, and combinations thereof, or any other suitable material.

[0051] In at least some embodiments, part or all of the dilator shaft 205 (and its modifications, systems, or components disclosed herein) may also be doped with, formed from, or otherwise contain radiopaque material. Radiopaque material is understood to be a material that can produce a relatively bright image on a fluoroscopic screen or other imaging technique during a medical procedure. This relatively bright image assists the user in locating the dilator shaft 205 (and its modifications, systems, or components disclosed herein). Some examples of radiopaque materials include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, and polymer materials loaded with radiopaque fillers. Furthermore, other radiopaque marker bands and / or coils may also be incorporated into the design of the dilator shaft 205 (and its modifications, systems, or components disclosed herein) to achieve the same effect.

[0052] In some embodiments, the shaft 205 of the dilator (and any variations, systems, or components thereof disclosed herein) and / or parts thereof may be formed from or include polymers or other suitable materials. Some examples of suitable polymers include polytetrafluoroethylene (PTFE), ethylenetetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, e.g., DELRIN® available from DuPont), polyether block esters, polyurethane (e.g., Polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether esters (e.g., ARNITEL® available from DSM Engineering Plastics), ether or ester copolymers (e.g., butylene / poly(alkylene ether) phthalate and / or other polyester elastomers such as HYTREL® available from DuPont), polyamides (e.g., DURETHAN® or Elf available from Bayer). Available from Atochem: CRISTAMID®, elastomer polyamides, block polyamides / ethers, polyether block amides (PEBA, e.g., available under the trade name PEBAX®), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), Marlex® high-density polyethylene, Marlex® low-density polyethylene, linear low-density polyethylene (e.g., REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate, polyethylene naphthalate (PEN), polyether ether ketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide (e.g., KEVLAR®), polysulfone, nylon, nylon-12 (e.g., EMS AmericanMaterials may include GRILAMID® (available from Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefins, polystyrene, epoxy, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonates, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, and polymer / metal composites thereof. In some embodiments, the sheath can be mixed with liquid crystal polymer (LCP). For example, the mixture may contain up to about 6% LCP.

[0053] It should be understood that this disclosure is illustrative in many respects. Modifications can be made in detail, particularly with respect to shape, size, and process configuration, without exceeding the scope of this disclosure. This may include, to a reasonable extent, using any feature of one exemplary embodiment in other embodiments. The scope of this disclosure is, needless to say, defined in the language in which the appended claims are expressed.

Claims

1. An expandable dilator, A shaft having a tapered distal end, a body, a proximal end, and a lumen extending longitudinally from the tapered distal end to the proximal end, the shaft including a notch penetrating the side wall of the shaft adjacent to the tapered distal end, and a slit extending through the side wall and extending from the notch to the proximal end, An expander disposed within the notch, the expander having an outer diameter larger than the inner diameter of the lumen such that a portion of the expander extends through the notch, the expander including a tether fixed to the expander, the tether extending through the lumen and exiting from the proximal end of the shaft, An expandable dilator, wherein pulling the tether proximal causes the expander to move proximal through the shaft, and as the expander moves proximal through the shaft, the expander separates the opposing edges of the slit.

2. The expandable dilator according to claim 1, wherein the proximal end of the tether is fixed to a knob connected to the proximal end of the shaft, and the knob is configured to pull the tether and the expander proximal through the shaft.

3. The expandable dilator according to claim 2, wherein the knob is configured to be pulled away from the proximal end of the shaft toward the proximal side.

4. The expandable dilator according to claim 3, wherein the knob is connected to the shaft by a breakable connector that can be broken by torsional or tensile force.

5. The expandable dilator according to claim 2, wherein the knob is rotatably connected to the proximal end of the shaft, the tether is fixed to the knob, and by rotating the knob in a first direction relative to the shaft, the expander is pulled proximal through the lumen, causing the tether to wrap around the knob.

6. The expandable dilator according to any one of claims 1 to 5, wherein the shaft includes a plurality of channels extending longitudinally from the proximal end of the tapered distal tip along the entire length of the shaft.

7. An expandable dilator used with an expandable sheath, A shaft having a tapered distal end and a proximal end, A flexible ring disposed around the tapered distal tip, wherein the flexible ring is configured to be axially movable on the shaft from the tapered distal tip, and the flexible ring has a plurality of protrusions extending radially outward from the outer surface of the flexible ring, An expandable dilator comprising at least one tether, the at least one tether having a distal end fixed to the flexible ring and a proximal end extending axially along the outer surface of the tapered distal tip and entering into an opening in the shaft, the at least one tether extending through the lumen of the shaft, and the proximal end of the at least one tether extending proximal out of the proximal end of the shaft.

8. The expandable dilator according to claim 7, wherein the at least one tether includes two tethers fixed to opposing sides of the flexible ring, and the opening of the shaft includes two openings located on opposing sides of the shaft, with each tether extending into one of the two openings.

9. An expandable dilator used with an expandable sheath, A shaft having a tapered distal end and a body having a proximal end, and a lumen extending longitudinally through the shaft, The shaft comprises at least one expandable member disposed on the main body, each expandable member configured to transition from a compressed state to an expanded state, wherein in the compressed state, the outer diameter of the expandable member is less than or equal to the outer diameter of the main body, and in the expanded state, the outer diameter of the expandable member is greater than the outer diameter of the main body. An expandable dilator wherein, when the shaft is positioned within the expandable sheath, the expandable member is in the compressed state, and the expandable member is moved to the expanded state by moving the shaft distal to the expandable sheath.

10. The expandable dilator according to claim 9, wherein the shaft has at least one recess on the main body, and the expandable member extends over the recess.

11. The expandable dilator according to claim 10, wherein the expandable member is formed from a shape memory material and biased to the expanded form.

12. The expandable dilator according to claim 10, wherein the recess includes a spring, and the expandable member extends over the spring.

13. The expandable dilator according to claim 9, wherein the shaft has at least one rotational marker at its proximal end indicating the circumferential position of the expandable member.

14. The expandable member includes a compressible ring positioned between the tapered distal tip and the body, the shaft includes a tether fixed to the inner wall of the tapered distal tip and extending outward from the proximal end of the shaft through the lumen, the expandable dilator according to claim 9, wherein pulling the tether proximal to the shaft pulls the tapered distal tip toward the distal end of the body, compressing the compressible ring so that the outer diameter of the compressible ring extends radially outward beyond the outer surface of the body, forming a circumferential ridge.

15. It is an expansion system, An expandable dilator according to any one of claims 1 to 14, Equipped with an expandable sheath, An expansion system comprising an expandable sheath having a distal end, a proximal end, a lumen extending between the distal end and the proximal end, and at least one fold portion extending longitudinally from the distal end to the proximal end, each fold portion being defined by a circumferential overlap of the material forming the expandable sheath, the expandable sheath including a distal ring configured to hold the expandable sheath in a compressed state, the distal ring having a long slit positioned above the fold portion, the distal ring being biased into a closed state, and the distal ring being expandable to an expanded state in which the slit expands when the expandable dilator is positioned within the expandable sheath and the expander is located distal to the distal end of the expandable sheath, and the expander of the expandable dilator is pulled proximal, thereby unfolding the fold portion and expanding the inner diameter of the expandable sheath.

Images