Dilator tip design for improved force transmission

Abstract

The dilator comprises a shaft (110, 210) and a stiffening element (120, 220) having a generally cylindrical surface, the stiffening element (120, 220) being connected to the distal end of the shaft (110, 210).

Description

[Technical Field]

[0001] The present invention relates to a dilator having a reinforcing element and a method for manufacturing such a dilator.

[0002] Catheters have been used in a variety of ways to examine or treat blood vessels. Atherosclerosis is a vascular disease manifested by the accumulation of degenerative material along the vessel wall. Affected blood vessels can develop plaques / lesions, which can cause a continuous decrease in luminal diameter and, ultimately, blood flow restriction. Chronic plaque buildup (i.e., composed of a mixture of fatty, fibrous, and / or calcified tissue material) can lead to chronic total occlusions (CTOs).

[0003] However, catheters do not always provide optimal functionality for treating atherosclerosis. There is a need to provide improved methods for treating stenoses or lesions caused by atherosclerotic disease. Thus, there is a need to improve known catheters for treating stenoses or lesions.

[0004] This need is met by the various aspects described herein. Summary of the Invention

[0005] According to a first aspect, a (medical) dilator (also called a dilation catheter, dilator catheter or vasodilator) for insertion into the vascular or cardiovascular system is disclosed.

[0006] The dilator has a dilator shaft, a reinforcing element connected to the distal end of the dilator shaft, and a connecting element. Thus, the reinforcing element is in contact with the distal end of the dilator shaft and the connecting element. The connecting element at least partially surrounds the dilator shaft and / or the reinforcing element. Preferably, the dilator shaft is a braided dilator shaft (i.e., a dilator shaft including a reinforcing braid made, for example, of a polymer, metal, and / or metal alloy).

[0007] Thus, for example, as the dilator shaft moves toward a stenosis (e.g., a CTO), the reinforcing element may come into contact with the stenosis. Because the reinforced element offers increased force resistance compared to a bare dilator shaft (e.g., reduced tendency to bend, break, and / or kink), greater forces may be transmitted to the stenosis by the movement of the dilator shaft. The inventors have found that a particularly advantageous design is provided by separating the functions between the dilator shaft and the reinforcing element. The provided reinforcing element selectively reinforces the distal end of the dilator shaft. Therefore, for example, force transmission and the risk of kinking are reduced when, for example, an asymmetrical stenosis surface applies asymmetrical forces to the reinforcing element. Therefore, direct force transmission from the dilator shaft to the reinforcing element and the stenosis may be facilitated, among other things.

[0008] The reinforcing element may comprise a proximal portion and a distal portion located distally of the proximal portion. The proximal portion may have a (substantially) cylindrical shape. The (substantially) cylindrical proximal portion forms an outer proximal side and an inner proximal side. The proximal portion includes at least one depression, recess, or through-hole, preferably several (i.e., two, three, or more) through-holes. The distal portion may taper distally. Preferably, the reinforcing element comprises a cylindrical proximal portion and a conical distal portion located distally of the cylindrical proximal portion. The distal portion has an outer diameter (e.g., 0.9 to 1.3 mm). The outer diameter at the proximal end of the distal portion may be larger than the outer diameter of the (cylindrical) proximal portion. The outer diameter of the distal portion may taper distally. For example, at the distal end of the distal portion, the outer diameter may be similar to or larger than the outer diameter of the (substantially) cylindrical outer portion. In one embodiment, the reinforcing element may have a distal opening and / or a lumen extending through the proximal and / or distal regions of the reinforcing element. In such cases, a guidewire or another medical device can extend through the lumen. In another embodiment, the proximal and / or distal portions of the reinforcing element do not include a lumen and / or are solid. In such cases, the reinforcing element can be used to dot the stricture. The distal end of the distal portion of the reinforcing element may be rounded and / or obtuse. The distal end of the distal portion of the reinforcing element may form the very distal end of the dilator.

[0009] For example, the dilator shaft and the reinforcing element may comprise different materials and / or may be manufactured separately and subsequently connected. This allows for complete design flexibility with regard to the material selection and manufacturing method of the separate components. For example, the reinforcing element may comprise a material that is harder than the material (or any material) contained in the dilator shaft. A particularly strong connection may be achievable with cylindrical and / or conical reinforcing elements made of metal or metal alloys.

[0010] The dilator according to the first aspect also comprises: This allows the dilator to be used within a catheter system. For example, the dilator may be used with a multi-function catheter system, preferably a peripheral multi-function catheter system.

[0011] The multi-function catheter system comprises a retractable sheath that can sequentially house different internal members such as a dilator, a guidewire and / or a balloon catheter (e.g., a PTA or PTCA catheter). Accordingly, also disclosed is a (peripheral) multi-function catheter system that includes a retractable sheath, preferably a support catheter, that allows for sequential housing of one or more internal members, one of which includes a dilator as described herein.

[0012] The peripheral multifunction catheter system may be an intravascular balloon catheter system supplied with a retractable sheath (e.g., a support catheter), a flexible catheter (e.g., a dilator), and a percutaneous transluminal angioplasty balloon (PTA balloon). The support catheter and dilator are used in series to facilitate lesion access and passage. The peripheral multifunction catheter system allows for variable guidewire support and fluid infusion, as well as an inflatable balloon of adjustable length (e.g., up to 180 mm).

[0013] Such multi-function catheter systems allow for the guidance and support of a guidewire during access to and passage through lesions within the vasculature, and further allow for wire exchange and provide conduits for the delivery of saline or diagnostic contrast agents to facilitate wire passage.

[0014] Therefore, a catheter system, preferably a multi-function catheter system, including the above-described dilator is also disclosed herein. The catheter system may further include a support catheter. The support catheter has a support catheter shaft defining a support catheter lumen capable of receiving the dilator and, optionally, a balloon catheter. The support catheter may have a metal ring in its distal portion. The metal ring may be spaced from the distal end of the support catheter. The dilator shaft may be reinforced, for example, with a metal braid. The support catheter shaft may be reinforced with a metal braid or a metal braid having intertwined pairs of longitudinal wires.

[0015] The use of such a catheter system for crossing a stenosis or chronic total occlusion is also described herein.

[0016] Also described herein is the use of such a catheter system as a pass-through catheter.

[0017] Further described herein are methods of treating stenoses or chronic total occlusions using the dilators and / or catheter systems described above.

[0018] It should be noted that the first embodiment is not only useful for treating stenoses, but may also be useful for a variety of additional intravascular applications. The design according to the first embodiment may be combined with any dilator technology that requires the tip to be durable when longitudinal forces are transmitted. The distal dilator tip preferably includes a polymeric portion and a metallic portion.

[0019] For example, the reinforcing element may extend at least partially distally relative to the distal end of the dilator shaft. The reinforcing element may be adapted to form the most distal portion of the dilator. Thus, the reinforcement may be particularly present at the distal end of the dilator, where the strongest forces are often encountered.

[0020] The dilator may further include a connecting element at least partially surrounding the dilator shaft and / or the reinforcing element. The connecting element may be adapted to connect the dilator shaft and the reinforcing element to each other. For example, the connecting element may form an atraumatic tip of the dilator. For example, the connecting element may comprise a softer and / or more flexible material compared to the material of the dilator shaft and / or the reinforcing element. Thus, the risk of penetration or dissection may be reduced, for example, when contacting a vessel wall.

[0021] In some instances, the shaft may be adapted to be relatively flexible at its most distal portion (compared to more proximal portions of the dilator shaft), for example, to allow the distal tip to be steered away from the vessel wall.

[0022] The reinforcing element may extend at least partially distally relative to the distal end of the connecting element. The reinforcing element may thus form a reinforced tip at the distal dilator end, e.g., to aid in the treatment of a stenosis, and the relatively soft material of the connecting element may continue proximally from the tip. Additionally or alternatively, the connecting element may have an extension that extends to a larger outer diameter compared to the outer diameter (or any diameter) of the reinforcing element. Thus, the delicate, reinforced tip may be surrounded distally and / or radially by the relatively soft material, reducing the risk of damaging the vessel wall. The dilator may have an atraumatic tip (e.g., provided by the connecting element) with locally reinforced strength (e.g., provided by the reinforcing element).

[0023] Exemplary longitudinal extensions from the distal-most portion of the reinforcing element to the proximal-most portion of the connecting element are in the range of 1.0 to 20.0 mm, 2.0 to 10.0 mm, e.g., 6.0 to 7.0 mm. Relatively long extensions may be beneficial in some embodiments, for example, for passing through elongated lesions. However, a drawback is that long extensions may result in reduced maneuverability, potentially greater trauma, and / or increased friction. The specified values may represent an optimal compromise in this regard.

[0024] The portion of the reinforcing element that extends distally relative to the distal end of the connecting element may also be referred to as the distal portion of the reinforcing element.

[0025] In some examples, the reinforcing element may have a longitudinal extension of 0.1 to 5.0 mm, or 0.5 to 3.0 mm. For example, the distal portion of the reinforcing element may have a length (longitudinal extension) of 1.0 mm to 2.0 mm, e.g., 1.5 mm, and the proximal portion of the reinforcing element may have a length (longitudinal extension) of 1.0 mm to 2.0 mm, e.g., 1.5 mm.

[0026] For example, the distal portion of the reinforcing element may assist in atraumatic tip fixation (eg, within a stenosis such as a CTO).

[0027] The connecting element may include a polymer. Polymeric materials may be particularly suitable for providing a relatively soft connecting element that is simultaneously durable, biocompatible, and wear-resistant. Furthermore, polymeric materials may allow for efficient manufacturing methods, such as injection molding. In some examples, the connecting element is injection molded.

[0028] The reinforcing element may include at least one depression, recess, or through-hole. For example, a (generally) cylindrical proximal portion of the reinforcing element, e.g., the inner and / or outer sides of the reinforcing element, may include at least one depression. In some examples, the at least one depression may include at least one through-hole. In other examples, the at least one depression may include at least one partial depression, e.g., a hole that extends only partially to the outer side of the reinforcing element without penetrating the reinforcing element.

[0029] The connecting element may extend at least partially into at least one recess, indentation, or through-hole of the reinforcing element. For example, at least one recess, for example in a (substantially) cylindrical proximal portion of the reinforcing element, may be at least partially filled with the connecting element. This ensures a particularly tight connection between the connecting element and the reinforcing element. In particular, this may result in a tight connection despite longitudinal forces acting on the connecting element and / or the reinforcing element.

[0030] It should be noted that additionally or alternatively, the dilator shaft may comprise at least one recess, e.g., on the (approximately) cylindrical exterior of the dilator shaft. The at least one recess may be designed as described with reference to the at least one recess of the reinforcing element. The connecting element may, for example, extend at least partially into the at least one recess of the dilator shaft in order to make the connection between the connecting element and the dilator shaft particularly strong.

[0031] The connecting element may be tapered distally and / or proximally, which may increase the thickness and thus the stability of the connecting element, for example, at the proximal end of the stiffening element, thereby ensuring a particularly tight connection between the connecting element and the dilator shaft and / or stiffening element. At the same time, the particularly distal tapering may improve the maneuverability of the dilator within the vessel.

[0032] For example, the distal and / or proximal portions of the connecting element may form a wedge shape having an angle of 3° to 30°, or 5° to 25° when viewed in longitudinal cross section.

[0033] The connecting element may extend at least partially around the outer diameter of the dilator shaft and, for example, the outer diameter of the reinforcing element, e.g., the (generally) cylindrical exterior of the reinforcing element, particularly to form a step. For example, at the step, the inner diameter of the connecting element may change so as to provide a transition zone between a portion with a relatively larger inner diameter and a portion with a relatively smaller inner diameter. Thus, the dilator shaft and / or the reinforcing element, e.g., the (generally) cylindrical proximal portion or exterior of the reinforcing element, may be further secured at the transition zone. For example, if the portion with a relatively larger inner diameter is disposed distally and the portion with a relatively smaller inner diameter is disposed proximally, the transition zone may further help resist longitudinal movement of the dilator shaft and / or the reinforcing element relative to the connecting element.

[0034] The (generally) cylindrical proximal portion of the reinforcing element, e.g., the (generally) cylindrical interior of the reinforcing element, may extend, for example, at least partially around the outer diameter of the dilator shaft. For example, the (generally) cylindrical proximal portion of the reinforcing element may be at least partially glued, injection molded, or otherwise connected to the outer surface of the shaft. In some examples, a connecting element may connect the (generally) cylindrical proximal portion of the reinforcing element to the dilator shaft.

[0035] When the (approximately) cylindrical proximal portion of the reinforcing element extends at least partially around the outer diameter of the dilator shaft, the lumen of the dilator shaft may be at least partially free from additional reinforcing elements. For example, a guidewire may be moved within the lumen without being obstructed by the reinforcing element. Furthermore, a low-profile dilator may be provided that can be easily manufactured, for example, by injection molding connecting elements around the dilator shaft and reinforcing elements.

[0036] In some instances, the (generally) cylindrical proximal portion of the reinforcing element extends at least partially along the inner diameter of the dilator shaft. As an example, the (generally) cylindrical proximal portion of the reinforcing element, e.g., forming a (generally) cylindrical exterior, may be glued or otherwise connected to the inner surface of the dilator shaft. In these instances, injection molding of a connecting element around the dilator shaft and reinforcing element may also be used.

[0037] The dilator shaft may have a distal region with an inner diameter that is the same as the inner diameter of the reinforcing element, and a proximal region with the same inner diameter, which may allow for increased functionality in the distal region and provide more space for potential functionality.

[0038] The reinforcing element (e.g., its generally cylindrical exterior) may terminate or abut at a transition region (e.g., a shoulder) between the distal and proximal regions of the dilator shaft. This may further secure the reinforcing element, particularly restricting relative longitudinal movement between the reinforcing element and the dilator shaft. For example, the dilator shaft may include an at least partially radially extending portion, e.g., at the transition region, that can absorb longitudinal forces (similar to those described herein with reference to the step in the connecting element). This may further improve direct force transmission from the dilator shaft to the reinforcing element and then to the stenosis.

[0039] The connecting element may extend at least partially around the distal and proximal regions of the dilator shaft to form a step. The step may thus further enhance fixation of the dilator shaft, the reinforcing element, and the connecting element, particularly in the longitudinal direction. The connecting element may have an olive shape. By olive shape, we mean that the central portion of the connecting element has a larger outer diameter and / or circumference than the distal and proximal portions of the connecting element. Mathematically, the olive shape can be viewed as an ellipsoid (with the long side oriented along the longitudinal axis of the dilator). The olive shape allows for uniform distribution of injected contrast agent over the lesion. The olive shape improves fluid flow around the dilator tip, allowing for a small contrast agent puff for optimal visualization.

[0040] The connecting element may have an outer diameter of 0.5 mm to 3.0 mm, for example 1.0 mm to 2.0 mm, at its central portion.

[0041] The reinforcing element may include or consist of a metal or metal alloy, and thus may provide particularly strong reinforcement. A metal or metal alloy reinforcing element increases the durability, visibility, and ability of the dilator to withstand loads during clinical use without deformation.

[0042] For example, stainless steel, titanium, and / or other biocompatible metals or metal alloys may be used. Also, suitable alloys such as, for example, Nitinol may be used. The dilator shaft may comprise, for example, polyamide (e.g., PA12) or polyether block amide.

[0043] In other examples, the reinforcing element may include a polymer and / or ceramic material, for example, a polymer that has a higher hardness, stiffness, and / or bending resistance, etc., compared to the connecting element material (e.g., the connecting element polymer) and / or the dilator shaft material (e.g., the dilator shaft polymer).

[0044] The reinforcing element may include a distal opening. Thus, there may be functional communication between the outside of the dilator and the inside of the dilator through the reinforcing element. For example, a guidewire may extend from the lumen of the dilator to a region distal to the dilator. This may allow for particular compatibility with dilators requiring such functional communication.

[0045] For example, the dilator (e.g., the dilator shaft) may include an inner lumen for accommodating a guidewire, and the guidewire may travel distally through the lumen such that the guidewire extends out the distal end of the dilator.

[0046] For example, the diameter of the distal opening may be smaller than the inner diameter of the (generally) cylindrical outer surface. Thus, the reinforcing element may include a portion that extends at least partially in the radial direction (e.g., from the relatively narrow opening to the relatively wide (generally) cylindrical outer surface), which may improve longitudinal force transmission.

[0047] In other examples, for example, the distal opening may include a diameter essentially given by the inner diameter of the (approximately) cylindrical outer surface. For example, the reinforcing element may include a shape similar to the open cylinder on its distal side. This may, for example, allow a relatively narrow cylindrical wall to cut into a potential stenosis and aid in anchoring during removal.

[0048] In some instances, the reinforcing element includes a tapered distal end, which may provide increased maneuverability when navigating through a vessel and / or stenosis. The reinforcing element may also improve fixation. For example, the reinforcing element may include an opening at the distal end.

[0049] In some examples, the distal opening may be provided in a tapered region of the reinforcing element, which may be provided distally of the reinforcing element. The tapered region may be followed proximally by, for example, a (generally) cylindrical element. Thus, for example, the reinforcing element may have, for example, a (generally) cylindrical interior with, for example, a constant inner diameter. The (generally) cylindrical element may also have, for example, a (generally) cylindrical exterior with, for example, a constant outer diameter.

[0050] It should be noted that the dilator may also be adapted such that the reinforcing element does not comprise a distal opening, e.g., the reinforcing element may comprise a closed distal surface, particularly in this case, where the dilator may be provided without a lumen and / or guidewire functionality.

[0051] With regard to the term generally cylindrical proximal portion (e.g., surface) of a reinforcing element as outlined herein, it should be noted that a reinforcing element includes not only cylindrical surfaces, but also, for example, cylindrical surfaces with one or more openings, surfaces with a generally cylindrical shape but including local variations (e.g., a generally circular cross-section may be varied by small, e.g., wavy, elevations, or the generally circular cross-section may be approximated by a polygon, etc.) It should be noted that an element described herein as having a generally cylindrical proximal portion may comprise a generally cylindrical inner surface and / or a generally cylindrical outer surface.

[0052] A method of manufacturing a dilator may include providing a dilator shaft and a stiffening element having a (generally) cylindrical proximal portion. The method may further include connecting the stiffening element to a distal end of the dilator shaft.

[0053] In some examples, the method may include injection molding the connecting element such that the connecting element at least partially surrounds the dilator shaft and / or the reinforcing element, which may allow for a particularly efficient method for manufacturing the dilators described herein.

[0054] It should be noted that whenever this specification refers to A "comprising" B, it is understood that the option of A consisting (essentially) of B is also included.

[0055] Furthermore, it should be noted that all steps described herein with respect to a method are understood to also disclose the corresponding expander and features implied by the method. Similarly, all aspects described herein with respect to an expander are understood to also include the corresponding method steps.

[0056] Detailed exemplary embodiments are described below with reference to the following drawings: [Brief explanation of the drawings]

[0057] [Figure 1] FIG. 1 is a longitudinal cross-sectional view of an exemplary dilator. [Figure 2] 10A-10C are longitudinal cross-sectional views of further exemplary dilators. [Figure 3A] 1 is an exemplary reinforcing element. [Figure 3B] 1 is a further exemplary reinforcing element. [Figure 3C] 1 is a further exemplary reinforcing element. [Figure 4A] 10 is a further exemplary dilator. [Figure 4B] 10 is a further exemplary dilator. [Figure 5] 10 illustrates an exemplary embodiment of a manufacturing method for an expander. [Figure 6] 10A-10C illustrate further aspects of the manufacture of an exemplary dilator. [Figure 7A] 10A-10C illustrate further aspects of the manufacture of an exemplary dilator. [Figure 7B] 10A-10C illustrate further aspects of the manufacture of an exemplary dilator. [Figure 8] 10A-10C illustrate further aspects of the manufacture of an exemplary dilator. [Figure 9] 10A-10C illustrate further aspects of the manufacture of an exemplary dilator. [Figure 10] 10A-10C illustrate further aspects of the manufacture of an exemplary dilator. [Figure 11] 1 illustrates an embodiment of a catheter system. [Figure 12] 1 illustrates one embodiment of a support catheter. [Figure 13] 1 illustrates one embodiment of a dilator.

[0058] Although not explicitly stated in all cases, elements described below may generally include features described above with respect to similarly designated elements, and vice versa. Also, not every aspect is repeated with respect to each figure. Thus, the embodiments outlined below may include features described with reference to other embodiments, or more generally, features described above, unless expressly indicated to the contrary.

[0059] FIG. 1 shows a longitudinal cross-sectional view of an exemplary dilator 100 that may include a dilator shaft 110, a stiffening element 120, and a connecting element .

[0060] The dilator shaft 110 has a (generally) cylindrical shape, particularly an elongated cylindrical shape such as a tubular shape. In some examples, the dilator shaft 110 may include a reinforced material. For example, the dilator shaft 110 may include a braided material, such as braided metal. In some examples, the dilator shaft 110 may be fiber reinforced.

[0061] The reinforcing element 120 may include a (approximately) cylindrical element 121 that forms a (approximately) cylindrical surface of the inner and outer configuration of the reinforcing element 120. The cylindrical element 121 may include constant inner and outer diameters. In other examples, variable inner and / or outer diameters may be used. The reinforcing element 120 may further include a closed distal side 122. The thickness of the closed distal side 122 may be the same as or essentially similar to the thickness of the (approximately) cylindrical element 121. The reinforcing element 120 may include a (approximately) cylindrical cap-like shape. As shown in FIG. 1, the distal end of the dilator shaft 110 may contact the inside of the closed distal side 122.

[0062] The (approximately) cylindrical element 121 may include an inner diameter that fits over the outer diameter of the dilator shaft 110 at the distal portion of the dilator shaft 110. The (approximately) cylindrical element 121 may, for example, be clipped onto the outer diameter of the dilator shaft 110, the cylindrical element may be shrink fitted, pressed, and / or connected to the outer diameter of the dilator shaft 110 via an adhesive or the like.

[0063] In some examples, the distal side 122 may comprise a (central) opening (not shown in FIG. 1 ) to provide, for example, fluid communication between the lumen of the dilator shaft 110 and the exterior of the dilator 100, for example, using a guidewire guided inside the (reinforced) dilator shaft 110.

[0064] A connecting element 130 may extend around the proximal portion of the (approximately) cylindrical element 121 (or the (approximately) cylindrical exterior of the (approximately) cylindrical element 121). A distal portion 125 of the (approximately) cylindrical element 121 may not include a connecting element 130. The connecting element 130 may include a variable outer diameter. For example, the outer diameter may decrease, e.g., symmetrically, toward the distal end (e.g., distally tapered portion) and the proximal end (e.g., proximally tapered portion) of the connecting element 130. The outer diameter may include a maximum value at a central portion of the connecting element 130. The connecting element may include or consist essentially of, e.g., a polymer material injection molded onto the reinforcing element 120 and the dilator shaft 110.

[0065] The connecting element 130 may extend along the outer diameter of the dilator shaft 110 and the stiffening element 120. At the proximal end of the stiffening element 120, the connecting element 130 may form a step 131.

[0066] The longitudinal extension of the reinforcing element 120 (or the (approximately) cylindrical element 121 or its inner and / or outer sides) may comprise a value of 1 to 10 times the inner radius of the dilator shaft 110, for example 2 to 8 times, or 3 to 6 times.

[0067] The longitudinal extension of the connecting element 130 may comprise a value between 1 and 10 times, e.g., between 1.5 and 8 times, or between 2 and 5 times, the longitudinal extension of the (approximately) cylindrical element 121 (or its inner and / or outer sides). For example, the longitudinal extension of the distally tapered portion of the connecting element 130 may be about 0.5 to 5 times, e.g., 0.7+3 times, or 0.8 to 2 times, the longitudinal extension of the (approximately) cylindrical element 121 (and / or its inner and / or outer sides). The same dimensions may apply to the proximally tapered portion of the connecting element 130.

[0068] Although shown in FIG. 1, the dilator shaft 110 does not necessarily include a lumen.

[0069] FIG. 2 shows a further example of a dilator 200 comprising a dilator shaft 210, a stiffening element 220, and a connecting element 130.

[0070] The dilator shaft 210 may be (generally) similar to that described with reference to the dilator shaft 110. However, the dilator shaft 210 includes a relatively larger diameter distal region 211 and a relatively smaller diameter proximal region 212. A transition area 213 (e.g., a shoulder) is provided between the distal and proximal regions 211, 212.

[0071] The reinforcing element 220 consists essentially of a (substantially) cylindrical element 221 providing a (substantially) cylindrical interior and a (substantially) cylindrical exterior of the reinforcing element 220. The reinforcing element 220 includes an opening 226 having an inner diameter essentially the same as the inner diameter of the (substantially) cylindrical element 221. In other examples, an opening of smaller diameter or no opening may be provided. The reinforcing element 120 may include a (substantially) ring-like shape.

[0072] The outer diameter of the cylindrical element 221, or its (nearly) cylindrical surface or exterior, abuts the inner diameter of the distal region 211. The distal region 211 may be snapped onto the cylindrical element 221, e.g., the distal region 211 may be shrink fitted and / or attached with an adhesive. The cylindrical element 221 may extend distally from the distal end of the dilator shaft 110. For example, the distal extension may have a value in the range of 0.5 to 5 times or 1 to 3 times the inner radius of the cylindrical exterior 221.

[0073] The connecting element 230 may include a longitudinal extension and an outer diameter that may be (generally) the same as described with reference to the connecting element 130. The connecting element 230 may be injection molded around the dilator shaft 110 and the stiffening element 120. Thus, the inner diameter of the connecting element may follow the outer contours of the dilator shaft 110 and the stiffening element 120. Thus, the connecting element 230 may include a step 231 in the transition area 213. Additionally, the connecting element may include a step 232 at the distal end of the distal portion 211 of the dilator shaft 210. The stiffening element 220 includes a distal portion 225 through which the connecting element 230 does not extend.

[0074] The longitudinal extension of the reinforcing element 210 (or cylindrical element 221 or its cylindrical surface (inner or outer surface)) may comprise the same values relative to the inner diameter of the proximal portion 212 of the dilator shaft 210 as outlined with reference to the inner diameter of the reinforcing element 110 (or cylindrical element 121) and the dilator shaft 110. The longitudinal extension of the connecting element 230 may comprise the same values relative to the longitudinal extension of the reinforcing element 220 (or cylindrical element 221) as outlined with reference to the connecting element 130 relative to the longitudinal extension of the reinforcing element 120 (or (approximately) cylindrical element 121).

[0075] The longitudinal extension of the distal portion 211 of the dilator shaft 210 may comprise a value of 0.2 to 1, 0.2 to 0.9, or 0.3 to 0.8 of the longitudinal extension of the reinforcing element 220 (or cylindrical element 221 (or its inner and / or outer sides)).

[0076] FIG. 3A shows an exemplary reinforcing element 320. The reinforcing element 320 includes a proximal portion 321 and a distal portion 329 located distally of the proximal portion 321. The proximal portion 321 has a (substantially) cylindrical shape. The (substantially) cylindrical proximal portion forms an outer proximal side and an inner proximal side. The proximal portion 321 includes several through holes 323. The distal portion 329 is conical, and preferably, the distal portion tapers distally. The distal portion has an outer diameter. The outer diameter of the distal portion 329 at its proximal end may be larger than the outer diameter of the (cylindrical) proximal portion 321. The outer diameter of the distal portion 329 may taper distally. For example, at the distal end of the distal portion 329, the outer diameter may be similar to or slightly larger than the outer diameter of the (substantially) cylindrical outer portion.

[0077] Distal portion 329 may include an opening 326. The inner diameter of opening 326 may be the same as the inner diameter of (approximately) cylindrical proximal portion 321. Thus, for example, reinforcing element 320 may have a constant inner diameter (lumen). The distal end of distal portion 329 may be rounded (and therefore obtuse).

[0078] For example, the reinforcing element 320 may be attached to the dilator shaft via a connecting element, similar to that described with reference to Figures 1 and 2. Such a connecting element may, for example, extend into the opening 323 and abut (approximately) the proximal portion 321. Such a connecting element may, for example, extend from the proximal direction to the distal direction and terminate at the proximal end of the distal portion 329. The reinforcing element may be made of a metal or metal alloy.

[0079] 3B and 3C show cross-sectional views of the stiffening element of FIG. 3A connected to a connecting element 330 and a dilator shaft 310. Here, it can be seen that the distal portion 329 of the stiffening element has an undercut 340 at its proximal end that provides an anchoring point for the connecting element 330 in addition to the through-hole.

[0080] The longitudinal extension of the reinforcing element from the distal-most portion to the proximal-most portion of the connecting element is within the range of 6.0-7.0 mm. The reinforcing element may have a longitudinal extension of 2.5-3.5 mm. For example, the distal portion of the reinforcing element may have a length (longitudinal extension) of 1.0-2.0 mm and an outer diameter of 0.9-1.3 mm, and the proximal portion of the reinforcing element may have a length (longitudinal extension) of 1.0-2.0 mm and a smaller outer diameter than the distal portion.

[0081] The connecting element has an outer diameter at its intermediate portion that is 1.0 mm to 2.0 mm larger than the outer diameters at its distal and proximal portions. The connecting element has an inner diameter of 0.4 mm to 0.6 mm. The dilator shaft has an inner diameter that is the same as the inner diameter of the reinforcing element.

[0082] In FIG. 3B, the connecting element shows the injection point of the injection molding process, whereas connecting element 330 in FIG. 3C does not have an injection point (e.g., because the polymer is connected to reinforcing element 320 in a different way than by injection molding).

[0083] 4A and 4B show two examples of dilators 400A and 400B. Each of the dilators 400A and 400B includes a dilator shaft 410A, 410B, a reinforcing element 420A, 420B, and a connecting element 430A, 430B. Each of the reinforcing elements 420A and 420B includes a distal portion 425A and 425B, respectively, from which the connecting elements 430A and 430B do not extend. The dilator shafts 410A and 410B of the dilators 400A and 400B may be braided.

[0084] The stiffening element 420B of the dilator 400B includes a recess 427B into which the connecting element 430B extends.

[0085] Reinforcing elements 420A and 420B are preferably the reinforcing elements shown in FIG. 3 and are made from a metal or metal alloy.

[0086] The connecting elements 430A and 430B preferably have an olive shape. The olive shape allows the injected contrast agent to be evenly distributed over the lesion. The connecting elements are made of a polymer. The central portion of the olive shape has a smaller diameter than the distal support catheter end.

[0087] The dilator can be used with and placed in a (multi-function) catheter system such as that described in Figure 11. Once the dilator is in the support catheter, pulling the dilator back (proximally) provides the user with a tactile sensation due to the olive shape, thereby eliminating the need to perform this pulling back step under x-ray (which means less radiation for the patient).

[0088] FIG. 5 shows a cross-sectional view of the upper half of a dilator 500, including a dilator shaft 510 and a reinforcing element 520. The reinforcing element 520 may comprise metal and / or may be manufactured by a machining process, such as turning. The reinforcing element 520 may include a shape similar to that outlined with reference to the reinforcing element 320 shown in FIG. 3. The reinforcing element 520 may, for example, include a (generally) cylindrical (outer) surface 521 that forms the proximal portion of the reinforcing element 520. The reinforcing element 520 may further include a distally tapered distal portion 529 and a proximally tapered intermediate portion 528. By machining, such as turning, the reinforcing element 520 may be manufactured dimensionally precisely and at low cost.

[0089] The connecting element may not be present in the dilator 500. Instead, the distal tip of the dilator 500 may be integrally formed, for example, from a metallic material (e.g., by machining, such as turning a metal workpiece). However, in other examples, the distal tip of the dilator 500 and / or the reinforcing element 520 may also include other materials, such as ceramics or polymers.

[0090] The dilator shaft 510 may comprise, for example, a braided material as described herein.

[0091] The dilator shaft 510 may comprise a proximal portion 512 and a distal portion 511, with the proximal portion 512 comprising a constant but smaller diameter and the distal portion 511 comprising a constant but larger diameter. A transition area 513 may be disposed between the proximal portion 512 and the distal portion 511.

[0092] The exterior of the reinforcing element 520, more specifically the (approximately) cylindrical exterior surface 511, may be attached to the interior of the distal portion 511 by, for example, clipping, heat shrinking, and / or adhesive. The (approximately) cylindrical exterior surface 521 may terminate or abut at a transition area 513.

[0093] The reinforcing element 520 may be at least partially radiopaque. The distal tip of the reinforcing element 520 may be rounded to aid in an atraumatic tip design and to prevent damage to the guidewire, for example, when inserting the dilator over the guidewire.

[0094] 6 illustrates the manufacture of a further exemplary dilator 600 in a cross-sectional view of the top half of the dilator 600. A dilator shaft 610, e.g., braided, that can be adapted as outlined herein, is provided. A radiopaque, e.g., metallic, cannula is disposed on the dilator shaft 610 to form a reinforcing element 620. A connecting element 630 is provided, e.g., by using a polymer coating, as described herein. The connecting element 630 may secure the cannula to the dilator shaft 610. The connecting element 630 may be provided, e.g., by injection molding or welding a section of tubing.

[0095] The geometry of the distal end of the dilator 600 can then be formed, for example, by a suitable counterpart forming mold 601. Here, the connecting element 630 may help form rounded edges to form an atraumatic tip. By using the mold 601, dimensional accuracy, consistent shape across multiple samples, and low cost can be achieved.

[0096] 7 illustrates, in cross-section, the manufacture of another example of a dilator 700. In step 700A, a dilator shaft 710 is provided having a proximal portion 711 and a distal portion 712. The distal portion 712 is expanded using a shaping element 701, for example, to form a distally tapered portion 714 (distally disposed) and a proximally tapered portion 713 (proximally disposed).

[0097] Once the molding element is removed, in step 700B, the reinforcing element 720 is inserted into the dilator shaft 710 such that the reinforcing element 720 comprises a distal portion 725. The shaft 710 may not extend over the distal portion 725. The reinforcing element 720 may comprise a metal. The reinforcing element 720 may be manufactured by lathing. However, the reinforcing element 720 may alternatively comprise other materials, such as ceramic or polymer. The connection between the reinforcing element 720 and the dilator shaft 710 may be effected, for example, by shrink-fitting the dilator shaft 710 to the reinforcing element 720 and / or by heating the dilator shaft 710.

[0098] FIG. 8 illustrates a further embodiment for manufacturing a dilator 800 as described herein. Specifically, FIG. 8 illustrates a longitudinal cross section of the top half of the dilator 800. A dilator shaft 810 may be provided. A reinforcing element 820 may be provided at least partially on the outer diameter of the dilator shaft 810. The reinforcing element 820 may be provided by molding or injection molding. A connecting element 801 may then be provided, for example, by molding or injection molding. A mold, such as a tip forming tool, may be used to thermally form the desired tip shape, similar to that described with reference to FIG. 6.

[0099] FIG. 9 illustrates a further embodiment of manufacturing a reinforcing element 920 described herein. The reinforcing element 920 may include a shape such that it can be used without a connecting element on the dilator shaft of a dilator. The reinforcing element may be manufactured by drilling, eroding, laser cutting, etc. 901 a cylindrical opening into a bulk part. For example, the bulk part may be manufactured by injection molding, casting, machining, etc., and then the cylindrical opening may be created. For example, the opening may be in the form of a longitudinal through-hole having a uniform inner diameter. However, varying diameters are also possible. For example, a first inner diameter may be drilled, eroded, laser cut, etc. on the distal side, and a second inner diameter may similarly be provided on the proximal side. The reinforcing element 920 may be attached to the dilator shaft of a dilator described herein, for example, by adhesive, pressing, etc.

[0100] FIG. 10 shows a further example for manufacturing a dilator 1000 in a cross-sectional view of the upper half of the dilator 1000. A preformed, e.g., molded, part 1030 may be fitted to the dilator shaft 1010. A reinforcing element 1020, such as a (metal) band, which may be a radiopaque marker band, may be crimped onto the distal portion of the dilator shaft 1010 and partially overlap the preformed part 1030. The reinforcing element 1020 may thus secure the preformed part 1030 onto the dilator shaft 1010. The preformed part 1030 may provide the functionality described herein with reference to the connecting element, and the preformed part 1030 may generally include the same outer diameter and longitudinal extension. However, in this example, the part 1030 may not have a connecting function. Instead, the part 1030 may also be connected to the dilator shaft 1010 by crimping the reinforcing element 1020 into the dilator shaft 1010.

[0101] FIG. 11 shows a catheter system 1, preferably a multi-function catheter system, comprising a support catheter or retractable sheath 2, a dilator 3 having a distal dilator end 32, and, optionally, a (locking) handle 4. The support catheter shaft 23 defines a support catheter lumen 26 capable of receiving the dilator 3. The dilator 3 is thus disposed within the support catheter lumen 26 of the support catheter 2. The dilator shaft and / or the support catheter shaft may be reinforced, for example, with a metal braid or a metal braid having intertwined pairs of longitudinal wires. The support catheter may have a straight-edged distal end (allowing for greater pushability and avoiding wobble). The support catheter may have a radiopaque marker at its distal end, preferably in the form of a metal (alloy) ring or metal (alloy) cap covering the distal support catheter end and having a distal opening and rounded edges.

[0102] FIG. 12 shows a support catheter 2. The support catheter 2 has a distal support catheter end 21, a proximal support catheter end 24, and a support catheter shaft 23 extending between the support catheter distal end 21 and the support catheter proximal end 24. The proximal support catheter end 24 can include or be connected to a locking handle 4. The locking handle may have a gripping surface and an ergonomic design. The support catheter may include a manifold connected to the locking handle 4. The support catheter 2 may include one or more support catheter ports 27, preferably one or more ports for fluid media, such as a flushing port, inflation and / or deflation ports. The distal support catheter end 21 is the end that is inserted into the human or animal body. The proximal outer catheter end 24 is the end that is manipulated by an operator, particularly a physician.

[0103] FIG. 13 shows a dilator 3 having a distal dilator end 32, a proximal dilator end 34, and a dilator shaft 33 extending between the distal dilator end 32 and the proximal dilator end 34. The proximal dilator end 34 may include a dilator manifold 35. The dilator manifold may have a shape that allows an operator, e.g., a physician, to easily use it to manipulate the dilator. The dilator may include one or more dilator lumens (not visible). Preferably, the dilator includes a first lumen for receiving a guidewire and a second lumen for receiving a fluid medium, e.g., a contrast agent. However, the dilator may have only one lumen, allowing for simultaneous injection of a guidewire and a contrast agent. The dilator, preferably the dilator manifold 35, may include a dilator port 36 for injecting a fluid medium (e.g., a contrast agent) into at least one of the dilator lumens.

[0104] The dilator shown in Figures 11 to 13 is one of the dilators described herein, in particular the dilator described in Figures 1 to 4A / 4B.

Claims

1. Shaft (110, 210) and Reinforcement elements (120, 220, 320), Connecting elements (130, 230), An expander (100, 200) comprising or consisting thereof, Expander (100, 200) wherein the reinforcing elements (120, 220, 320) are connected to the distal ends of the shafts (110, 210), the connecting elements (130, 230) at least partially surround the shafts (110, 210) and / or the reinforcing elements (120, 220, 320), the connecting elements (130, 230) extend into at least one recess, recess or through hole of the reinforcing elements (120, 220, 320), the connecting elements (130, 230, 320) are made of polymer, and the reinforcing elements (120, 220, 320) are made of metal or a metal alloy.

2. The expander according to claim 1, wherein the reinforcing element (120, 220, 320) comprises a proximal portion (321) and a conical distal portion (329) located distal to the proximal portion (321), preferably a cylindrical proximal portion (321) and a conical distal portion (329) located distal to the cylindrical proximal portion (321).

3. The expander (100, 200) according to claim 2, wherein the reinforcing elements (120, 220, 320) extend at least partially distally (125, 225) from the distal end of the connecting elements (130, 230).

4. The expander according to claim 2 or 3, wherein the connecting elements (130, 230, 320) have an olive shape.

5. The expander according to claim 2 or 3, wherein the reinforcing elements (120, 220, 320) have a lumen.

6. The expander according to claim 2 or 3, wherein the connecting elements (130, 230) extend at least partially around the outer diameter of the shaft (110, 210) and the proximal portion (321) and / or the distal portion (329) of the reinforcing elements (110, 120, 320), particularly to form a step (131, 231).

7. The expander according to any one of claims 1 to 3, wherein the reinforcing elements (120, 220, 320) extend at least partially around the outer diameter of the shaft (110).

8. The expander according to any one of claims 1 to 3, wherein the reinforcing elements (120, 220, 320) extend at least partially along the inner diameter of the shaft (210).

9. The expander according to any one of claims 1 to 3, wherein the shaft (210) comprises a distal region (211) and a proximal region (212), and the distal region (211) has a larger diameter than the proximal region (212).

10. The expander according to claim 9, wherein the proximal portion (321) of the reinforcing element (110, 120, 320) terminates or abuts in the transition area (213) between the distal region (211) and the proximal region (212).

11. The expander according to claim 1 or 3, wherein the reinforcing element (120, 220, 320) comprises a proximal portion (321), and the proximal portion (321) comprises at least one recess, concave or through hole.

12. The expander according to any one of claims 1 to 3, wherein the reinforcing elements (220, 320) are provided with distal openings (226, 326).

13. The expander according to any one of claims 1 to 3, wherein the reinforcing element (320) has a distal end (329) that tapers distally.

14. The expander according to any one of claims 1 to 3, wherein the shaft is provided with a reinforcing braid.

15. A catheter system comprising a dilator according to any one of claims 1 to 3, preferably a multifunctional catheter system.

16. The catheter system according to claim 15, further comprising a support catheter having a support catheter shaft 23 that defines a support catheter lumen 26 capable of receiving the dilator.

17. The catheter system according to claim 15, wherein the support catheter has a metal ring at its distal portion.

18. The catheter system according to claim 15, wherein the support catheter shaft is reinforced with a metal braid or a metal braid having intertwined pairs of longitudinal wires.

19. A catheter system according to claim 15 for use in passing through a stenosis or chronic total occlusion.

20. Preferably, a method for manufacturing an expander (100, 200) according to any one of claims 1 to 3, By providing shafts (110, 210) and reinforcing elements (120, 220), Connecting the reinforcing elements (120, 220) to the distal end of the shaft (110, 210) by injection molding or adhesive, such that the connecting elements (130, 230) at least partially surround the shaft (110, 210) and / or the reinforcing elements (120, 220, 320), wherein the reinforcing elements (120, 220, 320) comprise a cylindrical proximal portion (321) and a conical distal portion (329), the connecting elements (130, 230, 320) are made of polymer, and the reinforcing elements (120, 220, 320) are made of metal or a metal alloy. A method that includes this.

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