Endoscopic catheter equipment

Abstract

An apparatus may include a catheter and a support tube. The catheter includes a lumen extending therethrough. The catheter may be sized and shaped to extend through an endoscope shaft and into a target tissue in a living body. The lumen may be sized and shaped to receive a puncture device therethrough. The catheter includes a first catheter portion distal to a second catheter portion. The first catheter portion and the second catheter portion are constructed of different materials. The first catheter portion has a flexible, curved distal end. A tube is secured around an outer surface of the distal end of the first catheter portion and an outer surface of the distal end of the second catheter portion.

Description

[0001] Priority declaration

[0002] This disclosure claims priority to U.S. Provisional Patent Application Serial No. 62 / 928,082, filed on December 30, 2019; the disclosure of which is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to endoscopic catheter devices, and more particularly to microcatheters for endoscopic ultrasonic access procedures. Background Art

[0004] Endoscopic ultrasound (EUS) access procedures are frequently used to gain access to patient anatomical structures such as the bile duct, pancreatic duct, or pancreatic fluid collection in order to, for example, insert stents and remove blockages. These procedures typically rely on curved (J-tip) catheters that can be rotated so that the curved distal end of the catheter is oriented in the desired direction, for example, down the lumen of a bile duct to deliver a guidewire to a target site within the body. However, existing catheters may exhibit limitations that make them unsuitable for certain applications. For example, some catheters may be susceptible to extrusion along their length due to insufficient column strength for effective puncture. Summary of the invention

[0005] The present disclosure relates to an apparatus that may include a catheter. The catheter includes a lumen extending therethrough. The catheter may be sized and shaped to extend through an endoscope shaft to a target tissue in a living body. The lumen may be sized and shaped to receive a puncture device therethrough. The catheter includes a first catheter portion distal to a second catheter portion. The first catheter portion and the second catheter portion are made of different materials. The first catheter portion has a flexible, curved distal end.

[0006] In one embodiment, the device may further include a support tube, wherein the support tube is fixed around the outer surface of the proximal end of the first catheter portion and the outer surface of the distal end of the second catheter portion.

[0007] In one embodiment, the first catheter portion is constructed of a braided polymer and the second catheter portion is constructed of Nitinol.

[0008] In one embodiment, the support tube is formed from flexible laser cut steel.

[0009] In an embodiment, the apparatus further comprises an electrical insulation layer surrounding the support tube.

[0010] In one embodiment, the first conduit portion and the second conduit portion meet at a butt joint and are joined to the support pipe.

[0011] In an embodiment, the device further comprises an echogenic material on the flexible distal end and / or the support tube.

[0012] In one embodiment, the echogenic material is a coating comprising particles suspended in an acoustically transparent material.

[0013] In one embodiment, the echogenic material is a wire or polymer that is coiled or braided at the distal end.

[0014] In one embodiment, the device further includes a puncture device sized and shaped to extend through the lumen of the catheter and to extend a curved distal end distally, wherein the puncture device straightens the curved distal end as the puncture device extends through the curved distal end so that when the puncture device punctures the access hole in the target tissue, the straightened distal end follows the puncture device into the access hole.

[0015] In one embodiment, the apparatus further comprises an electrosurgical sheath slidable longitudinally along the exterior of the catheter and support tube, the electrosurgical sheath having an electrosurgical tip for electrosurgically dilating the access hole when the electrosurgical sheath is slid over the curved distal end and an electrical current is applied.

[0016] In an embodiment, the proximal end of the first catheter portion has a reduced outer diameter relative to an outer diameter of the distal end of the first catheter portion.

[0017] In one embodiment, the outer diameter of the second catheter portion is substantially equal to the reduced outer diameter of the proximal end of the first catheter portion.

[0018] In one embodiment, the outer diameter of the support tube is substantially equal to the outer diameter of the distal end of the first catheter portion.

[0019] In one embodiment, the device further includes a polymer that surrounds one of the outer surface of the proximal end of the first catheter portion and the outer surface of the distal end of the second catheter portion when the outer surface of the proximal end of the first catheter portion and the outer surface of the distal end of the second catheter portion are not aligned.

[0020] In an embodiment, an edge of one of an inner surface of the proximal end of the first catheter portion and an inner surface of the distal end of the second catheter portion is chamfered.

[0021] In one embodiment, the apparatus further comprises a metal hypotube surrounding an outer surface of the first catheter portion proximate the curved distal end.

[0022] In one embodiment, the device may further include a polymer having a first diameter surrounding an outer surface of the proximal end of the first catheter portion, and a polymer having a second diameter surrounding an outer surface of the distal end of the second catheter portion. The second diameter is larger than the first diameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 An endoscopic access assembly for use in EUS-guided surgery is shown.

[0024] Figure 2 Shows Figure 1 The endoscope enters the distal end of the catheter of the assembly.

[0025] Figure 3 Shows Figure 2 Cross-sectional view of the catheter.

[0026] Figure 4 A catheter with echogenic material on the outer surface of the J-shaped tip is shown.

[0027] Figure 5 A catheter is shown with a polymer portion having a varying outer diameter.

[0028] Figure 6 A catheter with an extended hypotube is shown. DETAILED DESCRIPTION

[0029] The present disclosure may be further understood with reference to the following description and accompanying drawings, in which similar elements are labeled the same. Exemplary embodiments describe endoscopic catheter devices, particularly microcatheters used during EUS-guided procedures (e.g., pancreaticobiliary access procedures), having high column strength that allows for smooth puncture when a pointed puncture tip (sharp) is extended out of the lumen of the catheter. Some embodiments have electrical insulation and heat resistance for electrosurgical dilation. Each of the embodiments described may have echogenic material added to improve the field of view of the device under ultrasound guidance during surgery.

[0030] Figure 1 FIG. 1 shows an endoscopic access assembly 100 for use in an EUS-guided procedure according to an exemplary embodiment. The endoscopic access assembly 100 has a microcatheter 200, which will be described below with respect to Figure 3 The microcatheter 200 has a flexible tip 202. In an exemplary embodiment, as Figure 2 As shown, the tip 202 can be configured to present a curved shape (e.g., a J-shaped tip) (in an unstressed state). The curved shape can take an arc shape, a J shape, or other shapes. In an exemplary embodiment, the curved shape is a J shape.

[0031] The microcatheter 200 further has an outer support tube 210, which will be described in more detail below. Figure 1In the embodiment of the present invention, a puncture element having a rigid, sharp tip (tip) 102 extends through a lumen and extends out of the tip 202 of the microcatheter 200. The tip 102 is generally straight in an unstressed state, and thus, when the tip 102 is advanced through the lumen of the microcatheter 200 to the distal end of the tip 202, the tip 202 is straightened. In this straightened configuration, i.e., the tip 102 extends out of the distal end of the J-tip 202 (but before the tip 102 and the tip 202 are extended distally out of the electrosurgical sheath 104), the combined tip / J-tip is advanced (e.g., through an endoscope) to a target location in the body. The user can then puncture the target site in the anatomy to a certain depth with the tip 102, while advancing the tip 202 with the tip 102, so that the tip 202 follows the tip 102 through the tissue to the target location (e.g., through the wall of the small intestine into the target bile duct). When the tip 202 is in the desired position in the bile duct, the tip 102 is withdrawn from the tip 202, allowing the tip 202 to return to its curved shape. The tip 202 can then be rotated to the desired direction so that the distal hook of the tip 202 aligns the distal opening of the tip 202 with the direction in which the guidewire is to be advanced into the bile duct.

[0032] The guide wire is then inserted through the microcatheter 200 and the tip 202 so as to extend distally from the tip 202 and further moved into the bile duct until the desired length of the guide wire is received in the bile duct. Once the guide wire is positioned as desired, the flexible electrosurgical sheath 104 with the electrosurgical tip 106 is advanced over the catheter 200 and the tip 202, while applying a radiofrequency current from the electrosurgical tip 106 through the tissue to expand the access hole formed by the tip 102 and the tip 202. This ensures the integrity of these openings, after which the catheter 200 can be withdrawn from the body, leaving the guide wire in the bile duct. A stent or other therapeutic and / or diagnostic device can then be inserted into the target site in the bile duct through the access hole on the guide wire, as understood by those skilled in the art.

[0033] Figure 3 A cross-sectional view of the catheter 200 is shown in more detail. The catheter 200 exhibits increased column strength, which is based in part on the structure of the outer support tube 210 and the metal hypotube portion 206, whose strength and flexibility will be described in detail below. The catheter 200 also exhibits higher heat resistance, radiation protection, rotation control, water tightness and flexibility.

[0034] The catheter 200 includes a two-part catheter shaft having a distal braided polymer portion 204 including a tip 202, the proximal end of the polymer portion 204 butted against a hypotube 206 proximal to the polymer portion 204. The proximal end of the polymer 204 and the distal end of the hypotube 206 meet at a butt 208. An outer support tube 210 is affixed to the outer diameter of the polymer portion 204 and the hypotube 206, a portion of which covers and provides support for the joint 208 between the tube portions. The outer support tube 210 can extend the entire length of the catheter 200.

[0035] As will be appreciated by those skilled in the art, the polymer used for the braided polymer portion 204 is selected to have a relatively high melting point (to prevent melting or deformation during electrosurgical expansion), shape memory (to allow the J-shaped tip to naturally return to a curved shape) and good dielectric strength (to electrically insulate the internal braid in the exposed tip). The polymer may be, for example, Arnitel, Pebax, nylon, polyurethane, etc. Some polymers may be more suitable for high temperature applications, while other polymers may be more suitable for low temperature applications. The braid within the polymer may be a round wire or ribbon made of thin stainless steel, steel, nickel titanium alloy, a more radiopaque material such as tungsten or platinum, or other metals. The braid may also include high-strength non-metallic braid reinforcements such as liquid crystal polymers (LCP), PEEK, etc. The braided polymer may have a thinnest inner layer made of, for example, PTFE, FEP, HDPE or other polymers, and a lubricating additive may be added to provide a braided surface and reduce friction, thereby reducing the force required to remove the tip therefrom and / or insert a guidewire therein.

[0036] The tip 202 of the polymer portion 204 of this embodiment can be set into a J-shape by heat. As will be appreciated by those skilled in the art, after the J-shaped tip 202 enters the target anatomical structure, the J-shaped tip 202 is rotated to face the distal opening of the tip 202 cavity, and the curved shape allows the guidewire to be inserted into the target cavity (e.g., bile duct) in the desired direction. The braid provides durability, torsion resistance, torque transmission, and tensile strength.

[0037] In addition, the distal end of the braided polymer portion 204 of the tapered tip 202 can be beveled or tapered to reduce the force required for penetrating the target tissue during initial puncture. The tip 202 can have a short, unbraided portion at its distal end to achieve a cone. The unbraided portion can be a different material suitable for bearing compressive forces during the tip entry process, such as a harder material, such as vestamid nylon. The tip 202 can also have a radiopaque (RO) marker 214 at the distal end of the braid to help terminate the braid and / or provide radiopaque (e.g., more easily see the marker 214 via X-rays to see the tip 202).

[0038] The metal hypotube 206 can be made of, for example, nickel-titanium alloy to provide flexibility, column strength and torque transmission. The distal end of the hypotube 206 (joining the polymer portion 204) can be chamfered on its inner diameter to prevent the guidewire from sliding along the inner edge, as will be understood by those skilled in the art.

[0039] The outer support tube 210 in this embodiment can be made of laser cut steel to provide flexibility, although other ways of making the support tube 210 flexible, such as mechanical cutting or winding, can be used. The steel material of the support tube 210 is less prone to cracking than nickel-titanium alloy, improving durability. The outer support tube 210 can have a short section that is not laser cut and is located at the joint 208 to prevent bending at the joint 208, which may also cause the guidewire to slip at the butt joint 208 of the polymer 204 and the hypotube 206. To further prevent bending, the joint 208 between the polymer 204 and the hypotube 206 can be located far enough away from the distal tip so that the joint 208 does not enter the target anatomical structure through the tissue opening so that it can always be supported by the electrosurgical sheath 104.

[0040] The support tube 210 is fixed to the outer diameter of the proximal end of the polymer 204 and the distal end of the hypotube 206 and provides additional column strength, torsional resistance, torsional rigidity and twist resistance to the polymer portion 204. The support tube 210 can be fixed to the polymer 204 and the hypotube 206 via, for example, glue, which can also provide a chamfer or taper at the distal end of the hypotube 206 to facilitate smoother entry into the tissue when the tip is used for initial puncture. The support tube 210 is covered with a thin layer of electrical insulation 212 to prevent the electrosurgical expansion tip 106 from burning non-target tissue near the support tube 210 when it is advanced on the support tube 210.

[0041] In another embodiment, the catheter 200 can form part of a cold device that provides puncture and directional guidewire access, but does not provide cautery or electrosurgical dilation. In this embodiment, the microcatheter does not need to be heat-resistant or electrically insulating. Therefore, the braided polymer can be made of arnitel, Pebax, PEEK or other materials. In this embodiment, electrical insulation is not necessary. The cold device can be used, for example, for convergent EUS access procedures, where a guidewire is fed into the bile duct and out of the papilla. If used for transmembrane stent surgery, it may be necessary to replace it to introduce an additional dilation tool, or a taper can be added to the electrosurgical tip 106 for cold dilation.

[0042] In another embodiment, the tip 202 of the catheter 200 is made long and flexible enough to pass through the bile duct and advance upward or through the stenosis. As will be appreciated by those skilled in the art, having the tip 202 close to the stenosis provides additional support and ease of use when the guidewire is advanced through the stenosis during a rendezvous procedure. In some surgeries, a stent may be placed on the guidewire. The laser cut steel design provides additional flexibility for passing through the pancreaticobiliary tree. Permanent changes in the shape of the microcatheter 200 as it passes along the bile duct are acceptable because the shape change is only detrimental to rotation and puncture, which is already accomplished when using this disposable device.

[0043] The exemplary embodiments also describe a microcatheter to which echogenic material has been added for improved visualization via ultrasound during a procedure.Echogenic material may be added to any of the embodiments described herein.

[0044] Figure 4 A catheter 300 is shown having an echogenic material 302 on the outer surface of a J-shaped tip. In this embodiment, the echogenic material can be a coating of rigid sound-emitting particles suspended in a soft, sound-transmissive material. Alternatively, the echogenic material can be a wire or polymer coiled or braided on the J-shaped tip. The wire can be, for example, nickel-titanium alloy, steel, tungsten, or other material, and can be radiopaque or echogenic to increase the transmissivity of the catheter 300. The wire can be round or ribbon-shaped and can be, for example, one to five thousandths of an inch in diameter. When the echogenic material 302 is a wire or coil on the tip surface, an expanded electrical insulator 304 can cover both the outer support tube and the sound-emitting material 302. However, if the catheter 300 is a cold device, electrical insulation is not necessary.

[0045] The exemplary embodiments also describe a microcatheter that, despite including a laser cut support tube thereon, has a relatively small outer diameter. A microcatheter with a reduced outer diameter may be desirable by a physician to reduce the size of the puncture hole created in the tissue.

[0046] Figure 5 A catheter 400 is shown having a polymer portion 402 with different outer diameters. The catheter 400 has a larger outer diameter at the curved distal end, comparable to the previously described embodiments, and a smaller outer diameter at the proximal end surrounded by an outer support tube 408. The outer support tube 408 can have a thickness that substantially fills the difference between the curved distal end diameter and the smaller proximal end diameter, making the catheter 400 have a substantially consistent outer diameter from the support tube portion to the distal tip, although such a consistent diameter is not required.

[0047] The hypotube 404 has a cross-sectional area substantially similar to the proximal end of the reduced diameter of the polymer portion 402, and is connected to the polymer portion at the joint 406, similar to the previously described embodiments. The support tube 408 protects the joint 406 in a manner similar to that described in the previous embodiments. The reduced cross-sectional area allows for more precise puncture of anatomical structures. The braided wires in the polymer portion 402 may be partially exposed at the proximal end of the polymer portion 402, and these exposed braided wires will be covered by the support tube 408 and / or the electrical insulation 412. The catheter 400 may also include an echogenic material 410 covered by the electrical insulation 412 for electrosurgical dilation applications.

[0048] In another embodiment, the inner and outer diameters of the polymer portion and the hypotube may not be precisely aligned. If such an inexact inner diameter alignment is used, the portion with the smaller diameter may be chamfered or tapered to prevent slippage of an item inserted therein (e.g., a guidewire). Additionally, when the outer diameters are not aligned, slippage may be prevented by adding a layer of other material to the polymer or hypotube (whichever is smaller) to fill the gap between it and the support tube. Such a material may be, for example, a heat shrink agent.

[0049] In another embodiment, the outer support tube can be eliminated from the design, with the hypotube taking over its function. This embodiment is desirable for applications where a less flexible or smaller device is acceptable, such as urology applications. If used on a less tortuous path, or in applications where the device is overall smaller, it may be able to rotate easily without excessive agitation.

[0050] Figure 6 A catheter 500 is shown having an extended hypotube 504. The catheter 500 includes a polymer portion 502, wherein Figure 4 Similarly, polymer portion 502 has a larger outer diameter at the curved distal end and a smaller outer diameter at the proximal end. However, the smaller diameter proximal end is not surrounded by an outer support tube, but by a hypotube 504. Alternatively, the polymer may have a constant outer diameter, such as Figure 4 As shown. In this embodiment, the polymer portion 502 extends over the entire length of the catheter, albeit with a smaller diameter, and the hypotube 504 provides support along the length of the catheter until the joint 506 where the hypotube 504 terminates. The polymer 502 and hypotube 504 can be attached with an adhesive, polymer reflow soldering, or other means. The joint 506 can be located more distally than in the previously described embodiments. For example, the hypotube 504 can extend into the puncture site.

[0051] In another embodiment, the metal hypotube can be eliminated from the design. In this embodiment, the polymer runs the length of the catheter, with the outer support tube extending a greater length proximally. This embodiment may be particularly useful for applications where the device length is shorter, such as urology or pulmonary applications. In these cases, the axial compression of the laser-cut support tube and polymer will be multiplied over the shorter total length, resulting in less overall axial compression during the puncture.

[0052] Those skilled in the art will appreciate that changes may be made to the above-described embodiments without departing from the inventive concept thereof. It should be further understood that structural features and methods associated with one of the embodiments may be incorporated into other embodiments. Therefore, it is understood that the present invention is not limited to the specific embodiments disclosed, but also encompasses modifications within the scope of the invention as defined by the appended claims.

Claims

1. Equipment, the equipment include: a catheter including a lumen extending therethrough, the catheter being sized and shaped to extend through an endoscope shaft to a target tissue in vivo, the lumen being sized and shaped to receive a puncture device therethrough, the catheter including a first catheter portion distal to a second catheter portion, the first catheter portion and the second catheter portion being constructed of different materials, the first catheter portion having a flexible distal end, the flexible distal end being biased to assume a predetermined curvature in an unstressed state; as well as An electrosurgical sheath is slidable longitudinally along the exterior of the catheter, the electrosurgical sheath having an electrosurgical tip for electrosurgically dilating the access hole when the electrosurgical sheath is slid over the distal end and an electrical current is applied.

2. The apparatus of claim 1, wherein the first catheter portion is comprised of a braided polymer and the second catheter portion is comprised of nitinol.

3. The device according to any one of claims 1 to 2, further comprising: include: A support tube is fixed around an outer surface of the proximal end of the first catheter portion and an outer surface of the distal end of the second catheter portion.

4. The device according to claim 3, further comprising: include: An electrically insulating layer surrounds the support tube.

5. The apparatus of claim 3, wherein the first conduit portion and the second conduit portion meet at a joint and are coupled to the support tube.

6. The device of claim 3, further comprising: include: Echogenic material on the flexible distal end and / or the support tube.

7. The apparatus of claim 6, wherein the echogenic material is a coating comprising particles suspended in an acoustically transparent material.

8. The device of claim 6, wherein the echogenic material is a wire or polymer that is coiled or braided at the distal end.

9. The device of claim 1, further comprising: include: A puncture device is sized and shaped to extend through the lumen of the catheter and to extend distally out of the distal end, and when the puncture device extends through the distal end, the puncture device straightens the distal end so that when the puncture device punctures an access hole in the target tissue, the straightened distal end follows the puncture device into the access hole.

10. The apparatus of claim 3, wherein the electrosurgical sheath is slidable longitudinally along the exterior of the support tube.

11. The apparatus of claim 3, wherein the proximal end of the first catheter portion has a reduced outer diameter relative to an outer diameter of the distal end of the first catheter portion.

12. The apparatus of claim 11, wherein the outer diameter of the second catheter portion is substantially equal to the reduced outer diameter of the proximal end of the first catheter portion, and wherein the outer diameter of the support tube is substantially equal to the outer diameter of the distal end of the first catheter portion.

13. The device of claim 1, further comprising: include: A polymer surrounds one of the outer surface of the proximal end of the first catheter portion and the outer surface of the distal end of the second catheter portion when the outer surface of the proximal end of the first catheter portion and the outer surface of the distal end of the second catheter portion are not aligned.

14. The apparatus of claim 1, wherein an edge of one of an inner surface of the proximal end of the first catheter portion and an inner surface of the distal end of the second catheter portion is chamfered.

15. The device of claim 1, further comprising: include: A metal hypotube surrounds the outer surface of the first catheter portion proximate the curved distal end.

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