Bending-adjustable reducing ureter guiding sheath

Abstract

A cannula comprises a large-diameter section and a small-diameter section, the large-diameter section is connected with the small-diameter section, the large-diameter section is connected to the near end of the small-diameter section, a large channel is defined in the large-diameter section, a small channel is defined in the small-diameter section, and the large-diameter section is connected to the near end of the small-diameter section. The diameter of the large channel is larger than that of the small channel so as to accelerate fluid passing, and at least part of the small-diameter section is a flexible pipe section. The ureter guiding sheath further comprises at least one pull wire, the pull wire extends in the longitudinal direction and is arranged in the wall of the cannula, the far end of the pull wire is fixedly connected to the head end of the small-diameter section, and the pull wire is controlled by the operation part to drive the small-diameter section to longitudinally move relative to the large-diameter section so as to drive the flexible pipe section to deflect.

Description

Technical Field

[0001] This utility model relates to a ureter sheath, specifically a variable diameter ureter guiding sheath. Background Technology

[0002] Currently, natural orifice pyelolithotomy primarily utilizes a ureteral guiding sheath and a flexible ureteroscope. The ureteral guiding sheath is inserted into the urinary tract through the patient's urethra to establish an effective channel for the smooth entry and exit of surgical instruments such as the flexible ureteroscope for the lithotomy procedure. During the procedure, current techniques involve introducing water into the working channel of the endoscope and draining it from the gap between the endoscope and the sheath, creating a negative pressure suction to promptly remove the laser-dislodged stone fragments. However, due to the small gap between the endoscope and the sheath, stone fragments can easily become lodged between them. Therefore, the endoscope needs to be withdrawn from the sheath to remove the fragments promptly. This requires repeated insertion and withdrawal of the endoscope during the procedure, making the entire process quite cumbersome. Utility Model Content

[0003] This invention provides an adjustable-diameter ureteral guide sheath, comprising an operating part and a cannula suitable for insertion into the ureter. The operating part is connected to the proximal end of the cannula, and the cannula defines a central channel extending from the proximal end to the distal end. The operating part defines an inlet communicating with the central channel of the cannula, and the inlet is provided with a sealing valve to allow instruments to pass through the central channel in a sealed manner. The operating part has a negative pressure connector communicating with the central channel. The cannula includes a large-diameter section and a small-diameter section, with the large-diameter section connected to the proximal end of the small-diameter section. The large-diameter section defines a large channel, and the small-diameter section defines a small channel. The diameter of the large channel is larger than the diameter of the small channel to accelerate fluid passage. At least a portion of the small-diameter section is a flexible segment. The ureteral guide sheath also includes at least one pull wire, which extends longitudinally and is disposed within the cannula wall. The distal end of the pull wire is fixedly connected to the head end of the small-diameter section. When the pull wire moves longitudinally relative to the main body section, it causes the flexible segment to deflect.

[0004] In some implementations, the small-diameter section includes a flexible pipe section.

[0005] In some embodiments, the large-diameter section of the cannula is a rigid section, and the flexible section is flexible enough to bend compared to the rigid section.

[0006] In some embodiments, a pull wire outer tube is fixed inside the wall of the cannula, the pull wire extends longitudinally inside the pull wire outer tube, and the proximal end of the pull wire is controlled by an operating unit.

[0007] In some embodiments, the outer diameter of the larger diameter segment is greater than the outer diameter of the smaller diameter segment, and the larger diameter segment is configured to support the curved passage within the ureter so that it deforms from a curved shape to a straight shape.

[0008] In some implementations, the large-diameter section is connected to or integrally formed with the small-diameter section.

[0009] In some embodiments, the large-diameter section is a rigid pipe section, and the small-diameter section includes a flexible pipe section and a transition section, with the transition section connecting the rigid pipe section and the flexible pipe section in the middle.

[0010] In some embodiments, the large-diameter section is a rigid pipe section, the small-diameter section includes a flexible pipe section and a head end, the head end has a higher rigidity than the flexible pipe section, and the distal end of the pull wire is fixed to the head end.

[0011] In some embodiments, the cannula is at least a multi-layered tube in its small diameter section, and the tube wall of the multi-layered tube includes an inner tube, a support layer and an outer tube from the inside to the outside, with the support layer disposed between the inner tube and the outer tube; preferably, the support layer is an elastic layer, preferably a spring tube.

[0012] In some embodiments, a fixing member is provided at the head end, and the pull tube is located inside the wall of the insertion tube.

[0013] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0014] Figure 1 A schematic diagram of the structure of the variable-diameter ureteral guide sheath (with dilator) provided by this utility model;

[0015] Figure 2 A cross-sectional view of the structure of the variable-diameter ureteral guide sheath provided by this utility model;

[0016] Figure 3 A schematic diagram of the structure of the variable-diameter ureteral guide sheath and endoscope combination provided by this utility model;

[0017] Figure 4 for Figure 3 A magnified view of a portion of the image;

[0018] Figure 5 This is a schematic diagram of the structure of the variable-diameter ureteral guide sheath provided by this utility model;

[0019] Figure 6 A schematic diagram of the flexible variable-diameter ureteral guide sheath provided by this utility model;

[0020] Figure 7 for Figure 2 A magnified view of a portion of the image;

[0021] Figure 8 This is a schematic diagram of the urethra.

[0022] Figure 9 The existing design provides a schematic diagram of the ureteral guide sheath entering the renal pelvis;

[0023] Figure 10 A schematic diagram showing the state of the variable-diameter ureteral guide sheath entering the renal pelvis provided by this utility model;

[0024] Figures 11-14 A schematic diagram of the adjustable-bend variable-diameter ureteral guide sheath provided by this utility model. Detailed Implementation

[0025] The present invention or its technical solutions will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings;

[0026] In the description of this invention, "proximal" and "proximal side" refer to the end of the medical device that is closer to the doctor during normal operation, while "distal" and "distal side" usually refer to the end that first enters the patient's body.

[0027] In the description of this invention, it should be noted that, unless otherwise specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0028] Please see Figures 1-4The existing design of the ureteral guide sheath includes an operating part 1 and a cannula 2 suitable for insertion into the ureter. The operating part 1 is connected to the proximal end of the cannula 2. The cannula 2 defines a central channel 100 extending from the proximal end to the distal end. The operating part 1 defines an inlet 12 communicating with the central channel 100 of the cannula 2 for instrument entry. A sealing valve 121 is provided at the inlet 12 for instruments such as an endoscope 3 to pass through in a sealed manner. The operating part 1 has a negative pressure connector 11 communicating with the central channel. During pyelonephrosis, the guide sheath is inserted into the ureter through a dilator 5, and external instruments such as an endoscope 3 pass through the cannula 2. The central channel reaches the target position. The negative pressure connector 11 is connected to the negative pressure suction device. The laser or other instruments enter the cavity through the endoscope 3 to perform lithotripsy or cutting of stones or other tissues in the cavity. The irrigation device injects physiological saline into the cavity through the endoscope channel. The gap between the endoscope 3 and the central channel 100 forms a suction channel. The negative pressure suction device draws the liquid containing the stones out of the body through the suction channel. In this way, the lithotripsy and stone removal work is completed. The distal end of the cannula needs to be able to reach the renal pelvis and bend freely to be aligned with the target (stone fragments or tissues). Therefore, there are strict requirements on its size.

[0029] This embodiment provides a variable-diameter ureteral guiding sheath. The cannula includes a large-diameter segment 22 and a small-diameter segment 21, which are connected. The large-diameter segment 22 is connected to the proximal end of the small-diameter segment 21. The interior of the large-diameter segment 22 defines a large channel 220, and the interior of the small-diameter segment 21 defines a small channel 210. The diameter of the large channel 220 is larger than the diameter of the small channel 210 to accelerate fluid passage. Thus, the small-diameter segment 21 is suitable for entering the target position of the renal pelvis and can move freely, while the large channel defined by the large-diameter segment 22 increases the radial dimension of the suction channel, facilitating the rapid passage of stones or other tissues, accelerating their dislodgement and outflow, and greatly improving efficiency.

[0030] In a further embodiment of this utility model, the distal segment 211 of the small-diameter section is a flexible pipe segment; see below. Figure 6 After the endoscope 3 (flexible endoscope) enters the central channel, its flexible tube segment 211 bends flexibly with the curved part of the flexible endoscope, bending straight to the renal calyx. This design is crucial for lithotripsy and stone removal in the lower calyx and for improving the efficiency of flexible endoscope stone removal.

[0031] Furthermore, the large-diameter section 22 of the cannula is a rigid segment, while the distal section of the small-diameter section 21 is a flexible segment, allowing it to bend. This flexible segment can be actively controlled by the user, the physician. For example, a pull wire can be placed on the wall of the cannula 2 to actively control the bending of the flexible segment relative to the rigid segment. The movement of the pull wire can also be controlled manually or intelligently to control the bending angle or repositioning of the flexible segment. In addition, the proximal side of the cannula uses a rigid component to facilitate the physician's insertion of the guide sheath into the cavity, while protecting the sheath from deformation.

[0032] In some examples, please refer to Figure 5 The large-diameter section is a rigid pipe section, and the small-diameter section includes a flexible pipe section 211 and a transition section 212. The transition section 212 connects the rigid pipe section and the flexible pipe section, and its rigidity is between that of the rigid pipe section and the flexible pipe section. In other examples, the large-diameter section is a rigid pipe section, and the entire small-diameter section is a flexible pipe section.

[0033] Optionally, both the large-diameter section 22 and the small-diameter section 21 can be multi-layer pipes; please refer to [link / reference]. Figure 7 The multi-layer tube, from its inner to outer side, comprises an inner tube 201, a support layer 202, and an outer tube 203. The support layer 202 is disposed between the inner tube 201 and the outer tube 203, thus facilitating the bending of the small-diameter section. For example, the inner tube 201 is often an externally etched PTFE tube, ensuring both effective connection between the inner tube 201 and the outer tube 203 and a smooth inner wall for easy instrument passage. For instance, both the large-diameter section 22 and the small-diameter section 21 are multi-layer tubes, forming an integrated structure. In this way, the support layer 202 increases in size synchronously with the increase in the outer diameter of the large-diameter section 22, resulting in a stable, reliable, and aesthetically pleasing integrated structure. In other examples, the large-diameter section 22 and the small-diameter section 21 are separate structures, with the multi-layered tube ending at the diameter change point. The large-diameter section 22 uses an independent structure, such as a pure plastic tube or a metal tube (stainless steel tube, nickel-titanium tube), and is connected by rheological bonding or adhesive bonding. The small-diameter section 21 is generally made of Pebax material, while the large-diameter section 22 can be made of Pebax material or other materials, or the same material or different materials. The large-diameter section can be distinguished by different colors or transparency, making it easier for doctors to identify the positions of the large-diameter and small-diameter sections without having to retract the endoscope.

[0034] In this embodiment, the outer diameter of the large-diameter segment 22 is larger than that of the small-diameter segment 21, meaning that both the inner and outer diameters of the large-diameter segment 22 are larger. The large-diameter segment 22 is configured to support the curved channel within the ureter, allowing it to straighten from a curved shape. Specifically, the outer diameter and rigidity of the large-diameter segment 22 are designed to support the cavity, thus strengthening the curvature and allowing for straightening deformation. Its length is also longer than the curved cavity to achieve straightening deformation. Compared to existing ureteral sheaths, where stones need to bypass the curved cavity to be expelled, the inherent size limitations of the suction channel make it easy for stones to become stuck at the bend. This invention deforms the curved cavity during surgery and, in conjunction with the enlargement of the suction channel, accelerates stone expulsion efficiency and eliminates the risk of stones easily becoming stuck at the bend. For example, please refer to [link to relevant documentation]. Figure 8 The bladder (a) is bordered by the urethra (b) posterior to it and the ureter (d) anterior to it. The renal pelvis (e) is located anterior to the ureter. The urethra has two curves: the prepubic curve (b1) and the subpubic curve (b2). Please refer to [link / reference]. Figure 9 Existing ureteral guiding sheaths, after entering the ureter, have a gap-like design, making it extremely easy for stones or other tissues to become lodged at the bend, causing suction blockage. Please refer to... Figure 10 The large-diameter section 22 of the variable-diameter ureteral guiding sheath provided in this embodiment is a rigid tube section. It does not deform in the two physiological bends of the male urethra, and directly straightens the two physiological bends. In this way, the flow process of the target object, such as gravel, which originally had to go through two large bend angles to flow out can now be reduced by reducing the flow process of two bend angles, and the occurrence of gravel getting stuck at the bend is eliminated.

[0035] In this embodiment, the cannula 2 is positioned at the junction of the large diameter section 22 and the small diameter section 21 to enter the bladder without contacting the ureteral orifice. Thus, the variable diameter design satisfies the requirement for the small diameter section to enter the bladder while also allowing for the expulsion of stones.

[0036] The cannula 2 has a proximal end and a distal end. In some embodiments of this invention, the tip 2111 of the ureteral guide sheath is adjustable. As mentioned earlier, this adjustment can be achieved by the bending portion of the endoscope causing the tip 2111 to deflect, or by the deflectability of the ureteral sheath itself. In some embodiments, please refer to... Figures 11-12 A pull wire 30 is installed inside the wall of the insertion tube 2. The pull wire 30 is slidably pulled inside the outer tube 31. The far end of the pull wire 30 is fixed to the head end of the small diameter section 21. The operating unit 1 controls and drives the pull wire 30 to move longitudinally relative to the main body section, and then the head end is deflected by the flexible segment.

[0037] In other embodiments, please refer to Figures 13-14Two pull wires 30 are symmetrically arranged inside the cannula wall. Pulling the pull wires 30 causes the flexible segment to deflect upward or downward.

[0038] Understandably, it is also possible to install more than two guy wires.

[0039] Please refer to it again. Figure 13 To achieve the deflection of the pull wire 30, the distal end of the pull wire 30 is fixed to the head end 2111 of the small-diameter section. The head end 2111 is equipped with a fixing member 6 to facilitate the bending and deflection of the flexible segment. It can be understood that the flexible segment, as a bending segment, has a lower stiffness than the nearby pipe segment and the head end. The bending of the flexible segment causes the head end 2111 to deflect. Furthermore, the pull wire tube 31 is disposed between the inner tube 201 and the support layer 202, or it can be disposed in other layers.

[0040] Optionally, the proximal end of the pull cable 30 can be pulled manually or mechanically. In some examples, the operating part 1 is provided with a power transmission component, and the proximal end of the pull cable 30 is located on the power transmission component. The power transmission component is adapted to be connected to a motor, and each pull cable is driven by the power transmission mechanism to slide longitudinally. Exemplarily, the power transmission component is a turntable, and the proximal end of the pull cable 30 is wound on the turntable. The counterclockwise or clockwise rotation of the turntable drives the pull cable to move longitudinally towards the proximal or distal side. The turntable is connected to a corresponding mating part on the equipment, and the power of the motor on the equipment is transmitted to the turntable, and then transmitted to the flexible segment through the pull cable 30.

[0041] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0042] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An adjustable-diameter ureteral guide sheath, comprising an operating part and a cannula adapted for insertion into a ureter, the operating part being connected to the proximal end of the cannula, the cannula defining a central channel extending from the proximal end to the distal end, the operating part defining an inlet communicating with the central channel of the cannula, the inlet being provided with a sealing valve for instruments to pass through and enter the central channel in a sealed manner, the operating part having a negative pressure connector communicating with the central channel, characterized in that... The cannula comprises a large-diameter section and a small-diameter section, the large-diameter section is connected to the proximal end of the small-diameter section, the interior of the large-diameter section defines a large channel, the interior of the small-diameter section defines a small channel, the diameter of the large channel is larger than that of the small channel to accelerate the fluid passing, at least part of the small-diameter section is a flexible tube section; the ureter guide sheath further comprises at least one pull wire, the pull wire extends longitudinally and is arranged in the wall of the cannula, the distal end of the pull wire is fixedly connected to the head end of the small-diameter section, and the longitudinal movement of the pull wire drives the flexible tube section to deflect.

2. The variable diameter ureteral guide sheath of claim 1, wherein, The small-diameter section comprises a flexible tube section.

3. The variable diameter ureteral guide sheath of claim 1, wherein, The large-diameter section of the cannula is a rigid tube section, and the flexible tube section is such that the flexible tube section is bendable compared to the rigid tube section.

4. The variable diameter ureteral guide sheath of claim 1, wherein, A pull wire outer tube is fixedly arranged in the interior of the wall of the cannula, the pull wire longitudinally extends in the pull wire outer tube, and the proximal end of the pull wire is controlled by an operating part.

5. The variable diameter ureteral guide sheath of claim 3, wherein, The outer diameter of the large-diameter section is larger than that of the small-diameter section, and the large-diameter section is configured to support the curved channel in the ureter to deform from a curved shape to a straightened shape.

6. The variable diameter ureteral guide sheath of claim 1 or 2, wherein, The large-diameter section and the small-diameter section are connected or integrally formed.

7. The variable diameter ureteral guide sheath of claim 1, wherein, The large-diameter section is a rigid tube section, the small-diameter section comprises a flexible tube section and a transition section, and the transition section is connected between the rigid tube section and the flexible tube section.

8. The variable diameter ureteral guide sheath of claim 1, wherein, The large-diameter section is a rigid tube section, the small-diameter section comprises a flexible tube section and a head end, the hardness of the head end is greater than that of the flexible tube section, and the distal end of the pull wire is fixed to the head end.

9. The variable diameter ureteral guide sheath of claim 1, wherein, At least the small-diameter section of the cannula is a multilayer tube, the wall of the multilayer tube comprises an inner layer tube, a support layer and an outer layer tube from inside to outside in sequence, and the support layer is arranged between the inner layer tube and the outer layer tube.

10. The variable diameter ureteral guide sheath of claim 9, wherein, The support layer is an elastic layer.

11. The variable diameter ureteral guide sheath of claim 10, wherein, The support layer is a spring tube.

12. The variable diameter ureteral guide sheath of claim 8, wherein, The head end is provided with a fixing member, and the pull wire tube is arranged in the wall of the cannula.

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