Indwelling urethral device

Abstract

The present invention provides a urethral indwelling device that can be stably placed in a predetermined position within the urethra due to its simple structure. [Solution] The urethral indwelling device 1, which is placed inside the urethra, comprises a prostatic loop portion 10 located at the tip and placed in the prostatic urethra, a bulbous urethral loop portion 20 located at the proximal end and placed in the bulbous urethra, and a loop connecting linear portion 30 that connects the prostatic loop portion 10 and the bulbous urethral loop portion 20. The prostatic loop portion 10, the bulbous urethral loop portion 20, and the loop connecting linear portion 30 are composed of a superelastic alloy wire 5 and a flexible covering tube 6 that covers the superelastic alloy wire 5.

Description

Technical Field

[0001] The present invention relates to a urethral indwelling device to be indwelt in the urethra.

Background Art

[0002] When the urethra is closed or narrowed due to prostatic hypertrophy or the like, resulting in urinary disorders, a treatment is performed in which a urethral stent (urethral indwelling device) for widening the urethra is installed in the urethra.

[0003] Such urethral stents are disclosed, for example, in Patent Documents 1 to 3 below. Although the urethral stent needs to be indwelt at a predetermined position such as the prostatic urethra, when the user moves the body, the urethra also deformes accordingly, and in many cases, the urethral stent installed in the urethra is displaced from the predetermined position.

[0004] Therefore, in Patent Documents 1 to 3 below, in order to indwell the urethral stent at a predetermined position, a stopper that engages with a predetermined part in the urethra to prevent further entry, a balloon that expands in the urethra, etc. are installed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, when using a stopper, it is impossible to prevent the urethral stopper from moving forward, and when using a balloon, the structure becomes complicated and the burden on the user is also large.

[0007] This invention has been made in view of these problems, and aims to provide a urethral indwelling device that can be stably placed in a predetermined position within the urethra with a simple structure. [Means for solving the problem]

[0008] The present invention, which solves the above problems, is a urethral indwelling device placed in the urethra, comprising: a prostatic loop portion located at the tip and placed in the prostatic urethra; a bulbous urethral loop portion located at the proximal end and placed in the bulbous urethra; and a loop-connecting linear portion connecting the prostatic loop portion and the bulbous urethral loop portion, wherein the prostatic loop portion, the bulbous urethral loop portion and the loop-connecting linear portion are composed of a superelastic alloy wire and a flexible covering tube covering the superelastic alloy wire. [Effects of the Invention]

[0009] According to the urethral indwelling device of the present invention, the elastic force of the elastically deformed prostatic loop portion and bulbous urethral loop portion expands the urethra, thereby enabling stable placement in a predetermined position while ensuring the passage of urine with a simple urethral indwelling device. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a front view of a urethral indwelling device according to an embodiment of the present invention. [Figure 2] Figure 2 is a plan view of a urethral indwelling device according to an embodiment of the present invention. [Figure 3] Figure 3 is a front view of a urethral indwelling device with the fixing cover removed, according to an embodiment of the present invention. [Figure 4] Figure 4 is a partial cross-sectional view showing the placement of a urethral indwelling device according to an embodiment of the present invention. [Figure 5] Figure 5 is a front view of a modified urethral retainer according to an embodiment of the present invention. [Figure 6]Figure 6 shows the configuration of an intrusion prevention chip according to a modified embodiment of the present invention. [Figure 7] Figure 7 is a partial cross-sectional view showing the placement state of a urethral indwelling device according to a modified embodiment of the present invention. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the urethral indwelling device 1 is characterized by comprising a superelastic alloy wire 5, which is a shape-memory alloy, and a covering tube 6 that covers the wire 5.

[0012] The urethral indwelling device 1 comprises a prostatic loop portion 10, a bulbous urethral loop portion 20, a loop-connecting linear portion 30 that connects the prostatic loop portion 10 and the bulbous urethral loop portion 20, and a retrieval connecting string 50. In this embodiment, the front side that is inserted into the urethra first when the device is placed inside the urethra is referred to as the tip side, and the rear side that is inserted later is referred to as the proximal side.

[0013] The prostatic loop portion 10 is located in the prostatic urethra B when placed in the urethra and functions to widen the prostatic urethra B to ensure the passage of urine. The bulbous urethral loop portion 20 is located in the bulbous urethra C when placed in the urethra and functions to widen the bulbous urethra C to ensure the passage of urine.

[0014] The prostatic loop section 10, the bulbous urethral loop section 20, and the loop-connecting linear section 30 are composed of a single superelastic alloy wire 5 and a translucent resin covering tube 6 that covers the superelastic alloy wire 5. The superelastic alloy wire 5 is inserted into the hollow covering tube 6.

[0015] The super-elastic alloy wire 5 is made of nickel-titanium (Ni-Ti) alloy and is capable of elastic deformation. It exhibits super-elasticity and returns to its original shape at normal room temperature above 0°C or body temperature. The coating tube 6 is a semi-transparent flexible tube made of vinyl. In this embodiment, the outer diameter of the super-elastic alloy wire 5 is 0.3 mm, the outer diameter of the coating tube 6 is 2.5 mm, and the thickness is 0.5 mm.

[0016] Both ends of a single super-elastic alloy wire 5 are folded inward and fixed to a predetermined location of the super-elastic alloy wire 5 respectively. As a result, two loop portions 10 and 20 are formed on the super-elastic alloy wire 5, with the tip side becoming the prostate loop portion 10 and the hand side becoming the bulbous urethra loop portion 20.

[0017] Both ends of the super-elastic alloy wire 5 are fastened and fixed to a predetermined location of the super-elastic alloy wire 5 by extremely thin fastening wires 7 respectively, and then firmly fixed by being covered with a fixing part cover 8 made of epoxy resin. FIG. 3 is a front view of the urethral indwelling device 1 with the fixing part cover 8 removed. Of course, as the material of the fixing part cover 8, other materials such as silicone rubber can be used.

[0018] The super-elastic alloy wire 5 is shape-memorized in an arc shape with a central angle of about 130°, bent from a straight state by about 130°, only in a portion corresponding to the loop connection linear portion 30 near the middle. The portions constituting the other loop portions 10 and 20 of the super-elastic alloy wire 5 are elastically deformed from those shape-memorized in a straight line.

[0019] Therefore, in a state where no external force is applied, as shown in FIG. 1, the longitudinal central axes of the prostate loop portion 10 and the bulbous urethra loop portion 20 are configured to intersect at about 130° with 0° being the parallel state where they are located on a straight line.

[0020] In this embodiment, the plane containing the flattened prostatic loop portion 10 and the plane containing the flattened bulbous urethral loop portion 20 are the same as the plane containing the arc-shaped loop connecting linear portion 30, and regardless of whether the central angle of the arc-shaped loop connecting linear portion 30 is deformed in the opening direction or the closing direction, the prostatic loop portion 10, the bulbous urethral loop portion 20, and the loop connecting linear portion 30 are located on the same plane.

[0021] Furthermore, the loop-connecting linear portion 30, which has a circular arc shape with a central angle of approximately 130°, may be formed by deforming a superelastic alloy wire 5 that has been initially shaped in a straight line into the circular arc shape through plastic deformation, rather than by storing the superelastic alloy wire 5 in a circular arc shape.

[0022] The urethra is generally curved at approximately 90° from the bulbous urethra C to the prostatic urethra B, and the loop-connecting linear portion 30 is curved at approximately 130°. Therefore, when the urethral device 1 is placed inside the urethra, the loop-connecting linear portion 30 will elastically deform in the direction of opening.

[0023] Therefore, when the urethral indwelling device 1 is placed in the urethra, the elastic force of the loop-connecting linear portion 30, which is deformed in the opening direction, generates an elastic force in the closing direction for the urethral indwelling device 1 as a whole, and the prostatic loop portion 10 and the bulbous urethral loop portion 20 are pressed against the inner wall of the urethra. This prevents the urethral indwelling device 1 from moving further in or forward from its placement position in the urethra, enabling stable placement.

[0024] Here, the prostatic loop portion 10 and the bulbous urethral loop portion 20 have an acute angular shape at the fixing cover 8 where both ends of the superelastic alloy wire 5 are fixed, and a curved arc shape at the tip and proximal end of the urethral retainer 1, resulting in an overall elongated, roughly elliptical shape.

[0025] In this embodiment, the length (long axis) of the prostatic loop portion 10 is 3 cm and the width (short axis) is 2 cm, the length of the bulbous urethral loop portion 20 is 5 cm and the width is 2.5 cm, and the length of the loop connecting linear portion 30 is 1.5 cm, but these sizes can be changed as appropriate.

[0026] When the prostatic loop portion 10 is placed in the prostatic urethra B, it is pressed against the inner wall of the prostatic urethra B, elastically deforming so that its width (short axis) becomes narrower to about 1 cm, and is biased to expand by the elastic force pushing back against the inner wall (see Figure 4).

[0027] When the bulbous urethral loop portion 20 is placed in the bulbous urethra C, it is pressed against the inner wall of the bulbous urethra C, elastically deforming so that its width (short axis) becomes narrower to about 1.5 cm, and is further expanded by the elastic force that pushes back against the inner wall.

[0028] The prostatic loop portion 10 and the bulbous urethral loop portion 20 are flattened and located on the same plane. When placed in the urethra, they act to widen the urethra in a predetermined direction, creating a large gap for urine to flow through, allowing users with urinary problems caused by urethral narrowing to urinate smoothly.

[0029] Furthermore, the loop portions 10 and 20 bias the urethral wall back, preventing them from easily moving within the urethra, thus allowing the urethral indwelling device 1 to be stably placed inside the urethra.

[0030] The retrieval connecting string 50 is made of resin thread, with one end connected and fixed to the proximal end of the bulbous urethral loop portion 20 (see Figure 3), and this connected and fixed portion is covered by the fixing portion cover 8. The retrieval connecting string 50 is long enough so that when the urethral device 1 is placed inside the urethra, the other end is exposed outside the urethra (see Figure 4), and when removing the urethral device 1, the bulbous urethral loop portion 20 and the prostatic loop portion 10 can be sequentially removed from inside the urethra by pulling this retrieval connecting string 50.

[0031] The configuration of the urethral indwelling device 1 has been described above. Next, the manner of use of the urethral indwelling device 1 will be described. When inserting the urethral indwelling device 1 into the urethra, the user first pinches the prostatic loop portion 10 to make it thinner, then inserts its tip into the external urethral orifice E, which is the entrance to the urethra, and then gradually pushes the entire prostatic loop portion 10 into the urethra.

[0032] After the entire prostatic loop portion 10 has entered the urethra, the user can push the prostatic loop portion 10 further into the urethra by pinching and pressing the bulbous urethral loop portion 20, which is connected to the prostatic loop portion 10 by the loop connecting linear portion 30.

[0033] Subsequently, when the tip of the bulbous urethral loop portion 20 reaches the entrance of the external urethral orifice E, the bulbous urethral loop portion 20 is further pushed into the urethra. After the entire bulbous urethral loop portion 20 has entered the urethra, the prostatic loop portion 10, the bulbous urethral loop portion 20, and the loop connecting linear portion 30 can be pushed further in by milking or other means.

[0034] Here, the urethra has a relatively long pendulum-like urethra D, and then as it progresses further in through the bulbous urethra C and the prostatic urethra B, it curves approximately 90° upward from horizontal (see Figure 4). Therefore, if the loop-connecting linear portion 30 remains curved at approximately 130°, it would be difficult to smoothly advance the urethral device 1 further in. However, since the prostatic loop portion 10, bulbous urethral loop portion 20, and loop-connecting linear portion 30, which are made of superelastic alloy, elastically deform appropriately to match the shape of the urethra, it is possible to smoothly insert the urethral device 1 further into the urethra.

[0035] When the tip of the prostatic loop portion 10 reaches the external urethral sphincter K after passing through the pendulum urethra D and bulbous urethra C, it is necessary to push it in carefully because the urethra narrows at the external urethral sphincter K. After the tip of the prostatic loop portion 10 has passed the external urethral sphincter K, pushing the prostatic loop portion 10 further will cause the posterior end of the prostatic loop portion 10 to pass the external urethral sphincter K, and the entire prostatic loop portion 10 will be placed in the desired position within the prostatic urethra B (placement state; see Figure 4).

[0036] At this time, the loop-connecting linear portion 30 is located in the external urethral sphincter K, and the bulbous urethral loop portion 20 on the proximal side is positioned and placed inside the bulbous urethra C. In this way, when the flattened prostatic loop portion 10 is placed inside the prostatic urethra B and the flattened bulbous urethral loop portion 20 is placed inside the bulbous urethra C, the prostatic urethra B and the bulbous urethra C can be widened as described above, thereby ensuring the passage of urine.

[0037] Furthermore, in the urethral indwelling device 1, the flattened loop portions 10, 20 and the loop connecting linear portion 30 are located on the same plane. As a result, the direction in which elastic force acts due to the deformation of the loop portions 10, 20 coincides with the direction in which elastic force acts due to the deformation of the loop connecting linear portion 30. This allows for efficient dilation of the urethra, and also makes it relatively easy for the user to insert the urethral indwelling device 1 into the urethra.

[0038] As described above, according to this embodiment, the prostatic loop portion 10 and the bulbous urethral loop portion 20 are connected by a loop-connecting linear portion 30 with an arc shape having a central angle of approximately 130°. Therefore, when inserting the urethral device 1 into the urethra, the loop-connecting linear portion 30 elastically deforms appropriately to match the shape of the urethra, enabling smooth insertion without putting a burden on the urethral mucosa.

[0039] Furthermore, in this embodiment, since a metal loop connecting wire portion 30 with a certain degree of rigidity is used, when inserting the urethral indwelling device 1 into the urethra, even after the prostatic loop portion 10 has entered the urethra, the bulbous urethral loop portion 20 can be grasped and pushed to easily insert the prostatic loop portion 10 connected to the tip further in, making the indwelling procedure easier.

[0040] Furthermore, even after the bulbous urethral loop portion 20 has been inserted into the urethra, the bulbous urethral loop portion 20 is located within the bulbous urethra C, allowing the user to confirm its position from the outside with their finger. This also allows the user to determine the position of the prostatic loop portion 10, which is located further inside and connected to the bulbous urethral loop portion 20 by the loop connecting linear portion 30. In addition, by adjusting the position of the bulbous urethral loop portion 20 located in the pendulum urethra D through methods such as milking, the user can also fine-tune the position of the prostatic loop portion 10.

[0041] Furthermore, in this embodiment, the prostatic loop portion 10, the bulbous urethral loop portion 20, and the loop connecting linear portion 30 are integrally constructed from a single superelastic alloy wire 5 and a single covering tube 6, enabling a simple structure and lightweight design, thereby reducing costs.

[0042] Next, a modified urethral indwelling device 2 according to the present invention will be described with reference to Figures 5 to 7. This modified version is characterized by the addition of a bladder loop portion 60 at the tip and an entry prevention tip 40 on the loop connecting linear portion 30 compared to the urethral indwelling device 1 according to the above embodiment. Therefore, the description will focus on the configuration that differs from the above embodiment.

[0043] The bladder loop portion 60 is located inside the bladder A when the urethral indwelling device 2 is placed in the indwelling position, and when the device attempts to come out towards the proximal end, the bladder loop portion 60 catches on the entrance to the bladder A (internal urethral sphincter J), thereby preventing it from coming out.

[0044] The bladder loop portion 60 is connected and fixed to the tip side of the prostate loop portion 10 by the second loop connecting linear portion 31. The bladder loop portion 60 and the second loop connecting linear portion 31 are composed of a single superelastic alloy wire 5 separate from the prostate loop portion 10, etc., and a covering tube 6 that covers it. The bladder loop portion 60 is formed by folding one end of this single superelastic alloy wire 5 inward and connecting and fixing it in a predetermined place.

[0045] The other end of this single superelastic alloy wire 5 is connected and fixed to the tip of the prostate loop portion 10, and the connection portion is securely connected and fixed by a retaining wire 7 (not shown) and a fixing portion cover 8, similar to the embodiment described above.

[0046] In this modified example, the central angle of the arc-shaped loop connecting linear portion 30 is 60°. The second loop connecting linear portion 31 is stored in a linear shape.

[0047] The intrusion prevention chip 40 is a flat plate made of epoxy resin with a roughly oval shape (track shape) (see Figure 6). Figure 6(a) is a perspective view of the intrusion prevention chip 40 as seen from one surface side, and Figure 6(b) is a perspective view as seen from the other surface side.

[0048] A wire insertion hole 41 is formed in the center of the intrusion prevention chip 40 through which the loop connecting linear portion 30 passes, and multiple communication holes 45 are formed around the wire insertion hole 41. When the intrusion prevention chip 40 is installed in the urethra, urine can pass through these communication holes 45 during urination.

[0049] As shown in Figure 6, the wire insertion hole 41 is shaped so that the inclination angle of the loop connecting linear portion 30 relative to the surface of the anti-entry tip 40 can be freely changed from a vertical position to a 20° inclined position. Figure 5 shows the anti-entry tip 40 in a state where it is parallel to the loop connecting linear portion 30 and inclined to 20°, and Figure 7 shows the anti-entry tip 40 in a state where it is perpendicular to the loop connecting linear portion 30. By positioning the anti-entry tip 40 in this horizontal position, it can be smoothly inserted deep into the urethra.

[0050] In this embodiment, the diameter of the wire insertion hole 41 is 2 mm, which is smaller than the outer diameter of the covering tube 6, which is 2.5 mm. However, since the outer diameter of the superelastic alloy wire 5 is 0.3 mm and the thickness of the covering tube 6 is 0.5 mm, and the sum of the outer diameter of the superelastic alloy wire 5 and twice the thickness of the covering tube 6 (1.3 mm) is smaller than the diameter of the wire insertion hole 41, the loop connecting linear portion 30 can pass through the wire insertion hole 41 while the flexible resin covering tube 6 deforms.

[0051] At this time, the intrusion prevention tip 40 is fixed to a predetermined location on the loop connecting linear portion 30 by the frictional force of the deformed covering tube 6. However, by applying a force to the intrusion prevention tip 40 that exceeds this frictional force, it is also possible to slide the intrusion prevention tip 40 to any position relative to the loop connecting linear portion 30. By adjusting the position of the intrusion prevention tip 40 by sliding, the placement position of the prostatic loop portion 10 can be adjusted.

[0052] When the urethral device 2 is placed in the urethra, as the entry prevention tip 40, which enters the urethra following the prostatic loop portion 10, approaches the narrow external urethral sphincter K from the relatively wide bulbous urethra C, the edge of the entry prevention tip 40 that collides with the external urethral sphincter K cannot advance further, and as the portion of the wire insertion hole 41 connected to the loop connecting linear portion 30 approaches the external urethral sphincter K, the entry prevention tip 40 gradually changes its posture to a state where it is standing perpendicular to the loop connecting linear portion 30.

[0053] When the wire insertion hole 41 of the intrusion prevention tip 40 reaches the external urethral sphincter K, the intrusion prevention tip 40 becomes vertical and collides with the external urethral sphincter K, preventing it from advancing any further into the urethra. At this time, if the installation position of the intrusion prevention tip 40 is adjusted so that the prostatic loop portion 10 is positioned just within the prostatic urethra B, it is possible to reliably prevent the prostatic loop portion 10 from going too far beyond the prostatic urethra B.

[0054] Even if the intrusion prevention tip 40 is in a vertical position and in contact with the entrance of the external urethral sphincter K, the intrusion prevention tip 40 has multiple communication holes 45 formed in it, and urine can pass through these communication holes 45 and be discharged.

[0055] Furthermore, when the flat-shaped anti-entry tip 40 is in a vertical position, the urethra is widened by the outer diameter of the anti-entry tip 40. However, since the bulbous urethral portion C in front of the external urethral sphincter K is a relatively wide urethral section, this does not pose an excessive physical burden to the user.

[0056] This modification provides the same effects as the above embodiment, and by installing the bladder loop portion 60 at the tip, it is possible to more reliably prevent the urethral indwelling device 2, which is placed in a predetermined position, from coming out towards the proximal end.

[0057] Furthermore, by installing the intrusion prevention chip 40, the prostatic loop portion 10 can be precisely positioned in the desired location, and the urethral insertion device 2, once positioned in the predetermined location, can be prevented from going too far in.

[0058] Although embodiments of the present invention, including variations, have been described above, the embodiments of the present invention are not limited to those described above, and various modifications are possible without departing from the spirit of the invention. For example, the material, shape, size, etc., of the components constituting the urethral indwelling device can be changed as appropriate.

[0059] Furthermore, the central angle of the loop-connecting linear portion, which is arc-shaped, can be changed as appropriate. Generally, considering that the entire urethra, from the bulbous urethra to the prostatic urethra, is curved by approximately 90°, it is desirable that the central angle of the loop-connecting linear portion be approximately 50 to 140°.

[0060] Furthermore, in the above embodiment, the prostatic loop portion, the bulbous urethral loop portion, and the loop connecting linear portion are located on the same plane, but the configuration of the urethral device is not limited to this, and the positional relationship of each component can be changed as appropriate. The plane containing the prostatic loop portion and the plane containing the loop connecting linear portion may be perpendicular to each other. [Explanation of Symbols]

[0061] 1,2 Urethral indwelling device 10 Prostatic loop 20. Bulbous urethral loop 30 Loop connecting linear section 31 Second loop connecting linear section 40 Intrusion prevention chips 41 Wire insertion hole 45 Communication hole 50 Retrieval connection string 60 Bladder loop 5. Superelastic alloy wire 6. Covering tube 7. Retaining wire 8. Fixing part cover A Bladder B. Prostatic urethra C bulbar urethra D Pendulum urethra E. External urethral orifice J internal urethral sphincter K External urethral sphincter

Claims

1. In a urethral indwelling device that is placed inside the urethra, The prostatic loop portion is located at the tip and is placed in the prostatic urethra, A bulbous urethral loop portion is located on the proximal side and is placed in the bulbous urethra, A loop-connecting linear portion that connects the prostatic loop portion and the bulbous urethral loop portion, A urethral indwelling device comprising the prostatic loop portion, the bulbous urethral loop portion, and the loop connecting linear portion, characterized in that they are composed of a superelastic alloy wire and a flexible covering tube that covers the superelastic alloy wire.

2. The urethral indwelling device according to claim 1, characterized in that the loop connecting linear portion is arc-shaped with a central angle of 50 to 140°.

3. The urethral indwelling device according to claim 2, characterized in that the prostatic loop portion and the bulbous urethral loop portion are flattened and located on a plane including the arc-shaped loop connecting linear portion.

4. The urethral indwelling device according to claim 1, characterized in that the superelastic alloy wire constituting the prostatic loop portion, the bulbous urethral loop portion, and the loop connecting linear portion is connected in a single unit.

5. A bladder loop portion located at the tip of the aforementioned prostatic loop portion and placed inside the bladder, The urethral indwelling device according to claim 1, further comprising a second loop connecting linear portion that connects the prostatic loop portion and the bladder loop portion.

6. Further comprising an entry prevention chip, which is connected to the loop connecting linear portion between the prostatic loop portion and the bulbous urethral loop portion, and is sized to collide with the internal urethral sphincter within the urethra and prevent it from advancing further, The urethral retaining device according to claim 1, characterized in that the entry prevention tip has an insertion hole formed therein with a diameter smaller than the outer diameter of the covering tube through which the loop connecting linear portion passes, is slidable relative to the loop connecting linear portion, and can be fixed in a predetermined position by frictional force with the covering tube.

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