Prostate stent system and delivery device thereof

Abstract

The utility model provides a prostate stent system and a delivery device thereof, the delivery device is used for placing the prostate stent into the prostate, the delivery device comprises a pushing tube, a pre-collection tube and a sheathing canal, the pushing tube and the pre-collection tube are movably arranged in the sheathing canal in a penetrating mode in the longitudinal direction, the pre-collection tube is coaxially arranged on the far side of the pushing tube, and the pre-collection tube is coaxially arranged on the far side of the pushing tube. The pushing tube is suitable for a traction rope to penetrate through, the pre-collecting tube is suitable for containing the near end of the stent body, and the prostate stent is contained in the sheathing canal under the pulling force of the pushing tube.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to a prostate stent and its delivery device for treating benign prostatic hyperplasia or urethral stricture. Background Technology

[0002] The prostate is a gland in the male reproductive system, connected to the bladder and urethra, with the sphincter muscles below. A normal prostate is about 20 ml in size, roughly the size of a walnut. However, various factors can lead to benign prostatic hyperplasia (BPH), which puts pressure on the urethra, causing difficulty urinating and damaging bladder function. This can result in symptoms such as difficulty urinating, urinary frequency, urinary incontinence, interrupted urination, or weak urine flow. As the condition worsens, urethral stones, bladder strain, urinary tract infections, and even kidney damage may occur. Current treatments often involve medication or surgery. Medication is often not very effective, while surgery is prone to complications, potentially leading to loss of sexual function. To address these issues, prostate stents were developed. Made of shape-memory alloy, the stent is assembled externally and delivered to the affected area. The patient's body temperature causes it to expand and regain its shape, thus stretching the affected tissue and achieving a therapeutic effect. The expansion of the stent against the urethral tissue over several days causes urethral tissue degeneration. This tissue degeneration occurs due to ischemic compression of various lines on the tissue cells, leading to reduced or complete lack of blood flow. As a result, the lack of blood flow causes oxygen deprivation in the cells and ultimately cell death. Within a few days, the tissue can shrink to the point where urine flow almost returns to normal. After the treatment is completed, the implant can be retrieved from the urethra via a catheter.

[0003] The prior art provides a method for placing a prostate stent in the prostatic urethra of a patient, with the following specific steps: An elastic prostate stent is encased in a sheath, and the stent, in a compressed state, is pre-loaded into the sheath. The sheath containing the stent is inserted through the urethra and pushed distally along the urethra until the distal end of the sheath reaches and extends into the patient's bladder. The stent within the sheath is pushed distally, causing it to gradually dislodge from the distal end of the sheath. Once the stent is freed from the sheath's constraint, its elastic properties cause it to return to its initial expanded state. The proximal end of the stent has a stent base, which transmits rotational torque through a matching tool; the operator can use this structure to rotate and adjust the stent within the bladder to the target orientation. The stent is pulled back proximally, ultimately positioning it in the prostatic urethra and / or bladder neck region. The stent is maintained in this position for a predetermined time (e.g., several hours to several days), during which continuous contact with the urethral wall tissue creates a longitudinal incision in the circumferential urethra, thereby relieving urethral stricture. After the indwelling period, the sheath is reinserted and the implant is wrapped, forcing the implant to compress back to its initial contracted size from its expanded state. Subsequently, the compressed implant is withdrawn from the urethra entirely through the sheath. This method utilizes the elastic deformation recovery properties of the prostate stent to achieve non-invasive delivery and tissue cutting; time-dependent cutting replaces traditional surgical incisions, reducing operative trauma. Traditional stents lack effective anchoring structures at the proximal end, making them prone to displacement due to bladder neck contraction or external forces; stents adhere to tissues after placement, requiring a second surgery for removal and easily causing mucosal damage; and the stent cannot be repositioned after release, resulting in low surgical success rates. Utility Model Content

[0004] This utility model provides a delivery device for a prostate stent. The delivery device is used to insert a prostate stent into the prostate. The delivery device includes a push tube, a pre-retract tube, and a sheath. The push tube and the pre-retract tube are movably inserted into the sheath in the longitudinal direction. The pre-retract tube is coaxially disposed on the distal side of the push tube. The push tube is adapted to allow a traction rope to be inserted therein. The pre-retract tube is adapted to accommodate the proximal end of the stent body therein. The prostate stent is accommodated in the sheath under the pulling force of the push tube.

[0005] In some embodiments, the small diameter of the push tube is smaller than the inner diameter of the pre-retracted tube and smaller than the contracted outer diameter of the proximal end of the support body.

[0006] In some embodiments, the push tube has an operating handle section extending to the outer side of the proximal end of the sheath.

[0007] This utility model also provides a prostate stent system, which includes a prostate stent and the aforementioned delivery device.

[0008] The advantages of this invention are that it abandons the traditional stent base design, simplifies the insertion process, and improves patient comfort; and reduces stress concentration through a multi-point anchoring structure, thereby optimizing stent stability and safety.

[0009] This invention also provides a matching delivery system, including a sheath, a push tube, and a pre-retract tube, which enables precise release and removal of the stent. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the prostate stent provided in Example 1 in its released state;

[0011] Figure 2 A top view of the prostate stent provided in Example 1 in its deployed state;

[0012] Figure 3 This is a schematic diagram of another prostate stent provided in Example 1;

[0013] Figure 4 This is a schematic diagram of another prostate stent provided in Example 1;

[0014] Figure 5 This is a schematic diagram of the prostate stent system provided in Example 2 during the retraction process;

[0015] Figure 6 for Figure 5 A magnified view of a portion of the image.

[0016] 1-Support body, 11, 12, 13-Support ridges, 21, 22, 23-Distal connection, 31, 32, 33-Proximal connection, 51, 52, 53-Pull rope, 6-Traction rope, 310, 320, 330-Proximal end of proximal connection, 100-First connection segment, 101-Anchoring part, 102-Second connection segment, 7-Biofilm, 8-Through hole, 91-Sheath tube, 92-Push tube, 93-Pre-retraction tube. Detailed Implementation

[0017] Please see Figure 1 and Figure 2This utility model provides a prostate stent, which includes a stent body 1 and pull cords 51, 52, and 53. The stent body 1 is made of shape memory alloy and includes three longitudinally extending support ribs 11, 12, and 13. The distal ends of every two adjacent support ribs 11, 12, and 13 are joined by distal connecting parts 21, 22, and 23, and the proximal ends of every two adjacent support ribs 11, 12, and 13 are joined by proximal connecting parts 31, 32, and 33. The number of pull cords 51, 52, and 53 is the same as the number of proximal connecting parts 31, 32, and 33. The distal end of each pull cord 51, 52, and 53 is independently connected to a proximal connecting part 31, 32, and 33. The proximal ends of all pull cords 51, 52, and 53 converge at the distal end of the same traction cord 6. The proximal end of the traction cord is pulled by the operator. The stent body 1 is bundled together by the pull cords 51, 52, and 53. Please refer to [link to relevant documentation]. Figure 1 , Figure 5 and Figure 6 The proximal ends 310, 320, and 330 of the proximal connecting portion switch between an expanded state and a contracted state by means of the traction rope 6. In the description of this utility model, "proximal end" and "proximal side" refer to the end of the medical device that is closer to the doctor during normal operation, while "distal end" and "distal side" usually refer to the end that first enters the patient's body.

[0018] The prostate stent provided by this invention does not converge at the stent base as in existing technologies. During insertion, the stent base does not need to be placed inside the prostate, avoiding pressure on the urethra from foreign objects other than the shape-memory metal stent. This simplifies the stent insertion process and improves patient comfort. Furthermore, this invention uses the linkage control of the traction rope 6 and the pull ropes 51, 52, and 53 to dynamically switch between expansion and contraction states at the proximal ends 310, 320, and 330 of the stent body 1, rather than being fixed in a single non-expansion state. In addition, during prostate stent expansion, the proximal ends 310, 320, and 330 of the three proximal connecting parts 31, 32, and 33 are evenly attached to the inner wall of the urethra. Multi-point anchoring disperses stress, avoiding stress concentration caused by traditional single-point anchoring (such as a locking tongue structure). Finally, by eliminating the rigid constraint of the traditional stent base, the prostate stent of this invention has superior self-expansion stability, further improving safety and long-term efficacy.

[0019] In one embodiment of this invention, the proximal connecting portions 31, 32, and 33 include radially outwardly folded anchoring wings. These anchoring wings, in conjunction with the supporting ridges 11, 12, and 13, and the distal connecting portions 21, 22, and 23, are positioned at the proximal, main, and distal ends of the prostate, respectively, forming a multi-level stable spatial anchoring structure. Especially under the pressure of prostatic hyperplasia, the folding design of the anchoring wings effectively prevents the stent from sliding or falling off, ensuring that the stent remains in the predetermined position. Specifically, the anchoring wings are folded radially outward relative to the two supporting ridges they engage.

[0020] In some embodiments, the radial folding angle of the anchoring wing is 30°-90° to ensure that the anchoring wing forms sufficient contact with the inner wall of the urethra in the expanded state, while avoiding poor anchoring effect due to excessively large or small angles.

[0021] In some examples, the anchoring wing includes a first connecting section 100, a U / V-shaped anchoring portion 101, and a second connecting section 102. The first connecting section 100 and the second connecting section 102 are respectively connected to the proximal ends of two adjacent support ribs 11, 12, and 13, and transition is achieved through the anchoring portion 101. Pull ropes 51, 52, and 53 are fixedly connected to the middle section of the anchoring portion 101. The U / V-shaped design enhances the anchoring strength while reducing frictional irritation to the urethral mucosa.

[0022] In this embodiment, the distal connecting portions 21, 22, and 23 include distal support ribs, which are divided into a third connecting segment, a middle segment, and a fourth connecting segment along their length. The third connecting segment and the fourth connecting segment are respectively connected to the distal ends of two adjacent support ribs 11, 12, and 13. The cross-sectional area of ​​the distal base defined by the distal connecting portions 21, 22, and 23 is smaller than that of the main support frame defined by the main support ribs 11, 12, and 13, so that the distal base can be positioned with minimal contact area when it enters the bladder, avoiding excessive expansion or pressure on the bladder wall, thereby reducing the risk of bladder spasm.

[0023] To further illustrate the structure of the stent body 1 of this utility model, the structure of the stent body 1 is further described as follows: The stent body 1 includes three closed loops. Each closed loop line extending from the proximal end to the distal end includes proximal connecting portions 31, 32, and 33, two side edges, and distal connecting portions 21, 22, and 23. Each side edge of each closed loop line connects to the other side edge of another closed loop line to form a support ridge 11, 12, and 13. That is, the stent body 1 provided by this utility model collectively constitutes a closed polygon, thereby improving the stent's support performance for tissues.

[0024] In some embodiments of this invention, the stent body 1 is coated with a drug-eluting coating. Preferably, please refer to... Figure 3The main support frame defined by the main support edges 11, 12, and 13 is provided with a biofilm 7, and the biofilm 7 is coated with a drug coating. Optionally, the biofilm 7 is a 0.01mm-3mm thick biomaterial or chemical material film, and a drug coating may be applied to the biofilm 7. The coated drug may be paclitaxel or rapamycin. Please refer to [link to relevant documentation]. Figure 4 The biofilm 7 can be provided with through holes 8 to increase the air permeability of the membrane material. This solution can be used to cover any one or multiple sides. After covering, it is optional to drill holes, and the drilling method is not limited.

[0025] Optionally, the support body 1 is made of a shape memory metal wire, and its two free ends are joined by a connector.

[0026] Based on the aforementioned prostate stent, this invention provides a novel delivery device. Please refer to [link to relevant documentation]. Figure 5 and Figure 6 The delivery device includes a sheath 91, a push tube 92, and a retractable tube 93. The push tube 92 has an internal channel for the traction rope 6 to pass through. The retractable tube 93 is coaxially located at the distal end of the push tube 92 and is used to temporarily accommodate the proximal ends 310, 320, and 330 of the stent body 1. Its shape can be annular, circular, or polygonal, and it is connected to the push tube 92 by adhesive bonding, interference fit, or threaded connection. The sheath 91 is used to accommodate the unreleased portion of the stent body 1. The stent body 1 is accommodated in the sheath 91 under the tension of the push tube 92. Thus, the proximal end of the stent body 1 is retracted into the retractable tube 93 under the tension of the traction rope 6. After the stent body 1 is released from the sheath 91, the angle of the stent is adjusted by rotating the push tube 92. After confirming the position, the traction rope 6 is released to allow the proximal ends 310, 320, and 330 to expand and anchor. This design reduces the outer diameter of the delivery device by 20%-30% compared to traditional structures, significantly reducing invasive injuries.

[0027] Based on the prostate stent system provided by this utility model, the stent body 1 includes a proximal end and a main body portion, wherein the proximal end is adapted to be received in a pre-retracting tube 93, and the pre-retracting tube 93 and the main body portion are adapted to be received in a sheath 91, providing the following method for prostate stent insertion and removal:

[0028] Insert a stent:

[0029] The size of the patient's prostate C is measured using ultrasound and other examination equipment, and the stent size is selected according to its size. The stent is then inserted into the delivery device, and the stent body 1 retracts in the sheath 91 and the pre-retraction tube 93. The delivery device is inserted into the patient's urethral opening, and the delivery position of the delivery device is observed with the help of ultrasound and other detection equipment. When the delivery device passes through the prostate C and reaches the patient's bladder opening A, the push tube 92 is moved distally to slowly release the prostate stent until the main body of the stent body 1 has fully expanded. Then, the traction rope 6 is tightened, and the position of the push tube 92 is adjusted to adjust the position of the stent body 1 in the target tissue. After the position adjustment is completed, the proximal end of the prostate stent body 1 is released from the pre-retraction tube 93 through the relative movement of the traction rope 6 and the push tube 92 (e.g., loosening the pre-tightened traction rope 6). The delivery device is then removed.

[0030] Remove the bracket:

[0031] Pulling the traction rope 6 causes the proximal end of the support body 1 to retract into the pre-retracting tube 93. Pulling the push tube 92 then collects the remaining part of the support body 1 into the sheath tube 91.

[0032] In this embodiment, the outer diameter of the push tube 92 ranges from 1mm to 5mm, the inner diameter ranges from 0.5mm to 4.5mm, and the length ranges from 500mm to 1000mm; the outer diameter of the sheath tube 91 ranges from 2mm to 6mm, the inner diameter ranges from 1mm to 5mm, and the length ranges from 500mm to 1000mm; the shape of the pre-retracting tube 93 includes, but is not limited to, annular, round, polygonal, and stepped tubes, and the connection method with the push tube 92 includes, but is not limited to, adhesive bonding, interference fit connection, threaded connection, and heat fusion connection, etc. At the same time, the inner hole of the pre-retracting tube 93 can smoothly pass through the traction rope, and the pre-retracting tube moves flexibly in the sheath tube; the diameter of the traction rope (line) ranges from 0.1mm to 2mm, and the length ranges from 500mm to 2000mm.

[0033] Example 2

[0034] This embodiment is basically the same as the structure of Embodiment 1, except that the prostate stent provided by this utility model includes four longitudinally extending support ridges, and correspondingly also includes four pull ropes.

[0035] 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 present 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.

[0036] Although embodiments of the present 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 present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A delivery device for a prostate stent, characterized in that, The delivery device is used to insert a prostate stent into the prostate. The delivery device includes a push tube, a retractor tube, and a sheath. The push tube and the retractor tube are movably inserted into the sheath in the longitudinal direction. The retractor tube is coaxially located on the distal side of the push tube. The push tube is adapted to allow a traction rope to be inserted therein. The retractor tube is adapted to receive the proximal end of the stent body therein. The prostate stent is received in the sheath under the pulling force of the push tube.

2. The delivery device according to claim 1, characterized in that, The small diameter of the push tube is smaller than the inner diameter of the pre-retracted tube and smaller than the contracted outer diameter of the proximal end of the support body.

3. The delivery device according to claim 1, characterized in that, The push tube has an operating handle section extending to the outside of the proximal end of the sheath.

4. A prostate stent system, characterized in that, The system includes a prostate stent and the delivery device as described in claim 1, 2 or 3.

Images