Stent device

Abstract

To treat prostate enlargement and a constriction of the prostatic urethra while also maintaining the bladder neck and internal urethral sphincter unobstructed.SOLUTION: A stent device comprises: two closed elliptical pressure wires, each having a prostatic urethra section and a bladder neck section for exerting an outward radial pressure on the prostatic urethra and the bladder neck; and a plurality of bridging elements for coupling the two closed elliptical pressure wires together along a length of the pressure wires. A width of the prostatic urethra section is larger than a width of the bladder neck section of each of the pressure wires. Each of the two closed elliptical pressure wires and the plurality of bridging elements are elastic and have shape memory thereby giving the stent device an expanded configuration and also being compressible into a compressed configuration. In the expanded configuration, the pressure wires exert the outward radial pressure on the prostatic urethra and the bladder neck.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The technology of this disclosure relates generally to stent devices for enlarging the prostatic urethra and unobstructing the internal urethral sphincter and bladder neck to reduce prostatic hyperplasia (eg, as a result of benign prostatic hyperplasia). [Background technology]

[0002] The prostate is a walnut-sized gland that forms part of the male reproductive system. It is located in front of the rectum and just below the bladder, where urine is stored. The urethra is the tube that connects the bladder to the penis, through which urine can leave the body. It can be subdivided into four distinct anatomical sections known as the preprostatic urethra, prostatic urethra, membranous urethra, and corpus cavernosum. The preprostatic urethra passes through the bladder neck, the distal section of the bladder adjacent to the prostate. In the male reproductive system, the ejaculatory ducts are tubes that connect the testes to the urethra, through which semen can also leave the body. The prostate surrounds a portion of the urethra called the prostatic urethra, which also passes through the prostate and connects with the prostatic urethra. A short section of the urethra distal to the prostatic urethra is the membranous urethra, located at the urethral bulb. The corpus cavernosum is the portion of the urethra that runs along the length of the penis and ends at the urethral opening. Two sphincters control the release of urine from the bladder. The internal urethral sphincter, located at the bladder neck at the intersection between the preprostatic urethra and the prostatic urethra, is an involuntary muscle that controls the flow of urine from the bladder into the urethra. The internal urethral sphincter also prevents the flow of semen into the bladder when a man ejaculates and semen enters the prostatic urethra through the ejaculatory ducts. The external urethral sphincter, located at the distal base of the prostate gland at the intersection between the prostatic urethra and the membranous urethra, is a voluntary muscle that controls the flow of urine from the prostate gland to the urethral opening.

[0003] The prostate itself is anatomically composed of four lobes: the anterior, middle, posterior, and lateral lobes. The anterior, middle, and posterior lobes surround the urethra, and the ejaculatory ducts pass through the middle and posterior lobes. The lateral lobes are positioned around the anterior, middle, and posterior lobes. The anatomical landmark on the prostatic urethra used to classify specific urethral developmental disorders is known as the verumontanum or seminal colliculus. The verumontanum is located between the ejaculatory ducts, prostatic lice, and prostatic ducts and is inferior to the urethral crest.

[0004] Reference is now made to Figures 1A and 1B, which are schematic diagrams of the male reproductive system, prostate, and urethra, generally referenced 10 and 40, respectively, as known in the prior art. Referring to Figure 1A, a schematic diagram of the male reproductive system from a sagittal view is shown. As can be seen, the bladder 12 connects with the urethra 16, which drains into the penis 28. Below the bladder 12, the prostate gland 14 surrounds the urethra 16. The distal portion of the bladder 12 is designated as the bladder neck 15, which is adjacent to the prostate gland 14. The portion of the urethra 16 that passes through the bladder neck 15 is designated as the preprostatic urethra 13. The portion of the urethra 16 that is surrounded by the prostate gland 14 is designated as the prostatic urethra 24. Multiple ejaculatory ducts 18 join the urethra 16 at the prostatic urethra 24. Within the section of the prostatic urethra 24, the urethral ridge 26, the prostatic ventricles 20, and the verumontanum 22 are shown. The distal end of the prostatic urethra 24 opens into a section of the urethra 16 known as the membranous urethra 21, which is then surrounded by the penis 28 and continues into the corpus cavernosum 23, which terminates at the urethral meatus (not shown). As can also be seen, an internal urethral sphincter 25 is located at the intersection between the preprostatic urethra 13 and the prostatic urethra 24, and an external urethral sphincter 27 is located at the intersection between the prostatic urethra 24 and the membranous urethra 21.

[0005] Referring to FIG. 1B, a schematic view of the prostate gland is shown in a sagittal view 42A and a transverse view 42B. Identical elements in the sagittal view 42A and the transverse view 42B are designated using the same reference numerals. As can be seen in the sagittal view 42A, the anterior lobe 44, the posterior lobe 46, and the middle lobe 48 surround the urethra 52. The ejaculatory duct 54 passes through the posterior lobe 46 and the middle lobe 48. Similarly, the verumontanum 56 at the proximal end of the posterior lobe 46 is also shown. As can be seen in the transverse view 42B, multiple lateral lobes 50 surround the anterior lobe 44, the posterior lobe 46, and the middle lobe 48, and the urethra 52 runs between the various lobes of the prostate gland.

[0006] Common medical conditions of the prostate include inflammation, noncancerous prostatic hyperplasia, and prostate cancer. Noncancerous prostatic hyperplasia, also known as benign prostatic hyperplasia, is a medical condition that primarily occurs in older men (generally over 50) in which the prostate gland increases in size but is not due to metastasis or uncontrolled cell proliferation. As the prostate gland enlarges and increases in size, as can be seen from its anatomical location in a human male as shown in Figure 1A, it can exert pressure on adjacent anatomical sites, such as the urethra, particularly the prostatic urethra, as well as the bladder neck (the lower part of the bladder that connects to the urethra) and the ejaculatory duct. Generally, when the prostate gland enlarges, it is the lateral lobe that enlarges and exerts pressure on the prostatic urethra. However, in some cases, the middle lobe can also enlarge. Prostatic hyperplasia can lead to many medical problems, such as benign prostatic hyperplasia (BPH) and prostatic bladder neck obstruction (BNO). BPH causes increased pressure in the prostatic urethra, making urination difficult and painful. BNO can cause complete obstruction of the prostatic urethra and an inability of the muscles around the bladder neck (e.g., the internal urethral sphincter) to relax and contract, making urination nearly impossible and usually requiring medical intervention to remove urine from the bladder.

[0007] Treatments for medical problems resulting from prostatic hyperplasia range from orally taken medications (to reduce the size of the prostate by reducing hormone production), various types of stents and implants to enlarge the prostatic urethra, the use of catheters to allow urine to drain from the bladder to the penis, and surgical procedures to remove either a portion of the prostate (such as transurethral resection of the prostate) or the entire prostate (such as prostatectomy). Stents and implants for opening the prostatic urethra are known in the art. International Publication No. 2006 / 040767, entitled "Prostate Treatment Stent" to Kilemnik, is directed to a tissue-dissecting implant. The implant is spring-shaped and includes multiple rings elastically connected between them. Adjacent rings apply pressure to the tissue trapped between the rings, thereby pinching the trapped tissue and inducing necrosis.

[0008] U.S. Patent No. 8,715,239 to Lamson et al., entitled "Devices, Systems, and Methods for Treating Benign Prostatic Hyperplasia and Other Conditions," is directed to a system including a rigid introducer device that can be used to facilitate insertion of an implant into the prostate. The implant includes a proximal anchor connected to a distal anchor by a tensioning element, and the introducer device includes a rigid, elongated body that can be inserted into the subject's urethra. The introducer device also includes a rigid endoscope lumen and a rigid working lumen configured to receive a cystoscope or other endoscopic device. The working lumen is used to position a prostatic compression implant and has an exit port that allows the implant to be advanced through the wall of the urethra to a location within or near the prostate.

[0009] U.S. Patent No. 10,478,283 to Bachar, entitled "Dilating Device for Prostatic Urethra," is directed to a device for dilating the prostatic urethra comprising at least three laterally connected ridges, each ridge configured to longitudinally engage a different substantially longitudinal groove in a patient's prostatic urethra. The laterally connected ridges are configured to be laterally compressed to allow insertion into the prostatic urethra in a compressed configuration, and the connected ridges are also configured to laterally expand to a normally open configuration upon deployment within the prostatic urethra. When deployed, the connected ridges exert a radially outward force that dilates the prostatic urethra.

[0010] Prior art techniques offer solutions to the pressure exerted on the prostatic urethra when the lateral lobes of the prostate enlarge, a more common form of BPH. However, enlargement of both the lateral and middle lobes of the prostate can lead to additional complications. As described below, the enlarged middle lobe can exhibit sufficient movement within the prostatic urethra to block the bladder neck after urination, thereby causing BNO. During regular urination in men, when the muscles around the bladder contract and compress the bladder, the muscles around the bladder neck (such as the internal urethral sphincter) relax, allowing urine into the prostatic urethra. As urine leaves the bladder, air pressure is generated within the bladder, which pushes urine from the bladder into the urethra. After urination ends, when the muscles around the bladder relax and the muscles around the bladder neck contract to close the bladder neck, negative air pressure and suction can be generated in the prostatic urethra. In cases of BPH in which only the lateral lobes of the prostate enlarge, negative air pressure may not affect the opening of the bladder neck. However, in cases of BPH in which the lateral and middle lobes are enlarged, negative air pressure (i.e., suction) can pull the enlarged middle lobe toward the bladder neck, thereby also causing BNO. While prior art solutions can provide relief to patients experiencing BPH by dilating and opening the prostatic urethra, complications from BPH can further result in BNO, in which the internal urethral sphincter becomes blocked. In such cases, simply dilating and opening the prostatic urethra is insufficient to provide relief.

[0011] Prior art treatment methods for such cases (either BNO, BPH with BNO, or BPH and BNO with an enlarged middle lobe) typically use some form of laparoscopic surgery, such as transurethral resection of the prostate or laser surgery, to remove a portion of the prostate, such as the middle lobe, to relieve symptoms. Therefore, what is needed is a minimally invasive treatment, such as an implant or stent device, that can open the prostatic urethra and treat the symptoms of BPH, while simultaneously keeping both the internal urethral sphincter and bladder neck unobstructed, thereby also treating the symptoms of BNO. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] International Publication No. 2006 / 040767 [Patent Document 2] U.S. Patent No. 8,715,239 [Patent Document 3] U.S. Patent No. 10,478,283 Summary of the Invention [Problem to be solved by the invention]

[0013] It is an object of the disclosed technology to provide a stent device, such as a prostatic urethral implant, for treating prostatic hyperplasia and strictures of the prostatic urethra while keeping the bladder neck and internal urethral sphincter unobstructed. [Means for solving the problem]

[0014] The technology of the present disclosure overcomes the drawbacks of the prior art by providing a stent device, such as a prostatic urethral implant, positioned within the prostatic urethra, the shape of which is extended to include the prostatic urethra and the bladder neck. The stent device includes at least one pressure wire that applies a radial force to the surrounding tissue of the inner wall of the prostatic urethra and the inner wall of the bladder neck. The pressure wire has a generally closed elliptical shape, similar to the shape of a wing. The pressure wire is made of a biocompatible metal that is elastic and has shape memory so that it can be compressed for insertion into the urethra and then expanded once positioned within the prostatic urethra and the bladder neck. When expanded, the pressure wire applies a radial force along the length of the prostatic urethra and the bladder neck, thus enlarging the prostatic urethra and providing relief from BPH, while also keeping the internal urethral sphincter and bladder neck unobstructed, thereby providing relief from BNO. The at least one pressure wire maintains outward radial pressure on the prostatic urethra and the internal urethral sphincter, thereby relieving stricture of the prostatic urethra while keeping the bladder neck open. Thus, the stent device provides a solution to a strictured prostatic urethra due to BPH, as well as a solution for preventing BNO by keeping the internal urethral sphincter unobstructed.

[0015] The stent device of the disclosed technology can be permanently positioned within a patient's urethra, or it can be temporarily positioned within the urethra and later removed (i.e., the stent device can be a retractable device). A cannula or sheath (e.g., as part of a cystoscope) inserted into the urethra through the urethral opening can be used to position the stent device within the prostatic urethra. Surgical forceps can then be inserted into the cannula to precisely position the stent device and hold it in place while the cannula is removed, allowing the stent device to open to its expanded form. Surgical forceps can also be used to rotate the pressure wire of the stent device to the desired position and move the bladder neck portion of the pressure wire into the patient's bladder neck. According to the disclosed technology, the reverse procedure can also be used to collapse the stent device and remove it from the patient by using forceps to compress the stent device and retract it into the cannula for removal from the patient. In accordance with the techniques of the present disclosure, the stent device may be removed when outward radial pressure on the prostatic urethra is no longer needed, for example, if the prostatic lobes decrease in size over time. Similarly, the stent device may be permanently maintained within the prostatic urethra to provide relief from BPH.

[0016] The stent device of the presently disclosed technology can be embodied with a single pressure wire or multiple pressure wires. In one embodiment, the stent device has two pressure wires, both wing-shaped, connected to each other via multiple bridging elements. In a second embodiment, the stent device has two pressure wires, also wing-shaped, but directly connected to each other without multiple bridging elements. In a third embodiment, the stent device has a single pressure wire shaped like a vase. In each of these embodiments, the stent device of the presently disclosed technology includes a prostatic urethra section and a bladder section. Generally, the shape of the pressure wire can also resemble a leaf or teardrop with a distal curve for applying pressure radially outward. It should be noted that the addition of a bladder section to the stent device of the presently disclosed technology is one of the features that distinguishes the stent device from the prior art.

[0017] The stent device may also include at least one additional wire to secure and hold in place enlarged lobes of the prostate, such as an enlarged middle lobe, which may contribute to BNO. This additional wire may be referred to as a fixation wire. The fixation wire can be used as an anchor to hold the stent device in place and prevent migration of the stent device into the bladder, while also applying pressure to the middle lobe of the prostate, thus preventing movement of the middle lobe after urination (due to suction). As explained above, in some cases of BPH, not only do the lateral lobes of the prostate enlarge in BPH, but the middle lobe may also enlarge. In such cases, the proximal side of the middle lobe closest to the prostatic urethra may form a drooping, bulbous end. Due to the suction generated during urination, when a man stops urinating, suction from the bladder may pull the bulbous end toward the bladder neck, thereby causing BNO. Thus, even when the prostatic urethra is free from the overall constriction caused by the enlargement of the lateral lobes of the prostate, the bulbous, pendulous end of the middle lobe has sufficient movement to occlude the bladder neck. The at least one fixation wire of the disclosed technology has a closed configuration and acts as an anchor to limit the movement of the bulbous, pendulous end of the enlarged middle lobe. Similarly, the fixation wire is an additional mechanism for preventing the stent device from migrating toward the bladder.

[0018] In another embodiment of the disclosed technology, a stent device can have two fixation wires, each shaped like a leaf, a young leaf, or a teardrop. The first fixation wire serves as an additional means for securing the pressure wire of the stent device to prevent the stent device from migrating into the bladder over time. The second fixation wire secures the spherical, drooping end of the middle lobe to prevent it from moving when suction occurs after urination. Both the first and second fixation wires have outwardly curving curves, thereby applying outward radial pressure. The two fixation wires are joined at the proximal end of the stent device and have different lengths corresponding to the anatomy of the prostatic urethra to which they are attached. The first fixation wire is long enough to apply pressure to the verumontanum when the stent device is positioned within the prostatic urethra, thereby preventing the stent device from migrating toward the bladder. The first fixation wire can be used as an additional means for holding the stent device in place without the need to permanently affix the stent device to tissue within the prostatic urethra (e.g., without the need to use adhesives, sutures, or other means for connecting the implant to tissue within the body). The second fixation wire is long enough so that, when the stent is positioned within the prostatic urethra, the second fixation wire applies pressure to the spherical, pendulous end of the middle lobe, thereby preventing the spherical, pendulous end of the middle lobe from being sucked toward the bladder and obstructing the bladder neck after urination. Given the anatomical structure of the prostate and prostatic urethra and the fact that the stent device is inserted into the urethra via the penis, the second fixation wire is longer than the first fixation wire because the spherical end of the middle lobe is distal to the penis relative to the verumontanum.

[0019] In cases of BPH involving hypertrophy of the middle lobe and in which the stent device of the disclosed technology includes at least one fixed wire, the stent device has a fixed wire or extension to prevent the bulbous end of the middle lobe from moving, meaning that the stent device of the disclosed technology remains permanently or semi-permanently implanted within the prostatic urethra. This is because the stent device of the disclosed technology does not reduce the size of the enlarged middle lobe and / or change its composition, and therefore must be permanently maintained in place to prevent the bulbous end of the middle lobe from causing BNO. Once the size of the middle lobe is reduced (e.g., by medication, surgery, or other techniques) and the bulbous end of the middle lobe is no longer a concern for causing BNO, the stent device of the disclosed technology can be removed from the prostatic urethra. In this regard, the stent device of the disclosed technology can be semi-permanent.

[0020] In this description, the terms pressure and force (e.g., applying radial pressure or applying radial force) are used interchangeably hereinafter to describe the action of the wires of the stent device on the surrounding tissue and anatomical landmarks within the prostatic urethra and bladder neck. That is, the wires (pressure and fixation) are described as applying pressure to the tissue or as applying an outward radial force to the tissue. Hereinafter, the terms proximal and distal refer to directions relative to the stent device. In particular, the distal end is the end of the stent device that is inserted first into the patient's body and reaches the deepest (i.e., into the bladder neck). The proximal end is the end closer to the exit from the patient's body and is located in the prostatic urethra near the external urethral sphincter. Therefore, with respect to the technology of the present disclosure, the bladder is the most distal point, while the urethral opening of the penis is the most proximal point.

[0021] The technology of the present disclosure is generally described using an embodiment having two push wires, allowing those skilled in the art to easily understand how the description can be modified to apply the technology of the present disclosure to the other embodiments described above. This applies to embodiments having a single push wire, as well as embodiments further including one fixed wire and two fixed wires. While the technology of the present disclosure is described with reference to the human male reproductive system, the technology of the present disclosure (i.e., stent device) is equally applicable to the reproductive systems of male animals having prostates or glands anatomically and homologously similar to the human male prostate. Additionally, the technology of the present disclosure is described as a stent or stent device due to its similarity to the general function of a stent, which is to keep a passageway, in this case the prostatic urethra and bladder neck, open and unconstricted. However, the technology of the present disclosure may also be referred to as an implant, such as a prostatic urethral implant, and may be described as such herein. Accordingly, the terms "stent," "stent device," and "implant" are interchangeable in this regard.

[0022] The techniques of the present disclosure will be more fully understood and appreciated from the following detailed description taken in conjunction with the drawings, in which: [Brief explanation of the drawings]

[0023] [Figure 1A] 1 is a schematic diagram of the male reproductive system and prostate gland as known in the prior art. [Figure 1B] 1 is a schematic diagram of the male reproductive system and prostate gland as known in the prior art. [Figure 2A] 1 is a schematic diagram of a different embodiment of a first stent device in an expanded configuration for expanding the inner wall of the prostatic urethra while keeping the bladder neck and internal urethral sphincter unobstructed, constructed and operable in accordance with an embodiment of the disclosed technology. [Figure 2B]1 is a schematic diagram of a different embodiment of a first stent device in an expanded configuration for expanding the inner wall of the prostatic urethra while keeping the bladder neck and internal urethral sphincter unobstructed, constructed and operable in accordance with an embodiment of the disclosed technology. [Figure 2C] 1 is a schematic diagram of a different embodiment of a first stent device in an expanded configuration for expanding the inner wall of the prostatic urethra while keeping the bladder neck and internal urethral sphincter unobstructed, constructed and operable in accordance with an embodiment of the disclosed technology. [Figure 2D] 2B is a schematic illustration of the stent device of FIG. 2A in a contracted configuration for insertion into the prostatic urethra, constructed and operative in accordance with another embodiment of the disclosed technique; [Figure 3A] FIG. 10 is a schematic diagram of another embodiment of a second stent device in an expanded configuration for expanding the medial wall of the prostatic urethra and compressing the middle lobe while keeping the bladder neck and internal urethral sphincter unobstructed, constructed and operative in accordance with further embodiments of the disclosed technology. [Figure 3B] FIG. 10 is a schematic diagram of another embodiment of a second stent device in an expanded configuration for expanding the medial wall of the prostatic urethra and compressing the middle lobe while keeping the bladder neck and internal urethral sphincter unobstructed, constructed and operative in accordance with further embodiments of the disclosed technology. [Figure 4] 10 is a schematic illustration showing the placement of a stent device within the prostatic urethra and bladder neck, constructed and operative in accordance with yet another embodiment of the disclosed technique; DETAILED DESCRIPTION OF THE INVENTION

[0024] Reference is now made to Figures 2A, 2B, and 2C, which are schematic illustrations of different embodiments of a first stent device, generally referenced 100, 130, and 150, respectively, in an expanded configuration for expanding the inner wall of the prostatic urethra while keeping the bladder neck and internal urethral sphincter unobstructed, constructed and operative in accordance with embodiments of the disclosed technology. With particular reference to Figure 2A, a first embodiment of the first stent device 100 is shown in an expanded configuration. As shown, the stent device 100 has two closed sections 102A and 102B, both of which are wing-like in shape and have a generally elliptical configuration. The closed section 102A is a substantial mirror image of the closed section 102B. Each of the closed sections 102A and 102B has an outward radial curvature when in the expanded configuration. The closed sections 102A and 102B are connected to one another via a plurality of bridging elements 104. Although three bridging elements 104 are shown in FIG. 2A , any number of bridging elements is possible and is a design choice for the stent device 100, from a single bridging element to many bridging elements. The closed-shaped sections 102A and 102B and the plurality of bridging elements 104 are each made from a resilient biocompatible metal that also has shape memory, such as nickel titanium (also known as nitinol), so that the closed-shaped sections 102A and 102B can be folded into a compressed configuration for insertion into the urethra for device deployment. Each of the plurality of bridging elements 104 has a generally curved shape in the form of an arch. All portions of the stent device 100 should be made from biocompatible materials to avoid the risk of infection from the stent device 100 to the patient's body, which generally applies to all embodiments of the disclosed technology.

[0025] Stent device 100 is designed to be inserted into the urethra in the direction of arrow 103, with the proximal end of stent device 100 designated by reference numeral 105A and the distal end of stent device 100 designated by reference numeral 105B. Also shown is the division of each of closed sections 102A and 102B into a prostatic urethra section 106 and a bladder neck section 108. Although each of closed sections 102A and 102B is in a closed configuration, the width of each closed section varies along the length of stent device 100 in the direction of arrow 103. As shown, in prostatic urethra section 106, closed section 102A has a width designated by arrow 110A, while in bladder neck section 108, closed section 102A has a width designated by arrow 110B. As can be seen, arrow 110B is significantly shorter than arrow 110A.

[0026] Stent device 100 is designed to be positioned within a patient's prostatic urethra (not shown) so that each of closed-configuration sections 102A and 102B applies outward radial pressure to the prostatic urethra to dilate and widen it and apply outward pressure to enlarged lobes that may narrow the prostatic urethra and cause BPH. The width of prostatic urethra section 106, indicated by arrow 110A, is sufficient to apply sufficient pressure to the medial wall of the prostatic urethra to relieve stricture caused by enlarged lobes of the prostate. The distal portions of closed-configuration sections 102A and 102B also apply outward pressure to the bladder neck to prevent it from obstructing. The width of bladder neck section 108, indicated by arrow 110B, is sufficient to apply sufficient pressure to the medial wall of the anterior prostatic urethra to prevent bladder neck obstruction. Stent device 100 is positioned within the urethra such that prostatic urethra section 106 is positioned within the patient's prostatic urethra and bladder neck section 108 is positioned within the patient's bladder neck, and thus substantially within the patient's preprostatic urethra. As shown, closed configuration sections 102A and 102B have sufficient length in the direction of arrow 103 such that proximal end 105A of stent device 100 is positioned at the proximal end of the prostatic urethra near the external urethral sphincter (not shown), while distal end 105B of stent device 100 is positioned within the bladder neck near the internal urethral sphincter (not shown). Note that the difference in width between prostatic urethra section 106 and bladder neck section 108 (representing the difference in length between arrows 110A and 110B) ensures that stent device 100 does not migrate into the bladder over time. As mentioned above, after urination, negative pressure can build up within the bladder, which can pull anatomical elements within the prostatic urethra toward the bladder (discussed below). The negative pressure could also, in theory, pull a stent device placed within the prostatic urethra toward the bladder, thus causing further medical complications due to migration of the stent device from its intended location within the urethra.In accordance with the techniques of the present disclosure, the bladder neck section of the stent device has a width significantly smaller than the prostatic urethral section to prevent the stent device from migrating toward the bladder and simultaneously allow outward radial pressure to be applied to the bladder neck while substantially remaining in its implanted and positioned state without the need for the use of additional and / or external elements to keep the stent device properly positioned.

[0027] As discussed above, stent device 100 can be implanted permanently, semi-permanently, and temporarily within a patient, depending on the patient's condition. Unlike prior art devices that may only provide relief from BPH by dilating the prostatic urethra, the disclosed technology as embodied in stent device 100 can provide relief from BPH and BNO due to the increased length of each of closed sections 102A and 102B.

[0028] With particular reference to FIG. 2B, a second embodiment of the first stent device 130 is shown in an expanded configuration. Similar to stent device 100 (FIG. 2A), stent device 130 includes two closed sections 132A and 132B, both of which are wing-like and have a generally elliptical configuration. Closed section 132A is a substantial mirror image of closed section 132B. Each of closed sections 132A and 132B has an outward radial curvature when in the expanded configuration. Also similar to stent device 100, stent device 130 includes a prostatic urethra section 136 and a bladder neck section 138, with prostatic urethra section 136 positioned within the patient's prostatic urethra and bladder neck section 138 positioned within the patient's bladder neck. As shown, stent device 130 does not include any bridging elements. Thus, closed section 132A is directly connected to closed section 132B as indicated by arrow 134. The connection of the two closed sections as indicated by arrow 134 can be by adhesive, welded joints, pins, hinges, etc.

[0029] Generally, stent device 130 is substantially similar to stent device 100 (FIG. 2A) in terms of structure and flexible materials, and similarly functions to keep the prostatic urethra unobstructed while keeping the bladder neck unobstructed. Also, like stent device 100, the width difference (not shown) between prostatic urethra section 136 and bladder neck section 138 ensures that stent device 130 does not migrate within the patient's bladder neck and bladder, but rather remains positioned between the external urinary sphincter (at the proximal end of the prostatic urethra) and the internal urinary sphincter (at the distal end of the bladder neck) without any external elements (e.g., supports, sutures, etc.).

[0030] With particular reference to FIG. 2C , a third embodiment of a first stent device 150 is shown in an expanded configuration. Unlike stent devices 100 ( FIG. 2A ) and 130 ( FIG. 2B ), stent device 150 includes only a single, closed-shaped section 152 that is substantially vase-shaped. It will be seen that the vase-like shape of stent device 150 resembles the two-wing shape of stent devices 100 and 130 and includes both a prostatic urethra section 154 and a bladder neck section 156. As shown, a maximum width 153A of prostatic urethra section 154 is significantly greater than a maximum width 153B of bladder neck section 156. When properly positioned within a patient, prostatic urethra section 154 is positioned within the patient's prostatic urethra, and bladder neck section 156 is positioned within the patient's bladder neck.

[0031] The closed section 152 has an outward radial curvature when in the expanded configuration and is made of a biocompatible, flexible metal with shape memory. Stent device 150 does not include any bridging elements and consists of a single closed section, making it cost-effective to manufacture. Similar to stent devices 100 (FIG. 2A) and 130 (FIG. 2B), stent device 150 functions similarly to keep the bladder neck open while also keeping the prostatic urethra open and free of stricture. Also similar to stent devices 100 and 130, the difference in widths 153A and 153B between prostatic urethra section 154 and bladder neck section 156 ensures that stent device 150 does not migrate within the patient's bladder neck and bladder, but rather remains positioned between the external urinary sphincter (at the proximal end of the prostatic urethra) and the internal urinary sphincter (at the distal end of the bladder neck) without any external elements (e.g., supports, sutures, etc.).

[0032] 2D, which is a schematic illustration of the stent device of FIG. 2A in a contracted configuration for insertion into the prostatic urethra, generally referenced 170, constructed and operative in accordance with another embodiment of the disclosed technique. As shown, stent device 170 is substantially similar to stent device 100 (FIG. 2A) and includes two closed sections 172A and 172B and a plurality of bridging elements 174. In FIG. 2D, closed sections 172A and 172B fold over one another, with the plurality of bridging elements 174 folded in half. Due to the outward radial pressure that closed sections 172A and 172B can exert when in their expanded configuration, closed sections 172A and 172B, in their contracted configuration as shown in FIG. 2D, must be retained within a sheath, cannula, and / or delivery tube to remain in their contracted configuration. Once the sheath, cannula, and / or delivery tube are inserted into the urethra to deploy the stent device, the sheath, cannula, and / or delivery tube are removed while holding the stent device in place. Once the sheath, cannula, and / or delivery tube are removed, closed sections 172A and 172B open to their expanded configurations as shown in FIG. 2A (and as shown below in FIG. 4). Stent devices 130 (FIG. 2B) and 150 (FIG. 2C) have similar shapes when collapsed to their contracted forms.

[0033] 3A and 3B, which are schematic illustrations of different embodiments of a second stent device, generally referenced 200 and 230, respectively, in an expanded configuration for expanding the inner wall of the prostatic urethra while keeping the bladder neck and internal urethral sphincter unobstructed and compressing the medial lobe, constructed and operative in accordance with further embodiments of the disclosed technology. With particular reference to FIG. 3A, the illustrated stent device 200 is substantially similar to stent device 150 (FIG. 2C) and includes a single, closed-shaped section 202, has a vase-like shape, and includes a prostatic urethral section 204 and a bladder neck section 206. As shown, the maximum width of the prostatic urethral section 204 is indicated by arrow 208, and the maximum width of the bladder neck section 206 is indicated by arrow 210.

[0034] Stent device 200 differs from stent device 150 ( FIG. 2C ) in that stent device 200 also includes a fixed wire 212 coupled to closed section 202 at its proximal end, shown as base section 205. Fixed wire 212 has a similar vase-like shape to closed section 202, with its greatest width indicated by arrow 214 at the prostatic urethra section 204 and its greatest width indicated by arrow 216 at the bladder neck section 206. Fixed wire 212, like closed section 202, is made from a biocompatible, flexible metal with shape memory. Generally, both closed section 202 and fixed wire 212 apply outward radial pressure, and fixed wire 212 has an outward radial curvature. Closed section 202 is used to keep the prostatic urethra free of stricture while keeping the bladder neck free of obstruction. The fixation wire 212 is used to apply pressure to the patient's middle lobe (not shown) by compressing it. The fixation wire 212 thus prevents the enlarged middle lobe from moving around and migrating toward the bladder neck, which may occur if the enlarged middle lobe has a bulbous end that may be pulled toward the bladder neck after urination due to negative pressure. Generally, it is the distal end of the fixation wire 212 that applies pressure to the bulbous end of the enlarged middle lobe, thus ensuring that the enlarged middle lobe does not move and / or migrate toward the bladder when positioned within the urethra.

[0035] The base section 205 may include a cap (not shown) that can be used to rotate the stent device 200 when positioned within the urethra. The cap has a hollow space that allows urine to pass through when the cap is positioned within the urethra. The hollow space can also be used by a physician or surgeon to rotate the stent device 200 and properly orient the anchor wire 212 so that it compresses the middle lobe. Generally, the hollow space is not circular in shape, thus allowing the cap to be rotated using an instrument (not shown) having a shape complementary to the hollow space. The non-circular hollow space of the cap is configured to receive a corresponding non-circular pin (i.e., an instrument) and transmit the rotational movement of the pin to the stent device 200.

[0036] 3B, the stent device 230 shown is substantially similar to stent device 200 (FIG. 3A) in that it includes a single closed section 232, has a vase-like shape, and includes a prostatic urethra section 238 and a bladder neck section 240. Stent device 230 differs from stent device 200 in that stent device 230 includes a first anchor wire 234 and a second anchor wire 236, both of which are joined to closed section 232 at their proximal ends, shown as base section 235. First anchor wire 234 and second anchor wire 236 each have a leaf-like shape and, like closed section 232, are made from a biocompatible, flexible metal with shape memory. Generally, the closed-shape section 232, the first fixation wire 234, and the second fixation wire 236 apply outward radial pressure, and the first fixation wire 234 and the second fixation wire 236 have outward radial curves. The closed-shape section 232 is used to keep the prostatic urethra free of stricture while maintaining the bladder neck free of obstruction. The first fixation wire 234 can be used as an additional anchor to apply pressure to the verumontanum of the prostatic urethra, thus further ensuring that the stent device 230 does not move while positioned inside the urethra. Generally, the distal end of the first fixation wire 234 is positioned distal to the verumontanum. The second fixation wire 236 is similar to the fixation wire 212 (FIG. 3A), and its distal end is used to apply pressure to the patient's middle lobe (not shown) by compressing it. Thus, the second fixation wire 236 prevents the enlarged middle lobe from moving around and migrating toward the bladder neck, which can occur if the enlarged middle lobe has a bulbous end that can be pulled toward the bladder neck after urination due to negative pressure (i.e., suction).

[0037] Similar to stent device 200 (FIG. 3A), base section 235 may include a cap (not shown) that can be used to rotate stent device 230 when positioned within the urethra. The cap has a hollow space that allows urine to pass through when the cap is positioned within the urethra. The hollow space, having a non-circular shape as described above in FIG. 3A, can also be used by a surgeon to rotate stent device 230 and properly orient first anchor wire 234 so that it compresses the verumontanum of the prostatic urethra, and second anchor wire 236 so that it compresses the middle lobe. Similar to the first stent device described above in FIGS. 2A-2C, stent devices 200 and 230 can be implanted permanently, semi-permanently, or temporarily, depending on the patient's condition.

[0038] Generally, after any of the stent devices of the disclosed technology is implanted, the patient can resume their normal lifestyle without any hindrance. For example, the pressure applied by the first and second fixation wires 234 and 236 is sufficient to maintain the position of the stent device 230 within the prostatic urethra and compress the median lobe without causing any pain and / or discomfort to the patient. In addition, the shape of the first and second fixation wires 234 and 236 is unobtrusive (because the shape of the fixation wires is substantially hollow), thereby allowing fluids and liquids (e.g., urine, prostatic secretions, semen, etc.) to pass unimpeded past the first and second fixation wires 234 and 236. Generally, the lengths of the first and second fixation wires 234 and 236 (as well as fixation wire 212 ( FIG. 3A )) may need to be altered accordingly to perform their respective functions of compression and fixation. The pressure applied by the closed section 232 on the prostatic urethra and bladder neck is sufficient to open the prostatic urethra and bladder neck, readily allowing urine to pass without discomfort. Similarly, it should be noted that any of the stent devices of the disclosed technology described herein can be implanted in any tubular organ requiring relief of a stricture while simultaneously restricting mobility of the anatomical structure, such as tubular organs of the digestive system, blood vessels, etc.

[0039] As shown in Figure 3A, the second stent device 200 can provide relief for urethral strictures, can hold the bladder neck open, and can apply pressure to the bulbous end of the middle lobe to prevent BNO. As shown in Figure 3B, the second stent device 230 can provide relief for urethral strictures, can hold the bladder neck open, can apply pressure to the bulbous end of the middle lobe to prevent BNO, and can also compress the verumontanum to provide an additional anchor to maintain the position of the stent device 230 when placed in the urethra.

[0040] It should be noted that the closed-geometry sections of stent devices 100, 130, 150, 200, and 230 (FIGS. 2A-2C and 3A-3B) can be fabricated from flexible, biocompatible metal wires with cross-sections as thin as 0.5 millimeters. The thickness of such metal wires must be strong enough to apply force to the tissue surrounding the prostate to relieve strictures of the prostatic urethra and maintain the bladder neck open. Similarly, the anchor wires in stent devices 200 and 230 must be strong enough to apply sufficient radial force to compress the middle lobe and verumontanum to prevent fluids and liquids from passing through the urethra and dislodging the anchor wires. Thus, the anchor wires can have cross-sections as thin as 0.5 millimeters.

[0041] Reference is now made to FIG. 4, which is a schematic illustration showing the placement of a stent device, generally referenced 260, within the prostatic urethra and bladder neck, constructed and operative in accordance with yet another embodiment of the disclosed technology. FIG. 4 illustrates a sagittal cross-section of the prostatic urethra and bladder neck with a stent device 270 (e.g., substantially similar to stent device 100 of FIG. 2A ) of the disclosed technology positioned therein. Urethra 262 is shown, along with prostatic urethra 263, bladder neck 265, and bladder 266. Stent device 270 is shown as having a prostatic urethra section 264 and a bladder neck section 268. Stent device 270 includes two closed sections 2721 and 2722 connected to one another via multiple bridging elements 276. The distal ends of closed sections 2721 and 2722 are shown as distal ends 2741 and 2742 within bladder neck section 268.

[0042] When implanted, as shown, the proximal end of stent device 270 seats at the proximal end of the prostatic urethra near the external urethral sphincter, while the distal end of stent device 270 seats at the distal end of the bladder neck near the internal urethral sphincter. The portions of closed sections 2721 and 2722 within the prostatic urethra apply an outward radial force along the tissue of the medial wall of the prostatic urethra, thereby opening the prostatic urethra 263 and relieving stricture in cases of BPH. Distal ends 2741 and 2742 maintain the bladder neck 265 open, thus keeping the bladder neck unobstructed in cases of BNO. As described above, stent device 270 may be permanently, semi-permanently, or temporarily positioned within the prostatic urethra and bladder neck.

[0043] It will be appreciated by persons skilled in the art that the technology of the present disclosure is not limited to what has been particularly shown and described above. Rather, the scope of the technology of the present disclosure is defined only by the following claims. [Explanation of symbols]

[0044] 12 Bladder 13 Preprostatic urethra 14 Prostate 15 Bladder neck 16 Urethra 18 Ejaculatory duct 20 Prostate ventricle 21 Membranous urethra 22 Verumontanum 23 Cavernous urethra 24 Prostatic urethra 25 Internal urethral sphincter 26 Urethral crest 27 External urethral sphincter 28 Penis 42A Sagittal view 42B cross section 44 Anterior lobe 46 Posterior lobe 48 Nakaha 50 Lateral lobe 52 Urethra 54 Ejaculatory duct 56 Verumontanum 100 Stent Device 102A Closed Section 102B Closed Section 103 Arrow 104 Crosslinking element 105A proximal end 105B Distal end 106 Prostatic Urethral Section 108 Bladder Neck Section 110A Arrow 110B Arrow 130 Stent Device 132A Closed Section 132B Closed Section 134 Arrow 136 Prostatic Urethral Section 138 Bladder Neck Section 150 Stent Devices 152 Section 153A Maximum width of prostatic urethra section 153B Maximum width of bladder neck section 154 Prostatic Urethral Section 156 Bladder Neck Section 170 Stent Device 172A Closed Section 172B Closed Section 174 Crosslinking element 200 Stent Devices 202 Closed Shape Sections 204 Prostatic Urethral Section 205 Base Section 206 Bladder Neck Section 208 Arrow 210 Arrow 212 Fixed Wire 214 Arrow 216 Arrow 230 Stent Device 232 Closed Shape Sections 234 Fixed Wire 235 Base Section 236 Second fixed wire 238 Prostatic Urethral Section 240 Bladder Neck Section 262 Urethra 263 Prostatic urethra 264 Prostatic Urethral Section 265 Bladder neck 266 Bladder 268 Bladder Neck Section 270 Stent Device 276 Crosslinking element 2721 Closed Shape Section 2741 distal end

Claims

1. 1. A stent device for enlarging the prostatic urethra and unobstructing the bladder neck of a patient, comprising: two closed-shape pressure wires, each having a prostatic urethra section and a bladder neck section for exerting outward radial pressure on the prostatic urethra and the bladder neck; a plurality of bridging elements for connecting the two closed-shaped pressure wires to one another along the length of the pressure wires; Equipped with each of the closed shaped pressure wires has a closed oval shape; a width of the prostatic urethra section greater than a width of the bladder neck section of each of the pressure wires; each of the two closed pressure wires and the plurality of bridging elements is elastic and has shape memory, thereby providing the stent device with an expanded configuration and being compressible to a compressed configuration; A stent device, wherein in the expanded configuration, the pressure wire exerts the outward radial pressure on the prostatic urethra and the bladder neck.

2. the two closed-shaped pressure wires and the plurality of bridging elements; Nickel titanium (nitinol), and Biocompatible metals, The stent device of claim 1 made from a material selected from the list consisting of:

3. The stent device of claim 1 , wherein the closed oval shape resembles a wing shape.

4. 1. A stent device for enlarging the prostatic urethra and unobstructing the bladder neck of a patient, comprising: two closed-configuration pressure wires, each having a prostatic urethra section and a bladder neck section for exerting outward radial pressure on the prostatic urethra and the bladder neck; each of the closed shaped pressure wires has a closed oval shape; the two closed-shaped pressure wires are joined together by a bond along the length of the pressure wires; a width of the prostatic urethra section greater than a width of the bladder neck section of each of the pressure wires; each of the two closed pressure wires is elastic and has a shape memory, thereby providing the stent device with an expanded configuration and also compressible to a compressed configuration; A stent device, wherein in the expanded configuration, the pressure wire exerts the outward radial pressure on the prostatic urethra and the bladder neck.

5. The two closed-shaped pressure wires are Nickel titanium (nitinol), and Biocompatible metals, The stent device of claim 4 made from a material selected from the list consisting of:

6. The stent device of claim 4 , wherein the closed oval shape resembles an wing shape.

7. The bond is Adhesion, Welding joints, pins, and hinge, The stent device of claim 4, wherein the stent device is selected from the list consisting of:

8. 1. A stent device for enlarging the prostatic urethra and unobstructing the bladder neck of a patient, comprising: a closed-configuration pressure wire having a prostatic urethra section and a bladder neck section for exerting outward radial pressure on the prostatic urethra and the bladder neck; the closed pressure wire has a closed oval shape; a width of the prostatic urethra section greater than a width of the bladder neck section of the pressure wire; the pressure wire is elastic and has shape memory, thereby providing the stent device with an expanded configuration and being compressible to a compressed configuration; A stent device, wherein in the expanded configuration, the pressure wire exerts the outward radial pressure on the prostatic urethra and the bladder neck.

9. The closed-shaped pressure wire is Nickel titanium (nitinol), and Biocompatible metals, 9. The stent device of claim 8, made from a material selected from the list consisting of:

10. The stent device of claim 8 , wherein the closed oval shape resembles the shape of a vase.

11. The stent device of claim 8 , further comprising a fixed wire coupled to a proximal end of the pressure wire and having a closed configuration.

12. The stent device of claim 11 , wherein the fixed wire has a width that is less than the width of the prostatic urethra section.

13. The stent device of claim 11 , wherein the fixed wire is for compressing the middle lobe.

14. The stent device of claim 8 , further comprising two fixed wires each coupled to a proximal end of the pressure wire and having a closed configuration.

15. The stent device of claim 14, wherein the two fixed wires each have a width less than the width of the prostatic urethra section.

16. 15. The stent device of claim 14, wherein a first of the two fixation wires is for compressing the middle lobe and a second of the two fixation wires is for anchoring the stent device within the prostatic urethra.

17. 15. The stent device of claim 14, wherein a first of the two fixed wires is longer than a second of the two fixed wires, and the two fixed wires are shorter in length than the closed configuration pressure wire.

18. The stent device of claim 11, further comprising a cap coupled to the proximal end of the pressure wire for coupling the fixed wire to the pressure wire, the cap comprising a hollow space.

19. The stent device of claim 14, further comprising a cap coupled to the proximal end of the pressure wire for coupling the two fixed wires to the pressure wire, the cap comprising a hollow space.

20. The stent device of claim 18 , wherein the hollow space of the cap comprises a non-circular shape.

21. the hollow space is configured to receive a corresponding mechanism; The stent device of claim 20, wherein the non-circular shape is configured to transfer rotational motion of the corresponding mechanism to the stent device.

22. The corresponding mechanism is pins, and tool, 22. The stent device of claim 21, selected from the list consisting of:

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