Abstract:
A urethral stent device comprising a mechanical valve system is provided. The urethral stent device can be delivered up through the urethra via a flexible delivery tool. The valve mechanism is adapted to open when exposed to a certain amount of intraluminal pressure and can remain open until a desired cessation of fluid flow is achieved.

Description:
PRIORITY 
     This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61/445,699, filed Feb. 23, 2011 and entitled “Incontinence Stent System,” which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to surgical methods and apparatus and, more specifically, to urethral stent systems and methods. 
     BACKGROUND OF THE INVENTION 
     Pelvic health for men and women is a medical area of increasing importance, at least in part due to an aging population. Examples of common pelvic ailments include incontinence (e.g., fecal and urinary), pelvic tissue prolapse (e.g., female vaginal prolapse), and conditions of the pelvic floor. 
     Urinary incontinence can further be classified as including different types, such as stress urinary incontinence (SUI), urge urinary incontinence, mixed urinary incontinence, among others. Other pelvic floor disorders include cystocele, rectocele, enterocele, and prolapse such as anal, uterine and vaginal vault prolapse. A cystocele is a hernia of the bladder, usually into the vagina and introitus. Pelvic disorders such as these can result from weakness or damage to normal pelvic support systems. 
     Urinary incontinence can be characterized by the loss or diminution in the ability to maintain the urethral sphincter closed as the bladder fills with urine. Male or female stress urinary incontinence (SUI) generally occurs when the patient is physically stressed. 
     In its severest forms, vaginal vault prolapse can result in the distension of the vaginal apex outside of the vagina. An enterocele is a vaginal hernia in which the peritoneal sac containing a portion of the small bowel extends into the rectovaginal space. Vaginal vault prolapse and enterocele represent challenging forms of pelvic disorders for surgeons. These procedures often involve lengthy surgical procedure times. 
     Urinary incontinence can be characterized by the loss or diminution in the ability to maintain the urethral sphincter closed as the bladder fills with urine. Male or female stress urinary incontinence (SUI) occurs when the patient is physically stressed. 
     Some patients can not receive other innovative or conventional sling or like incontinence procedures due to contraindications associated with general anesthesia, anticoagulant therapy, or other surgical solutions and approaches. 
     As such, there is a desire to obtain a minimally invasive yet highly effective system and method that can be used to treat urinary incontinence. 
     SUMMARY OF THE INVENTION 
     The present invention describes pelvic incontinence stents adapted to treat various forms of incontinence in males and females. Embodiments of the present invention are generally directed for use in patients experiencing incontinence and contraindication for other surgical interventions or procedures. 
     A urethral stent device can include a mechanical valve system, to be delivered up through the urethra via a flexible delivery tool. Embodiments can include a passive valve system adapted to open when exposed to a certain amount of intraluminal pressure and will generally remain open until a desired cessation of fluid flow is achieved. Other embodiments of the valve mechanism or system can be actuated via an external mechanism or device (e.g., manual manipulation, electrical, magnetic, electro-mechanical, etc.). 
     The valve mechanism of the device can include a pivoting valve assembly having a valve flange, a stopper member and a pivot portion. The flange and stopper are operably connected to the pivot portion and can be generally rigid in certain embodiments. The pivot portion can include a biasing member, such as a spring device, adapted to bias the flange toward a first closed portion. Upon reaching a threshold fluid flow pressure on the flange, the flange moves in a first direction against the resistance of the biasing member. This biasing pressure can be set with the tension or bias of the biasing member according to normal sphincter or like muscle resistance or closure tendencies of a normal urinary lumen. 
     As fluid and pressure builds up along fluid flow path and against the flange, the bias of biasing member resists the flow and continues to promote continence. At a higher threshold flow level (e.g., buildup of urine within the bladder and along the urethra to the device) the flange begins to move until the flange rests against an interior wall portion of the valve mechanism. As the flange moves toward the wall portion, the stopper member correspondingly moves away from its seated position along the seat wall portion. Upon complete pivoting motion of the flange to the wall the stopper member is fully unseated from its original position such that a new fluid flow is permitted through the valve mechanism. Namely, urine flow is permitted to flow through the stent device to permit voiding. 
     An advantage of the present invention can be seen when a patient can not receive other innovative or conventional sling or like incontinence procedures due to contraindications associated with general anesthesia, anticoagulant therapy, or other surgical solutions and approaches. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a urethral stent device for use in treating incontinence in accordance with embodiments of the present invention. 
         FIGS. 2-6  show various anatomical features and potential deployment sites for a urethral stent device for use in treating incontinence in accordance with embodiments of the present invention. 
         FIG. 7  shows a partial schematic sectional view of a urethral stent device in a closed position in accordance with embodiments of the present invention. 
         FIG. 8  shows a partial schematic sectional view of a urethral stent device in an open position in accordance with embodiments of the present invention. 
         FIG. 9  shows a delivery or introduction tool having a urethral stent device loaded therein in accordance with embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring generally to  FIGS. 1-9 , various embodiments of an implantable stent implant device and system  5  is shown. In general, an implantable stent implant  10  can include a first body portion  12   a , a second body portion  12   b , and a valve mechanism  14 . Various portions of the implant  10  can be constructed of polymer or compatible metal materials, such as polypropylene, polyethylene, fluoropolymers, Nitinol™ or other like materials. The implant device  10  can be constructed at least in part (e.g., portions  12   a ,  12   b ) of a biocompatible super alloy mesh tube adapted to provide expansion E along portions (e.g., portions  12   a ,  12   b ) of the device  10  due to shape memory properties. Namely, the portions  12   a ,  12   b  can self-expand to abut against an interior portion of the urethral wall upon deployment within the body lumen. 
     The various implants  10 , systems, features, devices, introducer and deployment tools, and methods detailed or disclosed (e.g., for male and female) in U.S. Pat. Nos. 7,500,945, 7,407,480, 7,351,197, 7,347,812, 7,303,525, 7,025,063, 6,926,732, 6,991,647, 6,691,711, t,471,718, 6,648,921, 6,612,977, 6,143,021, 5,499,994 and International Patent Publication Nos. WO 2008/057261 and WO 2007/097994, and U.S. Patent Publication Nos. 2010/0105979, 2002/151762 and 2002/147382 are envisioned for use, in whole or in part, with embodiments of the present invention; accordingly, the above-identified disclosures are fully incorporated herein by reference in their entirety. Further, deployment tools and stent devices (e.g., stent expansion characteristics) provided with the UroLume devices and systems, made and sold by American Medical Systems of Minnetonka, Minn., can be employed with the present invention. 
       FIGS. 2-6  show potential anatomical sites for implantation of the stent device  10  of the present invention. However, the device  10  can be placed along various select portions of the urethral lumen, within male or female patients, to provide continence for the patient while still permitting voiding as disclosed herein. 
     Referring generally to  FIGS. 7-8 , the valve mechanism  14  of the device  10  can include a pivoting valve assembly having a valve flange  20 , a stopper member  22  and a pivot portion  24 . The flange  20  and stopper  22  are operably connected to the pivot portion  24  and can be generally rigid in certain embodiments. The pivot portion  24  can include a biasing member  26 , such as a spring device, adapted to bias the flange toward a first closed portion as shown in  FIG. 7 . Upon reaching a threshold fluid flow pressure on the flange  20 , the flange  20  moves in the direction of or with the flow A, e.g., against the resistance of the biasing member  26 . This biasing pressure can be set with the tension or bias of the biasing member  26  according to normal sphincter or like muscle resistance or closure tendencies of a normal urinary lumen. 
     In general, two primary fluid flow paths are available. Namely, the device  10  is implanted within the urethral lumen of the patient, with the body portions  12   a ,  12   b  adapted to expand to securely abut the interior wall of the target urethra portion. Once installed, the valve mechanism  14  defaults in the closed position, as depicted in  FIG. 7 . The flange  20  is generally sealing against a top wall portion  23  and the stopper member  22  is seated against a seat wall portion  25 . As such, urinary flow A or fluid pressure hits the flange  20  but is not sufficient to move the flange  20 . As such fluid flow A is not permitted to exit out of the valve mechanism  14  to body portion  12   a  of the device. This is a state of continence for the patient. 
     As fluid and pressure builds up along fluid flow A and against the flange  20 , the bias of biasing member  26  resists the flow and continues to promote continence. At a higher threshold flow level (e.g., buildup of urine within the bladder and/or along the urethra to the device  10 , selective according to the spring or like biasing characteristics of the biasing member  26 ), the flange  20  begins to move with the flow A and toward the body portion  12   a  (e.g., at a break open force) until the flange  20  rests against interior wall portion  30  of the valve mechanism  14 . As the flange  20  moves toward the wall portion  30 , the stopper member  22  correspondingly moves away from its seated position along the seat wall portion  25 . Upon complete pivoting motion of the flange  20  to the wall  30 , as shown in  FIG. 8 , the stopper member  22  is unseated from its original position such that a new fluid flow B is permitted through the valve mechanism  14 . Namely, urine flow is permitted to flow from the body portion  12   b  to the body portion  12   b  via fluid path B to permit voiding through the urethra U. The biasing member  26  or pivoting portion  24  can include a detent mechanism or like mechanisms to facilitate or control release of the spring tension or the break open condition during the pivoting conditions disclosed herein. 
     Upon completion, or substantial completion, of the voiding process along fluid path B, pressure of the fluid flow reduces to the point where the biasing characteristics of the biasing member  26  can urge the flange  20  back toward its original position, as shown in  FIG. 7 , to cause a reset of the mechanism  14 . As such, the stopper member  25  again reseats at the wall portion  25  and fluid flow along path A is obtained to provide continence for the patient. 
     As described and depicted, the valve mechanism  14  can be passively actuated according to fluid flow. In other embodiments, the valve mechanism can be actuated (opening or closing—e.g., moving the flange  20  and/or member  22 ) by external means, including magnetic actuators, electrical actuators, mechanical actuators, electro-mechanical actuators, or other known external triggering sources, devices and techniques. 
     The valve housing can be a solid or semi-solid assembly. One or more bushings  34  can be included around a periphery or other portion of the valve mechanism  14  to generally reduce or eliminate expansion or movement of the mechanism  14  within the lumen of the urethra U. 
     As shown in  FIG. 9 , various adapted introducer tools  40  can be employed to introduce, deploy and manipulate the stent device  10 . The tool  16  can include a distal end  42  adapted to selectively receive or secure the device  10  therein, a handle  44  having one or more actuation portions  46  (e.g., trigger or actuators), and a tubing or shaft portion  48 . The tubing or shaft  48  can be generally flexible and in operable communication with the handle  44  and the device  10  to facilitate control and deployment of the device  10  within the urethra of the patient. In certain embodiments, the device  10  is pushed out of the shaft  48  at the distal end  42  once the distal end  42  is inserted and positioned at the target deployment site within the urethra U. While within the tool  40 , the device  10  (e.g., portions  12   a ,  12   b ) are in a generally compressed configuration. Once deployed from the distal end  42 , the device  10 , or portions  12   a ,  12   b  thereof, automatically expand to provide secure abutment of the device  10  against the interior wall portions of the urethra U to promote continence. 
     All patents, patent applications, and publications cited herein are hereby incorporated by reference in their entirety as if individually incorporated, and include those references incorporated within the identified patents, patent applications and publications. 
     Obviously, numerous modifications and variations of the present invention are possible in light of the teachings herein. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described herein.