US20090204055A1 - Treating urinary retention - Google Patents

Abstract

A urethral prosthesis provides relief of urinary retention and has first and second tubular elements with an interposed bridge segment. A valve can be disposed in the second tubular element to control the flow of urine therethrough.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• This incorporates by reference and claims priority to and the benefit of U.S. provisional patent application Ser. No. 60/104,390, filed Oct. 15, 1998.
TECHNICAL FIELD
• The invention relates generally to urethral prostheses and methods of insertion into a body. More particularly, the invention relates to a urethral prosthesis having a bladder/prostate segment and a penile urethra segment connected by a bridge segment, which crosses the urinary sphincter.
BACKGROUND INFORMATION
• Urinary retention in males is often caused by neurological disorders or by obstructions in the urinary tract. Neurogenic urinary retention is a condition in which a person is unable to empty his urinary bladder voluntarily due to a neurological dysfunction of the urinary bladder and/or of the urinary sphincter. Neurogenic urinary retention is due to an inability of the bladder to contract and/or of the urinary sphincter to relax. Patients with spinal cord injuries, multiple sclerosis, Parkinson's disease, or trauma to the pelvic region may suffer from neurogenic urinary retention on a permanent or transient basis.
• Patients suffering from neurogenic urinary retention generally have limited options for draining their bladders. These include using a Foley catheter, intermittent catheterization, and a suprapubic drainage tube. All three options have high infection rates, are inconvenient for the patient and/or care giver, are uncomfortable for the patient, and cause the patient emotional distress.
• Urinary retention is also caused by obstructions in the urethra, such as prostatic obstructions. The prostate gland encircles the urethra immediately below the urinary bladder. A common affliction among older males is benign prostatic hyperplasia (BPH), or the nonmalignant enlargement of the prostate. When the prostate becomes enlarged, it may restrict the urethra and thereby obstruct the flow of urine from the bladder.
• A common treatment of BPH is surgical resection of the prostate and urethral tissue, but this option is not suitable for many patients. BPH afflicts primarily older males, so other health problems, such as cardiovascular disease, may prevent surgical intervention. Furthermore, potential complications associated with surgery, such as urinary infection, dysuria, and incontinence, may make a patient unwilling to undergo the surgery.
SUMMARY OF THE INVENTION
• It is an object of the invention to relieve the symptoms of urinary retention in males without the high infection rates and other potential complications associated with current treatments. It is another object of the invention to provide a urethral prosthesis that resides within a bladder and urethra of a patient and that provides the patient control over drainage of the bladder without the discomfort and emotional distress associated with conventional treatments.
• In one aspect, the invention relates to a urethral prosthesis including a first tubular element, a second tubular element, a bridge segment for joining the first and second tubular elements, and a valve. The first tubular element includes a distal portion with a drainage hole for receiving urine, a proximal end and a lumen, which extends from the drainage hole through the first tubular element to the proximal end of the first tubular element. At least a portion of the first tubular element is adapted for residing in a urethra of a patient. The second tubular element is adapted for residing in a penile urethra of a patient. The second tubular element includes a lumen extending from the bridge segment to its proximal end. The bridge segment has a diameter that is smaller than the diameter of the first tubular element and has a lumen for providing a permanent urine flow channel from the first tubular element through the urinary sphincter. The valve is disposed within the lumen of the second tubular element for controlling a flow of urine through the lumen of the second tubular element.
• Embodiments according to this aspect of the invention can include the following additional features. The first and second tubular elements and the bridge segment may all be made of a pliable, biocompatible material, such as silicone rubber, for example. In another embodiment, the bridge segment comprises a spring disposed within the pliable, biocompatible material. In another embodiment, the proximal end of the second tubular element contains a suture wire to aid in removing the prosthesis from the urethra of a patient. The first and second tubular elements may also have an external surface coated with a coating including a plurality of gas bubbles therein.
• In this aspect of the invention, the valve may be a magnetically-actuatable valve. In this embodiment, the valve includes a ferromagnetic valve seat, which has an aperture for the passage of fluid therethrough, and a valve element. The valve element includes a magnet encapsulated in a non-magnetic capsule. The capsule has a top portion and a base portion, which is wider than the top portion. The valve element is magnetically attracted to the valve seat so that it blocks the flow of fluid through the aperture in the valve seat.
• In a second aspect, the invention relates to a urethral prosthesis including a first tubular element, a second tubular element, and a bridge segment of suture wires connecting the first and second tubular elements. The bridge segment resides within the urinary sphincter. The first tubular element has a drainage hole for receiving urine in its distal portion, a lumen extending from the drainage hole to its proximal end, and an external surface coated with a coating including a plurality of gas bubbles disposed therein. The first tubular element is adapted for residing at least partially in the urethra of a patient. The second tubular element is adapted for residing in a penile urethra of the patient and has a lumen.
• Embodiments according to this aspect of the invention can include the following additional features. The second tubular element may also have an external surface coated with a coating including a plurality of gas bubbles. The first and second tubular elements may be composed of a pliable, biocompatible material, such as silicone rubber, for example. The second tubular element may include a suture wire attached to its proximal end to aid in removing the prosthesis from the patient. Finally, the second tubular element may include an optical lens embedded in its wall.
• In a third aspect, the invention relates to a urethral prosthesis including a first tubular element, a second tubular element, and a bridge segment of suture wires connecting the first and second tubular elements. The bridge segment resides within the urinary sphincter. The first tubular element has a drainage hole for receiving urine in its distal portion, and a lumen extending from the drainage hole to its proximal end. The first tubular element is adapted for residing at least partially in the urethra of a patient. The second tubular element is adapted for residing in a penile urethra of the patient and has a lumen and includes an optical lens embedded in its wall.
• Embodiments according to this aspect of the invention can include the following additional features. The first and second tubular element may also have an external surface coated with a coating including a plurality of gas bubbles. The first and second tubular elements may be composed of a pliable, biocompatible material, such as silicone rubber, for example. The second tubular element may include a suture wire attached to its proximal end to aid in removing the prosthesis from the patient.
• The invention also relates to systems and methods for treating urinary retention. A system of the invention includes a urethral prosthesis of any of the above-described embodiments, an inflation cannula, and an inflatable balloon. The inflation cannula includes a lumen, which is in communication with the inflatable balloon for passage of fluid or gas to the balloon, so as to inflate the balloon. In one embodiment, the balloon covers at least a portion of the first tubular element when inflated. In another embodiment, the balloon covers the second tubular element when inflated.
• A method of using such a system in which the balloon covers at least a portion of the first tubular element includes inserting the prosthesis in a urethra of a patient, pushing the prosthesis within the urethra so that the drainage hole is positioned in a bladder of the patient, delivering a volume of fluid or gas to the balloon through the inflation cannula so as to inflate the balloon, and withdrawing the prosthesis until a resistance is felt. This resistance indicates that the bridge segment of the prosthesis is positioned within the urinary sphincter.
• A method of using such a system in which the balloon covers the second tubular element includes inserting the prosthesis in a urethra of a patient, pushing the prosthesis within the urethra until a first resistance is felt, delivering a volume of fluid or gas to the balloon through the inflation cannula so as to inflate the balloon, and pushing the prosthesis farther into the urethra until a second resistance is felt. This second resistance indicates that the bridge segment of the prosthesis is positioned within the urinary sphincter of the patient.
• In an alternative embodiment of the method, the first and/or second tubular elements have an external surface coated with a coating including a plurality of gas bubbles. The method then further includes imaging the first and/or second tubular elements by ultrasound.
• In alternative embodiments of the systems described above, a transducer is disposed within the balloon. A method of using such a system in which the balloon covers at least a portion of the first tubular element includes the steps of inserting the prosthesis in a urethra of a patient, pushing the prosthesis within the urethra so that the drainage hole is positioned in a bladder of the patient, delivering a volume of fluid or gas to the balloon through the inflation cannula so as to inflate the balloon, and withdrawing the prosthesis until a marked increase occurs in the pressure. This marked increase in pressure indicates that the bridge segment of the prosthesis is positioned within the urinary sphincter.
• A method using such a system in which the balloon covers the second tubular element includes the steps of inserting the prosthesis within a urethra of a patient, pushing the prosthesis within the urethra until a first resistance is felt, delivering a volume of fluid to the balloon via the inflation cannula, monitoring a pressure of the balloon via the transducer, and pushing the prosthesis farther into the urethra until a marked increase occurs in the pressure. This marked increase indicates that the bridge segment is positioned within the urinary sphincter.
• Methods of inserting a urethral prosthesis using such a system include inserting the urethral prosthesis into a urethra of the patient, pushing the prosthesis within the urethra until a first resistance is felt, delivering a volume of fluid via the inflation cannula to the inflatable balloon, so as to inflate the balloon, and pushing until a second resistance is felt. In an alternative embodiment, pressure in the balloon is monitored via a transducer, which is disposed within the balloon.
• In an alternative embodiment of the above method, the first and/or second tubular elements have an external surface coated with a coating including a plurality of gas bubbles. The method then further includes imaging the first and/or second tubular elements by ultrasound. In an additional alternative embodiment, a transducer is inserted within the lumen of the second tubular element of the prosthesis for imaging the prosthesis by ultrasound and confirming that the bridge segment is properly positioned so that it spans the urinary sphincter. The ultrasound transducer may also be advanced into the lumen of the first tubular element after passing through the bridge segment, so as to confirm placement of the drainage hole in the bladder.
• Another method of inserting a urethral prosthesis includes inserting a urethral prosthesis of any of the above-described embodiments into a urethra of a patient until the drainage hole of the first tubular element resides in the bladder and withdrawing the prosthesis until a resistance is felt. Embodiments of this method can include the following additional features. The external surface of the first and/or second tubular elements include an external surface coated with a coating including a plurality of gas bubbles. The method then further includes imaging the first and/or second tubular elements by ultrasound. In an additional alternative embodiment, a transducer is inserted within the lumen of the second tubular element of the prosthesis for imaging the prosthesis by ultrasound and confirming that the bridge segment is properly positioned so that it spans the urinary sphincter. The ultrasound transducer may also be advanced into the lumen of the first tubular element after passing through the bridge segment, so as to confirm placement of the drainage hole in the bladder.
• Another method of inserting a urethral prosthesis includes inserting a urethral prosthesis of any of the above-described embodiments into a urethra of a patient and viewing the bridge segment of the prosthesis with an optical lens, so as to position the bridge segment within the urinary sphincter of the patient. In an alternative embodiment, the method also includes irrigating the urethra.
• In other alternative embodiments of the method, the optical lens is an endoscope. The endoscope can be adapted for sliding within an external groove of the second tubular element. Also, the optical lens may be adapted for passing through the lumen of the second tubular element. Alternatively, the optical lens may be embedded within a wall of the second tubular element. Finally, the external surface of the first and/or second tubular elements include an external surface coated with a coating including a plurality of gas bubbles. The method then further includes imaging the first and/or second tubular elements by ultrasound. In an additional alternative embodiment, a transducer is inserted within the lumen of the second tubular element of the prosthesis for imaging the prosthesis by ultrasound and confirming that the bridge segment is properly positioned so that it spans the urinary sphincter. The ultrasound transducer may also be advanced into the lumen of the first tubular element after passing through the bridge segment, so as to confirm placement of the drainage hole in the bladder.
• The foregoing and other objects, aspects, features, and advantages of the invention will become more apparent from the following description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
• In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.
• FIG. 1 is an illustration of an embodiment of a urethral prosthesis of the invention for use in treating neurogenic urinary retention.
• FIG. 2 shows the urethral prosthesis ofFIG. 1 residing in a urethra of a patient.
• FIG. 3A is an illustration of a valve for use in a urethral prosthesis of the invention in its closed state.
• FIG. 3B is an illustration of a valve for use in a urethral prosthesis of the invention in its open state.
• FIG. 4 is an illustration of an embodiment of a urethral prosthesis of the invention for use in treating urinary retention due to obstructions in the urethra.
• FIG. 5 shows a urethral prosthesis ofFIG. 4 residing in a urethra of a patient.
• FIG. 6 is a cross-sectional view of a second tubular element of a prosthesis of the invention containing an optical lens embedded in its wall.
• FIG. 7 is an illustration of a configuration for use in inserting a urethral prosthesis of the invention.
• FIG. 8A is an illustration of a configuration for inserting a urethral prosthesis of the invention using an inflatable balloon that covers the second tubular element.
• FIG. 8B is an illustration of the configuration ofFIG. 8A in which the balloon is inflated.
• FIG. 8C is an illustration of a positioning stylet for use in methods of the invention.
• FIGS. 9A-9D are illustrations of a method of inserting a urethral prosthesis of the invention using a system ofFIGS. 8A-8C.
• FIG. 10A is an illustration of a configuration for inserting a urethral prosthesis of the invention using an inflatable balloon that covers at least a portion of the first tubular element.
• FIG. 10B is an illustration of the configuration ofFIG. 10A in which the balloon is inflated.
• FIGS. 11A-11C are illustrations of a method of inserting a urethral prosthesis of the invention using a system ofFIGS. 10A-10B.
• FIG. 12 is an illustration of a system for use in inserting a urethral prosthesis of the invention using a transducer to monitor changes in pressure of the balloon.
• FIG. 13A is an illustration of a configuration for inserting a urethral prosthesis of the invention using an endoscope.
• FIG. 13B is a cross-sectional view, taken alongline13B-13B inFIG. 13A, of the urethral prosthesis which has an external groove for accommodating the endoscope.
• FIG. 14 is an illustration of a positioning stylet having fluid delivery ports.
• FIG. 15A is a cross-sectional view of a second tubular element of a urethral prosthesis of the invention having an optical lens embedded in its wall and a positioning stylet positioned within its lumen, such as the stylet ofFIG. 14.
• FIG. 15B is a cross-sectional view of a second tubular element of a urethral prosthesis of the invention having an endoscope and a positioning stylet positioned within its lumen.
DESCRIPTION
• The invention relates to a urethral prosthesis for providing relief of urinary retention. A urethral prosthesis of the invention includes first and second tubular elements with an interposed bridge segment. The first and second tubular elements both have lumens extending therethrough. The bridge segment can be a generally non-compressible section with a diameter smaller than the diameter of each of the first and second tubular elements. Alternatively, the bridge segment can comprise at least one suture extending between the two tubular elements. A valve can be disposed in the lumen of the second tubular element, so as to control the flow of urine through the second tubular element.
• When inserted into a patient, a drainage hole in the first tubular element resides within or near the patient's bladder, the remainder of the first tubular element resides within the prostatic urethra, the bridge segment passes through the urinary sphincter, and the second tubular element resides within the penile urethra. A urethral prosthesis of the invention therefore provides a channel for the flow of urine from the bladder out of the patient's body.
• Systems and methods are also provided for the treatment of urinary retention using a urethral prosthesis, such as the types of prostheses described above. A system and method of the invention provides for the use of an inflatable balloon to locate the urinary sphincter and thereby ensure proper positioning of the urethral prosthesis of the invention. Other methods ensure proper positioning by detecting resistance or by viewing the urinary sphincter with an optical lens during insertion.
• An embodiment of a urethral prosthesis of the invention for use in treatment of neurogenic urinary retention is illustrated inFIG. 1. Theprosthesis9 includes a firsttubular element10, abridge segment12, and a secondtubular element14. The firsttubular element10 and the secondtubular element14 may be composed of any pliable biocompatible material, such as silicone rubber, for example. In one embodiment, the firsttubular element10 and the secondtubular element14 each has a lumen that is circular in cross-sectional shape. In an alternative embodiment, the lumen of the firsttubular element10 and the lumen of the secondtubular element14 are not circular in cross-sectional shape and may comprise a C-shape or a semi-circular shape, for example. The external surfaces of the firsttubular element10 and the second tubular14 may be modified accordingly in order to create the non-circular shapes.
• In some embodiments, the external surfaces of both the firsttubular element10 and the secondtubular element14 are coated with a plastic coating, such as a silicone coating, which is impregnated with gas bubbles. This coating makes the prosthesis echogenic, so that ultrasound may be used to ensure proper positioning of the prosthesis during insertion or to confirm proper placement of the prosthesis after it is inserted.
• The firsttubular element10 and the secondtubular element14 both have lumens and are open at their proximal ends. The secondtubular element14 is also open at its distal end. The distal end of the firsttubular element10 is closed, but adrainage hole16 is provided near the distal end. Thebridge segment12 has a reduced diameter as compared to the firsttubular element10 and the secondtubular element14. Disposed within thebridge segment12 is aspring18. The secondtubular element14 includes avalve20 andsuture wires22. Thesesuture wires22 aid in removal of the prosthesis from the urethra of the patient. The prosthesis may be removed by pulling onsuture wires22. Thesuture wires22 can be made of thin strands of a polymeric material, of silicone, metal, plastic, or rubber. Thesuture wires22 may also be braided or monofilaments.
• The separate sections of theurethral prosthesis9 shown inFIG. 1 are adapted for positioning within different segments of the urethra and the bladder.FIG. 2 is an illustration of theurethral prosthesis9 in a urethra of a patient. The firsttubular element10 is inserted so that thedrainage hole16 resides within thebladder24 of the patient. The remainder of the firsttubular element10 spans the prostatic urethra, which is identified as that portion of the urethra surrounded by theprostate26. Thebridge segment12 spans theurinary sphincter28, so as to provide a permanently open channel through which urine from the bladder can flow into the secondtubular element14, which resides in thepenile urethra30.
• In one embodiment, thebridge segment12 is non-compressible so as to hold the urinary sphincter in an open position and thereby provide a permanently open channel for the flow of urine from thebladder24. Thebridge segment12 may be composed of any pliable biocompatible material, such as silicone rubber, for example. Patients suffering from neurogenic urinary retention are unable to control the opening and closing of the urinary sphincter and/or are unable to contract the bladder. By providing an open channel for the flow of urine across the urinary sphincter, these problems are alleviated. Furthermore, thebridge segment12 includes thespring18, which imparts flexibility to thebridge segment12, thereby increasing the comfort level of the patient. Thesuture wires22 extend into thepenile urethra30, where they may be grasped and pulled in order to remove theprosthesis9 from the urethra of the patient.
• To control the flow of urine through the secondtubular element14 and out of the body, avalve20 is disposed within the secondtubular element14. A suitable valve for use in a urethral prosthesis, as described above, is as described in U.S. Pat. No. 5,366,506, the entire disclosure of which is hereby incorporated by reference herein. In one embodiment, as shown inFIG. 3A, a valve includes aferromagnetic valve seat32, which includesapertures34 and34′. Thevalve20 also includes avalve element38, which includes amagnet36. The walls of thevalve element38 are non-magnetic. As shown inFIG. 3A, the bottom portion of thevalve element38 is wider than the top portion of thevalve element38. Absent any external force, thevalve element38 is magnetically attracted to thevalve seat32, thereby blocking theaperture34. Thevalve20 is therefore in its closed position and fluid cannot flow through it. When an external magnetic force is applied to thevalve20, such as by contacting an exterior of a penis in which such a valve resides with a magnet, thevalve element38 is displaced so as to open theaperture34, as is shown inFIG. 3B. In the open position, fluid flows into thevalve20 through theaperture34′ and then through theaperture34 to the remainder of thepenile urethra30, and then out of the body.
• An embodiment of aurethral prosthesis39 of the invention for use in treating urinary retention due to an obstruction in the urethra is shown inFIG. 4. In this embodiment, the firsttubular element10 and the secondtubular element14 are as described above. The firsttubular element10 has a closed distal end, except for adrainage hole16. In this embodiment of the invention, thebridge segment12 includessuture wires40.
• In the case of urinary retention due to an obstruction in the urethra, patients have the ability to control their urinary sphincters and bladder contractions. A bridge segment that maintains a permanent flow channel is therefore not required. This embodiment of the invention therefore allows the patient to control the urinary sphincter, while the prosthesis otherwise maintains an open channel in the urethra. An illustration of aprosthesis39 in a patient is shown inFIG. 5. Obstructions of the urethra commonly occur when theprostate26 becomes enlarged and restricts the prostatic urethra, thereby blocking it. As can be seen inFIG. 5, the firsttubular element10 resides with itsdrainage hole16 in thebladder24, and with the remainder of the firsttubular element10 spanning the prostatic urethra. The firsttubular element10 therefore serves to maintain an open channel for the flow of urine through the prostatic urethra. When theurinary sphincter28 is closed, thesuture wires40 are compressed. When theurinary sphincter28 is open, urine flows into the secondtubular element14 and through thepenile urethra30 to the exterior of the body.
• In one embodiment of theurethral prosthesis39, as shown inFIG. 4, the firsttubular element10 and the secondtubular element14 are composed of a pliable, biocompatible material, such as silicone rubber. In another embodiment, the firsttubular element10 and the secondtubular element14 have external surfaces coated with a plastic coating including a plurality of gas bubbles. As described above, this echogenic coating provides for ultrasound imaging of the device during or after insertion. Theprosthesis39 also containssuture wires22, which aid in removing theprosthesis39 from the patient, also as described above.
• In an alternative embodiment of a urethral prosthesis for relieving urinary retention due to obstructions in the urethra, an optical lens is embedded within the wall of the secondtubular element14.FIG. 6 shows a cross-sectional view of a secondtubular element14 having anoptical lens42 embedded within its wall. Theoptical lens42 may be used to ensure proper placement of the prosthesis during insertion. In one embodiment, theoptical lens42 is disposed at the distal end of the secondtubular element14, so that theurinary sphincter28 may be viewed during the insertion procedure. (This insertion procedure is described in more detail below.) The first and second tubular elements of a urethral prosthesis containing an optical lens embedded within the wall of the second tubular element may or may not have external surfaces coated with an echogenic coating, as described above.
• Methods of the invention relate to the insertion of a urethral prosthesis in a urethra and bladder of a patient. Methods the invention may include the use of any of the urethral prostheses described above. One such configuration for inserting a urethral prosthesis is shown inFIG. 7. The configuration inFIG. 7 includes theurethral prosthesis9, theinsertion sleeve44, and theretractor46. Theinsertion sleeve44 is disposed over the secondtubular element14 and thebridge segment12, and is partially disposed over the firsttubular element10. Theretractor46 is releasably attached to the proximal end of the secondtubular element14. The configuration ofFIG. 7 is shown with theprosthesis9 by way of example only. The kit may also be used in conjunction with theprosthesis39, or any of the above-described embodiments ofprostheses9 and39.
• A method of insertion of a urethral prosthesis involves inserting theprosthesis9, theinsertion sleeve44, and theretractor46 into a urethra of a patient. The distal end of the firsttubular element10 is inserted first. Theprosthesis9 is inserted so that thedrainage hole16 resides in thebladder24 of the patient, as shown inFIG. 2. If the first tubular element has an echogenic coating, the firsttubular element10 with thedrainage hole16 in thebladder24 may be imaged with ultrasound, as described above. Alternatively, the placement of theprosthesis9 may be imaged by inserting an ultrasound transducer into the lumen of the secondtubular element14. The ultrasound transducer may also be advanced through thebridge segment12 of theprosthesis9 and into the lumen of the firsttubular element10, so as to view the placement of the first tubular element within thebladder24. Theinsertion sleeve44 is then removed, and theretractor46 is used to pull theprosthesis9 back toward the opening of the urethra until a resistance is felt by the user. This resistance indicates that thebridge segment12 is properly positioned in theurinary sphincter28, as shown inFIG. 2. Theretractor46 is then disengaged from the secondtubular element14 and removed from the urethra. Proper positioning of the prosthesis may be confirmed with urethroscopy or ultrasound as described above.
• A system of the invention is shown inFIGS. 8A-8C. The system contains theprosthesis39, apusher48, apositioning stylet50, aninflation cannula52, and aninflatable balloon54. Thepusher48 is sized and shaped for butting up against the proximal end of the secondtubular element14, so that it pushes against the secondtubular element14 and thereby advances theprosthesis39 into a urethra of a patient. Thepusher48 has a lumen for insertion of thepositioning stylet50 therein. An illustration of thepositioning stylet50 is shown inFIG. 8C. Thepositioning stylet50 is adapted to reside within the lumens of thepusher48, the secondtubular element14, and the firsttubular element10, so as to maintain theprosthesis39 in its extended position during the insertion procedure. Without thestylet50,suture wires40 may become bent, twisted, or collapsed during insertion.
• Theinflation cannula52 ofFIG. 8A also has a lumen, which is in communication with theinflatable balloon54. To inflate theballoon54, fluid or gas is delivered through the lumen of theinflation cannula52. Theballoon54 is disposed over the secondtubular element14. InFIG. 8A, theballoon54 is not inflated.FIG. 8B is an illustration of the system in which theballoon54 is inflated over the secondtubular element14. Theballoon54 may be compliant or non-compliant. Balloons are standardized so that the injection of a known amount of fluid within the balloon induces inflation of the balloon to a specific diameter. Balloons may also be standardized with respect to diameter and pressure. Once the system ofFIGS. 8A-8C is closed, a relation exists between the pressure within the system and the diameter of the balloon. The system is shown with theprosthesis39 by way of example only. The system may also be used in conjunction with theprosthesis9, or any of the above-described embodiments ofprostheses9 and39.
• A method for inserting a prosthesis using the system shown inFIGS. 8A-8C is shown inFIGS. 9A-9D. In this method, theprosthesis39, thepositioning stylet50, thepusher48, theinflation cannula52, and theballoon54 are inserted into a urethra of a patient, with the distal end of the firsttubular element10 being inserted first. Theprosthesis39 is pushed by thepusher48, along with thepositioning stylet50, until a first resistance is felt. This first resistance indicates that the distal end of the firsttubular element10 has contacted theurinary sphincter28, as shown inFIG. 9A. Theballoon54 is then inflated by delivering fluid or gas via theinflation cannula52 to the interior of theballoon54. Theballoon54 inflates over the secondtubular element14, as shown inFIG. 9B. Theprosthesis39 is then pushed farther into the urethra until a second resistance is felt. This second resistance indicates that theballoon54 has contacted theurinary sphincter28, as shown inFIG. 9C. Thepusher48 and theinflation cannula52 are removed from the urethra so as to deflate theballoon54. At this point, theprosthesis39 is properly positioned within the urethra of the patient, such that thedrainage hole16 is residing in thebladder24 and thebridge segment12 spans theurinary sphincter28, as shown inFIG. 9D. Proper placement of the prosthesis may be confirmed by urethroscopy or ultrasound, as described above.
• An alternative system of the invention is shown inFIGS. 10A-10B. The system shown inFIG. 10A contains theprosthesis39, apusher48, aninflation cannula49, and aninflatable balloon51. Thepusher48 is sized and shaped for butting up against the proximal end of the secondtubular element14, so that it pushes against the secondtubular element14 and thereby advances theprosthesis39 into a urethra of a patient. Thepusher48 has a lumen for insertion of theinflation cannula49 therein. The inflation cannula is adapted to reside within the lumens of thepusher48, the secondtubular element14, and the firsttubular element10. Theinflation cannula49 also has a lumen, which is in communication with theinflatable balloon51 so as to deliver a volume of fluid or gas to theballoon51 and thereby inflate theballoon51. As shown inFIG. 10B, theballoon51 covers at least a portion of the firsttubular element10 when it is inflated. Theballoon51 is inflated at a position on the firsttubular element10 that resides in the bladder of a patient just above the prostate gland when inserted.
• A method for inserting a prosthesis using the system shown inFIGS. 10A-10B is shown inFIGS. 11A-11C. In this method, theprosthesis39 thepusher48, theinflation cannula49, and theballoon51 are inserted into a urethra of a patient, with the distal end of the firsttubular element10 being inserted first, as shown inFIG. 11A. The prosthesis is pushed by thepusher48, along with theinflation cannula49, until thedrainage hole16 of the firsttubular element10 is positioned within thebladder24, as shown inFIG. 11B. Theballoon51 is then inflated by delivering a volume of fluid or gas via theinflation cannula49 to the interior of theballoon51. Theballoon51 inflates over at least a portion of the firsttubular element10, as shown inFIG. 1 IC. Theprosthesis39 is then withdrawn (such as, for example, by using a retractor, as inFIG. 7) until a resistance is felt. This resistance indicates that theballoon51 is contacting theopening53 of thebladder24 just above theprostate26. This indicates that the prosthesis is properly positioned so that thebridge segment12 spans theurinary sphincter28. Proper placement of the prosthesis may be confirmed by urethroscopy or ultrasound, as described above.
• In an alternative embodiment of the system ofFIGS. 8A-8C, as shown inFIG. 12, a transducer (not shown) is disposed within theballoon54. The location of the transducer within the closed system is unimportant as long as it is located within and senses changes in pressure within the area containing the fluid or gas. The transducer is in electrical communication via the connectingwire51 with thecontroller53. Thecontroller53 monitors variations in pressure. Thecontroller53 includes anindicator55, which displays aplot59 of the changes in pressure as a function of time or as a function of distance of insertion into the urethra.Indicator55 may be a video monitor or a print-out display, for example. A marked increase inpressure57, indicates that theballoon54 has contacted theurinary sphincter28. Detection of the location of theurinary sphincter28 is then made by a visual reading of theplot59, so as to ensure accurate placement of theprosthesis39. Alternatively, when the balloon used is a compliant balloon, theplot59 may be standardized to yield a defined pressure for a specific diameter for a known volume of inflation fluid. Alternatively, the embodiment of the system shown inFIGS. 10A-10B may be similarly adapted. For example, a transducer may be disposed withinballoon51 and may indicate placement of theprosthesis39 by detecting marked increases in pressure as theprosthesis39 is withdrawn from the urethra.
• In an alternative embodiment, the system shown inFIG. 12 is used to measure the competency of the sphincter or detrusor muscles. This is accomplished by passing theballoon54 with a known freestanding pressure-volume curve into the desired location and incrementally inflating it with known volumes of fluid. After each inflation of theballoon54, a pressure measurement is taken and a pressure volume curve generated. By calculating the area difference between the curves, the net amount of work done by the sphincter is obtained.
• In another alternative embodiment, the system ofFIG. 12 is used to determine adequate bulking pressures or volumes used during bulking procedures to remediate sphincter incontinence, for example. The system may be used to monitor the injection of agents typically used to bulk sphincters and create constrictions, such as to treat stress incontinence (AUS, Collagen products) or GERD. By placing aballoon54 with the transducer in the desired position to be bulked, one can then monitor the compliance of the restriction created with the agent as it is injected. Clinical outcomes can be correlated to the compliance measured with this device to determine how much bulking agent is needed for the desired outcome.
• The system ofFIG. 12 may also have applications in urodynamic measurements, such as, compliance of body tissues within the urinary tract, arterial stenosis, aneurysm detection, or other areas where stricture, enlargement, or body tissue compliance quantification is pertinent.
• Another configuration for insertion of a urethral prosthesis is shown inFIGS. 13A-13B. This configuration includes theprosthesis39, thepusher48, thepositioning stylet50, and anendoscope56. Thepositioning stylet50 has a lumen and containsfluid delivery ports58, which are positioned to deliver fluid through thebridge segment12 during the insertion procedure. Irrigating the insertion site during the insertion procedure is necessary to keep theoptical lens42 of theendoscope56 clear for viewing. Thepositioning stylet50 withdelivery ports58 is illustrated inFIG. 14.
• In the configuration ofFIGS. 13A-13B, the secondtubular element14 and thepusher48 both have external grooves to allow theendoscope56 to slide along the external surface of both the secondtubular element14 and thepusher48. A cross-sectional view of the secondtubular element14 having an external groove is shown inFIG. 13B. As shown inFIG. 13B, theendoscope56 fits within the external groove of the secondtubular element14. Also shown in the lumen of the secondtubular element14 is thepositioning stylet50. The configuration is shown with theprosthesis39 by way of example only. The configuration may also be used in conjunction with theprosthesis9, or any of the above-described embodiments ofprostheses9 and39.
• In alternative embodiments of this configuration, theoptical lens42 is embedded within the wall of the secondtubular element14, as shown inFIG. 15A.FIG. 15A is a cross-sectional view of the secondtubular element14. In this embodiment, the secondtubular element14 and thepusher48 do not have external grooves. Also shown inFIG. 15A is thepositioning stylet50 within the lumen of the secondtubular element14. In another alternative embodiment, both theendoscope56 and thepositioning stylet50 are adapted to fit within the lumen of the secondtubular element14, as shown inFIG. 15B.
• A method of inserting aurethral prosthesis39 using such a configuration include inserting theprosthesis39, thepusher48, thepositioning stylet50, and theendoscope56 into a urethra of a patient. The distal end of the firsttubular element10 is inserted first, and theprosthesis39 is advanced farther into the urethra by pushing against the proximal end of the secondtubular element14 with thepusher48 and by pushing with thepositioning stylet50. While pushing theprosthesis39 into the urethra, theendoscope56 is used to view thebridge segment12. In one embodiment, the urethra is irrigated by delivering a fluid through the lumen of thepositioning stylet50 and through thefluid delivery ports58. The fluid may be any biological compatible fluid, such as saline, for example.
• In this method of insertion, thebridge segment12 is viewed with theendoscope56 to determine when thebridge segment12 is positioned such that it spans theurinary sphincter28, as shown inFIG. 5. Thepositioning stylet50, thepusher48, and theendoscope56 are then removed from the urethra. If the secondtubular element14 includes theoptical lens42 embedded within its wall, the method does not require use of theendoscope56 for viewing. Thebridge segment12 is viewed with the embeddedoptical lens42. Proper placement of the prosthesis may be confirmed by urethroscopy or ultrasound, as described above.
• The above described systems and methods provide the patient control over the draining of the bladder. Urethral prostheses of the invention may also be used in situations where it is not desirable or possible for the patient to have control over the draining of the bladder. In such circumstances, the distal end of the first tubular element of the prosthesis may be open, and a catheter, such as a Foley catheter, for example, may be inserted through the lumens of the second tubular element, bridge segment, and first tubular element of the prosthesis. The catheter can then be attached to a urine collection bag and meter. This embodiment allows for the monitoring of urine production by the patient.
• Variations, modifications, and other implementations of what is described herein will occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the invention is to be defined not by the preceding illustrative description but instead by the spirit and scope of the following claims.

Claims (21)

1-95. (canceled)

96. A urethral prosthesis, comprising:

a tubular element including a distal portion and a closed distal end, the distal portion defining a drainage hole for receiving urine from a bladder of a patient, the tubular element further including a proximal end and a lumen extending from the drainage hole through the tubular element to the proximal end, the tubular element further including an inflation balloon, the tubular element configured to maintain an open channel for fluid flow through a prostatic urethra of the patient when the prosthesis is positioned within the patient; and

an element coupled to the tubular element, the element including a spring member disposed within a pliable material.

97. The urethral prosthesis ofclaim 96, wherein the element is coupled directly to the tubular element.

98. The urethral prosthesis ofclaim 96, wherein the element extends proximally from the tubular element.

99. The urethral prosthesis ofclaim 96, wherein the inflation balloon is disposed near the drainage hole.

100. The urethral prosthesis ofclaim 96, wherein the inflation balloon is disposed on the tubular element.

101. The urethral prosthesis ofclaim 96, wherein the inflation balloon is inflatable over at least a portion of the tubular element.

102. The urethral prosthesis ofclaim 96, wherein the tubular element comprises a pliable, biocompatible material.

103. The urethral prosthesis ofclaim 96, wherein the tubular element includes a silicone coating.

104. The urethral prosthesis ofclaim 96, wherein the tubular element comprises silicone rubber.

105. The urethral prosthesis ofclaim 96, further comprising at least one removal suture.

106. The urethral prosthesis ofclaim 105, wherein the at least one removal suture is connected to the tubular element.

107. The urethral prosthesis ofclaim 105, wherein the at least one removal suture is connected to the element.

108. A urethral prosthesis, comprising:

(a) a tubular element including a distal portion and a closed distal end, the distal portion defining a drainage hole for receiving urine from a bladder of a patient, the tubular element further including a proximal end and a lumen extending from the drainage hole through the tubular element to the proximal end, the tubular element further including a length defined between the proximal end and the distal end, the tubular element configured to maintain an open channel for fluid flow through a prostatic urethra of the patient when the prosthesis is positioned within the patient;

(b) an inflation balloon disposed on the tubular element;

(c) at least one suture extending from the proximal end of the tubular element, the at least one suture passing through a urinary sphincter of the patient when the prosthesis is positioned within the patient to allow the patient to control the urinary sphincter; and

(d) a non-inflatable element extending from a proximal end of the at least one suture, the non-inflatable element including a proximal end and a distal end and defining a length between the proximal end and the distal end, the length of the tubular element being greater than the length of the non-inflatable element.

109. The urethral prosthesis ofclaim 108, wherein the distal end of the non-inflatable element has an outer diameter greater than an outer diameter of the proximal end of the element.

110. The urethral prosthesis ofclaim 108, wherein the non-inflatable element is configured to be disposed within a penile urethra.

111. The urethral prosthesis ofclaim 108, wherein the non-inflatable element has a width and is configured to substantially maintain the width during both insertion and while maintained within a urethra.

112. The urethral prosthesis ofclaim 108, further comprising at least one removal suture coupled to at least one of the non-inflatable element or the tubular element.

113. The urethral prosthesis ofclaim 108, wherein the inflation balloon is disposed near the drainage hole.

114. The urethral prosthesis ofclaim 108, wherein the tubular element comprises a pliable, biocompatible material.

115. The urethral prosthesis ofclaim 108, wherein the tubular element comprises silicone rubber.

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