WO2000025848A2

WO2000025848A2 - Prostatic tissue dilation balloon catheter

Info

Publication number: WO2000025848A2
Application number: PCT/US1999/025602
Authority: WO
Inventors: Terence M. Fogarty; Marvin B. Brooks; Steven N. Willard
Original assignee: Mentor Corporation
Priority date: 1998-11-02
Filing date: 1999-11-01
Publication date: 2000-05-11
Also published as: WO2000025848A3

Abstract

A prostatic tissue expander can include a urethral catheter, a positioning balloon disposed about the urethral catheter, an expander balloon disposed about the urethral catheter, and a containment assembly disposed about the expander balloon, wherein the containment assembly limits a degree of distension of the expander balloon, and the fiber patterns of the containment assembly are exposed. Such a prostatic tissue expander can further include additional reinforcements and cuffs. The method for positioning a prostatic tissue expander can be used in a method for treating benign prostatic hypertrophy.

Description

PROSTATIC TISSUE EXPANSION

TECHNICAL FIELD The present invention relates to medical tissue expansion. In particular, this invention relates to devices and methods for expanding the urethra and the surrounding prostatic tissue.

BACKGROUND The prostate gland encircles the male urethra at a point near the bladder. A common problem in men over fifty years old is the enlargement of the prostate gland, which can constrict the flow of urine through the urethra, causing numerous uncomfortable symptoms. Excessive prostate enlargement is referred to as benign prostate hypertrophy (BPH). There are both surgical and nonsurgical treatments available for treating BPH.

One surgical solution is transurethral resection of the prostate (TURP), which is one of the most common surgeries confronting adult males today. TURP is carried out by a physician who inserts a narrow tube-like instrument called a resectoscope into the penis. Once the resectoscope is inside the penis, the physician carves out a portion of the prostate thereby enlarging the urinary passageway.

An alternative to TURP surgery is the use of a small balloon that is temporarily inserted into the urinary canal. The deflated balloon is positioned within the urethra at the point where the urethra passes through the prostate and then inflated to enlarge the urinary passageway. This procedure is not unlike angioplasty procedures used to enlarge clogged blood vessels. In the case of the prostate, however, the procedure is known as transcystoscopic urethroplasty (TCU). Typically, TCU is performed over a relatively short period of time, usually minutes. Further, it is generally thought that the larger the initial dilation, the better. Consequently, balloon dilation of the prostatic urethra may produce a commissurotomy or tearing, which is considered by some to enhance the results. Bleeding frequently accompanies the procedure. Under certain circumstances, a catheter may be placed within the urethra immediately following the dilation to allow the patient to void comfortably. Unfortunately, it has been found that the benefits associated with TCU are fairly short lived. Due to the notable drawbacks associated with undergoing surgery and the short lived benefits associated with TCU, there exists a need for improved treatment alternatives for BPH.

SUMMARY In one aspect, the present invention is directed to a device and method for prostatic tissue expansion. In one embodiment, a prostatic tissue expander can contain a urethral catheter, a positioning balloon disposed about the catheter, an expander balloon disposed about the catheter, and a containment assembly disposed about the expander balloon wherein the containment assembly may limit a degree of distension of the expander balloon, and wherein the containment assembly can include a plurality of yarns, at least some of the yarns of the containment assembly being exposed. Useful yarns can include can include any fiber and/or filament that can function as a knittable yarn.

In one embodiment, the containment assembly is distensible and can be knitted. The knitted containment assembly can be knitted in a jersey stitch fashion out of at least one distensible yarn component and at least one substantially non- distensible yarn component. The distensible yarn can include spandex. The substantially non-distensible yarn can include nylon, polypropylene, polyester, polyethylene and aramids. For example, the distensible yarn can be spandex and the substantially non-distensible yarn can be polyethylene, such as an ultra high molecular weight polyethylene. The containment assembly can have an exposed outer surface for contact with an interior wall of a urethral channel of a patient and the outer surface can be structured to facilitate secure positioning of the expander balloon within a urethra of a patient. The containment assembly can further include a woven component.

The containment assembly can be effective for producing a uniform axial expansion of the expander balloon along a longitudinal axis of the expander balloon. The containment assembly can also be effective for returning the expander balloon from an inflated condition to an uninflated condition when an inflation solution is removed from the expander balloon.

In another embodiment, the prostatic tissue expander can include a reinforcement material. The reinforcement material can be circumferentially wrapped about an end of the containment assembly to hold a portion of the containment assembly about the expander balloon. The reinforcement can be nondistensible and can be a fiberglass fiber. The reinforcement material can provide reinforcement in the hoop direction. In another aspect, the expander balloon of the prostatic tissue expander can include an adhesion collar having at least one adhesive pocket for receipt of an adhesive that bonds the expander balloon to the catheter. Additionally, the positioning balloon can include an adhesion collar that has at least one adhesive pocket for receipt of an adhesive that bonds the positioning balloon to the catheter. The adhesion collar can include at least one annular projection that comprises a radiused surface for contacting an outer surface of the urethral catheter. The adhesive pocket can include at least one radiused corner.

In another embodiment, the prostatic tissue expander can include a urine port, a first lumen for inflation and deflation of the positioning balloon, a second lumen for inflation and deflation of the expander balloon, and a third lumen for fluid communication with the urine port to discharge urine from the catheter.

In another embodiment, the containment assembly of the prostatic tissue expander can have a first end disposed within a first cuff and a second end disposed within a second cuff, the first and second cuffs holding opposite ends of the containment assembly about the catheter. The containment assembly within the cuffs can be stretched and/or impregnated with an elastomeric matrix. The containment assembly within the cuffs can be stretched longitudinally.

In another embodiment, the containment assembly of the prostatic tissue expander can have a first end disposed within a first cuff and a second end disposed within a second cuff, the first and second cuffs holding opposite ends of the expander balloon about the catheter. The containment assembly within the cuffs can be stretched and/or impregnated with an elastomeric matrix. The containment assembly within the cuffs can be stretched longitudinally.

In still another embodiment, the prostatic tissue expander can include a reinforcement material with the balloon cuffs and/or the containment assembly cuffs being reinforced with the reinforcement material. The reinforcement material can include a fiberglass fiber, which can be circumferentially wrapped about the exterior surface of the cuffs. The reinforcement material can provide reinforcement in the hoop direction.

In another embodiment, the present invention provides a method for securing a prostatic tissue expander by inserting a prostatic tissue expander into a urethra of a patient, inflating the positioning balloon in a bladder of the patient so as to position the expander balloon within a portion of the urethra coincident a prostate of the patient, partially inflating the expander balloon so as to secure the prostatic tissue expander within the urethra of the patient, and deflating the positioning balloon. In one aspect, the prostatic tissue expander includes a catheter, a positioning balloon disposed about the catheter, and an expander balloon disposed about the catheter. In another embodiment, the method for securing a prostatic tissue expander can further include inflating the expander balloon to a desired inflation size following the deflation of the positioning balloon. The positioning balloon and the expander balloon can be inflated with an isotonic solution.

In another embodiment, the present invention includes a method for treating benign prostatic hypertrophy by inserting a prostatic tissue expander into a urethra of a patient, inflating the positioning balloon in a bladder of the patient so as to position the expander balloon within a portion of the urethra coincident with a prostate of the patient, partially inflating the expander balloon so as to secure the prostatic tissue expander within the urethra of the patient, and deflating the positioning balloon. In another aspect, the prostatic tissue expander can include a catheter, a positioning balloon disposed about the catheter, and an expander balloon disposed about the catheter. In another embodiment, the method for treating benign prostatic hypertrophy can further include more fully inflating the expander balloon after deflating the positioning balloon. In an additional aspect, the expander balloon can be inflated incrementally. The positioning balloon and the expander balloon can be inflated with an isotonic solution.

In another aspect, the prostatic tissue expanders and methods for using the prostatic tissue expanders include securing the prostatic tissue expander in a patient for less than about 7 days, less than about 30 days, for greater than about 30 days and less than about 60 days. Additionally, the expander balloons can be incrementally inflated over a period of hours, days or months. For example, the expander balloon can be incrementally inflated over a period of days less than about 30 days, over a period of days greater than about 30 days and less than about 60 days. In another embodiment, the prostatic tissue expanders and methods for using the prostatic tissue expanders include inflating the expander balloon of the prostatic tissue expander for a first time to at least about 75% of a maximum diameter of the expander balloon and inflating the expander balloon a second time to a diameter greater than the first time. The expander balloon can also be incrementally inflated for a first time less than about 75%> of a maximum diameter of the expander balloon, and inflating the expander balloon a second time to a diameter greater than the first time.

In another aspect, the expander balloons of the prostatic tissue expanders disclosed herein, including the prostatic tissue expanders used in the methods disclosed herein, can expand to at least about 100 French, 120 French, or at least about 150 French.

In still another embodiment, a method for manufacturing a containment assembly of a prostatic tissue expander can include the steps of: stretching a containment assembly along its longitudinal axis, contacting the stretched containment assembly with an adhesive at specified intervals, and allowing the adhesive to cure. In one aspect, the containment assembly is stretched over a rod, which can have an external diameter less than the external diameter of the prostatic tissue expander in the region of a balloon. The containment assembly can be stretched to about its maximum longitudinal length. The specified intervals can be cuff areas. The stretching can take place at the intervals including the cuffs.

In another aspect, an expander balloon for use in a prostatic tissue expander can contain an elastomeric balloon and at least one adhesion collar. The adhesion collar can include at least one adhesive pocket for receipt of an adhesive that bonds the expander balloon to a urethral catheter shaft. The adhesion pocket can include at least one minor diameter and at least one major diameter, the minor diameter being sized smaller than an outer diameter of the urethral catheter shaft. Further, the adhesive pocket can contain at least one radiused corner. The adhesive pocket can include at least one annular projection containing at least one radiused corner, the radiused corner being disposed on a portion of the annular projection adjacent to a surface of the adhesive pocket that defines the major diameter. In another embodiment, a second corner of the annular projection is disposed adjacent to a surface of the annular projection contacting the urethral catheter shaft, the second corner being substantially square.

In another embodiment, the present invention provides an article of manufacture containing a packaging material and a prostatic tissue expander contained within the packaging material, the packaging material further containing a label or package insert indicating that inserting a prostatic tissue expander within a urethra of a patient, inflating a positioning balloon so as to properly position an expander balloon within a portion of the urethra being within a prostate of the patient, inflating the expander balloon so as to secure the prostatic tissue expander within the urethra of the patient, and deflating the positioning balloon can be effective for treating a patient suffering from benign prostate hypertrophy.

Other advantages, features, and embodiments of the present invention will become apparent from the following detailed description and claims.

DESCRIPTION OF DRAWINGS FIG. 1 is a side-view of a prostatic tissue expander with a positioning balloon and an expander balloon in an inflated condition;

FIG. 2 is a cross-sectional view of a lumen of the prostatic tissue expander along line 1-1 of FIG. 1.

FIG. 3 is a longitudinal cross-sectional view of a balloon region of the prostatic tissue expander depicted in FIG. 1 with the positioning balloon and the expander balloon in an uninflated condition; FIG. 4 is a longitudinal cross-sectional view of a single contiguous balloon assembly that can be assembled onto a urethral catheter to form a positioning balloon and an expander balloon that can be used to construct a prostatic tissue expander as depicted in FIG. 1 ; FIG. 5 is a cross-sectional view of the single molding containing two balloons of FIG. 4 taken along line 2-2;

FIG. 6 is a cross-sectional view of the single molding containing two balloons of FIG. 4 taken along line 3-3;

FIG. 7 is an enlarged cross-sectional view of the single molding containing two balloons of FIG. 4;

FIG. 8 is an enlarged cross-sectional view of the prostatic tissue expander of FIG. 3;

FIG. 9 shows an example of a jersey stitched tube that can be fabricated into a containment assembly for use in a prostatic tissue expander incorporating aspects of the invention;

FIG. 10 is a longitudinal side-view of multiple containment assemblies disposed about a manufacturing rod during fabrication of the containment assemblies; FIG. 11 is a perspective view of a single containment assembly including cuffs impregnated with a cured matrix material; FIG. 12 is a conceptual side view of a containment assembly installation tool; and

FIG. 13 is a side-view of a prostatic tissue expander following insertion into the male urethra and at a point during the positioning of the prostatic tissue expander. Like reference numbers and designations in the various drawings indicate like elements.

DETAILED DESCRIPTION FIG. 1 is a side view of an inflated prostatic tissue expander device 2 (PTE 2). Briefly, PTE 2 along its longitudinal axis 4, proceeding from a distal end 6 to a proximal end 8, includes a distal tip 10, a catheter shaft 12, a urine port 14, a positioning balloon 16, an expander balloon 18, a containment assembly (not shown in FIG. 1) that surrounds the expander balloon 18, and a catheter triple funnel assembly 20. Catheter shaft 12 and the catheter triple funnel assembly 20 may define three lumens 22, 24, 26 that can be common to a positioning balloon lumen 28, an expander balloon lumen 30, and the urine port 14, respectively. Lumens 22, 24 can facilitate inflation and/or deflation of their respective balloon. Lumen 26 can provide fluid communication with a bladder through urine port 14 to facilitate urine discharge. Examples of additional embodiments and features that can be incorporated into PTE 2 are disclosed in United States patent application 08/791,514, the entire content of which is incorporated herein by reference. Preferably, the PTE 2 is configured and sized for insertion into the male urethra. Dimensions for urethral catheters, including Foley-type urethral catheters in general, can be obtained from British Standard (BS) 1965 Part 1 or American Society for Testing & Materials F-623.

FIG. 2 is a cross-sectional view along line 1-1 of FIG. 1, showing the tri- lumen aspects of catheter shaft 12. As shown in FIG. 2, catheter shaft 12 may include an outer surface 32 and a catheter wall 34 that defines lumens 22, 24 for communication with balloon lumens 16, 18, respectively, and the lumen 26 for communication with the bladder. Catheter shaft 12 can be formed from any flexible, biocompatible material. One suitable material for fabricating catheter shaft 12 is the elastomeric silicone sold under the trade designation HCRA 80E, which is available from Applied Silicones, 320 West Stanley Ave., Ventura, CA 93001.

FIG. 3 shows a cross-sectional view along longitudinal axis 4 of distal end 6 of PTE 2 depicting a region of PTE 2 in which balloons 16, 18, are disposed. In FIG. 3, positioning balloon 16 and expander balloon 18 are shown in a deflated condition. As indicated above, catheter shaft 12, including distal tip 10, can be formed from any acceptable biocompatible material that results in a catheter that is flexible enough to follow bends in the urethra upon insertion of PTE 2. Preferably, the catheter is rigid enough to allow the PTE 2 to pass any obstructions within the patient's urethra. Examples of suitable biocompatible materials for constructing catheter shaft 12 and distal tip 10 include silicone, latex, polyvinyl chloride and polyurethane.

Distal tip 10 is typically radiused at its distal end 6 to facilitate insertion of the PTE 2 into the urethra. The PTE 2 can also be curved at the distal end 6 (not shown). Distal tip 10 may be formed integrally with the remainder of catheter shaft 12 or mounted as a discrete component at distal end 6. For example, distal tip 10 can be attached to catheter shaft 12 using an elastomeric adhesive 36. Elastomeric adhesives are known and include room temperature vulcanized adhesives (described below). The elastomeric adhesive 36 can be a silicone adhesive when the distal tip 10 and the catheter shaft 12 are also silicone. In either case, distal tip 10 will be described as a discrete portion of catheter shaft 12. A diameter of distal tip 10 along its longitudinal axis 4 can be from about 12 French (1 mm = 3 French) to about 30 French, preferably from about 12 French to about 18 French. Urine port 14 can be round, circular or oval in shape and should not exceed the width of the lumen 26. A urine port 14 that is wider than the width of lumen 26 may weaken the catheter shaft 12 without increasing the area of the urine port 14.

As depicted in FIG. 3, positioning balloon 16 can be of a one-piece tubular construction and can be disposed radially about catheter shaft 12. Positioning balloon 16 can include a first adhesion collar region 38, 39 that is generally indicated by that part of the positioning balloon 16 located between reference numerals 38 and 39 and a second adhesion collar region 40, 41 that is generally indicated by that part of the positioning balloon 16 located between reference numerals 40 and 41. Adhesion collar regions 38, 39 and 40, 41 can be used to secure the positioning balloon 16 to the outer surface 32 of catheter shaft 12. The distance between the distal end 6 of distal tip 10 to reference numeral 38 is preferably from about 30 mm to about 40 mm. Positioning balloon 16 is typically a Foley type balloon and can be formed from a low modulus elastomeric material such as latex, silicone, C-flex, or other distensible elastomer. C-flex is a trade designation for a styrene ethylene butylene styrene modified block polymer and is available from Concept Polymer Technology, 12755 60th St, Clearwater, FL 34620. Positioning balloon 16 may be constructed from multiple layers. To inflate positioning balloon 16, an inflation syringe (not shown) may be used to force from about 5 ml to about 30 ml of an inflation liquid along lumen 22 through an eyelet 44 so as to change the positioning balloon 16 from a deflated condition as depicted in FIG. 3 to an inflated condition as depicted in FIG. 1. The positioning balloon 16 and the lumen 22 can be constructed so that in an inflated condition positioning balloon lumen 28 (FIG. 1) together with lumen 22 hold from about 5 ml to about 10 ml of fluid. The positioning balloon 16 should have a generally symmetrical annular shape and should not block urine port 14 when inflated. In its uninflated condition, the length of the positioning balloon 16 along its longitudinal axis 4 can be from about 1 cm to about 2 cm in length, preferably 1.5 cm. When in a deflated condition, the positioning balloon 16 can add from about 1 French to about 6 French to the axial diameter of the catheter shaft 12, preferably 2 French.

In FIG. 3, the positioning balloon 16 and the expander balloon 18 are fabricated as a single molding containing two balloons (described below). As a consequence, the second adhesion collar 40, 41 is common to both the positioning balloon 16 and the expander balloon 18. Thus, even though second adhesion collar 40, 41 is described as containing that portion of the positioning balloon 16 that is disposed between reference numerals 40 and 41 , it can also be referred to as that portion of the expander balloon 18 that is disposed between reference numerals 40 and 41. Second adhesion collar 40, 41 can function to separate different sections of the single molding containing two balloons to produce the positioning balloon 16 and the expander balloon 18 at different axial regions of catheter shaft 12. Alternatively, the positioning balloon 16 and the expander balloon 18 can be constructed as separate balloons. When constructed as separate balloons, the positioning balloon 16 and the expander balloon 18 could each have a separate adhesion collar disposed in the area generally indicated by reference numerals 40, 41. These adhesion collars could be disposed adjacent to each other or disposed in an overlapping fashion. Disposing the interposed adhesion collars in an overlapping configuration will likely increase the overall diameter of the adhesion collar region, which should generally be avoided. Fabricating the positioning balloon 16 and expander balloon 18 separately can be advantageous if, for example, different materials are used to construct the balloons 16, 18, if one of the balloons is colored, or if one of the balloons radiopaque. Expander balloon 18 can be of a one-piece tubular construction and can be disposed radially about catheter shaft 12. The expander balloon 18 can include the second adhesion collar region 40, 41 that is generally indicated by that part of the positioning balloon 16 located between reference numerals 40 and 41. The expander balloon 18 can include a third adhesion collar 46, 47 that is generally indicated by that part of the expander balloon 18 located between reference numerals 46 and 47. Adhesion collar regions 40, 41 and 46, 47 can be used to secure the expander balloon 18 to the outer surface 32 of catheter shaft 12. Expander balloon 18 is typically a distensible balloon and can be formed from a low modulus elastomeric material such as latex, silicone, C-flex, or other suitable distensible elastomer. Expander balloon 18 may also be of a multiple layer construction.

To inflate expander balloon 18, an inflation syringe (not shown) may be used to force an inflation liquid along lumen 24 through eyelet 50 so as to change the expander balloon 18 from a deflated condition as depicted in FIG. 3 to an inflated condition as depicted in FIG. 1. The expander balloon 18 can also be fabricated to produce various inflated lengths. Typically, the expander balloon 18 lengths are from about 15 mm to about 75 mm. The length of the expander balloon 18, however, can vary according to the length of the patient's prostatic urethra. The expander balloon can be constructed so that the inflated condition can vary in diameter. Inflated diameters for expander balloons can range, for example, from about 30 French to about 150 French. For example, a PTE 2 in accordance with an embodiment of the invention may inflate to a final diameter of at least about 30 French, 40 French, 50 French, 60 French, 70 French, 80 French, 90 French, 100 French, 110 French, 120 French, 130 French, 140 French, or 150 French. The positioning balloon 16 and the expander balloon 18 (referred to collectively as balloons 16, 18) can be bonded or suitably secured to the catheter outer surface 32 using any biocompatible adhesive that will adhere to both catheter outer surface 32 and balloons 16, 18 using known bonding techniques. For example, a room temperature vulcanized (RTV) silicone adhesive can be used. Useful RTV silicone adhesives include the adhesive sold under the trade designation SWS 951 by Wacker Silicone Corporation, 3301 Sutton Rd., Adrian, MI 49221. Adhesion collar region 40, 41 can be constructed so as to place a distance from about 0.5 cm to about 1.0 cm between a proximal end 52 of positioning balloon 16 and a distal end 54 of expander balloon 18. It may be advantageous, however, to place distances greater than about 1.0 cm between the proximal end 52 of positioning balloon 16 and the distal end 54 of expander balloon 18. The distance is to be computed when both balloons 16, 18 are in a deflated condition. It is to be understood that the distance can vary according to the size of the PTE 2 and the size of the balloons 16, 18 that are used. The distance can be optimized so as to minimize the pressure placed on a patient's bladder neck when the balloons 16, 18 are in an inflated condition.

Methods for fabricating distensible balloons are known and will not be described in detail. The positioning balloon 16 and the expander balloon 18 can be molded as a single molding containing two balloons or as separate balloons using a 20 shore A durometer platinum cured silicone elastomer or other suitable elastomer. A useful elastomer for constructing balloons 16, 18 can contain a mixture of silicone elastomers. For example, silicone elastomers sold by Applied Silicones under the trade designation HCRA 20M and HCRA 20 with 20038 cross linker can be combined in a 1 part HCRA 20M to 9 parts HCRA 20 with 20038 cross linker ratio and then molded into a balloon 16, a balloon 18, or a single molding containing two balloons.

FIG. 4 shows a cross-sectional view along axis 4 of a single balloon molding 56 containing two balloons prior to being disposed about the catheter shaft 12 (not shown). The balloon assembly 56 can be generally annular in shape. When assembled into a PTE 2, the balloon molding 56 can include the positioning balloon 16, the expander balloon 18, the first adhesion collar 38, 39, the second adhesion collar 40, 41 and the third adhesion collar 46, 47 as is depicted in FIG. 3. FIG. 4 indicates the general location of the positioning balloon 16, the expander balloon 18, the first adhesion collar 38, 39, the second adhesion collar 40, 41 and the third adhesion collar 46, 47 in an assembled PTE 2 (not shown). The balloon molding 56 can have walls whose wall thickness varies along the longitudinal length of the balloon molding 56. For example, balloon molding 56 can have one or more walls 58, 60, 62 whose thickness is less than walls 64, 66. Manufacturing walls 58, 60, 62 that are thinner than walls 64, 66 can help minimize the overall thickness of the PTE 2 (not shown) in adhesion collar regions of the PTE 2.

The balloon molding 56 can have one or more annular projections 68 (indicated in FIG. 4 by reference numerals 68_a-0) disposed axially along the length of the balloon molding 56. FIG. 5 shows a cross section along line 2-2 of FIG. 4 adjacent to an annular projection 68, in this instance annular projection 68_m. Each annular projection 68 can be defined by a major diameter 70 and a minor diameter 72. Sizing the minor diameter 72 smaller than an outer diameter of the catheter shaft 12 (not shown) can protect against adhesive migration during assembly of the balloon molding 56 to the catheter shaft 12 (detailed below). The balloon molding 56 also has an outer diameter 74. It is to be understood that each annular projection 68 can have a major diameter 70 and minor diameter 72 that is unique to that annular projection. Returning to FIG. 4, the balloon molding 56 can have one or more annular projections 76 (a representative sample of the annular projections indicated by reference numerals 76_a__d) disposed axially along the length of the balloon molding 56. FIG. 6 shows a cross section view along line 3-3 of FIG. 4 of an annular projection 68, in this instance annular projection 76_c. Each annular projection 76 can be defined by a major diameter 78 and a minor diameter 80. When assembled into a PTE 2, the annular projections are preferably in a region of the PTE 2 that corresponds to the positioning balloon 16 and/or the expander balloon 18. Sizing the minor diameter 80 smaller than an outer diameter of the catheter shaft 12 (not shown) can provide a tight fit of the balloons 16, 18 against the catheter shaft 12 and can predispose the balloons 16, 18 to return to the tight fit when the balloons 16, 18 are deflated. The annular projections 76 can function to minimize the contact area between the catheter outer surface 32 and the balloons 16, 18 and can keep the positioning balloon 16 or the expander balloon 18 from sticking to the outer catheter surface 32 (not shown) when the positioning balloon 16 and/or the expander balloon 18 are in a deflated condition. Inflating a positioning balloon 16 or an expander balloon 18 that is a sticking or adhering to the outer catheter surface 32 can cause premature failure of the balloons 16, 18 or nonuniform expansion of the balloons 16, 18. The balloon molding 56 also has an outer diameter 82. FIG. 7 shows an enlarged cross-sectional view of a transition region 84, annular projections 68, and annular projections 76 of the balloon molding 56 shown in

FIG. 4. As indicated in FIG. 4, the PTE 2 can have multiple transition regions 83, 84,

85, 87. The balloon molding 56 can be molded so that the minor diameter 72 (shown in FIG. 5) of the annular projections 68 shown in FIG. 4 is defined by an annular surface 86. As depicted in FIG. 7 surface 86 can be radiused. The surface 86 can also be manufactured flat so as to maximize the contact area between the surface 86 and the catheter outer surface 32 (not shown). The surface 86 can contact the catheter outer surface 32 when the balloon molding 56 is installed. The major diameter 70 (shown in FIG. 5) of the balloon molding 56 can be defined by an annular surface 88. An annular wall surface 90 can connect the surface 88 and the surface 86. The wall surface 90 can be straight or tapered. Preferably, the annular surface 88 has radiused comers 92, 93. The surface 86 can be substantially flat so as to maximize contact with the catheter outer surface 32 (not shown). Fabricating comers 94 that are square as opposed to radiused may increase the surface area of the surface 86 that is in contact with the catheter outer surface 32. Typically, machining corners 94 as rounded comers is technically easier.

The balloon molding 56 can include annular surfaces that have nonidentical comers. For example, annular surface 96, which is adjacent to annular projection 68_e and annular projection 76_a, has a comer 98 similar to the radiused comers 92, 93 and a co er 100 that is defined by annular projection 76_a.

Balloon molding 56 can be disposed about the catheter outer surface 32 and suitably secured thereto to form the positioning balloon 16 and the expander balloon 18 as depicted in FIG. 3. Care should be taken to ensure that the balloon covers both eyelets 44, 50 during assembly. FIG. 8 shows an enlarged cross-sectional view of the PTE 2 of FIG. 3 in the region of adhesion collar 40, 41 of the balloon molding 56. The balloon molding 56 can be secured to the catheter outer surface 32 by filling adhesive pockets 102, 103, 104, 105 with a suitable adhesive (i.e, crosshatching of the adhesive pockets). The adhesive pockets 102, 103, 104, 105 can be formed when annular projections 68_f, 68_g, 68_n, 68j, 68_j contact the catheter outer surface 32.

Adhesive can be applied by positioning adhesive dispensing equipment coupled to blunt needles within the adhesive pockets 102, 103, 104, 105 and then dispensing adhesive into the pockets. Useful pneumatic syringe and needle adhesive dispensing equipment can be obtained fromEFD International, Inc., 977 Waterman Ave., East Providence, RI 02914. The techniques used to secure the balloon molding 56 in the adhesion collar region 40, 41 can also be used to secure adhesion collars 38, 39 and 46, 47 of the balloon molding 56 shown in FIG. 4.

Adhesive pockets of adhesion collars (38, 39), (40, 41) and (46, 47) can be accessed with the syringe and needle adhesive dispensing equipment from the side by sliding the needle along the catheter outer surface 32 and under the annular projections 68. Accessing adhesive pockets 102, 103, 104, 105 from the side can increase the chance of adhesive being deposited within the expander balloon 18 or the positioning balloon 16. A preferred method for securing adhesion collar 40, 41 to the catheter outer surface 32 includes piercing the adhesion collar 40, 41 in the regions corresponding to the adhesive pockets 102, 103, 104, 105 with the blunt needle or other suitable instrument to gain access to the adhesive pockets 102, 103, 104, 105. Adhesive can then be deposited throughout each adhesive pockets 102, 103, 104, 105. After dispensing the adhesive, the needle can be withdrawn from the adhesion collar 40, 41 allowing the adhesive to seal the hole created by piercing the adhesion collar 40, 41.

Preferably, the expander balloon 18 is of a limited distensibility. Limited distensibility can be achieved by fabricating the expander balloon 18 from a high modulus elastomer such as polyurethane. Alternatively, expander balloon 18 can be fabricated from a lower modulus elastomer and covered with an exposed containment assembly 110, as shown in FIG. 3 and in FIG. 8. An exposed containment assembly 110 would not be imbedded in an elastomer or other substance.

An exposed containment assembly 110 can be fabricated as a knit, i.e., containing an interlocking stitch, using any method. A knit exposed containment assembly 110 can be fabricated using any fiber or filament that can function as a knittable yam. A containment assembly 110 fabricated as a knit would be considered exposed when the yams that are used to fabricate the containment assembly 110 are at least partially exposed such that the yams could be in direct contact with a patient's urethra. The containment assembly 110 can be fabricated as a knit tube or as one or more flat knits that can be connected to each other, or connected to itself if only one knit is used, forming an enclosed structure not unlike a tube. Knitting techniques for fabricating knit tubes and flat knits are known. Knit tubes can be fabricated on circular or flat bed knitting machines. Useful knit patterns include any jersey stitch pattern, e.g., single knit, double knit, and stocking stitch, and knit patterns that further contain an interlaced yam(s), i.e., a woven component. Useful woven components can include distensible ya s, nondistemsible yam, and/or radiopaque yams. FIG. 9 shows a single jersey stitch knit 112 that can be fabricated into a containment assembly 110. FIG. 9 also includes an expanded view of a jersey stitch pattern 114 of the single jersey stitch knit 112.

The containment assembly 110 can be fabricated from a knit manufactured using a distensible yam and a non-distensible yam. The containment assembly 110 can provide resistance to the expander balloon 18 as it is inflated and can facilitate the expander balloon expanding in a uniform diameter along the longitudinal axis of the expander balloon 18. Useful distensible fibers that can function as yarns include distensible polyurethane polymer yams such as spandex. Useful non-distensible fibers that can function as yams include nylon, polypropylene, polyester, polyethylene, and aramid yams. A useful example of an aramid yam is the yam sold under the trade name KEVLAR (TM). Preferred nondistensible yams include ultra high molecular weight polyethylene (UHMWPE) yams because UHMWPE yams provide high tensile strength having tenacities of 30 grams/denier. UHMWPE yams have a relatively low coefficient of friction and are less abrasive to itself and other yams that can be included in the containment assembly 110. UHMWPE yams are also biocompatible, which is important because in a knit exposed containment assembly 110, the yam fibers would be in contact with the patient's urethra. The containment assembly 110 can be sized so as to allow the expander balloon to expand from about 15. French to about 150 French. The length and width of the containment covering 110 can affect the largest diameter that the expander balloon 18 can achieve in an expanded condition. Sizing of a containment assembly 110 fabricated from a knit can be achieved by varying the number of needles used to knit the assembly 110. Useful containment assemblies 110 can be knit using from about 15 needles to about 50 needles. Typically, a 20 needle setting will allow for a containment assembly 110 that can expand up to about 65 French. A 34 needle setting can be used to achieve containment coverings 110 that may achieve diameters from about 85 French to about 115 French. A preferred containment assembly 1 10 is a 34 needle jersey stitch knitted on a flat bed knitting machine from a distensible spandex and a non-distensible polyethylene yams, e.g., a jersey stitch knitted using the spandex sold under the trade designation Lycra 146C/140D by E.I. DuPont de Nemours & Co., Inc., Textile Fibers Dep , Wilmington, De. 19898, and the polyethylene yam sold under the trade designation Spectra 50D by Allied Signal Fibers, 1411 Broadway, New York, NY 10018. As indicated above, a containment assembly 110 can remain as an exposed knit. In this manner, containment assembly 110 can positionally secure the PTE 2 within the prostatic urethra, as described in detail below. PTEs 2 that have a relatively small diameter when the balloons 16, 18 are in an uninflated condition are generally easier to insert into the urethra. Constructing the PTE 2 so that the balloons return to a relatively small diameter after being in an inflated conditions can facilitate easier removal of the PTE 2 after use. Constructing a two yam containment assembly 110 out of Spandex and UHMWPE yarns can provide a containment assembly 110 that has minimal bulk when the balloons 16, 18 are in a uninflated condition. Containment assemblies 110 fabricated out of Spandex and UHMWPE yams can also promote recovery of the balloons 16, 18 from an inflated condition to an uninflated condition when the inflation liquid is removed. The two yam containment assembly can provide enough reinforcement to allow expander balloons to approach 150 French in an inflated condition. The high tensile strength, resistance to abrasion, and low coefficient of friction associated with UHMWPE yams can facilitate useful containment assemblies 110 manufactured using two yam knits. The characteristics associated with UHMWPE can facilitate fabricating knit containment assemblies 110 that can be used in an exposed condition without leading to balloon failure or excessive urethra discomfort.

Referring to FIG. 3 and to FIG. 8, containment assembly 110 can be disposed about expander balloon 18 and suitably secured to an outer surface 116 of the expander balloon 18 by applying an adhesive 118 (not indicated in FIG. 3) such as an RTV silicone adhesive. Adhesive 118 can be applied along the expander balloon 18 between reference numerals 40 and 41 and between reference numerals 46 and 47.

The containment assembly 110 may further encompass cuffs 120, 122 that are regions of the containment assembly 110 that can be pre-stretched in the longitudinal direction and pre-impregnated with an elastomeric matrix prior to installing the containment assembly 110. In such an embodiment, the cuffs 120, 122 will be cut to a length about equal to the length of the adhesion collar 40, 41 and adhesion collar 46, 47, respectively, prior to installing the containment assembly 110. Pre-stretching and pre-impregnating cuffs 120, 122 can be advantageous because less fraying and unraveling of the ends of the containment assembly 110 occurs when the containment assembly is radially expanded prior to disposing the containment assembly 110 about the expander balloon 18. Longitudinal pre-stretching can also reduce the diameter of the cuffs 120, 122 during impregnation with an elastomeric matrix. Additionally, pre- stretching reduces the overall cuffs 120, 122 thickness, which facilitates minimizing the overall diameter of the PTE 2 when the balloons 16, 18 are in a deflated condition. Pre-stretching can also facilitate a more uniform impregnation of the containment assembly 110 fibers, which can result in better adhesive characteristics when the containment assembly 110 is disposed about the expander balloon 18. An expander balloon 18 that expands to a diameter approaching 100 French and beyond can impose excessive peel stresses where the balloon 18 is attached to the catheter outer surface 32 causing the expander balloon 18 and perhaps even positioning balloon 16 to fail. As such, it may be necessary to reinforce the expander balloon 18 with a secondary reinforcement material. Referring again to FIG. 3 and FIG. 8, the secondary reinforcement can include a nondistensible fiber or yarn 124, 126 that can be circumferentially wrapped about cuffs 120, 122 and bonded thereto. For example, a silicone impregnated fiberglass yam, such as the yarn sold under the trade name ECD225 1/0 with 636 sizing by Owens Coming Fiberglas Co., Fiberglas Tower, Toledo, OH 43659, can be imbedded in an RTV silicone adhesive matrix as described above. The impregnated fiberglass yam can be wound about cuffs 120, 122 and allowed to cure. The wrapping technique can be advantageous because it reinforces the underlying expander balloon 18 and cuffs 120, 122 with a high tensile reinforcement oriented in the hoop direction, i.e., radial reinforcement, while remaining somewhat flexible. Other materials that may provide adequate reinforcement include polyester yams, DACRON (TM) and KEVLAR (TM).

An over coating 128 (labeled in FIG. 8) of a silicone adhesive such as the adhesive sold under the trade designation GE 118 and available from FE Silicones, 260 Hudson River Road, Waterford, NY 12188, can be applied to secondary reinforcement yams 124, 126 and/or directly to cuffs 120, 122 to provide a smooth surface. Referring to FIG. 3 and to FIG. 8, the coating 128 can be used to create smooth transitions 130, 132, 134 between regions of disparate diameters along the PTE 2. Minimizing abrupt changes in diameter can facilitate insertion and removal of the PTE 2 and minimize patient discomfort.

The containment assembly 110 further encompassing pre-stretched/pre- impregnated cuffs 120, 122 can be fabricated using the following illustrative method. In FIG. 10, a piece of jersey stitch knit tube 112 can be stretched along a rod 136 along the longitudinal axis 4. Typically, the rod 136 is coated with a polytetrafluoroethylene fluorocarbon polymer such as TEFLON (TM). Preferably, the jersey stitch knit tube 112 is stretched to its maximum longitudinal length. The rod 136 can be similar in shape to the catheter shaft 12 (not shown) and can be of a smaller diameter. For example, the diameter of the rod 136 can be approximately 5/32 inch in diameter (0.156 inch) when the outside diameter of the cuffs 120, 122, after being installed about the expander balloon 18, is about 0.225 inch. Clamps 138, 140 can be used to secure an end 142, 144 of the jersey stitch knit tube 112 to the rod 136. An RTV silicone adhesive such as the Wacker silicone adhesive SWS 951 can be dispensed along the jersey stitch knit tube 112 at intervals 146, 147, 148, 149 corresponding to the location of cuffs 120, 122 in a finished containment assembly 110. The rod 136 can be rotated about its longitudinal axis 4 as the adhesive is applied and until the adhesive has hardened to a point such that the adhesive will not sag. The adhesive can be allowed to volatilize and cure for at least about 12 hours before removing the rod 136. Preferably, the adhesive is thinned to reduce its viscosity by mixing it with an appropriate amount of a suitable solvent such as xylene. Thinning the adhesive can help to minimize the final thicknesses of cuffs 120, 122. Further, thinning can enhance the wetting of the individual reinforcement yams.

It is to be understood that the jersey stitch knit tube 112 can be processed on a single rod so as to produce multiple containment assemblies 110. For example, FIG. 10 shows a jersey stitch knit tube 112 with adhesive applied to four intervals 146, 147, 148, 149. After the adhesive has cured, the jersey stitch knit tube can be removed from the rod 136 and cut at points 152, 153, 154, and 155 so as to produce three containment assemblies 110. Accordingly, a longer rod could be used to fabricate more containment assemblies 110 per rod. As depicted in FIG. 10, the adhesive should be applied to an area that is at least as long as two individual cuff lengths (intervals 153, 154), e.g., a length at least as long as the combined length of cuff 120 and cuff 122, when fabricating multiple containment assemblies 110.

Applying the adhesive to a length of the jersey stitch knit 112 that is greater than the final length of cuffs 120, 122 length provides room to trim the cuffs to size. Typically, final cuffs 120, 122 lengths are from about 0.2 inches to about 0.4 inches. FIG. 11 shows a perspective view of a pre-stretched and pre-impregnated containment assembly 110 that can be fabricated using the above described method. The containment assembly 110 includes the pre-stretched and pre-impregnated cuffs 120, 122 and an un-stretched and non-impregnated jersey stitch knit portion 158. At this point, the containment assembly 110 can be disposed about the expander balloon 18 (not shown). Notably, the cured adhesive prevents the full longitudinal relaxation of the containment assembly material in the cuffs 120, 122 region, which results in a thinner cuff. The relaxed cuff 120, 122 may be distorted due to the forces imparted by the pre-stretched cuff material. This distortion can be eliminated or minimized when the containment assembly 110 is disposed about the expander balloon 18. FIG. 12 is a conceptual diagram that depicts a cross-sectional view of a reinforcement stretching tool 160 that can be used for installing the containment assembly 110 about adhesion collar 40, 41 and adhesion collar 46, 47 of a partially assembled PTE 2. As depicted in FIG. 12, the containment assembly 110 can be placed about pins 162, 163, 164, 165 that engage the cuffs 120, 122. Although FIG. 12 depicts four pins 162, 163, 164, 165 it is to be understood that the reinforcement stretching tool 160 can have more pins to ensure that the containment assembly is extended radially in all directions during installation. Cuffs 120, 122 can be radially stretched to increase the internal diameter of the cuffs 120, 122 to a diameter larger than an outer diameter of the of the deflated balloons 16, 18 (not shown) and the adhesion collars (38, 39), (40, 41) and (46, 47) (adhesion collars (38, 39) and (46, 47) being visible in FIG. 12). Once the containment assembly is radially stretched, the catheter shaft 12 that has had balloons 16, 18 (not shown) bonded thereto can be inserted into the stretching tool 160. The containment assembly 110 can be positioned about the expander balloon 18 (not shown) when cuffs 120, 122 are radially extended. The pins 162, 163, 164, 165 can be retracted and the cuffs 120, 122 can be adhesively bonded to the expander balloon 18 at the adhesion collars (40, 41) and (46, 47). Additional features may be incorporated into PTE 2. For example, PTE 2 may include a hydrophilic surface that is bonded to the catheter outer surface 32 of the PTE 2. Useful hydrophilic surface materials include any hydrogel and/or hydrophilic surface treatments applicable to hydrophobic elastomers. The surface materials can help to avoid urethra irritation and/or other complications within the urethra. Also, indwelling catheters present a path for infection. As such, a prophylactic antibiotic may be incorporated in the hydrophilic surface. Alternatively, the antibiotic may be applied by the physician who could soak the expander in an antibiotic solution before placing it in the patient. Examples of hydrogel surfaces and antibiotics that may be impregnated into the PTE 2 are disclosed in United States patent application 08/791 ,514, the entire content of which is incorporated herein by reference.

Referring to FIG. 1, a method for treating BPH using the PTE 2 can proceed as follows. A medical practitioner can select an appropriately sized PTE 2 according to known principles for selecting a urethral catheter, e.g., using a calibration catheter to determine the appropriate PTE 2 size. Commercially, PTE 2 could be made available in a variety of sizes so as to conform to varying lengths of the prostatic urethra. Measuring distances to determine the proper PTE 2 to use are known and include those disclosed in U.S. patent 4,660,560 and 5,002,558. The PTE 2 can be prepared for insertion into the urethra, e.g., by sterilizing and lubricating the PTE 2. Distal tip 10 may be inserted into the male urethra until distal tip 10, urine port 14 and positioning balloon 16 enter the bladder. Although not always necessary, a stylet can be used to aid PTE 2 insertion into the male urethra. The stylet functions to stiffen the catheter and facilitate overcoming prostatic obstructions. A preferred stylet can match the cross-sectional profile of the urine passageway lumen 26 of PTE 2 to maximize the stiffness of the stylet.

FIG. 13 depicts a PTE 2 following insertion into the male urethra and at a point during the positioning of PTE 2 when both the positioning balloon 16 and the expander balloon 18 are in at least a partially inflated condition. Referring to FIG. 1 and to FIG. 13, the catheter shaft 12 can be inserted into a patient's urethra 168 so as to place the positioning balloon 16, distal tip 10, and urine port 14 within the patient's bladder 169. The positioning balloon 16 can be inflated by infusing an inflation liquid, such as saline, using an inflation syringe (not shown) attached to an inflation control valve 170. The inflation liquid can enter the positioning balloon lumen 28 by passing through the inflation control valve 170, which can be coupled to the positioning balloon lumen 28 via lumen 22 and eyelet 44 (FIG. 3), thereby inflating the positioning balloon 16. During the inflation of the positioning balloon 16 and prior to inflation of the expander balloon 18, it may be necessary to apply some force to the PTE 2 to ensure that the positioning balloon 16 does not pull the PTE 2 too far into the urethra 168. After the positioning balloon 16 is inflated, the expander balloon 18 should be properly located within the region of the urethra surrounded by or coincident with the prostate 172, which is generally indicated by the length of the urethra 168 between reference numerals 174, 176. The expander balloon 18 can be partially inflated using an inflation syringe (not shown) attached to an inflation control valve 24. The inflation liquid can enter the lumen 24 by passing through inflation control valve 24, which can be coupled to the expander balloon lumen 30 via lumen 24 and eyelet 50 (FIG. 3) thereby inflating the expander balloon 18. Preferably, the expander balloon 18 is inflated just enough to positionally secure the expander balloon 18.

A partially inflated expander balloon 18 enclosed within the exposed containment assembly 110 can positionally secure the PTE 2 within the urethra channel. Typically, about 3 ml of the inflation liquid will suffice to positionally secure the PTE 2 within the urethra. At this point, the positioning balloon 16 can be deflated using the inflation syringe to remove the inflation fluid (not pictured in FIG. 13). After the positioning balloon 16 is deflated, the expander balloon 18 can be more fully inflated by adding additional inflation liquid. When more fully inflating the expander balloon, the medical practitioner can take care so as to not create a commissurotomy. Alternatively, it is to be understood that expander balloon 18 can be more fully inflated before deflating the positioning balloon 16. Fully inflating both the positioning balloon 16 and the expander balloon 18, however, can cause excessive pressure on the patient's bladder neck 180, which is preferably between the positioning balloon 16 and the expander balloon 18. Therefore, partially inflating the expander balloon 18 and then deflating the positioning balloon 16 can provide a method for positionally securing the PTE 2 while minimizing patient discomfort. When the positioning balloon 16 is deflated while the expander balloon 18 is at least partially inflated, the pressure exerted on the patient's bladder neck by the balloons 16, 18 can be alleviated and yet the PTE 2 can remain secured in place due to the traction provided by the exposed containment covering disposed about the expander balloon 18. Releasing the pressure on the patient's bladder neck can greatly improve the comfort level of the patient. The exposed yams of containment assembly 110 (not shown) can prevent the

PTE 2 from being displaced within the urethra 168 even though the positioning balloon 16 has been deflated. In particular, the exposed fibers of the containment assembly 110 provide traction between an inner wall 182 of the urethra 168 and the expander balloon 18. This traction between the containment assembly 110 disposed about the expander balloon 18 and the inner wall 182 prevents the PTE 2 from being displaced. While not being limited to a specific mechanism, it is thought that the exposed containment assembly 110 acts somewhat like chains on an automobile tire to provide traction.

After being positionally secured, the PTE 2 can be inflated to its initial dilation size and connected to a urine collection bag (not shown) via urine funnel 184 (FIG.

1). Connecting the PTE 2 to a urine collection bag allows the PTE 2 to remain within the patient for extended periods of time, e.g., hours, days or months. At subsequent time points that are determined by a medical practitioner, the expander balloon 18 can be more fully expanded or deflated depending on a patient's needs. Thus, by increasing the expander balloon's 18 diameter slowly, e.g., over hours or days, the prostatic urethral pathway can be enlarged without a concomitant commissurotomy. That is, the prostatic urethral pathway can be enlarged incrementally with each increase in the expander balloon 18 diameter being less than the largest attainable diameter. Incremental inflation of the expander balloon 18 can be used to enlarge the prostatic pathway without causing a commissurotomy. Additionally, the prostatic urethral pathway can be enlarged slowly so as to allow the prostate to accommodate the PTE 2 expansion, which may allow for a more complete and longer lasting improvement in the diameter of the prostatic urethral pathway compared to other comparable methods. For example, the expander balloon 18 can be enlarged to at least about 75% of its attainable diameter during the first day of treatment and incrementally enlarged to its final diameter in less than about 7 days. The expander balloon 18 can be enlarged to less than about 75% of its attainable diameter during the first day of treatment and incrementally enlarged to its final diameter in less than about 7 days. Variable initial inflation of the expander balloon 18 can vary according to the discomfort level that the patient is willing to endure. The PTE 2 may be secured in the patient for less than about 7 days. The PTE 2 may be secured in the patient for less than about 30 days or the PTE 2 may be secured in the patient for greater than about 30 days and less than about 60 days. Securing the PTE 2 within the patient for shorter periods of time can be advantageous for the patient because the patient is relieved of the PTE 2 sooner. However, under certain circumstances longer treatment periods may increase effectiveness of the treatment. Since the PTE 2 may remain in a patient for extended periods of time, it is preferred that the inflation solutions described herein be a sterile isotonic fluid. Useful inflation fluids include 0.9% sterile saline solutions and/or any other acceptable isotonic fluids. In addition, it may be useful to use an isotonic radiopaque inflation solution that provides a contrasting solution. In another aspect, an article of manufacture can be provided that includes packaging material and a prostatic tissue expander catheter contained within the packaging material. The prostatic tissue expander may conform substantially to PTE 2 as shown in FIG. 1, and can be effective for treating a human patient having benign prostatic hypertrophy. Also included in or with the packaging material is a label, package insert or other human readable indicia that indicates that inserting a prostatic tissue expander within a urethra of a patient; inflating a positioning balloon so as to properly position an expander balloon within a portion of the urethra being coincident with a prostate of the patient; inflating the expander balloon so as to secure the prostatic tissue expander within the urethra of the patient, and deflating the positioning balloon is effective for treating a human patient suffering from benign prostate hypertrophy. Any known packaging and printing methods may be used to prepare the article of manufacture.

The foregoing detailed description has been provided for a better understanding of the invention and is for exemplary purposes only. Modifications may be apparent to those skilled in the art without deviating from the spirit and scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A prostatic tissue expander comprising: a urethral catheter; a positioning balloon disposed about the urethral catheter; an expander balloon disposed about the urethral catheter; and a containment assembly disposed about the expander balloon, the containment assembly limiting a degree of distension of the expander balloon, and wherein the containment assembly comprises a plurality of yams, at least some of the ya s of the containment assembly being exposed.

2. The prostatic tissue expander of claim 1 , wherein the containment assembly is distensible.

3. The prostatic tissue expander of claim 1 , wherein the containment assembly is effective for producing a uniform radial expansion of the expander balloon along a longitudinal axis of the expander balloon.

4. The prostatic tissue expander of claim 1, wherein the containment assembly is effective for returning the expander balloon from an inflated condition to an uninflated condition when an inflation solution is removed from the expander balloon.

5. The prostatic tissue expander of claim 1 , wherein the yams of the containment assembly include a knitted component.

6. The prostatic tissue expander of claim 1, wherein the containment assembly includes a knitted component interlaced with a woven component.

7. The prostatic tissue expander of claim 1, wherein the containment assembly includes a jersey stitch knitted component.

8. The prostatic tissue expander of claim 5, the knitted component including at least one distensible, yam and at least one substantially non-distensible ya .

9. The prostatic tissue expander of claim 8, wherein the distensible yam includes a polyurethane yam.

10. The prostatic tissue expander of claim 8, wherein the substantially nondistensible yam is selected from yams fabricated using materials from the group consisting of nylon, polypropylene, polyester, polyethylene and aramid.

11. The prostatic tissue expander of claim 8, the substantially nondistensible yam being polyethylene.

12. The prostatic tissue expander of claim 11 , wherein the substantially non-distensible yam includes an ultra high molecular weight polyethylene.

13. The prostatic tissue expander of claimδ, the distensible yam being polyurethane and the substantially non-distensible yam being polyethylene.

14. The prostatic tissue expander of claim 13, wherein the substantially non-distensible yarn includes an ultra high molecular weight polyethylene.

15. The prostatic tissue expander of claim 1 , the expander balloon being expandable to at least about 100 French.

16. The prostatic tissue expander of claim 1 , the expander balloon being expandable to a radial diameter of at least about 120 French.

17. The prostatic tissue expander of claim 1 , the expander balloon being expandable to a radial diameter of at least about 150 French.

18. The prostatic tissue expander of claim 1 , further comprising a second reinforcement, the second reinforcement being circumferentially wrapped about an end of the containment assembly to hold a portion of the containment assembly about the expander balloon.

19. The prostatic tissue expander of claim 1 , further comprising a reinforcement material, the reinforcement material being circumferentially wrapped about an end of the containment assembly and the reinforcement material providing hoop strength to the containment assembly.

20. The prostatic tissue expander of claim 1 , wherein the expander balloon includes an adhesion collar comprising at least one adhesive pocket for receipt of an adhesive that bonds the expander balloon to the urethral catheter.

21. The prostatic tissue expander of claim 20, wherein the adhesion collar comprises at least one annular projection that comprises a radiused surface for contacting an outer surface of the urethral catheter.

22. The prostatic tissue expander of claim 20, wherein the adhesive pocket comprises at least one radiused comer.

23. The prostatic tissue expander of claim 1, wherein the positioning balloon comprises at least one adhesive pocket for receipt of an adhesive that bonds the positioning balloon to the urethral catheter.

24. The prostatic tissue expander of claim 1 , wherein the containment assembly has an exposed outer surface for contact with an interior wall of a urethra of a patient.

25. The prostatic tissue expander of claim 1 , wherein the containment assembly is effective for securing the expander balloon within a urethra of a patient.

26. The prostatic tissue expander of claim 1, wherein the urethral catheter further comprises a urine port, a first lumen for inflation and deflation of the positioning balloon, a second lumen for inflation and deflation of the expander balloon, and a third lumen for fluid communication with the urine port to discharge urine from the urethral catheter.

27. The prostatic tissue expander of claim 1 , wherein the containment assembly has a first end disposed within a first cuff and a second end disposed within a second cuff, the first and second cuffs securing opposite ends of the containment assembly about the urethral catheter.

28. The prostatic tissue expander of claim 1, wherein the containment assembly has a first end disposed within a first cuff and a second end disposed within a second cuff, the first and second cuffs securing opposite ends of the expander balloon about the urethral catheter, and the first and second cuffs securing opposite ends of the containment assembly about the urethral catheter.

29. The prostatic tissue expander of claim 27, wherein at least a portion of the first end or the second end of the containment assembly disposed within at least one of the cuffs is stretched.

30. The prostatic tissue expander of claim 27, wherein at least a portion of the first end or second end of the containment assembly disposed within at least one of the cuffs is stretched longitudinally.

31. The prostatic tissue expander of claim 29, the cuffs being impregnated with an elastomeric matrix.

32. The prostatic tissue expander of claim 1 , further comprising a reinforcement material, the containment assembly being reinforced with the reinforcement material.

33. The prostatic tissue expander of claim 32 wherein the reinforcement material is effective for providing hoop strength to the containment assembly.

34. The prostatic tissue expander of claim 33 wherein the reinforcement material comprises a non-distensible fiber.

35. The prostatic tissue expander of claim 34 wherein the reinforcement material is circumferentially wrapped about at least one exterior surface of the expander balloon, the containment assembly or both the expander balloon and the containment assembly.

36. The prostatic tissue expander of claim 32 wherein the reinforcement material comprises a fiberglass fiber.

37. The prostatic tissue expander of claim 36 wherein the containement assembly further comprises cuffs, and wherein the reinforcement material is circumferentially wrapped about the exterior surface of the cuffs.

38. The prostatic tissue expander of claim 24, the expander balloon being expandable to a radial diameter of at least about 100 French.

39. The prostatic tissue expander of claim 24, the expander balloon being expandable to a radial diameter of at least about 120 French.

40. The prostatic tissue expander of claim 24, the expander balloon being expandable to a radial diameter of at least about 150 French.

41. The prostatic tissue expander of claim 1 further comprising a second containment assembly disposed about the positioning balloon, wherein a least some of the fibers of the containment assembly are exposed.

42. A method for securing a prostatic tissue expander within the prostatic urethra comprising: inserting a prostatic tissue expander into a urethra of a patient, the prostatic tissue expander including a urethral catheter, a positioning balloon disposed about the urethral catheter, and an expander balloon disposed about the urethral catheter; inflating the positioning balloon in a bladder of the patient so as to position the expander balloon within a portion of the urethra coincident with a prostate of the patient; partially inflating the expander balloon so as to secure the prostatic tissue expander within the urethra of the patient; and deflating the positioning balloon.

43. The method of claim 42, further comprising applying a force to the urethral catheter before partially inflating the expander balloon so as to draw the positioning balloon against a bladder neck of the bladder of the patient.

44. The method of claim 42, further comprising further inflating the expander balloon to a desired inflation size following the deflation of the positioning balloon.

45. The method of claim 42 wherein the expander balloon is partially inflated with an isotonic solution.

46. A method for treating benign prostatic hypertrophy comprising the steps of: inserting a prostatic tissue expander into a urethra of a patient, the prostatic tissue expander including a urethral catheter, a positioning balloon disposed about the urethral catheter, and an expander balloon disposed about the urethral catheter; inflating the positioning balloon in a bladder of the patient so as to position the expander balloon within a portion of the urethra coincident with a prostate of the patient; partially inflating the expander balloon so as to secure the prostatic tissue expander within the urethra of the patient; and deflating the positioning balloon.

47. The method of claim 46 wherein the expander balloon is partially inflated with an isotonic solution.

48. The method of claim 46, the further comprising more fully inflating the expander balloon after deflating the positioning balloon.

49. The method of claim 46, further comprising maintaining the prostatic tissue expander balloon secured in the patient for less than about 30 days.

50. The method of claim 46, further comprising maintaining the prostatic tissue expander balloon secured in the patient for less than about 7 days.

51. The method of claim 46, further comprising maintaining the prostatic tissue expander balloon secured in the patient for greater than about 30 days and less than about 60 days.

52. The method of claim 46, further comprising incrementally inflating the expander balloon.

53. The method of claim 52, the incrementally inflating the expander balloon comprising the steps of: inflating the expander balloon for a first time to at least about 75% of a maximum diameter of the expander balloon; and inflating the expander balloon a second time to a diameter greater than the first time.

54. The method of claim 52, the incrementally inflating the expander balloon comprising the steps of: inflating the expander balloon for a first time less than about 75% of a maximum diameter of the expander balloon; and inflating the expander balloon a second time to a diameter greater than the first time.

55. The method of claim 52, further comprising incrementally inflating the expander balloon over a period of days less than about 30 days.

56. The method of claim 52, further comprising incrementally inflating the expander balloon over a period of days greater than about 30 days and less than about

60 days.

57. The method of claim 46, the expander balloon being inflated to a radial diameter of at least about 70 French.

58. The method of claim 46, the expander balloon being inflated to a radial diameter of at least about 90 French.

59. The method of claim 46, the expander balloon being inflated to a radial diameter of at least about 100 French.

60. The method of claim 46, the expander balloon being inflated to a radial diameter of at least about 150 French.

61. A method for manufacturing a containment assembly of a prostatic tissue expander comprising the steps of: stretching a containment assembly along its longitudinal axis; contacting the stretched containment assembly with an adhesive at specified intervals; and allowing the adhesive to cure.

62. The method of claim 61, the containment assembly being stretched over a rod.

63. The method of claim 62, the rod having an external diameter less than the external diameter of the prostatic tissue expander in the region of a balloon.

64. The method of claim 61 , the containment assembly being stretched to about the maximum longitudinal length of the containment assembly.

65. The method of claim 61, the specified intervals comprising cuff areas.

66. The method of claim 61 , the method further comprising stretching the containment assembly at intervals comprising cuffs.

67. An expander balloon for use in a prostatic tissue expander comprising an elastomeric balloon and at least one adhesion collar for securing a portion of the balloon to a catheter.

68. The expander balloon of claim 67, wherein the adhesion collar comprises at least one adhesive pocket for receipt of an adhesive that bonds the expander balloon to a urethral catheter shaft.

69. The expander balloon of claim 68, wherein the adhesion pocket comprises at least one minor diameter and at least one major diameter, the minor diameter being sized smaller than an outer diameter of the urethral catheter shaft.

70. The expander balloon of claim 68, wherein the adhesive pocket comprises at least one radiused comer.

71. The expander balloon of claim 69, wherein the adhesive pocket comprises at least one annular projection comprising at least one radiused comer, the radiused comer being disposed on a portion of the annular projection adjacent to a surface of the adhesive pocket that defines the major diameter.

72. The expander balloon of claim 71, wherein a second corner of the annular projection is disposed adjacent to a surface of the annular projection contacting the urethral catheter shaft, the second comer being substantially square.

73. An article of manufacture comprising packaging material and a prostatic tissue expander contained within the packaging material, the packaging material further comprising a label or package insert indicating that inserting a prostatic tissue expander within a urethra of a patient; inflating a positioning balloon so as to properly position an expander balloon within a portion of the urethra being within a prostate of the patient; inflating the expander balloon so as to secure the prostatic tissue expander within the urethra of the patient; and deflating the positioning balloon can be effective for treating a patient suffering from benign prostate hypertrophy.