Access member and a system for catheterization of the urinary bladder through an artificial or a natural canal in a user, and a method of replacing such an access member

An access member for use in catheterization having an outer end and an inner end. The access member, which is adapted to extend from the outside of the body through a canal extending from the user's abdominal wall to the bladder and into the bladder, has at least one cavity extending substantially throughout the length of the access member. The walls of the access member are made from a flexible material such that the cavity is generally kept closed by the mutual contact of the walls while allowing for intermittent insertion of a catheter.

This is a nationalization of PCT/DK00/00361, filed Jul. 3, 2000 and published in English.

BACKGROUND OF THE INVENTION

The present invention relates to an access member and a system for catheterization of the urinary bladder through an artificial or a natural canal in a user. The invention furthermore relates to a method of replacing such an access member

Catheterization may typically be necessary in the case of postoperative urine retention of newly operated patients in a hospital. Another typical use is with patients suffering from severe cases of urinary incontinence as for disabled individuals like para- or tetraplegics who frequently have no control permitting voluntary urination.

Traditionally, such catheterization is carried out by inserting a catheter through the urethra of the patient. The catheter may be left in place for permanent catheterization during several hours or days, which is typically the case in elderly and infirm patients, or be retracted after emptying of the bladder, ie. so-called intermittent catheterization (IC).

Access to the urinary bladder may likewise be desirable in order to introduce eg. pharmaceuticals into the bladder or in order to wash or rinse the bladder.

Intermittent urethral catheterization performed with intervals of eg. 3 to 6 hours reduces the risk of infection of urethra and the bladder significantly as compared to permanent catheterization and has for many users become increasingly common also in daily life situations outside the clinical environment of a hospital, whereby a significantly improved quality of life has been obtained for this group of patients.

However, intermittent catheterization requires a certain degree of dexterity and mobility which implies that self-catheterization is not always possible, especially in women where the urethral orifice may be difficult to locate.

During recent years, suprapubic catheterization (SPC) has been introduced as an alternative to urethral catheterization. In suprapubic catheterization, a canal is made from the surface skin of the abdominal wall of a user into the bladder under local or general anaesthetia and by means of a pointed hollow introducer or trocar. After penetration of the trocar into the bladder, a catheter is inserted through the canal thus provided, the inner end of said catheter being retained in the bladder by means of eg. an inflatable balloon abutting the inner wall of the bladder after retraction of the trocar. Although many of the disadvantages connected with urethral catheterization, such as eg. urethral cleavage and urethritis, may be overcome by this technique, infection risk is still high as suprapubic catheterization is typically performed as permanent catheterization due to the fact that the canal may close during replacement of the catheter. Furthermore, the fact that the end of the catheter protrudes well into the bladder when using a balloon, which is necessarily placed at a distance from the end in order to allow in-flow of urine, means that the bladder wall may be injured, the more so as the bladder wall often assumes an at least partially collapsed position in which it rests on the end of the catheter.

GB patent No. 2 275 420 discloses a system for suprapubic catheterization of the bladder permitting intermittent catheterization by means of an accessor or sealing member permanently lodged in the artificial canal. The accessor comprises an outer shell formed by two elongate leaves of a bendable plastics material which are hinged together along one edge and having flanges at one end for securing the accessor to the skin surface. A sealing means in the form of a balloon assembly keeps the canal formed in the accessor closed between emptyings but allows insertion of the catheter. Due to the size and material of the accessor, this system may cause discomfort to the user.

Another alternative is provided by the so-called Mitrofanoff principle, by which a suprapubic canal is surgically made by removing parts of a body section, such as the appendix, another part of the intestinal system, eg. a section of the ileum, or any other suitable tubular body tissue, and subsequently attaching one end of the section to the abdominal skin surface whereas the other end penetrates the bladder wall and possibly protrudes into the bladder, the part being attached to the bladder wall at the point of penetration. Obviously, this technique requires surgery under general anaesthetia and implies a loss of bowel or other tissue as well as stitches in the bladder wall.

U.S. Pat. No. 5,704,353 discloses a catheter for temporary placement in the female urethra. The catheter comprises a shaft which in one end has a sealing portion and in the other end a cap. In the lumen of the shaft a one-way valve is enclosed, urine being drained upon activation of the valve by means of a spike. As the length of the shaft has to be adapted to the individual length of the user's urethra and due to the rather elaborate design, this device is expensive and complicated in manufacture. Furthermore, the presence of the sealing portion, which is designed as a mushroom-shaped crown and which in the position of use rests against the inner surface of the bladder, may cause discomfort to the user.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an access member for use in catheterization of the urinary bladder, which is comfortable to wear and which at the same time provides for an appropriate security against leakage.

It is a further object to provide an access member, by which intermittent catheterization may be performed by a larger group of users and which alleviates the problems encountered in the prior art.

These and other objects are met by an access member adapted to be, in a position of use, accommodated in an artificial or a natural canal in a user, said access member having an outer end and an inner end defining a predetermined length and extending, in the position of use, from the outside of the body of the user through said canal and into the urinary bladder, and comprising at least one wall defining at least one cavity extending substantially throughout said predetermined length, said at least one cavity being intended for intermittently receiving a catheter, said access member being characterized in that said at least one wall of the access member has such a degree of flexibility that said at least one cavity is kept in a substantially closed position by the mutual contact of parts of said at least one wall, but allows for intermittent insertion of a catheter.

The flexibility of the wall or walls of the access member entail that the access member itself is able to provide for the necessary sealing properties, as the access member will inherently have the effect of an automatic non-return valve. In case the access member is exposed to forces in the radial or longitudinal directions, the wall of the access member is pressed against itself or, alternatively, the walls are pressed against each other, thus closing the through-going cavity of the access member between catheterizations, either by a collapse in the radial direction and/or by a bend at the entrance into the bladder. At the inner end of the access member, the cavity is kept closed eg. by contraction of the detrusor and possibly by the pressure exerted by the urine collected in the bladder. By integrating the sealing properties in the access member, it is possible to make the access member according to the invention very comfortable to wear.

During use in connection with suprapubic catheterization, in which the body canal is an artificial canal extending from the user's abdominal wall, contraction of the abdominal muscles keeps the part of the through-going cavity of the access member, which is situated in the region of the abdominal wall, closed, so that urine may not penetrate to the outside and consequently that eg. water may not seep into the bladder when the user is washing or bathing. Nevertheless, intermittent catheterization may be carried out without difficulty by inserting the catheter through the passage provided by the cavity or cavities of the access member.

In relation to the Mitrofanoff principle, the access member according to the invention does not necessarily require surgery under general anaesthetia or any loss of body tissue. By this design an access member is provided which makes intermittent catheterization a feasible and/or attractive alternative to a large number of users which hitherto have been forced to use permanent catheterization. As a consequence, it is possible to reduce the risk of infection in this group of users.

The wall or walls of the access member may comprise a foil or film material, or a foam or a gel. It is likewise possible to form at least a part of the wall or walls of the access member of a net material of eg. metal.

The access member may comprise one wall forming a substantially hose-shaped access member, which provides for a simple manufacture of the access member. The access member may eg. be produced by extrusion or by any other method which provides a preferably seam-less access member.

Alternatively, the access member may comprise at least two walls which are formed by sheets of material having substantially larger dimensions in the longitudinal direction than in the transverse direction and being joined at the respective longitudinally extending edges. By this design, a particularly effective sealing is provided. The sheets may eg. be joined by means of welding, adhesion or any other suitable joining technique.

In order to control the insertion of the access member properly, said sheets may have different thicknesses and different degrees of flexibility. Hereby, it is possible to control the rigidity in the axial direction of the access member.

In an embodiment, which is particularly advantageous with respect to the insertion, at least one blind hole is provided in at least one of said sheets.

In a further embodiment, in which there are at least three sheets and two cavities, and which is particularly advantageous with respect to the insertion as well, one of said cavities is closed at a distance from the outer end of the access member.

In both of these latter embodiments, a suitable fluid, eg. air, may be introduced into the blind hole alternatively the closed cavity, thus increasing the rigidity of the access member in the longitudinal direction thereof during insertion of a catheter whereby the insertion is facilitated.

In an embodiment, which is relatively simple to manufacture and which provides for an easy insertion, the inner end of the access member is designed as a cap having a number of openings.

The access member may furthermore comprise means for securing the outer end of the access member to the abdominal skin surface. Said means may eg. comprise a plate-shaped member, which may be fastened to the skin surface by means of sewing or by adhesion.

In order to provide for additional security against leakage into the access member from the outside, a plug may be provided for introduction into the outer end of said at least one through-going cavity.

In another aspect of the invention, a system for catheterization is provided.

In yet another aspect, a method of replacing an access member is provided. Replacement of the access member may take place by removing the existing access member and shortly after inserting the new access member. If necessary, the new access member may be introduced through the existing one while still in place, whereafter the old one is removed.

DETAILED DESCRIPTION OF THE INVENTION

InFIGS. 1 and 2a system for suprapubic catheterization is shown, in which an access member1is shown in its position of use in a canal extending from the skin surface2of the abdominal wall of the user, which in this case is a female, to the urinary bladder3, said canal extending above the pubic bone4. The access member1is essentially formed as a hollow tube made from a suitable flexible material. The term “tube” should be interpreted in its broadest sense, ie. as comprising any element having at least one longitudinally extending cavity.

The wall or walls of the access member is/are formed with a small thickness, which in this respect means that the thickness should be sufficiently low so as to be able to allow parts of one wall, or different walls to contact each other. A preferred thickness depends on the material chosen.

Examples of suitable materials are eg. film or foil made from polyethylene, polyurethane, poly-propylene or like material, a flexible foam made from any suitable material, artificial blood vessels, pig guts, Tripsin, a gel, such as a hydrogel or a silicone gel which are widely used for eg. implants or any other gel, or any other material which can meet the demands to the access member, both with respect to physical properties and bio-compatibility. In addition to being flexible and being able to be produced in a small thickness, the material should thus preferably be soft, possess low surface friction, be able to be coated, welded, heat-sealed and/or glued, adhered or joined using any other suitable joining technique and be hydrophobic. Furthermore, the material should be able to collapse in a radial direction but preferably be stable axially, and could for insertion purposes be rolled up. With respect to the bio-compatibility of the material, it should prevent stenosis, encrustation and bio-film formation, not form in-growth with tissue and be non-toxic.

Parts of the access member may comprise different materials. For instance, the part situated in the region of the abdominal wall could be designed of a net material of for example, metal.

In order to prevent or reduce even further these unwanted effects, the access member may be provided with a coating on the outer side and/or the inner side. The coating may eg. contain antibacterial agents or disinfectants known per se, such as metal ions, halogen ions, antibiotics or sulpha. It is also possible that the wall or walls of the access member may have properties allowing slow release of any known antibacterial or disinfective substances.

The access member1has an outer end1awhich may be secured to the skin surface2by any suitable means, eg. a medical grade adhesive, and an inner end1bwhich protrudes well into the bladder3, the outer and inner ends1a,1bdefining a predetermined length. Examples of suitable adhesives are adhesives based on styrene-isoprene-styrene block polymer (SIS), polyisobutylene (PIB), Silicone Tacky Gel, polyvinylether (PVE) and acrylic polymers. In the embodiment shown, the cavity in the access member1extends throughout the predetermined length such that a catheter5may be inserted through the canal provided by the access member1in order to attain the catheterization position as shown inFIG. 1, in which urine flows from the bladder3through inlet openings5aprovided at the end of the catheter and out to a suitable draining means (not shown).

After catheterization, the catheter5is retracted from the bladder3through the access member1which remains seated in the body of the user.

As indicated inFIG. 2the access member1assumes, at least partially, a flattened position between catheterizations as a result of the involuntary contraction of the detrusor and abdominal muscles, and of the pressure exerted by the urine collected in the bladder, respectively. Consequently, the passage between the bladder3and the outside of the body provided by the cavity in the access member is kept closed such that virtually no urine may penetrate to the outside. Moreover, the closure of the canal implies that liquid such as water will not seep into the bladder when the user for example washes, takes a shower or bathes.

Initial positioning of the access member1may take place by first penetrating the abdominal wall and the wall of the bladder3by means of a trocar and by subsequently inserting a catheter or other applicator means carrying on its outer or inner side the access member1.

In order to insert the access member1without discomfort to the user, the exterior surface of the access member may be provided with a coating to provide a slippery low-friction surface character. In order to retain the access member safely within the body the coating may be of a temporary character such that the exterior surface after a predetermined period of time looses its low-friction character.

Alternatively, application of the access member may take place as shown inFIG. 3, showing a part of an embodiment of the inventive system comprising a catheter25and an access member21. In this embodiment, an inner end21bof the access member21adapted to be positioned at the end of the catheter25provided with urine inlet openings25ais designed as a cap having openings21cwhich allow urine to flow into the catheter25through the inlet openings25a.

In the following, different designs of the access member will be described with reference toFIGS. 4 to 8. In these very schematic cross-sectional views, certain details of the access member may be omitted, ie. the access member may comprise parts not indicated in theses Figures.

In its most simplified form as shown inFIG. 4, the access member41comprises only one circumferential wall42which defines a cavity45for receiving a catheter during catheterization, thus providing the access member41with a substantially hose-shaped appearance. It should be noted that the access member41is shown in an open or catheter-receiving position, and it is to be understood that the cavity45is kept closed between catheterizations as parts of the wall42are pressed against each other.

In theFIG. 5embodiment, the access member51comprises two walls which are formed by sheets52,53of material having substantially larger dimensions in the longitudinal direction than in the transverse direction and being joined at the respective longitudinally extending edges. The cavity55defined by the sheets52,53is shown in a slightly open position for reasons of clarity only. In one sheet53, a blind hole54is provided in any suitable manner. During insertion of the access member51into the canal, a suitable fluid, eg. air, is introduced into the blind hole54. As long as the fluid is present in the hole54, the rigidity of the access member in the longitudinal direction thereof is increased, and the insertion of the access member51into the canal is eased.

A similar principle is shown inFIG. 6, in which the access member61comprises three walls likewise formed by sheets62,63,64of any suitable material, of which sheets62and63define the catheter receiving cavity65. The cavity66defined between sheets64and63is closed at a distance from the outer end of the access member, and eg. air may be introduced into the closed cavity66in order to ease insertion of the access member61.

In theFIG. 7embodiment, the sheets72,73forming the walls of the access member71have different thicknesses and may in addition thereto have different degrees of flexibility. In this manner secure closing of the cavity as well as an eased introduction is ensured. In addition or alternatively, the thickness and/or the degree of flexibility may vary in the circumferential direction of the access member.

In the embodiment shown inFIG. 8the cavity85defined by the sheets82,83forming the walls of the access member81is filled with a gel86, which functions partly as a lubricant during insertion of the catheter, partly as an additional security against leakage.

InFIG. 9an access member91which may be of any of the types described in the above is at its outer end91afastened to a plate-shaped member93, eg. by means of a layer of adhesive92or in any other way, such as eg. by forming the plate-shaped member93integrally with the access member91. The plate-shaped member93is in turn fastened to the abdominal skin surface by means of eg. a layer94of medical grade adhesive. A plug member95which is intended to be inserted into the outer end91aof the access member91provides for increased safety against in-seeping of eg. water into the access member91. The plug member95may be coated as described in the above in connection with the coating of the access member itself.

The access member and the system according to the invention may alternatively be used in urethral catheterization. By using an access member in connection with urethral catheterization, self-catheterization may be performed even by users having a reduced dexterity and mobility as an access member facilitates the operation of finding the urethral orifice, especially in women. In contrast to permanent catheterization the muscles are furthermore allowed to contract and relax. By letting the outer end protrude from the urethral orifice, this end may easily be gripped by the user in order to position the catheter correctly. This operation is thus much facilitated in relation to urethral catheterization without an access member and makes it possible for even eg. sclerosis patients to perform intermittent self-catheterization which in turn implies that this group of patients gains a significantly improved quality of life in relation to use of permanent catheterization.

The access member or system may likewise be used for introduction of eg. pharmaceuticals into the urinary bladder or for washing/rinsing the bladder.

The invention is not limited to the embodiments shown and described in the above. Several modifications and combinations of the embodiments shown and described are conceivable within the scope of the appended claims.