A ready-to-use urinary catheter assembly

Abstract: A urinary catheter assembly comprising a urinary catheter (1) having on at least a part of its surface a hydrophilic surface layer (6) intended to produce a low-friction surface character of the catheter by treatment with a liquid swelling medium prior to use of the catheter and a catheter package (7) having a cavity (11) for accommodation of the catheter (1). The package (7) includes a compartment (12) having walls of a gas impermeable material and accommodating said liquid swelling medium or a catheter pretreated therewith for long time preservation of said low-friction surface character and provision of a ready-to-use catheter assembly.

Description: This invention relates to at least one urinary catheter assembly comprising a urinary catheter having on at least a part of its surface a hydrophilic surface layer intended to produce a low-friction surface character of the catheter by treatment with a liquid swelling medium prior to use of the catheter and a catheter package made of a gas impermeable material and having a cavity for accommodation of the catheter. Urinary catheters of the kind to which the invention pertains are known, inter alia, from EP-A-0 217 771, EP-A-0 586 324 and WO 94/16747, whereas various forms of catheter packages are known from US-A-3,035,691, US-A-3,648,704, US-A-3,967,728 US-A-4, 204, 527, US-A-4,269,310, US-A-4,379,506, US-A-5,454,798, GB-A-2,284,764, DE-A-2,317839, EP-A-0 677 299 and DK Design Registration No. 0932 1986. US-A-3,648,704, US-A-3,967,728, US-A-4,269,310, GB-A-2,284,764 and EP-A-0 677 299 disclose a conventional urinary catheter assembly comprising a catheter of the kind where prior to insertion of the catheter into the urethra the tip of the catheter is to be lubricated with a gel-like lubricant and a package where such a lubricant is accommodated in a rupturable pouch connected with or located within the package itself adjacent to the tip of the catheter or supplied together with the catheter package for connection therewith prior to use of the catheter An important feature of any urinary catheter used for intermittent catherisation of the bladder of an incontinent user is the ability of the catheter to slide easily through the urethra without exposing the urethral walls to any risk of damage. Catheters of the kind to which the inventions pertains have been developed to meet this need by imparting an extremely low friction character to at least the part of the surface of the catheter which is actually introduced into the urethra. The low friction surface character is obtained by incorporating into the relevant part of the catheter at least a hydrophilic surface layer, typically in the form of a coating, and exposing this layer or coating to contact with a liquid swelling medium immediately prior to us. In order to maintain the low friction surface character during location of the catheter in the urethra and subsequent with drawal therefrom and hereby reduce stinging pain it is further known to incorporate an osmolality promoting agent, such as NaCl, in the hydrophilic coating. When catheters of this kind are used directly by end users outside the medical environment of a hospital or a clinic, e.g. by or tetraplegic patients who often have a very poor dexterity, and therefore need a very simple insertion procedure, the most common liquid swelling medium used for preparation of the catheter immediately prior to use would be normal tap water. In order to reduce the risc of infection inherent with the performance of intermittent catherisation of the bladder both the actual swelling medium used and the environment in which the catherisation is performed need, however, to be as clean and antiseptic as possible. Evidently, this need may be very difficult to meet in many daily life situations, as where catherisation must be performed outside the users normal daily environment, e.g. in public toilets, where neither the water supply nor the general state of cleanliness can be expected to be of a sufficiently high standard. Moreover, many disabled users have severe difficulties in entering available toilet rooms due to simple physical barriers like narrow access ways, stairs and the like. On this background, it is the object of the invention to improve and facilitate the performance of intermittent urinary catherisation in any type of environment by providing a ready to use urinary catheter assembly comprising a catheter which can be withdrawn from its package and is prepared for direct insertion in the urethra and in a substantially sterile condition, whereby the general quality of life for users of intermittent catherisation would be greatly improved. In order to meet this and other objects of the invention, as set forth in the following, a urinary catheter according to the invention is characterised in that the cavity accommodates said liquid swelling medium for provision of a ready-to-use catheter assembly. The term "gas impermeable" material should be understood in this context to mean any material that will be sufficiently tight against diffusion by evaporation of the actual liquid swelling medium for a period exceeding the recommended shelf life time of the catheter assembly which could be up to five years, typically 36 months. In a first series of embodiments of the urinary catheter assembly of the invention the catheter package as a whole is made of a gas impermeable material and the compartment for the liquid swelling medium is in liquid flow communication with the cavity for accommodation of the catheter. In one preferred embodiment of this kind the catheter package may be formed from two sheets of gas impermeable film material connected with each other by a gas impermeable joint defining said compartment and the cavity for accommodating the catheter. The compartment for the liquid swelling medium is entirely integrated with the cavity for the catheter, whereby the hydrophilic surface layer of the catheter will be activated immediately after completion of the production process, when the swelling medium has been introduced in the package. The gas-impermeable walls of the package will then protect the activated coating from drying out and provide a long time preservation of the low friction surface characteristic of the catheter until the moment of actual use. The joint between the two sheets of film material of the package may advantageously be a welded joint which may be formed to allow easy opening of the package for withdrawal of the prepared catheter. Such a welded joint may comprise a part at the end of the package providing a peel-off joint to separate said sheets from each other for withdrawal of said catheter frog the package. In order to reduce the amount of liquid swelling medium required for activation of the hydrophilic surface coating of the catheter, the latter many advantageously be provide with means preventing said swelling medium from getting into contact with internal or external surface parts of the catheter not provided with said hydrophilic layer for an activation period during which said medium is applied to the surface part provided with said hydrophilic layer. In the following, the invention will be explained in more detail by means of various embodiments illustrated in the accompanying drawings, in which figures 1 and 2 are an upper plan view and a cross-sectional view, respectively, of a first embodiment of a urinary catheter assembly according to the invention; figure 3 shows a modification of the embodiment in figs. 1 and 2; figures 4 and 5 are a side view and a cross-sectional view, respectively, of a second embodiment; figure 6 shows a modification of the embodiment in figs 4 and 5 ; figure 12 is a plan view of an eighth embodiment; figure 13 illustrates a part of a catheter provided with means to reduce the amount of liquid swelling required for activation of a hydrophilic surface coating. In the embodiment shown in figs. 1 and 2 the urinary catheter assembly of the invention is intended for intermittent catherisation of the bladder of a user and comprises a urinary catheter 1 having a catheter tube 2 with cross-sectional and longitudinal dimensions suitable for introduction of the catheter through the urethra. The catheter tube 2 extends from a distal inlet end 3, in which urine inlet openings 4 are provided, towards a proximal end, at which the catheter tube is connected with an outlet member 5 designed for connection of the catheter with a hose member (not shown) for transport of urine withdrawn from the bladder to a urine collection bag (not shown). On a substantial part of its length from the distal end the catheter tube is, in the illustrated embodiment, coated on its external surface with a hydrophilic surface coating 6 of a kind known per se, which by preparation with a liquid swelling medium prior to use of the catheter provides an extreme low friction character of the catheter surface to enable the catheter to slide very easily through the urethra without exposing the urethral walls to any risk of damage. A hydrophilic surface layer may, however, be provided by other means and may include a catheter tube of which the active part to be located in the urethra is made entirely of a hydrophilic material. The catheter 1 is accommodated in its entirety in a package 7 formed by two sheets 8 and 9 of a gas-impermeable thermoplastic film material such as a multiple layer film material comprising e.g. aluminium, welded together along a welding seam 10 which constitutes a joint defining a cavity 11 narrowly surrounding the catheter tube 2 and a widened end section 12 joining the cavity 11 through a transitional section 13 matching the external dimensions of the outlet or connector member 5. The widened end section 12 forms a compartment for accommodation of the liquid swelling medium which is to be used for preparation of the catheter by activation of the low friction surface character of the hydrophilic surface coating 6. The liquid swelling medium may be any liquid suitable for this purpose and may typically comprise an isotonic or non-iotonic aqueous solution e.g. of sodium chloride or sterile water. In order to maintain the swelling medium in liquid state until the actual preparation of the catheter the liquid swelling medium is confined in the embodiment shown in a storage body 14 which as described above may be of a spongy or gel-like material located in the compartment or end section 12. The catheter 1 and the spongy body 14 may both be arranged in the package 7 in a sterile or antiseptic condition prior to welding the two sheets 8 and 9 of film material together to form the finished urinary catheter assembly. Prior to the intended use of the catheter 1 the hydrophilic surface coating 6 is prepared to activate its low friction character by applying an external pressure to the end section or compartment 12 to squeeze the liquid swelling medium out from the spongy body and allow it to flow into the cavity 11. Since the welding seam 10 is arranged to provide a narrow cavity 11 around the catheter tube 2 the amount of swelling liquid needed for preparation of the hydrophilic coating 6 can be kept sufficiently low to be easily accommodated in the body 14 of spongy material. Experiments have verified that by suitable design of the cavity the amount of swelling liquid may be reduced to a volume of 2 to 50 ml, preferably 2 to 15 ml for female catheters and 5 to 30 ml for male catheters. The period needed for preparation of the hydrophilic surface coating 6 will typically be about 30 seconds and subsequently the catheter 1 may be withdrawn from the package 7 in a ready to use condition. To facilitate withdrawal of the catheter 1 from the package 7 the welding joint may in the transitional section 13 comprise a part forming a tear-off joint 15 permitting the entire end section or compartment 12 to be separated from the package 7, whereby the catheter 1 may as a whole be withdrawn from the package by gripping the outlet or connector member 5 only, while maintaining the catheter tube 2 in a sterile condition for insertion into the urethra with a minimum risc of infection. As another possibility for easy withdrawal of the prepared catheter 1 from the package 7 the welding joint may, as illustrated in figure 3, comprise a part 10a adjacent the distal end of the catheter tube providing a peel-off joint permitting easy separation of plastic film sheets 8 and 9. Thereby, the package 7 itself will serve as an applicator to be gripped by the user to permit introduction of the catheter tube without contamination. Due to the gas-impermeability of the package 7 it is not necessary to use a body 14 of spongy material to accommodate the liquid swelling medium. The swelling medium may be introduced in the package during the assembling operation prior to completion of the welding and will thereby immediately prepare the hydrophilic coating. The package will itself prevent the coating from drying out and preserve the low friction character of the surface coating to keep the catheter in a ready to use condition at all times. This would have the inherent advantage that no preparation step is required immediately prior to use, whereby the operation will be reduced to opening of the package 7 for immediate withdrawal of the catheter without the delay resulting from the required preparation period. Since the preparation period is very short and the possible presence of surplus swelling liquid in the package may be uncomfortable to the user who in many situations will have to carry one or more catheter assemblies with him or her, it would frequently be preferred, however, to keep the swelling medium confined in the spongy body 14 until the moment of actual use. In the alternative embodiments to be described in the following the catheter 1 may be of the same design as described above and will therefore not be explained in further detail. For easy withdrawal of the catheter 1 from the package 16 after preparation of the hydrophilic coating the package may include a fracture defining segment 20 provided at the transitional region between the first and second tubular parts 17 and 19 of the package. As an alternative possibility the compartment 19 may be formed with an open proximal end closed by a removable plug-like closure member 21 which should preferably engage the spongy body 14 for removal thereof together with the closure member and provide access to the catheter outlet or connector member 5. The embodiment shown in figs. 4 and 5 may be modified as shown in figure 6 by designing the first and second tubular parts 22 and 23, respectively, as separate parts which are detachably connected with each other by a coupling member 24 providing a gas-impermeable seal against both of the tubular parts 22 and 23. In figure 12 the package 51 is formed integrally with a urine collecting bag 52. For disabled users like paraplegics or tetraplegics who as described in the foregoing may have severe difficulties in entering available toilet rooms such an integration of the urine collecting bag with the catheter package is a significant practical advantage making the use of the catheter totally independant of the availability of a toilet room. The catheter 1 is located in a relatively narrow tapering part 53 joining the collection bag 52. In this case, the catheter 1 will in use not be completely removed from package 51. Instead the distal end of the tapering part 53 may be opened by peel-off separation of two plastic film sheets from which the package 51 is composed. Thereby, the catheter 1 may after preparation of the hydrophilic coating be introduced by an operation similar to the one described above for the embodiment in figure 3. Due to the desirability of limiting the amount of swelling liquid to be contained in the swelling liquid compartment in those embodiments where the swelling liquid is transferred directly through the cavity narrowly surrounding the catheter tube 2 to the hydrophilip coating 6, i.e. without having to flow internally through the catheter tube 2 and through the catheter inlet openings 4, the catheter may be provided with means preventing the swelling liquid from getting into contact with internal or external surface parts of the catheter 1 not provided with the hydrophilic coating 6, during the period needed for preparation of the hydrophilic coating to activate its low friction character. Such means may in a simple manner comprise the application of a film layer 55 of a material soluble by the actual swelling medium to said internal or external surface parts. As shown in figure 13 this may be done in the most simple way by application of such film layers 55 over the catheter inlet openings 4. Thereby, substantially the entire quantity of swelling medium will be effectively used for the preparation of the hydrophilic surface coating. Whereas different embodiments of ready to use urinary catheter assemblies according to the invention have been described in the following the invention is not limited to the specific characteristics of these embodiments, but will include numerous modifications without departing from the scope of the patent claims. Thus, a catheter assembly according to the invention may well comprise a number of catheters packed in individual packings all arranged in a common package providing the prescribed gas impermeability.

Claims: A urinary catheter assembly comprising at least one urinary catheter (1) having on at least a part of its surface a hydrophilic surface layer (6) intended to produce a low-friction surface character of the catheter by treatment with a liquid swelling medium prior to use of the catheter and a catheter package (7, 16, 29, 34, 42, 46, 51, 51') having a cavity (11, 18, 39, 48, 53) for accommodation of the catheter (1), characterized in that the cavity accommodates said liquid swelling medium for provision of a ready-to-use catheter assembly. A catheter according to claim 1, characterized in that the catheter package (7) as a whole is made of a gas impermeable material. A urinary catheter assembly as claimed in claim 2, characterized in that the catheter package (7) is formed from two sheets (8, 9) of gas impermeable film material connected with each other by a gas impermeable joint (10) defining the cavity (11) for accommodating the catheter (1) and the liquid swelling medium. A urinary catheter assembly as claimed in claim 3, characterized in that the catheter package (7) is of a general elongate shape with said joint (10) arranged to define said cavity (11) to accommodate the catheter (1) in a substantially linear orientation. A urinary catheter assembly as claimed in claim 3 or 4, characterized in that said joint (10) is arranged 10 provide said cavity (11) with a cross-section narrowly surrounding the catheter (1). A urinary catheter assembly as claimed in any of claims 3 to 5, characterized in that said joint (10) is a welding joing. A urinary catheter assembly as claimed in claim 6, characterized in that said welding joint (10) comprises at least a part (10a) at the end of the package remote from said compartment (12) providing a peel-off joint to separate said sheets (8, 9) from each other for withdrawal of said catheter (1) from the package (7). A urinary catheter assembly as claimed in any of the preceding claims, characterized in that the catheter (1) is provided with means preventing said swelling medium from getting into contact with internal or external surface parts of the catheter not provided with said hydrophilic coating (6) for an activation period during which said medium is applied to the surface part provided with said hydrophilic coating (6). A urinary catheter assembly as claimed in claim 8, characterized in that said means comprises a film layer (55) of a material soluble by said swelling medium applied to said parts not provided with said hydrophilic coating. A urinary catheter assembly as claimed in any of the preceding claims, characterized in that said package includes a bag (52) communicating with the catheter (1) for collection of urine. A urinary catheter assembly as claimed in any of the preceding claims, characterized in that said liquid swelling medium is selected from the group comprising an aqueous solution, an isotonic aqueous solution, an isotonic aqueous solution of sodium chloride and sterile water.

Inventors: KAYEROD HELLE, NOSTED ULRIK, TANGHOJ ALLAN, TORSTENSEN JAN, KAYEROD, HELLE, NOSTED, ULRIK, TANGHOJ, ALLAN, TORSTENSEN, JAN
Applicants: COLOPLAST AS, COLOPLAST A/S
Application year: 1997
Main classification: A61M25
IPC codes: A61M25, A61L29, A61M1