IRRIGATION CATHETER

Abstract: The present invention is a catheter (100) and a method for irrigating the urethra (14) in situ in the body comprising a tube (200) having a drain lumen (24), having an irrigation enabling conduit (700), and an irrigation port (66) for supplying irrigation fluid to the exterior of the tube (22). A drain port (35) on the tube enables irrigation fluid to be drained into the drain lumen (24). A proximal balloon (40) which is inflatable by means of irrigating fluid provided by the irrigation enabling conduit (700) enables sealing contact to be established between the balloon, and the urethra when the balloon is inflated, thereby preventing leakage of irrigating fluid to outside the urethra during irrigation. The catheter may also be provided with a distal balloon (60) also inflatable by means of the irrigation enabling conduit (700), thus providing a distal seal between the urethra, and the bladder. Further, the catheter may also be provided with a regular bladder balloon (500) including an inflation enabling conduit (52).

Description: IRRIGATION CATHETER FIELD OF INVENTION The present invention relates to catheters, in particular to urethral catheters adapted for the irrigation of the urethra in situ. BACKGROUND AND PRIOR ART Urinary catheters are often required to remain in-situ in a patient up to 30 to 40 days at a time after its original insertion. It is well known that patients who require an indwelling urethral catheter for more than a few days are very prone to contract infections such as urethritis or cystitis, which may develop into a more serious disease such as pyleonephritis. As the urethral channel is not always sterile, bacteria tend to be transferred to the bladder from the urethral mucose during inseπion of the catheter, for example. The effectively open communication that exists between the patient environment, the urethral canal and the bladder essentially exacerbates the problem of infection. It is also known that regular normal bodily use of the urethral channel to rid the body of liquid waste - not possible when an indwelling catheter is present - results in the irrigation of the urethra and minimises the possibility of such infections arising. Attempts have been made to provide an indwelling catheter with means for irrigating the urethra in situ. For example, US Patent Nos. 4,501,580 and 4,579,554 to Glassman. and US Patent No. 1,045,326 to Ruflin, disclose an indwelling urethral catheter having an external wall comprised of deep grooves, and a fluid passageway and port for delivering irrigation fluid into the grooves and thus to the urethral inner surface. US Patent No. 3,394,705 to Abramson discloses a Folley-type catheter having an internal chamber proximal to the bladder balloon and apertures communicating with the exterior of the catheter and in communication with an irrigation fluid source. However, while these devices enable the urethra to be irrigated with varying degrees of effectiveness, the irrigating fluid that is dispensed with such devices in situ is inevitably allowed to drip into the patient environment. The result is that the patient or medical staff has to make provision to either catch the fluid or. worse, to clean up the spillage after use. The use of such devices therefore tends to extend any disease present in the fluid, and the devices are also not pleasant to use, resulting in a very high degree of non-compliance by patient and/or medical staff, thereby substantially reducing in a very practical manner the real effectiveness of the devices. The present invention aims to overcome the aforementioned disadvantages of the disclosed devices and to enable regular irrigation of the urethra to be effected in an easy and mess-free manner, thus encouraging user compliance, and reducing the incidence and degree of infection. The present invention achieves these aims by providing a urethral catheter with proximal sealing means capable of forming a seal with the urethra, while also enabling the catheter to be inserted into and removed from the catheter. An irrigation enabling conduit enables irrigating fluid to be supplied into the urethra via a distal port, and a drain port located just distal to the proximal sealing means drains accumulated irrigating fluid into the regular drain lumen of the catheter. The catheter may also be provided with a retention balloon for the bladder, as commonly used with this type of urethral catheter. Furthermore, a second, distal sealing means may also be provided on the catheter, for providing a distal seal with the urethra, preventing possible migration of irrigating fluid into the bladder. In the preferred embodiment, the said proximal sealing means comprises inflatable proximal balloon means, capable of being inflated by means of said irrigation enabling conduit, and similarly, the distal sealing means comprise inflatable distal balloon means, capable of being inflated by means of said irrigation enabling conduit. BRIEF DESCRIPTION OF FIGURES Figure 1 illustrates, in longitudinal cross-sectional view, the structural characteristics of a preferred embodiment of the present invention. Figure 2 illustrates, in longitudinal cross-sectional view, the structural characteristics of a second embodiment of the present invention. Figure 3 illustrates, in longitudinal cross-sectional view, the structural characteristics of a third embodiment of the present invention. Figure 4 illustrates, in longitudinal cross-sectional view, the structural characteristics of a fourth embodiment of the present invention. Figure 5 illustrates, in longitudinal cross-sectional view, the structural characteristics of a fifth embodiment of the present invention. Figure 6 illustrates, in longitudinal cross-sectional view, the structural characteristics of a sixth embodiment of the present invention. Figure 7 illustrates, in longitudinal cross-sectional view, the structural characteristics of a seventh embodiment of the present invention. Figure 8 illustrates, in longitudinal cross-sectional view, the structural characteristics of a eighth embodiment of the present invention. Figure 9 illustrates, in longitudinal cross-sectional view, the structural characteristics of a ninth embodiment of the present invention. Figure 10 illustrates, in longitudinal cross-sectional view, the structural characteristics of a tenth embodiment of the present invention. Figure 1 1 illustrates, in longitudinal cross-sectional view, the structural characteristics of a eleventh embodiment of the present invention. Figure 12 illustrates, in longitudinal cross-sectional view, the structural characteristics of a twelfth embodiment of the present invention. Figure 13 is a common transverse sectional view along line A-A of each of the embodiments of Figures 1, 2, 5, 6, 9 and 10. Figure 14 is a common transverse sectional view along line B-B of each of the embodiments of Figures 1 and 9. Figure 15 is a common transverse sectional view along line C-C of each of the embodiments of Figures 1,2 and 6. Figure 16 is a common transverse sectional view along line D-D of each of the embodiments of Figures 1, 2, 5, 6, 9 and 10. Figure 17 is a common transverse sectional view along line E-E of each of the embodiments of Figures 1, 2, 5, 6, 9 and 10. Figure 18 is a common transverse sectional view along line F-F of each of the embodiments of Figures 1 and 2. Figure 19 is a common transverse sectional view along line G-G of each of the embodiments of Figures 2, 5 and 6. Figure 20 is a common transverse sectional view along line H-H of each of the embodiments of Figures 3 and 11. Figure 21 is a transverse sectional view along line I-I of the embodiment of Figure 3. Figure 22 is a common transverse sectional view along line J-J of each of the embodiments of Figures 3, 4, 7, 8, 11 and 12. Figure 23 is a common transverse sectional view along line K-K of each of the embodiments of Figures 3, 4, 7, 8, 1 1 and 12. Figure 24 is a common transverse sectional view along line L-L of each of the embodiments of Figures 3 and 4. Figure 25 is a common transverse sectional view along line M-M of each of the embodiments of Figures 4, 7 and 8. Figure 26 is a transverse sectional view along line N-N of the embodiment of Figure 5. Figure 27 is a common transverse sectional view along line 0-0 of each of the embodiments of Figures 5 and 6. Figure 28 is a transverse sectional view along line P-P of the embodiment of Figure 7 Figure 29 is a common transverse sectional view along line Q-Q of each of the embodiments of Figures 7 and 8. Figure 30 is a common transverse sectional view along line R-R of each of the embodiments of Figures 9 and 10. Figure 31 is a common transverse sectional view along line S-S of each of the embodiments of Figures 9 and 10. Figure 32 is a common transverse sectional view along line T-T of each of the embodiments of Figures 11 and 12. Figure 33 is a common transverse sectional view along line U-U of each of the embodiments of Figures 11 and 12. Figure 34 illustrates in longitudinal perspective view the preferred embodiment of the present invention, with several constant-section portions of the length being broken away. Figure 35 illustrates in longitudinal perspective view the fifth embodiment of the present invention, with several constant-section portions of the length being broken away. Figure 36 illustrates in longitudinal perspective view the ninth embodiment of the present invention, with several constant-section portions of the length being broken away. Figure 37 schematically illustrates the male urethral tract showing the preferred embodiment of the present invention positioned therein in (a) bladder drain mode only; and (b) in urethral irrigation mode (including bladder drain mode). Figure 38 schematically illustrates the male urethral tract showing the fifth embodiment of the present invention positioned therein. Figure 39 schematically illustrates the male urethral tract showing the ninth embodiment of the present invention positioned therein in (a) bladder drain mode only; and (b) in urethral irrigation mode (including bladder drain mode). DESCRIPTION The present invention is defined by the claims, the contents of which are to be read as included within the disclosure of the specification, and will now be described by way of example with reference to the accompanying Figures. In the present specification, the term distal refers to a direction towards and into the patient body, while the term proximal refers to a direction away from the patient body. The present invention relates to a catheter particularly adapted for irrigating the urethra, the catheter, comprising:- an elongated tube insertable into the urethra and having an outer surface, an inner drain lumen, a proximal tube end connectable to a suitable fluid collection reservoir, and a distal tube end insertable into a bladder via the urethra; at least one opening on said outer surface adjacent to said distal tube end providing fluid communication between said drain lumen and the exterior of said elongated tube; suitable proximal sealing means capable of allowing said tube to be reversibly inserted within the urethra and capable of forming a seal with the urethra inner surface, and disposed on said tube at a first distance from and proximal to said distal tube end such that when said catheter is fully inserted into the bladder via the urethra, said proximal sealing means is located within the urethra and forms a seal therewith; at least one irrigation enabling conduit extending along at least a portion of the length of said tube for enabling irrigation of exterior of said elongated tube, said at least one irrigation enabling conduit comprising:- at least one irrigation conduit port in direct or indirect fluid communication with the exterior of the tube, a proximal irrigation conduit end connectable to a first external fluid source and at least one drain port providing fluid communication between the exterior of said elongated tube and said drain lumen. Optionally, the catheter further comprises:- inflatable bladder balloon means adjacent and proximal to said distal tube end such that when said catheter is fully inserted into the bladder via the urethra, said bladder balloon means is capable of inflation within the bladder to a size sufficiently large to substantially prevent removal of said catheter from the bladder; at least one inflation enabling conduit extending along at least a portion of the length-of said elongated tube and having a second inflation port in fluid communication with the interior of said bladder balloon means and a proximal inflation conduit end connectable to a second external fluid source for enabling inflation of said bladder balloon means, wherein said proximal inflation conduit end comprises a oneway valve to prevent back flow or leakage of fluid therefrom. Additionally, the catheter may further optionally comprise:- distal sealing means capable of allowing said tube to be reversibly inserted within the urethra and capable of forming a seal with the urethra inner surface, and disposed on said tube at a second distance from and proximal to said distal tube end, such that when said catheter is fully inserted into the bladder via the urethra, said distal sealing means is located within the urethra and forms a seal therewith. Thus, in the preferred embodiment of the present invention, and with reference to Figures 1, 13 to 18, 34 and 37, the catheter (100) comprises an elongated tube (200), proximal sealing means (400), an at least one irrigation enabling conduit (700), inflatable bladder balloon means (500), and distal sealing means (600). The said elongated tube (200) is of diameter generally smaller than the urethra (11) and is thus insertable into the urethra (11), and is preferably made from a medically-compatible resilient material including latex and silicon. The said tube (200) has an outer surface (22), an inner drain lumen (24), a proximal tube end (26) connectable, in any suitable manner, to a suitable fluid collection reservoir (not shown), and a distal tube end (28) insertable into a bladder (12) via the urethra (1 1). Thus, the said proximal tube end (26) may be connected to a suitable fluid collection reservoir, which may be disposable or reusable, and examples thereof are many and known. The catheter (100) further comprises at least one opening (30) on said outer surface (22) adjacent to, or alternatively at, said distal tube end (28) providing fluid communication between said drain lumen (24) and the exterior of said elongated tube, in particular the inner volume (13) of the bladder ( 12), thus enabling fluid buildup in the bladder to be drained into the said fluid collection reservoir via said drain lumen (24). The said proximal sealing means (400) are capable of allowing said tube (200) to be reversibly inserted within the urethra (11) and is also capable of forming a seal with the urethra inner surface (14). The said proximal sealing means (400) are disposed on said tube (200) at a first distance (dl) from and proximal to said distal tube end (28) such that when said catheter (100) is fully inserted into the bladder (12) via the urethra ( 1 1), said proximal sealing means (400) is located within the urethra (1 1) and forms a seal therewith. In the preferred and other embodiments, said proximal sealing means (400) comprises inflatable proximal balloon means (40) on said outer surface (22) of .said tube (200). Further, the said at least one irrigation enabling conduit (700) (hereinafter described) comprises at least one first inflation port (72) in fluid communication with the interior (48) of said proximal balloon means (40) for enabling inflation of said proximal balloon means (40). Said proximal balloon means (40) is capable of being inflated to a diameter at least slightly larger than that of the urethra inner surface ( 14) such as to enable a proximal area of sealing contact (15) to be established between the urethra inner surface (14) and the said proximal balloon means (40), and furthermore, said proximal balloon means (40) have a reduced diameter when deflated such as to enable said tube (200) to be reversibly inserted within the urethra (11). Thus, the said inflatable proximal balloon means (40) is capable of being inflated to a size sufficiently large to form a seal with the urethra inner surface (14), and is disposed on the said tube (200) at a first distance (dl) from, and proximal to, said distal tube end (28) such that, when said catheter (100) is fully inserted into the bladder (12) via the urethra (11), the said proximal balloon means (40) remains located within the urethra. Typically, said proximal balloon means (40) comprises a stretchable annular skin (42), preferably made from a medically compatible material, and suitably adhered circumferentially at a proximal end (44) and at a distal end (46) thereof onto the outer surface (22) of the tube (200), with suitable adhesion means, as known in the art. Alternatively, said proximal balloon means (40) may be made in a similar manner to the bladder balloon means (500), as hereinafter described. Optionally, said balloon means (40) are substantially flush with the said outer surface (22) when deflated. In the preferred embodiment, (dl) is chosen such that the proximal balloon means (40) are located as close to the proximal end of the urethra as possible, while being able to provide adequate sealing contact between the inflated proximal balloon means (40) and the urethra inner surface (14). The actual optimal value of (dl) will thus depend on the size of the urethra (11), and will thus vary according to age, sex and other physical characteristics of the patient. For a male adult patient, (dl) may typically lie in the range between 12 cm and 18 cm, preferably at approximately 16 cm, though (dl) may be greater than 18 cm or smaller than 12 cm. At least one irrigation enabling conduit (700) extends along the length of said tube (200) for enabling irrigation of the exterior (16) of said elongated tube (200), typically comprising a section of the urethra inner surface (14) located between the proximal and distal areas of sealing contact, (15) and (17), respectively, formed between the inflated proximal balloon means (40) and distal balloon means (60) (hereinafter described), and the urethra inner surface (14). In the embodiments described herein, the catheter (100) comprises a single irrigation enabling conduit (700), though it is possible for the catheter (100) to have more than one separate or interlinked irrigation enabling conduits. The irrigation enabling conduit (700) also enables inflation of said proximal balloon means (40) and said distal balloon means (60). Thus, the said irrigation enabling conduit (700) comprises a first inflation port (72) in fluid communication with the interior (48) of said proximal balloon means (40), a distal irrigation conduit port (74) in direct or indirect fluid communication with the exterior (16) of the tube (200), and a proximal irrigation conduit end (76) connectable to a first external fluid source (not shown). Thus, said irrigation conduit end (76) may be connected to a suitable first external fluid source such as a suitable disposable or reusable syringe containing a suitable voiume of irrigation fluid. Typical examples of a suitable irrigation fluid include a suitable saline solution or chlorhexidine. In the preferred and other embodiments, and with reference to Figure 1, for example, the irrigation enabling conduit (700) comprises, for at least part of the length thereof, a longitudinal lumen within the annular wall (23) of the said tube (200), i.e., intermediate between the said inner drain lumen (24) and the said outer surface (22), similar to the inflation enabling conduit (52) of the bladder balloon means (500), methods of incorporating same within a catheter tube annular wall being well known in the art. Alternatively, said irrigation enabling conduit (700) may comprise tube of substantially smaller diameter than said elongated tube (200), suitably adhered to the outer surface (22) thereof, running either longitudinally or helically with respect thereto, or suitably adhered within the said drain lumen (24). In the preferred embodiment, said proximal irrigation conduit end (76) further comprises a one-way valve arrangement (77) to prevent back flow or leakage of fluid therefrom. The said at least one irrigation conduit port (74) is proximal to said at least one opening (30) and distal to said proximal sealing means (400), in this embodiment the said proximal balloon means (40), such that when said catheter (100) is fully inserted into the bladder (12) via the urethra (11), said irrigation conduit port (74) is located within the urethra ( 1 1). Further, the said at least one irrigation conduit port (74) is on, or alternatively within, or alternatively proximal to said distal sealing means (600), in this embodiment the said distal balloon means (60) (hereinafter described), and distal to said proximal sealing means (400), in this case the said proximal balloon means (40), such that when said catheter (11) is fully inserted into the bladder (12) via the urethra (11), said irrigation conduit port (74) is located within the urethra (11). The said catheter (100) further comprises at least one drain port (35), situated distally to said proximal sealing means (400), in this embodiment the proximal balloon means (40), such that when said catheter (1 1) is fully inserted into the bladder (12) via the urethra (11), said drain port (35) is located within the urethra (11). Preferably, said at least one drain port (35) is located proximally with respect to said at least one irrigation conduit port (74), and said at least one drain port (35) is adjacent and distal to said proximal sealing means (400). Alternatively, this arrangement may be reversed such that the drain port (35) lies at the distal end of the catheter (though on or proximal to the distal sealing means (600), and the at least one irrigation conduit port (74) is located towards the proximal end of the catheter (though on, within or distal to the said proximal sealing means (400). Thus said at least one drain port (35) may located distally with respect to said at least one irrigation conduit port (74), with the advantage that the irrigation enabling conduit (700) may thus be shorter. Thus, in the preferred embodiment, said at least one drain port (35) is adjacent, and distal to, said proximal balloon means (40), providing fluid communication between the said drain lumen (24) and the exterior (16) of said elongated tube (200), particularly the portion of the urethra inner surface between and the said proximal and distal areas of sealing contact, (15) and (17), respectively. In the preferred embodiment, the catheter (100) further comprises inflatable bladder balloon means (500) which are located adjacent, and proximal to, said distal tube end (28) such that when said catheter (100) is fully inserted into the bladder (12) via the urethra (11), said bladder balloon means (500) is capable of inflation within the bladder (12) to a size sufficiently large to substantially prevent removal of said catheter (100) from the bladder (12). At least one inflation enabling conduit (52) for enabling inflation of said bladder balloon means (500) extends along the length of said elongated tube (200) and has at least one second inflation port (54) in fluid communication with the interior (56) of said bladder balloon means (500), as well as a proximal inflation conduit end (58). Of course, the bladder balloon means (500) may comprise more than one inflation enabling conduit (52), either separate or interlinked. Typically, said inflation enabling conduit (52) comprises, for at least part of the length thereof, a longitudinal lumen within the annular wall (23) of the said tube (200), i.e., intermediate between the said inner drain lumen (24) and the said outer surface (22), this arrangement being common in the art. The said proximal inflation conduit end (58) typically comprises a one-way valve arrangement (59) to prevent back flow or leakage of fluid therefrom, and is connectable to a second external fluid source (not shown). The said second external fluid source may also comprise a suitable disposable or reusable syringe containing a suitable volume of fluid, such as irrigation fluid. Typically, bladder balloon means (including their corresponding inflation enabling conduits), their method of manufacture and their uses with respect to urethal catheters are well known in the art and do not require further description herein. In the preferred and other embodiments, the catheter ( 100) further comprises distal sealing means (600) capable of allowing said tube (200) to be reversibly inserted within the urethra (1 1) and also capable of forming a seal with the urethra inner surface (14). Said distal sealing means (600) are disposed on said tube at a second distance (d2) from and proximal to said distal tube end (28), such that when said catheter (100) is fully inserted into the bladder (12) via the urethra (11), said distal sealing means (600) is located within the urethra (1 1) and forms a seal therewith. Said at least one irrigation conduit port (74) may be located within or optionally proximal to said distal sealing means (600), as hereinafter described. In the preferred and other embodiments, said distal sealing means (600) comprises inflatable distal balloon means (60) on said outer surface (22) of said tube (200), wherein said irrigation enabling conduit (700) further comprises at least one third inflation port (78) in fluid communication with the interior (62) of said distal balloon means (60) for enabling inflation of said distal balloon means (60). Said distal balloon means (60) is capable of being inflated to a diameter at least slightly larger than that of the urethra inner surface (14) such as to enable a distal area of sealing contact (17) to be established between the urethra inner surface (14) and the said distal balloon means (60), and said distal balloon means (60) have a reduced diameter when deflated such as to enable said tube (200) to be reversibly inserted within the urethra (11). Thus, the said inflatable distal balloon means (60) is similar to said proximal balloon means (40) as hereinbefore described, and is thus also capable of being inflated to a size sufficiently large to form a seal with the urethra inner surface (14). The distal balloon means (60) typically comprises a stretchable annular skin (64), and is disposed on said tube (200) at a second distance (d2) from, and proximal to, said distal tube end (28), such that when said catheter (100) is fully inserted into the bladder (12) via the urethra (11), said distal balloon means (60) remains located within the urethra (11). In the preferred embodiment, (d2) is chosen such that the distal balloon means (60) are located as close to and preferably in abutting contact with the distal end of the urethra as possible, when the bladder balloon means (500) is fully inflated and properly seated in the bladder (12) in substantially sealing contact with the internal urethral orifice, i.e., the opening of the bladder into the urethra. At the same time, the distance (d2) should still be such as to ensure that adequate sealing contact is still possible between the inflated distal balloon means (60) and the urethra inner surface (14). The actual optimal value of (d2) is therefore typically invariant with regards to the age, sex and other physical attributes of the patient, being typically in the range between 4 cm and 7 cm, preferably at approximately 5 cm, for an adult patient. Said irrigation conduit port (74) may be located on an exposed portion of said outer surface (22) of the tube (200), as shown, for example, in Figures 2 and 4 for the second and fourth embodiments, respectively, and thus provide direct communication between the irrigation enabling conduit (700) and the exterior (16) of the tube (200). Alternatively, said distal irrigation conduit port (74) may be suitably located anywhere on said tube (200), though preferably between just proximal to said distal balloon means (60) and just distal to said drain port (35). Alternatively, and in the preferred and other embodiments, said at least one irrigation conduit port (74) is said third inflation port (78), and said distal balloon means (60) further comprises at least one opening thereon (66) for providing fluid communication between the interior (62) of said distal balloon means (60) and the exterior (16) of said tube (200) between said proximal balloon means (40) and said distal balloon means (60). Thus, the irrigation conduit port (74) is located on a portion of the said outer surface (22) inside said distal balloon means (60), and the said irrigation conduit port (74) may also function as the third inflation port (78), as shown, for example, in Figure 1. At least one distal balloon port (66) on the distal facing portion of the said distal balloon means (60) enables the said irrigation conduit port (74) to provide indirect communication between the irrigation enabling conduit (700) and the exterior (16) of the tube (200). Alternatively, one or more grooves on the tube outer surface (22) extending proximally from inside the distal balloon means (60) to at least past the said distal balloon means (60) may also provide fluid communication between the irrigation enabling conduit (700) and the exterior (16) of the tube (200). Optionally, at least a portion of said outer surface (22) disposed between said irrigation conduit port (74) and said drain port (35) comprises at least one primary groove extending therebetween. In the preferred embodiment, and with reference to Figures 1 and 8. a plurality of primary grooves (38) are arranged longitudinally along said elongated tube (200). Optionally, said primary grooves (38) may be arranged helically around said elongated tube (200). The preferred embodiment optionally further comprises a plurality of secondary grooves (not shown) interconnecting adjacent pair of said primary grooves (38), and typically the said secondary grooves may be arranged circumferentially or helically along and around said elongated tube (200). The arrangement of primary grooves (38), and optional said secondary grooves, assists in distributing irrigation fluid delivered through said irrigation conduit port (74) into said exterior ( 16) to be more homogeneously distributed therein, ensuring more effective irrigation of substantially the whole urethra inner surface (14), between the proximal and distal areas of sealing contact (15) and (17). The said primary grooves (38) (and similarly the secondary grooves) may be in the form of a protruding structure on the surface (22) of the tube (200), as illustrated in Figure 1 and 16. Alternatively, the primary grooves (38) (and similarly the secondary grooves) may be in the form of channels extending into the said surface (22). A second embodiment of the present invention, illustrated in Figures 2, 13, 15, 16, 17, 18, and 19 , comprises the same structural elements as the preferred embodiment, with the exception of the said inflatable distal balloon means (60) (including said third inflation port (78)), as hereinbefore described, mutatis mutandis. A third embodiment of the present invention, illustrated in Figures 3, 20, 21, 22, 23 and 24, comprises the same structural elements as the preferred embodiment, with the exception of the inflatable bladder balloon means (500) (including the said inflation conduit (52), the second inflation port (54), the proximal inflation conduit end (58) and valve arrangement (59)), as hereinbefore described, mutatis mutandis. A fourth embodiment of the present invention, illustrated in Figures 4, 22, 23, 24 and 25, comprises the same structural elements as the preferred embodiment, with the exception of the said inflatable bladder balloon means (500) (including the said inflation conduit (52), the second inflation port (54), the proximal inflation conduit end (58) and valve arrangement (59), and the said inflatable distal balloon means (60) (including said third inflation port (78)), as hereinbefore described, mutatis mutandis. A fifth embodiment of the present invention, illustrated in Figures 5, 13, 16, 17, 19, 27, 35 and 38, comprises the same structural elements as the preferred embodiment, with the exception of the said inflatable distal balloon means (60) (including said third inflation port (78)) and said proximal balloon means (40) (including said first inflation port (72)), as hereinbefore described, mutatis mutandis. In the fifth embodiment of the present invention, the said proximal sealing means (400) comprises proximal spacing means (440) on said outer surface (22) of said tube (200), wherein said proximal spacing means (440) comprises a diameter slightly larger than that of the urethra inner surface (14) such as to allow said tube to be reversibly inserted within the urethra (11) and to enable a seal to be formed between the urethra inner surface (14) and the said proximal spacing means (440). In other words, said proximal spacing means (440) has an external dimension large enough to enable a suitable area of sealing contact (15) to be established between the said urethra inner surface (14) and the proximal spacing means (440). while being small enough to enable the catheter (100) to be inserted into the urethra (1 1) and bladder (12) albeit with a degree of stretching of the urethra walls which is at worst tolerable by the patient and at best minimal and painless. Preferably, said proximal spacing means (440) comprises a suitably dimensioned proximal ring (444), which may be bonded onto said outer surface (22) or alternatively may be formed integrally with the tube (200). In the fifth embodiment of the present invention, the said distal sealing means (600) comprises distal spacing means (660) on said outer surface (22) of said tube (200), wherein said distal spacing means (660) comprises a diameter slightly larger than that of the urethra inner surface (14) such as to allow said tube (200) to be reversibly inserted within the urethra (1 1) and to enable a seal to be formed between the urethra inner surface (14) and the said distal spacing means (660). In other words, said distal spacing means (660) has an external dimension large enough to enable a suitable area of sealing contact (17) to be established between the said urethra inner surface (14) and the distal spacing means (660), while being small enough to enable the catheter (100) to be inserted into the urethra (1 1) and bladder (12) albeit with a degree of stretching of the urethra walls which is at worst tolerable by the patient and at best minimal- and painless. Preferably, said proximal spacing means (660) comprises a suitably dimensioned distal ring (666), which may be bonded onto said outer surface (22) or alternatively may be formed integrally with the tube (200). In the fifth embodiment, said irrigation conduit port (74) may be located on an exposed portion of said outer surface (22) of the tube (200), as shown for example on Figure 5. Alternatively, said irrigation port (74) may be located on a proximally facing portion of said distal spacing means (660). A sixth embodiment of the present invention, illustrated in Figures 6, 13,15, 16, 17, 19 and 27, comprises the same structural elements as the fifth embodiment, with the exception of the said distal spacing means (660), as hereinbefore described, mutatis mutandis. A seventh embodiment of the present invention, illustrated in Figures 7, 22, 23, 25, 28 and 29, comprises the same structural elements as the fifth embodiment, with the exception of the inflatable bladder balloon means (500) (including the said inflation conduit (52), the second inflation port (54), the proximal inflation conduit end (58) and valve arrangement (59)), as hereinbefore described, mutatis mutandis. A eighth embodiment of the present invention, illustrated in Figures 8, 22, 23, " 24 and 25, comprises the same structural elements as the fifth embodiment, with the exception of the said inflatable bladder balloon means (500) (including the said inflation conduit (52), the second inflation port (54), the proximal inflation conduit end (58) and valve arrangement (59), and the said distal spacing means (660), as hereinbefore described, mutatis mutandis. A ninth embodiment of the present invention, illustrated in Figures 9, 13, 14, 16, 17, 30, 31, 36 . and 39, comprises the same structural elements as the preferred embodiment, with the exception of the said distal balloon port (66) as hereinbefore described, mutatis mutandis. In other words, the said irrigation conduit port (74) is located proximally with respect to the said distal balloon means (60), and is thus separate to the said third inflation port (78), as illustrated in Figure 9. In the ninth embodiment, the irrigation enabling conduit (700) further comprises first and second delay means, (80) and (90), respectively. The first delay means (80) substantially delays flow of irrigation fluid through said irrigation conduit port (74) until said proximal balloon means (40) are inflated by said irrigation fluid while the second delay means (90) substantially delays deflation of said proximal balloon means (40) until flow of irrigation fluid through said irrigation conduit port (74) is terminated. Thus, with reference to Figures 9 and 30, said first delay means (80) comprises one-way valve means (82) distal to said first inflation port (72), and biased to open at a predetermined irrigation fluid pressure greater than that required to inflate at least said proximal balloon means (40). In the preferred embodiment, the said one-way valve (82) comprises a resilient flap valve (83), which is superposed over the said distal irrigation conduit port (74). The said resilient flap valve (83) may comprise a stretchable annular skin (84), similar to the annular skin (42) of proximal balloon means (40) and also preferably made from a medically compatible material. However, in contrast to said annular skin (42), said annular skin (84) of the said resilient flap valve (83) is suitably adhered circumferentially only at a distal end (86) thereof onto the outer surface (22) of the tube (200), with suitable adhesion means, as known in the art. The elasticity of annular skin (84) thus enables same to form a reasonably tight annular seal over the portion of the said tube (200) where the said distal irrigation conduit port (74) is located. The elasticity of the said annular skin (84) is also suitably chosen so that the same stretches, at least in the vicinity of the said distal irrigation conduit port (74) when the irrigation fluid pressure exceeds a certain pressure threshold, correlated with the irrigation fluid pressure required to inflate at least said proximal balloon means (40). Thus in this manner, it is ensured that the flow of irrigation fluid through said irrigation conduit port (74) and into the said exterior (16) of the tube (200) is substantially delayed until at least said proximal balloon means (40) is inflated, since the irrigation enabling conduit (700) supplies irrigation fluid to both the proximal balloon means (40) and the irrigation conduit port (74). Preferably, the said resilient flap valve (83) substantially delays flow of irrigation fluid through said irrigation conduit port (74) until both the said proximal balloon means (40) and the said distal balloon means (60) are inflated, since the irrigation enabling conduit (700) supplies irrigation fluid to both the proximal balloon means (40) and the said distal balloon means (60), as well as the irrigation conduit port (74). Optionally, said irrigation conduit port (74) may also comprise an annular groove (not shown) depressed below the said outer surface (22) extending around the circumference of the said tube (200), thereby facilitating further a more homogeneous distribution of irrigating fluid when the same is delivered via said irrigation conduit port (74). Alternatively, the said one-way valve (82) may comprise a spring valve (not shown) having a spring arrangement to maintain the valve in a closed configuration until the irrigation fluid pressure exceeds a certain pressure threshold, as hereinbefore described. The spring valve is thus chosen such that when this pressure threshold is exceeded, the valve opens and allows irrigation fluid to flow through the irrigation conduit port (74) and into the said exterior (16) of the tube (200). Many examples of spring valves suitable for the above purpose are well known. The said spring valve may be located in said irrigation enabling conduit (700), preferably at or near the irrigation conduit port (74). In this embodiment, and with reference to Figures 9 and 31, said second delay means (90) comprises a drainage port (92) on said irrigation enabling conduit (700) for providing fluid communication with said drain lumen (24), said drainage port (92) having a sufficiently small flow area such that irrigation fluid in said irrigation enabling conduit (700) may continuously drain into said drain lumen (24) at a predetermined flow rate, said predetermined flow rate being substantially lower than the irrigation fluid flow rate through said irrigation enabling conduit (700) during irrigation. Thus, so long as irrigation fluid is flowing through said irrigation enabling conduit (700) and through the irrigation conduit port (74) and into the said exterior (16) of the tube (200), irrigation fluid is also being drained, at a substantially lower rate, via said drainage port (92) and into the drain lumen (24), thenceforth preferably into a receptacle such as said fluid collection reservoir for example. However, when fluid flow is terminated from said first external fluid source, the drop in irrigation fluid pressure results in the substantially immediate closure of said first delay means (80). However, in the preferred embodiment both the said distal balloon (60) means and the said proximal balloon means (40) are still substantially in an inflated state, since the irrigation fluid within them can only escape via said second delay means (90), which thus results in a slow deflation of the said distal balloon (60) means and the said proximal balloon means (40). The delay in deflating particularly the said proximal balloon means (40) substantially maintains the integrity of the seal formed at the said proximal area of sealing contact (17), thus enabling irrigation fluid remaining in the exterior (16) of the tube (200) in the urethra at the end of the irrigation process to drain through the drain port (35), before it has a chance to substantially leak out of the urethra and into the patient environment. The said proximal balloon means (40) may be positively biased to inflate before the said distal balloon means (60), prior to irrigation, and to deflate after the said distal balloon means (60) after irrigation, in many different ways. For example, the annular skin (42) of said proximal balloon means (40) may be made from a material which is more easily stretched than the annular skin (64) of the distal balloon means (60). Alternatively, annular skins (42) and (64) may be made from the same stretchable material, though skin (64) may be slightly thicker and therefore require higher pressure to stretch. Alternatively, the geometry and size of the said first inflation port (72), third inflation port (78) and said second delay means (90) may be chosen so that the said proximal balloon means (40) inflates before, and deflates after, the said distal balloon means (60) inflates, and deflates, respectively. A tenth embodiment of the present invention, illustrated in Figures 10, 13, 16, 17, 30 and 31, comprises the same structural elements as the ninth embodiment, with the exception of the said inflatable distal balloon means (60) (including said third inflation port (78)), as hereinbefore described, mutatis mutandis. An eleventh embodiment of the present invention, illustrated in Figures 1 1, 20, 22, 23, 32 and 33, comprises the same structural elements as the ninth embodiment, with the exception of the inflatable bladder balloon means (500) (including the said inflation conduit (52), the second inflation port (54), the proximal inflation conduit end (58) and valve arrangement (59)), as hereinbefore described, mutatis mutandis. A twelfth embodiment of the present invention, illustrated in Figures 12, 22, 23, 32 and 33, comprises the same structural elements as the ninth embodiment, with the exception of the said inflatable bladder balloon means (500) (including the said inflation conduit (52), the second inflation port (54), the proximal inflation conduit end (58) and valve arrangement (59), and the said inflatable distal balloon means (60) (including said third inflation port (78)), as hereinbefore described, mutatis mutandis. The present invention also relates to a method for irrigating the urethra, comprising the steps of:- (la) providing a catheter comprising:- an elongated tube insertable into the urethra and having an outer surface, an inner drain lumen, a proximal tube end connectable to a suitable fluid collection reservoir, and a distal tube end insertable into a bladder via the urethra; at least one opening on said outer surface adjacent to said distal tube end providing fluid communication between said drain lumen and the exterior of said elongated tube; suitable proximal sealing means capable of allowing said tube to be reversibly inserted within the urethra and capable of forming a seal with the urethra inner surface, and disposed on said tube at a first distance from and proximal to said distal tube end such that when said catheter is fully inserted into the bladder via the urethra, said proximal sealing means is located within the urethra and forms a seal therewith; at least one irrigation enabling conduit extending along at least a portion of the length of said tube for enabling irrigation of exterior of said elongated tube, said at least one irrigation enabling conduit comprising:- at least one irrigation conduit port in direct or indirect fluid communication with the exterior of the tube, a proximal irrigation conduit end connectable to a first external fluid source and at least one drain port providing fluid communication between the exterior of said elongated tube and said drain lumen; wherein said proximal sealing means comprises inflatable proximal balloon means on said outer surface of said tube, wherein said at least one irrigation enabling conduit further comprises at least one first inflation port in fluid communication with the interior of said proximal balloon means for enabling inflation of said proximal balloon means, and wherein said proximal balloon means is capable of being inflated to a diameter at least slightly larger than that of the urethra inner surface such as to enable a seal to be formed between the urethra inner surface and the said proximal balloon means, and wherein said proximal balloon means have a reduced diameter when deflated such as to enable said tube to be reversibly inserted within the urethra; (lb) inserting said catheter into the bladder via the urethra such that said inflatable proximal balloon means is located in the urethra; (lc) connecting said proximal irrigation conduit end to said first external fluid source; (Id) providing irrigation fluid from said first external fluid source to said irrigation enabling conduit whereby said proximal balloon means is inflated with irrigating fluid to a size sufficiently large to form a seal with the urethra inner surface, and irrigation fluid is delivered through said irrigation conduit port to at least a portion of the urethra inner surface corresponding to a portion of said elongated tube intermediate between said irrigation conduit port and said drain port, and wherein said delivered irrigation fluid is drained via said drain port. (le) terminating flow of irrigation fluid to said irrigation enabling conduit, whereby flow of irrigation fluid through said irrigation conduit port is terminated, and wherein said proximal balloon means is deflated. Optionally the catheter further comprises:- distal sealing means comprising inflatable distal balloon means on said outer surface of said tube, wherein said at least one irrigation enabling conduit further comprises at least one third inflation port in fluid communication with the interior of said distal balloon means for enabling inflation of said distal balloon means, and wherein said distal balloon means is capable of being inflated to a diameter at least slightly larger than that of the urethra inner surface such as to enable a seal to be formed between the urethra inner surface and the said distal balloon means, and wherein said distal balloon means have a reduced diameter when deflated such as to enable said tube to be reversibly inserted within the urethra, and step (Id) correspondingly further comprises:- inflating said distal balloon means with irrigating fluid to a size sufficiently large to form a seal with the urethra inner surface. Optionally or additionally, the irrigation enabling conduit further comprises first delay means for delaying flow of irrigation fluid through said irrigation conduit port until said proximal balloon means are inflated by said irrigation fluid, second delay means for delaying deflation of said proximal balloon means until flow of irrigation fluid through said irrigation conduit port is terminated; and wherein in step (Id): said first delay means delay delivery of irrigation fluid through said irrigation conduit port until said proximal balloon means are inflated as hereinbefore defined; and in step (le): said second delay means delay deflation of said proximal balloon means until flow of irrigation fluid through said irrigation conduit port is terminated. The present invention also relates to a method for irrigating the urethra, comprising the steps of:- (2a) providing a catheter comprising:- an elongated tube insertable into the urethra and having an outer surface, an inner drain lumen, a proximal tube end connectable to a suitable fluid collection reservoir, and a distal tube end insertable into a bladder via the urethra; at least one opening on said outer surface adjacent to said distal tube end providing fluid communication between said drain lumen and the exterior of said elongated tube; suitable proximal sealing means capable of allowing said tube to be reversibly inserted within the urethra and capable of forming a seal with the urethra inner surface, and disposed on said tube at a first distance from and proximal to said distal tube end such that when said catheter is fully inserted into the bladder via the urethra, said proximal sealing means is located within the urethra and forms a seal therewith; at least one irrigation enabling conduit extending along at least a portion of the length of said tube for enabling irrigation of exterior of said elongated tube, said at least one irrigation enabling conduit comprising:- at least one irrigation conduit port in direct or indirect fluid communication with the exterior of the tube, a proximal irrigation conduit end connectable to a first external fluid source and at least one drain port providing fluid communication between the exterior of said elongated tube and said drain lumen; wherein said proximal sealing means comprises proximal spacing means on said outer surface of said tube, wherein said proximal spacing means comprises a diameter slightly larger than that of the urethra inner surface such as to allow said tube to be reversibly inserted within the urethra and to enable a seal to be formed between the urethra inner surface and the said proximal spacing means; (2b) inserting said catheter into the bladder via the urethra such that said inflatable proximal balloon means is located in the urethra; (2c) connecting said proximal irrigation conduit end to said first external fluid source; (2d) providing irrigation fluid from said first external fluid source to said irrigation enabling conduit whereby irrigation fluid is delivered through said irrigation conduit port to at least a portion of the urethra inner surface corresponding to a portion of said elongated tube intermediate between said irrigation conduit port and said drain port, and wherein said delivered irrigation fluid is drained via said drain port. (2e) terminating flow of irrigation fluid to said irrigation enabling conduit, whereby flow of irrigation fluid through said irrigation conduit port is terminated, and wherein said proximal balloon means is deflated. Optionally, the catheter further comprises:- distal sealing means comprising distal spacing means on said outer surface of said tube, wherein said distal spacing means comprises a diameter slightly larger than that of the urethra inner surface such as to allow said tube to be reversibly inserted within the urethra and to enable a seal to be formed between the urethra inner surface and the said distal spacing means. The present invention also relates to a method for irrigating the urethra as hereinbefore described, further comprising :- (f) connecting said proximal tube end to said fluid collection reservoir. The present invention also relates to a method for irrigating the urethra as hereinbefore described, wherein said catheter further comprises:- inflatable bladder balloon means adjacent and proximal to said distal tube end such that when said catheter is fully inserted into the bladder via the urethra, said bladder balloon means is capable of inflation within the bladder to a size sufficiently large to substantially prevent removal of said catheter from the bladder; at least one inflation enabling conduit extending along at least a portion of the length of said elongated tube and having at least one second inflation port in fluid communication with the interior of said bladder balloon means and a proximal inflation conduit end connectable to a second external fluid source for enabling inflation of said bladder balloon means, wherein said proximal inflation conduit end comprises a one-way valve to prevent back flow or leakage of fluid therefrom; . and wherein step (lb) or (2b) further comprises inserting said catheter into the bladder via the urethra, such that the said bladder balloon means is located within the bladder, connecting said proximal inflation conduit end to said second external fluid source, providing fluid from said second external fluid source to said inflation enabling conduit whereby to inflate said bladder balloon means to a size sufficiently large to substantially prevent removal of said catheter from the bladder, and pulling said catheter in a proximal direction until said inflated bladder balloon means is seated against the bladder opening to the urethra. The present invention also relates to a method for irrigating the urethra as hereinbefore described, further comprising repeating steps (Id) and (le), or (2d) and (2e), a plurality of times. The present invention also relates to a method for irrigating the urethra as hereinbefore described, further comprising deflating said bladder balloon means and removing said catheter from said bladder and urethra. Thus the said preferred embodiment of the invention may be used according to the following method (Figures 37(a) and 37(b)), comprising the following steps. (A) A catheter (100) as hereinbefore described for the preferred embodiment is provided. (B) Said catheter (100) is inserted into the bladder (12) via the urethra (11) such that said inflatable proximal balloon means (40) is located in the urethra (11). (C) It is then ensured that the said bladder balloon means (500) is located within the bladder (12). (D) The said proximal inflation conduit end (58) is connected to said second external fluid source, wherein fluid from said second external fluid source is provided to said inflation enabling conduit (52) to inflate said bladder balloon means (500) to a size sufficiently large to substantially prevent removal of said catheter (100) from the bladder (12). The said catheter (100) is then pulled in a proximal direction until said inflated bladder balloon means (500) is seated against the bladder opening to the urethra (1 1). The catheter (100) may now be used in the normal manner for draining the fluid contents of the bladder ( 12) via said drain port (35) and drain lumen (24) into a convenient receptacle such as the said fluid collection reservoir, in the normal manner as known in the art. (E) The said proximal irrigation conduit end (76) is then connected to said first external fluid source. (F) Irrigation fluid from said first external fluid source is then provided to said irrigation enabling conduit (700) whereby said proximal balloon means (40) is inflated with irrigating fluid to a size sufficiently large to form a seal (15) with the urethra inner surface ( 14). (G) Irrigation fluid from said first external fluid source is also provided for inflating said distal balloon means (60) with irrigating fluid to a size sufficiently large to form a seal (17) with the urethra inner surface ( 14). (H) Irrigation fluid is then delivered through said irrigation conduit port (74) and said distal balloon port (66) to at least a portion of the said urethra inner surface (14) corresponding to a portion of said elongated tube (200) intermediate between said distal balloon port (66) and said drain port (35). The said delivered irrigation fluid is then drained from the urethra (11) via said drain port (35). (I) The flow of irrigation fluid to said irrigation enabling conduit (700) is then terminated, and typically the said distal balloon means (60) followed by the said proximal balloon means (40) are automatically deflated. Typically, said proximal tube end (26) is connected to said fluid collection reservoir prior to the irrigation process, and, steps (F) to (I) may be repeated a plurality of times. The said catheter (100) may then be removed from the patient by deflating said bladder balloon means and removing said catheter (100) from said bladder (12) and urethra (1 1). The corresponding method for said second embodiment of the present invention, comprises the same steps as for the preferred embodiment, with the exception of step (G) and wherein in step (A) a catheter (100) corresponding to the second embodiment is provided, as hereinbefore described, mutatis mutandis. The corresponding method for said third embodiment of the present invention, comprises the same steps as for the preferred embodiment, with the exception of steps (C) and (D) and wherein in step (A) a catheter ( 100) corresponding to the third embodiment is provided, as hereinbefore described, mutatis mutandis, ensuring that in step (G), the distal balloon means (60) is within the urethra (1 1). The corresponding method for said fourth embodiment of the present invention, comprises the same steps as for the preferred embodiment, with the exception of steps (C), (D) and (G) and wherein in step (A) a catheter (100) corresponding to the fourth embodiment is provided, as hereinbefore described, mutatis mutandis, ensuring that at least in step (H), the irrigation conduit port (74) is within the urethra (11). The said fifth embodiment of the invention may be used according to the following method (Figure 38), comprising the following steps. (J) A catheter (100) as hereinbefore described for the fifth embodiment is provided. (K) Said catheter (100) is inserted into the bladder (12) via the urethra (11) such that said proximal spacing means (440) is located in the urethra (11). (L) It is then ensured that the said bladder balloon means (500) is located within the bladder (12). (M) It is then ensured that the said distal spacing means (660) is located in the urethra. (N) The said proximal inflation conduit end (58) is connected to said second external fluid source, wherein fluid from said second external fluid source is provided to said inflation enabling conduit (52) to inflate said bladder balloon means (500) to a size sufficiently large to substantially prevent removal of said catheter (100) from the bladder (12). The said catheter (100) is then pulled in a proximal direction until said inflated bladder balloon means (500) is seated against the bladder opening to the urethra (11). The catheter (100) may now be used in the normal manner for draining the fluid contents of the bladder (12) via said drain port (35) and drain lumen (24) into a convenient receptacle such as the said fluid collection reservoir, in the normal manner as known in the art. (O) The said proximal irrigation conduit end (76) is then connected to said first external fluid source. (P) Irrigation fluid is then delivered through said irrigation conduit port (74) to at least a portion of the said urethra inner surface (14) corresponding to a portion of said elongated tube (200) intermediate between said distal balloon port (66) and said drain port (35). The said delivered irrigation fluid is then drained from the urethra (11) via said drain port (35). (Q) The flow of irrigation fluid to said irrigation enabling conduit (700) is then terminated. Typically, said proximal tube end (26) is connected to said fluid collection reservoir prior to the irrigation process, and, steps (P) and (Q) may be repeated a plurality of times. The said catheter (100) may then be removed from the patient by deflating said bladder balloon means and removing said catheter (100) from said bladder (12) and urethra (11). The corresponding method for said sixth embodiment of the present invention, comprises the same steps as for the fifth embodiment, with the exception of step (M) and wherein in step (J) a catheter (100) corresponding to the sixth embodiment is provided, as hereinbefore described, mutatis mutandis. The corresponding method for said seventh embodiment of the present invention, comprises the same steps as for the fifth embodiment, with the exception of steps (L) and (N) and wherein in step (J) a catheter (100) corresponding to the seventh embodiment is provided, as hereinbefore described, mutatis mutandis. The corresponding method for said eighth embodiment of the present invention, comprises the same steps as for the fifth embodiment, with the exception of steps (L), (M) and (N) and wherein in step (J) a catheter (100) corresponding to the eighth embodiment is provided, as hereinbefore described, mutatis mutandis, ensuring that at least in step (P) the said irrigation conduit port (74) is within the urethra (11). The said ninth embodiment of the invention may be used according to the following method (Figures 39(a) and 39(b)), comprising the following steps. (R) A catheter ( 100) as hereinbefore described for the ninth embodiment is provided. (S) Said catheter (100) is inserted into the bladder (12) via the urethra (11) such that said inflatable proximal balloon means (40) is located in the urethra (11). (T) It is then ensured that the said bladder balloon means (500) is located within the bladder (12). (U) The said proximal inflation conduit end (58) is connected to said second external fluid source, wherein fluid from said second external fluid source is provided to said inflation enabling conduit (52) to inflate said bladder balloon means (500) to a size sufficiently large to substantially prevent removal of said catheter (100) from the bladder (12). The said catheter (100) is then pulled in a proximal direction until said inflated bladder balloon means (500) is seated against the bladder opening to the urethra (1 1). The catheter (100) may now be used in the normal manner for draining the fluid contents of the bladder (12) via said drain port (35) and drain lumen (24) into a convenient receptacle such as the said fluid collection reservoir, in the normal manner as known in the art. (V) The said proximal irrigation conduit end (76) is then connected to said first external fluid source. (W) Irrigation fluid from said first external fluid source is then provided to said irrigation enabling conduit (700) whereby said proximal balloon means (40) is inflated with irrigating fluid to a size sufficiently large to form a seal (15) with the urethra inner surface (14), wherein said first delay means (80) delay delivery of irrigation fluid through said irrigation conduit port (74) until said proximal balloon means (40) are inflated as hereinbefore defined. (X) Irrigation fluid from said first external fluid source is also provided for inflating said distal balloon means (60) with irrigating fluid to a size sufficiently large to form a seal (17) with the urethra inner surface (14), wherein said first delay means (80) also delay delivery of irrigation fluid through said irrigation conduit port (74) until said distal balloon means (60) are also inflated as hereinbefore defined. (Y) Irrigation fluid is then delivered through said irrigation conduit port (74) to at least a portion of the said urethra inner surface (14) corresponding to a portion of said elongated tube (200) intermediate between said irrigation conduit port (74) and said drain port (35). The said delivered irrigation fluid is then drained from the urethra (11) via said drain port (35). (Z) The flow of irrigation fluid to said irrigation enabling conduit (700) is then terminated, and the said second delay means (90) delay deflation of at least said proximal balloon means (40) until flow of irrigation fluid through said irrigation conduit port (74) is terminated. Typically, said proximal tube end (26) is connected to said fluid collection reservoir prior to the irrigation process, and, steps (W) to (Z) may be repeated a plurality of times. The said catheter (100) may then be removed from the patient by deflating said bladder balloon means and removing said catheter (100) from said bladder (12) and urethra (11). The corresponding method for said tenth embodiment of the present invention, comprises the same steps as for the ninth embodiment, with the exception of step (X) and wherein in step (R) a catheter (100) corresponding to the tenth embodiment is provided, as hereinbefore described, mutatis mutandis. The corresponding method for said eleventh embodiment of the present invention, comprises the same steps as for the ninth embodiment, with the exception of steps (T) and (U) and wherein in step (R) a catheter (100) corresponding to the eleventh embodiment is provided, as hereinbefore described, mutatis mutandis, ensuring that in step (X) the proximal balloon means (60) is within the urethra (1 1). The corresponding method for said twelfth embodiment of the present invention, comprises the same steps as for the ninth embodiment, with the exception of steps (T), (U) and (X) and wherein in step (R) a catheter (100) corresponding to the twelfth embodiment is provided, as hereinbefore described, mutatis mutandis, ensuring that at least in step (Y) the said irrigation conduit port (74) is within the urethra (11). Thus, the said catheter (100) enables irrigation of the urethra (11) to be effected in a simple and efficient manner, in a manner that substantially prevents drippage of irrigating fluid (together with possible contaminants from the urethra) from the urethral proximal external orifice. Such irrigation may be carried out any number of times during the life of the catheter, either by the patient him/herself or a nurse or other medical personnel. The simplicity and mess-free advantages of the present invention promotes a high level of user compliance. While in the foregoing description describes in detail only a few specific embodiments of the invention, it will be understood by those skilled in the art that the invention is not limited thereto and that other variations in form and details may be possible without departing from the scope and spirit of the invention herein disclosed. NOMENCLATURE urethra (11) bladder (12) inner volume (13) of the bladder (12) urethra inner surface (14) proximal area of sealing contact (15) exterior (16) of said elongated tube (200) distal area of sealing contact (17) first distance (dl) from, and proximal to, said distal tube end (28) Second distance (d2) from, and proximal to, said distal tube end (28), catheter (100) elongated tube (200) outer surface (22) annular wall (23) an inner drain lumen (24) proximal tube end (26) distal tube end (28) opening (30) drain port (35) primary grooves (38) proximal sealing means (400) proximal spacing means (440) proximal ring (444) inflatable proximal balloon means (40) stretchable annular skin (42) proximal end (44) distal end (46) interior (48) of proximal balloon means Inflatable bladder balloon means (500) inflation enabling conduit (52) second inflation port (54) interior (56) of bladder balloon means (500) proximal inflation conduit end (58) one-way valve arrangement (59) distal sealing means (600) distal spacing means (660) distal ring (666) inflatable distal balloon means (60) interior (62) of said distal balloon means (60) stretchable annular skin (64) distal balloon port (66) irrigation enabling conduit (700) first inflation port (72) distal irrigation conduit port (74) proximal irrigation conduit end (76) one-way valve arrangement (77) third inflation port (78) first delay means (80) one-way valve means (82) resilient flap valve (83) annular skin (84) distal end - (86) second delay means (90) drainage port (92)

Claims: CLATMS:- 1. A catheter, comprising:- an elongated tube insertable into the urethra and having an outer surface, an inner drain lumen, a proximal tube end connectable to a suitable fluid collection reservoir, and a distal tube end insertable into a bladder via the urethra; at least one opening on said outer surface adjacent to said distal tube end providing fluid communication between said drain lumen and the exterior of said elongated tube; suitable proximal sealing means capable of allowing said tube to be reversibly inserted within the urethra and capable of forming a seal with the urethra inner surface, and disposed on said tube at a first distance from and proximal to said distal tube end such that when said catheter is fully inserted into the bladder via the urethra, said proximal sealing means is located within the urethra and forms a seal therewith; at least one irrigation enabling conduit extending along at least a portion of the length of said tube for enabling irrigation of exterior of said elongated tube, said at least one irrigation enabling conduit comprising:- at least one irrigation conduit port in direct or indirect fluid communication with the exterior of the tube, a proximal irrigation conduit end connectable to a first external fluid source and at least one drain port providing fluid communication between the exterior of said elongated tube and said drain lumen. 2. A catheter as claimed in claim 1, further comprising:- inflatable bladder balloon means adjacent and proximal to said distal tube end such that when said catheter is fully inserted into the bladder via the urethra, said bladder balloon means is capable of inflation within the bladder to a size sufficiently large to substantially prevent removal of said catheter from the bladder; at least one inflation enabling conduit extending along at least a portion of the length of said elongated tube and having at least one second inflation port in fluid communication with the interior of said bladder balloon means and a proximal inflation conduit end connectable to a second external fluid source for enabling inflation of said bladder balloon means, wherein said proximal inflation conduit end comprises a one-way valve to prevent back flow or leakage of fluid therefrom. 3. A catheter as claimed in claim 1 or claim 2, further comprising:- distal sealing means capable of allowing said tube to be reversibly inserted within the urethra and capable of forming a seal with the urethra inner surface, and disposed on said tube at a second distance from and proximal to said distal tube end, such that when said catheter is fully inserted into the bladder via the urethra, said distal sealing means is located within the urethra and forms a seal therewith. 4. A catheter as claimed in claim 1 or claim 2, wherein said at least one irrigation conduit port is proximal to said at least one opening and distal to said proximal sealing means such that when said catheter is fully inserted into the bladder via the urethra, said irrigation conduit port is located within the urethra. 5. A catheter as claimed in claim 3, wherein said at least one irrigation conduit port is on, within or proximal to said distal sealing means and distal to said proximal sealing means such that when said catheter is fully inserted into the bladder via the urethra, said irrigation conduit port is located within the urethra. 6. A catheter as claimed in any one of claims 1 to 5, wherein said at least one drain port is distal to said proximal sealing means such that when said catheter is fully inserted into the bladder via the urethra, said drain port is located within the urethra. 7. A catheter as claimed in any one of claims 1 to 6, wherein said at least one drain port is located proximally with respect to said at least one irrigation conduit port. 8. A catheter as claimed in any one of claims 1 to 7, wherein said at least one drain port is adjacent and distal to said proximal sealing means. 9. A catheter as claimed in any one of claims 1 to 6, wherein said at least one drain port is located distally with respect to said at least one irrigation conduit port. 10. A catheter as claimed in any one of claims 1 to 9, wherein said proximal sealing means comprises proximal spacing means on said outer surface of said tube, wherein said proximal spacing means comprises a diameter slightly larger than that of the urethra inner surface such as to allow said tube to be reversibly inserted within the urethra and to enable a seal to be formed between the urethra inner surface and the said proximal spacing means. 11. A catheter as claimed in claim 10, wherein said proximal spacing means comprises a suitably dimensioned proximal ring. 12. A catheter as claimed in any one of claims 3 to 11, wherein said distal sealing means comprises distal spacing means on said outer surface of said tube, wherein said distal spacing means comprises a diameter slightly larger than that of the urethra inner surface such as to allow said tube to be reversibly inserted within the urethra and to enable a seal to be formed between the urethra inner surface and the said distal spacing means. 13. A catheter as claimed in claim 12, wherein said proximal spacing means comprises a suitably dimensioned distal ring. 14. A catheter as claimed in any one of claims 1 to 9, wherein said proximal sealing means comprises inflatable proximal balloon means on said outer surface of said tube, wherein said at least one irrigation enabling conduit further comprises at least one first inflation port in fluid communication with the interior of said proximal balloon means for enabling inflation of said proximal balloon means, and wherein said proximal balloon means is capable of being inflated to a diameter at least slightly larger than that of the urethra inner surface such as to enable a seal to be formed between the urethra inner surface and the said proximal balloon means, and wherein said proximal balloon means have a reduced diameter when deflated such as to enable said tube to be reversiblv inserted within the urethra. 15. A catheter as claimed in any one of claims 3 to 9 or 14, wherein said distal sealing means comprises inflatable distal balloon means on said outer surface of said tube, wherein said at least one irrigation enabling conduit further comprises at least one third inflation port in fluid communication with the interior of said distal balloon means for enabling inflation of said distal balloon means, and wherein said distal balloon means is capable of being inflated to a diameter at least slightly larger than that of the urethra inner surface such as to enable a seal to be formed between the urethra inner surface and the said distal balloon means, and wherein said distal balloon means have a reduced diameter when deflated such as to enable said tube to be reversibly inserted within the urethra. 16. A catheter as claimed in claim 15, wherein said at least one irrigation conduit port is said third inflation port, and said distal balloon means further comprises at least one opening thereon for providing fluid communication between the interior of said distal balloon means and the exterior of said tube between said proximal balloon means and said distal balloon means. 17. A catheter as claimed in claim 15, wherein said at least one irrigation conduit port comprises at least one opening on said outer surface proximal to said distal balloon means providing fluid communication between the said at least one irrigation enabling conduit and the exterior of said tube between said proximal balloon means and said distal balloon means. 18. A catheter as claimed in claim 17, wherein said at least one irrigation enabling conduit further comprises at least one first delay means comprising a one-way valve means distal to said first inflation port, and biased to open at a predetermined irrigation fluid pressure greater than that required to inflate at least said proximal balloon means. 19. A catheter as claimed in claim 18, wherein said one-way valve comprises a resilient flap valve. 20. A catheter as claimed in claim 19, wherein said flap valve is located on said at least one irrigation conduit port. 21. A catheter as claimed in any one of claims 17 to 20, wherein said at least one irrigation enabling conduit further comprises at least one second delay means, wherein said second delay means comprises a drainage port on said at least one irrigation enabling conduit for providing fluid communication with said drain lumen, said drainage port having a sufficiently small flow area such that irrigation fluid in said at least one irrigation enabling conduit may continuously drain into said drain lumen at a predetermined flow rate, said predetermined flow rate being substantially lower than the irrigation fluid flow rate through said at least one irrigation enabling conduit during irrigation. 22. A catheter as claimed in any one of claims 1 to 21, wherein at least a portion of said outer surface disposed between said irrigation conduit port and said drain port comprises at least one primary groove extending therebetween. 23. A catheter as claimed in claim 22, wherein said at least one primary groove is arranged longitudinally along said elongated tube. 24. A catheter as claimed in any one of claims 22 or 23, wherein at least one said primary groove is arranged helically around said elongated tube. 25. A catheter as claimed in any one of claims 22 to 24, wherein at least a portion of said external surface disposed between said irrigation conduit port and said drain port comprises a plurality of said primary grooves and further comprises at least one secondary groove interconnecting at least one adjacent pair of said primary grooves. 26. A catheter as claimed in claim 25, wherein said at least one secondary groove is arranged circumferentially along said elongated tube. 27. A catheter as claimed in any one of claims 25 or 26, wherein at least one said secondary groove is arranged helically around said elongated tube. 28. A catheter as claimed in any preceding claim wherein said first external fluid source comprises a suitable irrigation fluid. 29. A catheter as claimed in claim 28, wherein said irrigation fluid is a suitable saline solution or chlorhexidine or gluconate or suitable antiseptic solution. 30. A catheter as claimed in any one of claims 1-29, wherein at least part of said at least one irrigation enabling conduit is located within the wall of said elongated tube, intermediate between said inner drain lumen and said outer surface. 31. A catheter as claimed in any one of claims 2 to 30, wherein at least part of said inflation enabling conduit is located within the wall of said elongated tube, intermediate between said inner drain lumen and said outer surface. 32 A catheter as claimed in any one of claims 1 to 31, wherein said elongated tube is made from a medically-compatible resilient material including latex and silicon. 33. A catheter as claimed in any one of claims 1 to 32, wherein said proximal irrigation conduit end comprises a one-way valve to prevent back flow or leakage of fluid therefrom. 34. A catheter as claimed in any one of claims 1 to 33, wherein said proximal tube end is connected to a suitable fluid collection reservoir. 35. A catheter as claimed in claim 34, wherein said fluid collection reservoir is disposable. 36. A catheter as claimed in any preceding claim, wherein said first external fluid source comprises a suitable syringe containing a volume of irrigation fluid. 37. A catheter as claimed in claim 36, wherein said syringe is disposable. 38. A catheter as claimed in any one of claims 1 to 37, wherein said first distance is between 13 cm and 18 cm. 39. A catheter as claimed in any one of claims 1 to 38, wherein said first distance is approximately 16 cm. 40. A catheter as claimed in any one of claims 3 to 39, wherein said second distance is between 4 cm and 7 cm. 41. A catheter as claimed in any one of claims 3 to 40, wherein said second distance is approximately 5 cm. 42. A method for irrigating the urethra, comprising the steps of:- (a) providing a catheter comprising:- an elongated tube insertable into the urethra and having an outer surface, an inner drain lumen, a proximal tube end connectable to a suitable fluid collection reservoir, and a distal tube end insertable into a bladder via the urethra; at least one opening on said outer surface adjacent to said distal tube end providing fluid communication between said drain lumen and the exterior of said elongated tube; suitable proximal sealing means capable of allowing said tube to be reversibly inserted within the urethra and capable of forming a seal with the urethra inner surface, and disposed on said tube at a first distance from and proximal to said distal tube end such that when said catheter is fully inserted into the bladder via the urethra, said proximal sealing means is located within the urethra and forms a seal therewith; at least one irrigation enabling conduit extending along at least a portion of the length of said tube for enabling irrigation of exterior of said elongated tube, said at least one irrigation enabling conduit comprising:- at least one irrigation conduit port in direct or indirect fluid communication with the exterior of the tube, a proximal irrigation conduit end connectable to a first external fluid source and at least one drain port providing fluid communication between the exterior of said elongated tube and said drain lumen; wherein said proximal sealing means comprises inflatable proximal balloon means on said outer surface of said tube, wherein said at least one irrigation enabling conduit further comprises at least one first inflation port in fluid communication with the interior of said proximal balloon means for enabling inflation of said proximal balloon means, and wherein said proximal balloon means is capable of being inflated to a diameter at least slightly larger than that of the urethra inner surface such as to enable a seal to be formed between the urethra inner surface and the said proximal balloon means, and wherein said proximal balloon means have a reduced diameter when deflated such as to enable said tube to be reversibly inserted within the urethra; (b) inserting said catheter into the bladder via the urethra such that said inflatable proximal balloon means is located in the urethra; (c) connecting said proximal irrigation conduit end to said first external fluid source; (d) providing irrigation fluid from said first external fluid source to said irrigation enabling conduit whereby said proximal balloon means is inflated with irrigating fluid to a size sufficiently large to form a seal with the urethra inner surface, and irrigation fluid is delivered through said irrigation conduit port to at least a portion of the urethra irmer surface corresponding to a portion of said elongated tube intermediate between said irrigation conduit port and said drain port, and wherein said delivered irrigation fluid is drained via said drain port. (e) terminating flow of irrigation fluid to said irrigation enabling conduit, whereby flow of irrigation fluid through said irrigation conduit port is terminated, and wherein said proximal balloon means is deflated. 43. A method for irrigating the urethra as claimed in claim 42, wherein the said catheter further comprises :- distal sealing means comprising inflatable distal balloon means on said outer surface of said tube, wherein said at least one irrigation enabling conduit further comprises at least one third inflation port in fluid communication with the interior of said distal balloon means for enabling inflation of said distal balloon means, and wherein said distal balloon means is capable of being inflated to a diameter at least slightly larger than that of the urethra inner surface such as to enable a seal to be formed between the urethra inner surface and the said distal balloon means, and wherein said distal balloon means have a reduced diameter when deflated such as to enable said tube to be reversibly inserted within the urethra, and wherein step (d) further comprises:- inflating said distal balloon means with irrigating fluid to a size sufficiently large to form a seal with the urethra inner surface. 44. A method for irrigating the urethra, comprising the steps of:- (a) providing a catheter comprising:- an elongated tube insertable into the urethra and having an outer surface, an inner drain lumen, a proximal tube end connectable to a suitable fluid collection reservoir, and a distal tube end insertable into a bladder via the urethra; at least one opening on said outer surface adjacent to said distal tube end providing fluid communication between said drain lumen and the exterior of said elongated tube; suitable proximal sealing means capable of allowing said tube to be reversibly inserted within the urethra and capable of forming a seal with the urethra inner surface, and disposed on said tube at a first distance from and proximal to said distal tube end such that when said catheter is fully inserted into the bladder via the urethra, said proximal sealing means is located within the urethra and forms a seal therewith; at least one irrigation enabling conduit extending along at least a portion of the length of said tube for enabling irrigation of exterior of said elongated tube, said at least one irrigation enabling conduit comprising:- at least one irrigation conduit port in direct or indirect fluid communication with the exterior of the tube, a proximal irrigation conduit end connectable to a first external fluid source and at least one drain port providing fluid communication between the exterior of said elongated tube and said drain lumen; wherein said proximal sealing means comprises proximal spacing means on said outer surface of said tube, wherein said proximal spacing means comprises a diameter slightly larger than that of the urethra inner surface such as to allow said tube to be reversibly inserted within the urethra and to enable a seal to be formed between the urethra inner surface and the said proximal spacing means; (b) inserting said catheter into the bladder via the urethra such that said inflatable proximal balloon means is located in the urethra; (c) connecting said proximal irrigation conduit end to said first external fluid source; (d) providing irrigation fluid from said first external fluid source to said irrigation enabling conduit whereby irrigation fluid is delivered through said irrigation conduit port to at least a portion of the urethra inner surface corresponding to a portion of said elongated tube intermediate between said irrigation conduit port and said drain port, and wherein said delivered irrigation fluid is drained via said drain port. (e) terminating flow of irrigation fluid to said irrigation enabling conduit, whereby flow of irrigation fluid through said irrigation conduit port is terminated, and wherein said proximal balloon means is deflated. 45. A method for irrigating the urethra as claimed in claim 44, wherein the said catheter further comprises:- distal sealing means comprising distal spacing means on said outer surface of said tube, wherein said distal spacing means comprises a diameter slightly larger than that of the urethra inner surface such as to allow said tube to be reversibly inserted within the urethra and to enable a seal to be formed between the urethra inner surface and the said distal spacing means. 46. A method for irrigating the urethra as claimed in claims 42 or 43, wherein the said irrigation enabling conduit further comprises first delay means for delaying flow of irrigation fluid through said irrigation conduit port until said proximal balloon means are inflated by said irrigation fluid, second delay means for delaying deflation of said proximal balloon means until flow of irrigation fluid through said irrigation conduit port is terminated; and wherein in step (d): said first delay means delay delivery of irrigation fluid through said irrigation conduit port until said proximal balloon means are inflated as hereinbefore defined; and in step (e): said second delay means delay deflation of said proximal balloon means until flow of irrigation fluid through said irrigation conduit port is terminated. 47. The method as claimed in any one of claims 42 to 46, further comprising:- (f) connecting said proximal tube end to said fluid collection reservoir. 48. The method as claimed in any one of claims 42 to 47, wherein said catheter further comprises :- inflatable bladder balloon means adjacent and proximal to said distal tube end such that when said catheter is fully inserted into the bladder via the urethra, said bladder balloon means is capable of inflation within the bladder to a size sufficiently large to substantially prevent removal of said catheter from the bladder; at least one inflation enabling conduit extending along at least a portion of the length of said elongated tube and having at least one second inflation port in fluid communication with the interior of said bladder balloon means and a proximal inflation conduit end connectable to a second external fluid source for enabling inflation of said bladder balloon means, wherein said proximal inflation conduit end comprises a one-way valve to prevent back flow or leakage of fluid therefrom; and wherein step (b) further comprises inserting said catheter into the bladder via the urethra, such that the said bladder balloon means is located within the bladder, connecting said proximal inflation conduit end to said second external fluid source, providing fluid from said second external fluid source to said inflation enabling conduit whereby to inflate said bladder balloon means to a size sufficiently large to substantially prevent removal of said catheter from the bladder, and pulling said catheter in a proximal direction until said inflated bladder balloon means is seated against the bladder opening to the urethra. 49. The method as claimed in any one of claims 42 to 48, further comprising repeating steps (d) and (e) a plurality of times. 50. The method as claimed in any one of claims 48 to 49, further comprising deflating said bladder balloon means and removing said catheter from said bladder and urethra.

Inventors: BAB ITAI, PORAT GAD, BAB, ITAI, PORAT, GAD
Applicants: BAB ITAI, NOVADENT LTD, PORAT GAD, BAB, ITAI, NOVADENT LTD., PORAT, GAD
Application year: 1998
Main classification: A61M3
IPC codes: A61M3, A61M25