METHOD AND DEVICE FOR THE TRANS-ANAL DRAINAGE OF STOOL FROM THE RECTUM OF A PATIENT AND/OR FOR THE TRANS-ANAL APPLICATION OF INFLOWING LIQUID THROUGH A CATHETER-LIKE ELEMENT

Abstract

The invention relates to a method for leak-minimized emptying of stool from the rectum of a patient and/or for providing leak-minimized access to the rectum for the infusion of liquid substances, by means of a shaft body, which is introduced into the bowel via the anus and is able to elastically fold or invaginate and elastically erect, and whereby the shaft is provided with a dumbbell- or mushroom-shaped balloon body, which is reaching form the rectal portion of the balloon into or through the anal canal. The invention is characterized by a special design and a special choice of materials for the shaft body and the balloon envelope, allowing for a continuous, dynamic trans-anal seal, which is communicating and synchronized with the motility of the anal sphincter and is spontaneously adapting to body movements of the patient, and which is in particular allowing for mobilization of patients from a supine to a sitting or standing patient position or to allow patients for walking, while stool is in a flowable, liquid state or while an infusion of liquid to the rectum is performed.

Claims

1. A method for a leak-minimized or leak-free transanal drainage of stool from the rectum of a patient and/or for a leak-minimized or leak-free transanal administration of inflowing fluid through a catheter-like element, the method comprising the following steps: providing a catheter device comprising: a catheter shaft (6) with a distal end and a longitudinal axis which is surrounded by an outer jacket surface encompassing an inner lumen, which catheter shaft (6) is pre-formed from an elastic material into a defined shape or profile with a pre-shaped cross-section, so that the catheter shaft (6) has elastic deforming and elastic erecting properties at least in its longitudinal axial direction, and an inflatable balloon which is produced from a thin-walled soft film material of limited elastic deformability and is preformed during production to comprise: at least a distal balloon section having a first tubular radius, which is intended to be placed intrarectally, at least a proximal balloon section proximally adjacent to the distal balloon section, which is intended to be placed transanally and has a second tubular radius, wherein the second tubular radius is smaller than the first tubular radius, and wherein, a first balloon end at the distal end of the distal balloon section, and a second balloon end at the proximal end of the proximal balloon section, wherein these two balloon ends taper and are fixed at an axial distance from each other on the jacket surface of the shaft body (6), inserting of the device into the patient through the anal canal, placement of the shaft body (6) in the anal canal and rectum of the patient, wherein, unless the distal end of the shaft body (6) encounters a retarding counteraction, the shaft body (6) remains in its pre-formed, axially straightened shape or profile, while, if the distal end of the shaft body (6) encounters a retarding counteraction, then, due to the elastic deforming and the elastic erecting properties of the balloon carrying shaft body (6), the shaft body (6) is buckling into a single or multiple axial folding and can elastically erect from such an axially deformed, buckled state to the straightened pre-formed state, when the retarding counteraction ends, inflating the balloon with a filling medium only to a flaccid, tensionless state, wherein the device is performing a self-adapting, trans-anal seal, corresponding dynamically with pressure changes inside the abdomen and the rectum of the patient and spontaneously adapting to body movements and to changes of body position, allowing for contamination-minimized spontaneous movement in supine position of the patient or for mobilization of the patient from a supine body position to a sitting or standing position.

2. The method as in claim 1, characterized by a sealing performance of the proximal balloon section, or of a trans-anal segment (3a) of the proximal balloon section, within the anal canal, which is continuously adapting to the motility of the anal sphincter and to rectal pressure changes, wherein actual intra-rectal forces inside the rectal cavity are taken up by the intrarectally placed, distal balloon section, and the thus resulting filling pressure of the medium inside the balloon is keeping the envelope of the proximal balloon section or of a trans-anal segment of the proximal balloon section continuously pressed to the mucosa of the anal canal, thereby providing a seal, continuously corresponding to the functional state of the anal sphincter and synchronized with pressure changes inside the rectum and the abdomen of the patient.

3. The method according to claim 1, wherein the elastic deforming and erecting properties of the balloon carrying shaft body provide a self-adapting, dynamic folding, invagination or flattening of the shaft body inside the anal canal, allowing for a continuous adaptation of the shaft body diameter to the actual opening diameter provided by the anal sphincter, thereby minimizing the magnitude of a permanent opening or dilation of the anus, caused by the trans-anally positioned device, and thereby minimizing a foreign body sensation of the patient, especially when performing larger grade movements of the body and when moving freely.

4. The method as in claim 1, wherein the proximal balloon section, or a trans-anal segment (3a) of the proximal balloon section, when positioned inside the patient in a transanal position, radially flattens, collapses, infolds or invaginates at a normal sphincter tone, and gradually returns to its radially expanded, pre-shaped cross-section when the tone of the anal sphincter is lowering and the anal canal begins to open up, whereby the force that is erecting the proximal balloon section or the trans-anal segment (3a) of the proximal balloon section into the anal canal is equivalent to and synchronous with the force, that is acting on the outside of the distal balloon section, which is placed inside the rectal cavity of the patient.

5. A method according to claim 1, wherein the balloon is only fixed to the shaft body (6) of the catheter at its two balloon ends.

6. The method as in claim 1, wherein the balloon is preformed, during its molding or manufacturing, to its full shape and dimension, required to perform a combined rectally retaining and transanally sealing function, or is preformd or molded beyond that full dimension to a residual dimension.

7. The method as in claim 1, wherein the proximal balloon section, or a trans-anal segment (3a) of the proximal balloon section, is made with a particularly low wall thickness, allowing for an enhanced sealing performance of the balloon within the anal canal.

8. The method according to claim 1, wherein the patient is unsedated or only partially sedated and vigilant, performing spontaneous movements of the body stem and the extremities, whereby the patient can be in a supine body position, or wherein the patient is being mobilized from a supine to a sitting or standing position, or wherein the patient is walking.

9. The method according to claim 1, wherein the feces of the patient are modified to a liquid or flowable state by an orally or intravenously administered stool modification scheme, for example by orally administered agents as e.g. polyethylene glycol or lactulose based agents, keeping the feces continuously in a flowable, drainable state.

10. The method according to claim 1, wherein, in the presence of a normal sphincter muscle tone of the patient bearing at resting tone against the shaft body (6) from the outside, it deforms radially in the form of a radial collapse, infolding or invagination of the shaft jacket, and upon relaxation of the tone of the sphincter muscle of the patient spontaneously straightens elastically again and releases the drainage lumen of the shaft body.

11. The method as in claim 1, wherein the elastic deforming and erecting properties of the envelope of the balloon carrying shaft body are adjusted so that, when the balloon is freely unfolded outside the body to a balloon filling pressure of 120 mbar or more, the cross-section of the remaining drainage lumen within the shaft tube is reduced with regard to the initial cross-section in the freely unfolded, but pressureless state of the balloon, by at least 10%, preferably by at least 25%, especially by at least 50%, in particular by at least 80%.

12. The method as in claim 1, wherein a balloon pressure-induced reduction of the cross-section of the drainage lumen within the shaft tube takes place either gradually, that is like a continuous, narrowing or collapsing, or abruptly, that is like a toggling between an open condition and a constricted condition, especially an infolded or invaginated condition.

13. The method as in claim 1, wherein the elastic deforming and erecting properties of the balloon carrying shaft tube envelope are adjusted so that, when the balloon is freely unfolded outside the body and pressurized to a balloon filling pressure of up to 5 mbar, the cross-section of the remaining drainage lumen within the shaft tube is reduced with regard to the initial cross-section in the freely unfolded, but pressureless state, by no more than 70%, that is to a residual cross-section of at least 30% of its freely unfolded initial cross-section in pressureless state.

14. The method as in claim 1, wherein the elastic deforming and erecting properties of the balloon carrying shaft tube envelope are adjusted so that, when the balloon is freely unfolded outside the body and pressurized to a balloon filling pressure of up to 10 mbar, the cross-section of the remaining drainage lumen within the shaft tube is reduced with regard to the initial cross-section in the freely unfolded, but pressureless state, by no more than 90%, that is to a residual cross-section of at least 10% of its freely unfolded initial cross-section in pressureless state.

15. The method as in claim 1, wherein the elastic deforming and erecting properties of the balloon carrying shaft tube envelope are adjusted so that, when the balloon is freely unfolded outside the body and pressurized to a balloon filling pressure of up to 25 mbar, the cross-section of the remaining drainage lumen within the shaft tube is reduced with regard to the initial cross-section in the freely unfolded, but pressureless state, to a residual cross-section of no more than 50% of its freely unfolded initial cross-section in pressureless state.

16. The method as in claim 1, wherein the elastic deforming and erecting properties of the balloon carrying shaft tube envelope are adjusted so that, when the balloon is freely unfolded outside the body and pressurized to a balloon filling pressure of up to 45 mbar, the cross-section of the remaining drainage lumen within the shaft tube is reduced with regard to the initial cross-section in the freely unfolded, but pressureless state, to a residual cross-section of no more than 20% of its freely unfolded initial cross-section in pressureless state.

17. The method as in claim 1, wherein the envelope of the balloon carrying shaft segment of the device, when placed inside the patient in transanal position, radially flattens, collapses, infolds or invaginates at a normal sphincter tone, and gradually returns to its preformed cross-section when the tone of the anal sphincter is lowering and the anal canal begins to open up, whereby the force that is elastically erecting the shaft tube envelope is larger than the force that is resting on the outside of the shaft tube, which is exerted by the filling pressure of the filling medium acting inside the balloon.

18. The method as in claim 1, comprising the following steps: a) initially, conducting a lavage-like infusion of a high volume of a liquid, directed to the rectum and the colon of the patient, b) subsequently, conducting a continuous drainage of bowel content.

19. The method as in claim 1, wherein the balloon comprises a mushroom shape with a distal terminal balloon section with a larger tubular radius for intrarectal placement in order to retain or anchor the device, as well as with a proximally adjoining terminal balloon section with a tapered tubular radius for extending the balloon into the anal canal.

20. The method as in claim 19, wherein the trans-anal segment either ends at the level of the outer anal opening, namely the anal rim, or extends extracorporeally beyond the anal rim by 2 to 5 cm, preferably by 2 to 3 cm.

21. The method as in claim 1, wherein the balloon comprises a waisted shape which is formed by two terminal balloon sections with a larger tubular radius, one of which is placed intrarectally, while the other one is placed extrcorporeally, as well as, disposed therebetween and tapered relative thereto, a middle balloon section that has a reduced tubular radius and is placed transanally.

22. The method as in claim 21, wherein the intrarectal balloon section and the extracorporeal balloon section have approximately the same longitudinal cross sections.

23. The method as in claim 1, wherein the balloon is assembled from two or more separate balloon segments.

24. The method as in claim 23, wherein the assembled balloon comprises a trans-anal segment (3a) with a particularly low wall thickness, allowing for an enhanced sealing performance of the balloon within the anal canal.

25. The method as in claim 1, wherein the distal end of the shaft component (6) is extended by a component (6a) with a cone- or olive-shaped outer surface and an open lumen in the center, which projects beyond the distalmost part of the intrarectal balloon component (4) and is extending the distal balloon radius (8).

26. The method as in claim 1, wherein the balloon carrying segment of the shaft component (6) is molded to a corrugated profile (6b) entirely or partially.

27. The method as in claim 1, wherein the shaft component (6) is reinforced by an additional, lumen erecting, mesh-like structure (6c) entirely or partially along the balloon carrying segment.

28. The method as in claim 1, wherein in the presence of a greater axial deflection of the proximal shaft end of the shaft supporting the balloon toward the bowel, the shaft supporting the balloon transitions to the state of single or multiple axial buckling.

29. The method as in claim 28, characterized by a multi-step buffering of a shaft deflection.

30. The method as in claim 1, wherein the shaft body is provided with a sheath.

31. The method as in claim 30, wherein the sheath is in the form of foam or gel-based element or made from a layer of a soft silicone.

32. The method as in claim 30, wherein the sheath, particularly a foam or gel-based element or of a silicone based element, extends beyond the distal end of the catheter, preferably by at least 5 mm, particularly by 10 mm or less.

33. The method as in claim 30, wherein the sheath is segmented and/or has changes in cross section and/or recesses.

34. The method as in claim 30, wherein the sheath is completely or partially surrounded outwardly by the balloon.

35. The method as in claim 30, wherein the sheath is fixed toward the inner face of the balloon, particularly toward the inner face of the intrarectal balloon section.

36. The method as in claim 1, characterized by a folding of the catheter shaft, preferably along predefined circumferential regions, such as, for example, cross-sectional tapers, recesses or the like.

37. A device for a leak-minimized or leak-free transanal drainage of stool from the rectum of a patient and/or for a leak-minimized or leak-free transanal administration of inflowing fluid through a catheter-like element, wherein the device is in the form of a catheter comprising: a catheter shaft (6) with a distal end and a longitudinal axis which is surrounded by an outer jacket surface encompassing an inner lumen, which catheter shaft (6) is pre-formed from an elastic material into a defined shape or profile with a pre-shaped cross-section, so that the catheter shaft (6) has elastic deforming and elastic erecting properties at least in its longitudinal axial direction, and an inflatable balloon which is produced from a thin-walled soft film material of limited elastic deformability and is preformed during production to comprise: at least a distal balloon section having a first tubular radius, which is intended to be placed intrarectally, at least a proximal balloon section proximally adjacent to the distal balloon section, which is intended to be placed transanally and has a second tubular radius, wherein the second tubular radius is smaller than the first tubular radius, and wherein, a first balloon end at the distal end of the distal balloon section, and a second balloon end at the proximal end of the proximal balloon section, wherein these two balloon ends taper and are fixed at an axial distance from each other on the jacket surface of the shaft body (6), wherein the shaft body (6) of the catheter when inserted into the rectum of the patient remains in its its pre-formed, axially straightened shape or profile until the distal end of the shaft body (6) encounters a retarding counteraction, and then, due to the elastic deforming and the elastic erecting properties of the balloon carrying shaft body (6), is buckling into a single or multiple axial folding and can elastically erect from such an axially deformed, buckled state to the straightened pre-formed state, when the retarding counteraction ends, and wherein the balloon when placed inside the return and anus of the patient is performing a self-adapting, trans-anal seal, corresponding dynamically with pressure changes inside the abdomen and the rectum of the patient and spontaneously adapting to body movements and to changes of body position, allowing for contamination-minimized spontaneous movement in supine position of the patient or for mobilization of the patient from a supine body position to a sitting or standing position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0093] FIGS. 1a to 1c show, schematically and by way of example, a waisted balloon envelope, tapered in its middle section to an hourglass or dumbbell shape, unfolded spatially freely and without pressurization.

[0094] FIG. 2 shows an embodiment of the device in which the distal end of the shaft tube, directed toward the bowel, is connected nearly flushly to the distal shaft end of the balloon, and when the balloon envelope is unfolded freely and without pressurization, terminates nearly flush with the frontal radius of the intrarectal segment of the balloon.

[0095] FIG. 2a shows a device with a mushroom-shaped balloon component, comprising an intrarectal segment and a transanal segment.

[0096] FIG. 2b shows a device as described in FIG. 2, whereby the distal end of the shaft tube is extended by a cone-shaped, insertion facilitating element, exceeding the distal radius of the intra-rectal balloon segment.

[0097] FIG. 2c shows a device as described in FIG. 2, whereby the envelope of the balloon carrying segment of the shaft component is molded to a corrugated profile.

[0098] FIG. 2d shows the balloon carrying segment of the shaft component, supplemented by an additional mesh-like structure, modifying the elastic deformation and erection of the shaft tube.

[0099] FIG. 2e shows a particular balloon design, whereby the dumbbell or mushroom shape of the balloon is assembled from two separate balloon segments, integrating a particularly thin-walled balloon envelope in the trans-anal segment of the assembled balloon, enhancing the seal performance of the balloon within the anal canal.

[0100] FIG. 2f shows the trans-anal segment of the device positioned inside the anal canal, consisting of two concentric tube-like structures, picturing the sealing performance of the outer balloon wall, and the stool draining function of the inner shaft tube.

[0101] FIG. 3 shows the embodiment variant described in FIG. 2 with the device placed transanally, in the state of an axial deflection toward the bowel of the shaft tube inside the balloon body mounted on the shaft tube by an amount A, resulting in a corresponding elastic deformation of the forward envelope portions of the intrarectal balloon segment by amount A, thereby limiting the deflection of the shaft.

[0102] FIG. 4 shows the embodiment variants described in FIG. 2 or FIG. 3 with the device placed transanally, in the state of an axial deflection toward the bowel of the shaft tube inside the transanally placed balloon body mounted on the shaft tube by an amount B which cannot be absorbed by elastic deformation of the envelope portions of the intrarectal balloon segment to limit the deflection of the shaft, but instead gives way to single or multiple folding or kinking of the shaft tube over its longitudinal axis, whereas the forward envelope portions of the intrarectal balloon segment are deflected toward the bowel merely by the amount A.

[0103] FIG. 5 shows another embodiment variant of the device in which, with the balloon body unfolded freely and without pressurization, the shaft ends of the balloon body are inverted on both sides by an amount C and in this position are fixed on the shaft tube.

[0104] FIG. 6 shows the embodiment variant in FIG. 5 wherein the shaft tube is deflected axially toward the bowel inside the transanally placed balloon body mounted on the shaft tube by an amount C, under which circumstances the shaft allows itself to displace toward the bowel in free relative movement by an amount C, without the occurrence, described in

[0105] FIG. 3, of the elastic deformation of the envelope portions of the intrarectal balloon segment to limit the movement of the shaft.

[0106] FIG. 7 shows in schematic cross section an embodiment of the device in which the shaft tube supporting the balloon is supplemented by a sheath having a protective and/or elastically lumen-straightening effect.

[0107] FIG. 8 shows in schematic cross section various embodiment variants of a shaft tube sheath corresponding to FIG. 7, with complete and partial segmentation of the jacket to predispose the shaft to kink or buckle axially.

[0108] FIG. 9 shows further embodiment variants of a sheath.

[0109] FIG. 10 is a cross section through the drain body showing the combined dampingly protective and elastically lumen-straightening effect of a sheath of the shaft tube in the presence of radial deformation or infolding of the shaft body.

[0110] FIG. 11 shows a particular embodiment of the device for self-adjusting, axially oriented sealing of the balloon against the inner and outer openings of the anal canal, wherein the balloon shaft ends are inverted on the shaft tube on both sides by an amount D and are fixed on the shaft tube, thereby ensuring that the free, distal end of the shaft still assumes a position inside the intrarectal balloon segment even when the terminal balloon portions of the hourglass- or dumbbell-shaped balloon body maximally approach each other via an axial counter-rolling movement.

[0111] FIG. 12 shows further embodiments of the shaft body supporting the balloon.

[0112] FIG. 1 shows a longitudinal section through a freely unfolded balloon body 2 that has already been shaped to its functional working dimension during production, with its free balloon shaft ends 9 and 10. The forward balloon radius 8 of the intrarectal balloon segment, facing frontally toward the bowel lumen, is indicated as a broken line.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0113] The frontal balloon radius 8 is constructed from the two inflection points 9a and 9b and the two tangents 9c and 9d respectively belonging to these points. On this basis, a circle is constructed that intersects the two inflection points 9a and 9b and whose tangents (9c, 9d) in these points correspond to those of the inflection points. The apex Y is derived from the intersection point of the circumference of the circle with the axis X of symmetry of the balloon.

[0114] In the following description of the frontal apex of the intrarectal balloon enlargement, the intersection point of the line Z connecting the two inflection points to the axis X of symmetry will be used to simplify the representation of the point on the balloon envelope that ranges the farthest distally.

[0115] The balloon body comprises two spherical or approximately spherical enlargements, one at each end, the distal, intrarectal balloon enlargement 4 being connected via a middle, diametrally tapered or waisted segment 3 to the proximal, preanal enlargement 5. The middle, waisted segment 3 is placed in the anal canal and accordingly takes on the structures of the anus between the terminal balloon enlargements. The middle taper of the balloon ensures, on the one hand, the largely dislocation-proof positioning of the drainage device in the anal canal under the pulling and pushing forces that are exerted axially on the device under typical use conditions, and, on the other hand, permits particularly large-area and therefore efficient sealing of the balloon envelope with respect to the wall or mucosa of the anal canal. The middle segment also serves a protective function, in that continual direct mechanical contact of the structures of the tube shaft with the sensitive tissues of the anal canal is prevented by the protectively acting envelope of the waisted intermediate segment. To achieve good sealing performance, the wall thickness of the balloon envelope in the transanal segment should be approximately 10 to 50 μm, but preferably only 10 to 20 μm. The diameter in the transanal segment 3 should be approximately 15 to 45 mm, preferably 20 to 30 mm. Due to the relatively large diameter of the transanal balloon envelope, radially inwardly directed invaginations of the balloon envelope form as it is placed transanally. The radial invagination of the residual balloon envelope in this section eliminates the need for forceful expansion of the envelope wall to seal the anal canal between the catheter shaft and the wall of the anal canal.

[0116] Complete preforming of the waisted balloon body to the functional working dimension during the production of the balloon eliminates the need for the expansion, under high, non-physiological pressure, of the usually volume-expandable, non-preformed or only partially preformed balloon envelope used with intestinal tubes having conventional anchor balloon elements, and, in contrast hereto, permits balloon filling pressures that are always experienced as low and that have little or no adverse effect on tissue perfusion in the tissues adjacent the balloon.

[0117] The balloon component is preferably made from a very thin-walled, only slightly volume-expandable and overall dimensionally stable material with little tendency toward herniation, which material, although exhibiting the properties of a physiologically compatible soft film in the preferred wall thickness range of a few micrometers, nevertheless does not deform uncontrolledly with increasing filling pressure, and also limits that tendency of the balloon to slip in response to tension exerted on the catheter shaft from the outside which must be expected with highly volume-expandable materials, such as, for example, natural rubber or silicone, and thus enables the drainage device to provide a good transanal anchoring effect that is markedly superior to that of volume-expandable materials. Micro thin-walled balloon films made of, for example, polyurethanes with Shore hardnesses of 70 A to 95 A, preferably 85 A to 90 A, provide an envelope stability as called for by the invention. The wall thickness of the balloon envelope in the region of its terminal enlargements should be approximately 7 to 45 μm, preferably 10 to 20 μm.

[0118] Suitably thin-walled balloon films are preferably formed using materials of little or no volume-expandability, such as, for example, polyurethane (PUR), for example of the specification Pellethane 2363 80 A or 90 A, Dow Chemical Corp., or alternatively Elastollan of grades 1180A to 1195A, BASF AG. Alternatively, PVC or blends of PUR and PVC, coextruded

[0119] PUR/PVC materials, coextruded PUR/Polyamide materials, coextruded PUR/Pebax materials, Pebax, or Polyethylenes, allowing for elastic deformation properties comparable to or even lower than those of polyurethane can be used.

[0120] Such thin-walled balloon films formed into complex shape can preferably be produced by hot molding from previously extruded raw tubing material, a method that gives the formed balloon films unusual strength due to the polymer orientation that can be obtained in this way. Balloon films according to the invention can also be formed directly from the extruded, still soft, amorphous tube molding compound (in-line molding).

[0121] Dipping processes and corresponding production from liquid PVC or PUR materials may also be contemplated. The welding together of single layers of film to form balloon bodies is also conceivable.

[0122] The filling of the balloon is preferably effected with a filling volume calculated to be less than the volume of the balloon with the balloon envelope mounted on the shaft and unfolded without pressurization. Such incomplete filling ensures that, once filled, the balloon envelope will not progress immediately to the state of being fully expanded on all sides, thus attaining filling pressure values in excess of the intrarectally and transanally acting physiological forces. In the state of incomplete filling of the balloon envelope, the sum of the forces acting intrarectally, transanally and preanally on the balloon have the effect of a force acting transmurally and uniformly on all sides on the tissue exposed to the balloon. Proper partial filling is preferably ensured by the use of a filling syringe provided with suitable volume markings and supplied with the product.

[0123] FIG. 2 shows a longitudinal section through an intestinal tube 1 according to the invention, comprising an hourglass- or dumbbell-shaped balloon element 2 mounted at the distal end of a shaft tube 6. The balloon element has spherical- or discoid enlargements at its ends. Disposed in the middle region between the enlargements is a tapered, for example cylindrically or approximately cylindrically shaped waist-like segment 3. In this embodiment, the distal balloon shaft end 9 is mounted on a shaft tube 6 in such a way that the transition points 9e and 9f where the bottom balloon radius passes over into the cylindrical portion of the balloon shaft terminate flush or nearly flush with the free distal end of the shaft tube 6. The connecting line V between points 9e and 9f will be referred to hereinafter as the forward fixation line and describes the particular mechanically acting fixation points of the distal balloon end on the shaft tube supporting the balloon. In the described embodiment, the free distal end of the shaft tube therefore lies on the forward fixation line V, which in turn is surpassed in a distal direction by the connecting line Z of the inflection points of the balloon shoulder radii, as a result of which the frontal, distally protruding portion of the intrarectal balloon envelope prevents the free end of the shaft from coming into direct contact with portions of the bowel and thus acts as a mechanical buffer.

[0124] In the described embodiment, the fixation of the proximal balloon shaft end 10 on the shaft tube is guided by the state of free unfolding of the balloon envelope, the distal balloon shaft first being connected. The proximal connection is made electively either at rear fixation line H.sub.1 (with the balloon shaft end 10 inverted in a distal direction) or at rear fixation line H.sub.2 (with the balloon shaft end extending outward in a proximal direction). The rear fixation lines are constructed analogously to the forward fixation lines, from the transitions 10 and 10b of the bottom balloon shoulder radii to the balloon shaft and their connecting line.

[0125] FIG. 2a shows a simplified embodiment of the device with a mushroom-shaped, preformed balloon, having only one distal, spherical or discoidal enlargement 4 for intra-rectal positioning and retention of the device, which is proximally extended by a tapered balloon section 3a of relative thereto smaller diameter, preferably having the same diameter as the trans-anal balloon segment described in this disclosure, but having a length, which is matching with the outer opening of the anal canal, or in a preferred embodiment, exceeding the anal rim by 2 to 5 cm, so that the user can control the balloon filling inside the patient's bowel by visual inspection and/or tactile judgement.

[0126] FIG. 2b shows another embodiment of a device according to the present invention, comprising a dumbbell- or mushroom-shaped balloon component, whereby the distal shaft end is extended by a component 6a with cone- or olive-shaped outer surface and an open lumen in the center, which projects beyond the distalmost part of the intrarectal balloon component 4 and is extending the distal balloon radius 8, thereby facilitating the insertion of the device through the anus into the rectum. The insertion aiding component 6a is preferably made from a soft, deformable, e.g. gel- or foam-based material. The frontal radius of component 6a laterally adjacent the tip of the component 6a is preferably large, reducing the likeliness of causing an irritation or a traumatic injury of the bowel wall. In case of a bowel-wards directed dislocation of the device from its regular trans-anal position, a potential bowel injury is prevented by the particular axial buckling performance of the shaft tube component, described as a main feature in the invention.

[0127] FIG. 2c shows a modification of the device according to the present invention as described in FIG. 2, whereby the balloon carrying segment of the shaft component 6 is molded to a corrugated profile 6b. The corrugation of the shaft tube envelope allows for an axial bending of the device by 90 to 180 degrees, keeping the lumen of the tube largely opened and granting an unimpaired drainage performance of the flexed tube component. Compared to a non-profiled tube shaft component, the particular, corrugated profile 6b allows for a reduction of tube wall thickness, while at the same time enhancing the promptness of the elastic axial and radial deformation and erection of the tube.

[0128] The above described elastic bending and deformation properties of the corrugated profile 6b can be realized, for example, by making at least the regarding shaft element from Polyurethane (PUR), especially by use of a material with durometer of 85 A, and/or by designing an inner diameter from 15 mm to 20 mm, especially of about 17 mm, and/or a tube wall thickness of 0.5 to 0.7 mm, and/or a corrugation amplitude of 2.5 to 3.0 mm, and/or a wave-length of the corrugation of 2.0 to 3.0 mm. In particular, by one or more of these design features, the appropriate shaft collapse at normal sphincter tone and the elastic erection of the shaft to its shaped profile, withstanding a certain balloon filling pressure, resting on the outside of the shaft tubing, can be achieved.

[0129] Such corrugation 6b can be molded into the tube profile, either over the entire length of the balloon carrying shaft tube segment or only in fragmented portions of it.

[0130] FIG. 2d shows the balloon carrying segment of the shaft component 6, reinforced by an additional, lumen erecting, mesh-like structure 6c. Said mesh 6c can be made from elastic material, as e.g. Polyurethane (PUR). The mesh 6c is structurally connected to the stool draining tube layer, either by bonding or by extrusion or molding it onto or into the tube or shaft surface during an extrusion or molding process adjusted accordingly.

[0131] FIG. 2e shows a balloon design 2a, whereby the balloon is assembled from two or more separate balloon segments. The assembled balloon comprises a trans-anal segment 3a, that is having a particularly low wall thickness, allowing for an enhanced sealing performance of the balloon within the anal canal.

[0132] When molding the balloon components from pre-extruded PUR tubing in a standard hot-molding procedure, the balloon segments of lower diameter typically have a higher thickness than the balloon portions of a relatively larger diameter.

[0133] In the invented device, the sealing performance is enhanced by the continuous, tightly sealing contact of the tapered trans-anal balloon segment to the mucosa of the anal canal. Therefore, a minimized thickness of the trans-anal balloon segment is of advantage. In order to provide the herein required balloon shapes, the trans-anal segment is molded as a separate component and in a second step connected to the other enlarged sections.

[0134] Furthermore, different parts of the assembled balloon can be made of materials of different durometers, e.g. making the tapered, middle or proximal balloon segment from a higher durometer PUR material of Shore 55D to 65D and minimizing wall thickness to less than 10 μm, whereby the trans-anal section combines optimized sealing with enhanced shape stability, preventing a deformation of the dumbbell or mushroom shape at an increased balloon filling pressure. In contrast, the intra-rectal balloon section 4a of the assembled balloon 2a can be made of a material, that is of lesser compliance than the adjoining balloon section 3b, allowing for a more compliant balloon expansion at increased balloon filling pressure.

[0135] The separately molded segments are connected to each other, e.g. by an overlapping seam 3d, where the balloon ends are e.g. welded or bonded together tightly.

[0136] FIG. 2f pictures the tapered, middle or proximal section of the balloon in situ, positioned inside the anal canal AK. The normal tone of the anal sphincter muscle causes the inner one of the two concentric balloon and/or tubing structures, namely the stool draining shaft tubing 6, to collapse from its preformed, preferably circular profile to an infolded profile 6d, preventing a permanent opening and dilation of the anal sphincter. At the same time, the outer structure, the trans-anal balloon segment 3, is kept in a seal effecting contact to the anal mucosa, whereby the force that is pressing the balloon film to the inner surface of the anal canal is taken up inside the rectum, following the actual rectal forces dynamically. The residual wall portions of the trans-anal balloon segment are invaginating into folds 3e, radially directed towards the center of the anal canal.

[0137] Once the anal tone is lowering and/or the anal canal is opening, the inner shaft tube erects and opens its lumen. Thereby, the self-erecting elastic force is exceeding the force exerted onto the shaft by the pressurized balloon filling. The shaft tube shall not collapse at balloon filling pressures of 25 mbar to more than 50% of its largest cross-section.

[0138] On the other hand, a balloon filling pressure of 50 mbar or more shall result in a substantial radial collapse, with a reduction to a residual cross-section of the drainage lumen of less than 80% of the initial cross-section of the drainage lumen in the completely unfolded, but pressureless state of the balloon.

[0139] A balloon filling pressure of 60 mbar or more shall result in a substantial radial collapse, with a reduction to a residual cross-section of the drainage lumen of less than 90% of the initial cross-section of the drainage lumen in the completely unfolded, but pressureless state of the balloon.

[0140] Finally, a balloon filling pressure of 65 mbar or more shall result in a substantial radial collapse, with a reduction to a residual cross-section of the drainage lumen of less than 95% of the initial cross-section of the drainage lumen in the completely unfolded, but pressureless state of the balloon.

[0141] FIG. 3 shows the device described in FIG. 2 in transanal placement in the anal canal AK, in the state of axially oriented deflection into the intestinal lumen DL of the catheter shaft 6 inside the balloon mounted on the shaft tube, by an amount A in response to the force F.sub.1 imposed on the shaft in the shaft longitudinal axis.

[0142] The advancement of the distal shaft tube end 7 into the intestinal lumen DL is limited by the elastic deformation of the frontal balloon wall portions of the intrarectal balloon segment 4, which deformation counteracts the free deflection of the shaft. In the implementation of the device and the acting force F.sub.1 depicted here, the distal shaft tube end and thus the forward fixation line V do not pass into the intestinal lumen beyond a maximum deflection distance A predefined by the elastic deformation properties of the intrarectal balloon envelope and thus constituting a limit.

[0143] The proximal reference point for the determination of the deflection distance A is the rear fixation line H (H1 or alternatively H2) in the unloaded state in the absence of an imposed force K.sub.1.

[0144] In the inventive shaping of, dimensioning of, and choice of material for the balloon envelope, the maximum possible deflection distance A of the distal end of the tube shaft should approximately correspond to the apex S of a radius constructed over the largest diameter GD of the intrarectal balloon enlargement 4. The largest diameter GD in this case refers to the respective diameter with the balloon in the freely unfolded, unpressurized state.

[0145] To ensure suitable limitation of the deformation of the balloon envelope directed relatively toward the bowel, the balloon body 2 is preferably made from a material of low elastic deformability, a choice that is especially important for the preferred thin-walled implementation of the balloon envelope in the low micrometer range; typically volume-expandable materials, such as, for example, natural rubber or silicone, are largely ruled out for the production of the balloon.

[0146] FIG. 4 shows the device described in FIG. 2 and FIG. 3 in the state of an axial deflection of the catheter shaft toward the bowel inside a transanally placed balloon in the presence of a force F.sub.2 acting on the catheter shaft from a proximal direction that exceeds the force F.sub.1 described in FIG. 3.

[0147] When a certain critical force F.sub.kink is exceeded, single or even multiple axial kinking (KS) of the shaft tube 6 occurs. At the instant of the kinking or buckling of the shaft tube, the axially acting resistance of the shaft tube to the force K.sub.2 acting on the shaft from a proximal direction abruptly gives way and the shaft tube deflects farther to as much as the full distance B, the force action exerted by the shaft tube on the frontal portions of the intrarectal balloon segment being nearly constant.

[0148] However, the maximum deflection of the forward fixation line V by amount A is not exceeded during the deflection of the shaft by amount B, a fact that is decisive for the inventive safe fixation of the free, potentially perforating shaft end 7.

[0149] The proximal reference point for determining the deflection distance B is, in turn, the rear fixation line H (H1 or alternatively H2) in the unloaded state in the absence of an imposed force K2.

[0150] In like manner, conversely, a force exerted on the shaft tube from distally to proximally initially results in a proximally directed deflection of the shaft body inside the transanally placed balloon and a corresponding deformation of the proximal balloon portions of the preanal balloon segment 5. With increasing force action and the excedence of a critical force, even in this deflection case the shaft tube 6 passes into the previously described buckled state KS and allows a further deflection of the shaft in a proximal direction under a then constant force acting on the shaft.

[0151] Such a kinking or buckling behavior of the device is relevant primarily when portions of the bowel are resting distally on the frontal portions of the balloon or when a forced deflection of the shaft tube into the bowel completely dislocates the device from its transanal fixation and the intrarectal portions of the device impinge on the bowel wall.

[0152] In the respective embodiments of the present invention, the critical force K.sub.kink should preferably be reached at a weight force imposed axially on the shaft of approximately 150 to 1000 grams, particularly preferably, however, at forces in the range of 200 to 500 grams.

[0153] As FIG. 5 shows, the invention also proposes, in addition to the specific consideration of larger deflections of the shaft tube inside the transanally placed balloon, embodiments in which the forward and rear fixation lines V and H of the balloon shaft ends are offset toward each other (inverted) on the shaft tube by a defined amount C, whereby smaller axial deflections of the catheter shaft for the distance C can be buffered by an axial relative movement between the balloon and the shaft without the occurrence of deformation of the envelope of the intrarectal balloon segment or distal displacement of the forward fixation line V beyond balloon radius 8.

[0154] Farther-reaching deflections of the shaft that exceed the buffering distance C permitted by the inversion of the fixing ends are dampingly absorbed, in an analogous manner to the embodiment of FIG. 3, by elastic expansion of the envelope.

[0155] With a shaft outer diameter of approximately 12 mm, the inwardly directed offset VF of the fixation lines V and H should preferably be approximately 10 to 12 mm. With a shaft outer diameter measuring 15 mm, the offset VF should correspondingly be equal to 12 to 16 mm. The reference point for the offset is the respective connecting line Z between the inflection points of the radii where they transition to the balloon shoulders of the freely unfolded, unpressurized balloon.

[0156] FIG. 6 shows the device described in FIG. 5 in the transanally placed state, in which the shaft tube supporting the balloon can be displaced toward the bowel inside the transanally placed balloon relatively freely by an amount C without accompanying elastic deformation of the envelope portions of the intrarectal balloon segment to limit the movement of the shaft.

[0157] FIG. 7 represents particular embodiments of the device in which the shaft tube 6 supporting the balloon 2 is supplemented by a sheath 16 that is protective and/or has an elastically lumen-straightening effect. The figure shows a longitudinal section through an intestinal tube 1 having a continuous sheath that is disposed on the shaft element 6 and consists of preferably foam-like, elastically deformable and spontaneously self-straightening materials.

[0158] The sheath 16 preferably extends beyond the distal end of the shaft tube 6 (protrusion US) and thus provides additional buffering protection for the bowel wall against the free end 7 of the shaft tube. The foam bodies in this case protrude past the distal end of the shaft tube by preferably 3 to 12 mm, and particularly advantageously by 4 to 8 mm.

[0159] Optionally, the sheath 16 can also extend in a proximal direction to the shaft tube section adjacent the preanal shaft segment.

[0160] According to FIG. 8, this embodiment of the device proposes a segmentation of the sheathing body 16. This is preferably effected inside the intrarectal balloon segment or, alternatively, in the transitional region between that segment and the transanal segment. The sheath body can be disposed on the drainage tube in the form of completely separate and spaced-apart units, e.g. 16a and 16b. Alternatively, a segmentation can be created by pronounced waisting 26 of a continuous jacket structure 16. The segmentation or waisting reduces the kinking stability of the shaft body in the intermediate segment region 23 or the region of the jacket taper 26, and thus preforms the axial kinking of the shaft in a desired shaft section (nominal kinking site). A plurality of such kinking sites can be arranged over the course of the sheathing of the drainage tube 6.

[0161] Given an internal diameter of the shaft tube of approximately 15 mm, the foam-free piece 23 between the foam elements 16a and 16b should preferably have a length of 5 to 15 mm, particularly preferably of 5 to 10 mm.

[0162] According to FIG. 9, the distal foam segment 16a inside the balloon segment 4 can be configured to serve the function of an abutment component, for example in a ball or disk shape. The component provides an additional anchoring effect when the tube is inserted into the rectum. The abutment component thus prevents the tube from accidentally slipping out of the rectum before the balloon is filled. A foam segment 16b of corresponding shape, disposed on the shaft tube 6 inside the preanal segment 5, can serve as a guide mark for determining the correct insertion depth of the device in the anus.

[0163] A correspondingly shaped distal segment 16a can also have a buttressing effect on the shaft tube and limit the lateral tilting of the shaft toward the bowel wall. This effect is the more reliable, the farther distally toward the shaft opening 7 the abutment body is disposed on the shaft. The foam body preferably consists of a polyurethane foam, which, in turn, preferably has viscoelastic deformation and straightening properties.

[0164] The distal and proximal foam segments can also be continuously joined by a tapered intermediate segment, the foam body 16 thus forming a unit in the shape of an hourglass or dumbbell.

[0165] For improved protection against axial deflections of the distal end of the tube into the bowel, there can be a structural connection 17 of the distal balloon envelope to the distal-facing surface of the inwardly disposed foam body 16a or of the corresponding surface of the above-described dumbbell-shaped foam body, as the case may be. The connection 17 can be produced, for example, by areal gluing.

[0166] Analogously to the embodiment of FIG. 7, here again, the distal segment 16a or the distal end of the sheath 16 can extend beyond the distal free end 7 of the shaft tube by a defined projecting offset US.

[0167] FIG. 10 shows in cross section the radial invagination 22 of the wall of the shaft tube 6, and the corresponding folding of a foam jacket 16, which in this embodiment is mounted on the shaft tube in a continuously fixed manner. Potentially cutting edge formations 23 of the kind that can develop in the apex region of the invagination 23 are cushioned atraumatically softly in their effect on the adjacent tissue.

[0168] Preferably soft, elastically self-straightening polyurethane foams are used to fashion the shaft body. Analogously to the support lent to the axially acting elastic straightening of the deformed shaft tube wall, an elastically acting sheath supports the spontaneous radial straightening of a radially infolded shaft tube wall.

[0169] The foam elements can also be foamed directly onto the supporting tube during the production of the device, thus eliminating the need for areal connection to the supporting underlayer with solvents or glue.

[0170] Combinations of the following materials and properties, as examples, have proven advantageous for the material composite of the shaft body in all the presented embodiments of the device. The shaft tube 16 consists of a polyurethane of Shore hardness 70-90 A and has an internal diameter of approximately 15 mm and a wall thickness of 0.2 to 0.3 mm. The foam jacket 16 has a wall thickness of approximately 1 to 5 mm, preferably 1.5 to 2.5 mm. Its consistency and elasticity correspond to those of the material MS SuperSoft 70P, from the company Filtrona Porus Technologies. This is an MDI-based hydrophilic PUR foam (MDI being a type of prepolymer).

[0171] The described combination permits an optimal straightening effect of the tube lumen and optimal protection of the adjacent body tissues.

[0172] Alternatively, it is possible to use softer foam sheaths whose elastic properties correspond, for example, to those of the material MS SuperSoft 60P.

[0173] Hard, less deformable foam sheaths can be produced, for example, from fiber-reinforced foams, such as, for example, MS 70P grade composite foam.

[0174] FIG. 11 describes a further option for the atraumatic securing of the distal end of the catheter shaft in drains having waisted balloon components according to the invention, in which the fixation lines V and H are offset toward each other in such a way that a pronounced counter-rolling movement of the terminal balloon segments occurs. The amount of the offset D of the fixation lines V and H on both sides should be, in total, smaller than/equal to the distance E between the inflection points WD of the shoulder radii of the distal balloon enlargement and WP of the proximal enlargement. The offset D is referred to the apices Z of the front and rear balloon radii, in similar fashion to its determination in the preceding figures.

[0175] The thus-enabled axial counter-rolling of the balloon enlargements 4 and 5 toward the external and internal anus are intended to permit dislocation-stable and well-sealing placement of the drain in the anus even in the presence of a shortened anal canal deviating from the norm. Here again, the free distal end 7 of the shaft tube is preferably connected congruently with the forward fixation line V of the distal balloon shaft end 9.

[0176] In the presence of a force acting axially on the shaft from a proximal direction, analogously to the embodiment of FIG. 3, given the inventive implementation of the balloon envelope and the shaft tube, the shaft tube end 7 remains limited in its maximal deflection inside the transanally placed balloon, such that a defined apex S is not surpassed by the free end of the shaft tube.

[0177] FIG. 12 describes an alternative embodiment of the components of the shaft body (shaft tube and sheath) according to the invention, in which the design principle of axial buckling and radial folding of the shaft tube 6 can be realized from diverse elements by segmenting the shaft into sections of materials having different hardnesses, wall thicknesses and deformation properties.

[0178] For example, the transanal segment of the shaft, or also the preanal or next proximally adjacent segment of the shaft, can, like the intrarectal segment of the shaft, be made of relatively hard, low-deformability material. The described buckling and folding effect can thus be limited to individual segments, while other segments are largely lumen-stable and counteract the reversible elastic deformation of the shaft.

[0179] In addition to the use of elastically deformable materials, it is also possible to contemplate the use of non-elastically, plastically acting shaft segments, made, for example, from PVC or PUR/PVC blends.

[0180] The filling of the proposed balloon elements preferably takes place through a filling conduit integrated into the wall of the shaft tube. A compressible, gaseous medium, such as air, is preferably used.

[0181] For volume-controlled filling, an injection element is preferably included with the device and specifies the particular filling volume by means of a suitable marking on the syringe body.

[0182] The filling of the balloon is preferably effected incompletely, with a filling volume corresponding to the volume accepted by the freely unfolded, unpressurized balloon mounted on the shaft, minus the corresponding volume accepted by the transanal balloon segment. The transanal balloon segment is defined in this context as the portion of the balloon between the inflection points WD and WP (see FIG. 11).

[0183] Particularly advantageous for attaining an optimally low filling pressure in conjunction with sufficient anchoring and sealing by the balloon is filling with a filling volume that corresponds to the previously determined filling volume, but increased by approximately 10 to 30 percent of the volume accepted by the transanal balloon segment.

[0184] The elastic folding and straightening behavior of a foam-sheathed shaft tube under axially and radially imposed force will be described further with reference to a specific exemplary embodiment.

[0185] Preferably, the shaft tube 6 is implemented as follows: [0186] Elastollan 1180A (from the company BASF) [0187] Internal diameter 15 mm [0188] Wall thickness 0.3 mm

[0189] The shaft tube is connected to a dumbbell-shaped balloon 2, the latter being charged with variable filling pressures via a filling conduit. The foam sheath 16 is disposed continuously on the outer surface of the shaft tube inside the balloon and has a wall thickness of 2 mm. The foam material corresponds to the specification of type MS SuperSoft 70P, from the company Filtrona Porus Technologies.

[0190] The following table shows the maximum narrowing of the lumen of the shaft tube (the drainage lumen) that occurs in each case with a specific filling pressure imposed on all sides of the shaft body inside the balloon.

[0191] The respective smallest transverse distance between the mutually approaching inner walls of the tube is taken as the drainage lumen dimension DM (especially its diameter) in the balloon-supporting section of the shaft.

TABLE-US-00001 TABLE Relationship between filling pressure and drainage lumen in a specific exemplary implementation of a foam-sheathed shaft tube Balloon filling Drainage lumen pressure (mbar) dimension DM (mm) 0 14 5 12-14 10  9-11 15 6-9 20 5-8 25 4-6 30 3-5 35 1-3 40 0-2 45  0

[0192] The axial kinking of the shaft tube in response to a force F.sub.kink acting on the shaft somewhere along the shaft longitudinal axis occurs in this specific implementation of the device in response to a weight force of approximately 300 to 350 grams imposed in the region of the rear fixation line H.

[0193] The invention also proposes simple embodiments of the drainage device not provided with a sheath and having only a shaft tube as the balloon-supporting body. The following table gives the deformation behavior of a shaft tube of equivalent design without a sheath.

TABLE-US-00002 TABLE Relationship between filling pressure and drainage lumen with specific exemplary embodiments of a non-sheathed shaft tube Balloon filling Drainage lumen pressure (mbar) dimension DM (mm) 0 14 5  8-12 10 5-8 15 2-4 20 1-2 25  0

[0194] The axial kinking of the shaft tube in response to a force F.sub.kink acting on the shaft somewhere along the shaft longitudinal axis occurs in this specific implementation of the device in response to a weight force of approximately 200 to 250 grams imposed in the region of the rear fixation line H.

[0195] In addition to the transanal use of the device, intestinal tubes fashioned according to the invention can also be inserted and placed for perforation-safe placement in transabdominal, surgically created stomata/openings to the bowel or other natural body openings.

[0196] The described device can also be used, in the implementations proposed here, as a transanal inflow catheter or in the context of postoperative transanal tamponade following anal or rectal surgery. Particularly advantageous here have been found to be the transanal sealing function brought about by the middle, waisted balloon segment and the atraumatic positioning of the shaft tip even in the event of accidental, forced axial [word missing] of the shaft into the intestinal lumen, and the use of additional abutment bodies or foam bodies in the intrarectal and/or preanal enlargement of the balloon component.