Trans-anal inflow catheter and method for intermittently triggering a reflex-coordinated defecation

Abstract

A device for transanally introducing an infusion into the rectum of a patient, the device comprising an inflatable balloon having a waisted shape, two terminal sections of larger radius and, a middle section of a reduced radius, and is placed transanally, the distally adjoining radially enlarged balloon section being placed intrarectally and the proximally adjoining radially enlarged balloon section extracorporeally, wherein both balloon ends taper to the dimension of a shaft supporting the balloon and are fixed on the surface of the shaft such that as the balloon is filled, the two enlarged balloon sections move toward each other in opposite axial directions, and wherein the two radially enlarged balloon sections are enlarged relative to the middle balloon section, such that when the balloon is placed transanally, during the filling process the two radially enlarged balloon sections draw down over the middle, balloon section and contact each other, and to a method for filling the catheter balloon.

1 . A device for transanally introducing an infusion into the rectum or colon of a patient, said device comprising an inflatable balloon having a waisted shape, comprising two terminal balloon sections of larger radius and generally spherical or discoid shape, and, disposed between them, a middle, tapered balloon section having a reduced radius, the device being adapted to be placed transanally, such that the distally adjoining radially enlarged balloon section is placed intrarectally and the proximally adjoining radially enlarged balloon section extracorporeally, wherein both balloon ends taper a shaft dimension of a catheter shaft supporting the balloon and, beginning at an inflection point of their longitudinal section, are inwardly invaginated, or inverted, and in the inverted or invaginated state are fixed on the outer jacket surface of the catheter shaft such that as the balloon is filled, the two radially enlarged balloon sections move toward each other in opposite axial directions, and wherein the two radially enlarged balloon sections are enlarged relative to the tapered, middle balloon section, such that when the balloon is placed transanally, during the filling process the two radially enlarged balloon sections draw down over the middle tapered balloon section and come into direct contact with each other, thereby limiting their relative movements, as a result of which the distal tip of the catheter shaft, in its non-deflected, resting state, retracts into a protected, injury-preventing position inside the intrarectal balloon section and in so doing comes to lie entirely proximally of a distal apex of a circle about a center point which is located on an axis of symmetry and whose tangent in an inflection point corresponds to a tangent to the non-invaginated longitudinal section of the balloon. 
     
     
         2 . The device according to  claim 1 , wherein a distal tip of the catheter shaft in its non-deflected, resting state comes to lie entirely proximally of a plane which is intersected perpendicularly by the axis of symmetry and which is fully tangent distally to the intrarectal balloon section. 
     
     
         3 . The device according to  claim 1 , wherein the middle, tapered balloon section is separated from each of the generally spherical or discoid balloon sections by a respective inflection point of the cross-sectional radius, and in the non-expanded filled state exhibits an axial length larger than a minimum diameter thereof. 
     
     
         4 . The device according to  claim 1 , wherein the non-expanded filled state, the invaginated or inverted balloon ends each have an axial extent (B 1 , B 2 ) greater than a minimum diameter thereof. 
     
     
         5 . The device according to  claim 1  wherein in the non-expanded filled state, the sum of axial extents (B 1 , B 2 ) of the inversions of the two balloon ends is at least equal to the length of the middle, tapered balloon section (A):
     B   1   +B   2   ≧A.    
 
     
     
         6 . The device according to  claim 2 , wherein the catheter distal tip projects by a dimension (C) beyond a forward fixation line of the forward balloon end on the catheter shaft, and the inversion depth (B) is greater than, or equal to, half of balloon section length (A) plus the length (C) of a projecting tip piece ( 18 ):
     B   1   =B   2   ≧A/ 2+ C,      or alternatively:
     B   1   =B   2   ≧A/ 2+ C/ 2. 
   
     
     
         7 . The device as according to  claim 1 , wherein upon axial deflection of the catheter shaft toward the bowel in response to forces that occur during use, a catheter tip does not move more than a distance (W) beyond the distal apex of the forward balloon radius, and the distance (W) is obtained from the distance between the distal apex and an apex comprising a forward intersection point of the axis of symmetry with a circle of diameter around a center point on the axis of symmetry at the level of the attachment of the intrarectal balloon section to the catheter shaft. 
     
     
         8 . The device according to  claim 1 , wherein the envelope of the evacuated, ready-to-use catheter balloon is placed on the shaft, or clings closely thereto, in such fashion that the intrarectal and the transanal balloon sections lie in a shaft region between the fixations of the upper and lower balloon ends, and a preanal balloon portion extends in the proximal direction in a pocket-like manner over gripping depressions. 
     
     
         9 . The device according to  claim 8 , wherein the gripping depressions are disposed on the shaft in direct proximal adjacency to a rear balloon fixation line. 
     
     
         10 . The device according to  claim 1 , wherein the catheter shaft is provided with a waist portion in the region of the transanal placement inside the anal canal. 
     
     
         11 . The device according to  claim 1 , wherein inserted in a duct of the catheter shaft is a non-return element adapted to prevent retrograde backflow of fluid directed away from the patient through the catheter. 
     
     
         12 . The device according to  claim 11  wherein the non-return element in the duct comprises a thin-walled tube element having a wall thickness of 5 to 15 micrometers, and having a diameter of the duct, such that the distal end of the tube lies freely in the duct over a length of approximately 5 to 10 mm, and the tube proximal end is sealingly connected to an inner wall of the duct, thereby ensuring that the tube element opens in the presence of a flow of medium through the duct toward a tip thereof, and the tube element closes by collapsing in the presence of flow in an opposite direction. 
     
     
         13 . The device according to  claim 1 , wherein the catheter is connected by a fixed tube connection to a bag-like container for irrigation fluid, as a ready-to-use, disposal product. 
     
     
         14 . The device according to  claim 13 , wherein the fixed tube connection is provided with a breakable seal and/or with a non-return valve. 
     
     
         15 . The device according to  claim 1  wherein the catheter comprises a disposable catheter, connectable via a filling conduit to a reusable filling device, the filling device being implemented as a manually operable pump balloon with a manometer indicating balloon filling pressure. 
     
     
         16 . The device according to  claim 15 , and comprising a manometer indicating the balloon filling pressure, wherein the manometer comprises a scale on which the filling pressure ranges required for use of the catheter are specified by markings. 
     
     
         17 . The device according to  claim 1 , wherein a valve element limits the balloon pressure, and is disposed in or on a reusable filling device or is integrated into a selected one of the balloon filling conduit of the single-use catheter and the catheter-bag unit. 
     
     
         18 . A method for filling the catheter balloon of a device for transanally introducing an infusion into the rectum or colon of a patient by means of a filling device, wherein a fill volume or the filling pressure prevailing in the balloon is increased in a plurality of steps until there occurs a gradual, user-controllable, pneumatically initiated expansion of portions of the bowel wall, thereby triggering a coordinated defecation reflex, wherein the timing and intensity of the triggering can be determined by the user. 
     
     
         19 . The method according to  claim 18 , wherein:
 a) the pressure in the transanally placed catheter balloon is initially set to a first, low pressure range of approximately 10 to 25 mbar, which anchors and seals the catheter in the anus;   b) the inflow fluid is introduced into the rectum by squeezing it out of the container;   c) after a suitable retention time, the filling pressure in the catheter balloon is raised to approximately 30 to 60 mbar, causing only the rectal bowel wall to be initially included in the expansion, and at which the defecation reflex is triggered in most users;   d) upon a further increase in the filling pressure in the catheter balloon, to approximately 60 to 120 mbar, the anal canal is also caused to expand, to increase intensity of the stimulus triggering the defecation reflex.   
     
     
         20 . The method according to  claim 19 , wherein by the sequential pneumatic triggering of a defecation reflex, a volume of the irrigation fluid is reduced to a value of about 80 to 120 ml per administration, the fluid being delivered as ready-to-use solution through a fixed feed conduit to the catheter, and the balloon is disposable.