TRANS-ANAL INFLOW CATHETER FOR INTERMITTENTLY TRIGGERING A REFLEX-COORDINATED DEFECATION

Abstract

A device for intermittently triggering a coordinated defecation reflex in the rectum or colon of a patient, said device comprising a catheter with an inflexible catheter shaft and a preformed inflatable balloon, the inflatable balloon comprising at least an intrarectal balloon segment having, in an inflated, but unpressurized state of the balloon, a generally spherical or discoid shape and a maximal first radius, and being adapted to be placed intrarectally; wherein the inflatable balloon is fixed onto the catheter shaft only at fixation points located at the ends of the inflatable balloon, wherein both ends of the inflatable balloon taper to a shaft dimension of the catheter shaft supporting the inflatable balloon, with the distal end of the balloon having a tapered second radius; wherein, in an inflated, but unpressurized state of the balloon, the difference between the first radius of the intrarectal balloon segment and the second radius of the distal tapered balloon end is equal to a first difference, and further wherein the first difference is greater than a distance between a distal front side of the catheter and a distal fixation point, where the tapered distal end of the balloon is in contact with the catheter shaft and is fixed thereto; wherein the distal front side of the catheter is at a distalmost extension of the catheter shaft or of a distal tip piece of the catheter shaft; and wherein the inflatable balloon is configured such that when the inflatable balloon is in a pressurized state exceeding 30 mbar, at least a portion of the distal intrarectal balloon segment engages and expands a side wall of the rectum or colon of the patient, whereby to trigger a coordinated defecation reflex in the rectum or colon of the patient.

Claims

1.-96. (canceled)

97. A device for intermittently triggering a coordinated defecation reflex in the rectum or colon of a patient, said device comprising a catheter with an inflexible catheter shaft and a preformed inflatable balloon, the inflatable balloon comprising at least an intrarectal balloon segment having, in an inflated, but unpressurized state of the balloon, a generally spherical or discoid shape and a maximal first radius, and being adapted to be placed intrarectally; wherein the inflatable balloon is fixed onto the catheter shaft only at fixation points located at the ends of the inflatable balloon, wherein both ends of the inflatable balloon taper to a shaft dimension of the catheter shaft supporting the inflatable balloon, with the distal end of the balloon having a tapered second radius; wherein, in an inflated, but unpressurized state of the balloon, the difference between the first radius of the intrarectal balloon segment and the second radius of the distal tapered balloon end is equal to a first difference, and further wherein the first difference is greater than a distance between a distal front side of the catheter and a distal fixation point, where the tapered distal end of the balloon is in contact with the catheter shaft and is fixed thereto; wherein the distal front side of the catheter is at a distalmost extension of the catheter shaft or of a distal tip piece of the catheter shaft; and wherein the inflatable balloon is configured such that when the inflatable balloon is in a pressurized state exceeding 30 mbar, at least a portion of the distal intrarectal balloon segment engages and expands a side wall of the rectum or colon of the patient, whereby to trigger a coordinated defecation reflex in the rectum or colon of the patient.

98. The device according to claim 97, wherein, the catheter balloon comprises, additionally to the intrarectal balloon segment, a tapered transanal balloon section disposed proximally adjacent to the intrarectal balloon segment, the tapered transanal balloon section having a third radius, and wherein the first radius is larger than the third radius.

99. The device according to claim 98, wherein (i) in the pressurized state of the inflatable balloon at 30 mbar, the difference between the first radius of the intrarectal balloon segment and a third radius of the transanal balloon section is equal to a second difference, and (ii) in the pressurized state of the inflatable balloon at 100 mbar, the difference between the first radius of the intrarectal balloon segment and the third radius of the transanal balloon section is equal to a third difference, and further wherein the second difference is less than the third difference.

100. The device according to claim 98, wherein, in case of an increased pressure in the balloon beyond 100 mbar, the difference between the larger radius of the distal terminal balloon section and the reduced radius of the proximally adjacent, tapered balloon section will approximate a constant value.

101. The device according to claim 98, wherein the tapered transanal balloon section being adapted to be placed transanally expands by less than 20%, or by less than 15%, at a pressure increase from 30 to 100 mbar.

102. The device according to claim 97, wherein the intrarectal balloon segment being adapted to be placed intrarectally expands by more than 15%, or by more than 20%, at a pressure increase from 30 to 100 mbar.

103. The device according to claim 97, wherein the balloon is made from polyurethane material, or from a material with the same compliance and elasticity characteristics as polyurethane.

104. The device according to claim 98, wherein the tapered transanal balloon section is configured to terminate flush with the anus.

105. The device according to claim 98, wherein the length of the tapered transanal balloon section is designed such that in case of a placement of the device in a patient, the tapered transanal balloon section shall project over the anus to form a pre-anal segment, wherein the pre-anal segment of the balloon is pre-formed into a conical balloon section having a conical shape with a distal end and a proximal end, wherein a pre-formed diameter at the proximal end of the conical balloon section is 30 to 70% larger, or 40 to 60% larger, than a pre-formed diameter at the distal end of the conical balloon section.

106. The device according to claim 98, wherein the intrarectal balloon segment adapted to be placed intrarectally and the tapered transanal balloon section adapted to be placed transanally are manufactured separately, or are manufactured from different materials and/or with different characteristics, or are manufactured from materials with different material characteristics like different durometers.

107. The device according to claim 98, wherein the inflatable balloon has a waisted shape, comprising the intrarectal balloon segment of the first radius and of generally spherical or discoid shape, a proximal terminal balloon section of a fourth radius and of generally spherical or discoid shape, and, disposed between them, the tapered transanal balloon section having a third radius, with the tapered balloon section of the device being adapted to be placed transanally, and the intrarectal balloon segment being adapted to be placed intrarectally, and the proximal terminal balloon section being adapted to be placed extracorporeally, and wherein the fourth radius is larger than the third radius.

108. The device according to claim 97, wherein the ends of the inflatable balloon, beginning at an inflection point of their longitudinal section, are inwardly invaginated, or inverted, and in the inverted or invaginated state are fixed on an outer jacket surface of the catheter shaft.

109. The device as in claim 98, characterized in that an 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 respective fixations of the upper and lower balloon ends (6, 7), and a preanal balloon portion extends in the proximal direction in a pocket-like manner over gripping depressions (12).

110. The device as in claim 97, characterized in that gripping depressions (12) are disposed on the shaft in direct proximal adjacency to a rear balloon fixation line (14).

111. The device as in claim 97, characterized in that the catheter shaft has a waist (23) in a region of its transanal placement inside the anal canal.

112. The device as in claim 97, characterized in that inserted in a duct (25) of the catheter shaft, or integrated into a tubing line, which connects the catheter shaft with a fluid containing containment, is a non-return element that prevents any retrograde backflow of fluid directed away from the patient through the catheter.

113. The device as in claim 112, characterized in that the non-return element in the duct (25) is a thin-walled tube element having a wall thickness of 5 to 15 micrometers, and having the diameter of the duct (25), wherein the distal end of the tube lies freely in the duct (25) over a length of approximately 5 to 10 mm and its proximal end is sealingly connected to the inner wall of the duct (25), thereby ensuring that the tube element opens in the presence of a flow of medium through the duct toward the tip and the tube element closes by collapsing in the presence of flow in the opposite direction.

114. The device as in claim 97, characterized in that the catheter is an inflow catheter and is connected by a fixed tube connection (32) to a container (33) for the irrigation fluid as a ready-to-use, disposal product.

115. The device as in claim 114, whereby small volumes of fluid as e.g. 5 to 15 ml can be squeezed out from the container (33) into the rectum of a patient, as a micro-enema.

116. The device as in claim 114, whereby a diameter of an irrigation canal of the device is reduced in its dimension to a volume of equal or less than 1 ml, or to a volume of less than 0.5 ml, so as to minimize the volume loss inside this volume.

117. The device as in claim 97, comprising a disposable catheter, characterized in that the disposable catheter is connectable via a filling conduit (34) to a filling device (27), or to a filling device (27) which is implemented as a manually operable pump balloon with a manometer indicating a balloon filling pressure.

118. The device as in claim 97, comprising a manometer indicating a balloon filling pressure, characterized in that the manometer comprises a scale on which filling pressure ranges required for the use of the catheter are specified by suitable markings.

119. The device as in claim 97, characterized by a valve element that limits a balloon pressure and is disposed in or on a reusable filling device (27) or is integrated into a balloon filling conduit (34) of the catheter or into a catheter-bag unit.

120. The device as in claim 97, further comprising a user-adjustable decompression mechanism (37), that when being released, opens the balloon in a pressurized state permanently to an ambient surrounding, once a certain pressure inside the balloon has been reached or exceeded, whereby a pressure increase inside the balloon is configured to be caused by a peristaltic contraction of the colo-rectal bowel segment, due to the released coordinated defecation reflex.

121. The device according to claim 98, wherein, in an inflated, but unpressurized state of the balloon, the difference between the first radius of the intrarectal balloon segment and the third radius of the tapered transanal balloon section is equal to a second difference, and further wherein the second difference is greater than the distance between the distal front side of the catheter and the distal fixation point of the balloon to the catheter shaft; wherein the catheter balloon or at least the intrarectal balloon segment is pre-formed into a working dimension associated with a filling state characterized by an initial fill volume or an initial filling pressure, in which the filling pressure required for anchoring the catheter within the rectum or colon of the patient is approximately the same as the pressure prevailing in the rectum or abdomen; wherein the catheter balloon is configured such that an increase above the initial fill volume or filling pressure causes a gradual, user-controllable expansion of the catheter balloon such that at least a portion of the catheter balloon engages and expands a side wall of the rectum or colon of the patient, whereby to trigger a coordinated defecation reflex by generating a reflex-triggering stimulus of an intensity which can, determined by the user, substantially exceed the intensity achievable by an irrigation with fluid media; wherein the catheter balloon or the intrarectal balloon segment has a compliance reserve; wherein the catheter balloon or the intrarectal balloon segment of the catheter balloon distends elastically from the pre-formed working dimension up to a final dimension; and wherein further distention of the catheter balloon or the intrarectal balloon segment of the catheter balloon is not possible once the catheter balloon or intrarectal balloon segment has distended to its final dimension, and no further dimensional expansion is allowed, in order to avoid uncontrolled dilation and trauma.

122. The device according to claim 97, wherein the catheter balloon or at least the intrarectal balloon segment is pre-formed beyond a working dimension associated with a filling state characterized by an initial fill volume or an initial filling pressure, in which the filling pressure in the catheter balloon required for anchoring the catheter within the rectum or colon of the patient is approximately the same as the pressure prevailing in the rectum or abdomen; wherein the catheter balloon is configured such that an increase above the initial fill volume or filling pressure causes a gradual, user-controllable expansion of the catheter balloon such that at least a portion of the catheter balloon engages and expands a side wall of the rectum or colon of the patient, whereby to trigger a coordinated defecation reflex by generating a reflex-triggering stimulus of an intensity which can, determined by the user, substantially exceed the intensity achievable by an irrigation with fluid media; and wherein the catheter balloon or the intrarectal balloon segment is made of a non-volume-expandable, non-elastic material, such that no further dimensional expansion is allowed beyond a final dimension to which the catheter balloon or the intrarectal balloon segment is pre-formed, in order to avoid uncontrolled dilation and trauma.

123. The device according to claim 98, wherein the catheter balloon or at least the intrarectal balloon segment is pre-formed into a working dimension associated with a filling state characterized by an initial fill volume or an initial filling pressure, in which the filling pressure required for anchoring the catheter within the rectum or colon of the patient is approximately the same as the pressure prevailing in the rectum or abdomen; wherein the catheter balloon is configured such that an increase above the initial fill volume or filling pressure causes a gradual, user-controllable expansion of the catheter balloon such that at least a portion of the catheter balloon engages and expands a side wall of the rectum or colon of the patient, whereby to trigger a coordinated defecation reflex; wherein the catheter balloon or the intrarectal balloon segment has a compliance reserve; wherein the catheter balloon or the intrarectal balloon segment of the catheter balloon distends elastically; wherein the transanal balloon segment expands by less than 20% at a pressure increase from 30 to 100 mbar, and wherein gripping depressions (12) are disposed on the catheter shaft in direct proximal adjacency to a rear balloon fixation line (14).

124. The device according to claim 97, wherein the catheter balloon or at least the intrarectal balloon segment is pre-formed into a working dimension associated to with filling state characterized by an initial fill volume or an initial filling pressure, in which the filling pressure required for anchoring the catheter within the rectum or colon of the patient is approximately the same as the pressure prevailing in the rectum or abdomen; wherein the catheter balloon is configured such that an increase above the initial fill volume or filling pressure causes a gradual, user-controllable expansion of the catheter balloon such that at least a portion of the catheter balloon engages and expands a side wall of the rectum or colon of the patient, whereby to trigger a coordinated defecation reflex; wherein the catheter balloon or the intrarectal balloon segment has a compliance reserve; wherein the catheter balloon or the intrarectal balloon segment of the catheter balloon distends elastically from the pre-formed working dimension up to a final dimension and is designed to expand by more than 15%, at a pressure increase from 30 to 100 mbar up to a final dimension, where distention comes to a rest and no further dimensional expansion is allowed, in order to avoid uncontrolled dilation and trauma;

125. A method for intermittently triggering a coordinated defecation reflex in the rectum or colon of a patient, said method comprising: providing a catheter comprising an inflexible catheter shaft and a preformed inflatable balloon, the inflatable balloon comprising at least an intrarectal balloon segment having, in an inflated, but unpressurized state of the balloon, a generally spherical or discoid shape and a maximal first radius, and which is adapted to be placed intrarectally; wherein the inflatable balloon is fixed onto the catheter shaft only at fixation points located at the ends of the inflatable balloon, wherein both ends of the inflatable balloon taper to a shaft dimension of the catheter shaft supporting the inflatable balloon, with the distal end of the balloon having a tapered second radius; and wherein, in an inflated, but unpressurized state of the balloon, the difference between the first radius of the intrarectal balloon segment and the second radius of the distal tapered balloon end is equal to a first difference, and further wherein the first difference is greater than a distance between a distal front side of the catheter and a distal fixation point, where the tapered distal end of the balloon is in contact with to the catheter shaft and is fixed thereto, wherein the distal front side of the catheter is at a distalmost extension of the catheter shaft or of a distal tip piece of the catheter shaft; inserting the catheter in the rectum or colon of a patient; pressurizing the balloon to a pressure exceeding 30 mbar, whereby at least a portion of the distal intrarectal balloon segment engages and expands a side wall of the rectum or colon of the patient, whereby to trigger a coordinated defecation reflex in the rectum or colon of the patient.

126. The method according to claim 125, wherein the catheter balloon comprises, additionally to the intrarectal balloon segment, a tapered transanal balloon section disposed proximally adjacent to the intrarectal balloon segment, the tapered transanal balloon section having a second radius, and wherein the first radius is larger than the second radius.

127. The method according to claim 126, wherein (i) in the pressurized state of the inflatable balloon at 30 mbar, the difference between the first radius of the intrarectal balloon segment and a third radius of the transanal balloon section is equal to a second difference, and (ii) in the pressurized state of the inflatable balloon at 100 mbar, the difference between the first radius of the intrarectal balloon segment and the third radius of the transanal balloon section is equal to a third difference, and further wherein the second difference is less than the third difference.

128. The method according to claim 126, wherein, in case of an increased pressure in the balloon beyond 100 mbar, the difference between the larger radius of the distal terminal balloon section and the reduced radius of the proximally adjacent, tapered balloon section will approximate a constant value.

129. The device according to claim 126, wherein the tapered transanal balloon section being adapted to be placed transanally expands by less than 20%, or by less than 15%, at a pressure increase from 30 to 100 mbar.

130. The method according to claim 125, wherein the intrarectal balloon segment being adapted to be placed intrarectally expands by more than 15%, or by more than 20%, at a pressure increase from 30 to 100 mbar.

131. The method according to claim 125, wherein the balloon is made from polyurethane material, or from a material with the same compliance and elasticity characteristics as polyurethane.

132. The method according to claim 126, wherein the tapered transanal balloon section is configured to terminate flush with the anus.

133. The method according to claim 126, wherein the length of the tapered transanal balloon section is designed such that in case of a placement of the device in a patient, the tapered transanal balloon section shall project over the anus to form a pre-anal segment, wherein the pre-anal segment of the balloon is pre-formed into a conical balloon section having a conical shape with a distal end and a proximal end, wherein a pre-formed diameter at the proximal end of the conical balloon section is 30 to 70% larger, or 40 to 60% larger, than a pre-formed diameter at the distal end of the conical balloon section.

134. The method according to claim 126, wherein the intrarectal balloon segment adapted to be placed intrarectally and the tapered transanal balloon section adapted to be placed transanally are manufactured separately, or are manufactured from different materials and/or with different characteristics, or are manufactured from materials with different material characteristics like different durometers.

135. The method according to claim 126, wherein the inflatable balloon has a waisted shape, comprising the intrarectal balloon segment of the first radius and of generally spherical or discoid shape, a proximal terminal balloon section of a fourth radius and of generally spherical or discoid shape, and, disposed between them, the tapered transanal balloon section having a third radius, with the tapered balloon section of the device being adapted to be placed transanally, and the intrarectal balloon segment being adapted to be placed intrarectally, and the proximal terminal balloon section being adapted to be placed extracorporeally, and wherein the fourth radius is larger than the third radius.

136. The method according to claim 125, wherein the ends of the inflatable balloon, beginning at an inflection point of their longitudinal section, are inwardly invaginated, or inverted, and in the inverted or invaginated state are fixed on an outer jacket surface of the catheter shaft.

137. The method as in claim 126, characterized in that an 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 respective fixations of the upper and lower balloon ends (6, 7), and a preanal balloon portion extends in the proximal direction in a pocket-like manner over gripping depressions (12).

138. The method as in claim 125, characterized in that gripping depressions (12) are disposed on the shaft in direct proximal adjacency to a rear balloon fixation line (14).

139. The method as in claim 125, characterized in that the catheter shaft has a waist (23) in a region of its transanal placement inside the anal canal.

140. The method as in claim 125, characterized in that inserted in a duct (25) of the catheter shaft, or integrated into a tubing line, which connects the catheter shaft with a fluid containing containment, is a non-return element that prevents any retrograde backflow of fluid directed away from the patient through the catheter.

141. The method as in claim 140, characterized in that the non-return element in the duct (25) is a thin-walled tube element having a wall thickness of 5 to 15 micrometers, and having the diameter of the duct (25), wherein the distal end of the tube lies freely in the duct (25) over a length of approximately 5 to 10 mm and its proximal end is sealingly connected to the inner wall of the duct (25), thereby ensuring that the tube element opens in the presence of a flow of medium through the duct toward the tip and the tube element closes by collapsing in the presence of flow in the opposite direction.

142. The method as in claim 125, characterized in that the catheter is an inflow catheter and is connected by a fixed tube connection (32) to a container (33) for the irrigation fluid as a ready-to-use, disposal product.

143. The method as in claim 142, whereby small volumes of fluid as e.g. 5 to 15 ml can be squeezed out from the container (33) into the rectum of a patient, as a micro-enema.

144. The method as in claim 142, whereby a diameter of an irrigation canal of the device is reduced in its dimension to a volume of equal or less than 1 ml, or to a volume of less than 0.5 ml, so as to minimize the volume loss inside this volume.

145. The method as in claim 125, comprising a disposable catheter, characterized in that the disposable catheter is connectable via a filling conduit (34) to a filling device (27), or to a filling device (27) which is implemented as a manually operable pump balloon with a manometer indicating a balloon filling pressure.

146. The method as in claim 125, comprising a manometer indicating a balloon filling pressure, characterized in that the manometer comprises a scale on which filling pressure ranges required for the use of the catheter are specified by suitable markings.

147. The method as in claim 125, characterized by a valve element that limits a balloon pressure and is disposed in or on a reusable filling device (27) or is integrated into a balloon filling conduit (34) of the catheter or into a catheter-bag unit.

148. The method as in claim 125, further comprising a user-adjustable decompression mechanism (37), that when being released, opens the balloon in a pressurized state permanently to an ambient surrounding, once a certain pressure inside the balloon has been reached or exceeded, whereby a pressure increase inside the balloon is configured to be caused by a peristaltic contraction of the colo-rectal bowel segment, due to the released coordinated defecation reflex.

149. The method according to claim 126, wherein, in an inflated, but unpressurized state of the balloon, the difference between the first radius of the intrarectal balloon segment and the third radius of the tapered transanal balloon section is equal to a second difference, and further wherein the second difference is greater than a the distance between a the distal front side of the catheter and a the distal fixation point of the balloon to the catheter shaft; wherein the catheter balloon or at least the intrarectal balloon segment is pre-formed into a working dimension associated with a filling state, characterized by an initial fill volume or an initial filling pressure, in which the filling pressure required for anchoring the catheter within the rectum or colon of the patient is approximately the same as the pressure prevailing in the rectum or abdomen; wherein the catheter balloon is configured such that an increase above the initial fill volume or filling pressure causes a gradual, user-controllable expansion of the catheter balloon such that at least a portion of the catheter balloon engages and expands a side wall of the rectum or colon of the patient, whereby to trigger a coordinated defecation reflex by generating a reflex-triggering stimulus of an intensity which can, determined by the user, substantially exceed the intensity achievable by an irrigation with fluid media; wherein the catheter balloon or the intrarectal balloon segment has a compliance reserve; wherein the catheter balloon or the intrarectal balloon segment of the catheter balloon distends elastically from the pre-formed working dimension up to a final dimension; and wherein further distention of the catheter balloon or the intrarectal balloon segment of the catheter balloon is not possible once the catheter balloon or intrarectal balloon segment has distended to its final dimension, and no further dimensional expansion is allowed, in order to avoid uncontrolled dilation and trauma.

150. The method according to claim 125, wherein the catheter balloon or at least the intrarectal balloon segment is pre-formed beyond a working dimension associated with a filling state characterized by an initial fill volume or an initial filling pressure, in which the filling pressure in the catheter balloon required for anchoring the catheter within the rectum or colon of the patient is approximately the same as the pressure prevailing in the rectum or abdomen; wherein the catheter balloon is configured such that an increase above the initial fill volume or filling pressure causes a gradual, user-controllable expansion of the catheter balloon such that at least a portion of the catheter balloon engages and expands a side wall of the rectum or colon of the patient, whereby to trigger a coordinated defecation reflex by generating a reflex-triggering stimulus of an intensity which can, determined by the user, substantially exceed the intensity achievable by an irrigation with fluid media; and wherein the catheter balloon or the intrarectal balloon segment is made of a non-volume-expandable, non-elastic material, such that no further dimensional expansion is allowed beyond a final dimension to which the catheter balloon or the intrarectal balloon segment is pre-formed, in order to avoid uncontrolled dilation and trauma.

151. The method according to claim 126, wherein the catheter balloon or at least the intrarectal balloon segment is pre-formed into a working dimension associated with a filling state, characterized by an initial fill volume or an initial filling pressure, in which the filling pressure required for anchoring the catheter within the rectum or colon of the patient is approximately the same as the pressure prevailing in the rectum or abdomen; wherein the catheter balloon is configured such that an increase above the initial fill volume or filling pressure causes a gradual, user-controllable expansion of the catheter balloon such that at least a portion of the catheter balloon engages and expands a side wall of the rectum or colon of the patient, whereby to trigger a coordinated defecation reflex; wherein the catheter balloon or the intrarectal balloon segment has a compliance reserve; wherein the catheter balloon or the intrarectal balloon segment of the catheter balloon distends elastically; wherein the transanal balloon segment expands by less than 20%, at a pressure increase from 30 to 100 mbar, and wherein gripping depressions (12) are disposed on the catheter shaft in direct proximal adjacency to a rear balloon fixation line (14).

152. The method according to claim 125, wherein the catheter balloon or at least the intrarectal balloon segment is pre-formed into a working dimension associated with a filling state, characterized by an initial fill volume or an initial filling pressure, in which the filling pressure required for anchoring the catheter within the rectum or colon of the patient is approximately the same as the pressure prevailing in the rectum or abdomen; wherein the catheter balloon is configured such that an increase above the initial fill volume or filling pressure causes a gradual, user-controllable expansion of the catheter balloon such that at least a portion of the catheter balloon engages and expands a side wall of the rectum or colon of the patient, whereby to trigger a coordinated defecation reflex; wherein the catheter balloon or the intrarectal balloon segment has a compliance reserve; wherein the catheter balloon or the intrarectal balloon segment of the catheter balloon distends elastically from the pre-formed working dimension up to a final dimension and is designed to expand by more than 15%, at a pressure increase from 30 to 100 mbar up to a final dimension, where distention comes to a rest and no further dimensional expansion is allowed, in order to avoid uncontrolled dilation and trauma,

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0159] Further features, characteristics, advantages and effects of the invention will become apparent from the following description of preferred embodiments of the invention and by reference to the drawing. Therein:

[0160] FIG. 1a shows an embodiment of a catheter according to the invention in a schematic longitudinal section, the balloon ends being mounted on the catheter shaft in an inverted manner according to the invention;

[0161] FIG. 1b shows the geometric structure of the apex of the distal balloon radius;

[0162] FIG. 1c shows the geometric structure of the distal plane tangent to the intrarectal balloon section;

[0163] FIG. 2 is a representation similar to FIG. 1a of another embodiment of the invention, in which a catheter tip extends beyond the forward fixation line of the end of the balloon shaft;

[0164] FIG. 3 is a representation similar to FIG. 2 showing additional auxiliary lines, such that the reference point for determining the inversion depth B is not the forward balloon radius, but rather the largest diameter D of the intrarectal balloon segment;

[0165] FIG. 4 shows a shaped balloon envelope in the unfilled state, provided in a particularly advantageous manner for rectal insertion and reliable transanal placement and unfolding of the balloon;

[0166] FIG. 5 shows a modified embodiment of the invention with a catheter shaft waisted in its transanal section;

[0167] FIG. 6 shows a manually operable pump manometer with a pressure scale equipped for multi-stage, sequential filling of the catheter balloon;

[0168] FIG. 7 shows a further modified embodiment of the invention with an infusion container fixedly connected to the catheter shaft and a filling tube for charging the catheter balloon with filling pressure;

[0169] FIG. 7a shows another modified embodiment of the invention where an infusion container is releasably connected to the catheter shaft and can be replaced by another equipment; and

[0170] FIG. 8 shows a pressure decompressing module 37, that once the reflex is released and the bowel begins to contract, fully opens and decompresses the catheter balloon to environment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0171] FIG. 1a shows a longitudinal section through an inflow catheter with a dumbbell- or hourglass-shaped balloon element 2 disposed at the distal end of the catheter shaft 1. The balloon element has, for example, a spherical or discoid expansion at each end. Disposed in the middle region between the terminal enlargements is a cylindrically or approximately cylindrically shaped segment 3 of reduced diameter, which continuously connects the intrarectal enlargement 4 to the preanal enlargement 5.

[0172] The balloon 2 terminally comprises two balloon shaft ends 6, 7 for attaching the balloon to the shaft. During the mounting of the balloon, the shaft ends 6 and 7 are invaginated (inverted) into the inside of the balloon by a defined magnitude B and in this position, in which they are displaced toward each other, are fixed on the shaft 1, for example by gluing or welding.

[0173] The sum of the magnitudes B of the inversions at both ends should be at least equal to the length of the tapered intermediate piece A (A smaller than/equal to the sum of the magnitudes B).

[0174] The inversion depth B at the end of the balloon facing the patient or the rectum corresponds to the distance from the apex 8 of the distal, intrarectal balloon radius 9 to the distal fixation line 11 of the balloon end 6 on the catheter shaft.

[0175] The distal radius 9 corresponds to the frontal radius during free, non-inverted unfolding of the completely filled but not pressurized balloon (broken line). An exemplary rule for geometrically determining the apex 8 to good approximation is illustrated in FIG. 1b. In particular, the drawing shows the two inflection points WP of the longitudinal section through the distal balloon end, which, by the inversion of the distal region of the balloon, result in the spherical or discoid or approximately semitoroidal region of the intrarectal section of the balloon. The normals 9e, 9f to the tangent to the longitudinal section of the balloon intersect with the longitudinal axis X of the catheter shaft at point M, and a circle K around this point M at the distance M-WP yields the forward apex 8, which marks the distal limit for the catheter shaft in its neutral, non-deflected initial position.

[0176] It can be seen in FIG. 1c that a straight line can also be passed through points WP; this straight line represents the plane Z which after invagination of the forward end of the balloon is now tangent distally to the intrarectal portion of the balloon and can also be taken as a measure of the distalmost position of the catheter shaft in its neutral, non-deflected initial position.

[0177] On the side of the balloon facing away from the patient, the inversion depth B corresponds to the distance from the apex 12 of the proximal, preanal balloon radius 13 to the proximal fixation line 14 of the balloon end 7 on the catheter shaft.

[0178] Radius 13 corresponds to the proximal radius when the balloon is freely unfolded without inversion. The geometric determination of apex 12 is similar to the approximation described in FIG. 1b.

[0179] The length of intermediate piece A is determined by determining the distance between the transitions of the shoulder radii 15 and 16 (inflection points) of the mutually facing shoulder surfaces of balloon segments 4 and 5.

[0180] The inversion depths, lengths and distances are each determined in the filled state under filling pressure, the filling pressure being so selected that the balloon unfolds completely but there is no elastic expansion of the balloon envelope.

[0181] The inversion depth B is calculated as follows: B>=A/2 (>=represents greater/equal).

[0182] In mounting the balloon on the catheter shaft, the respective points for the inversion of each of the balloon shaft ends are the apex 8 of the distal, intrarectal balloon radius 9 and the apex 12 of the proximal, preanal balloon radius 13.

[0183] In the embodiment described in this figure, the distal fixation line 11 also corresponds to the distal end of the catheter shaft 1. The shaft terminates directly at the fixation line 11 and does not extend distally past this fixation line in the manner illustrated in FIG. 2.

[0184] FIG. 1b describes the geometric derivation of the apex of the distal balloon radius.

[0185] The forward balloon radius 9, frontally facing the intestinal lumen, of the intrarectal balloon segment 4 is illustrated as a broken line. It is constructed from the two inflection points 9a and 9b and the two inflection tangents 9c and 9d respectively belonging to these inflection points.

[0186] One of the two inflection points 9a or 9b is used to construct a straight line 9e or 9f that is normal to the respective inflection tangent 9c or 9d and intersects the corresponding inflection point 9a or 9b. The point of intersection of these straight lines 9e or 9f with the axis X of symmetry yields the center point of the circle K.

[0187] The circle K, and thus the forward balloon radius 9, results from the center point M of the circle and the inflection points 9a and 9b, which are on the circumference of the circle. In this derivation, apex 8 is obtained from the point of intersection of the circumference of the circle with the axis X of symmetry of the balloon.

[0188] For the description of the frontal apex 8 used below, the derivation of the farthest distally ranging point of the filled, unpressurized balloon envelope is performed, for purposes of simplification, using the point of intersection of the connecting line Z between the two inflection points 9a and 9b with the axis X of symmetry.

[0189] The catheter shaft 1 should be “inflexible”, that means, in case of an axial thrust force onto the catheter shaft upon its insertion into the anus, it should resist any kinking deformation. Furthermore, it should be radially stable, i.e. not allowing for a collapse of the catheter lumen. Additionally, the catheter shaft 1 should resist any twisting or torsion movement. On the other hand, in order to avoid lesions of the bowel wall, the catheter shaft 1 may have a minor ability of an axial bending deformation, but such axial bending ability should be limited, especially to a bending angle of not more than 45° over the entire length of the catheter shaft.

[0190] FIG. 2 shows, by way of example, how sections of the catheter shaft in the form of a tip piece 18 that extend beyond the distal fixation line 11 in a distal prolongation directed toward the bowel are to be considered in determining the inversion depth of the balloon ends 6 and 7, in order to ensure atraumatic inversion, according to the invention, of the distal end of the catheter in the intrarectal balloon during transanal placement of the filled catheter balloon. The length C of the tip piece 18 is defined as the distance from the forward fixation line 11 to the forward apex 19 of the tip piece.

[0191] Length B is increased in comparison to FIG. 1a by the magnitude of length C or C/2.

[0192] The corresponding inversion depth B is preferably calculated taking into account a tip piece in the form: B>=A/2+C.

[0193] Alternatively hereto, the corresponding inversion depth B can, less preferably, be obtained considering a tip piece according to the relation: B>=A/2+C/2.

[0194] FIG. 3 illustrates another, alternative rule for establishing the inversion depth B of the balloon shaft ends 6 and 7 on the catheter shaft 1 in relation to the distal catheter shaft end 11, 19.

[0195] This rule particularly considers a possible axially oriented deflection of the catheter shaft inside the filled, transanally placed balloon. In the context of the inventively described inversion of the balloon shaft ends on the catheter shaft supporting the balloon, such deflection of the shaft in the longitudinal axis could cause the distal end of the catheter shaft to be deflected toward the bowel, thus creating a potential risk of perforation.

[0196] The maximum distal deflection W of the forward fixation line 11 is defined as a distance that emanates from the apex 8 of the radius 9, forming a distally directed prolongation of the longitudinal axis of the shaft, and extends to the apex 20 of a radius 21, said radius 21 being constructed over the largest diameter D of the intrarectal balloon segment 4.

[0197] If the catheter shaft has a tip piece 18 that extends beyond line 11, the maximum deflection path W should be correspondingly selected so that upon maximum deflection W of the shaft, the tip 19 of the tip piece does not extend past radius 21.

[0198] The radius 21 defined by the largest diameter D in the intrarectal balloon segment constitutes a fundamentally relevant boundary line for distal portions of the catheter shaft. In the event of lateral tilting of the shaft longitudinal axis of the transanally placed catheter shaft, the fact that the maximum deflection W is referred to the largest balloon diameter D ensures that the catheter shaft tip (11, 19) still moves within the pivot radius 21 of balloon segment 4, thus preventing relatively well any potential traumatizing contact of the tip with the bowel wall adjacent the balloon.

[0199] In determining the inversion depth B, the particular ratio of the distance W to the radius 21 or of the diameter D on which it is based is preserved and the inversion depth B is adjusted accordingly as necessary.

[0200] FIG. 4 shows the catheter balloon 2 in its emptied form, in which it lies against the catheter shaft ready for insertion in the anus. The envelope segments of the intrarectal balloon 4 and of the middle segment 3 cling to the shaft in folds.

[0201] In this state, the two envelope portions preferably come to lie approximately at the height of the line segment between the fixation points of the balloon ends 6 and 7 on the surface of the shaft. The envelope of the preanal balloon segment 5, by contrast, is preferably smoothed out in the proximal direction and protrudes past the fingers gripping the catheter for insertion, the preferred gripping point being located just proximal of the proximal fixation line 14. The gripping point 22 is preferably implemented as a depression-like receiving surface, one such preferably being provided on each of the opposite, 180°-apart shaft surfaces.

[0202] The evacuated balloon being fixed in such fashion, the user grips with his fingers under the envelope of segment 5, which envelope is smoothed out in a proximal direction, and guides the catheter into the rectum until the gripping fingers abut the external anus. A defined insertion depth is thereby ensured. It is further ensured that the intrarectal balloon section 4 is inserted into the rectal cavity, while the proximal balloon portion 5 comes to lie outside the anus (preanally). Reliable transanal positioning of the catheter therefore occurs as the waisted balloon is filled.

[0203] FIG. 5 shows a preferred implementation of the shaft body 1 that furnishes some degree of automatic positioning and securing of the shaft in the anus even when the catheter balloon has not yet been filled. The shaft 1 has for this purpose a likewise waisted shape, which is correspondingly tapered in the transanal region 23 and in effect locks the catheter shaft in a transanal position in this region after insertion. The catheter shaft preferably also has a distally terminal, funnel-like, atraumatically shaped opening 24 that connects to the duct 25 supplying the medium. In FIG. 5, the balloon 2, 3, 4, 5 is omitted to give an uncovered sight onto the shaft body 1.

[0204] In a particularly large-volume implementation of the intrarectal balloon segment or a longitudinal expansion of the balloon segment that reaches far into the rectum, the balloon segment, in the non-air-filled, ready-to-use state, can optionally be stuffed or packed partially into the opening 24. It then slips out of the opening as the inserted catheter is filled.

[0205] Given suitable implementation of the shaft material, the waist 23 can also predefine a certain kinkability of the shaft body, thus improving its atraumatic properties.

[0206] The filling of the balloon takes place through a separate duct 26 integral to the shaft.

[0207] To prevent backflow of irrigation fluid, the inflow catheter can is [sic] equipped with a non-return valve in the region of the fluid-conveying duct 25.

[0208] The valve can preferably consist of a thin-walled tube element having a wall thickness of few, preferably, 5 to 15 micrometers and the diameter of the duct 25, the distal end of the tube lying freely in the duct 25 over a length of approximately 5 to 10 mm and its proximal end being connected sealingly to the inner wall of the duct 25. As the medium flows through the duct in the direction of the tip, the tube element opens and allows the medium to flow freely. In response to flow in the reverse direction, the tube element collapses and closes up sealingly, preventing an effective backflow.

[0209] FIG. 6 schematically illustrates a pump manometer 27 equipped with a scale 28 suitable for the filling of the inventive catheter balloon in a single step or multiple steps or with a sequential increase in filling pressure. The scale preferably displays, on the one hand, an initial, low pressure range 29 (app. 10-25 mbar), which is set by the user after inserting the catheter and before introducing the infusion fluid, and which, given the inventive preshaping of the balloon envelope and its fixation on the shaft, is sufficient in most cases to ensure transanal anchoring and sealing of the catheter without a direct reflex-triggering effect on the bowel wall.

[0210] When the user then initiates an increase in the filling pressure in the balloon into range 30 (30-60 mbar, with increasing corresponding expansion of the rectal portions of the bowel wall) or into range 37 (60-120 mbar, with increasing additional expansion of the anal sphincter), the user is ultimately able to generate a trigger stimulus of largely reproducible intensity in order to trigger a defecation reflex. The user thus has the advantage of being able to avoid an evacuation reflex in the presence of an initially low balloon pressure merely having an anchoring and sealing action, and thus of being able to retain the infusion fluid in the bowel long enough for his individual needs, resulting in better dissolution or suspension of stool in the fluid. On the other hand, by intentionally causing an increase in pressure in the balloon, he can generate an intense, relatively prompt-acting reflex-triggering stimulus, which can, if necessary, exceed in intensity the triggering effect of a column of colorectal fluid.

[0211] The catheter balloon is preferably filled with air, through a fill line integrated into the shaft wall of the catheter body 1.

[0212] In addition to pressure-controlled filling of the balloon using a pump manometer, as illustrated in FIG. 6, volume-controlled filling can be achieved with the use of an additional syringe element that specifies the preferred fill volume by means of suitable markings on the syringe body. The filling of the balloon is preferably partial, in the form of one-step filling. In the ideal case, therefore, in loose, unexpanded form, the balloon lies against the structures of the bowel and the anus. The balloon envelope thus absorbs the forces acting on the balloon in the rectum, the anus and the preanal region and brings the balloon into the configuration in which it performs the anchoring and sealing function. The respective physiologically acting forces are absorbed by the catheter balloon and thus enable the balloon to be placed anorectally in as pressure-neutral a manner as possible, largely precluding undesired and premature triggering effects.

[0213] A volume-controlled filling of the balloon can also be a two-step process, in which incomplete filling is first performed and the balloon is then, in the second filling step, filled with a volume that has a triggering effect. The pressures developed in the transanal balloon in response to the particular volume should preferably fall within the pressure ranges (29, 30) described in FIG. 6, and are to be determined by and for the user on an individual basis, as in the case of pressure-controlled filling. The manometer can be equipped with a marking function 28a, allowing for marking the individually needed pressure values on the manometer scale.

[0214] To limit the filling pressure or prevent critically high balloon filling pressures, in the case of both manometer- and syringe-actuated filling a pressure limiting valve 31 can be interposed between the filling element and the catheter, to prevent, for example, balloon filling pressures over 120 mbar.

[0215] FIG. 7 shows a preferred embodiment of an inflow catheter, which transitions at the proximal end to two feed conduits that are preferably fixedly connected to the shaft, feed conduit 32 being fixedly connected to a preferably bag-like container 33 containing infusion medium, and thus constituting a ready-to-use unit comprised of catheter and medium.

[0216] The volume of the container 33 must be dimensioned in this case to accommodate approximately 80 to 120 ml of irrigation solution, which would correspond to a so called “mini-enema”. The relatively small quantity is squeezed out manually by the user and thus introduced into the rectum by repeated squeezing. To make it possible to grip the container even with impaired hand motor function, the container is preferably shaped as cylindrical, with a diameter of approximately 4-6 cm.

[0217] Optionally, the connected container takes only 5 to 15 ml of solution, corresponding to a so called “micro-enema”, typically being squeezed out between the thumb and the indicating finger. In order to prevent, that such small volumes are pooling inside the lumen of the irrigating canal, the diameter of the irrigating canal, including the tubing connection 32 and the irrigating canal inside the catheter shaft, is reduced in its dimensions to a volume of equal or less than 1 ml, or preferably less than 0.5 ml of volume, so that the micro-enema reaches the patients rectum without excessive loss inside the device.

[0218] Furthermore, as can be seen in FIG. 7a, connection can preferably be equipped with a seal 35 that can be broken by bending and that releases the irrigation solution. It is also advantageous to provide a non-return valve 36, which is integrated into the fluid-conveying arm of the ready-to-use device and which permits the directed emptying of the container without backflow. The connection optionally ends proximally with a funnel like connector 32a, allowing for a multi-fit connection to a variety of off-shelf, ready to use irrigation solutions.

[0219] Another feed conduit 34 can be connected directly to a filling syringe, a pump manometer or a pressure decompressing mechanism.

[0220] FIG. 8 shows a pressure decompressing module 37, that can be operated as a stand-alone device, or modularly integrated into a pump manometer as pictured in FIG. 6. The module works by e.g. a spring operated opening mechanism, which continuously opens the filling line 34 and the balloon to the ambient environment, fully decompressing the balloon. The threshold for opening the mechanism can be set by user individually to a certain balloon pressure, by an adjustable trigger knob 38. As pictured, the module can be positioned in between the scale and the pump balloon of the manometer. The pressure decompressing module is of particular benefit for e.g. spinal cord injury patients, not being able to sense stool urge or the onset of peristaltic bowel contraction. Once the reflex is released and the bowel begins to contract, the catheter “opens” and can be pulled out or expelled from the rectum.

[0221] The balloon is made from polyurethane material, or from a material with a similar compliance and elasticity characteristics. Preferably, when using polyurethanes, the balloon has a Shore A durometer of 80 to 95, preferably of 80 to 85.

[0222] The wall thickness in the enlarged distal terminal balloon section being adapted to be placed intrarectally is 3 to 6 times thinner than the wall thickness in the tapered balloon section being adapted to be placed transanally, especially 4 to 5 times thinner.

[0223] The wall thickness in the enlarged distal terminal balloon section being adapted to be placed intrarectally is 10 to 30 μm, especially 15 to 25 μm.

[0224] The thickness of the wall in the tapered balloon section being adapted to be placed transanally is 30 to 180 μm, especially 60 to 125 μm.

[0225] The use of only slightly volume-expandable (compliant) materials, such as, for example, polyurethane (PUR), for example of the specification Pellethane 2363 80A to 90A, Lubrizol Corp., is preferred, since these materials have good dimensional stability in the lowest wall thickness range, including as balloon films, in the pressure range of approximately 10 to 120 mbar.

[0226] Such thin-walled PUR balloon films formed into complex shape can preferably be produced by hot molding from previously extruded raw tubing material, which, with suitable stretching of the tube blank before tempering, permits a polymer orientation and lends the shaped balloon films exceptional mechanical strength.

[0227] It is also conceivable to use polyurethanes of low Shore hardness, for example in the range of 60 to 75A, to impart a volume-expandable behavior, with a relative loss of dimensional stability, to the catheter balloon in the wall thickness range of less than 40 μm, and preferably less than 15 μm, in the typical filling pressure range during use of 10 to 120 μm.

[0228] Alternatively, non-volume-expandable, non-elastic materials can be used, such as polyethylene, PVC or mixtures of the aforesaid materials with polyurethane.

[0229] Balloon films according to the invention can also be shaped directly from the extruded, still soft, largely amorphous tube molding compound (in-line molding), in which case the achievable strengths of the films are much lower than those of pre-extruded tubes and the attainable wall thicknesses are much higher than in the case of forming from pre-extruded material.

[0230] Dipping processes using liquid PVC or PUR materials can also be contemplated for production.

[0231] The welding together of single layers of film to form balloon bodies is also conceivable.

[0232] The connection of the balloon to the shaft body is effected by gluing, by thermal methods, or alternatively by shrinking the balloon ends onto the shaft body.

[0233] In the freely unfolded, unpressurized state, the balloon segments, in the unpressurized state, should have diameters and length dimensions of: [0234] intrarectal: measuring a diameter of 40 to 80 mm, preferably 50 to 70 mm, measuring a length of 30 to 60 mm, preferably 35 to 45 mm; [0235] transanal: measuring a diameter of 10 to 35 mm, preferably 20 to 25 mm, measuring a length of 20 to 50 mm, preferably 25 to 35 mm.

[0236] In addition to the transanal use of the inflow catheter, the embodiments according to the invention can also be used for placement of a transanally inserted drainage tube for, among other purposes, the ongoing drainage of stool from a patient's intestine. Further, the described catheter technique may also be contemplated for use in surgically created stomata/openings or other natural body openings.