Patent Application
20230041626
The invention relates to a method and a device for filling an inflatable catheter balloon of a device for transanally introducing an infusion into the rectum or colon of a patient by means of a filling device, more particularly to a method and a device for intermittently triggering a coordinated defecation reflex in the rectum or colon of a user with an individual anatomy of the rectum or colon and a current reflex status.
Catheters for transanally administering an infusion into the straight intestine (rectum) or large bowel (colon) of a patient have been known in a wide variety of embodiments for many years.
Inflow catheters can be implemented as simple tube elements, but for improved retention of the catheter in the rectum they are also provided with an intrarectally placed balloon element. Such balloon elements provide, in addition to an anorectally anchoring function, a certain sealing effect that retains in the bowel the fluid that has been introduced by the irrigation. The sealing capacity of inflow catheters fitted with an exclusively intrarectal balloon component is inadequate in many cases, however, and must be created by the user by continuously manually repositioning the surfaces of the sealing balloon on the floor of the rectum or manipulating the position of the catheter shaft atop the balloon.
A major risk associated with the use of ordinary commercial catheters that are inserted transanally in the bowel continues to be perforation of the bowel wall due to improper handling or the presence of previously injured or similarly weakened bowel wall structures. Such perforations of the intestine have been preventable heretofore only by suitable education and sensitization of the user with respect to this particular set of problems.
Over the past ten years, a novel infusion technology that goes beyond the use of conventional transanal infusions has become established; in this new approach, the reflex-coordinated, active evacuation of the rectum and large portions of the left colon adjoining the rectum is triggered by intermittent, relatively small-volume, intrarectally introduced infusions. By consistent voiding of these segments of the intestine, the patient can thus be brought to a state of so-called “pseudo-continence” regardless of existing incontinence problems. The so-called transanal irrigation (TAI) method can be performed by the patient himself.
The function of the rectally instilled infusion medium, apart from some degree of mobilization of stool, is primarily to moderately expand the lateral wall portions of the rectal ampulla (the terminal rectum), which then results in the triggering of the physiological stool evacuation reflex (reflex triggering). Whereas the rectally placed infusion medium usually causes such reflex triggering within a few minutes, it can take much longer, up to 30 minutes or more, for the administered irrigation volume to be fully voided from the rectum or colon. The relatively long time required for TAI limits its acceptance by many patients, and often rules this method out despite the fact that it is, as a rule, efficient for use by the individual.
Another problem is that many users are not able to manually bring irrigation catheters of conventional design into an adequately sealing position and keep them there.
Furthermore, as the balloon component of a conventional catheter is expanded inside the rectum, a reflex-triggering expansion of portions of the bowel wall can occur when the filling process has only just begun, thereby leading, inter alia, to a reflex-like opening of the anus and thus sometimes causing the anchoring balloon to slip out of the rectum.
Another disadvantage of such a prematurely triggered reflex, which shall be called a pathological reflex, against a coordinated physiological reflex is that the latter begins at the upper arch of the descending colon and then transports the intestinal contents from there downwards to the sigmoid colon and from there to the rectum, from where it is finally drained through the anus. After such a coordinated physiological reflex, the descending colon, sigmoid colon and rectum is entirely empty, and the user is pseudo-continent for the following hours. Compared to this, a pathological reflex is not coordinated and therefore does not transport the intestinal contents towards the rectum and anus, and as a consequence, the the user is not pseudo-continent afterwards.
Furthermore, commercially available devices for intermittent transanal irrigation, such as, for example, Peristeen Anal Irrigation, made by Coloplast, Denmark, are of relatively elaborate design, and are often only conditionally suitable for use outside the patient's familiar domestic surroundings.
To improve user acceptance of transanal irrigation, a catheter technique would be desirable which, once the catheter shaft is inserted in the rectum, holds it in its transanal position without the need for continuous repositioning, and both keeps the body of the shaft from sliding on into the bowel, with potentially traumatic consequences, and reliably prevents the catheter from accidentally slipping out of the anus prematurely.
Greater convenience in terms of the transanal placement of the catheter is offered in this regard by inflow catheters having a double balloon arrangement. Here, two separate balloon elements, which are usually filled simultaneously via a single filling lumen, are mounted in spaced relation on the catheter shaft. These come to lie on both sides of the anal canal, i.e. the internal and the external, thus mutually taking on the structures of the anus. When the wall of the balloon is expanded under pressure, the usually elastic implementation of the balloon material brings about a spherical enlargement of the balloon bodies and thus a certain axially exerted squeezing of the anus disposed between the balloon bodies. The dislocation-proof positioning of the catheter shaft obtained with such catheters can be assumed to be relatively reliable. A problem resides in the sometimes high filling pressures needed for the elastic expansion of the envelope, which are felt by patients as an uncomfortable or even painful foreign body sensation. Further, the elastic expansion of the intrarectal balloon to a tightly filled sphere can lead to direct triggering of the defecation reflex, which, in turn, in the presence of simultaneous rectal contraction and declining sphincter muscle tone, will in the most unfavorable case cause the catheter to slide out and the irrigation fluid to be voided prematurely.
DE 10 2004 033 425 B4 describes a sealing system for the management of rectal or anal incontinence having a particular embodiment for the tamponade of bleeding hemorrhoids, presenting a waisted balloon element having a terminal intrarectal or preanal section. The balloon envelope of the device is placed on the balloon-supporting shaft body in such a way that during the filling process, the intrarectal balloon segment moves in the direction of the rectal floor and there exerts a tamponade pressure on the bleeding venous blood vessels. The preanal balloon segment concurrently moves toward the external anal opening. The result is a tamponade effect oriented axially to the anus from both sides. In addition to the axial tam ponade of the bleeding, the middle, waisted section of the balloon expands outward radially to the wall of the anal canal. It is preferably shaped with a diameter that exceeds the diameter of the opened anal canal. In the described device for the acute management of venous anorectal bleeding, in the in-use state the tip of the shaft body protrudes freely and unprotectedly into the intestinal lumen and poses a potential risk of injury.
WO 2007/118621 A1 describes a similar dumbbell- or hourglass-shaped balloon sealing system. The object there is to provide a seal against involuntary leakage of stool for intermittent periods of a few hours in chronically anorectally incontinent patients. This managing device also prominently features the rolling movement of the terminal balloon segments from both sides axially toward the anus. Here again, in the transanally placed state, the tip of the shaft body supporting the balloon protrudes freely and potentially traumatizingly into the intestinal lumen.
Both devices describe an hourglass- or dumbbell-shaped balloon configuration, the anus being received in the waisted region of the balloon, i.e. the region that is tapered relative to the terminal portions thereof. Such shaping of the balloon not only results in relatively good securing of the catheter against dislocation, due to the sealing of the balloon inside the anal canal on all sides, but also makes for a considerable improvement in sealing performance over that of conventional double balloons. In addition, both devices make it possible to largely avoid any expansion of the balloon envelope that could trigger irritation, pain or a defecation reflex, since the balloon wall is preferably already shaped to a reference dimension or beyond. Thus, the filling or unfolding of the balloon to its reference state requires only a low filling pressure, equal to or only slightly greater than the pressure prevailing in the rectum or abdomen at the time.
Nevertheless, a particular disadvantage of the embodiments described in DE 10 2004 033 425 B4 and WO 2007/118621 A1 has proven to be that the distal tip of the shaft body supporting the balloon becomes freely exposed during the filling process and protrudes into the intestinal lumen, potentially causing irritation or injury to the bowel wall there during use.
The same problem occurs at the closure system for managing rectal or anal incontinence disclosed in the US 2007/0 123 661 A1. At this document, even the distal-most balloon is fixed to the catheter shaft in a rather big distance from the distal tip of the catheter shaft, so that—if the distal-most balloon is not urged towards the distal tip of the catheter shaft, this tip is not protected by the catheter balloon from injuring the intestinal mucosa. Furthermore, all balloons which are disclosed in this document and are intended to be placed inside of the rectum or colon of a user are designed with a rather longitudinal shape, where the distance from the radial-most extension of the balloon to the lateral surface of the catheter shaft is smaller than the axial dimension of the balloon.
Therefore, such a balloon is not capable of producing a force onto the lateral colon wall of the user, but develops upon inflation in an axial direction from the rectum towards the colon of the user.
The arrangement disclosed in the WO 2008/103 788 A1 suffers from the same disadvantage. This document describes a seal for a rectal or ostomy appliance. At this document, the envelope of the catheter balloon is fixed at three fixation points, namely (i) in the area of the rectum, the distal end of the tubular balloon envelope is fixed to the catheter shaft itself, (ii) in the preanal region, the the proximal end of the balloon envelope is fixed to at a flexible rear wall of the device, and (iii) at an area between these two fixation points, an intermediate portion of the balloon envelope is fixed for a third time, namely to the catheter shaft in the area of the anus. Such a third fixation point reduces the capability of the balloon to move freely along the catheter shaft in order to center and seal the balloon in the area of the anus or rectum. But what is much worse, the balloon balloon is not capable of producing a force onto the lateral colon wall of the user, but develops upon inflation in an axial direction from the rectum towards the colon of the user. Finally, this balloon is made of an elastic material and therefore does not show any wrinkles as it is placed inside the rectum, even if it is not inflated, when it is rather small and contracts towards the catheter shaft, as this balloon is not preshaped to a reference volume corresponding to the rectum or colon of a user.
The document UA 68 194 A refers to a method for treating inertness of the rectum. The former arrangement known from this document does neither comprise a catheter nor a tubular or annular balloon fixed to such catheter at two fixation points. Instead, this document discloses a first ellipsoid balloon for placement in the rectum and a second balloon for placement in the anal canal. Both balloons are spaced apart from each other for about 2 cm. The rectal balloon is made of elastic thin latex rubber, which is a rather compliant material and can be blown up to an unlimited volume, thereby potentially inducing serious injuries to the user. Therefore, such equipment cannot be used by the user himself, but only by skilled personnel. Furthermore, this method is not used for triggering a coordinated physiological reflex in order to empty the descending colon, the sigmoid colon and the rectum, but it is used only for training of the contractile activity of the colon. For this purpose, the pressure in the balloon is varied with a frequency of 3 to 6 times per minute. So, a single pressure pulse is only 5 seconds in case of a frequency of 6 times per minute for a whole pressure cycle, up to 10 seconds in case of a frequency of 3 times per minute for a whole pressure cycle. Even if a defecation reflex would be triggered by such a short pressure pulse, it would not lead to a coordinated physiological reflex which would be able to empty the descending colon, the sigmoid colon and the rectum. Instead, such short pulses would only lead to the aformentioned pathological reflexes which are not able to clean the descending colon, the sigmoid colon and the rectum. Moreover, the rectal balloon has a ellipsoidal shape, but no discoidal shape. Therefore, the influence on the lateral walls of the rectum is weakened as the balloon “escapes” the rectum in the axial direction towards the colon, especially due to a missing catheter shaft which would otherwise define a constant length of the balloon and promote a more radially expansion of the balloon in case of its inflation.
Finally, the WO 2009/144 028 A1 discloses a device for a drainage of stool from the colon of a patient. There, a catheter shaft is missing, too, and therefore, the balloon will attain a more axial shape than a discoidal shape upon inflation, and for this reason, the influence on the lateral walls of the rectum is rather weak.
Another disadvantage of such a prematurely triggered reflex, which shall be called a pathological reflex, against a coordinated physiological reflex is that the latter begins at the upper arch of the descending colon and then transports the intestinal contents from there downwards to the sigmoid colon and from there to the rectum, from where it is finally drained through the anus. After such a coordinated physiological reflex, the descending colon, sigmoid colon and rectum is entirely empty, and the user is pseudo-continent for the following hours. Compared to this, a pathological reflex is not coordinated and therefore does not transport the intestinal contents towards the rectum and anus, and as a consequence, the the user is not pseudo-continent afterwards.
The problem initiating the invention is to eliminate these disadvantages of the known prior art.
This problem is solved, in an arrangement of the cited species, by virtue of the fact that a catheter shaft is provided as well as a catheter balloon in the form of an endless cut, that is an annual or tubular cut with only two circularly extending edges which afterwards form ends tapering to the shaft dimension of the catheter shaft supporting the balloon, and which are fixed on the preferably outer jacket surface of the catheter shaft, preferably in a simply invaginated or inverted manner.
By doing this, a catheter is provided, the catheter comprising:
VUDL>VREF.
Two fixation pointes on a catheter shaft, the distal one thereof near the distal tip of the catheter shaft can provide the balloon with a rather stable axial dimension, so that it is able to expand primarily in a radial direction. This feature can be promoted, if the wall thickness in the area near the ends of the balloon is greater than in an intermediate area between both fixation points, or if both flanks of the balloon extend from one of both fixation points towards a more edge-like periphery without a cylindrical section between both flanks of the balloon, so that the inflated balloon adopts a discoidal shape with a peripheral edge surrounding the catheter shaft in a maximum distance.
With such a device being provided, the following steps can be carried out.
In a first step, inserting the catheter in the rectum or colon of the user and providing an initial fill volume VIF,1 or an initial filling pressure pIF,1 of air or another fluid in the catheter balloon in order to inflate the catheter balloon below the reference dimension VREF of the balloon filling volume VBF thereof in a pressure-neutral manner, i.e. wherein the initial filling pressure pIF,1 inside the catheter balloon is equal to a physiologically acting intra-rectal acting pressure pIR that is prevailing in the rectum of the user, producing a sealing and anchoring effect without any stretching of the envelope of the catheter balloon and causing neither a trans-mural pressure pTM,1 beyond the physiologically intra-rectally acting pressure pIF nor a reflex triggering expansion of portions of the lateral rectal wall exposed to the catheter balloon, according to the following formulas:
pIF,1=pTM,1=pIR,
and wherein the initial fill volume VIF,1 of the catheter balloon is below the reference dimension of the balloon filling volume VREF:
VIF,1<VREF,
so that the envelope of the balloon is not stretched; and in a second step, increasing such initial fill volume VIF,1 or such initial filling pressure pIF,1 to an increased fill volume pIF,2 or an increased filling pressure pIF,2 by pumping, squeezing or injecting air or another fluid into the catheter balloon by the user until there occurs a gradual, user-controllable expansion of portions of the lateral rectal wall exposed to the catheter balloon in such a way that the degree of filling of the balloon is best adapted to the individual anatomy, allowing for an even distribution of the trans-mural pressure pTM,2 exerted by the balloon onto the exposed rectal structures, gradually increasing from the physiologically acting intra-rectal pressure pIR to a force level suited for triggering a coordinated physiological defecation reflex of the individual user, according to the following formula:
pIF,2=pTM,2>pIR,
and wherein the increased fill volume VIF,2 of the catheter balloon is still below the reference dimension of the balloon filling volume VREF:
VIF,2<VREF,
so that the envelope of the balloon is not stretched.
Wheras the first step only serves the purposes to center the balloon in the rectum and to seal the balloon in or against the anus, in the second step, the pressure is raised a little, in order to generate a moderate trans-mural pressure slightly beyond the intra-rectal pressure which does not trigger a reflex at once. In stead, such a pressure level slightly raised above the intra-rectal pressure is kept constant for about 1 minute to several minutes, typically for 1 minute to 5 minutes, or for 2 minutes to 5 minutes, and within this waiting time, the rectum slowly establishes a coordinated physiological reflex, which is able to clear the descending colon, the sigmoid colon and the rectum from the intestinal contents. There shall be no fluctuations within this waiting time of about 1 minute to 5 minutes. Instead, the constant pressure level shall simulate a gradual increasing of the filling of the rectal ampoule in order to trigger a coordinated physiological reflex with a sufficient force to empty the descending colon, the sigmoid colon and the rectum.
The different pressure levels are defined as follows:
The balloon filling pressure pBF is the pressure inside of the catheter balloon which can be influenced by pumping air or another fluid into the balloon or by emptying the balloon gradually by opening of a valve, and which can be measured by a manometer which can be integrated with a pump. It should be noted, that the pressure pBF is also influenced by shifting air or another fluid into the balloon with a syringe. The only difference of these two methods is that by a pump, the pressure is directly controlled, whereas by use of a syringe, a predefined volume of air or liquid corresponding to the fill volume of the syringe is shifted into the balloon. Therefore, the first method is addressed as a pressure-controlled filling method, whereas the second method is addressed as a volume-controlled filling method, also bot filling methods affect both the filling pressure pBF as well as the fill volume VBF of the balloon.
While the balloon filling pressure pBF is the pressure at the inner surface of the balloon envelope, the trans-mural pressure pTM is the pressure at the outer surface of the balloon envelope. If the balloon envelope is not stretched, both pressures are equal to each other:
pBF=pTM.
On the other hand, if the balloon envelope indeed is stretched, the trans-mural pressure pTM is not equal to the balloon filling pressure pBF anymore, but is reduced by the tensioning force in the balloon envelope. Then, the relation is:
pBF>pTM,
although the trans-mural pressure pTM increases, too, if the the balloon filling pressure pBF is raised.
Furthermore, the intra-rectal pressure pIR is the physiological pressure exerted in the rectum by the body or, respectively, anatomy of the user, in a similar way as the intra-abdominal pressure inside the abdomen of the user. This pressure is not affected, neither by the trans-mural pressure pTM nor by the balloon filling pressure pBF.
As the envelope of the catheter balloon is not completely unfolded to the reference dimension VREF of the balloon filling volume, neither in the first step nor in the second step, it is wrinkled in all these steps. Only in case of a maloperation, that is if the user inflates the balloon beyond its preshaped reference dimension VREF, the wrinkles disappear at the envelope. In order to prevent injuries of the user in case of such a malopertion, the envelope is made of a material which achieves a rather unvarying dimension VUDL, where any further expansion comes to a stop.
In many cases, it has proven to be advantageous, if the triggering effect can be increased by filling a liquid irrigation inflow fluid directly into the rectum of the user via a central lumen of the catheter shaft, which is open at both ends of the catheter shaft. Preferably, this can be done between the first and the second step of the method according to the invention. The additionally poured in liquid irrigation inflow fluid assists the fill volume inside the balloon in triggering a coordinated physiological emptying reflex.
To prevent, insofar as possible, lesions due to the tip of the shaft, the invention describes a specific, particularly advantageous ratio of the length of the middle, waist-like balloon segment to the invagination (inversions), on both sides, of the fixation points of the ends of the balloon shaft to the catheter shaft. This ratio ensures that in the filled, transanally positioned state, the tip of the catheter shaft spontaneously retracts into the intrarectal balloon segment and is nestled atraumatically there. The atraumatic securing of the catheter tip inside the intrarectal balloon segment is also ensured according to the invention when the shaft axis undergoes the deflections inside the anal canal that typically occur during use, of the kind readily caused by a tug or push on the tube connection through which the catheter is guided in.
The invention further addresses the problem of preventing undesired or premature triggering effects due to the filled balloon as it unfolds in the rectum. Triggering of the defecation reflex can be prevented in most cases by preshaping the balloon to the reference dimension or beyond (residual dimensioning), since the filling pressures necessary for anchoring and sealing the catheter are largely the same as, or need be only a few millibars higher than, the pressures prevailing in the rectum or in the abdomen. The atraumatic securing of the tip of the catheter in the region of the intrarectal balloon segment is ensured even at such low filling pressures of, for example, 10 to 25 mbar.
Shaping the balloon to its reference dimension further makes it possible for the user, by increasing the filling pressure or fill volume of the balloon from the initial filled state in which the balloon primarily has a sealing and anchoring effect, to induce a well-controllable and gradually increasable expansion of the bowel wall adjacent the catheter balloon, ultimately leading to controlled triggering of the defecation reflex with individually adjusted intensity.
In addition to the initial expansion of the wall of the rectum, a further suitable increase in the filling pressure in the dumbbell-shaped, waisted catheter balloon additionally causes a dilation of the anus or the anal sphincter, constituting another efficient trigger stimulus.
The intensity of such pneumatic expansion of the bowel wall or the anus can substantially exceed the intensity of reflex-triggering expansion with fluid media. Due to the more intense stimulus, several sequentially occurring cycles of evacuation reflexes can be triggered even though the stimulation is given only once.
This pneumatic expansion stimulus that can be well controlled by the user can also reduce the necessary amount of infusion fluid in many cases, which in turn can considerably shorten the time needed to evacuate the infusion from the rectum, thereby ultimately opening up the method to many users as a therapeutic option for self-administration.
The optional combined pneumatic/liquid triggering of reflexes described here eliminates the need for elaborate technical implementation of irrigation appliances, since in the preferred use case the necessary irrigation volume can be kept so small that it can be connected directly, as a compact, ready-to-use solution, via a fixed feed conduit to an inflow catheter designed according to the invention, and thus, in an ideal manner, be used as a disposable product.
For this purpose, the irrigation solution is preferably filled into a cylindrical, bag-like container, which the user can conveniently introduce intrarectally by squeezing it out with the hand.
The inflow catheter according to the invention further comprises a preferably fixedly glued-in filling conduit for charging the catheter balloon with filling pressure. The unit for filling the balloon is preferably implemented in reusable form, and can be configured as a hand-operated pump balloon connectable via a coupling, or alternatively a pumped balloon with a pressure-indicating manometer. Alternatively, volume-controlled filling of the balloon is also conceivable. Regardless of the filling arrangement, the user can determine by stepwise approximation the degree of filling of the balloon that is optimal for him, that which is best adapted to his individual anatomy and his current reflex status.
To ensure the most practicable catheter insertion possible and the reliable transanal placement of the tapered portion of the dumbbell-shaped balloon element, the catheter shaft is preferably equipped in the proximal, preanal region with gripping depressions to accommodate the fingers gripping the catheter during insertion. If the user has no sensitivity in the pelvic or anal region, he guides the catheter in with his fingers until they abut the anus, and can thus avoid uncontrolledly deep insertion.
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:
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.
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).
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.
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
It can be seen in
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.
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
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.
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.
The inversion depth B is calculated as follows: B>=N2 (>=represents greater/equal).
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.
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
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.
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.
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.
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.
In a preferred, particularly thin-walled and soft-film-like implementation of the balloon body, the two segments move toward each other in response to the slightest, nearly ambient filling pressure and roll over the middle segment 3. When the two segments are in contact in the region of the transition points (15, 16) of the shoulder radii, the apex 8 of the radius 9 is flush or nearly flush with the distal fixation line 11 of the distal balloon shaft end 6 on the catheter shaft.
A configuration of this kind would correspond in situ to a clinical use situation in which the anal canal was maximally shortened in length. Even in this extreme case, it would thus be ensured by virtue of the described inversion rule that the free distal catheter shaft end, which here corresponds to the distal fixation line 11, does not extend into the intestinal lumen and even in the event of maximal lateral deflection of the catheter shaft in the rectum (tilting of the intrarectal portion of the shaft toward the bowel wall) does not come into contact with the wall of the intestine and pass beyond the distal balloon radius 9, as a maximum limit precluding irritation and lesions of the bowel wall.
The mere individual intra-abdominal pressure bearing against the transanally placed balloon or acting on the balloon is sufficient to produce a combined transanal sealing effect, comprised of radial sealing with respect to the anal canal and axially oriented sealing brought about by the counter-rolling movement of the terminal balloon enlargements at the inner and outer outlets of the anus. The sealing effect thus is not contingent on the balloon initially being filled beyond its volume and unfolding freely until the balloon envelope begins to expand. The balloon can behave in the described axial counter-rolling and radial unfolding fashion, even under partial filling of, for example, 70 to 90% of its volume when freely unfolded on the catheter shaft. This enables the balloon catheter to be placed in the anus in a nearly pressure-neutral and irritation-free manner.
In the presence of normal or slightly modified anal anatomy, any traumatizing effect of the tip of the catheter shaft on the bowel wall can thus be precluded, even under completely pressure-neutral charging with a filling medium, by the inversion of the shaft tip that occurs according to the invention.
Length B is increased in comparison to
The corresponding inversion depth B is preferably calculated taking into account a tip piece in the form: B>=A/2+C.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
The filling of the balloon takes place through a separate duct 26 integral to the shaft.
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.
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.
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.
The catheter balloon is preferably filled with air, through a fill line integrated into the shaft wall of the catheter body 1.
In addition to pressure-controlled filling of the balloon using a pump manometer, as illustrated in
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
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.
The volume of the container 33 must be dimensioned in this case to accommodate approximately 80 to 120 ml of irrigation solution. 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.
Connection 32 is preferably 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.
Another feed conduit 34 can be connected directly to a pump manometer 27 or a filling syringe.
The balloon element 2 consists of a thin-walled soft film in the wall thickness range of 5 to 100 micrometers. Films in the thickness range of 5 to 40 micrometers are advantageous. Wall thicknesses of 5 to 15 micrometers, on the other hand, are particularly preferable.
The use of only slightly volume-expandable materials, such as, for example, polyurethane (PUR), for example of the specification Pellethane 2363 80A to 90A, Dow Chemical 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.
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.
It is also conceivable to use polyurethanes of low Shore hardness, for example in the range of 60 to 75 A, 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.
Alternatively, for example non-volume-expandable materials can also be used, such as polyethylene, PVC or mixtures of the aforesaid materials with polyurethane.
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.
Dipping processes using liquid PVC or PUR materials can also be contemplated for production.
The welding together of single layers of film to form balloon bodies is also conceivable.
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.
In the freely unfolded, unpressurized state, the balloon should preferably have a diameter of approximately 30-60 mm in the intrarectal section 4, approximately 10 to 30 mm in the middle, waisted region 3, and approximately 30-50 mm in the preanal region 5. The middle segment 3 should have a length of approximately 20-40 mm and each of the terminal segments 4 and 5 a length of approximately 20-40 mm.
If, as a special measure for sequential filling, the catheter balloon is provided with optional intrarectal balloon triggering, the intrarectal balloon section 4 in the freely unfolded, unpressurized state preferably has a diameter of approximately 40-80 mm and a length of preferably 30-60 mm.
In addition to the transanal use of the inflow catheter, the embodiments according to the invention can also be used for perforation-safe 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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2011 111 225.5 | Aug 2011 | DE | national |
| 10 2011 118 943.6 | Nov 2011 | DE | national |
| 10 2011 121 202.0 | Dec 2011 | DE | national |
| 10 2012 005 607.9 | Mar 2012 | DE | national |
| 10 2012 008 361.0 | Apr 2012 | DE | national |
This patent application is a continuation-in-part of pending prior U.S. patent application Ser. No. 16/026,669, filed 3 Jul. 2018 by Fred Gabel for METHOD FOR INTERMITTENTLY TRIGGERING A REFLEX-COORDINATED DEFECATION (Attorney's Docket No.: KUCH-59 DIV), which patent application is a division of prior U.S. patent application Ser. No. 14/239,991, filed Feb. 20, 2014 by Fred Gabel for TRANS-ANAL INFLOW CATHETER AND METHOD FOR INTERMITTENTLY TRIGGERING A REFLEX-COORDINATED DEFECATION (Attorney's Docket No. KUCH-59), which in turn is a 371 national stage entry of International (PCT) Patent Application No. PCT/EP2012/003535, filed Aug. 20, 2012 by Fred Gabel for TRANS-ANAL INFLOW CATHETER AND METHOD FOR INTERMITTENTLY TRIGGERING A REFLEX-COORDINATED DEFECATION, which patent application in turn: (i) claims benefit of prior German Patent Application No. 10 2011 111 225.5, filed Aug. 20, 2011; (ii) claims benefit of prior German Patent Application No. 10 2011 118 943.6, filed Nov. 21, 2011; (iii) claims benefit of prior German Patent Application No. 10 2011 121 202.0, filed 12/16/2011; (iv) claims benefit of prior German Patent Application No. 10 2012 005 607.9, filed Mar. 22, 2012; and (v) claims benefit of prior German Patent Application No. 10 2012 008 361.0, filed Apr. 25, 2012. The eight (8) above-identified patent applications are hereby incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14239991 | Jun 2014 | US |
| Child | 16026669 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16026669 | Jul 2018 | US |
| Child | 17967242 | US |
