WO2012129587A1

WO2012129587A1 - Mechanical device for temporarily closing the intestine

Info

Publication number: WO2012129587A1
Application number: PCT/AT2012/050041
Authority: WO
Inventors: Georg Bischof
Original assignee: Georg Bischof
Priority date: 2011-03-31
Filing date: 2012-03-30
Publication date: 2012-10-04
Also published as: AT510401A4; AT510401B1

Abstract

The invention relates to a mechanical device for temporarily closing the intestine of a mammal, comprising a supporting frame (2), which can be changed between a relaxed or folded state and a stretched or unfolded state and which comprises one or more tensioning elements (2') for tensioning a membrane (3) fastened to the tensioning elements, the membrane being substantially impermeable to liquids and solids, wherein the device can be transported to the location of the planned intestinal closure by means of an endoscope (1).

Description

Mechanical device for temporarily closing the intestine

The invention relates to mechanical devices for temporarily closing the intestine of a mammal.

Endoscopy is a diagnostic procedure that has been established for many decades in human and veterinary medicine. The endoscopes used for this purpose have evolved continuously and nowadays not only allow simple illumination and imaging of the interior of the body, e.g. using fiber optic fibers, but are also equipped to perform minimally invasive surgical procedures. For example, modern endoscopes include, in addition to fiber optics, air insufflators or gas pumps, irrigators, aspiration pumps, and flexible tools, such as, e.g. Needles for injection, gripping or cutting tools or wire electrodes for coagulation with electric current. To introduce the equipment required for the respective intervention, the endoscope has several channels.

Especially in the case of enteroscopic surgery in the intestines of humans and animals, despite prior administration of laxatives, complications frequently occur due to the chair passing the test site to be examined and / or surgically treated, which not only complicates and delays the procedure, but in the case of operative Interventions, eg for tissue removal or removal, also represents an infection risk for the patient. Thus, it would be desirable to be able to temporarily close the intestine during an endoscopic procedure. The present inventor has previously described in a prior art application (AT A 25/2010 and PCT / AT201 1/000015) a solidifiable chemical composition for producing a transient occlusion of the intestine. In addition to this chemical solution of the above problem, it would be desirable to have a mechanical solution available.

Above all, inflatable balloons are known from the prior art. In particular, JP 2000-023909 discloses a balloon catheter which can be introduced into the channel of an endoscope and conveyed together with the endoscope to the desired location, where it is inflated and thus temporarily closes the intestine. US 4,776,845 also describes an inflatable device, however, for occluding the intestinal exit to prevent leakage of intestinal contents, especially during colonoscopy. The occlusion is forcibly downstream of the colonoscopic examination site and the endoscope is inserted into the colon through a tightly sealed channel in the middle of the device.

US 2009/157161 A1 describes a device for removing two-way shape memory stents from a "tubular organ" comprising an inflatable balloon above which a cold fluid is introduced which causes a stent located there to collapse. to be removed from the organ. Optionally, a second balloon is provided and the cold liquid is passed between the two balloons. As examples of the organ, blood vessels and the bile duct, but not the intestine, are called.

US 2010/298773 A discloses a device for cleaning u.a. of the intestine, consisting of a cleaning head which can be inserted into a channel of an endoscope, wherein from openings on the sides of which a liquid conveyed through the channel of the endoscope can be injected to the intestinal wall and sucked off again. During the suction process, a temporary closure of the intestine may occur. Also, US 2007/015965 A1 describes a cleaning device for preparing the colon for colonoscopy, but the device does not occlude the colon but, on the contrary, is intended to eliminate potential blockages therein. The guide tube for the device is changeable between a rigid and a flexible state.

The above-mentioned embodiments using balloons are disadvantageous in that a balloon can slip along the moist intestinal wall and away from the desired site of application, and moreover provides scarcely sufficient sealing action to prevent passage of fecal fluid. To counter this, the balloon would have to be greatly expanded to be close to the balloon The intestinal wall to lie, but it can lead to excessive stretching of the intestinal lumen.

The object of the invention was therefore to provide a device for producing a transient intestinal occlusion, which stably remains at the desired position during an endoscopic procedure and, in this state, tightly seals the intestine against feces.

DISCLOSURE OF THE INVENTION

This object is achieved by the present invention by providing a mechanical device for temporarily occluding the mammalian intestine, comprising a support frame which is changeable between a collapsed and a deployed state and which comprises tensioning elements for tensioning a membrane attached thereto, for liquids and solids are substantially impermeable, the device being transportable by means of an endoscope to the site of the planned intestinal obstruction.

When used, such a device according to the invention can seal the intestine tightly by means of the tensionable membrane, wherein the tensioning elements can be adapted exactly to the width of the intestinal lumen at the respective site and are thereby secured against slipping without damaging or excessively damaging the intestinal wall. Apart from the endoscope itself, which is required for the endoscopic procedure, no additional aids are required to transport the device to the intended site of use.

In preferred embodiments, substantially the entire device in the relaxed or folded state of the support frame in a channel of the endoscope can be accommodated so that the transport through the intestine can be done using the endoscope in a simple, rapid and gentle for the patient. The strained membrane preferably has a substantially circular or elliptical shape, which further improves the adaptation to the intestinal lumen and further reduces the risk of damage to the intestinal wall. The clamping elements of the support frame are preferably spokes or struts, by means of which the membrane taut and, the intestinal lumen at the respective point, can be tightly tensioned. More preferably, the spokes or struts cooperate with the membrane attached thereto such that the strained membrane has a screen or funnel shape when the spokes or struts have been deployed or unfolded. By such a convex or concave curvature of the membrane, even with larger amounts of feces striking the membrane can not produce a sufficiently large pressure to move the device from its position. The spokes / struts are particularly dimensioned so that they can be accommodated in the relaxed state as a bundle in the channel of the endoscope.

As an alternative to the embodiments with spokes or struts, however, the support frame can also be designed as a grid tube or stent which can be unfolded in the intestine to a diameter corresponding to the intestinal lumen or slightly exceeding the lumen in order to form the occlusion with the membrane stretched between them. some meshes of the mesh serve as tensioning elements. The unfolded, close to the intestinal wall tight fitting provides in this case a particularly good protection against slipping. The membrane may be attached either at one of the ends or in the middle of the tube. The first case has the advantage that the flaccid membrane in the unfolded state of the stent does not have to come to lie within the grid, but can protrude from this and thus does not increase the diameter. The diameter of the stent / grid tube is again preferably chosen so that it can be introduced into the channel of the endoscope in the unfolded state.

As a further alternative, the support frame may also be a deformable ring, on the inside of which the membrane is fastened. The ring, which serves as a single clamping element as a whole, is again preferably accommodated in the channel of the endoscope. In particularly preferred embodiments of the invention, the material of the support frame has elastic or pseudoelastic material behavior (hereinafter both referred to as "elastic" for the sake of simplicity) and / or shape memory, and the transition of the support frame from relaxed to folded or folded The unfolded state and / or vice versa is triggered by a change in the environmental conditions, preferably by a change in pressure or temperature.

Under elastic material behavior is to understand herein that the support frame has a bias that dissolves when used in the intestine by the frame unfolds or spans when there is no pressure acting thereon.

Preferred embodiments of the invention which function according to this principle are, for example, curved metal spokes / struts that are combined to form a bundle of parallel metal rods under an external pressure within the endoscope channel. When pushed out of the channel, in the unpressurized state, they again assume the curved state, thereby tensioning the preferably attached in the region of their ends membrane, which - depending on the radius of curvature of the spokes or struts - can assume a screen or funnel shape.

Also an elastic ring with membrane on its inside works on this principle. The ring is deformed under pressure and stabilized in a compressed state by either being inserted into the channel of the endoscope or wrapped with a retaining means such as tape or wire. In this state, it is transported to the desired site of use where, by pushing out of the channel or severing the holding means with a cutting tool at the end of the endoscope, it recovers to its original annular state, whereby the membrane tensions and forms the occlusion. A third example of the principle of elastic material behavior is a stent of classical construction, ie a "folded" lattice tube held under pressure in a tube or hose that spontaneously expands when it is pushed out of the tube unfolds, thereby attaches itself to the intestinal wall and closes the lumen with the membrane stretched between them.

Although such an elastic material behavior in the broadest sense could also be understood as "shape memory", in the narrower sense "shape memory effect" refers to embodiments of shape memory alloys or plastics in which the material of the support frame is imprinted with a specific shape "but the frame is fixed in a different form. Especially with temperature change, but under certain circumstances also with hydration, the fixation is overcome, and the frame takes on the impressed shape.

In the case of shape memory alloys, in particular the ^nitinol® (ie nickel-titanium) common for stents, but also, for example, certain copper-zinc, copper-zinc-aluminum, copper-aluminum-nickel or iron-nickel-aluminum alloys, This transition is due to the change in the crystal structure of the alloy as a function of the ambient temperature and is sometimes even reversible (one- or two-way shape memory). Latest shape memory polymers work on the same principle, while already known representatives are consistently mixtures of several polymers, one of which served to fix the other. That is, a polymer is embedded in a resiliently deformed state into a solid matrix of a natural or synthetic wax (or other similar low-melting material) and returns to its original state upon melting of the matrix. The latter polymers inevitably have only one-way shape memory.

For the present invention shape memory alloys or polymers with shape memory in question, the state change takes place when heated above about 30 ° C. Such materials are used according to the invention especially for support frames in Gitterrohr-, ie stent or ring form. In the case of a two-way shape memory, the support frame only needs to be cooled below the corresponding temperature again to remove the device and remove the intestinal occlusion, for example as described in the introduction in connection with US 2009/157161 A1, and can thus be used. together with the endoscope are removed from the intestine. This can be done in a channel of the endoscope or outside, for example by means of a mounted at the end of the endoscope gripping tool.

Although support frames with elastic spokes or struts as tensioning elements can likewise be produced from materials with shape memory, for economic reasons it will be preferable to simply pull these frames back into the endoscope channel. For this purpose, the clamping elements at the non-membrane-carrying end with a flexible rod, by means of which they were previously pushed out to clamp the membrane from the channel, be firmly connected. By applying tensile force to this rod, then the clamping elements fold back together and find again recording in the endoscope.

When self-deploying stents are used as support racks that have only one-way shape memory, they may be provided at one end with similar "spokes" over (and over a similar flexible rod as described above) from outside the endoscope a tensile force is transferable to the stent. This tensile force causes the stent to fold back up, detach from the intestinal wall, and be removed from the intestine. Embodiments of the invention with an annular support frame can also be easily cut for removal with a cutting tool of the endoscope and pulled out of the intestine with a gripping tool.

In preferred embodiments, at least the support frame, more preferably the support frame and the membrane, the device according to the invention consists of biodegradable, in particular resorbable, material. In this way, after completion of the endoscopic procedure, the device can be easily inserted Be left behind intestine, where it preferably within a few hours, more preferably within 30 to 90 minutes, begins to dissolve and so no obstacle to the intestinal passing fecal matter represents more. Since the patient normally undergoes the endoscopic examination in the fasting state, the dissolution of the material within this period need not necessarily be completed, since - depending on the position in the intestine - it may take several hours, until after the examination taken in food components the Untersu - Passing or intervention point happen. Such biodegradation may be due to the action of the intestinal secretion produced at the site in question, or the trailing fecal flow, or both. The effect of the intestinal secretion can be split to both the pH, by the acid-labile, more rarely basal-labile, bindings, as well as the enzymatic environment in each section of the intestine go back.

The degradation is most preferably a more complete, i. After a relatively short time, there are no solid residues that would have to be forced out of the intestine by the subsequent feces stream. In particular, the degradation products are at least partially absorbable via the intestinal wall, i. they contain ingredients of the food.

Such biodegradable materials exist in large numbers. Examples include natural and synthetic polymers, such as vinyl esters of fatty acids, amino acids or fruit acids, for example of lactic acid, citric acid or tartaric acid. These result in the polymerization derivatives of polyvinyl alcohol, which are cleavable by acid or base action and / or esterases to polyvinyl alcohol (PVAL) and the corresponding acid. PVAL is a non-toxic polymer, which is also commonly found in drug formulations, and is excreted without damage to the body, and the acid, such as a fatty, amino or fruit acid, can be absorbed. When aspartic acid or citric or tartaric acid or similar polycarboxylic acids are used, their di- or trivinyl esters - alone or in addition to monovinyl esters - are used, which serve as crosslinking agents. Further examples are modified representatives of natural polymers, such as, for example, polypeptides, polysaccharides and the like, in particular, for example, vinyl oxycarbonyloxy derivatives of gelatin, hyaluronic acid or glycogen, ie carbonic acid monovinyl esters - for example those of free OH, NH or NH ₂ groups in the polymer - which by decarboxylation are easily cleavable in PVAL and the corresponding natural polymer.

Furthermore, polymers and especially copolymers of lactic and glycolic acid are mentioned, which begin to dissolve rapidly on contact with water or aqueous solutions and which, with simple control of the monomer ratio, both relatively rigid and relatively flexible materials can represent, which both The support frame and the membrane may consist of substantially the same basic materials.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail below with reference to the accompanying drawings, of which Figs. 1 to 5 show schematically simple embodiments of the device according to the invention, wherein the dimensions of the parts shown do not necessarily correspond to those in reality.

In particular, Fig. 1 shows an embodiment of the device in which the support frame consists of several - here in fact five - spokes or struts as clamping elements 2 ', between which a membrane 3 is attached. The frame is practically completely in a channel 4 of an endoscope 1 housed and transported to the desired location in the intestine. By means of a (not shown) flexible rod, which is preferably fixedly connected to the ends of the clamping elements, the frame can be pushed out of the channel. Reference numeral 5 denotes a second channel of the endoscope 1, in which usually (not shown) fiber optics is housed. The clamping elements 2 ', which are preferably made of metal or plastic, as mentioned above, a curved basic shape was impressed, which they can not occupy within the endoscope, but are substantially parallel to each other. By embossing either a bias in an elastic see material or a real shape memory in a shape memory alloy or a shape memory plastic is generated. In both cases, the spokes / struts 2 'bend during or immediately after pushing out of the endoscope 1, whereby the membrane 3 spans therebetween. This curvature is thus triggered either by the elimination of the pressure on the elastic clamping elements 2 'or by the temperature change, ie heating, in the intestine. A curvature due to elasticity in this case is preferable to a true shape memory, as this allows a more accurate adaptation to the width of the intestinal lumen by the clamping elements 2 'are more or less pushed out of the endoscope channel 4. Such an embodiment can be easily used for different intestinal regions with different widths of the intestinal lumen.

In Fig. 1, a state is shown in which the membrane has not yet fully unfolded or stretched. Upon further pushing out of the channel 4 there is an additional expansion and tension of the membrane until it completely fills the intestinal lumen and closes. The clamping elements 2 ', which then rest against the intestinal wall, are rounded for this reason at their ends, as indicated in Fig. 1 by means of spherical ends in order to avoid injury to the intestine.

After completed endoscopic surgery, the device via the flexible rod can be easily pulled back into the channel 4 and removed together with the endoscope from the intestine. Figs. 2 and 3 show an alternative embodiment of the device according to the invention, in which the support frame consists of a ring 2, on the inside of which the membrane 3 is attached. The ring 2, at the same time the only clamping element ment, can be housed in compressed or folded state wholly in the channel 4 of the endoscope. Also, this embodiment of the device is pushed out of the channel 4 with a flexible rod (not shown), and similarly as before, the ring 2 unfolds on or after exiting due to elasticity or true shape memory and thereby biases the membrane.

Fig. 2 shows a state in which the ring 2 with the membrane 3, which is also folded, as indicated by wavy lines, already half out of the endoscope is pushed out. In this case, it is a ring of a shape memory alloy or a shape memory plastic, which is why no change in shape has occurred. Once the ring 2 completely leaves the endoscope and reaches the required temperature, e.g. has heated in the range of 30-35 ° C, the material is in the embossed state, i. assumes a substantially circular shape or an elliptical shape, thereby tensioning the membrane 3. The strained ring 2 is then aligned with the end of the endoscope to close the intestinal lumen.

Fig. 3 shows an embodiment of the ring 2 made of an elastic material without shape memory, which must be kept for this reason by two holding means 6 in a compressed state. After transport of such an embodiment to the desired location in the intestine - within or in whole or in part outside the endoscope - the holding means are severed, eg with a cutting or pinching tool housed in a channel of the endoscope. As a result, the ring 2 jumps into a substantially circular or elliptical shape and in turn stretches the membrane 3. The diameter of the ring 2 is to be selected corresponding to the respective intestinal lumen, which means that rings of different sizes are preferably provided in a set. Embodiments of the invention with a ring as a support frame are preferably made of biodegradable, in particular also resorbable, material, as described above, whereby they after completion of the endoscopic Can be left behind in the intestine. Alternatively, the ring may be grasped and pulled out of the intestine with a grasping tool, such as biopsy forceps, as is standard on endoscopes. Due to the round shape there is no risk of injury to the patient in this case.

Referring now to Figures 4 and 5, there is schematically illustrated a third embodiment of the device according to the invention, in which the support frame 2 comprises a stent, i. a lattice tube, wherein the dashed line indicates the longitudinal or rotational axis of the stent. In Fig. 4, this stent 2 carries a membrane 3 at one end and is shown in a deployed state. As mentioned above, the stent can be made to fold and / or unfold by mechanical action, elasticity, or shape memory.

The dimensions in FIG. 4 do not necessarily correspond to reality, since a stent 2 as a carrier frame should also be able to be accommodated essentially entirely in a channel of the endoscope. Therefore, it should not exceed a diameter of about 3-5 mm in the unfolded state. In the deployed state, however, the membrane 3 must close a gut lumen of several centimeters, for which a strong shortening and simultaneous expansion of the diameter of the stent 2 are required. In order not to have to transport a stent several tens of centimeters long in the folded state along the intestine, which would place high demands on the flexibility and elasticity of the stent material, the length of the unfolded stent 2 is preferably smaller than its diameter, as in FIG. 5 is shown in several schematic side views.

The membrane 3 can be fastened, preferably glued or welded, near one end of the stent 2, as shown in FIG. 5a, in the middle of the stent 2, as shown in FIG. 5b, or directly at the end, as shown in FIG. 5c. be. The variant from FIG. 5 c is particularly preferred, since the membrane 3 can come to lie outside the grid during folding of the stent 2, so that it does not increase the diameter of the folded stent. For example, the membrane for this purpose can also be fixed to the outer edge of the grid tube. Similar to rings as carrier racks, the stents according to the invention are also adapted to the width of the intestinal lumen at the point of use, so that in turn stents with different diameters are preferably provided in a set.

Embodiments of the invention with a stent as a support frame are particularly preferably made of a biodegradable and in particular resorbable material, since the removal of the stent would otherwise be associated with an increased effort; e.g. as described in US 2009/157161 A1. When using a material that will be within a short time, e.g. within a few hours, dissolves, as stated above, only needs to be pierced or pierced with the endoscope after the end of the investigation or surgery, the membrane. The support frame and the membrane, which is preferably also degradable, later go at least partially naturally and / or are at least partially resorbed via the intestinal wall.

The material of the membrane 3 is preferably a plastic, as described above, particularly preferably a material which is at least slightly stretchable from the stent 2 as a support frame during its deployment in order to close the intestinal lumen tight. As non-limiting examples, polymers crosslinked with carbonate ester moieties are vinyloxycarbonyl-modified natural products, e.g. Gelatin or polysaccharides, which also have good biodegradability and resorbability.

The invention thus provides various embodiments of a device for producing a temporary intestinal obstruction, which are characterized by relatively simple construction, accordingly cost-effective production and easy handling and thus represent a valuable addition to the prior art.

Claims

1 . A mechanical device for temporarily occluding the mammalian intestine, comprising a support frame (2) changeable between a collapsed and a deployed state and comprising one or more clamping elements (2 ') for tensioning a membrane (3) attached thereto which is substantially impermeable to liquids and solids, the device being transportable by means of an endoscope (1) to the site of the planned intestinal obstruction.

2. Apparatus according to claim 1, characterized in that the substantially entire device in the relaxed or folded state of the support frame in a channel of the endoscope (1) can be accommodated.

3. Apparatus according to claim 1 or 2, characterized in that the tensioned membrane (3) has a substantially circular or elliptical shape.

4. Device according to one of claims 1 to 3, characterized in that the clamping elements (2 ') of the support frame (2) spokes or struts.

5. Apparatus according to claim 4, characterized in that in the unfolded or deployed state of the spokes or struts (2 ') attached thereto, the tensioned membrane (3) has a screen or funnel shape.

6. Device according to one of claims 1 to 3, characterized in that the support frame (2) is a grid tube, at the end of the membrane (3) is fixed.

7. Device according to one of claims 1 to 3, characterized in that the support frame (2) is a deformable ring.

8. Device according to one of the preceding claims, characterized in that the material of the support frame (2) has elastic or pseudoelastic material behavior and / or a shape memory and the transition of the support frame (2) from the relaxed or folded in the clamped or unfolded state and / or inversely triggered by changing environmental conditions.

9. Apparatus according to claim 8, characterized in that the environmental conditions to be changed from pressure and temperature are selected.

10. Device according to one of the preceding claims, characterized in that it consists at least partially of biodegradable, preferably resorbable, material.