DE102018103618A1 - stent - Google Patents

Abstract

The invention relates to a stent for introduction into a hollow organ of the human and / or animal body, preferably in the gastrointestinal tract, in particular the intestine, with a hose-like hollow body open at the axial end. According to the invention it is provided that the hollow body has an outer wall and an inner wall, wherein in a space between the outer wall and the inner wall, a support system for stabilizing the shape of the stent is provided.

Description

The invention relates to a stent for introduction into a hollow organ of the human and / or animal body, preferably in the gastrointestinal tract, in particular the intestine, with an axially end open tubular hollow body.

A stent is implanted as an implant in the medical field in the human or animal body and serves there on the one hand to dilate vessels and hollow organs and keep open to counteract, for example, after an infarct situation of vasoconstriction. On the other hand, another area of application of stents is in the sealing of leaks, especially in hollow organs such as the intestine or the esophagus. Such leaks (anastomoses) may occur, for example, as a complication following a surgical procedure in the gastrointestinal tract. Due to the often associated with an anastomosis outlet of the organ contents into the abdominal cavity, it usually leads to serious infections and an abscess formation, especially if intestinal contents exits. This is especially for patients in a postoperative situation of high danger.

To seal such unwanted anastomoses stents are used for a long time, lining the hollow organ in the anastomosis in the form of a tube. Such stents are often self-expanding. The problem with known stents of the aforementioned type, however, is that they must be anchored in the surrounding tissue in order to prevent slippage or spontaneous leakage of the stent. The mechanical means commonly used for this, such as hooks or the like, pose a high risk of injury to the patient. In order for movements of the patient or the organ itself - for example as a result of normal peristalsis - the stent remains securely fixed and ensures a seal of the anastomosis, appropriate fixatives must be provided in sufficient numbers and with sufficient anchoring potential. Here, however, there is the great difficulty to find a compromise in which despite secure fixation of the stent irritation or even injury to the surrounding tissue is avoided by a too deep intervention or cutting the fixative.

Furthermore, a dense contact of a tubular or tubular stent to the irregularly shaped inner wall of a hollow organ such as the intestine is usually not 100% or at least not permanently to ensure.

Against this background, the object of the present invention is to overcome the abovementioned disadvantages and to provide a possibility of securely sealing an anastomosis in a hollow organ, the treatment being intended to be associated with the least possible impairment for the patient and low costs.

The above object is achieved by a stent having the features of the subject of claim 1. Advantageous developments are the subject of the dependent claims.

The stent according to the invention has a tubular or tubular shape, which is also the basis of known stents. The continuity of the organ thus treated is therefore not affected. A high dimensional stability and compared to the prior art known stents improved attachment to the irregularly shaped inner wall of a hollow organ, such as the intestine, and thus a successful and permanent sealing of an anastomosis is achieved according to the invention by a support system which in a double-walled outer shell of a embedded in the tubular body of the stent forming hollow body. The fundamentally arbitrarily shaped and application-specific selected support structure of the support system prevents collapse of the stent by itself or due to external pressure.

An inner wall separating the support structure from the lumen of the hollow body of the stent provides a first seal against the escape of organ contents through the support structure in the region of the anastomosis. A further sealing of the relevant hollow organ is further achieved by the outer wall of the hollow body, with which an abutment against the inner wall of the hollow organ is achieved. Preferably, the gap between the inner and the outer wall of the hollow body, in which the support system is located, the end face sealed against ingress of organ content. Due to the double-walled design of the hollow body shell is thus both outward, i. for the treatment of the anastomosis, ie also reached inward, so that no organ content can fix in the support structure and is prevented from further transport.

Due to its advantageous properties, the stent according to the invention is also particularly suitable for use in anastomosis prophylaxis or can be applied during and after the healing of an anastomosis for a certain time without problems for temporary protection against recurrence of anastomoses.

The sealing function and the required mechanical stability are thus associated with the stent according to the invention thus two separate structures, namely the tubular hollow body on the one hand and the support system on the other. As a result, the structure of the stent is simplified and the production costs are significantly reduced compared to known stents.

For the construction of the support system support rings are particularly suitable, which surround the lumen of the hollow body radially. Assuming sufficient rigidity, support rings in the shell prevent the hollow body as such from collapsing or deforming in any other undesirable manner, thereby disturbing the sealing of the anastomosis. The use of support rings makes it possible to achieve a comparatively simple and therefore cost-effective design of the support system. First, support rings need only be arranged in a sufficiently small axial distance from each other to develop a certain support effect. However, a complete radial sheathing of the lumen with support material over the entire length of the hollow body is not necessary. On the other hand, the inner wall and the outer wall of the hollow body in the stent according to the invention of inexpensive materials can be produced in a simple manner. For example, in particular a polymer layer or a polymer tube can be produced by standard methods such as casting or by extrusion with low production costs.

In an elastic training further advantages are given in relation to the system of the stent to the organ wall and thus the seal. Therefore, preferably, at least one support ring made of an elastic material, in particular an elastic plastic, or comprises an elastic material, in particular an elastic plastic, on.

In addition, the inner wall and / or the outer wall may consist of a plastic or have a plastic. The inner and / or outer wall is also preferably elastic, so that on the one hand the shape of the stent is given by the support system and the stent can also adapt to the shape of the surrounding hollow organ.

In conjunction with an elastic outer wall of the hollow body, a corrugated outer profile of the outer surface of the hollow body is produced by a support system with support rings. This improves the fixation of the stent in the desired area. In particular, the risk of slippage of the stent along the hollow organ or even spontaneous stent exit is further reduced. Compared with sharp-edged fixatives, such as hooks, the fixation of the stent but this is done in extremely tissue-conserving manner.

Particularly advantageous is an embodiment of the support system with support rings, in which at least in a part of the support rings, an inner cavity is provided, which is preferably filled with a fluid. Preferably, an air filling is used here. According to the invention, however, other gases and / or liquids are suitable for filling the cavity. About the internal pressure of the cavities, the shape or size and / or the rigidity of the support rings can be selected.

By using an elastic material for the support system or the support rings, the production costs for various types of support systems or support rings can be further reduced. It is then sufficient, for example, initially to produce only one type of support rings in terms of material selection and shape and to give the support ring its final size, shape and strength by adjusting the internal pressure of the cavity by filling with more or less fluid before the Cavity is sealed. In this way, different types and forms of support systems can be offered with support rings without having to set up a separate production line for each variation.

In a particularly preferred embodiment of the stent according to the invention, the support rings are fluidly connected to each other. The fluidic connection between the support rings can be realized by one or more axial channels. The channels can be made of the same material as the support rings or of another material. The course and the arrangement of the channels can also be carried out in any desired manner. In particular, an arrangement parallel to the longitudinal axis of the hollow body is not required. Due to the fluidic connection, it is possible in principle to achieve a compensation with respect to the filling quantity or the internal pressure of the support rings over the entire support system. In this way, the homogeneity in terms of deformability, rigidity and thus the ability to adapt the shape of the hollow body or the stent is increased to a predetermined by the hollow organ shape.

Particularly flexible and easy to use is an embodiment of the stent according to the invention, in which the support system, in particular the support rings, is or are designed such that by supplying or discharging a fluid, ie for example air, the shape and / or size of the Support system and thus the hollow body or the stent can be changed as such. By a corresponding supply line, which preferably extends from the stent to outside the body of the patient and is connected to the fluid chambers of the support system, can be easily by connecting a pressure control, such as in Form a pump, increase or decrease the internal pressure in the support system. As a result, the stent can also be subsequently expanded and / or deflated. In this way, a treating physician is given far-reaching opportunities to take appropriate measures in the event of a change in the clinical situation of the patient.

In addition, a stent with the aforementioned properties is to be implanted in a comfortable way. The stent may first be transported through the hollow organ to the site affected by an anastomosis. To attach to the wall of the organ, the stent can then be expanded by increasing the pressure in the support system, i. be blown up, so to speak. The expansion of the stent takes place at any time in a controllable manner and may also be canceled, reversed and / or repeated. This is a significant advantage over conventional, self-expanding stents that do not usually offer this capability.

The stent according to the invention is advantageously also easy to implant by means of standard colonoscopes and / or by means of a circular stapler.

Preferably, the outer and / or inner wall of the hollow body is formed at least partially permeable to fluids and / or solids. The outer wall is perforated for this purpose in particular in a corresponding manner. According to the invention, a semipermeable formation of the outer wall can also be provided. A permeability can therefore also be given only in a direction of passage and / or selectively only for certain substances. In this way, leaked organ contents or other liquids can enter the hollow organ through the shell of the hollow body, but is prevented from further or re-emergence.

In the space between the inner and the outer wall of the hollow body, a porous material may be provided which surrounds the other support system and supports in its effect or even form the support system. The material in the space may alternatively or additionally be plastically and / or elastically deformable. As a result, the investment of the hollow body of the stent is improved to the inner wall of the organ and increases the sealing effect of the stent for the treatment of an anastomosis. In conjunction with an at least partially permeable outer wall of the hollow body, a porous material in the hollow body shell also serve to receive liquid from the organ wall and to some extent self-absorbed organ organine content and / or bind.

A particularly preferred embodiment of the stent provides that the outer wall of the hollow body is at least partially permeable to fluids and / or solids, while the inner wall of the hollow body is impermeable and thus the lumen of the hollow body with respect to the outer area, i. the area in which the outer wall, the space between the walls and the support system are located seals. In conjunction with an optionally provided porous material in the intermediate space according to the preceding section thus material from the environment of the stent, in particular also leaked organ contents, can be recorded and bound in the shell of the hollow body, but without a permeability between the lumen of the hollow body and the Appearance point of the anastomosis or the environment of the hollow organ would be given, which allows leakage of organ content.

Improved absorption and binding of material outside the hollow body of the stent can be achieved by subjecting the intermediate space between the outer wall and the inner wall to a negative pressure. For this purpose, the stent can have a vacuum line, via which a negative pressure generated in the intermediate space of the hollow body shell of the stent by means of a corresponding device, for example a vacuum pump, is brought into effect. By a negative pressure relative to the prevailing pressure in the vicinity of the hollow body material, in particular possibly already leaked organ contents, sucked through a correspondingly permeable outer wall formed in the stent and preferably transported away from the intermediate space via the vacuum line. The risk of infection, for example due to leaked intestinal contents in the abdominal cavity, is thus effectively reduced. Another advantage of a negative pressure in the hollow body shell is that by the suction effect to the outside a closer and thus denser system of the hollow body takes place against the inner wall of the hollow organ.

A vacuum line can be passed through the inner wall of the hollow body at a correspondingly sealed passage or connection point and passed through the lumen and the hollow organ to the outside of the body of the patient, where it is accessible, for example, for medical personnel. It is understood that a negative pressure in the space between the walls basically independent of any pressure setting in the support system to the Expansion or deflation can be realized or can be adjusted.

To aid treatment, the stent may also contain or have an active agent released at a corresponding site in the hollow organ into which the stent is implanted. Such an active ingredient may have, for example, a healing-promoting, anti-inflammatory, analgesic and / or antiseptic action. A particularly advantageous possibility of introducing an active substance by means of the stent according to the invention consists in an at least partial coating of an outer side of the outer wall of the hollow body. In this way, a targeted, local action of the active substance can be achieved at the site affected by an anastomosis.

The dimensions of the stent according to the invention are ideally adapted to the anatomy of a hollow organ to be treated. In particular, the length of the hollow body can be chosen almost freely in the construction of the stent according to the invention. Preferably, the outer diameter or the luminal diameter of the hollow body is on average between 10 mm and 60 mm, preferably between 15 mm and 40 mm, particularly preferably between 20 mm and 30 mm. However, the abovementioned values represent only preferred dimensions in which the stent according to the invention in the state of use corresponds to an average anatomy of the human or animal body. By an elastic design of the shell of the hollow body or the support system, the size and shape can also be changed in particular subsequently and as needed, so that it is possible to deviate from the aforementioned values, without departing from the scope of the invention.

The invention will be explained in more detail by means of exemplary embodiments. In this case, all described and illustrated features in each case as belonging to the present invention, regardless of their combination in the examples shown or the reference back in the claims.

• 1 eine schematische Längsschnittdarstellung einer bevorzugten Ausführungsform eines erfindungsgemäßen Stents,
• 2 eine schematische Querschnittsschnittdarstellung des Stents von 1,
• 3 eine perspektivische schematische Darstellung einer bevorzugten Ausgestaltung eines Stützsystems eines erfindungsgemäßen Stents und
• 4 eine schematische Längsschnittdarstellung einer möglichen Anwendungssituation für den erfindungsgemäßen Stent.

It shows

• 1 a schematic longitudinal sectional view of a preferred embodiment of a stent according to the invention,
• 2 a schematic cross-sectional sectional view of the stent of 1 .
• 3 a perspective schematic representation of a preferred embodiment of a support system of a stent according to the invention and
• 4 a schematic longitudinal sectional view of a possible application situation for the stent according to the invention.

1 shows a particularly preferred embodiment of a stent according to the invention 1 , The main body of the stent 1 is through a hollow body 2 educated. The hollow body 2 has a tubular or tubular shape, with an elongated, approximately cylindrical lumen 3 ,

The shell of the hollow body 2 has a multi-layered, in particular elastic, construction. An inner wall 4 of the hollow body 2 surround the lumen 3 radial. In the embodiment shown here, the inner wall 4 formed liquid and gas-tight and thus seals the lumen 3 from the outer areas.

The hollow body 2 also has an outer wall 5 on, which is at least partially porous in the present example. It is thus a passage of liquid, gaseous and / or solid material through the outer wall 5 to some extent possible.

Between the inner wall 4 and the outer wall 5 of the hollow body 2 there is a gap 6 , In the space 6 there is a support system 7 which is the stent 1 or the hollow body 2 gives a desired shape and stability in this form.

The support system 7 includes in the preferred embodiment shown here a plurality of support rings 8th that the lumen 3 of the hollow body 2 surrounded radially. The support rings 8th prevent collapse or collapse of the hollow body 2 at external pressure. The support system 7 ensures in particular by the support rings 8th thus for the maintenance of the lumen 3 , The support rings 8th do not have to be arranged equidistant as shown, but may also be more or less tightly and / or arranged at different distances from each other depending on demand.

In the present case, the support rings 8th an internal cavity 9 on, which is filled with a fluid, in particular air. Due to the internal pressure in the cavity 9 get the support rings 8th From an elastic material ultimately their shape, size and strength against mechanical deformation and give the hollow body 2 his form to be achieved.

The support rings 8th or the cavities 9 the support rings 8th are in fluid communication with each other. The fluidic connection between the support rings 8th is present in the form of axial connecting channels 10 realized. About the channels 10 can be a pressure balance between the cavities 9 different support rings 8th respectively. Preferably, therefore, all cavities form 9 the support rings 8th along with the connection channels 10 a common fluid system of the support system 7 ,

Via a supply line 11 For example, a fluid can be supplied to the fluid system and / or the fluid contained can be partially or completely drained off. It is thus possible over the supply line 11 the support system 7 and thus the hollow body 2 as such in its shape and / or size change. A change in size and / or shape can in particular also be carried out after implantation in the relevant hollow organ of a patient. For this purpose, the supply line runs 11 preferably to the outside of the body of the patient. About a not shown in detail pressure change device, such as a pump or the like, the stent can be 1 selectively and controllably expand and / or deflate.

In the space 6 between the inner wall 4 and the outer wall 5 of the hollow body 2 is in the present embodiment further provided a moldable and porous, ie spongy and / or foam-like material. Due to this material is an improved system of the hollow body 2 allows for an irregular surface.

Due to the absorbent properties of the porous material can through a permeable outer wall 5 Substances, in particular liquids, from the environment of the stent 1 be recorded and bound.

In the particularly preferred embodiment of the stent according to the invention shown here 1 is also an evacuation of the gap 6 between the outer wall 5 and the inner wall 4 possible with the porous material therein. The evacuation, ie an admission of the gap 6 with a negative pressure relative to the environment of the hollow body 2 , is present via a vacuum line 12 possible, via a junction 13 through the dense inner wall 4 with the gap 6 connected is.

The vacuum line 12 is preferably accessible by being guided to the outside of the body of the patient. There, a device for generating a negative pressure, ie a vacuum pump or the like, which is not shown in detail, are connected. In this way, an already implanted stent 1 be easily activated and deactivated in relation to the evacuation function. It is possible by means of an evacuation in the sense described above, even larger amounts of material from the environment of the hollow body 2 take up, bind and / or carry away.

In 2 is a cross section of the in 1 in longitudinal section shown stents 1 shown. The section selected for the display is made according to the in 1 dash-dotted line indicated II , In the illustration according to 2 is the multi-wall construction of the shell of the hollow body 2 with an inner wall 4 and an outer wall 5 and a gap between them 6 clearly. Furthermore, the arrangement of the axial connection channels 10 at several positions along the circumference of the hollow body 2 clear. It is understood that of the number and arrangement of the connection channels shown here 10 within the scope of the invention can be deviated readily. In particular, an equidistant arrangement or a uniform distribution on the circumference of the hollow body 2 not required and / or there may be a greater or lesser number of connection channels 10 be provided.

The support system 7 is in isolated form, ie without further elements of the hollow body 2 , in particular without the inner wall 4 and the outer wall 5 and the porous material in the space 6 between the walls 4 . 5 represented. In this illustration, the support rings 8th as well as the axial connection channels 10 recognizable. In the illustration according to 3 run the axial connection channels 10 - different than in the illustration according to 2 - In three (instead of four) straight lines along the longitudinal extent of the hollow body 2 , It is understood that an arrangement of channels 10 in another way and in particular a different number of connection channels 10 can be provided.

In particular, according to the invention, it is not necessary that a connecting channel 10 between two support rings 8th exactly in imaginary extension of another connection channel 10 between two other support rings 8th runs. Furthermore, the connection channels 10 also in a non-parallel manner to one another and / or to the longitudinal axis of the hollow body 2 run. It is thus according to the invention, for example, a spiral shape of the connecting channels 10 or even an overall spiral formation of the support system 7 possible.

The embodiments presented here are expressly not restrictive to the scope of the invention.

In 4 is an example of a typical application situation for the stent according to the invention 1 shown. The stent 1 is in the example shown in the intestine 14 implanted in a patient and dresses it in the area of an anastomosis 15 out and seal the intestine 14 against the escape of intestinal contents 16 from. In the in 4 This situation is already part of the intestinal contents 16 through the anastomosis 15 in the environment of the intestine 14 , ie into the abdominal cavity, leaked. The stent according to the invention 1 now prevents further leakage of intestinal contents 16 ,

At the same time achieving a good sealing effect by means of the stent according to the invention 1 in the area of the anastomosis 15 is the continuity of the intestine 14 continue to maintain. It is thus when using the stent according to the invention 1 For example, it is not necessary to provide an artificial bowel outlet that is associated with significant patient disability and discomfort for the patient. The intestinal contents 16 can largely unimpeded the stent 1 or the hollow body 2 through its lumen 3 happen axially. It can be seen that the hollow body 2 due to the elastic inner wall 4 and in particular the elastic outer wall 5 the shape of the intestine 14 adapts easily and fits tightly to the intestinal inner wall 17 invests.

The support rings 8th generate on the elastic outer surface of the hollow body 2 ie on the outer wall 5 , a surface profile in the form of a corrugated structure. By the thus obtained outer shape of the hollow body 2 push this with its outer wall 5 in the area of the support rings 8th each slightly more on the intestinal wall 17 and push it a little bit. This will cause the stent 1 Fixed in position stable at its predetermined location and secured against accidental slipping.

By a not shown in detail drug coating on the outside of the outer wall 5 of the hollow body 2 For example, healing the injured wall of the intestine 14 be supported or accelerated.

The hollow body 2 has a luminal diameter of about 25 mm in the present example. Ultimately, however, the invention covers stents 1 with a structure according to the invention regardless of the diameter, the length and / or the other proportions.

Although in the embodiments presented here, a plurality of features are shown implemented together, each feature is taken in isolation as an independent aspect of the invention and can ultimately be realized in any combination with other features or in isolation, without departing from the scope of the invention.

LIST OF REFERENCE NUMBERS

1

stent

2

hollow body

3

lumen

4

inner wall

5

outer wall

6

gap

7

support system

8th

support ring

9

cavity

10

connecting channel

11

supply

12

Vacuum line

13

junction

14

intestine

15

anastomosis

16

tract

17

Intestinal inner wall

Claims (10)

Stent (1) for introduction into a hollow organ of the human and / or animal body, preferably in the gastrointestinal tract, in particular the intestine (14), with a hose-like hollow body (2) open at the axial end, characterized in that the hollow body (2) has a inner wall (4) and an outer wall (5), wherein in a space (6) between the inner wall (4) and the outer wall (5) is provided a support system (7) for stabilizing the shape of the stent (1). Stent after Claim 1 , characterized in that the support system (7) has a plurality of radial support rings (8), preferably wherein the support rings (8) at least partially an inner, preferably with a fluid, in particular air, filled cavity (9). Stent after Claim 2 , characterized in that the support rings (8) in particular by at least one particular axially extending connecting channel (10) are fluidly connected to each other. Stent according to one of the preceding claims, characterized in that the Support system (7), in particular the support rings (8), is designed such that it can be changed by supplying or discharging a fluid, in particular air, in its shape and / or size. Stent according to one of the preceding claims, characterized in that the outer wall (5) of the hollow body (2) at least partially permeable to fluids and / or solids, in particular perforated, and the inner wall (4) of the hollow body impermeable, semi-permeable or permeable for fluids and / or solids. Stent according to one of the preceding claims, characterized in that in the intermediate space (6) between the inner wall (4) and the outer wall (5) is provided a porous, in particular a sponge-like and / or foam-like material. Stent according to one of the preceding claims, characterized in that the hollow body (2) is formed such that the intermediate space (6) between the inner wall (4) and the outer wall (5) of the hollow body (2) with a negative pressure relative to the Ambient pressure of the hollow body (2) can be acted upon. Stent according to one of the preceding claims, characterized in that the outer wall (5) has at least partially an active substance coating on an outer side. Stent according to one of the preceding claims, characterized in that at least one support ring (8) consists of an elastic material, in particular an elastic plastic, or an elastic material, in particular an elastic plastic, and / or that the inner wall (4) and / or the outer wall (5) consists of a particular elastic plastic or has a particular elastic plastic. Stent according to one of the preceding claims, characterized in that the outer diameter or the luminal diameter of the hollow body (2) is on average between 10 mm and 60 mm, preferably between 15 mm and 40 mm, preferably between 20 mm and 30 mm.

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