Suction stent

Abstract

The present invention relates to a stent for introduction into a hollow organ of a human or animal patient, particularly the gastrointestinal tract. The stent may be used, inter alia, to provide vacuum sealing of leaks in specific anatomical regions within the hollow organ, for example, for the treatment of localized anastomotic failure. Accordingly, a stent (10) for introduction into a hollow organ of a human or animal body, preferably the gastrointestinal tract, particularly the intestine, is provided. The stent (10) comprises a stent body having a wall (12), preferably radially elastic, defining an internal fluid passageway (14) from one end of the stent body to the opposite longitudinal end of the stent body, and a porous elastic layer (16) covering the outer surface of the wall (12) around its entire circumference and along a predetermined longitudinal cross-section of the stent body. The porous layer (16) covers the outer surface of the wall (12) around its entire circumference and along a predetermined longitudinal cross-section of the stent body. The porous layer (16) and the wall (12) are adapted to apply a negative pressure toward a portion of the hollow organ, and the wall (12) forms a fluid-tight barrier separating the internal fluid passage (14) from the porous layer (16), and at least opposing longitudinal end faces (18) of the porous layer (16) are covered by fluid-tight covers (20) connected to the respective longitudinal ends of the wall (12).

Description

Detailed Description of the Invention

[0001] [Technical Field] The present invention relates to a stent for introduction into a hollow organ of a human or animal patient, particularly into the gastrointestinal tract, which may be particularly suitable for providing vacuum sealing of leaks in specific anatomical regions within the hollow organ, for example for the treatment of localized anastomotic failure.

[0002] [Background technology] Leaks in surgical sutures (anastomoses) in the gastrointestinal tract pose a significant health risk and therefore constitute one of the most serious complications after surgery in the abdominal region. When a leak occurs, stomach or intestinal contents enter the abdominal cavity, thus resulting in peritonitis, which is still fatal in approximately 20% of cases today. Treating a leak depends on the location and the pathophysiological characteristics of the leaked intestinal contents at the time of leakage. Healing of the sutures can be delayed, and the functional results of the surgery, such as continence, can be impaired. Often, to save the patient's life, fairly invasive procedures are required, such as surgical intervention involving removal of the intestinal continuity and creation of a colostomy. The process of creating a colostomy is feasible only in a small percentage of affected patients.

[0003] For example, attempts to seal anastomotic defects using endoscopically placed intraluminal covered stents or other conventional stents have often been found to be unsuccessful in properly sealing sutures in hollow organs. This finding is generally attributed to a mismatch between the applied stent and the irregularly shaped bowel wall. Self-expanding stents with high resilience cannot be used to completely seal the area of ​​leaking sutures. They may instead induce further damage to the suture site and even cause suture site rupture.

[0004] Even if complete sealing of the defect is ultimately achieved in exceptional cases, it is found that contents from, for example, hollow organs, such as intestinal contents, that have entered the area of ​​the suture cannot be evacuated. The formation of abscesses at suture sites almost inevitably occurs, particularly in the gastrointestinal tract, thereby resulting in local pathological conditions and further deterioration of the patient's medical condition.

[0005] To improve the sealing effect provided by stents on the wall of hollow organs, such as the intestine, the implementation of porous foam has been proposed. The porous foam can be placed on the outside of the stent body and held in place by the radially outward pressure exerted by the stent body. Furthermore, evacuation of harmful contents from the corresponding hollow organ can be applied. A cannula can be envisioned on the outside of the stent body, for example, within the porous material. By applying a pressure lower than atmospheric pressure, the sealing of the sutures can be envisioned. With such an approach, surgeons may even avoid necessarily suturing the lesion.

[0006] However, it has been found that the use of stents usually means the occurrence of local tissue ingrowth. In particular, porous materials and typically mesh-like stent bodies appear to be susceptible to tissue ingrowth. The use of mesh-like stent bodies can also require significant manufacturing efforts. In particular, the positioning and fixation of stent components relative to one another can require complex manufacturing efforts to ensure that their relative positions are maintained during deployment and / or application of the drainage function. Furthermore, ensuring that mesh-like stent bodies are liquid-tight can be challenging in stent design and manufacturing.

[0007] Therefore, there is a need to facilitate the manufacture of stents and to further improve their properties in terms of patient safety and therapeutic efficacy.

[0008] Summary of the Invention Therefore, starting from the known prior art, it is an object of the present invention to provide a stent that effectively seals a localized defect, such as a leaking surgical suture. Advantageously, the stent structure can effectively prevent leakage toward or from the treated anatomical structure by providing a reliable and intimate connection with the hollow organ body site being sealed and / or treated. Preferably, such a stent also allows for the effective removal of fluids accumulated at the defect site of the human or animal hollow organ. Furthermore, such a stent is preferably manufactured by a less expensive and sophisticated manufacturing process.

[0009] This object is achieved by the stent of the invention according to the independent claims. Preferred embodiments are shown by the dependent claims, the description and the drawings.

[0010] Thus, a stent for introduction into a hollow organ of a human or animal body, preferably the gastrointestinal tract, particularly the intestine, is disclosed. The stent of the present invention comprises a stent body, preferably radially elastic, having a wall defining an internal fluid passageway from one end of the stent body to the opposite longitudinal end of the stent body. The stent further comprises a porous elastic layer. Both the porous layer and the wall are adapted to apply a negative pressure to the hollow organ implantation site. The porous layer covers the outer surface of the wall along its entire circumference and along a predetermined longitudinal cross section of the stent body. According to the present invention, the wall or the stent body forms a liquid-tight barrier separating the internal fluid passageway from the porous layer. According to the present invention, the stent wall itself is liquid-tight. It is not necessary to cover the stent body, e.g., a mesh-like stent body, with a liquid-tight layer. At least the opposite longitudinal end faces of the porous layer are covered by liquid-tight covering materials connected to the respective longitudinal ends of the wall.

[0011] By providing a continuous wall structure that is liquid-tight, the sealing function against the fluid passage and the outside is ensured, especially during deployment. The stent of the present invention does not require the application of additional coatings, embedded structures, or foil materials to ensure sealing. Due to the sealing function provided by the wall (or the stent body) of the stent of the present invention, such additional components can be effectively omitted. As a result, the manufacturing of the stent of the present invention is significantly easier. Furthermore, potential discontinuities in sealing can be effectively avoided.

[0012] The fluid-tight wall structure also reduces undesirable ingrowth of surrounding local tissue into the fluid passageway. The fluid-tight configuration of the wall has the additional advantage that bodily fluids passing through the stent passageway are not transported or diffused toward the surrounding tissue at the implantation site, e.g., at suture or leak sites, and do not invade surrounding organs or enter the blood circulation. In particular, the presence of anastomoses in the surrounding tissue does not indicate, or at least reduces, the risk of sepsis when using the stent of the present invention. Providing the fluid-tight wall structure allows the stent to be removed without causing tissue damage, or at least without exacerbating such tissue damage. Finally, the stent of the present invention promotes wound healing of the surrounding tissue.

[0013] The wall structure of the body improves the mechanical stability of the stent. In particular, the wall structure can be configured to have a greater radial elasticity than a longitudinal elasticity. Alternatively, the elasticity of the stent can be essentially limited to the radial direction. The stent body is preferably essentially cylindrical or tubular. However, at least one cross section of the stent body may have other cross-sectional shapes, such as an ellipsoidal shape. A cylindrical or tubular shape may further improve the mechanical stability of the body and the stent as a whole. The body is preferably an elongate body having an essentially continuous longitudinal extension. The body may exhibit one or more curvatures. These curvatures may establish the shape of the stent to correspond to the particular hollow organ structure to be supported or sealed, such as the sigmoid colon.

[0014] The radial elasticity of the wall facilitates compression of the stent for deployment into the target tissue, i.e., for collapsing the stent for delivery to the target lesion or suture via an appropriate delivery system and catheter. In other words, in contrast to known non-compressible stent bodies, the radial elasticity may allow for significant compression to reduce the size or diameter of the stent to facilitate insertion into a hollow organ and deployment into the target tissue. The elasticity or radial flexibility hierarchy further supports the adaptability of the stent to the respective anatomical structure of the site where the stent is applied, such as the intestinal wall or the wall of a specific region of the intestine. Depending on the size of the stent body, the elasticity of the stent may be held in place, for example, by applying a radial force. The stent body may be configured to be self-expanding, for example, made of a self-expandable plastic material.

[0015] The luminal diameter of the stent according to the invention, i.e. the inner diameter of the wall of the stent body, is preferably in the range of about 10 to 50 mm, preferably 15 to 35 mm, in particular 15 to 30 mm, and most particularly preferably about 20 to 30 mm, such as 23 to 26 mm (for example for application in the colonic region) or about 10 to 20 mm, such as 10 to 15 mm (for example for use in the esophagus). In each case, the diameter of the stent is selected depending on the area of ​​application so as not to impede the passage of the corresponding substances through the respective hollow organ (for example the passage of stool or feces in the case of the intestinal tract).

[0016] The fluid passageway of the stent body, or the stent body at its site of deployment (as similarly referred to throughout this invention), may be understood as a through passageway or internal cavity having opposing openings. The stent body thus forms a hollow body having a lumen. The stent body is longitudinally open, allowing fluid (e.g., viscous or semi-viscous) to enter the passageway through one end and exit the passageway through the opposite end.

[0017] Preferably, the wall of the stent body is liquid-tight and / or gas-tight, preferably liquid-tight and gas-tight. The stent may be equipped with a drainage means such as a cannula. The drainage means may be located on the outside of the wall. A negative pressure, i.e., a pressure below atmospheric pressure or a vacuum, may be applied to the space between the wall of the stent and the inner wall of the hollow organ. Any contents leaking into this intermediate space (between the outer wall of the stent and the inner wall of the hollow organ) can be effectively evacuated by the negative pressure or suction pressure. A (suitable) vacuum may further facilitate sealing of the lesion or suture, thereby promoting the healing process. In particular, the wall of the stent may be configured to withstand a negative pressure of -60 mmHg to -200 mmHg, preferably -80 mmHg to -125 mmHg. Therefore, the stent according to the present invention is preferably configured as a suction stent.

[0018] The elastic porous layer is preferably moldable and / or compressible. In the absence of compressive force, the porous layer typically returns to its original, uncompressed state. The porous layer may surround the stent body, e.g., be tubular with a central through-hole that accommodates the stent body. The porous layer may be formed of a closed-pore material, typically in the form of a foam, or an open-pore material, i.e., in the form of a sponge. Preferred porous layer materials are, for example, plastic foams containing or consisting of silicone, polyurethane, polyvinyl alcohol, or mixtures of such plastic materials.

[0019] The porous layer preferably has a thickness of about 5 mm to about 20 mm, preferably about 5 mm to about 12 mm or about 5 mm to about 10 mm, depending on the anatomical dimensions and structural constraints encountered at the application site, such as the required elasticity or structural constraints for filling the space or volume between the stent body and the inner wall of the hollow organ.

[0020] The stent body and / or stent according to the present invention is preferably fully elastic, compressible, and optionally expandable as a whole. In particular, the stent body or stent as a whole is not incompressible, such that it can be compressed, for example, when introduced into a catheter and delivered by the catheter. The fully elastic nature of the stent allows it to be positioned at the application site. The stent according to the present invention, particularly a fully elastic stent, can be delivered to the application site in the gastrointestinal tract, preferably the esophagus, intestine, primarily the rectum, sigmoid colon, descending colon, or transverse colon, by conventional application means.

[0021] The extension of the porous layer preferably corresponds to the longitudinal extension of the body. Such an embodiment results in the entire outer wall being covered with the porous layer. This allows for optimizing the sealing function relative to the surface area of ​​the target tissue to be treated. The loading, fixation, and / or proper positioning of the stent may be improved. However, for other embodiments, the wall of the stent body may be provided with extensions at one or both of its longitudinal ends. As a result, the wall of the stent body may be only partially covered with the porous layer.

[0022] The wall and / or porous layer of the stent body are preferably made of a plastic or rubber material. Preferably, both the wall and the porous layer of the stent body are made of a plastic or rubber material. The provision of a plastic or rubber material can promote the elasticity of the entire stent. These materials can also allow the wall to form a liquid-tight barrier. The plastic or rubber material also contributes to improving the adaptability or conformity of the wall of the stent body to the inner wall of the hollow organ, improving the sealing and fixation of the stent in place.

[0023] The materials of the stent body and porous layer are preferably (fully) biocompatible, so that the deployment and presence of the stent in the target tissue, i.e., hollow organ, does not cause any factor, or at least does not cause any significant foreign body reaction.

[0024] The porous layer may be formed of or comprise one or more plastic material foams, for example comprising or consisting of silicone, polyurethane, polyvinyl alcohol, or mixtures of these plastic materials. The wall of the stent body may be formed of or comprise a plastic or polymeric material, for example selected from the group comprising polyurethane and latex.

[0025] Preferably, the wall and / or porous layer of the stent body is made of a silicone-based material, preferably a material containing or consisting of silicone. Silicone-based materials are particularly advantageous in that they are easy to handle during manufacturing. For example, materials such as PDMS or silicone can be easily formed using a mold and cured within a predetermined curing time. Silicone-based materials also exhibit excellent biocompatibility. A material exhibiting the required elasticity value can be selected from many silicone-based materials.

[0026] In one embodiment of the present invention, the wall of the stent body is silicone-based and the porous layer can be formed of another, different material, such as one or more polyurethane foam materials, i.e., the wall of the stent body and the porous layer can be formed of different materials or material compositions.

[0027] In a preferred embodiment, the wall of the stent body and the porous layer are formed of the same material. In particular, the porous layer may be formed of a foamed material having a density lower than that characterizing the wall of the stent body. Using only a single material or material composition to form the stent body and the porous layer may facilitate the manufacture of the stent. For example, foaming the porous layer material using air or other (gas) fluids reduces the density of the porous layer material. This may improve the compressibility and adaptability to the inner wall of a hollow organ. As a result, the positioning and maintenance of the correct position after deployment of the stent may be improved. The wall of the stent body is preferably not based on a foamed material. This ensures the necessary mechanical robustness, exhibiting elasticity, and a liquid-tight structure of the stent body (wall). Therefore, the wall of the stent body preferably exhibits a density greater than that of the foamed porous layer.

[0028] The porous layer may have an essentially uniform density, or alternatively may have a density gradient, for example increasing from the inner periphery to the outer periphery of the porous layer.

[0029] To further facilitate the manufacture of the stent, the wall of the stent body and the porous layer can preferably be manufactured as a single unit. The wall of the stent body and the porous layer can be fixed to each other in a material bonded manner, for example, by adhesive. The wall of the stent body and the porous layer can be formed of different materials or material compositions, but the final curing step or time can preferably still be carried out simultaneously, i.e., with the porous layer covering the periphery of the wall and in contact with it. Thus, the wall of the stent body and the porous layer can preferably form an integrated part by material bonding.

[0030] A single structure, such as an integral portion of the stent body wall and porous layer, preferably by material bonding, has the advantage that the structural integrity of the stent is significantly improved and the material properties are essentially uniform along the longitudinal extension of the stent. Furthermore, a single structure essentially does not require mechanical fixation to ensure that the porous layer maintains a fixed position relative to the body wall. This ensures that the stent is fully functional. In particular, it ensures that no part of the stent, such as part of the porous layer, remains in the patient's body when the stent is removed.

[0031] The extension of the stent body along a given cross section is preferably configured so that the longitudinal end faces of the porous layer are covered with a liquid-tight cover. This cover can typically be represented by a sheet-like layer. The liquid-tight cover can also be connected to each longitudinal end of the wall or the stent body. This fixes the porous layer mechanically, preferably conformally, to the stent body.

[0032] In the deployed state, the longitudinal direction of the porous layer typically extends at least partially parallel to the inner wall of the hollow organ at the target application site, i.e., a predetermined anatomical region of the hollow organ exhibiting a leak, wound, or lesion. However, providing covers on each end face may offer additional advantages. The porous layer can contact the target tissue in the longitudinal direction, i.e., at the inner wall of the hollow organ facing the (distal) end face of the porous layer. This can ensure improved sealing toward the surrounding tissue or lumen of the organ, e.g., a portion of the intestinal tract. In particular, covers on the longitudinal ends of the porous layer and the stent body can prevent leakage of bodily fluids. In other words, they can prevent, for example, bodily fluids, stool, or feces from penetrating the porous layer or the interface or region between the porous layer and the inner wall of the hollow organ through either of the respective ends. Such an embodiment according to the present invention is advantageous for proper tissue healing.

[0033] Preferably, the cover is made of a soft and / or flexible material, such as a deformable plastic or rubber material. Thus, the physical properties of the cover can be selected to reduce the risk of damaging the surrounding tissue. Preferably, the cover is adaptable to the anatomy of the surrounding tissue. This provides an improved sealing function as well as a level of cushioning or support for the surrounding tissue.

[0034] To further improve the sealing against the surrounding tissue, the outer periphery of the porous layer is preferably covered by a cover at the longitudinal ends of the porous layer. Thus, the cover extends from each end of the wall of the stent body, through each longitudinal end face of the porous layer, to and over the outer periphery of each end of the porous layer. In other words, the cover can form a sandwich structure and cover the entire outer end of the porous layer that is not covered by the wall of the stent body. This further reduces the risk of unwanted leakage of, for example, bodily fluids or feces, into the target tissue.

[0035] Improved mechanical fixation of the porous layer to the wall of the stent body is achieved by providing an increased contact surface, and the conformality of the porous layer between the covers at each longitudinal end is improved, thereby maintaining the structural integrity of the stent during deployment into the target tissue and removal.

[0036] As mentioned above, the covers at each end face can advantageously reduce the risk of, for example, bodily fluids leaking to and from the target application site, e.g., an anastomosis. Because the covers are connected to the wall of the stent body, they can provide additional mechanical fixation to the wall of the porous layer, e.g., in a form-fitting manner. This establishes mechanical fixation at least in the longitudinal direction. However, as mentioned above, mechanical fixation can also be provided in the radial direction by covering the outer periphery of the porous layer at each end.

[0037] In one embodiment, the covering can extend as a sheet-like covering from each longitudinal end of the wall. During manufacturing of the stent (or during preparation of the stent for deployment), the covering can extend, for example, beyond the end face of the wall, tapering radially outward (e.g., from the wall), and then be folded back and positioned around the porous layer at each end. The covering extends from the wall, beyond the end face of the porous layer, and beyond the outer periphery of the end of the porous layer. In other words, the sheet-like covering can be folded backward, i.e., along the outer surface of the stent, toward the other longitudinally opposing end of the stent. Thus, the covering not only covers the end face and optionally the outer periphery, but also facilitates fixing of the porous layer to the wall of the stent body.

[0038] Depending on the dimensions and material of the cover, a gradual conformance of the porous layer may be achieved, for example, so that radial or longitudinal forces acting on the porous layer result in a corresponding displacement. However, the fixation of the porous layer to the wall by the cover at its longitudinally opposed end surfaces ensures that the porous layer is biased between the opposed end regions, at least during stent deployment, thereby ensuring proper implantation of the stent at the target site.

[0039] Preferably, the cover and the stent body wall are integrally formed. For example, both the cover and the stent body wall can be formed from a silicone-based material, and the stent body wall and the cover can be cured simultaneously in a single mold. This significantly improves the mechanical fixation of the cover to the stent body wall, eliminating the need for a separate fixation step or attachment means. This contrasts with prior art solutions that implemented separate sealing elements that needed to be fixed to a portion of the stent or stent body. Such prior art solutions were not only cumbersome, but also typically resulted in sealing defects due to insufficient or loose sealing elements. Instead of a silicone-based material, the cover could also be formed from polyurethane, latex, hydrocolloid, lyogel, or hydrogel. The cover preferably provides a homogeneous, structurally robust seal. The cover can establish a liquid-tight, i.e., air-tight and water-tight, seal.

[0040] To improve the foldability of the sheet-like covering, the covering is preferably thinner than the wall of the stent body. This allows the covering, which typically exhibits reduced elasticity, to have more flexible properties. This advantageously allows it to cover the respective end faces of the porous layer and potentially predetermined shapes, such as curved portions. The thinner sheet-like material can be formed as a foil or membrane, for example, depending on the on-site constraints at the target site.

[0041] In another embodiment, the cover is bonded to the wall of the stent body and the porous layer in a material-bonded manner. The cover can be, for example, silicone-based. The cover material can be applied by dipping at least the end surface of the porous layer and the adjacent wall of the stent body. Thus, for example, a liquid cover material can be uniformly applied to the wall and / or end surface of the porous layer by a dipping process. After the cover material hardens, it can engage with or fill the pores of the porous layer. This can significantly improve the mechanical fixation of the porous layer to the body wall. Furthermore, applying the cover material and fixing the porous layer essentially requires only a single dipping process for each respective end portion, which can further facilitate manufacturing.

[0042] Opposite longitudinal ends of the porous layer may have enlarged radially outward extensions. In other words, the ends of the porous layer may have a greater radially outward extension than the portion of the porous layer between the ends, e.g., the portion (other than the ends) exhibiting an essentially cylindrical or tubular shape. Thus, the opposite ends may have a varying cross-sectional area or shape and / or exhibit a radial increase in thickness, e.g., compared to a portion of the porous layer having an essentially continuous cross-sectional area.

[0043] Preferably, the ends of the porous layer exhibit a mushroom, dome, toroidal, or donut shape. The porous layer preferably has a barbell shape in its longitudinal cross section. The preferred shape exposes a rounded surface without sharp edges, thereby reducing the risk of tissue damage at the contact points with the epithelium of the hollow organ, especially during deployment or dislodging of the stent body. The rounded shape also ensures improved conformity and sealing to the local anatomical structure of the application site, i.e., conformity to the inner wall of the hollow organ. Alternatively, one or both of the longitudinally opposing ends of the stent body or its wall may also exhibit one of the above-mentioned shapes, for example, one of the longitudinally opposing ends may be formed as a radially extending toroidal shape. The other longitudinally opposing end may, for example, have a similar shape, a radial flange-like extension, or no radial extension.

[0044] In this regard, the enlarged radial extension of the opposing ends also allows the stent to be positioned such that, for example, a lesion or suture in a hollow organ contacts the cross section of the stent between the respective end regions, thereby isolating the lesion or suture from the lumen of the hollow organ. Targeted application of vacuum or evacuation to the site of the lesion or suture may also be supported.

[0045] Preferably, at least one longitudinal end of the porous layer and each cover are configured to accommodate a cannula. In particular, the proximal end of the stent may be advantageously configured to accommodate a cannula. In this regard, the cover ensures that the cannula's entrance is properly sealed. Such sealing is preferably achieved by applying a semi-cured or uncured covering material to at least each end surface of the porous layer and around the cannula at the entrance site into the porous layer. Alternatively, for example, the cover may be characterized by a predetermined hole sized to accommodate the cannula in a press-fit manner, and / or may be provided with an additional sealing agent, such as a silicone-based material including a hydrogel.

[0046] Therefore, the stent preferably further comprises a cannula housed by the porous layer on the exterior of the wall. For example, the stent may comprise a cannula or other drainage means housed alongside the stent body. The stent may be guided through the porous layer or along the interface established by the porous layer and the wall of the stent body, for example, at each longitudinal end of the stent. Thus, the cannula may preferably be disposed in the space between the porous layer and the outer periphery of the wall of the stent body. The cannula may, for example, be engageable with a vacuum or negative pressure source, and, in an implanted and deployed state, may provide a vacuum or negative pressure within the space defined by the wall of the stent body and the inner wall of the hollow organ. As described above, applying a negative pressure or vacuum, i.e., a pressure or vacuum below atmospheric pressure, may promote wound healing by providing or promoting closure of a lesion or wound adjacent to or covered by the porous layer and / or by ensuring the evacuation of wound fluid or potentially contaminated or semi-contaminated liquids, such as stool or feces.

[0047] Preferably, the cannula is positioned so that its distal opening is adjacent to the distal end of the porous layer, e.g., within a section that occupies 60% to 85% of the total length L of the stent. This can improve the effectiveness of applying negative pressure, e.g., by an extracorporeal device, along the longitudinal extension of the stent. In particular, the distal opening of the cannula can be positioned within or immediately proximal to the radially extending distal end of the porous layer. In one embodiment, the cannula does not have only a distal opening. The cannula may further comprise one or more openings or holes in its wall that are located closer to the distal end of the cannula. Such additional openings or holes in the side wall of the cannula can also be located at a corresponding proximal end of the porous layer, e.g., at the radially extending proximal end of the porous layer. Depending on the required level of (negative) pressure distribution and / or drainage, one or more openings or holes can be foreseen in the side wall of the cannula between the proximal portion of the cannula at the proximal end of the porous layer and the distal opening of the cannula. Thus, various numbers of such additional openings or holes, for example 2 to 6, can be foreseen in the side wall of the cannula along the extension of the porous layer.Advantageously, the cannula is arranged as a component of the stent so that the openings in the side wall of the cannula are directed radially outward.

[0048] The stent may also comprise a plurality of cannulas housed within the space defined by the porous layer and / or by the wall of the stent body and the porous layer, the distal ends of which have distal openings being advantageously arranged to be located at different sites along the longitudinal extension of the stent, such that the location of the respective distal openings of each cannula is different, for example, for applying uniform (negative) pressure conditions along the extension of the stent at the implantation site, or for applying negative pressure gradients, or for applying peak negative pressure conditions at the longitudinal ends, with the cannulas located adjacent to (i) the proximal longitudinal end of the stent and (ii) the distal longitudinal end of the stent.

[0049] Furthermore, other functions can optionally, preferably additionally, be performed using cannulas, such as by allowing rinsing or cleaning of the application site, e.g., with saline or other biologically compatible fluid, or by applying a liquid or gel-like tissue sealant to promote healing of a lesion or leaking suture. The rinsing or cleaning function can be provided by a cannula configured to apply negative pressure. Alternatively, to enable such rinsing or cleaning functions, one or more additional cannulas can be envisioned in addition to the cannula configured to apply negative pressure, e.g., by securing it / them to the stent body as described above. In such embodiments, the stent comprises at least one cannula for applying negative pressure and at least one additional cannula for enabling the rinsing or cleaning function.

[0050] The one or more cannulas for applying negative pressure, and optionally one or more additional cannulas for rinsing / cleaning, can be secured to the stent body by a cover at each end face, i.e., insertion face, of the porous layer. Alternatively, or in addition, the cannulas may be secured to or attached to the stent body by one or more sutures, by application of adhesive to each end face, and / or by an interference fit provided by the porous layer.

[0051] As described above, applying a vacuum can effectively evacuate contents leaked into the space between the wall of the stent body and the inner wall of the hollow organ by negative pressure or suction pressure. For example, inflammatory secretions can be evacuated from the lesion. Furthermore, by effectively removing or suctioning bodily fluids that have entered the intermediate space from the lesion, improper wound healing and sepsis associated with, for example, leakage of stool or feces can be avoided. Suction by applying such a (small) vacuum can result in or promote sealing of the lesion or wound, for example, at the wound and / or mucosal interface, which can further accelerate the healing process.

[0052] To provide selective reinforcement for the stent, the stent may include a mesh-like frame portion that surrounds or encloses only a portion of the stent body. The frame portion is preferably positioned to surround or contact only one of the opposing longitudinal ends of the stent body. Thus, at least the other longitudinal end of the stent body is not covered or contained by the frame portion. Alternatively, the mesh-like frame portion may extend along the entire length of the stent body. The mesh-like portion is preferably sandwiched between the stent body or the wall of the stent body as an inner component and the porous layer as an outer component.

[0053] In accordance with the present invention, such a configuration has been found to be particularly advantageous for rectal applications, since it has been determined that sealing failure typically increases in the direction toward the rectum and sphincter. In this regard, the frame portion has been found to advantageously provide increased sealing pressure applied toward the corresponding surrounding target tissue and / or reduce unintended deformation of the stent, e.g., the porous layer. Unintended deformation may occur, in particular, upon movement and / or (strong) contraction of surrounding muscle tissue.

[0054] On the other hand, the portion of the stent body that is not surrounded by the frame portion, thus defining a free portion, may advantageously be deployed closer to the sphincter muscle or extend towards the outside of the anus. This lack of reinforcement may make the corresponding portion of the stent body less noticeable, ensuring that the patient perceives it as comfortable and discreet.

[0055] The frame portion is preferably disposed between the porous layer and the wall of the stent body. The frame portion may be secured to the porous layer and the stent body by a material bond, such as an applied medical adhesive. Alternatively, or in addition, the frame portion may be secured or held in place by one or more material bond points between the porous layer and the wall of the stent body, which extend through the mesh wires of the frame portion and provide a positive interlock, preferably at least in the longitudinal direction.

[0056] The longitudinal portion of the stent body or its wall covered by the frame portion can be between 5% and 70% of the stent body length, e.g., between 30 and 50 mm when the total length of the stent body is between 250 and 400 mm. Preferably, the portion of the stent body surrounded or covered by the frame portion is between 40 and 60% of the stent body length, particularly between 30 and 50 mm when the total length of the stent body is between 80 and 120 mm. As mentioned above, the frame portion surrounds a portion of the stent body such that the frame portion extends along the entire circumference of the stent body. In other words, the covered portion of the stent body is therefore understood to correspond to the length of the stent body that is covered by a continuous extension of the frame portion, compared to the length of the portion of the stent body that is not surrounded by the frame portion.

[0057] Preferably, the frame portion surrounds one of the opposing longitudinal ends of the stent body so that said longitudinal end of the stent body is received within the frame portion. The frame portion preferably has a shape that matches the shape of the portion of the stent body that is received within it. Such a configuration ensures that the overall dimensions can be reduced and improves sealing and fixation of the stent body to the frame portion. Furthermore, particularly when the frame portion is disposed between the porous layer and the stent body, it allows the longitudinal end face of the porous layer to directly contact the cover extending from the stent body. Therefore, preferably, the frame portion is shaped so that the porous layer contacts the longitudinal end of the stent body that is received within the frame portion.

[0058] The longitudinal ends of the stent body that are not surrounded or covered by the frame portion, as well as the corresponding ends of the porous layer, may be configured as described above. Alternatively, the corresponding longitudinal end faces of the porous layer may be provided without a liquid-tight cover. Such a configuration may be provided, for example, when the portion of the stent body that is not surrounded by the frame portion is configured to extend toward the outside of the patient's body, for example, through the patient's anus. In such a configuration, the radial extension of the longitudinal end of the stent body may correspond to the adjacent portion of the stent body.

[0059] Alternatively, the longitudinal ends of the stent body that are not surrounded by the frame portion may extend radially as described above, and preferably may have flange-like extensions. Such a shape is particularly advantageous for providing abutments in the sphincter. To this end, the flange-like extensions may have a diameter that is, for example, 10% to 50% larger than the diameter of the adjacent portions of the stent body. In particular, for a stent body diameter of 20 mm to 28 mm, the diameter of the flange-like extensions may be 4 mm to 12 mm larger. In a particularly preferred embodiment, the diameter of the stent body may be 22 mm to 26 mm, and the diameter of the flange-like extensions may be 30 mm to 34 mm.

[0060] To facilitate stent deployment, the frame portion is preferably formed of a resilient, self-expanding material. In particular, the frame portion is based on or constructed of nitinol or other shape-memory materials. The resilience allows the frame portion to collapse for ease of insertion for stent deployment, while the self-expanding properties facilitate deployment at the target site.

[0061] In accordance with the present invention, a method for manufacturing a stent suitable for introduction into a hollow organ of the human or animal body, preferably into the gastrointestinal tract, particularly into the intestine, is disclosed, the method comprising the steps of providing a radially fluid-tight barrier-defining wall of a stent body, preferably radially flexible, and defining an internal fluid passageway from one end of the body to an opposite longitudinal end of said stent body; providing a resilient porous layer; covering the outer surface of the wall along the entire circumference of the wall and, together with the porous layer, along a predetermined cross section in the longitudinal direction of the stent body; and covering at least the longitudinally opposing end faces of the porous layer with a liquid-tight cover material contacted to each longitudinal end of the wall, the porous layer and the wall being adapted to apply a negative pressure to a portion of the hollow organ.

[0062] The wall of the stent body is preferably made of a plastic or rubber material, preferably a silicone-based material. For example, the wall of the stent body can be formed by molding and curing a material to obtain a tubular or cylindrical structure that defines a liquid-tight barrier toward the internal fluid passage. By forming the wall of the stent body according to the above-mentioned manufacturing method, a liquid-tight barrier is obtained that separates the internal fluid passage from the porous layer. The elastic porous layer can be provided, for example, as a foam structure, which can facilitate conformity to the inner wall of the target hollow organ and improve fixation of the stent at the target site.

[0063] Preferably, the porous layer and the wall of the stent body are made of the same material, and the porous layer is provided by foaming the material to obtain a layer with a lower density than the material forming the wall of the stent body, which allows the wall of the stent body to exhibit a greater density, ensuring the stent body's desired elasticity and liquid-tight barrier properties. Using the same material makes the stent easier to manufacture and provides more defined mechanical properties.

[0064] In particular, the wall of the stent body and the porous layer may be integrally formed and / or may be connected to each other by a material bond. Preferably, the porous layer and the wall are formed as an integral part, and the porous layer is formed around the periphery of the wall by foaming a porous layer material that substantially surrounds the wall of the stent body. In other words, this material can be provided with a predetermined density relative to the wall of the stent body. This density can be reduced, for example, by foaming the material with air, thereby forming a porous layer with a lower density on the outside of the wall. Thus, there is a (small) gradient, for example, from a higher density in the wall of the stent body to a lower density in the radially outer area of ​​the porous layer. The porosity of the porous layer can be adjusted by appropriate selection of material and / or foaming amount, for example, air velocity, duration, screw-in depth, etc.

[0065] In one embodiment, the cover can be formed as a sheet-like longitudinal extension of the wall, folded around each longitudinal end of the porous layer so as to cover at least each end face of the porous layer. The cover can be formed, for example, as a longitudinal and / or radially outward extension of the wall, and preferably exhibits a reduced thickness compared to the wall. The reduced thickness facilitates application of the sheet-like cover material onto the porous layer, particularly covering the outer periphery of the porous layer at each longitudinal end. The sheet-like material can be applied to the porous layer, for example, in a semi-cured state. The sheet-like material is then fully cured to cover the porous layer. Alternatively, if necessary, the sheet-like material can be (further) attached to the porous layer by other means, preferably by corona plasma treatment or application of a sealant.

[0066] In a further embodiment, the covering is established by immersing each end face of the porous layer and each longitudinal end of the wall in a (liquid or semi-liquid) covering material. As described above, the (semi-liquid) covering material is uniformly applied by immersion. After the covering material hardens, it closes the pores of the porous layer. Thus, the mechanical fixation of the porous layer to the wall of the stent body can be ensured or improved essentially in a single step.

[0067] Preferably, the cannula is disposed in the space between the wall of the stent body and the porous layer and / or inserted into the porous layer. When the cannula is inserted into the porous layer, it typically does not directly contact the stent body. For example, the cannula can be inserted from the longitudinal end face of the porous layer, particularly the proximal end. Then, each end face of the porous layer and each longitudinal end face of the wall can be immersed in a cover material. When the cannula is disposed in the space between the wall of the stent body and the porous layer, it is first fastened or fixed to the wall of the stent body. Then, the porous layer can be placed on the stent body with the cannula fixed. Finally, each end face of the porous layer and each longitudinal end face of the wall can be immersed in a cover material.

[0068] The cannula is preferably fixed to the stent body by one or more sutures, for example by application of adhesive at each end face of the porous layer that houses the cannula, and / or by an interference fit provided by the porous layer, and / or by the cover at each end face of the porous layer that houses the cannula.

[0069] The above-described method can further include the step of providing a mesh frame portion. Optionally, the mesh frame portion is arranged so that only a portion of the stent body is surrounded by the mesh frame portion. Advantageously, prior to the step of covering the outer surface of the wall with a porous layer, the mesh frame portion is arranged around the stent body, with the mesh frame portion being at least partially disposed between the porous layer and the wall of the stent body.

[0070] The features and advantages mentioned with respect to the stent also apply to the manufacturing method, and vice versa. According to another aspect, there is provided a method for sealing a leak, lesion or wound in a hollow organ of the human or animal body, preferably the gastrointestinal tract, especially the intestine, said method comprising: (a) introducing a stent according to the present invention into a hollow organ, thereby allowing said stent to cover a leak or lesion; (b) applying subnormal pressure to the target implantation site of the stent through the cannula to adsorb the hollow organ to the porous layer at the target implantation site.

[0071] A stent configured as a suction stent can be introduced into a hollow organ in a compressed state and advantageously deployed at the target implantation site in the hollow organ using a catheter and / or endoscope. Therefore, the method applies to a stent equipped with a cannula, as disclosed herein. Subnormal pressure applied outside the body is transmitted to the stent implantation site via the cannula. The inner wall of the hollow organ is adsorbed by a porous layer. This prevents bodily fluids passing through the hollow organ, such as stool and feces, from contacting a lesion or wound at the implantation site in the hollow organ. This promotes wound healing and significantly reduces the risk of infection caused by bodily fluids, such as sepsis. By equipping the stent with, for example, a separate cannula, the method may include a further step of rinsing or washing the implantation site in the area of ​​the lesion or leak, for example, with an isotonic solution.

[0072] BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which: FIG. 1 shows a schematic view of a stent according to the invention in longitudinal section; FIG. 2 shows a schematic view of a stent according to the invention in longitudinal section, according to another embodiment; FIG. 3 shows a schematic diagram of a method for manufacturing a stent according to the present invention; FIG. 4 shows a schematic view of a stent according to the invention in longitudinal section according to another embodiment with a frame portion; FIG. 5 shows a schematic view of a stent according to the invention in longitudinal cross section according to another embodiment having a frame portion. The illustrated embodiments do not limit the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0073] The present invention will now be described in more detail with reference to the accompanying drawings, in which like elements are designated by like reference numerals and repeated description may be omitted to avoid redundancy.

[0074] In Figure 1, a schematic diagram of a stent 10 according to the present invention is shown in longitudinal cross section. Stent 10 is radially compressible and has a predetermined elasticity so that it can be folded for deployment by conventional application means. Stent 10 returns to its original state at the deployed site and can exert a (small) radial force against the inner wall of the hollow organ at the target site. Stent 10 may optionally be (self-)expandable. Stent 10 may have various dimensions to fit the dimensions of the hollow organ, particularly the gastrointestinal tract, preferably the esophagus, intestine, mainly the rectum, sigmoid colon, descending colon, or transverse colon.

[0075] Stent 10 essentially comprises a stent body formed by a wall 12. According to this non-limiting embodiment, the stent body is formed from a plastic or rubber material, preferably a silicone-based material. Thus, wall 12 is advantageously formed from a resilient, compressible, and foldable material.

[0076] The stent body wall 12 has an essentially tubular shape and an essentially continuous cross-sectional area. The stent body wall 12 extends longitudinally, for example, from the proximal end to the distal end. The term "proximal" should be understood to refer to the insertion site, and the term "distal" should be understood to refer to the application site, toward which the interventional stent 10 is delivered.

[0077] Between its longitudinal ends (26A, B), the wall 12 defines a continuous fluid passageway 14. The wall 12 is formed as a continuous, essentially homogeneous, liquid-tight barrier, preferably formed of a single plastic or rubber material, such that the passageway 14 is radially sealed by the wall 12. The wall 12 thus ensures that bodily fluids, feces, or stool are not transported through or through the wall to the exterior of the stent 10, thereby preventing the stent from being transported through or through the wall to the exterior of the stent 10 in its deployed state (i.e., lesions or leaking sutures are significantly reduced. Potential medical complications resulting from the passage of such materials can be effectively avoided).

[0078] Sealing toward the interior wall of the hollow organ is facilitated by porous layer 16, which is indicated by corresponding hatching. Porous layer 16 surrounds wall 12 along its periphery. Porous layer 16 may be formed from a biocompatible foam or sponge material to provide sufficient formability and conformability to the local tissue and anatomical structures at the application site. Such a material may also help mechanically secure stent 10 at the desired application site. As shown, porous layer 16 includes end portions (26A, 26B) with increased radial extension, each forming a convex and / or toroidal portion. Porous layer 16 may define a barbell shape in longitudinal cross-section. The increased radial extension helps to hold the stent 10 securely in place and may also provide improved lesion sealing when the stent 10 is positioned such that the lesion is located, for example, across the gastrointestinal wall and between the respective longitudinal ends of the stent 10.

[0079] The passageway 14 and the improved seal provided by the ends (26A, 26B) of the porous layer 16 and the wall 12 of the stent body allow the physiological function of the hollow organ to be re-established while lesions or leaking sutures, e.g., anastomoses, can heal without significant disruption.

[0080] At the longitudinal end faces 18 of the porous layer 16, covers 20 are foreseen, connected to the respective longitudinal ends (26A, 26B) of the wall 12 and extending around the end faces 18 to provide radial coverage. The covers 20 are liquid-tight, ensuring that the porous layer 16 is radially sealed at the respective longitudinal ends (26A, 26B). Thus, they can provide a sealing function for the adjacent inner wall of the hollow organ facing the porous layer 16. This prevents bodily fluids, excrement or feces from entering the intermediate space between the opposing longitudinal ends (26A, 26B) on the one hand, and between the wall 12 and the inner wall of the hollow organ (radially) on the other hand.

[0081] The cover 20 according to this non-limiting example is integrally formed with the wall 12 and / or connected via a mechanical bond to improve structural integrity and simplify manufacturing. The cover 20 is formed as a sheet of material extending from the wall 12 and connected in a material-bonded manner, as indicated by the small lines at the interface between the wall 12 and the cover 20. The sheet of material has a thickness less than that of the wall 12, facilitating application of the cover 20 to the porous structure of the porous layer 16 at each end surface 18. The sheet of cover 20 can be applied to each end surface 18 in a semi-cured state, for example. Alternatively, or in addition, the sheet of cover 20 can be attached to each end surface 18 by, for example, corona plasma treatment. Corona plasma treatment has been found to provide particularly effective bonding, for example, to silicone-based materials.

[0082] Also shown in Figure 1 is a cannula 22. The cannula 22 is received at the (proximal) end region, introduced through the cover 20, and accommodated along the portion of the wall 12 between the proximal end region and the opposing distal end region. The cover 20 comprises an inlet opening (28) that is sized and adapted to receive the cannula 22 such that the cannula 22 is completely surrounded by the cover material 20, preferably in a liquid-tight manner. The cannula 22 allows a negative or suction pressure to be applied between the radially outwardly extending longitudinal ends (26A, 26B) of the porous layer 16, thereby appropriately closing off the hollow inner wall representing the lesion. As shown, the cannula 22 is preferably housed within the porous layer 16 such that its distal opening (24A) is positioned at or near the distal longitudinal end (26B) of the porous layer 16, advantageously in a region defined as 60% to 85% of the total stent length L, with the proximal end of the stent being 0%. However, the cannula can alternatively be secured to the wall of the stent body (without any porous layer material disposed between the cannula and the wall of the stent body (not shown)). In this non-limiting example, the distal opening (24A) of the cannula 22 is accordingly positioned adjacent to the distal, enlarged, radially outward extension of the porous layer 16. The porous layer 16 can facilitate proper positioning and fixation of the stent 10 relative to the inner wall of the hollow organ while ensuring that the inner wall of the hollow organ does not come into direct contact with the cannula 22. This allows the suction force applied to the inner wall of the hollow organ to be controlled and distributed more evenly: inadvertent suction of the inner wall can be effectively avoided.

[0083] At least one additional opening, e.g., two to six additional openings (24B and 24C), may be provided as holes in the wall of the cannula (22). These may be foreseen at the sidewall in contact with the porous layer (16). These openings may ensure that subnormal pressure is applied more evenly along the length of the stent, thereby ensuring that the wall of the hollow organ is adhered to the stent at the implantation site.

[0084] The embodiment of Figure 1 shows one single cannula 22. However, it is also possible to foresee multiple cannulas 22. In addition to the cannula 22, the stent according to the embodiment of Figure 1 may be equipped with at least one additional cannula 30 (not shown in Figure 1) for rinsing and cleaning.

[0085] 2, a stent 10 according to another embodiment is shown schematically. According to the exemplary embodiment, the porous layer 16 (shown hatched) does not include enlarged radially outward extensions at the opposing longitudinal ends (26A, 26B). Furthermore, the porous layer 16 may optionally extend longitudinally beyond the wall 12. This may be advantageous, for example, to support the extension of a cannula (not shown) without requiring an enlarged dimension of the wall 12. This may be particularly advantageous if the wall 12 of the stent body has greater elasticity, so that the stent 10 as a whole may better conform to the anatomical shape of the target site.

[0086] Additionally, a cover 20 extends from the wall 12 and is present at each end surface 18. As indicated by the thick semicircular arrows, the cover 20 may be folded over the porous layer 16 at each longitudinal end (26A, 26B) to cover the outer periphery of the porous layer 16. This further improves the sealing function of the cover 20 and ensures that substances transported through the stent lumen, preferably fluids such as stool or feces, do not pass through the longitudinal end surface 18 and the adjacent inner wall of the hollow organ. The folding can be performed during manufacturing, e.g., in a semi-cured state, or before the stent 10 is subsequently folded for deployment. Prior to deployment, the cover 20 may optionally be secured to the outer periphery of the porous layer 16 using, for example, corona plasma treatment, application of a sealant or adhesive, or other suitable means. The degree to which the cover 20 is secured to the outer periphery of the porous layer may depend on the specific requirements of the stent 10 for each therapeutic application and / or the overall configuration of the stent 10. For example, additional means for attaching the cover 20 to the outer periphery of the porous layer 16 may be provided during deployment of the stent 10 and / or during treatment of the target site, eg, a lesion.

[0087] FIG. 3 illustrates a schematic diagram of a series of method steps for manufacturing a stent 10 according to the present invention. Thus, in the first step shown at the top left, a stent body is provided, including a cylindrical or tubular wall 12. The wall may be formed, for example, by molding, preferably from a silicone-based material. Alternatively, the wall 12 may be formed by extrusion. However, molding may be particularly advantageous for soft plastic or rubber materials, reducing the amount of material required to form the wall 12. As shown, the wall 12 defines an internal fluid passageway 14 between its longitudinally opposed ends (26A, 26B), which is radially sealed by the wall 12 in a fluid-tight manner, as described above.

[0088] Although porous layer 16 may be provided separately or applied along the periphery of wall 12, according to this non-limiting example, porous layer 16 is formed by foaming excess wall material at its periphery, as shown by the corresponding symbol in the upper left panel. Thus, porous layer 16 is formed over, i.e., surrounding, and extending radially outward from wall 12, as shown by the corresponding hatching in the upper right panel.

[0089] After the porous layer 16 is formed, it may exhibit a density gradient and / or increased radial outward extension, for example, at opposing longitudinal ends (26A, 26B) (as shown in FIG. 1 ). The wall 12 and each longitudinal end (26A, 26B) of the porous layer 16 are immersed in a liquid material to form a cover 20, as shown in the lower right panel. This causes the cover 20 to be applied uniformly along each end surface 18, simultaneously contacting both the wall 12 and, by example, the outer periphery of the porous layer 16 at each end (26A, 26B).

[0090] The result after applying the material to form the cover material 20 via dipping and corresponding curing is depicted in the lower left panel. Thus, the wall 12, cover 20, and porous layer 16 are integrally formed and / or secured to one another by material bonding. This results in improved mechanical stability. Since essentially no additional mechanical attachment is required, manufacturing may be significantly easier. Furthermore, as shown, the interior wall of the hollow organ located between the opposing longitudinal ends (26A, 26B) can be effectively sealed toward the fluid passage 14 by the cover 20 and wall 12, so that contamination can be maximally avoided.

[0091] 4 shows a schematic diagram of a stent 10 according to the present invention in a longitudinal cross section according to another embodiment, including a frame portion 32. The stent 10 is depicted in an assembled state excluding the porous layer 16, which defines the outer shape of the stent 10 in the assembled state. As shown, the mesh-like frame portion extends circumferentially around one longitudinal end of the stent body, and in this non-limiting example, has a mushroom-like or toroidal shape. The longitudinal end of the stent body is therefore surrounded by and housed within the frame portion 32.

[0092] As shown, the frame portion 32 has a shape that matches the shape of the portion of the stent body that is housed therein. This allows the frame portion 32 to be in direct contact with the stent body or even be integrated into the stent body. The overall shape of the longitudinal ends is mushroom-shaped or toroidal, allowing the longitudinal end faces of the porous layer to abut against the longitudinal ends. This limits inadvertent longitudinal movement of the porous layer and also provides an improved seal at the corresponding longitudinal end faces of the porous layer.

[0093] In this embodiment, the portion of the stent body surrounded by the frame portion 32 represents approximately 10% to 15% of the total length of the stent body. However, it will be understood that this percentage may vary depending on the particular application of the stent 10. Having an extended portion of the stent body not surrounded by the frame portion 32 may be advantageous, for example, in applications close to the rectum or sphincter, where the portion extending outside the patient may have an overall reduced stiffness compared to the portion surrounded by the frame portion 32. For such outer portions, covering the longitudinal end surfaces of the porous layer is considered optional.

[0094] FIG. 5 shows another embodiment of a stent 10 according to the present invention, including a frame portion 32; the porous layer is not shown for illustrative purposes. However, the porous layer can similarly be disposed around the frame portion 32 and the wall 12 of the stent body to substantially form the exterior of the stent 10. In this embodiment, the portion of the stent body surrounded by the frame portion 32 represents approximately 40% to 60% of the total length of the stent body. Furthermore, the overall length of the stent body and stent 10 is reduced compared to the embodiment depicted in FIG. 4. At the longitudinal ends of the stent body not surrounded by the frame portion 32, the stent body or its wall 12 defines flange-like extensions 34. Such flange-like extensions 34 are particularly advantageous for rectal applications, where outward extensions of the stent body must be avoided or limited. This also reduces potential discomfort to the patient. The flange-like extensions 34 can be specifically dimensioned to contact the sphincter or anus, thereby supporting the anchoring and proper placement of the stent 10. Furthermore, the flange-like extensions 34 can form covers on the longitudinal end faces of the porous layer, so that this embodiment can provide improved sealing within hollow organs.

[0095] It will be apparent to those skilled in the art that these embodiments and items merely represent examples of multiple possibilities. Therefore, the embodiments shown herein should not be understood to form limitations on these features and configurations. Any possible combination and configuration of the described features can be selected in accordance with the scope of the present invention. [List of reference numbers] 10 Stents 12 Wall 14 Passage 16 Porous layer 18 End face 20 Cover 22 Cannula 24A Distal opening of cannula (22) 24B, 24C Openings in the wall of the cannula (22) 26A Proximal Longitudinal End 26B Distal longitudinal end 28 Entrance opening of cover for cannula 30 additional cannulas for rinsing and cleaning 32 Frame part 34 Flange-like extension [Brief explanation of the drawings]

[0096] [Figure 1] 1 shows a schematic view of a stent according to the invention in longitudinal cross section. [Figure 2] 1 shows a schematic view of a stent according to the invention in longitudinal cross section according to another embodiment. [Figure 3] 1 shows a schematic representation of a method procedure for manufacturing a stent according to the present invention. [Figure 4] 1 shows a schematic view of a stent according to the invention in longitudinal cross section according to another embodiment with a frame portion. [Figure 5] 1 shows a schematic view of a stent according to the invention in longitudinal cross section according to another embodiment with a frame portion.

Claims

1. A stent (10) for introduction into a hollow organ of the human or animal body, preferably into the gastrointestinal tract, in particular into the intestine, comprising: a stent body having a wall (12), preferably radially resilient, defining an internal fluid passageway (14) from one end of the stent body to an opposite longitudinal end of said stent body; an elastic porous layer (16) covering the outer surface of the wall (12) along the entire circumference and along a predetermined cross section in the longitudinal direction of the stent body; the porous layer (16) and the wall (12) are adapted to apply negative pressure to the hollow organ implantation site; the wall (12) forms a fluid-tight barrier separating the internal fluid passage (14) and the porous layer (16); A stent (10) in which at least the longitudinally opposing end faces (18) of the porous layer (16) are covered by liquid-tight covers (20) connected to the respective longitudinal ends of the wall (12).

2. 2. The stent (10) of claim 1, wherein at least one longitudinal end (26A, 26B) of the porous layer (16) and the at least one cover (20) thereof are configured to accommodate at least one cannula (22).

3. The stent (10) of claim 1 or 2, further comprising at least one cannula (22) housed by the porous layer (16) on the outside of the wall (12).

4. 4. The stent (10) of claim 3, wherein the distal opening (24) of the cannula (22) is positioned between the opposing longitudinal ends (26A, B) of the porous layer (16), preferably within a cross section of the porous layer (16) adjacent to the distal longitudinal end (26B) of the porous layer (16).

5. The stent (10) according to any one of claims 2 to 4, wherein at least one cannula (22) is adapted to apply a negative pressure.

6. The stent (10) according to any one of claims 2 to 5, wherein the at least one additional cannula (30) is configured for rinsing and / or cleaning.

7. A stent (10) according to any one of claims 1 to 6, wherein the outer periphery of the porous layer (16) is covered with the cover (20) at the longitudinal ends (26A, B) of the porous layer (16).

8. The stent (10) according to any one of claims 1 to 7, wherein the wall (12) of the stent body and / or the porous layer (16) are made of a plastic material or a rubber material.

9. A stent (10) according to any one of claims 1 to 8, wherein the wall (12) of the stent body and / or the porous layer (16) are formed from a silicone-based material, preferably a material containing or consisting of silicone.

10. The stent (10) of any one of claims 1 to 9, wherein the wall (12) of the stent body and the porous layer (16) are made of the same material.

11. 11. The stent (10) of claim 10, wherein the porous layer (16) is formed of a foamed material having a lower density than the wall (12) of the stent body.

12. 12. The stent (10) of claim 10 or 11, wherein the wall (12) of the stent body and the porous layer (16) are integrally formed.

13. The stent (10) according to any one of the preceding claims, wherein the wall (12) of the stent body and the porous layer (16) are fixed to each other in a materially bonded manner.

14. A stent (10) according to any one of claims 1 to 13, wherein the cover (20) extends from each longitudinal end of the wall (12) as a sheet of material.

15. The stent (10) according to any one of the preceding claims, wherein the cover (20) and the wall (12) of the stent body are integrally formed.

16. 16. The stent (10) of claim 14 or 15, wherein the cover (20) is thinner than the wall (12) of the stent body.

17. The stent (10) according to any one of the preceding claims, wherein the cover (20) is provided in a materially bonded manner with the wall (12) and the porous layer (16) of the stent body.

18. The stent (10) of any one of claims 1 to 17, wherein the longitudinally opposed ends (26A,B) of the porous layer (16) comprise enlarged radially outward extensions.

19. 19. The stent (10) of claim 18, wherein in a longitudinal cross section of the porous layer (16), each respective end (26A, B) has a mushroom, dome, toroidal, or donut shape, and / or the porous layer (16) has a barbell shape.

20. A stent (10) according to any one of the preceding claims, comprising a mesh-like frame portion (32) surrounding only a portion of the stent body.

21. 21. The stent (10) of claim 20, wherein the frame portion (32) surrounds or contacts only one of the opposing longitudinal ends of the stent body.

22. 22. The stent (10) of claim 20 or 21, wherein the portion of the stent body surrounded by the frame portion (32) is between 40% and 60% of the length of the stent body.

23. 1. A method for manufacturing a stent (10) suitable for introduction into a hollow organ of the human or animal body, preferably into the gastrointestinal tract, in particular into the intestine, comprising: providing a radially fluid-tight barrier-defining wall (12) of a stent body, the wall (12) being preferably radially resilient and defining an internal fluid passageway (14) from one end of the stent body to an opposing longitudinal end of said stent body; providing a resilient porous layer (16); covering the outer surface of the wall (12) along the entire circumference of the wall (12) and along a predetermined cross section in the longitudinal direction of the stent body together with the porous layer (16); and covering at least the longitudinally opposing end faces (18) of the porous layer (16) with liquid-tight covers (20) connected to the longitudinal ends of each of the walls (12), A method for manufacturing a stent (10), wherein the porous layer (16) and the wall (12) are adapted to apply a negative pressure to a portion of the hollow organ.

24. the porous layer (16) and the wall (12) of the stent body are formed of the same material; 24. A method according to claim 23, wherein the porous layer (16) is provided by foaming the material to obtain a layer having a lower density than the wall (12) of the stent body.

25. the wall (12) and porous layer (16) of the stent body are integrally formed; and / or 25. The method of claim 23 or 24, wherein the wall (12) of the stent body and the porous layer (16) are fixed to each other by a material bond.

26. The manufacturing method according to any one of claims 23 to 25, wherein the cover (20) is formed as a sheet-like longitudinal extension of the wall (12) and is folded around each longitudinal end (26A, 26B) of the porous layer (16) to cover at least each end face (18) of the porous layer (16).

27. 26. The method of any one of claims 23 to 25, wherein the cover (20) is applied by dipping each end face (18) of the porous layer (16) and each longitudinal end of the wall (12) into the cover material (20).

28. 28. The method according to any one of claims 23 to 27, wherein a cannula (22) is located in the space between the wall (12) and the porous layer (16) and / or inserted into the porous layer (16).

29. The cannula (22) is secured by one or more sutures. by applying adhesive to each end face (18) of the porous layer (16) that houses the cannula (22); and / or by the interference fit provided by said porous layer (16); and / or 29. The method of claim 28, wherein the porous layer (16) containing the cannula (22) is secured to the stent body by the cover (20) at each end face (18) of the porous layer (16).

30. 30. The method of any one of claims 23 to 29, further comprising the step of providing a mesh frame portion (32) and optionally positioning said mesh frame portion (32) such that only a portion of said stent body is surrounded by said mesh frame portion (32).

31. 31. The method of claim 30, wherein the mesh frame portion (32) is positioned around the stent body prior to the step of covering the outer surface of the wall (12) with the porous layer (16) such that the mesh frame portion (32) is at least partially positioned between the porous layer (16) and the wall (12) of the stent body.

32. 1. A method for sealing a leak or a lesion in a hollow organ of the human or animal body, preferably in the gastrointestinal tract, especially intestinal, comprising: (a) introducing a stent according to any one of claims 1 to 22 into a hollow organ, thereby allowing the stent to cover the leak or lesion; (b) applying subnormal pressure to the target implantation site of the stent through the cannula, thereby adsorbing the hollow organ to the porous layer at the target implantation site; The method wherein the stent comprises at least one cannula housed by the porous layer on the outside of the wall or in the space between the wall of the stent and the porous layer.

33. 33. The method of claim 32, wherein the stent is introduced into the hollow organ in a compressed state and deployed at the target implantation site in the hollow organ using a catheter and / or an endoscope.

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