Porous medical device and method of use

Abstract

A medical system includes a tube defining a lumen and a porous body coupled to a distal end of the tube for advancement to a target site within a subject, the porous body defining a plurality of openings communicating with the lumen, the porous body containing a first substance and a second substance, the second substance eluting from the porous body into the subject.

Description

[Technical Field]

[0001] The present disclosure relates to minimally invasive (e.g., endoscopic and / or laparoscopic) medical devices and related methods of use. In embodiments, the present disclosure relates to one or more devices for removing fluids, debris, and other material from perforations, leaks, or wounds in the gastrointestinal tract, methods for forming such devices, and related methods of use. [Background technology]

[0002] Endoscopic and open surgical procedures of the gastrointestinal (GI) tract include, for example, colectomy, bariatric surgery, esophagectomy, gastric bypass, and sleeve gastrectomy. These procedures can result in tract perforation, postoperative leaks, or other wounds. Such wounds carry significant morbidity and mortality rates, and limited treatment options exist to address the wounds. Options include surgical re-incision and endoscopic placement of stents or clips. Surgery is relatively invasive and carries significant morbidity and mortality rates. Endoscopic stent placement is a minimally invasive option. However, placed stents may migrate from their planned location and / or may prevent infection and inhibit drainage at the treatment site. Summary of the Invention

[0003] According to an aspect, a medical system includes a tube defining a lumen and a porous body coupled to a distal end of the tube and configured to be advanced to a target site within a subject, the porous body defining a plurality of openings communicating with the lumen, the porous body including a first substance and a second substance configured to elute from the porous body into the subject.

[0004] The first material may include a polymer and the second material may include one or more growth factors or antibiotics.

[0005] The first material may include a hygroscopic material, and the porous body may be configured to be in a compressed state during insertion into the target site.

[0006] The porous body may be configured to expand from the compressed state to an expanded state when the porous body contacts a fluid.

[0007] The first material may include a thermally responsive material, and the porous body may be configured to be in a compressed state during insertion into the target site.

[0008] The porous body may be configured to expand from the compressed state to an expanded state when the porous body is heated to a temperature above a temperature threshold.

[0009] The plurality of openings can be disconnected from one another when the porous body is in the compressed state, and the plurality of openings can be connected when the porous body expands from the compressed state to the expanded state.

[0010] The porous body may contain nanoparticles that have antibacterial properties.

[0011] The plurality of openings may be formed using a crystalline material, and the size and shape of the openings may be approximately equal to the size and shape of crystals of the crystalline material.

[0012] The system may further include a vacuum source, which may be coupled to the tube and configured to provide a negative pressure to the lumen and porous body of the tube.

[0013] According to another aspect, a method of manufacturing the system may include mixing a polymer with a reagent to form a mixture, forming the porous body using the mixture, and attaching the porous body to the tube using one or more sutures, adhesives, or by forming the porous body directly on the tube.

[0014] The porous body may be formed using one or more three-dimensional (3D) printing or electrospinning techniques.

[0015] The plurality of openings may have a diameter of from about 50 μm to about 1 mm.

[0016] The method may further comprise coating the porous body with an antimicrobial substance.

[0017] The method may further comprise compressing the porous body from an expanded configuration to a compressed configuration after the porous body is attached to the tube.

[0018] According to yet another embodiment, a method of producing a porous body for a medical system comprises forming a mixture of a water-insoluble material and a water-soluble material, hardening the mixture, immersing the hardened mixture in a water bath, and removing a scaffold from the water bath, wherein the scaffold comprises the water-insoluble material.

[0019] Immersing the curing mixture in the water bath allows for the formation of a plurality of openings in the scaffold to form the porous body.

[0020] The water-soluble substance may include crystals, and the size of the plurality of openings may be substantially equal to the size of the crystals.

[0021] The method may further comprise coating the scaffold with a plurality of nanoparticles comprising an antimicrobial agent.

[0022] The method may further comprise dehydrating the scaffold and transforming the scaffold from an expanded configuration to a compressed configuration. [Brief explanation of the drawings]

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and, together with the description, serve to explain the principles of the disclosed embodiments.

[0024] [Figure 1] 1 is a schematic diagram of an endoluminal vacuum therapy (EVAC) system according to an embodiment.

[0025] [Figure 2] 2 is a schematic diagram of the EVAC system of FIG. 1 positioned within a body, according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0026] For ease of description, portions of the disclosed devices and / or their components are referred to as proximal and distal portions. Note that the term "proximal" is intended to refer to the portion of the device closest to the user, and the term "distal" is used herein to refer to the portion away from the user. Similarly, "extends distally" indicates that a component extends in the distal direction, and "extends proximally" indicates that a component extends in the proximal direction. Additionally, as used herein, the terms "about," "approximately," and "substantially" indicate a range of values ​​within + / - 10% of the stated or implied value. Terms indicating component / surface geometries indicate exact and approximate shapes. The present disclosure may be understood with reference to the following description and accompanying drawings, in which like elements are designated with the same reference numerals.

[0027] Endoluminal vacuum therapy (EVAC) has been proposed. In EVAC, negative pressure is delivered to a wound site in the GI tract, for example, via a nasogastric tube terminated in a sponge or porous material. The sponge is placed endoscopically into the perforation, leak, or other wound. Negative pressure is then applied. However, devices and systems suitable for EVAC are limited.

[0028] Embodiments of the present disclosure include devices, systems, and methods for endoluminal vacuum therapy (EVAC), and device configurations for performing EVAC. In examples, EVAC involves the endoluminal placement of a sponge or other similar material within a wound site (e.g., a target site), including a perforation, cyst, leak, anastomosis, etc. The placement of the material may be performed by a catheter, scope (e.g., endoscope, bronchoscope, colonoscope, duodenoscope, gastroscope, etc.), tube, or sheath inserted into the GI tract through a natural orifice. The orifice may be, for example, the nose, mouth, or anus, and placement may be in any part of the GI tract, including the esophagus, stomach, duodenum, large intestine, or small intestine. The placement of the material may also be in other tissues accessible through the GI tract (e.g., the pancreas).

[0029] FIG. 1 illustrates the distal end of an EVAC system 10 according to an example of the present disclosure. The system 10 can be inserted into a patient for the treatment of chronic wounds using negative vacuum pressure. The system 10 generally includes a sponge 30 (or other reticulated or porous material) and a vacuum tube 40. The sponge 30 is attached to the distal end of the vacuum tube 40. The vacuum tube 40 can include an outer wall 42 defining one or more lumens 44. The lumens 44 are open at both the proximal and distal ends of the vacuum tube 40. The outer wall 42 can include multiple holes around the circumference of the distal end of the vacuum tube 40 and can communicate with the lumens 44 to increase the flow of fluids or substances within the lumens 44, as described herein. The distal end of the vacuum tube 40 can be attached to the sponge 30 by sutures, adhesive, or the like. In some examples, a recess (not shown) can be provided in the sponge 30 to receive the distal end of the vacuum tube 40. The vacuum tube 40 may be mounted within a recess in the sponge 30 to provide additional structural support between the sponge 30 and the vacuum tube 40. Alternatively, the sponge 30 may be formed over the vacuum tube 40, as described herein. The proximal end of the vacuum tube 40 may be connected to a vacuum source (not shown) to provide negative pressure to the sponge 30. For example, a negative pressure of approximately 125 mmHg (16.7 kPa), or approximately 2.5 pounds per square inch (PSI) (17.2 kPa), may be provided to the sponge 30. Other suitable amounts of negative pressure may be used. This negative pressure may draw fluids, substances, and / or other debris through the openings 32 and into the lumen 44 of the vacuum tube 40 to promote healing of the target site 70 (FIG. 2).

[0030] The sponge 30 may include openings 32 on its outer surface. The openings 32 may be any holes, pores, or channels that provide continuous access to the interconnecting channels and pores throughout the sponge 30. The openings 32 may include different sizes and shapes and may be selected based on the location of treatment within the body. For example, the openings 32 may be spherical, cubic, irregular, or any other shape. The size of the openings 32 may be approximately 50 μm to approximately 1 mm in diameter. While the sponge 30 is shown as being spherical, it may be any shape, including cylindrical, cubic, or irregular. As described herein, the sponge 30 may also include a substance (e.g., a reagent) that elutes from the sponge 30 when the sponge 30 is placed at the target site 70. By way of example, the reagents may elute at different rates and may be customizable based on various factors, including the expected lifespan of the sponge 30, the length of time before the sponge 30 must be replaced with a new sponge 30, etc. Additionally or alternatively, the sponge 30 may be coated with nanoparticles having microbial properties, including silver nanoparticles, which may improve the activity of substances eluted from the sponge 30 by altering the membrane permeability of cells and / or enhancing drug delivery.

[0031] An example of system 10 positioned within a target site 70 within the body is shown in Figure 2. A sponge 30 is positioned within the target site 70. The distal end of a vacuum line 40 is attached to the sponge 30 and extends proximally into the GI tract 80 and outside the body. A vacuum source (not shown) may be attached to the proximal end of the tract 40 to provide negative pressure to the lumen 44 and sponge 30 to draw fluids and matter from the target site 70.

[0032] A method for forming the sponge 30 is described. By way of example, the sponge 30 may be formed by electrospinning. Additional substances, such as growth factors, antibiotics, and / or other treatment-improving substances, may be mixed with the scaffold material prior to electrospinning the sponge 30. Unlike conventional stents, which are coated with growth factors or antibiotics after the stent is formed, the material used to form the scaffold (e.g., polymer) of the sponge 30 is mixed with the growth factors or antibiotics, including any substances that may promote healing and / or inhibit the growth of microorganisms (e.g., harmful microorganisms), before the scaffold is generated. The ratio of the eluting substance to the material used to form the sponge 30 may be approximately 1:5 to 1:20. By way of example, the mixture of polymer and eluting substance may be electrospun to form the sponge 30 having openings 32 communicating with the channels.

[0033] The sponge 30 may be post-processed by cutting the sponge into various shapes as described herein. Additional post-processing may include introducing recesses into the sponge 30 into which the vacuum tube 40 may be introduced and secured, for example, with adhesive, sutures, or the like. The sponge 30 may also be cut approximately in half, and channels may be formed on each side of the sponge 30 to accommodate the bifurcated ends of the vacuum tube 40. The bifurcated ends of the vacuum tube 40 may rest within the channels, and the sponge 30 may be reassembled using, for example, adhesive, sutures, or the like. The bifurcations in the tube 40 may provide additional pathways by which fluids and / or substances wicked by the sponge 30 may enter the lumen 44, which may decrease healing time at the target site 70. It will be understood that this post-processing step may be performed after any method of forming the sponge 30.

[0034] According to another embodiment, the sponge 30 may be formed using a polymer and / or polymer mixture (e.g., including a polymer and one or more eluting substances) and may be formed into the sponge 30 by casting or three-dimensional (3D) printing. By way of example, a 3D printer may be programmed to produce the polymer mixture in a pattern that forms a plurality of openings, holes, or pores 32 in the sponge 30. In this manner, the shape and / or size of the openings may be controlled. A mold may be used to cast the sponge 30 with the openings. Mold casting and / or 3D printing of the sponge 30 may form a plurality of openings, holes, or pores 32 of substantially uniform shape and / or size in the sponge 30.

[0035] According to yet another embodiment, the sponge 30 may comprise a hygroscopic material such as hydrogel, cellulose, or other superabsorbent polymers such as poly(N-isopropylacrylamide) (PNIPAM), copolymers of PNIPAM, polyacrylic acid, polyacrylamide, polyurethane foam, polyacrylic acid and polyacrylate, carboxymethylcellulose, partially crosslinked water-swellable polymers such as polyethylene oxide and polyacrylamide, and isobutylene maleic acid copolymers. The sponge 30 may be formed using any of the methods described herein and, in some cases, may include one or more additives. These substances may be introduced into the sponge 30 in a low-profile or compressed state by dehydrating the sponge 30 prior to insertion into the body. Once inserted, the sponge 30 may expand when contacted with fluid. For example, fluid may be introduced into the sponge 30 at the target site 70 through a catheter or other related tool, or through the lumen 44. Alternatively, or additionally, fluid at the target site 70 may aid in the expansion of the sponge 30 from a dehydrated state to an expanded state. Once the sponge 30 is expanded, fluid may be removed from the target site 70 using the vacuum tube 40.

[0036] According to another embodiment, the sponge 30 may comprise a thermoresponsive polymer, such as poly(N-isopropylacrylamide) (PNIPAM), copolymers of PNIPAM, polyacrylic acid, and / or polyacrylamide. Similar to sponges 30 comprising hygroscopic materials, sponges 30 comprising thermoresponsive polymers may expand from a low-profile or compressed state. Prior to expansion, the sponge 30 may be compressed such that the openings 32 are closed and / or compressed, thereby preventing the openings 32 from communicating. When the sponge 30 is introduced to the target site 70, heating from the body may cause the sponge 30 to expand to an expanded state when the sponge 30 is heated above a temperature threshold of approximately 30°C or approximately 35°C. The temperature threshold is not limited to these temperatures and may be modified by copolymerization of the sponge 30 with other polymers and / or the incorporation of various substances that elute from the sponge 30. Once the sponge 30 expands, the openings 32 communicate, allowing fluid to be received by the sponge 30. It will be understood that the material is not limited to thermoresponsive or hygroscopic materials. In some embodiments, the material of the sponge 30 may utilize the pH of the body, chemicals produced in the body (e.g., at the target site 70), and / or any other properties of the material of the sponge 30 to expand the sponge 30 from a compressed state to an expanded state.

[0037] Another example of forming a sponge can involve saturating a material with crystals. For example, any water-insoluble material, such as silicone, and / or any material containing variable mechanical properties, such as flexibility or rigidity, can be mixed with water-soluble crystals, such as sugar, salt, or any material containing crystals that are water-soluble but insoluble in non-organic solvents. For example, Sylgard silicone can be mixed with 10% by weight of a crosslinker to form a silicone mixture. This silicone mixture is insoluble in water. The silicone mixture can then be mixed with a water-soluble material. The ratio of water-insoluble material to water-soluble material is approximately 50% by weight. Once the water-insoluble material is fully saturated with the water-soluble material, the mixture can be cured, for example, using a curing oven. Alternatively, the mixture can be formed into any shape that sinks to the bottom of a mixing vessel, for example, forming a shape corresponding to the shape of the mixing vessel. Once the mixture has hardened or sunk to the bottom of the mixing vessel, the cured mixture resulting from the water-insoluble material and the water-soluble material can be placed in a water bath. The water may be at about 50°C to about 100°C, and the setting mixture may remain in the water bath for about 12 hours. During this time, the water dissolves substantially all of the water-soluble material, forming pores, channels, and / or openings 32 in the sponge 30 in the areas where the water-soluble material was dissolved. The size and shape of these pores, channels, and / or openings 32 approximately correspond to the size and shape of the water-soluble material crystals. Once the water-soluble material is dissolved, the sponge 30 may be flexible and / or compressible.

[0038] A method of using the system 10 will now be described. The sponge 30 may be introduced through an orifice (e.g., a natural orifice) and advanced to the target site 70 using a catheter or other known mechanism. Once the sponge 30 is positioned at the target site 70, a fluid may be supplied to the sponge 30, for example, via a catheter. Alternatively, the fluid at the target site 70 may activate and expand the sponge 30. In situations where the sponge 30 includes a heat-activated material, the sponge 30 may expand when heated above a temperature threshold by the body at the target site 70. Once the sponge 30 has expanded from the compressed state to the expanded state, the vacuum tube 40 may be attached to a vacuum source, and a negative pressure of approximately 125 mmHg (16.7 kPa), or approximately 2.5, may be supplied to the sponge 30.

[0039] It will be understood that any of the materials, coatings, or eluting substances described herein may be used alone or in combination to form a medical sponge. It will also be understood that any of the features of the sponges described herein may be used with any other EVAC system and / or any other medical system.

[0040] While various medical systems are described, it will be understood that the specific arrangement of elements in these systems is not limited. Furthermore, the size, shape, and / or material of the sponge in the EVAC system is not limited. The sponge is used to access and treat target sites inside or outside the lumen of the GI tract. For example, in certain procedures, performing various medical procedures may be improved by using a sponge with substances such as growth hormones and / or antibiotics that are eluted from the sponge at the target site to prevent infection or other medical problems, e.g., in organs outside the GI tract.

[0041] It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed devices without departing from the scope of the present disclosure. Other embodiments of the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

Claims

1. 1. A medical system comprising: a tube defining a lumen, the tube having a plurality of branched ends at a distal end thereof; a porous body coupled to the distal end of the tube and configured to be advanced to a target site within a subject, the porous body defining a plurality of openings and a plurality of channels, the plurality of openings communicating with the plurality of branched ends and the lumen, the porous body containing a first substance and a second substance, the second substance configured to elute from the porous body into the subject; A medical system, wherein each branch end of the plurality of branch ends is seated within a corresponding one of the plurality of channels.

2. 10. The medical system of claim 1, wherein the first substance comprises a polymer and the second substance comprises one or more growth factors or antibiotics.

3. 3. The medical system of claim 1 or claim 2, wherein the first material comprises a hygroscopic material and the porous body is configured to be in a compressed state during insertion into the target site.

4. The medical system of claim 3 , wherein the porous body is configured to expand from the compressed state to an expanded state when the porous body contacts a fluid.

5. 3. The medical system of claim 1 or claim 2, wherein the first material comprises a thermoresponsive material, and the porous body is configured to be in a compressed state during insertion into the target site.

6. The medical system of claim 5 , wherein the porous body is configured to expand from the compressed state to the expanded state when the porous body is heated to a temperature above a temperature threshold.

7. The medical system according to claim 4 or claim 6, wherein the plurality of openings are not connected when the porous body is in the compressed state, and the plurality of openings are connected when the porous body expands from the compressed state to the expanded state.

8. The medical system according to any one of claims 1 to 7, wherein the porous body contains nanoparticles having antibacterial properties.

9. 9. The medical system of claim 1, further comprising a vacuum source coupled to the tube and configured to apply negative pressure to the lumen and porous body of the tube.

10. 10. A method for manufacturing the medical system of any one of claims 1 to 9, comprising: mixing the polymer with the reagent to form a mixture; forming the porous body using the mixture, the porous body defining a plurality of openings; forming a channel in the porous body, the channel communicating with the opening; and attaching the porous body to the distal end of the tube using one or more sutures or adhesive, the bifurcated end of the tube being resting within a channel of the porous body.

11. 11. The method of claim 10, wherein the porous body is formed using one or more three-dimensional (3D) printing or electrospinning techniques.

12. 12. The method of claim 10 or claim 11, wherein the plurality of openings have a size of about 50 μm to about 1 mm in diameter.

13. 13. The method of any one of claims 10 to 12, further comprising coating the porous body with an antimicrobial substance.

14. 14. The method of any one of claims 10 to 13, further comprising compressing the porous body from an expanded configuration to a compressed configuration after the porous body is attached to the distal end of the tube.

15. The medical system according to claim 1 , wherein the first substance expands the porous body from a compressed state to an expanded state in response to pH in the subject's body.

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