HK1134048A - System for administering reduced pressure treatment having a manifold with a primary flow passage and a blockage prevention member - Google Patents

Abstract

A reduced pressure delivery system is provided and includes a primary manifold, a blockage prevention member, and first and second conduits in fluid communication with the primary manifold. The primary manifold includes a flexible wall surrounding a primary flow passage and is adapted to be placed in proximity to a tissue site. The blockage prevention member is positioned within the primary flow passage. A plurality of apertures is disposed in the flexible wall to communicate with the primary flow passage. The first conduit is fluidly connected to the primary flow passage to deliver reduced pressure through the primary flow passage and the plurality of apertures. The second conduit includes an outlet proximate the primary flow passage or an outlet of the first conduit to purge the primary flow passage or first conduit to prevent blockages.

Description

System for administering reduced pressure treatment having a manifold with a primary flow passage and an occlusion prevention member

Background

1. Field of the invention

The present invention relates generally to systems or methods for promoting tissue growth, and more particularly to systems for applying reduced pressure tissue treatment to a tissue site.

2. Description of the related Art

Reduced pressure therapy is increasingly being used to promote wound healing in soft tissue wounds that heal slowly or do not heal without reduced pressure therapy. Generally, the reduced pressure is applied to the wound site through an open-cell foam that serves as a manifold (maniffold) that distributes the reduced pressure. Open-cell foams are sized to fit an existing wound, placed in contact with the wound, and then replaced periodically with smaller foam blocks as the wound begins to heal and become smaller. Frequent replacement of open-cell foam is necessary to minimize the amount of tissue that grows into the pores of the foam. Considerable tissue in-growth can cause pain to the patient during foam removal.

Reduced pressure treatment is generally applied to open wounds that do not heal. In some cases, the healing tissue is located subcutaneously, while in other cases, the tissue is located in or on skin tissue. Traditionally, reduced pressure treatment has been applied primarily to soft tissues. Reduced pressure therapy is not generally used to treat closed, deep tissue wounds because of the difficulty in accessing such wounds. In addition, reduced pressure therapy is not used in the treatment of bone defects or in the promotion of bone growth, primarily due to access problems. Surgically exposing bone to the application of reduced pressure therapy may create more problems than it solves. Finally, devices and systems for applying reduced pressure treatment are a little more advanced than open-cell foam blocks that are manually shaped to fit the wound site and then removed after a reduced pressure treatment period.

Summary of The Invention

The problems posed by existing wound healing systems and methods are addressed by the systems and methods of the present invention. A reduced pressure delivery system is provided according to one embodiment of the invention to apply a reduced pressure to a tissue site. The reduced pressure delivery system includes a primary manifold (primary manifold) having a flexible wall surrounding a primary flow passage (primary flow passage) and adapted to be disposed adjacent a tissue site. The flexible wall includes an inner surface having a plurality of projections extending from at least a portion of the inner surface and into the primary flow passage. The flexible wall further includes a plurality of apertures extending through the flexible wall in communication with the primary flow passage. The first conduit is fluidly connected to the primary flow passage to communicate the reduced pressure through the primary flow passage and the plurality of apertures. The second conduit includes at least one outlet positioned adjacent to the primary flow passage or the at least one outlet of the first conduit to clear obstructions at or near the at least one outlet of the first conduit.

In accordance with another embodiment of the present invention, a reduced pressure delivery system is provided and includes a primary manifold having a flexible wall surrounding a primary flow passage and adapted for placement adjacent a tissue site. The flexible wall further includes a plurality of apertures extending through the flexible wall in communication with the primary flow passage. The cellular material is located within the primary channel and the cellular material includes a plurality of flow channels. The first conduit is fluidly connected to the primary flow passage to convey the reduced pressure through the primary flow passage, the cellular material, and the plurality of apertures. The second conduit includes at least one outlet positioned adjacent to the primary flow passage or the at least one outlet of the first conduit to clear obstructions at or near the at least one outlet of the first conduit.

In accordance with yet another embodiment of the present invention, a reduced pressure delivery system is provided and includes a primary manifold having a flexible wall surrounding a primary flow passage and adapted for placement adjacent a tissue site. The primary manifold includes a blockage prevention member located within the primary flowpath. A plurality of apertures are disposed within the flexible wall to communicate with the primary flow passage. A secondary manifold is disposed adjacent the primary manifold and is adapted to contact the tissue site such that the secondary manifold is in fluid communication with the primary manifold, but is adapted to prevent contact between the primary manifold and the tissue site. The first conduit is fluidly connected to the primary flow passage to communicate the reduced pressure through the primary flow passage and the plurality of apertures.

In another embodiment of the present invention, a method for promoting tissue growth at a tissue site includes placing a primary manifold near the tissue site. The primary manifold includes a flexible wall surrounding a primary flow passage. The flexible wall includes a plurality of apertures therethrough in communication with the primary flow passage. The primary manifold further includes a blockage prevention member located within the primary flow passage. The method further includes surgically placing the secondary manifold in contact with the tissue site such that the secondary manifold is in fluid communication with the primary manifold, but contact between the primary manifold and the tissue site is prevented. The reduced pressure is delivered to the tissue site through the primary channel, the plurality of apertures, and the secondary manifold.

Other objects, features and advantages of the present invention will become apparent with reference to the drawings and the following detailed description.

Brief Description of Drawings

This patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the office upon request and payment of the necessary fee.

FIG. 1 depicts a perspective view of a reduced pressure delivery apparatus having a plurality of projections extending from a flexible barrier (flexible barrier) to create a plurality of flow channels, according to an embodiment of the present invention;

FIG. 2 illustrates a front view of the reduced pressure delivery apparatus of FIG. 1;

FIG. 3 depicts a top view of the reduced pressure delivery apparatus of FIG. 1;

FIG. 4A illustrates a side view of the reduced-pressure delivery apparatus of FIG. 1 having a reduced-pressure delivery tube;

FIG. 4B depicts a side view of an alternative embodiment of the reduced-pressure delivery apparatus of FIG. 1 having a dual lumen reduced-pressure delivery tube;

FIG. 5 illustrates an enlarged perspective view of the reduced pressure delivery apparatus of FIG. 1;

FIG. 6 depicts a perspective view of a reduced pressure delivery apparatus having a microporous material attached to a flexible barrier having a bulged section and a pair of wing sections, the microporous material having a plurality of flow passages, according to an embodiment of the invention;

FIG. 7 illustrates a front view of the reduced pressure delivery apparatus of FIG. 6;

FIG. 8 depicts a cross-sectional side view of the reduced-pressure delivery apparatus of FIG. 7 taken along XVII-XVII;

figure 8A illustrates a cross-sectional elevation view of a reduced pressure delivery apparatus according to an embodiment of the present invention;

FIG. 8B depicts a side view of the reduced pressure delivery apparatus of FIG. 8A;

figure 9 illustrates a front view of a reduced pressure delivery apparatus for applying reduced pressure tissue treatment to a patient's bone, according to an embodiment of the present invention;

FIG. 10 depicts a color tissue section of a rabbit skull showing untested, undamaged bone;

FIG. 11 shows a color tissue section of a rabbit skull showing the induction of granulation tissue after application of reduced pressure tissue treatment;

FIG. 12 depicts a color tissue section of a rabbit skull showing the deposition of new bone after application of reduced pressure tissue treatment;

FIG. 13 shows a color tissue section of a rabbit skull showing the deposition of new bone after application of reduced pressure tissue treatment;

FIG. 14 depicts a color photograph of a rabbit skull having two critical dimension defects formed in the skull;

FIG. 15 shows a color photograph of the rabbit skull of FIG. 14 showing a calcium phosphate scaffold inserted within one critical size defect and a stainless steel mesh (screen) covering a second critical size defect;

FIG. 16 depicts a color photograph of the rabbit skull of FIG. 14 showing application of reduced pressure tissue treatment to a critical-size defect;

FIG. 17 shows a colored tissue section of a rabbit skull after reduced pressure tissue treatment showing the deposition of new bone within the calcium phosphate scaffold;

FIG. 18 depicts a radiograph (radiogram) of a critical-size defect of the filled stent of FIG. 15 after six days of reduced pressure tissue treatment and two weeks post-surgery;

FIG. 19 shows a radiograph of a critical dimension defect of the filled stent of FIG. 15 after six days of reduced pressure tissue treatment and twelve weeks post-surgery;

figure 20 depicts a front view of a reduced pressure delivery system having a manifold delivery tube for percutaneously inserting a reduced pressure delivery apparatus to a tissue site, according to an embodiment of the present invention;

FIG. 21 shows an enlarged front view of the manifold delivery tube of FIG. 20 including a reduced pressure delivery apparatus having a flexible barrier and/or a microporous material in a compressed position;

FIG. 22 depicts an enlarged front view of the manifold delivery tube of FIG. 21, the flexible barrier and/or microporous material of the reduced pressure delivery apparatus shown in an expanded position after being pushed away from the manifold delivery tube;

figure 23 illustrates a front view of a reduced pressure delivery system having a manifold delivery tube for percutaneously inserting a reduced pressure delivery apparatus to a tissue site, the reduced pressure delivery apparatus shown external to the manifold delivery tube but confined in a compressed position by an impermeable membrane, according to an embodiment of the invention;

figure 24 depicts a front view of the reduced pressure delivery system of figure 23, the reduced pressure delivery apparatus shown outside of the manifold delivery tube, but restrained in a relaxed position by an impermeable membrane;

figure 25 illustrates a front view of the reduced pressure delivery system of figure 23, the reduced pressure delivery apparatus shown outside of the manifold delivery tube, but restrained in an expanded position by an impermeable membrane;

figure 25A illustrates a front view of the reduced pressure delivery system of figure 23, the reduced pressure delivery apparatus shown outside of the manifold delivery tube, but surrounded by an impermeable membrane in an expanded position;

figure 26 depicts a front view of a reduced pressure delivery system having a manifold delivery tube for percutaneously inserting a reduced pressure delivery apparatus to a tissue site, the reduced pressure delivery apparatus shown external to the manifold delivery tube but circumscribed by an impermeable membrane having a glue seal (glue seal), according to an embodiment of the present invention;

figure 26A depicts a front view of a reduced pressure delivery system according to an embodiment of the invention;

figure 27 illustrates a front view of a reduced pressure delivery system having a manifold delivery tube for percutaneously inserting a reduced pressure delivery apparatus to a tissue site, according to an embodiment of the present invention;

figure 27A illustrates a front view of a reduced pressure delivery system having a manifold delivery tube for percutaneously inserting a reduced pressure delivery apparatus to a membrane impermeable membrane at a tissue site, according to an embodiment of the present invention;

figure 28 depicts a flowchart of a method of administering reduced pressure tissue treatment to a tissue site according to an embodiment of the invention;

figure 29 illustrates a flow diagram of a method of administering reduced pressure tissue treatment to a tissue site, according to an embodiment of the invention;

figure 30 depicts a flow diagram of a method of administering reduced pressure tissue treatment to a tissue site according to an embodiment of the invention;

figure 31 illustrates a flow diagram of a method of administering reduced pressure tissue treatment to a tissue site, according to an embodiment of the invention;

figure 32 depicts a cross-sectional elevation view of a reduced pressure delivery apparatus including a hip prosthesis having a plurality of flow channels for applying reduced pressure to an area of bone surrounding the hip prosthesis, according to an embodiment of the present invention;

FIG. 33 shows a cross-sectional elevation view of the hip prosthesis of FIG. 32 having a second plurality of flow channels for delivering fluid to an area surrounding the bone of the hip prosthesis;

figure 34 depicts a flowchart of a method for repairing a joint of a patient using reduced pressure tissue treatment, according to an embodiment of the invention;

FIG. 35 illustrates a cross-sectional elevation view of a reduced pressure delivery apparatus including an orthopedic fixation device having a plurality of flow channels for applying reduced pressure to a region of bone adjacent the orthopedic fixation device, according to an embodiment of the present invention;

FIG. 36 depicts a cross-sectional elevation view of the orthopedic fixation device of FIG. 35 having a second plurality of flow channels for delivering fluid to a region of bone adjacent the orthopedic fixation device;

figure 37 illustrates a flow diagram of a method for healing a bone defect of a bone using reduced pressure tissue treatment, according to an embodiment of the present invention;

figure 38 depicts a flowchart of a method of administering reduced pressure tissue treatment to a tissue site according to an embodiment of the invention; and

figure 39 illustrates a flow diagram of a method of administering reduced pressure tissue treatment to a tissue site, according to an embodiment of the invention.

40-48 depict different views of a reduced pressure delivery system having a primary manifold including a flexible wall surrounding a primary flowpath and a plurality of apertures within the flexible wall, according to an embodiment of the present invention;

49-50 illustrate perspective and top cross-sectional views of a reduced pressure delivery system having a primary manifold integrally connected to a reduced pressure delivery tube, according to an embodiment of the present invention;

FIG. 51 depicts a perspective view of the primary manifold of FIGS. 40-50 applied to a bone tissue site with a secondary manifold; and

figure 52 illustrates a schematic view of a reduced pressure delivery system having a valve fluidly connected to a second conduit, according to an embodiment of the present invention.

Detailed description of the preferred embodiments

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the present invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.

As used herein, the term "elastic" means having the characteristics of an elastomer. The term "elastomer" generally refers to a polymeric material having rubber-like properties. More specifically, most elastomers have an elongation greater than 100% and considerable elasticity. The elasticity of a material refers to the ability of the material to recover from elastic deformation. Examples of elastomers may include, but are not limited to, natural rubber, polyisoprene, styrene butadiene rubber, chloroprene rubber, polybutadiene, nitrile rubber, butyl rubber, ethylene propylene diene monomer rubber, chlorosulfonated polyethylene, polysulfide rubber, polyurethane, and silicone.

As used herein, the term "flexible" refers to an object or material that is capable of bending or flexing. Elastomeric materials are generally flexible, but reference herein to flexible materials does not necessarily limit the choice of materials to only elastomers. The term "flexible" as used with respect to the materials or reduced pressure delivery apparatus of the present invention generally refers to the ability of the material to conform to or closely match the shape of the tissue site. For example, the pliable nature of a reduced pressure delivery apparatus for treating a bone defect may allow the apparatus to be wrapped or folded around a portion of bone having the defect.

As used herein, the term "fluid" generally refers to a gas or a liquid, but may also include any other flowable material including, but not limited to, gels, gums, and foams.

As used herein, the term "impermeable" generally refers to the ability of a membrane, cover, sheet, or other substance to block or slow the transmission of liquid or gas. Impermeable may be used to refer to a cover, sheet, or other membrane that resists the passage of liquid therethrough while allowing gas to pass through the membrane. While an impermeable membrane may be liquid impermeable, the membrane may simply reduce the permeability of all or only some liquids. The use of the term "impermeable" is not meant to imply that the impermeable membrane is above or below any particular industry standard measurement for impermeability, such as a particular value of Water Vapor Transmission Rate (WVTR).

As used herein, the term "manifold" generally refers to a substance or structure configured to facilitate the application of reduced pressure to, delivery of fluids to, or removal of fluids from a tissue site. The manifold generally includes a plurality of flow channels or paths that are interconnected to improve the distribution of fluid provided to and removed from the tissue region surrounding the manifold. Examples of manifolds may include, without limitation, devices having structural elements arranged to form flow channels, porous foams such as open-cell foams, porous tissue populations, and liquids, gels, and foams that include or are prepared to include flow channels.

As used herein, the term "reduced pressure" generally refers to a pressure less than ambient pressure at the tissue site being treated. In most cases, this reduced pressure is less than the atmospheric pressure at which the patient is located. Alternatively, the reduced pressure may be less than a hydrostatic pressure of tissue at the tissue site. While the terms "vacuum" and "negative pressure" may be used to describe the pressure applied to the tissue site, the actual pressure applied to the tissue site may be significantly less than the pressure typically associated with a complete vacuum. The reduced pressure may initially create fluid flow within the tube and in the region of the tissue site. When the hydrostatic pressure around the tissue site approaches the desired reduced pressure, the flow may subside, and the reduced pressure is then maintained. Unless otherwise indicated, the pressure values described herein are gauge pressures.

As used herein, the term "scaffold" refers to a substance or structure used to enhance or promote the growth of cells and/or the formation of tissue. Scaffolds are generally three-dimensional porous structures that provide a template for cell growth. The scaffold may be infused with, coated with, or contain cells, growth factors, or other nutrients to promote cell growth. The scaffold may be used as a manifold according to embodiments described herein to administer reduced pressure tissue treatment to a tissue site.

As used herein, the term "tissue site" refers to a wound or defect located on or within any tissue, including but not limited to bone tissue, adipose tissue, muscle tissue, neural tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendons, or ligaments. Moreover, the term "tissue site" may refer to an area of any tissue that is not necessarily wounded or defective, but may be an area where it is desired to add or promote the growth of additional tissue. For example, reduced pressure tissue treatment may be used in certain tissue regions to culture additional tissue that may be harvested and transplanted to another tissue location.

Referring to fig. 1-5, a reduced pressure delivery apparatus or winged manifold 211 in accordance with the principles of the present invention includes a flexible barrier 213 having a bulged portion 215 and a pair of wing portions 219. Each wing portion 219 is disposed along opposite sides of the spine portion 215. The raised portion 215 forms an arcuate channel 223 that may or may not extend the entire length of the wing manifold 211. Although the spine portion 215 may be centrally located on the wing manifold 211 such that the width of the wing portions 219 is equal, the spine portion 215 may also be offset as shown in fig. 1-5, resulting in one wing portion 219 being wider than the other wing portion 219. The extra width of one wing portion 219 may be particularly useful if the wing manifold 211 is used in connection with bone regeneration or healing, and the wider wing manifold 211 will wrap around a fixation member that is attached to the bone.

The flexible barrier 213 is preferably formed of an elastomeric material such as a silicone polymer. Examples of suitable siloxane polymers include MED-6015 manufactured by Nusil Technologies of Carpinteria, California. It should be noted, however, that the flexible barrier 213 may be made of any other biocompatible flexible material. The flexible barrier 213 includes a flexible backing 227 that increases the strength and durability of the flexible barrier 213. The thickness of the flexible barrier 213 including the flexible substrate 227 in the arcuate channel 223 may be less than the thickness in the wing portions 219. If a silicone polymer is used to form the flexible barrier 213, a silicone adhesive may also be used to help bond with the flexible substrate 227. An example of a silicone adhesive may include MED-1011, also sold by Nusil Technologies. The flexible substrate 227 is preferably made of a polyester knit fabric, such as Bard6013 manufactured by c.r. Bard of Tempe, Arizona. However, the flexible substrate 227 may be made of any biocompatible flexible material that can increase the strength and durability of the flexible barrier 213. In some cases, the flexible substrate 227 may be omitted if the flexible barrier 213 is made of a material of suitable strength.

Preferably, the flexible barrier 213 or the flexible substrate 227 is impermeable to liquid, air, and other gases, or alternatively, both the flexible substrate 227 and the flexible barrier 213 are impermeable to liquid, air, and other gases.

The flexible barrier 213 and flexible backing 227 may also be constructed of a bioresorbable material that does not have to be removed from the patient's body after use of the reduced pressure delivery apparatus 211. Suitable bioresorbable materials may include, without limitation, a polymeric blend of polylactic acid (PLA) and polyglycolic acid (PGA). The polymerization mixture may also include, without limitation, polycarbonate, polypropylene fumarate (polyfumarate), and caprolactone (capralactone). The flexible barrier 213 and the flexible substrate 227 may further serve as a scaffold for new cell growth, or a scaffold material may be used in conjunction with the flexible barrier 213 and the flexible substrate 227 to promote cell growth. Suitable scaffold materials may include, without limitation, calcium phosphate, collagen, PLA/PGA, coral hydroxyapatite, carbonate, or a treated allogeneic graft. Preferably, the scaffold material has a high porosity (i.e., high air content).

In one embodiment, the flexible backing 227 may be adhesively attached to the surface of the flexible barrier 213. If a silicone polymer is used to form the flexible barrier 213, a silicone adhesive may also be used to attach the flexible substrate 227 to the flexible barrier 213. While adhesive is the preferred method of attachment when the flexible substrate 227 is surface bonded to the flexible substrate 213, any suitable means of attachment may be used.

The flexible barrier 213 includes a plurality of projections 231 extending from the wing 219 on a surface of the flexible barrier 213. The projections 231 may be cylindrical, spherical, hemispherical, cubic, or any other shape so long as at least some portion of each projection 231 lies in a plane that is different from the plane associated with the side of the flexible substrate 213 to which the projections 231 are attached. In this regard, a particular projection 231 need not even have the same shape or size as other projections 231; indeed, the projections 231 may include a random mix of different shapes and sizes. Thus, the distance each projection 231 extends from the flexible barrier 213 may vary, but may be uniform among the plurality of projections 231.

The placement of the projections 231 on the flexible barrier 231 creates a plurality of flow channels 233 between the projections. When the projections 231 are of uniform shape and size and are evenly spaced across the flexible barrier 213, the flow channels 233 created between the projections 231 are similarly uniform. Variations in the size, shape, and spacing of the projections 231 may be used to vary the size and flow characteristics of the flow channels 233.

A reduced-pressure delivery tube 241 is positioned within the arcuate channel 223 and attached to the flexible barrier 213, as shown in fig. 5. The reduced-pressure delivery tube 241 may be attached to the flexible barrier 213 or the flexible substrate 227 alone, or the tube 241 may be attached to both the flexible barrier 213 and the flexible substrate 227. The reduced-pressure delivery tube 241 includes a distal port 243 at the distal end of the tube 241. The tube 241 may be positioned such that the distal port 243 is located at any point along the arcuate passage 223, but the tube 241 is preferably positioned such that the distal port 243 is located approximately midway along the longitudinal length of the arcuate passage 223. Distal port 243 is preferably elliptical or oval in shape by cutting tube 241 along a plane oriented less than 90 degrees from the longitudinal axis of tube 241. Although the ports 243 may also be circular, the elliptical shape of the ports 243 increases fluid communication with the flow channels 233 formed between the projections 231.

The reduced pressure delivery tube 241 is preferably made of silicone or urethane coated with paralyne. However, any medical grade tubular material may be used to construct the reduced-pressure delivery tube 241. Other coatings that may be applied to the tube include heparin, anticoagulants, anti-fibrinogen (anti-fibrinogen), anti-adhesion agents, anti-prothrombin (anti-thrombonogen), and hydrophilic coatings.

In one embodiment, the reduced-pressure delivery tube 241 may also include vent opening or vent 251 disposed along the reduced-pressure delivery tube 241 as an alternative to or in addition to the distal port 243 to further increase fluid communication between the reduced-pressure delivery tube 241 and the flow channel 233. As shown in fig. 1-5, the reduced-pressure delivery tube 241 may be disposed along only a portion of the longitudinal length of the arcuate channel 223, or alternatively may be disposed along the entire longitudinal length of the arcuate channel 223. If provided such that the reduced-pressure delivery tube 241 occupies the entire length of the arcuate passage 223, the distal orifice 243 may be covered such that all fluid communication between the tube 241 and the flow passage 233 is accomplished through the vent opening 251.

The reduced-pressure delivery tube 241 further includes a proximal port 255 at the proximal end of the tube 241. The proximal port 255 is configured to mate with a reduced-pressure source, which is described in more detail below with reference to fig. 9. The reduced-pressure delivery tube 241 is shown in fig. 1-3, 4A, and 5 and includes only a single lumen or passageway 259. However, the reduced-pressure delivery tube 241 may include multiple lumens, such as the dual lumen tube 261 shown in fig. 4B. The dual lumen tube 261 includes a first lumen 263 and a second lumen 265. The use of a dual lumen tube provides separate paths of fluid communication between the proximal end of the reduced-pressure delivery tube 241 and the flow channel 233. For example, the use of the dual lumen tube 261 may be used to allow communication between a reduced pressure source and the flow channel 233 along the first lumen 263. The second cavity 265 may be used to direct fluid to the flow channel 233. The fluid is filtered air or other gas, an antibacterial agent, an antiviral agent, a cell growth promoting agent, a rinse, a chemically active liquid, or any other fluid. If it is desired to direct multiple fluids to the flow channels 233 through separate fluid communication paths, the reduced-pressure delivery tube may be provided with more than two lumens.

Still referring to fig. 4B, a horizontal partition 271 separates the first and second chambers 263, 265 of the reduced-pressure delivery tube 261, resulting in the first chamber 263 being disposed above the second chamber 265. The relative positions of the first and second chambers 263, 265 may vary depending on how fluid communication is provided between the chambers 263, 265 and the flow channel 233. For example, a drain opening similar to drain opening 251 may be provided to allow communication with flow channel 233 when first chamber 263 is provided as described in FIG. 4B. When the second chamber 263 is configured as shown in fig. 4B, the second chamber 263 may communicate with the flow passage 233 through a distal port similar to the distal port 243. Alternatively, multiple lumens of the reduced-pressure delivery tube may be arranged side-by-side with vertical baffles separating the lumens, or the lumens may be arranged concentrically or coaxially.

It should be apparent to one of ordinary skill in the art that the provision of separate paths of fluid communication may be accomplished in a number of different ways, including the way in which a multi-lumen tube is provided as described above. Alternatively, separate paths of fluid communication may be provided by attaching a single lumen tube to another single lumen tube, or by using separate unattached tubes with a single lumen or multiple lumens.

If separate tubes are used to provide separate paths in fluid communication with the flow channel 233, the raised portion 215 may include a plurality of arcuate channels 223, one for each tube. Alternatively, the arcuate channel 223 may be enlarged to accommodate a plurality of tubes. An example of a reduced-pressure delivery apparatus having a reduced-pressure delivery tube separate from a fluid delivery tube is discussed in more detail below with reference to fig. 9.

Referring to fig. 6-8, a reduced pressure delivery apparatus or wing manifold 311 according to the principles of the present invention includes a flexible barrier 313 having a bulged portion 315 and a pair of wing portions 319. Each wing portion 319 is disposed along an opposite side of the spine portion 315. The raised portion 315 forms an arcuate channel 323 that may or may not extend the entire length of the wing manifold 311. Although the spine portion 315 may be centrally located on the wing manifold 311 such that the wing portions 319 are equally sized, the spine portion 315 may also be offset as shown in fig. 6-8, resulting in one wing portion 319 being wider than the other wing portion 319. The extra width of one wing section 319 may be particularly useful if the wing manifold 311 is used in conjunction with bone regeneration or healing, and the wider wing manifold 311 will wrap around a fixation member that is attached to the bone.

The cellular material 327 is attached to the flexible barrier 313 and may be provided as a single piece of material covering the entire surface of the flexible barrier 313, extending across the spine portion 315 and the two wing portions 319. The cellular material 327 includes an attachment surface (not visible in fig. 6) disposed adjacent to the flexible barrier 313, a primary distribution surface 329 opposite the attachment surface, and a plurality of perimeter surfaces 330.

In one embodiment, the flexible barrier 313 may be similar to the flexible barrier 213 and include a flexible backing. While adhesive is the preferred method of attaching the cellular material 327 to the flexible barrier 313, the flexible barrier 313 and cellular material 327 may be attached by any suitable attachment method or left to the user for assembly at the site of treatment. The flexible barrier 313 and/or flexible substrate act as an impermeable barrier to the transmission of fluids, such as liquids, air, and other gases.

In one embodiment, the flexible barrier and the flexible substrate may not be separately provided to support the cellular material 327. Rather, the cellular material 327 may have an integral barrier layer that is a non-permeable portion of the cellular material 327. Instead of a flexible barrier 313, the barrier layer may be formed of a closed cell material to prevent the transmission of fluids. If an integral barrier layer is formed for the cellular material 327, the barrier layer may include raised portions and wing portions, as previously described with reference to the flexible barrier 313.

The flexible barrier 313 is preferably made of an elastomeric material such as a silicone polymer. Examples of suitable siloxane polymers include MED-6015 manufactured by Nusil Technologies of Carpinteria, California. It should be noted, however, that the flexible barrier 313 may be made of any other biocompatible, flexible material. If the flexible barrier encases or otherwise incorporates a flexible substrate, the flexible substrate is preferably made of a polyester knit fabric, such as Bard6013 manufactured by c.r. Bard of Tempe, Arizona. However, the flexible substrate 227 may be made of any biocompatible flexible material that can increase the strength and durability of the flexible barrier 313.

In one embodiment, the cellular material 327 is an open cell reticulated polyether urethane (polyurethane) foam having a cell size ranging from about 400-600 microns. Examples of such foams may include GranuFoam manufactured by Kinetic Concepts, inc. The cellular material 327 may also be gauze, a felted mat (felted mat), or any other biocompatible material that provides fluid communication through multiple channels in three dimensions.

The cellular material 327 is primarily an "open cell" material that includes a plurality of cells fluidly connected to adjacent cells. A plurality of flow channels are formed by and between the "openings" of the cellular material 327. The flow channels provide fluid communication throughout the portion of the cellular material 327 having the openings. The apertures and flow channels may be uniform in shape and size, or may include patterned or random variations in shape and size. Variations in the shape and size of the pores of the cellular material 327 result in variations in the flow path, and such characteristics may be used to alter the flow characteristics of the fluid through the cellular material 327. The cellular material 327 may further include portions that include "closed cells". These closed cell portions of the cellular material 327 comprise a plurality of cells, most of which are not fluidly connected to adjacent cells. Examples of the closure portions are described above as barrier layers that can replace the flexible barrier 313. Similarly, the closed cell portions can be selectively disposed in the cellular material 327 to prevent fluid transmission through the perimeter surface 330 of the cellular material 327.

The flexible barrier 313 and the cellular material 327 may also be constructed of bioresorbable materials that do not have to be removed from the patient's body after use of the reduced pressure delivery apparatus 311. Suitable bioresorbable materials may include, without limitation, a polymeric blend of polylactic acid (PLA) and polyglycolic acid (PGA). The polymerization mixture may also include, without limitation, polycarbonate, polypropylene fumarate, and caprolactone. The flexible barrier 313 and the microporous material 327 may further serve as a scaffold for new cell growth, or a scaffold material may be used in conjunction with the flexible barrier 313, the flexible substrate 327, and/or the microporous material 327 to promote cell growth. Suitable scaffold materials may include, without limitation, calcium phosphate, collagen, PLA/PGA, coral hydroxyapatite, carbonate, or a treated allogeneic graft. Preferably, the scaffold material has a high porosity (i.e., high air content).

A reduced pressure delivery tube 341 is disposed within the arcuate channel 323 and is attached to the flexible barrier 313. The reduced-pressure delivery tube 341 may also be attached to the cellular material 327, or in the case where only the cellular material 327 is present, the reduced-pressure delivery tube 341 may be attached only to the cellular material 327. The reduced-pressure delivery tube 341 includes a distal port 343 at the distal end of the tube 341, which is similar to the distal port 243 of fig. 5. The reduced-pressure delivery tube 341 may be positioned such that the distal orifice 343 is located at any point along the arcuate channel 323, but is preferably located approximately midway along the longitudinal length of the arcuate channel 323. The distal orifice 343 is preferably made elliptical or oval in shape by cutting the tube 341 along a plane oriented less than 90 degrees from the longitudinal axis of the tube 341. Although the ports may also be circular, the elliptical shape of the ports increases fluid communication with the flow channels in the cellular material 327.

In one embodiment, the reduced-pressure delivery tube 341 may also include a vent opening or vent (not shown), similar to the vent opening 251 of fig. 5. A vent opening is provided along the tube 341 as an alternative to the distal port 343 or in addition to the distal port 343 to further increase fluid communication between the reduced-pressure delivery tube 341 and the flow passage. As previously described, the reduced-pressure delivery tube 341 may be disposed along only a portion of the longitudinal length of the arcuate channel 323, or alternatively may be disposed along the entire longitudinal length of the arcuate channel 323. If provided such that the reduced-pressure delivery tube 341 occupies the entire arcuate passage 323, the distal orifice 343 may be covered such that all fluid communication between the tube 341 and the flow passage is achieved through the discharge opening.

Preferably, the cellular material 327 covers and directly contacts the reduced-pressure delivery tube 341. The cellular material 327 may be connected to the reduced-pressure delivery tube 341, or the cellular material 327 may simply be attached to the flexible barrier 313. If the reduced-pressure delivery tube 341 is positioned such that it extends only to the midpoint of the arcuate channel 323, the cellular material 327 may also be connected to the bulged section 315 of the flexible barrier 313 in that region of the arcuate channel 323 that does not include the reduced-pressure delivery tube 341.

The reduced-pressure delivery tube 341 further includes a proximal port 355 at the proximal end of the tube 341. The proximal port 355 is configured to mate with a reduced-pressure source, which is described in more detail below with reference to fig. 9. The reduced-pressure delivery tube 341 shown in fig. 6-8 includes only a single chamber or passageway 359. However, the reduced-pressure delivery tube 341 may include multiple lumens, such as the multiple lumens described above with reference to fig. 4B. The use of a multi-lumen tube provides separate paths of fluid communication between the proximal end of the reduced-pressure delivery tube 341 and the flow channels, as previously described. These separate paths of fluid communication may also be provided by separate tubes having a single lumen or multiple lumens in communication with the flow channel.

Referring to fig. 8A and 8B, a reduced-pressure delivery apparatus 371 in accordance with the principles of the present invention includes a reduced-pressure delivery tube 373, the reduced-pressure delivery tube 373 having an extension portion 375 at a distal end 377 of the reduced-pressure delivery tube 373. The extension portion 375 is preferably shaped as an arch to match the curvature of the reduced-pressure delivery tube 373. The extension portion 375 may be formed by removing a portion of the reduced-pressure delivery tube 373 at the distal end 377, thereby forming a cutout 381 having a shoulder 383. A plurality of projections 385 are disposed on the inner surface 387 of the reduced pressure delivery tube 373 to form a plurality of flow channels 391 between the projections 385. The projections 385 may be similar in size, shape, and spacing to the projections described with reference to fig. 1-5. The reduced pressure delivery apparatus 371 is particularly adapted to apply reduced pressure to and regenerate tissue above connective tissue that can be received within incision 381. Ligaments, tendons, and cartilage are non-limiting examples of tissues that may be treated by the reduced pressure delivery apparatus 371.

Referring to fig. 9, a reduced pressure delivery apparatus 411, similar to other reduced pressure delivery apparatuses described herein, is used to apply reduced pressure tissue treatment to a tissue site 413, such as a patient's human bone 415. When used to promote bone tissue growth, reduced pressure tissue treatment may increase the rate of healing associated with fractures, nonunions, voids, or other bone defects. It is further believed that reduced pressure tissue treatment may be used to improve the recovery from osteomyelitis. The treatment may further be used to increase local bone density in patients suffering from osteoporosis. Finally, reduced pressure tissue treatment can be used to accelerate and improve the osseointegration of orthopedic implants such as hip implants, knee implants and fixation devices.

Still referring to fig. 9, the reduced-pressure delivery apparatus 411 includes a reduced-pressure delivery tube 419 having a proximal end 421, the proximal end 421 being fluidly connected to a reduced-pressure source 427. The reduced-pressure source 427 is a pump or any other device capable of applying a reduced pressure to the tissue site 413 through the reduced-pressure delivery tube 419 and the various flow paths associated with the reduced-pressure delivery device 411. The application of reduced pressure to the tissue site 413 is accomplished by positioning the wing portion of the reduced pressure delivery apparatus 411 adjacent to the tissue site 413, which in this particular example includes wrapping the wing portion around a void defect 429 in the bone 415. The reduced pressure delivery apparatus 411 may be inserted surgically or percutaneously. When percutaneously inserted, the reduced-pressure delivery tube 419 is preferably inserted through a sterile insertion sheath that penetrates the patient's dermal tissue.

Application of reduced pressure tissue treatment generally produces granulation tissue in the area surrounding the tissue site 413. Granulation tissue is a common tissue that is typically formed prior to tissue repair in vivo. Under normal circumstances, granulation tissue may form in response to foreign objects or during wound healing. Granulation tissue generally serves as a scaffold for healthy replacement tissue and further results in the growth of some scar tissue. Granulation tissue is highly vascularized, and in the presence of reduced pressure, the increased growth and growth rate of the highly vascularized tissue will promote new tissue growth at the tissue site 413.

Still referring to fig. 9, a fluid delivery tube 431 may be fluidly connected at a distal end to the flow channel of the reduced pressure delivery apparatus 411. The fluid delivery tube 431 includes a proximal end 432 fluidly connected to a fluid delivery source 433. If the fluid delivered to the tissue site is air, the air is preferably filtered by a filter 434 capable of filtering at least as small as 0.22 μm of particles in order to purify and disinfect the air. Directing air to the tissue site 413 is important to facilitate good drainage of the tissue site 413, particularly when the tissue site 413 is located below the surface of the skin, thereby reducing or preventing occlusion of the reduced-pressure delivery tube 419. The fluid delivery tube 431 and fluid delivery source 433 may also be used to introduce other fluids to the tissue site 413, including without limitation, antibacterial agents, antiviral agents, cell growth promoters, irrigation fluids, or other chemically active agents. When percutaneously inserted, the fluid delivery tube 431 is preferably inserted through a sterile insertion sheath that penetrates the patient's dermal tissue.

Pressure sensor 435 is operably connected to fluid delivery tube 431 to indicate whether fluid delivery tube 431 is occluded by blood or other bodily fluid. The pressure sensor 435 is operatively connected to the fluid delivery source 433 to provide feedback to control the amount of fluid introduced to the tissue site 413. A check valve (not shown) is also operably connected near the distal end of the fluid delivery tube 431 to prevent blood or other bodily fluids from entering the fluid delivery tube 431.

The separate paths of fluid communication provided by reduced pressure delivery tube 419 and fluid delivery tube 431 may be accomplished in a number of different ways, including providing a single lumen, multi-lumen tube as previously described with reference to fig. 4B. One of ordinary skill in the art will recognize that if a multi-lumen tube is used, sensors, valves, and other components associated with the fluid delivery tube 431 may similarly be associated with a particular lumen within the reduced pressure delivery tube 419. Preferably, any lumen or tube in fluid communication with the tissue site is coated with an anticoagulant to prevent occlusion of body fluids or blood in the lumen or tube. Other coatings that may coat the lumen or tube include, without limitation, heparin, anticoagulant, anti-fibrinogen, anti-adhesion, antithrombin, and hydrophilic coatings.

Referring to figures 10-19, experiments show the positive effect of reduced pressure tissue treatment when applied to bone tissue. In a particular test, reduced pressure tissue treatment was applied to the cranium of several rabbits to determine the effect on bone growth and regeneration, and the specific objectives of the test were to find the effect of reduced pressure tissue treatment on rabbits having no defect or damage on the cranium, the effect of reduced pressure tissue treatment on rabbits having critical-size defects on the cranium, and the effect of using scaffold material to treat critical-size defects on the cranium by reduced pressure tissue treatment. Specific test protocols and rabbit numbers are listed below in table 1.

Table 1: test protocol

A critical size defect is a defect in tissue (e.g., skull) that is of a size large enough that the defect cannot be completely healed by in vivo recovery. For rabbits, a full-thickness hole through the skull, approximately 15mm in diameter, is drilled, creating a critical-size defect of the skull.

Referring more particularly to fig. 10, a tissue section of a rabbit skull with untested, undamaged bone is shown. The bone tissue of the skull stained magenta, the surrounding soft tissue white, and the periosteum layer highlighted by a yellow asterisk. In fig. 11, a rabbit skull is shown after 6 days of application of reduced pressure tissue treatment and immediately thereafter, tissue harvesting. Bone and periosteum are visible and a layer of granulation tissue has formed. In fig. 12, a rabbit skull is shown after 6 days of application of reduced pressure tissue treatment and immediately following tissue harvesting. The tissue section of fig. 12 features the formation of new bone tissue under granulation tissue. Bone tissue is highlighted by a yellow asterisk. In fig. 13, a rabbit skull is shown after 6 days of application of reduced pressure tissue treatment and immediately following tissue harvesting. New bone and periosteum are visible. This histological manifestation of bone tissue formation in response to reduced pressure tissue treatment is very similar to that of bone formation in very young animals undergoing very rapid growth and deposition of new bone.

Referring more particularly to fig. 14-19, photographs and tissue slices showing the procedure and results of reduced pressure tissue treatment of rabbit cranium with critical size defects are shown. In fig. 14, a rabbit skull is shown with two critical size defects created. The through-thickness critical dimension defect is approximately 15mm in diameter. In fig. 15, a stainless steel mesh is placed over one critical dimension defect and a calcium phosphate stent is placed within a second critical dimension defect. In fig. 16, a reduced pressure tissue treatment device similar to those described herein is used to apply a reduced pressure to a critical-size defect. The amount of pressure applied to each defect was-125 mm Hg gauge pressure. According to one of the solutions listed in fig. 1, a reduced pressure is applied. In fig. 17, tissue sections of the skull after 6 days of reduced pressure tissue treatment and 12 weeks post-operative acquisition are shown. The sections shown include calcium phosphate scaffolds indicated by red arrows. The application of reduced pressure tissue treatment resulted in significant growth of new bone tissue, which is highlighted in figure 17 with a yellow asterisk. The amount of bone growth is significantly greater than the critical-size defect comprising the same calcium phosphate scaffold but not treated with reduced pressure tissue treatment. This observation suggests that there may be a threshold level or duration of treatment needed to obtain an abundance of new bone response. The effect of reduced pressure tissue treatment was most evident in the samples collected 12 weeks post-surgery, indicating that reduced pressure tissue treatment initiated a cascade of biological events that resulted in enhanced formation of new bone tissue.

The critical size defect covered with stainless steel mesh (fig. 15) but without scaffold material in the defect served as an in-animal controller with minimal new bone growth. These data highlight the advantages of appropriate scaffold materials and the positive effects of reduced pressure tissue treatment on scaffold integration and biological performance. In fig. 18 and 19, radiographs of a stent-filled critical dimension defect after six days of reduced pressure tissue treatment are shown. Figure 18 shows the defect 2 weeks post-surgery and shows some new bone deposition within the scaffold. The main structure of the stent is still evident. Fig. 19 shows the defect at 12 weeks post-surgery and shows that the critical dimension defect is nearly completely healed and the primary scaffold structure is nearly completely lost due to tissue integration, i.e., new bone formation within the scaffold matrix.

Referring to fig. 20, a reduced pressure delivery system 711 according to an embodiment of the present invention delivers reduced pressure tissue treatment to a tissue site 713 of a patient. The reduced pressure delivery system 711 includes a manifold delivery tube 721. Manifold delivery tube 721 may be a catheter or cannula and may include components such as a steering unit 725 and a guide wire 727 that allow manifold delivery tube 721 to be guided to tissue site 713. The placement and guidance of the guide wire 727 and manifold delivery tube 721 may be accomplished using endoscopy, ultrasound, fluoroscopy, auscultation, palpation, or any other suitable positioning technique. The manifold delivery tube 721 is configured to percutaneously insert the reduced pressure delivery apparatus to the tissue site 713 of the patient. When percutaneously inserted, the manifold delivery tube 721 is preferably inserted through a sterile insertion sheath that penetrates the patient's dermal tissue.

In fig. 20, tissue site 713 includes bone tissue adjacent to a fracture 731 on a patient's bone 733. The manifold delivery tube 721 is inserted through the patient's skin 735 and any soft tissue 739 surrounding the bone 733. As previously discussed, tissue site 713 may also include any other type of tissue including, without limitation, adipose tissue, muscle tissue, neural tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendons, or ligaments.

Referring to fig. 21 and 22, the reduced pressure delivery system 711 is further shown. The manifold delivery tube 721 may include a tapered distal end 743 for ease of insertion through the patient's skin 735 and soft tissue 739. The tapered distal end 743 may be further configured to flex radially outward to an open position such that the inner diameter of the distal end 743 is substantially equal to or greater than the inner diameter of the remainder of the tube 721. The open position of distal end 743 is schematically illustrated in fig. 21 by dashed line 737.

The manifold delivery tube 721 further includes a passageway 751, the passageway 751 including a reduced pressure delivery device 761 or any other reduced pressure delivery device. The reduced pressure delivery apparatus 761 includes a flexible barrier 765 and/or a microporous material 767 similar to those described with reference to fig. 6-8. The flexible barrier 765 and/or microporous material 767 are preferably wrapped, folded, or otherwise compressed around the reduced-pressure delivery tube 769 to reduce the cross-sectional area of the reduced-pressure delivery apparatus 761 within the channel 751.

After the distal end 743 of the manifold delivery tube 721 is placed at the tissue site 713, the reduced pressure delivery device 761 may be placed within the pathway 751 and directed to the tissue site 713. Alternatively, the reduced pressure delivery apparatus 761 may be pre-positioned within the passageway 751 prior to insertion of the manifold delivery tube 721 into the patient. If the reduced pressure delivery device 761 is pushed through the passageway 751, a biocompatible lubricant may be used to reduce friction between the reduced pressure delivery device 761 and the manifold delivery tube 721. When the distal end 743 is placed at the tissue site 713 and the reduced pressure delivery device 761 is delivered to the distal end 743, the reduced pressure delivery device 761 is then urged toward the distal end 743, causing the distal end 743 to expand radially outward into the open position. The reduced pressure delivery assembly 761 is pushed out of the manifold delivery tube 721, preferably into a void or space adjacent the tissue site 713. The void or space is typically formed by the dissection of soft tissue, which may be accomplished by percutaneous means. In some cases, tissue site 713 may be located at a wound site, and the void may occur naturally due to the anatomy of the wound. In other examples, the voids may be created by balloon ablation, sharp ablation, blunt ablation, water ablation (hydro ablation), pneumatic ablation, ultrasonic ablation, electrocautery ablation (electrocautery ablation), laser ablation, or any other suitable ablation technique. As the reduced pressure delivery apparatus 761 enters the void adjacent the tissue site 713, the flexible barrier 765 and/or the microporous material 767 of the reduced pressure delivery apparatus 761 unfold, expand, or decompress (see fig. 22) so that the reduced pressure delivery apparatus 761 can be placed in contact with the tissue site 713. Although not required, the flexible barrier 765 and/or the microporous material 767 may be subjected to a vacuum or reduced pressure provided by a reduced pressure delivery tube 769 to compress the flexible barrier 765 and/or the microporous material 767. Deployment of the flexible barrier 765 and/or the microporous material 767 can be accomplished by relieving the reduced pressure provided via the reduced-pressure delivery tube 769, or by providing positive pressure via the reduced-pressure delivery tube 769 to assist the deployment process. Final placement and manipulation of the reduced pressure delivery device 761 may be accomplished using endoscopy, ultrasound, fluoroscopy, auscultation, palpation, or any other suitable positioning technique. After placement of the reduced pressure delivery apparatus 761, the manifold delivery tube 721 is preferably removed from the patient, but the reduced pressure delivery tube associated with the reduced pressure delivery apparatus 761 remains in place to allow reduced pressure to be percutaneously applied to the tissue site 713.

Referring to fig. 23-25, a reduced pressure delivery system 811 according to an embodiment of the invention includes a manifold delivery tube 821 having a tapered distal end 843, the tapered distal end 821 configured to bend radially outward to an open position such that the inner diameter of the distal end 843 is substantially equal to or greater than the inner diameter of other portions of the tube 821. The open position of the distal end 843 is schematically illustrated in fig. 23-25 by dashed line 837.

The manifold delivery pipe 821 further includes a passage including a reduced pressure delivery device 861 therein, similar to any other reduced pressure delivery device described herein. The reduced pressure delivery apparatus 861 includes a flexible barrier 865 and/or a microporous material 867, the flexible barrier 865 and/or microporous material 867 preferably being wrapped, folded, or otherwise compressed around the reduced pressure delivery tube 869 to reduce the cross-sectional area of the reduced pressure delivery apparatus 861 within the pathway.

An impermeable membrane 871 having an interior space 873 is disposed about the reduced pressure delivery device 861 such that the reduced pressure delivery device 861 is contained within the interior space 873 of the impermeable membrane 871. The impermeable membrane 871 can be a balloon, sheath, or any other type of membrane capable of preventing fluid permeation such that the impermeable membrane 871 can assume at least one of a compressed position (see fig. 23), a relaxed position (see fig. 24), and an expanded position (see fig. 25 and 25A). Impermeable membrane 871 is sealably attached to manifold delivery tube 821 such that interior space 873 of impermeable membrane 871 is in fluid communication with the passageway of manifold delivery tube 821. Impermeable membrane 871 can optionally be attached to reduced pressure delivery tube 869 such that interior space 873 of impermeable membrane 871 is in fluid communication with the passageways of reduced pressure delivery tube 869. Impermeable membrane 871 can alternatively be attached to a separate control tube or control lumen in fluid communication with interior space 873 (see, e.g., fig. 25A).

In one embodiment, the impermeable membrane 871 can be configured to further reduce the cross-sectional area of the reduced pressure delivery apparatus 861 within the pathway. To accomplish this, the pressure applied to interior space 873 of impermeable membrane 871 is less than the ambient pressure surrounding impermeable membrane 871. A substantial portion of the air or other fluid within interior space 873 is thus evacuated, placing impermeable membrane 871 in the compressed position shown in fig. 23. In the compressed position, the impermeable membrane 871 is pulled inward to apply a compressive force to the reduced pressure delivery device 861 to further reduce the cross-sectional area of the reduced pressure delivery device 861. After the distal end 843 of the manifold delivery tube 821 is placed at the tissue site, the reduced pressure delivery device 861 may be delivered to the tissue site, as previously described with reference to figures 21 and 22. The placement and operation of reduced pressure delivery device 861 and impermeable membrane 871 may be accomplished using endoscopy, ultrasound, fluoroscopy, auscultation, palpation, or any other suitable positioning technique. The impermeable membrane 871 can include a radio-opaque marker 881, which can enhance visualization under fluoroscopy prior to removal of the impermeable membrane 871.

After pushing the reduced pressure delivery device 861 through the distal end 843, the reduced pressure applied to the interior space 873 may be attenuated to place the impermeable membrane 871 in a relaxed position (see fig. 24), thereby facilitating easier removal of the reduced pressure delivery device 861 from the impermeable membrane 871. A removal tool 885, such as a trocar, stylet, or other sharp instrument, may be provided to rupture the impermeable membrane 871. Preferably, removal tool 885 is inserted through reduced-pressure delivery tube 869 and can be advanced into contact with impermeable membrane 871. After severing the impermeable membrane 871, the removal tool 885 and the impermeable membrane 871 may be retracted through the manifold delivery tube 821, allowing the flexible barrier 865 and/or the microporous material 867 of the reduced pressure delivery device 861 to expand, splay, or decompress so that the reduced pressure delivery device 861 may be placed in contact with the tissue site. Deployment of the flexible barrier 865 and/or the microporous material 867 may occur automatically upon relaxation of the reduced pressure communicated to the interior space 873 and removal of the impermeable membrane 871. In some cases, a positive pressure may be transmitted through the reduced-pressure transmission tube 869 to help deploy or decompress the flexible barrier 865 and/or the microporous material 867. After final placement of the reduced pressure delivery apparatus 861, the manifold delivery tube 821 is preferably removed from the patient, but the reduced pressure delivery tube 869 associated with the reduced pressure delivery apparatus 861 remains in place to allow reduced pressure to be percutaneously applied to the tissue site.

The impermeable membrane 871 can also be used to strip tissue adjacent to the tissue site prior to placing the reduced pressure delivery device 861 against the tissue site. After pushing the reduced pressure delivery device 861 and the intact impermeable membrane 871 through the distal end 843 of the manifold delivery tube 821, air or other fluid may be injected or drawn into the interior space 873 of the impermeable membrane 871. It is preferable to use a liquid to inflate impermeable membrane 871 because the incompressibility of the liquid allows impermeable membrane 871 to expand more uniformly and consistently. Impermeable membrane 871 may be radially expanded as shown in fig. 25 or directionally expanded depending on its method of manufacture and attachment to manifold delivery tube 821. As the impermeable membrane 871 expands outward into the expanded position due to the pressure of air or fluid (see fig. 25), the void adjacent the tissue site is peeled away. When the void is large enough, liquid, air, or other fluid may be released from inner space 873 to allow impermeable membrane 871 to assume a relaxed position. The impermeable membrane 871 can then be slit as previously explained and a reduced pressure delivery device 861 inserted adjacent to the tissue site.

Referring to fig. 25A, if impermeable membrane 871 is used primarily to dissect tissue adjacent a tissue site, impermeable membrane 871 may be sealingly attached to manifold delivery tube 821 such that interior space 873 is in fluid communication with a secondary lumen or tube 891 associated with or attached to manifold delivery tube 821. Secondary cavity 891 may be used to deliver liquid, air, or other fluid to interior space 873 to place impermeable membrane 871 in the expanded position. After peeling, impermeable membrane 871 can be relaxed and slit as previously described with reference to fig. 24.

Referring to fig. 26, a reduced pressure delivery system 911 according to an embodiment of the present invention includes a manifold delivery tube 921 having a tapered distal end 943, the tapered distal end 943 configured to flex radially outward to an open position such that the inner diameter of the distal end 943 is substantially equal to or greater than the inner diameter of the remainder of the tube 921. The open position of the distal end 943 is schematically illustrated in fig. 26 by dashed line 937.

The manifold delivery tube 921 further includes a passageway including a reduced pressure delivery apparatus 961, similar to other reduced pressure delivery apparatuses described herein. The reduced-pressure delivery apparatus 961 includes a flexible barrier 965 and/or a microporous material 967, the flexible barrier 965 and/or microporous material 967 preferably being rolled, folded, or otherwise compressed around the reduced-pressure delivery tube 969 to reduce the cross-sectional area of the reduced-pressure delivery apparatus 961 within the pathway of the manifold delivery tube 921.

An impermeable membrane 971 having an interior space 973 is disposed about the reduced pressure delivery apparatus 961 such that the reduced pressure delivery apparatus 961 is included within the interior space 973 of the impermeable membrane 971. The impermeable membrane 971 includes a glue seal 977 on one end of the impermeable membrane 971 to provide an alternative method of removing the reduced pressure delivery apparatus 961 from the impermeable membrane 971. The impermeable membrane 971 may be sealingly attached to the other end of the manifold delivery tube 921 such that the interior space 973 of the impermeable membrane 971 is in fluid communication with the passageways of the manifold delivery tube 921. Alternatively, the impermeable membrane 971 may be attached to a separate control tube (not shown) in fluid communication with the interior space 973.

Similar to the impermeable membrane 871 of fig. 23, the impermeable membrane 971 is capable of preventing fluid permeation such that the impermeable membrane 971 can assume at least one of a compressed position, a relaxed position, and an expanded position. Because the procedure for placing the impermeable membrane 971 in the compressed position and the expanded position is similar to that of the impermeable membrane 871, only the different processes of removing the reduced pressure delivery apparatus 961 are described.

The reduced pressure delivery apparatus 961 is delivered to the tissue site within the impermeable membrane 971 and then appropriately positioned using endoscopy, ultrasound, fluoroscopy, auscultation, palpation, or any other appropriate positioning technique. The impermeable membrane 971 may include a radio-opaque marker 981, which radio-opaque marker 981 may enhance visualization under fluoroscopy prior to removal of the impermeable membrane 971. The reduced pressure delivery apparatus 961 is then pushed through the distal end 943 of the manifold delivery tube 921. The reduced pressure applied to the interior space 973 may be reduced to place the impermeable membrane 971 in a relaxed position. The reduced-pressure delivery device 961 is then pushed through the glue seal 977 to exit the impermeable membrane 971.

Referring to fig. 26A, a reduced pressure delivery system 985 according to embodiments of the present invention may not include a manifold delivery tube similar to manifold delivery tube 921 of fig. 26. Alternatively, reduced pressure delivery system 985 may include guide wire 987, reduced pressure delivery tube 989, and reduced pressure delivery apparatus 991. The reduced-pressure delivery apparatus 991 includes a plurality of flow channels fluidly connected to a reduced-pressure delivery tube 989. Rather than using a separate manifold delivery tube to deliver reduced pressure delivery apparatus 991, reduced pressure delivery apparatus 991 and reduced pressure delivery tube 989 are disposed over a guide wire 987 that is percutaneously guided to tissue site 993. Preferably, the guide wire 987 and reduced pressure delivery tube 989 penetrate the patient's skin through a sterile sheath. By guiding the reduced-pressure delivery tube 989 and reduced-pressure delivery apparatus 991 along guide wire 987, the reduced-pressure delivery apparatus 991 may be placed at the tissue site 993 to allow percutaneous application of reduced-pressure tissue treatment.

Because the reduced-pressure delivery apparatus 991 is not confined within the manifold delivery tube during delivery to the tissue site 993, it is preferable to maintain the reduced-pressure delivery apparatus 991 in a compressed position during delivery. If a resilient foam is used as the reduced pressure delivery apparatus 991, a biocompatible, soluble adhesive may be applied to the foam and the compressed foam. Upon reaching the tissue site, the bodily fluids or other fluids delivered through the reduced-pressure delivery tube 989 dissolve the adhesive, allowing the foam to expand into contact with the tissue site. Alternatively, the reduced pressure delivery apparatus 991 may be formed from a compressed, dry hydrogel. The hydrogel absorbs moisture after delivery to the tissue site 993, allowing the reduced pressure delivery apparatus 991 to expand. Yet another reduced pressure delivery apparatus 991 may be made of a thermally active material (e.g., polyethylene glycol) that expands at the tissue site 993 when exposed to body heat of a patient. In yet another embodiment, the compressed reduced pressure delivery apparatus 991 may be delivered to the tissue site 993 in a dissolvable film.

Referring to fig. 27, a reduced pressure delivery system 1011 according to an embodiment of the present invention includes a manifold delivery tube 1021 having a distal end 1043, the distal end 1043 being inserted through tissue of a patient to access a tissue site 1025. Tissue site 1025 may include a void 1029 associated with a wound or other defect, or alternatively, a void may be created by dissection, including the dissection techniques described herein.

After distal end 1043 is placed within void 1029 adjacent tissue site 1025, injectable, pourable or flowable reduced pressure delivery device 1035 is delivered to tissue site 1025 through manifold delivery tube 1021. Preferably, reduced pressure delivery apparatus 1035 exists in a flowable state during delivery to the tissue site and then forms a plurality of flow channels for distributing the reduced pressure or fluid upon arrival. In some cases, after reaching the tissue site, the flowable substance may be hardened into a solid state by a drying process, a curing process, or other chemical or physical reaction. In other cases, the flowable substance may form a foam in situ after delivery to the tissue site. Other flowable substances in a gel-like state may also be present at tissue site 1025, but still have multiple flow channels for delivering reduced pressure. The number of reduced pressure delivery devices 1035 delivered to the tissue site 1025 may be sufficient to partially or completely fill the void 1029. Reduced pressure delivery apparatus 1035 may include both aspects of a manifold and a scaffold. As a manifold, reduced pressure delivery apparatus 1035 includes a plurality of small holes or apertures that may be formed in the material after delivery to void 1029. The orifices or openings communicate with each other to create a plurality of flow channels. The flow channel is used to apply and distribute reduced pressure to the tissue site 1025. As a scaffold, reduced pressure delivery device 1035 is bioresorbable and serves as a substrate upon which and within which new tissue may grow.

In one embodiment, reduced pressure delivery apparatus 1035 may include a porogen (poragen), such as NaCl, or other salts distributed throughout a liquid or viscous gel. After the liquid or viscous gel is delivered to the tissue site 1025, the materials conform to the void 1029 and then solidify into a solid state. Water soluble NaCl porogens dissolve in the presence of body fluids, leaving a structure or flow channel with interconnected pores. The reduced pressure and/or fluid is communicated to the flow channel. As new tissue grows, the tissue grows into the aperture of reduced pressure delivery apparatus 1035 and then eventually replaces it as reduced pressure delivery apparatus 1035 degrades. In this particular example, reduced pressure delivery apparatus 1035 not only serves as a manifold, but also as a scaffold for new tissue growth.

In another embodiment, reduced pressure delivery apparatus 1035 is alginate mixed with 400 μm mannose beads (beads). The porogen or bead may be dissolved by local body fluids or by irrigation fluids or other fluids delivered to reduced pressure delivery means 1035 at the tissue site. After the porogen or bead dissolves, the space previously occupied by the porogen or bead becomes a void that interconnects with other voids to form a flow channel within reduced pressure delivery means 1035.

The use of porogens to create flow channels in a material is effective, but it also forms small pores and flow channels that are limited in size to about the particle size of the selected porogen. Instead of porogens, chemical reactions can be used to create larger pores due to the formation of gaseous by-products. For example, in one embodiment, a flowable substance may be delivered to the tissue site 1025 that includes sodium bicarbonate and citric acid microparticles (non-stoichiometric amounts may be used). When the flowable substance forms a foam or solid in situ, the body fluid will cause an acid-base reaction between the sodium bicarbonate and the citric acid. The resulting carbon dioxide gas particles produced produce larger pores and flow channels throughout reduced pressure delivery apparatus 1035 than techniques that rely on porogen dissolution.

The transition of reduced pressure delivery means 1035 from a liquid or viscous gel to a solid or foam may be triggered by pH, temperature, light, or reaction with body fluids, chemicals or other substances delivered to the tissue site. The conversion may also occur by mixing a plurality of reaction components. In one embodiment, reduced pressure delivery apparatus 1035 is prepared by selecting bioresorbable microspheres made from any bioresorbable polymer. The microspheres are dispersed in a solution comprising a photoinitiator and a hydrogel-forming material, such as hyaluronic acid, collagen or polyethylene glycol having photoreactive groups. The microsphere-gel mixture is exposed to light for a brief period of time to partially crosslink the hydrogel and immobilize the hydrogel on the microspheres. Additional solution is drained and the microspheres are then dried. The microspheres are delivered to the tissue site by injection or perfusion, and after delivery, the mixture absorbs moisture and the hydrogel coating becomes hydrated. The mixture is then re-exposed to light which crosslinks the microspheres, thereby creating a plurality of flow channels. The crosslinked microspheres then act as a scaffold to transmit reduced pressure to the tissue site and as a porous scaffold to promote new tissue growth.

In addition to the previous embodiments described herein, the reduced pressure delivery apparatus 1035 may be made from a variety of materials, including without limitation calcium phosphate, collagen, alginate, cellulose, or any other equivalent material capable of being delivered to a tissue site as a gas, liquid, gel, paste, putty, slurry, suspension, or other flowable substance, and capable of forming multiple flow paths in fluid communication with the tissue site. The flowable substance may further comprise particulate solids, such as beads, which are capable of flowing through the manifold delivery tube 1021 if the particulate solids are sufficiently small in size. The substance delivered to the tissue site in a flowable state may polymerize or gel in situ.

As previously described, reduced pressure delivery apparatus 1035 may be injected or infused directly into void 1029 adjacent tissue site 1025. Referring to fig. 27A, the manifold delivery tube 1021 may include an impermeable membrane or a semi-permeable membrane 1051 at a distal end 1043 of the manifold delivery tube 1021. The membrane 1051 includes an interior space 1055, the interior space 1055 being in fluid communication with a secondary lumen 1057 attached to a manifold delivery tube 1021. The manifold delivery tube 1021 is directed to a tissue site 1025 over a guide wire 1061.

The reduced-pressure delivery device 1035 may be injected or poured through the secondary cavity 1057 to fill the interior space 1055 of the membrane 1051. When the fluid or gel fills membrane 1051, membrane 1051 expands to fill void 1029, bringing the membrane into contact with tissue site 1025. When film 1051 is expanded, film 1051 can be used to dissect additional tissue adjacent or proximal to tissue site 1025. The film 1051, if impermeable, may be physically slit and removed, leaving the reduced-pressure delivery device 1035 in contact with the tissue site 1025. Alternatively, the membrane 1051 may be made of a soluble material that dissolves when in the presence of a body fluid or biocompatible solvent that can be transferred to the membrane 1051. If the membrane 1051 is semi-permeable, the membrane 1051 may remain in place. The semi-permeable membrane 1051 allows for reduced pressure and possibly other fluids to be delivered to the tissue site 1025.

Referring to fig. 28, a method 1111 of applying reduced pressure tissue treatment to a tissue site includes surgically inserting a manifold adjacent the tissue site, the manifold having a plurality of projections extending from a flexible barrier to create flow channels between the projections at 1115. At 1119, the manifold is placed such that at least a portion of the projections are in contact with the tissue site. At 1123, a reduced pressure is applied to the tissue site through the manifold.

Referring to fig. 29, a method 1211 of applying reduced pressure tissue treatment to a tissue site includes percutaneously inserting a manifold adjacent the tissue site 1215. The manifold may include a plurality of projections extending from the flexible barrier to create flow channels between the projections. Alternatively, the manifold may comprise a microporous material having a plurality of flow channels therein. Alternatively, the manifold may be formed of an injectable or perfusable material that is delivered to the tissue site and forms a plurality of flow channels upon reaching the tissue site. At 1219, the manifold is placed such that at least a portion of the flow channel is in fluid communication with the tissue site. At 1223, reduced pressure is applied to the tissue site through the manifold.

Referring to figure 30, a method 1311 of applying reduced pressure tissue treatment to a tissue site includes percutaneously inserting a tube having a passageway through tissue of a patient to position a distal end of the tube adjacent to the tissue site at 1315. At 1319, a balloon associated with the tube is inflated to dissect tissue adjacent the tissue site, thereby creating a void. At 1323, a manifold is delivered through the passageway. The manifold may include a plurality of projections extending from the flexible barrier to create flow channels between the projections. Alternatively, the manifold may comprise a microporous material having a plurality of flow channels therein. Alternatively, the manifold may be formed from an injectable or perfusable substance that is delivered to the tissue site, as previously described with reference to fig. 27. At 1327, the manifold is placed within the void such that at least a portion of the flow channel is in fluid communication with the tissue site. At 1331, the reduced pressure is applied to the tissue site through the manifold via a reduced pressure delivery tube or any other delivery device.

Referring to fig. 31, a method 1411 of applying reduced pressure tissue treatment to a tissue site includes percutaneously inserting a tube having a passageway through tissue of a patient to position a distal end of the tube adjacent to the tissue site at 1415. The manifold is delivered to the tissue site through the passageway within the impermeable sheath at 1423, and the impermeable sheath is subjected to a first reduced pressure that is less than the ambient pressure of the sheath at 1419. At 1427, the sheath is split to place the manifold in contact with the tissue site. At 1431, a second reduced pressure is applied to the tissue site through the manifold.

Referring to fig. 32 and 33, a reduced pressure delivery apparatus 1511 according to an embodiment of the present invention includes an orthopaedic hip prosthesis 1515 for replacing an existing femoral head of a patient's femur 1517. The hip prosthesis 1515 includes a stem portion 1521 and a head portion 1525. The stem portion 1521 is elongated for insertion within the channel 1529, the channel 1529 being enlarged in the stem of the femur 1517. Porous coating 1535 is disposed around the stem portion and is preferably composed of a sintered or vitrified ceramic or metal. Alternatively, a microporous material having porous characteristics may be disposed around the stem portion. A plurality of flow channels 1541 are disposed within the stem portion 1521 of the hip prosthesis 1515 such that the flow channels 1541 are in fluid communication with the porous coating 1535. A connection port 1545 is fluidly connected to the flow channel 1541, the port configured to releasably connect to a reduced-pressure delivery tube 1551 and a reduced-pressure delivery source 1553. Flow channels 1541 are used to deliver reduced pressure to porous coating 1553 and/or the bone surrounding hip prosthesis 1515 after implantation. The flow channel 1541 may include a main supply line 1543 in fluid communication with a number of side branches 1547, the side branches 1547 being in communication with the porous coating 1535. Side branch 1545 may be oriented perpendicular to main feeder 1543, as shown in fig. 32, or may be oriented at an angle to main feeder 1543. An alternative method for distributing the reduced pressure includes providing a hollow hip prosthesis, and filling the interior space of the prosthesis with a porous (preferably open-celled) material capable of being in fluid communication with the porous coating 1535.

Referring more particularly to fig. 33, hip prosthesis 1515 may further include a second plurality of flow channels 1561 within stem portion 1521 to provide fluid to porous coating 1535 and/or the bone surrounding hip prosthesis 1515. The fluid may include filtered air or other gases, antimicrobial agents, antiviral agents, cell growth promoters, irrigation fluids, chemically active fluids, or any other fluid. Additional paths of fluid communication may be provided if it is desired to direct multiple fluids to the bone surrounding the hip prosthesis 1515. The connection port 1565 is fluidly connected to the flow channel 1561, and the port 1565 is configured to releasably connect to a fluid delivery tube 1571 and a fluid delivery source 1573. The flow path 1561 may include a main supply line 1583 in fluid communication with a number of side branches 1585, the side branches 1585 being in communication with a porous coating 1535. The side branch 1585 may be oriented perpendicular to the main supply line 1583 as shown in figure 33 or may be oriented at an angle to the main supply line 1583.

The communication of the reduced pressure to the first plurality of flow channels 1541 and the communication of the fluid to the second plurality of flow channels 1561 may be accomplished by separate tubes, such as a reduced pressure communication tube 1551 and a fluid communication tube 1571. Alternatively, a tube having multiple lumens as previously described herein may be used to separate the communication paths for communicating the reduced pressure and fluid. It should be further noted that while a separate path providing fluid communication within hip prosthesis 1515 is preferred, the first plurality of flow channels 1541 may be used to deliver both reduced pressure and fluid to the bone surrounding hip prosthesis 1515.

As previously described, the application of reduced pressure to the bone tissue promotes and accelerates the growth of new bone tissue. By using the hip prosthesis 1515 as a scaffold to deliver reduced pressure to the area of bone surrounding the hip prosthesis, recovery of the femur 1517 is faster and the hip prosthesis 1515 is more successfully integrated with the bone. Providing a second plurality of flow channels 1561 to provide drainage openings to the bone surrounding hip prosthesis 1515 improves the successful creation of new bone around the prosthesis.

After a selected amount of time of applying reduced pressure through the hip prosthesis 1515, the reduced-pressure delivery tube 1551 and the fluid delivery tube 1571 may be disconnected from the connection ports 1545, 1565 and removed from the patient, preferably without a surgical invasive procedure. The connection between the connection ports 1545, 1565 and the tubes 1551, 1571 may be a manually releasable connection that is achieved by applying an axially facing tension to the tubes 1551, 1571 outside the patient's body. Optionally, the connection ports 1545, 1565 may be bioresorbable or dissolvable in the presence of a selected fluid or chemical, such that release of the tubes 1551, 1571 may be obtained by exposing the connection ports 1545, 1565 to the fluid or chemical. Tubes 1551, 1571 may also be made of bioresorbable materials that dissolve over a period of time or active materials that dissolve in the presence of a particular chemical or other substance.

A reduced pressure delivery source 1553 may be disposed outside the patient's body and connected to a reduced pressure delivery tube 1551 to deliver a reduced pressure to the hip prosthesis 1515. Alternatively, reduced pressure delivery source 1553 may be implanted on or near hip prosthesis 1515 (on-board) within the patient. The placement of the reduced-pressure delivery source 1553 within the patient's body eliminates the need for a percutaneous fluid connection. The implanted reduced-pressure delivery source 1553 may be a conventional pump operably connected to the flow passage 1541. The pump may be powered by a battery implanted in the patient, or may be powered by an external battery electrically and percutaneously connected to the pump. The pump may also be driven directly by a chemical reaction that delivers reduced pressure and circulates fluid through the flow channels 1541, 1561.

Although only the stem portion 1521 and the head portion 1525 of the hip prosthesis 1515 are shown in fig. 32 and 33, it should be noted that the flow channels and apparatus described herein for applying reduced pressure tissue treatment may be applied to any component of the hip prosthesis 1515 that contacts bone or other tissue, including, for example, an acetabular cup.

Referring to fig. 34, a method 1611 for repairing a joint of a patient includes, at 1615, implanting a prosthesis within bone adjacent to the joint. The prosthesis may be a hip prosthesis as described above, or any other prosthesis that helps restore mobility to a joint of a patient. The prosthesis includes a plurality of flow channels configured to be in fluid communication with the bone. At 1619, reduced pressure is applied to the bone through the plurality of flow channels to improve osseointegration of the prosthesis.

Referring to fig. 35 and 36, a reduced pressure delivery apparatus 1711 in accordance with an embodiment of the present invention includes an orthopedic fixation device 1715 for fixation of a patient's bone 1717 including a fracture 1719 or other defect. The orthopedic fixation device 1715 shown in fig. 35 and 36 is a plate having a plurality of channels 1721, the channels 1721 for anchoring the orthopedic fixation device 1715 to a bone 1717 with screws 1725, pins, bolts, or other fasteners. A porous coating 1753 may be disposed on the surface of the orthopedic fixation device 1715 that will be in contact with the bone 1717. The porous coating is preferably composed of a sintered or vitrified ceramic or metal. Alternatively, a microporous material having porous characteristics may be disposed between the bone 1717 and the orthopedic fixation device 1715. A plurality of flow channels 1741 is disposed within the orthopedic fixation device 1715 such that the flow channels 1741 are in fluid communication with the porous coating 1735. A connection port 1745 is fluidly connected to the flow channel 1741, the port being configured to connect to a reduced pressure delivery tube 1751 and a reduced pressure delivery source 1753. The flow channel 1741 is used to transmit reduced pressure to the porous coating 1753 and/or the bone surrounding the orthopedic fixation device 1715 after the orthopedic fixation device 1715 is secured to the bone 1717. The flow passageway 1741 may include a main supply line 1743 in fluid communication with a number of side branches 1747, with the side branches 1747 in communication with the porous coating 1735. The side branch 1747 may be oriented perpendicular to the main feeding line 1743 as shown in fig. 35, or may be oriented at an angle to the main feeding line 1743. An alternative method for distributing the reduced pressure includes providing a hollow orthopedic fixation device and filling the interior space of the orthopedic fixation device with a porous (preferably open cell) material that is capable of fluid communication with the porous coating 1735.

The orthopedic fixation device 1715 can be a plate as shown in fig. 35, or alternatively can be a fixation device such as a sleeve, brace, strut, or any other device for stabilizing a portion of a bone. The orthopedic fixation device 1715 may further be a fastener for attaching a prosthetic device or other orthopedic device or transplanted tissue (e.g., bone tissue or cartilage), provided the fastener includes a flow channel for transmitting reduced pressure to the tissue adjacent to or surrounding the fastener. Examples of such fasteners may include pins, bolts, screws, or any other suitable fastener.

Referring more particularly to fig. 36, the orthopedic fixation device 1715 can further include a second plurality of flow channels 1761 within the orthopedic fixation device 1715 to provide fluid to the porous coating 1735 and/or the bone surrounding the orthopedic fixation device 1715. The fluid may include filtered air or other gases, antimicrobial agents, antiviral agents, cell growth promoters, irrigation fluids, chemically active fluids, or any other fluid. Additional paths of fluid communication may be provided if it is desired to direct multiple fluids to the bone surrounding the orthopedic fixation device 1715. A connection port 1765 is fluidly connected to the flow channel 1761, the port 1765 being configured to be connected to a fluid delivery tube 1771 and a fluid delivery source 1773. The flow channel 1761 may include a main supply line 1783 in fluid communication with a number of side branches 1785, the side branches 1785 being in communication with the porous coating 1735. The side branch 1785 may be oriented perpendicular to the main feeder line 1783, as shown in fig. 33, or may be oriented at an angle to the main feeder line 1783.

The transfer of reduced pressure to the first plurality of flow channels 1741 and the transfer of fluid to the second plurality of flow channels 1761 may be accomplished by separate tubes, such as a reduced pressure transfer tube 1751 and a fluid transfer tube 1771. Alternatively, a tube having multiple lumens as previously described herein may be used to separate the communication paths for communicating the reduced pressure and fluid. It should be further noted that while providing separate paths of fluid communication within the orthopedic fixation device 1715 is preferred, the first plurality of flow channels 1741 can be used to deliver both reduced pressure and fluid to the bone adjacent to the orthopedic fixation device 1715.

The use of orthopedic fixation device 1715 as a scaffold to transmit reduced pressure to the bone region adjacent orthopedic fixation device 1715 accelerates and improves the recovery of defect 1719 of bone 1717. Providing a second plurality of flow channels 1761 to deliver fluid to the bone surrounding the orthopedic fixation device 1715 enhances the successful creation of new bone in the vicinity of the orthopedic fixation device.

Referring to fig. 37, a method 1811 for healing a bone defect of a bone includes, at 1815, fixing the bone using an orthopedic fixation device. The orthopedic fixation device includes a plurality of flow channels disposed in the orthopedic fixation device. At 1819, reduced pressure is applied to the bone defect through the plurality of flow channels.

Referring to fig. 38, a method 1911 for administering reduced pressure tissue treatment to a tissue site includes placing 1915 a manifold having a plurality of flow channels such that at least a portion of the flow channels are in fluid communication with the tissue site. A reduced pressure is applied 1919 to the tissue site through the flow channel, and fluid is delivered 1923 to the tissue site through the flow channel.

Referring to fig. 39, a method 2015 for applying reduced pressure tissue treatment to a tissue site includes positioning a distal end of a manifold delivery tube 2015 adjacent to the tissue site. At 2019, fluid is delivered to the tissue site through the manifold delivery tube. The fluid is capable of filling a void adjacent to the tissue site and becomes a solid manifold having a plurality of flow channels in fluid communication with the tissue site. A reduced pressure is applied 2023 to the tissue site through the flow channel of the solid state manifold.

40-48, the reduced pressure delivery system 2111 includes a primary manifold 2115, the primary manifold 2115 having a flexible wall 2117 surrounding a primary flowpath 2121. The flexible wall 2117 is connected to a reduced-pressure delivery tube 2125 at a proximal end 2123. Because the shape of the reduced-pressure delivery tube 2125 is generally circular in cross-section, and because the shape of the primary manifold 2115 may not be circular in cross-section (i.e., rectangular in fig. 40-45 and triangular in fig. 46-48), a transition region 2129 may be provided between the reduced-pressure delivery tube 2125 and the primary manifold 2115. The primary manifold 2115 may be adhesively connected to the reduced-pressure delivery tube 2125, connected using other methods such as melt or insert molding (insert molding), or alternatively may be integrally connected by coextrusion. The reduced pressure delivery tube 2125 delivers a reduced pressure to the primary manifold 2115 for distribution at or near the tissue site.

A blockage prevention member 2135 is disposed within the primary manifold to prevent collapse of manifold 2115 and thus blockage of primary flow passage 2121 during application of reduced pressure. In one embodiment, the blockage prevention member 2135 can be a plurality of projections 2137 (see fig. 44), the projections 2137 being disposed on the inner surface 2141 of the flexible wall 2117 and extending into the primary flow passage 2121. In another embodiment, the blockage prevention member 2135 can be a single ridge or multiple ridges 2145 disposed on the inner surface 2141 (see fig. 40 and 41). In yet another embodiment, the blockage prevention member 2135 can include a cellular material 2149 disposed within the primary flow passage, such as shown in fig. 47. The blockage prevention member 2135 can be any material or structure that can be inserted within the flow passage or can be integral or otherwise attached to the flexible wall 2117. The blockage prevention member 2135 can prevent complete collapse of the flexible wall 2117 while still allowing fluid flow through the primary flow passage 2121.

The flexible wall 2117 further includes a plurality of apertures 2155 extending through the flexible wall 2117 in communication with the primary flow passage 2121. The apertures 2155 allow for a reduced pressure distribution to the primary flow passage 2121 to the tissue site. Apertures 2155 may be optionally provided around the perimeter of the manifold 2115 to preferentially direct the delivery of vacuum. For example, in fig. 51, the holes may be disposed facing the bone, facing the overlying tissue, or both.

The reduced-pressure delivery tube 2125 preferably includes a first conduit 2161 having at least one outlet fluidly connected to the primary flow passage 2121 to deliver a reduced pressure to the primary flow passage 2121. The second conduit 2163 may also be configured to wash the primary flow passage 2121 and the first conduit 2161 with a fluid to prevent or dissolve obstructions caused by wound exudate or other fluids emanating from the tissue site. The second conduit 2163 preferably includes at least one outlet disposed proximate to at least one primary flow passage 2121 and at least one outlet of the first conduit 2161.

Referring more particularly to fig. 40 and 41, the second conduit 2163 of the reduced pressure delivery system 2111 may include a plurality of conduits for cleaning the primary flow passage 2121 and the first conduit 2161. While the end of the flexible wall 2117 opposite the end attached to the reduced pressure delivery tube 2125 may be open, as shown in fig. 40, it has been found that covering the end of the flexible wall 2117 may improve the performance and reliability of the cleaning function. Preferably, a head space 2171 is provided between the covered end of the flexible wall and the end of the second conduit 2163. The head space 2171 allows for an enhancement of the cleaning fluid during the cleaning process, which helps to drive the cleaning fluid through the primary flow passage 2121 and into the first conduit 2161.

Also shown in fig. 41 is a spacer that acts as an occlusion prevention member 2135. The centrally located divider divides primary flow passage 2121 into two chambers, which allows for continued operation of primary manifold 2115 if one chamber becomes blocked and the wash cannot dissolve the blockage.

Referring to fig. 49 and 50, the reduced-pressure delivery system 2211 includes a primary manifold 2215 that is integral to a reduced-pressure delivery tube 2217. The reduced-pressure delivery tube 2217 includes a central lumen 2223 and a plurality of secondary lumens 2225. While the auxiliary lumen 2225 may be used to measure pressure at or near the tissue site, the auxiliary lumen 2225 may further be used to purge the central lumen 2223 to prevent or dissolve obstructions. A plurality of apertures 2231 communicate with the central cavity 2223 to distribute the reduced pressure delivered by the central cavity 2223. As shown in fig. 50, preferably, the aperture 2231 does not pass through the secondary cavity 2225. Also shown in fig. 50 is a countersunk end of the reduced-pressure delivery tube that increases the head space 2241 at the end of the auxiliary chamber 2225. If tissue, scaffold, or other material engages the end of the reduced-pressure delivery tube 2217 during application of reduced pressure, the head space 2241 continues to allow the delivery of cleaning fluid to the central cavity 2223.

In operation, the reduced pressure delivery system 2111, 2211 of fig. 40-50 may be applied directly to a tissue site to distribute reduced pressure to the tissue site. The low-profile shape of the primary manifold is highly desirable for the percutaneous installation and removal techniques described herein. Similarly, the main manifold may also be inserted surgically.

Referring to fig. 51, primary manifolds 2115, 2215 may be used in conjunction with secondary manifold 2321. In fig. 51, secondary manifold 2321 includes two layers of felted mat. The first layer of secondary manifold 2321 is placed in contact with a bone tissue site that includes a fracture. Primary manifold 2115 is placed in contact with the first layer, and the second layer of secondary manifold 2321 is placed on top of primary manifold 2115 and on the first layer. Secondary manifold 2321 allows fluid communication between primary manifold 2115 and the tissue site, but prevents direct contact between the tissue site and primary manifold 2115.

Preferably, secondary manifold 2321 is bioabsorbable, which allows secondary manifold 2321 to remain in place, allowing reduced pressure therapy to be completed. When reduced pressure treatment is complete, the primary manifold 2115 may be removed from between the layers of the secondary manifold with little or no interference with the tissue site. In one embodiment, the primary manifold may be coated with a lubricious or hydrogel-forming material to facilitate removal from between the layers.

The secondary manifold preferably acts as a scaffold for new tissue growth. As a scaffold, the secondary manifold may comprise at least one substance selected from the group consisting of: polylactic acid, polyglycolic acid, polycaprolactone, polyhydroxybutyrate, polyhydroxyvalerate, polydioxanone (polydioxanone), polyorthoester (polyorthoester), polyphosphazene, polyurethane, collagen, hyaluronic acid, chitosan, hydroxyapatite, calcium phosphate, calcium sulfate, calcium carbonate, bioglass, stainless steel, titanium, tantalum, allografts, and autografts.

The purging functions of the reduced pressure delivery systems 2111, 2211 described above may be used with any of the manifolds described herein. The ability to purge the manifold or conduit that delivers the reduced pressure prevents blockage formation that could impede the application of the reduced pressure. These obstructions typically form when the pressure near the tissue site reaches equilibrium and the outflow of fluid around the tissue site becomes slow. It has been found that purging the manifold and reduced pressure conduit with air at selected intervals for a selected amount of time helps to prevent or dissolve obstructions.

More specifically, the air is conveyed through a second conduit separate from the first conduit conveying the reduced pressure. The outlet of the second conduit is preferably proximate to the outlet of the manifold or the first conduit. While air may be forced or "pushed" into the outlet of the second conduit, the air is preferably drawn out of the second conduit by the reduced pressure at the tissue site. It has been found that in many instances, delivering air for 2 seconds at 60 second intervals during the application of reduced pressure is sufficient to prevent obstruction formation. This purging scheme provides sufficient air to adequately move the fluid within the manifold and first conduit while preventing the introduction of too much air. Introducing too much air, or introducing air at too high a time interval frequency, will result in the reduced pressure system not being able to return to the target reduced pressure between cleaning cycles. The selected amount of time for delivering the cleaning fluid and the selected time interval at which the cleaning fluid is delivered typically vary depending on the design and size of the system components (e.g., pumps, piping, etc.). However, the air should be delivered in an amount and frequency high enough to adequately clear the blockage while allowing the full target pressure to be restored between cleaning cycles.

Referring to fig. 52, in one illustrative embodiment, the reduced pressure delivery system 2411 includes a manifold 2415 fluidly connected to a first conduit 2419 and a second conduit 2423. The first conduit 2419 is connected to a reduced pressure source 2429 to provide a reduced pressure to the manifold 2415. The second conduit 2423 includes an outlet 2435, the outlet 2435 disposed in fluid communication with the manifold 2415 proximate to the outlet of the first conduit 2419. The second conduit 2423 is fluidly coupled to a valve 2439, the valve 2439 being configured to allow communication between the second conduit 2423 and ambient air when the valve is placed in an open position. The valve 2439 is operably connected to a controller 2453, the controller 2453 being capable of controlling the opening and closing of the valve 2439 to regulate purging of the second conduit with ambient air to prevent blockages within the manifold 2451 and the first conduit 2419.

It should be noted that any fluid, including liquids or gases, may be used to implement the cleaning techniques described herein. While the driving force for the cleansing fluid is preferably the extraction of reduced pressure at the tissue site, the fluid may similarly be delivered by a fluid delivery device similar to that discussed with reference to fig. 9.

According to the systems and methods described herein, applying reduced pressure tissue treatment to a tissue site may be accomplished by applying a sufficient reduced pressure to the tissue site and then maintaining the sufficient reduced pressure for a selected period of time. Alternatively, the reduced pressure applied to the tissue site may be periodic in nature. More specifically, the amount of reduced pressure applied may vary according to a selected time period. Yet another method of applying reduced pressure may randomly vary the amount of reduced pressure. Similarly, the rate or volume of fluid delivered to the tissue site may be constant, periodic, or random in nature. The fluid delivery, if periodic, may occur during periods when reduced pressure is applied, or may occur during periods of cycling when reduced pressure is not applied. While the amount of reduced pressure applied to the tissue site will generally vary depending on the pathology of the tissue site and the circumstances under which the compression tissue treatment is applied, the reduced pressure is generally between about-5 mm Hg and-500 mm Hg, but more preferably between about-5 mm Hg and-300 mm Hg.

Although the systems and methods of the present invention have been described with reference to tissue growth and healing in human patients, it should be recognized that these systems and methods for applying reduced pressure tissue treatment may be used in any living organ where it is desirable to promote tissue growth or healing. Similarly, the systems and methods of the present invention may be applied to any tissue, including without limitation, bone tissue, adipose tissue, muscle tissue, neural tissue, dermal tissue, vascular tissue, connective tissue, cartilage, tendons, or ligaments. While tissue healing may be a focus of the application of reduced pressure tissue treatment as described herein, the application of reduced pressure tissue treatment may also be used to generate tissue growth in non-diseased, non-defective, or damaged tissue, particularly tissue located beneath the skin of a patient. For example, it may be desirable to apply reduced pressure tissue treatment using percutaneous implantation techniques to grow additional tissue at the tissue site, which may then be harvested. The harvested tissue may be transplanted to another tissue site to replace diseased or damaged tissue, or alternatively the harvested tissue may be transplanted to another patient.

It is also important to note that the reduced pressure delivery apparatus described herein may be used in conjunction with a scaffold material to increase the growth and rate of growth of new tissue. The scaffold material may be disposed between the tissue site and the reduced pressure delivery apparatus, or the reduced pressure delivery apparatus itself may be made of a bioresorbable material that acts as a scaffold for new tissue growth.

It should be apparent from the foregoing that an invention having considerable advantages has been provided. While the invention is shown in only some of its forms, it is not so limited but is susceptible to various changes and modifications without departing from the spirit thereof.

Claims (46)

1. A reduced pressure delivery system for applying a reduced pressure tissue treatment to a tissue site, comprising:

a primary manifold having a flexible wall surrounding a primary flow passage and adapted for placement adjacent a tissue site, the flexible wall including an inner surface having a plurality of projections extending from at least a portion of the inner surface and into the primary flow passage, the flexible wall further including a plurality of apertures extending through the flexible wall and communicating with the primary flow passage;

a first conduit fluidly connected to the primary flow passage to convey a reduced pressure through the primary flow passage and the plurality of apertures; and

a second conduit having at least one outlet proximate the primary flow passage or at least one outlet of the first conduit to clear obstructions at or near the at least one outlet of the first conduit.

2. The system of claim 1, wherein the first and second conduits are part of a multi-lumen tube.

3. The system according to claim 2, wherein the flexible wall and multi-lumen tube are co-extruded.

4. The system of claim 1, wherein

The first and second conduits are part of a multi-lumen tube;

the flexible wall is connected at one end to the multi-lumen tube; and is

The primary flow passage is capped at an end of the flexible wall opposite the end connected to the multi-lumen tube.

5. The system of claim 1, wherein the second conduit is at least partially disposed within the flexible wall.

6. The system of claim 1, wherein the flexible wall is comprised of a medical grade silicone polymer.

7. The system of claim 1, wherein the flexible wall is substantially rectangular in cross-section.

8. The system of claim 1, wherein the flexible wall is substantially cylindrical along at least a portion of its axial length.

9. The system of claim 8, wherein the substantially cylindrical flexible wall subtends an arc of 360 degrees.

10. The system of claim 1, wherein the projection prevents blockage of the primary flow passage by preventing the flexible wall from completely collapsing during application of reduced pressure through the primary flow passage.

11. The system of claim 1, wherein the tissue site comprises tissue selected from the group consisting of: adipose tissue, muscle tissue, nerve tissue, skin tissue, vascular tissue, connective tissue, cartilage, tendons, and ligaments.

12. The system of claim 1, further comprising a secondary manifold adapted to be placed adjacent to the primary manifold and to transfer reduced pressure from the primary manifold to a tissue site.

13. The system of claim 12, wherein the secondary manifold is bioabsorbable.

14. The system of claim 12, wherein the secondary manifold is a felted mat.

15. The system of claim 12, wherein the secondary manifold is a stent and comprises at least one substance selected from the group consisting of: polylactic acid, polyglycolic acid, polycaprolactone, polyhydroxybutyrate, polyhydroxyvalerate, polydioxanone, polyorthoester, polyphosphazene, polyurethane, collagen, hyaluronic acid, chitosan, hydroxyapatite, calcium phosphate, calcium sulfate, calcium carbonate, bioglass, stainless steel, titanium, tantalum, allogeneic grafts and autografts.

16. A reduced pressure delivery system for applying a reduced pressure tissue treatment to a tissue site, comprising:

a primary manifold having a flexible wall surrounding a primary flow channel and adapted for placement adjacent a tissue site, the flexible wall including a plurality of apertures therethrough in communication with the primary flow channel;

a microporous material disposed within the primary flow channel, the microporous material having a plurality of flow channels;

a first conduit fluidly connected to the primary flow passage to convey a reduced pressure through the primary flow passage, the cellular material, and the plurality of pores; and

a second conduit having at least one outlet proximate the primary flow passage or at least one outlet of the first conduit to clear obstructions at or near the at least one outlet of the first conduit.

17. The system of claim 16, wherein the first and second conduits are part of a multi-lumen tube.

18. The system according to claim 17, wherein the flexible wall and multi-lumen tube are co-extruded.

19. The system of claim 16, wherein

The first and second conduits are part of a multi-lumen tube;

the flexible wall is connected at one end to the multi-lumen tube; and is

The primary flow passage is capped at an end of the flexible wall opposite the end connected to the multi-lumen tube.

20. The system of claim 16, wherein the second conduit is at least partially disposed within the flexible wall.

21. The system of claim 16, wherein the flexible wall is comprised of a medical grade silicone polymer.

22. The system of claim 16, wherein the flexible wall is reinforced to prevent collapse under reduced pressure.

23. The system of claim 16, wherein the flexible wall is substantially rectangular in cross-section.

24. The system of claim 16, wherein the flexible wall is substantially cylindrical along at least a portion of its axial length.

25. The system of claim 24, wherein the substantially cylindrical flexible wall subtends an arc of 360 degrees.

26. The system of claim 16, wherein the cellular material prevents blockage of the primary flow passage by preventing the flexible wall from completely collapsing during application of reduced pressure through the primary flow passage.

27. The system of claim 16, wherein the tissue site comprises tissue selected from the group consisting of: adipose tissue, muscle tissue, nerve tissue, skin tissue, vascular tissue, connective tissue, cartilage, tendons, and ligaments.

28. The system of claim 16, wherein the microporous material is a reticulated, polyurethane foam.

29. The system of claim 16, further comprising a secondary manifold adapted to be disposed adjacent to the primary manifold and to deliver reduced pressure from the primary manifold to a tissue site.

30. The system of claim 29, wherein the secondary manifold is bioabsorbable.

31. The system of claim 29, wherein the secondary manifold is a felted mat.

32. The system of claim 29, wherein the secondary manifold is a stent and comprises at least one substance selected from the group consisting of: polylactic acid, polyglycolic acid, polycaprolactone, polyhydroxybutyrate, polyhydroxyvalerate, polydioxanone, polyorthoester, polyphosphazene, polyurethane, collagen, hyaluronic acid, chitosan, hydroxyapatite, calcium phosphate, calcium sulfate, calcium carbonate, bioglass, stainless steel, titanium, tantalum, allogeneic grafts and autografts.

33. A reduced pressure delivery system for applying a reduced pressure tissue treatment to a tissue site, comprising:

a primary manifold having a flexible wall surrounding a primary flow passage and adapted for placement adjacent a tissue site, the primary manifold including an occlusion prevention member disposed within the primary flow passage, the flexible wall including a plurality of apertures therethrough in communication with the primary flow passage;

a secondary manifold disposed adjacent to the primary manifold and adapted to contact a tissue site such that the secondary manifold is in fluid communication with the primary manifold, but adapted to prevent contact between the primary manifold and the tissue site;

a first conduit fluidly connected to the primary flow passage to convey a reduced pressure through the primary flow passage and the plurality of apertures.

34. The system of claim 33, wherein the blockage prevention member is a plurality of projections disposed on an inner surface of the flexible wall and extending into the primary flow passage.

35. The system of claim 33, wherein the blockage prevention member is a cellular material disposed within the primary flow passage.

36. The system of claim 33, wherein the secondary manifold is bioabsorbable.

37. The system of claim 33, wherein the secondary manifold is a felted mat.

38. The system of claim 33, wherein the secondary manifold is a stent and comprises at least one substance selected from the group consisting of: polylactic acid, polyglycolic acid, polycaprolactone, polyhydroxybutyrate, polyhydroxyvalerate, polydioxanone, polyorthoester, polyphosphazene, polyurethane, collagen, hyaluronic acid, chitosan, hydroxyapatite, calcium phosphate, calcium sulfate, calcium carbonate, bioglass, stainless steel, titanium, tantalum, allogeneic grafts and autografts.

39. A method of promoting tissue growth at a tissue site, comprising:

surgically placing a primary manifold adjacent a tissue site, the primary manifold having a flexible wall surrounding a primary flow passage, the flexible wall including a plurality of apertures therethrough in communication with the primary flow passage, the primary manifold further including an occlusion prevention member disposed within the primary flow passage;

surgically placing a secondary manifold in contact with a tissue site such that the secondary manifold is in fluid communication with the primary manifold, but contact between the primary manifold and the tissue site is prevented; and

delivering a reduced pressure to a tissue site through the primary channel, the plurality of holes, and the secondary manifold.

40. The method of claim 39, wherein the blockage prevention member is a cellular material disposed within the primary flow passage, the cellular material having a plurality of flow channels.

41. The method of claim 39, wherein the blockage prevention member is a plurality of projections extending from an inner surface of the flexible wall and into the primary flow passage.

42. The system of claim 39, wherein the secondary manifold is a felted mat.

43. The system of claim 39, wherein the secondary manifold is a stent and comprises at least one substance selected from the group consisting of: polylactic acid, polyglycolic acid, polycaprolactone, polyhydroxybutyrate, polyhydroxyvalerate, polydioxanone, polyorthoester, polyphosphazene, polyurethane, collagen, hyaluronic acid, chitosan, hydroxyapatite, calcium phosphate, calcium sulfate, calcium carbonate, bioglass, stainless steel, titanium, tantalum, allogeneic grafts and autografts.

44. The method of claim 39, further comprising:

after the reduced pressure tissue treatment is complete, the primary manifold is percutaneously removed.

45. The method of claim 39, further comprising:

percutaneously removing the primary manifold after the reduced pressure tissue treatment is complete; and is

Wherein the secondary manifold is bioabsorbable.

46. The method of claim 39, further comprising purging the primary flow passage with ambient air to prevent blockages within the primary flow passage.