HK1118742B - Externally-applied patient interface system and method - Google Patents

Abstract

A tissue closure treatment system and method are provided with an external patient interface. A first fluid transfer component FTCl comprises a strip of porous material, such as rayon, with liquid wicking properties. FTCl can be placed directly on a suture line for transferring fluid exuded therethrough. An underdrape is placed over FTCl and includes a slot exposing a portion of same. FTC.2 comprises a suitable hydrophobic foam material, such as polyurethane ether, and is placed over the underdrape slot in communication with FTCl. Negative pressure is applied to FTC2 through a connecting fluid transfer component FTC.3. A negative pressure source can comprises a manual device or a power-operated suction device. The tissue closure method includes a manual operating mode using a manual suction device with an automatic shut off for discontinuing suction when a predetermined volume of fluid has been drained. An automatic operating mode utilizes a microprocessor, which can be preprogrammed to respond to various patient and operating conditions. The method proceeds through several phases with different components in place and different patient interface functions occurring in each.

Description

Externally applied patient interface system and method

Technical Field

The present invention relates generally to medical devices and methods for treating closed wounds and incisions and for controlling moisture therein, and more particularly to systems and methods for draining and/or irrigating tissue separations such as surgical incisions and for compressing and stabilizing anatomical or injured areas using ambient air pressure generated by an external patient interface component (external patient interface component) and a vacuum source.

Background

Tissue separation may result from surgical procedures and other causes such as traumatic wounds and chronic wounds. Various medical procedures are used to separate and close tissue. An important consideration involves securing separate tissue portions together to promote closure and healing. Incisions and wounds may be closed with sutures, staples, or other medical closure devices. The "first healing" (primary healing) in surgery is the "closing" of the incision. For load bearing tissues such as bone, fascia and muscle, this requires considerable material, assuming it is suture material, staples or plates and screws. For a wound to be "closed," the epithelial layer must be sealed. To achieve this, the "load-bearing" areas of the skin and subcutaneous layers (i.e., the deep dermal elastic layer and the superficial fascia or fibrous layer of adipose tissue, respectively) must also remain at least approximately long enough to form collagen deposits to hold the separated portions together.

Other important considerations include controlling bleeding, reducing scarring, eliminating the likelihood of hematoma, seroma, and "dead space" formation, and controlling pain. Dead space problems are more likely to occur in subcutaneous closures. Relatively shallow incisions are typically closed by surface-applied closure techniques such as sutures, staples, adhesives, and strips of adhesive tape. However, deeper incisions may indeed require not only skin surface closure, but also time consuming placement of multiple suture layers within the load-bearing plane.

Prevention of infection is another important consideration. Topical treatments include various antibiotics and dressings (dressing) that control or prevent bacteria at the incision or wound site. Infections can also be systematically managed and controlled with appropriate antibiotics and other drugs.

Other tissue separation treatment objectives include minimizing the trauma and scarring effects of surgery and minimizing edema. Accordingly, various closure techniques, post-operative procedures and medications are used to reduce post-operative swelling, bleeding, seromas, infections and other undesirable post-operative side effects. Because the considerations of isolated tissue are very common in the medical field, including most surgery, effective, convenient, infection-free, and aesthetic tissue closure is highly desirable from the standpoint of both the patient and the health care practitioner. Thus, the systems, interfaces and methods of the present invention may be widely practiced and may provide widespread benefits to many patients.

Fluid control considerations are typically associated with treating tissue separation. For example, in surgical incisions, subcutaneous bleeding occurs in the fascia and muscle layers. Therefore, in order to drain such incisions, a deep drain tube (deep drain tube) is generally installed. In recent years, autotransfusion has become more widespread as equipment and techniques for re-infusing patient whole blood have made considerable progress. Such procedures have the advantage of reducing dependence on donated blood and its inherent risks. Serous fluids also typically flow from the incision and wound site, thus requiring drainage and disposal. Within a few days of the initial healing period, new incisions and wounds typically shed blood and other fluids on the surface of the patient's skin, particularly along the suture and staple lines, while the separated tissue portions close along the suture and staple lines.

Another area of fluid control relates to irrigation. Various irrigants are supplied to the isolated tissue region for anti-infection, anesthesia, introduction of growth factors, and to otherwise promote healing. An effective fluid control system preferably provides both drainage and irrigation functions, either sequentially or simultaneously.

Typical orthopaedic surgical procedures include total joint replacement of the hip, knee, elbow, shoulder, foot and other joints (TJR). The resulting tissue separation is often subject to bending and movement associated with articulation of the replacement joint. Although the joints may be immobilized as a treatment option, atrophy and stiffness often begin and prolong the healing period. A better option is to restore joint function as soon as possible. Thus, an important goal of orthopaedic surgery involves the use of a patient to quickly maximize recovery of their extremities within a maximum range of motion.

Similar considerations arise with respect to various other medical procedures. For example, arthrotomy, repair, and cosmetic procedures, including flap and scar repair, also require tissue closure and are often subject to motion and stretching. Other examples include incisions and wounds in thick or unstable subcutaneous tissue areas where splinting of the skin and subcutaneous tissue can reduce dehiscence of deep sutures. The requirement to move the limb and the entire patient conflicts with the limitations of currently available external compression and tissue stabilization methods. For example, various types of bandage wraps and compression knitwear are commonly used for these purposes, but none provide the advantages and benefits of the present invention.

The above-described procedures, as well as many other applications discussed below, may benefit from a tissue closure treatment system and method having a surface application patient interface for fluid control and external compression.

Post-operative fluid drainage can be achieved with various combinations of tubes, sponges and porous materials suitable for collecting and draining fluid. The prior art includes techniques and methods for aiding drainage. For example, U.S. patent nos. 4,969,880, 5,100,396, 5,261,893, 5,527,293 and 6,071,267 to zaierowski disclose the use of pressure gradients, i.e., vacuum and positive pressure, to assist in the drainage of fluids from wounds, including surgical incision sites. Such a pressure gradient may be established by applying a porous sponge material to the wound either internally or externally, covering the wound with a permeable, semi-permeable or impermeable membrane, and connecting a suction device vacuum source thereto. The fluid drawn from the patient is collected for disposal. This method of fluid control has proven to be a significant advance in patient healing. Fluid management, post-surgical and other aspects relate to the application of fluids to a wound site for irrigation, infection control, pain control, growth factor application, and the like. Wound drainage devices are also used to achieve fixation and securement of tissue, thus aiding healing and closure. This can be accomplished by an internally closed wound drainage device and an externally open wound vacuum apparatus applied to the wound surface. Fixation of the adherent tissue can also be achieved by suture tip-over dressing, taping, and (contact) casting.

Tissue stabilization and fixation may be beneficial for surgical wounds and incisions, which may promote cell migration and cell and collagen binding. This benefit of tissue stabilization and fixation can occur in many procedures, including fixation of bone fractures and suturing for the purpose of left and right skin layer fixation.

Moisture control is another key aspect of surgical wound care involving blood and exudates in deep tissues and exudates at or near the skin surface. For example, the moist state should be set at the epithelial layer first to facilitate cell migration. A state of tissue desiccation should then occur in order to promote the development of a functional keratin layer. Humidity control may also be effective in controlling bacteria that may be discharged along with the discharged fluid. Residual bacteria can be greatly reduced by the wound drying procedure. In some cases, this two-stage wet-dry sequence of treatments may provide satisfactory bacterial control and eliminate or reduce the dependence on antibiotics and preservatives.

At the same time as this stage, an effective treatment protocol can be maintained stable and secure while preventing destructive forces within the wound. The treatment regimen should also treat varying amounts of wound exudate, including the maximum amount of wound exudate that typically exudes during the first 48 hours post-surgery. Closed drainage procedures generally involve a tubular drainage device placed within a surgical incision. Open drain procedures may use gauze dressings and other absorbent products for absorbing fluids. However, many previous fluid handling procedures and products often require additional cleaning steps, exposure of the patient and health care professional to fluid contaminants, and frequent dressing changes. Moreover, insufficient drainage may result in residual blood, exudates, and exudates being isolated within the tissue plane near the surgical incision.

Still further, certain hemorrhages and other subcutaneous discomfort can be treated by applying a compressed hemostat at the skin surface. Thus, fluid free edema (free fluid edema) resorption can be accelerated.

To date, no externally applied patient interface system and method having the advantages and features of the present invention has been available.

Disclosure of Invention

In the practice of the present invention, systems and methods are provided for enhancing closure of separated tissue portions using a surface applied patient interface. Subsurface drainage, irrigation and autotransfusion components may optionally be used in conjunction with the external interface of the surface application. The external interface may advantageously be placed on a suture or staple line and comprise a first transfer component comprising a strip of porous material, such as rayon, which is applied directly to the patient to transport or transfer the fluid by capillary action to a second transfer component comprising a sponge or foam material. A lower sterile drape (endrappe) is placed between the transfer elements for passing fluid therethrough through a lower sterile drape opening, such as a slit. An over-drape (overlape) is placed over the second transfer member and the surrounding skin surface. The patient interface is connected to a negative pressure source, such as a vacuum assisted closure device, wall suction (wall suction), or mechanical suction pump. The manual control embodiment utilizes a finite volume fluid reservoir (fine capacity fluid reservoir) with a shut-off valve to interrupt drainage when a predetermined amount of fluid is collected. An automatic control embodiment utilizes a microprocessor adapted to program operation of the negative pressure source in response to various inputs. The closed wound or incision treatment method of the present invention includes three phases of fluid control activity that correspond to different phases of the healing process. In the first stage, active drainage is applied. In the second stage, the components may be separated independently or sequentially. In a third stage, the second transfer component may optionally be left in place for protection and to assist in evacuating any residual fluid from the suture/staple line through the first transfer component.

In other embodiments of the invention, the components of the dressing system may be pre-made for efficient application. The foam blocks may be provided with a full or partial rayon cover and a conformable upper antiseptic drape. An access panel (access panel) with a reclosable seal may be mounted on the upper drape to contact the foam block and the wound area. The pre-made outer dressing may be provided with a shroud that receives the foam block, which may be accessed for replacement or reorientation by a reclosable seal. Treatment area access is also provided by sealing strips. The system may also be used as a hemostat.

Brief description of the drawings

The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.

FIG. 1 is a schematic block diagram of a tissue closure process and system embodying the present invention.

FIG. 2 is a perspective view of the separation of incised tissue with a deep drainage tube installed.

FIG. 3 is a perspective view thereof showing the separated tissues sutured together at the skin.

FIG. 4 is a perspective view thereof showing separated tissues sutured together at a deep skin layer beneath the skin surface.

Fig. 5 is a perspective view thereof showing a first fluid transfer component (ftc.1) of a synthetic fiber strip and a lower sterile drape placed over the sutures.

Fig. 6 is a perspective view thereof showing the ftc.1 and lower sterile drape in place over the suture.

Fig. 7 is a perspective view thereof showing a second fluid transfer component (ftc.2) in place.

Figure 8 is a perspective view thereof showing the upper antiseptic drape in place.

Fig. 9 is a perspective view thereof showing the connecting fluid transfer component (ftc.3) in place for connecting the system to a negative pressure source.

Fig. 10 is a cross-sectional view thereof, taken generally along line 10-10 in fig. 9, and particularly illustrating ftc.3.

Fig. 11a is a perspective view thereof showing ftc.3 removed and the upper antiseptic drape scored for ventilation.

Fig. 11b is a perspective view thereof showing the patient interface removed along the perforated tear line in the lower and slit lines in the upper sterile drape.

FIG. 11c is a perspective view of a patient interface suitable for pre-packaging, application to a patient, and connection to a negative pressure source.

Figures 12a-12d show an alternative embodiment of an elbow attachment device ftc.3a-3d, respectively.

Fig. 12e, 12f show a modified ftc.2a with a removable wedge to facilitate articulation such as bending of a patient's joint.

Fig. 12g, 12h show an alternative embodiment external patient interface assembly.

Figures 13a-13c include flow charts illustrating methods of tissue closure treatment embodying the present invention.

Fig. 14 is a schematic block diagram of an automated tissue closure processing system including an alternative embodiment of the present invention.

Fig. 15 is a cross-sectional view of an alternative embodiment automated tissue closure treatment system.

FIG. 16 is a partial flow diagram of a method for automated tissue closure processing that embodies an alternative embodiment of the present invention.

FIG. 17 is a partial perspective view of a tissue closure treatment system including an alternative embodiment of the present invention having a reclosable access panel.

FIG. 18 is a perspective view of a reclosable access panel.

FIG. 19 is a cross-sectional view of the tissue closure system taken generally along line 19-19 of FIG. 18.

Fig. 20 is an enlarged cross-sectional view of the tissue closure system, particularly showing the reclosable seal thereof.

FIG. 21 is a perspective view of the tissue closure system showing the sealing strip open.

FIG. 22 is a perspective view of the tissue closure system showing the seal open and the foam bun removed.

Fig. 23 is a cross-sectional view of an outer dressing assembly which includes an alternative embodiment of the present invention.

Fig. 24 is a cross-sectional view of an alternative embodiment tissue closure system having inner and outer foam blocks.

Fig. 25 is a cross-sectional view of the system shown in fig. 24, illustrating the gradual healing of tissue in the wound.

FIG. 26 is a cross-sectional view of the system shown in FIG. 24, showing epidermal reimplantation of the wound.

FIG. 27 is a cross-sectional view of a foam bun partially encased in rayon.

Fig. 28 is a cross-sectional view of an alternative embodiment tissue closure system with an outer foam block and an inner foam block assembly.

Fig. 29 is a cross-sectional view thereof, shown partially collapsed at ambient atmospheric pressure.

FIG. 30 is a perspective view of an alternative construction dressing having a reclosable seal and a fluid access port.

Fig. 31 is a perspective view of the underside of the dressing showing the intermediate backing strip (backing strip) removed.

Figure 32 is a perspective view of the dressing showing the side backing strip removed.

Figure 33 is a perspective view of a dressing having a squeeze bulb evacuator shown therein connected to a fluid port.

Figure 34 is a perspective view of the dressing shown partially collapsed at atmospheric pressure.

Figure 35 is a perspective view of the dressing showing the seal open.

Figure 36 is a perspective view of the dressing showing the foam bun removed.

FIG. 37 is a cross-sectional view of a foam bun fully encapsulated in rayon.

Fig. 38 is a perspective view of a dressing with an alternative embodiment of a discrete liner and foam bun.

Figure 39 is a perspective view of the dressing showing the foam bun removed.

Fig. 40 is a perspective view of the dressing showing the liner removed.

Fig. 41 is a cross-sectional view of a dressing having an alternative embodiment of a shroud floor comprising a wicking material.

Fig. 42 is a cross-sectional view of a dressing system with an alternative embodiment of a covered foam core migration element.

Figure 43 is a perspective view showing the dressing compressed under pressure therein.

Fig. 44 is a top plan view thereof.

Figure 45 is a cross-sectional view thereof showing the dressing configuration prior to application to a patient and taken along line 45-45 of figure 44.

Fig. 46 is a top plan view including multiple dressing applications covering an elongated tissue separation, such as a surgical incision.

Fig. 47 is a perspective view of a wound with a drainage strip installed in preparation for closure.

Figure 48 is a cross-sectional view of a dressing comprising an alternative embodiment of the invention having upper and lower rayon layers.

Figure 49 is a cross-sectional view thereof wherein the dressing is compressed.

Fig. 50 is a cross-sectional view of a dressing comprising a rayon cover with an encapsulating reticulated foam core according to an alternative embodiment of the present invention.

Fig. 51 is a cross-sectional view thereof, wherein the dressing is compressed.

Figure 52 is a cross-sectional view of a dressing comprising an alternative embodiment of the invention with a sensor connected to a controller.

Figure 53 is a perspective view of an experimental model of a dressing for viewing fluid flowing therethrough.

FIG. 54 is a graph showing wet surface area versus liquid volume for reticulated foam cores under various conditions.

Fig. 55 is a cross-sectional view of a hemostat including an alternative embodiment of the present invention.

Best mode for carrying out the invention

I. Introduction and Environment

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.

Tissue closure System 2

Referring in more detail to the drawings, reference numeral 2 generally designates a tissue closure processing system embodying the present invention. As shown in FIG. 1, the system 2 is adapted for use on a patient 4 having an incision or wound 6, the incision or wound 6 being closable by a suture 8 comprised of a suture 10, staple, or other suitable medical fastener.

The patient interface 12 consists of an optional deep drain device 14 and an external patient interface 16, the deep drain device 14 being connected to a deep drain device negative pressure source 15 associated with a deep drain reservoir 17, the external patient interface 16 comprising a first fluid transfer component ftc.1 comprising a synthetic fiber strip or other suitable porous material, a lower sterile drape 20 generally covering the ftc.1 and comprising a slit 20a, a second fluid transfer component ftc.2 comprising a hydrophobic sponge (hydrophilic sponge), and an upper sterile drape 24.

The fluid handling subsystem 26 includes a deep drain negative pressure source 15 and a surface drain negative pressure source 28, which may be combined where a general negative pressure source and collection container are preferred. The negative pressure sources 15, 28 may be operated manually or under electrical power. Both types of examples are well known in the medical field. For example, a Manually Operable Portable Vacuum Source (MOPVS) is shown in U.S. Pat. No.3,115,138, which is incorporated herein by reference. MOPVS, under the trademark HEMVAC _ is available from Zimmer corporation of Dover, Ohio. For example, the ball-type activator shown in U.S. patent No.4,828,546 (incorporated herein by reference) and commercially available from Surgidyne corporation of Eden Prairie, minnesota can be used on smaller wounds for shorter durations or in a multiplex system. Also, THE electrically driven vacuum device may be provided by a vacuum assisted closure device (vacuum assisted closure device) available from Kinetic conceptals of San Antonio, texas under THE trademark tee VAC-. Still further, many health care facilities, particularly hospitals and clinics, are equipped with an aspirator system with an aspirator source that is useful at a wall mounted outlet.

A limited volume reservoir 30 is fluidly connected to the negative pressure source 28 and is adapted to discharge to a waste container 32. A shut-off valve 34 is associated with the reservoir 30 and is adapted to automatically interrupt drainage when the reservoir 30 is filled to a predetermined volume.

An optional autotransfusion subsystem 36 may be connected to the deep drainage device 14 and adapted to re-infuse the patient 4 with his or her own blood. U.S. patent No.5,785,700 discloses such an autotransfusion system with a portable detachable vacuum source, commercially available from Zimmer corporation, and is incorporated herein by reference.

Fig. 2 shows an incision 6, the incision 6 forming first and second separated tissue portions 38a, 38b having incision edges 40a, 40 b. The incision 6 extends from the skin 42 and opens at the skin 42, through the deep skin layer 44 and subcutaneous layer 46, approximately to the fascia 48. The deep drainage tube 50 is placed in the lower part of the incision 6 and penetrates the skin 42 at the opening 52.

Fig. 3 shows the cut edges 40a, 40b secured together by stitches 54, the stitches 54 forming a stitch line 8 at the skin surface 42. As an alternative to suture 10, various other medical fasteners such as staples may be used. Fig. 4 shows the suture 10 disposed in a deep skin layer 44 below the skin surface 42.

Fig. 5 shows the application of ftc.1 on top of the suture 8. Ftc.1 preferably comprises a suitable porous capillary material, such as rayon, which is well suited for transporting fluid seeping along suture 8 by capillary action. Rayon also tends to dry relatively quickly and thus effectively migrate fluids therethrough. The lower drape 20 is placed over ftc.1 and adjacent skin surface 42. The slit 20a of the lower drape 20 is generally centered along the centerline of the ftc.1 and lies directly over the stitch line 8. The ftc.1 and lower drape 20 may be preloaded in a roller or some other suitable structure suitable to facilitate placement on suture 8 at any desired length. Fig. 6 shows ftc.1 in place and the lower sterile drape 20.

Fig. 7 shows the second fluid transfer component ftc.2 installed. It preferably comprises a suitable hydrophobic foam material, such as polyurethane ether (PUE), which comprises a reticulated lattice-type (foam) material capable of being collapsed by vacuum forces (negative pressure) so as to exert a positive "shrink-wrap" type compression on the skin surface, while still maintaining channels that allow fluid to pass through. As shown, its footprint is slightly smaller than that of the lower drape 20, thus providing a lower drape edge 20 b. Alternatively, the capillary layer of ftc.1 can be sized to equal or nearly equal the footprint of ftc.2. This structure is suitable for prefabrication as a separate pre-installed liner that can be used by simply removing the release layer backing from the adhesive-backed lower sterile drape. This configuration is also suitable for easy removal and replacement of the central portion of the assembly in its entirety without removing drapes that have adhered to the skin if removal and replacement is the desired clinical option rather than a single application that is removed or extended in stages.

Fig. 8 shows the upper drape 24 placed over the ftc.2 and the lower drape 20 with edge 24a extending beyond the lower drape edge 20b and contacting the patient's skin surface (dermis) 42. Fig. 9 and 10 show a patch connector 58 mounted on ftc.2 and comprising a core 58a of hydrophobic foam (PUE) material sandwiched between layers 58b of sterilising cover fabric. The vacuum drainage tube 60 includes an inlet end 60a embedded in the foam core 58a and extends between the sterilization drape layers 58b to an outlet end 60b connected to the surface drainage negative pressure source 28.

Fig. 11a shows ftc.3 removed, for example, by cutting away a portion of the antiseptic drape 24 to provide an antiseptic drape opening 54. In addition, the upper sterile drape 24 may be cut at 55 to further ventilate the ftc.2. Draining ftc.2 under negative pressure, and further drying it with air circulation (fig. 11a) can provide significant healing advantages by reducing the growth of various microorganisms in ftc.2 that require a humid environment. Thus, such microorganisms and the various toxins produced may be vaporized, neutralized, and otherwise prevented from re-entering the patient. Control of microorganisms may also be achieved by injecting a sterilant and flushing various components of patient interface 12, including drapes 20, 24; FTC.1; ftc.2 and ftc.3.

Fig. 11b shows patient interface 12 removed along perforated tear line 56 of the lower sterile drape and cut line 59 in upper sterile drape 24. Thus, it will be appreciated that substantially the entire patient interface 12, except for the lower and upper drape edges 20b, 24a, may be removed to access the sutures 8 and dermis 42 for visual inspection, evaluation, cleaning, suture removal, dressing change (e.g., using a prepackaged patient interface 12a as shown in fig. 11 c), consideration of further processing options, and the like. For example, the upper disinfecting drape 24 may be cut around the perimeter or footprint of the ftc.2 to allow removal thereof. Preferably, ftc.2 is readily releasable from lower drape 20 and ftc.1, whereby ftc.2 can be grasped and lifted upwardly to facilitate passing a scalpel through upper drape 24 and into the space between the underside of ftc.2 and lower drape 20. The ftc.1 may then optionally be removed by tearing the upper drape 20 along the tear line 56 of the upper drape 20 and removing the upper drape 20 as shown in fig. 11 b.

Fig. 11c shows a prepackaged patient interface 12a suitable for an initial or "dressing change" application. Optionally, the strip of rayon ftc.1 may have the same configuration or "footprint" as the foam sponge ftc.2, thus eliminating the need for the lower drape 20. Prepackaged patient interface 12a may be sterile packaged for placement directly on suture 8. Alternatively, the patient interface components may be prepackaged individually or in a suitable set of subassemblies that include all of patient interface 12. For example, the lower and upper sterile drape/ftc.1 and ftc.2 subassemblies, respectively, may be individually prepackaged. Patient interfaces of various sizes and component configurations may be prepackaged for application as dictated by the particular patient condition. Preferably, certain sizes and configurations tend to be relatively "universal" and thus suitable for use in a particular medical procedure, such as TJR, thereby simplifying patient interface checklists. Alternatively, the individual components may be assembled in various sizes and configurations for "custom" applications.

Fig. 12a-12d show alternative attachment fluid transfer components ftc.3a-3d for attaching ftc.2 to a surface drainage negative pressure source 28. Ftc.3a (fig. 12a) shows a patch connector having a similar construction to ftc.3 and adapted to be placed anywhere on the upper drape 24. Ftc.3a is equipped with a luer lock connector (Leur lock connector) 62. Ftc.3b (fig. 12b) includes a strip of hydrophobic (PUE) foam material partially covered by the upper antiseptic drape 24, which may be configured as a wrap around a limb or extremity 66 of the patient. Ftc.3c (fig. 12c) is an elbow type connector. Ftc.3d (fig. 12d) is a corrugated elbow connector adapted to accommodate deflection of vacuum drain tube 60.

Fig. 12e, 12f show an alternative construction of ftc.2a with a plurality of removable wedges 57, where the wedges 57 are formed and adapted to adjust articulation, e.g. joint bending. Thus, the flexibility of ftc.2a may be substantially enhanced for patient comfort, mobility and flexibility. Such wedges may extend laterally and/or longitudinally relative to the ftc.2a. Ftc.2a functions in a similar manner whether wedge 57 is in place or removed.

Fig. 12g shows an improved patient interface 312 with the lower sterile drape 20 placed under ftc.1. This configuration allows for removal of ftc.1 without disturbing the lower drape 20. Fig. 12h shows a further improved patient interface 412 in which ftc.1 has the same configuration or footprint as ftc.2, whereby they can be manufactured and bonded together. The lower sterile drape 20 may be omitted in this configuration.

Treatment method

Fig. 13a-13c include flow charts of methods embodying the present invention. The method proceeds from start 70 to patient diagnosis and assessment at 72 and treatment planning at 74. The deep drainage device 14 is installed as desired at 76 and the incision is sutured at 78. The surface interface component 12 is applied at 80 and connected to an external component (i.e., negative pressure source 15, 28) at 82. The collection reservoir volume is preset at 84 based on such factors as wound/incision characteristics, blood flow rate, etc.

Stage 1

Deep drainage occurs at 86 and active surface drainage occurs at 88, both of which are affected by negative pressure sources 15, 28. The negative pressure source 28 partially collapses the PUE foam ftc.2, which in turn causes the upper antiseptic drape 24 to move downward and apply a positive compressive force to the closed wound or incision 6. In the closed environment of patient interface 12, such forces are effectively confined to the ambient atmosphere. This restrictive control feature protects the patient from excessive forces exerted by patient interface 12. A stabilizing force of up to one atmosphere applied across the closed wound or incision 6 acts like a splint or plaster bandage in controlling edema and promoting the healing process.

A "reservoir full" condition is detected at 90 and an interrupt surface branching into 92 drains the negative pressure, after which the contents of the reservoir are inspected and processed at 94. If surface bleeding is detected by visual inspection at decision block 96, the method branches to the "discontinue active surface drainage" step at 98. If at decision block 100, the suture is actively draining, then the method loops to the active surface drainage step 88 and continues, otherwise the active surface drainage is interrupted at 98, i.e., when the wound/incision is neither bleeding nor exuding fluid.

Phase 1 is generally characterized by deep drainage (interactive or passive) and active surface drainage under the action of manual or electric suction means. The normal duration is approximately two to three days during which post-operative or post-traumatic swelling generally reaches its maximum and begins to subside.

Stage 2

Fig. 13b shows a view of "removing parts in stages? "decision block 102 begins phase 2. A positive determination results in the independent deactivation and removal of components at 103, including the interruption of the active suction device at 104, which transitions the hydrophobic PUE foam (ftc.2) internal pressure from negative to positive and allows the collapsed ftc.2 to expand again at 106, potentially increasing the surface compound pressure from ambient conditions to positive. Preferably, this transition occurs without applying excessive pressure to the surface from the decompressed expanded ftc.2. During phase 1, negative pressure (i.e., suction/vacuum) tends to compress ftc.2 and correspondingly deflate the upper drape 24, thereby increasing the compression applied by ftc.2. When the application of negative pressure is interrupted manually or automatically, the ftc.2 inflates again against the constraint of the upper sterile drape 24 and presses against the skin 42 with equal and opposite reaction, in particular along the seam 8. Thus, ftc.2 can automatically transition from ambient conditions to positive pressure simply by interrupting the application of the vacuum source.

The positive pressure applied to the skin 42 continues to compress and stabilize the tissue along the suture 8 (step 108) to reduce swelling and cooperates with the operation of the ftc.1 and ftc.2 to continue drainage by evaporation at the suture 8 at step 110. A negative decision at decision block 102 results in the interface being removed at 112 and, if processing is not to be terminated, results in the suture being checked and processed at 113 and the interface being replaced at 114, which may involve all or part of patient interface 12. Thereafter, the method continues to stage 3.

Stage 3

Fig. 13c shows stage 3 of the treatment method, where the deep drainage is interrupted and the tube is removed at 118. The over-drape 24 and ftc.2 are removed at 120, 122, respectively. The lower drape 20 and ftc.1 are preferably configured to allow visual inspection of the suture 8 therethrough at 124. When the suture 8 is sufficiently closed, the lower drape 20 and ftc.1 are removed at 126 and the process ends at 128. Alternatively, all or a portion of interface 12 may be replaced and processing continued at stage 3, as indicated by the patient condition.

Alternative embodiment tissue closure system 202

Fig. 14 schematically illustrates a tissue closure system 202 comprising an alternative embodiment of the present invention, which includes a microprocessor or controller 204, the microprocessor or controller 204 being connectable to one or more sensors 206 coupled to the patient interface 12 for sensing various conditions associated with the patient 4. Microprocessor 204 may be programmed to operate solenoid 208 coupled to valve 210, valve 210 being associated with reservoir 30 and controlling fluid flow caused by negative pressure source 228 through its connection to patient interface 12.

Fig. 15 shows a tissue closure system 202 having a microprocessor 204 connected to a plurality of sensors 206a, 206b, 206c, each associated with a flow control member, e.g., a valve 210a, 210b, 210c, respectively. Each flow control member 210a, 210b, 210c is associated with a respective negative pressure source 228a, 228b, 228c, which in turn controls the discharge of fluid into the canister or reservoir 212a, 212b, 212c, respectively. For example, patient interface 12 may include an external patient interface 16 and a pair of deep drains 50a, 50b as described above. Patient interface 12 includes an optional supply component 214, and optional supply component 214 may include one or more reservoirs, pumps (manual or powered), and associated controllers that may be connected to microprocessor 204 for system control. The supply component 214 is optionally connected to one or more tubes 50, 60 for delivering fluid to the patient through the deep drainage tube 50 or through the external patient interface 16. Such fluids may include, for example, antibiotics and aesthetic agents, irrigation agents, growth factors, and any other fluid that is beneficial for promoting healing, combating infection, and improving patient comfort.

A treatment method using the alternative embodiment tissue closure system 202 is shown in fig. 16 and generally includes a modified pretreatment 230 and a stage 1 procedure. The method proceeds from "start" to a diagnosis/assessment step 234, a treatment planning step 236, a deep drainage device installation 238, suturing at 240, an external interface component application 242, a microprocessor programming 244, and connection of application components at 246, such as connection of tubes. Stage 1 with deep drainage at 248, active suction device interface at 250, and "suture active drainage? Decision block 252 begins. If the suture is actively draining, the method loops back to the active suction device interface step 250, otherwise (negative decision at 252) it proceeds to stage 2.

Applications of V

Without limiting the generality of the useful applications of the tissue closure systems 2 and 202 of the present invention, the following partial list represents possible patient conditions and procedures that may dictate the application of the present invention.

● relates to a closed tissue separation, such as a surgical incision.

● pertains to joints in which the incision undergoes motion and extension, such as arthrotomy, reconstructive procedures, cosmetic procedures, flaps, scar revision, Total Joint Replacement (TJR) procedures, i.e., hip, knee, elbow, shoulder, and foot.

● in thick or unstable subcutaneous tissue areas, wherein the clamping of the skin and subcutaneous tissue reduces the dehiscence of deep sutures.

● in reconstructing the wound at the time of the procedure, wherein irregular cavities are created. These cavities include the resection of tumors, grafts, bone, and other tissues. Changes in limb length and geometry, as well as changes in the size, location and contour of bones and other deep structures.

● wounds in which elimination and prevention of dead space is important.

● handling of hematomas and seromas.

● stumps are amputated.

● abdominal, thoracic, lumbar and other wounds in which splinting of the wound may help to close and mobilize the patient during the post-operative time interval.

● in areas of fragile or sensitive skin, where repeated removal and replacement of tape or other adhesive can cause skin pain, irritation, or blistering in the vicinity of the wound. In addition, among other things, dressing changes can cause tissue shearing or displacement, so that substantial wound healing is compromised.

● in the event that the patient wishes to shower before the skin has healed sufficiently to allow for wounds that are not contaminated by bath or shower water.

● are susceptible to wounds contaminated with feces, urine and other body fluids.

● pediatric, geriatric, psychiatric and neurological patients, and other patients who may interfere with dressings and wounds.

● patients with multiple consultants and caregivers, where repeated examination of the wound may compromise healing.

● deep closure and surface sutures and staples.

● or any clean surgical or traumatic incision that is open or closed completely or partially by sutures, or in which the skin edges may be juxtaposed to a gap no wider than the width of the negative pressure zone of the dressing, i.e., in which the maximum separation is less than or equal to the width of FTC.1 (rayon band).

● in cosmetic and reconstructive surgery, the system and method of the present invention can control and hide the effects of early bleeding, oozing, subcutaneous bleeding and edema in the wound.

● in the surgery of limbs where compression and drainage by this method can eliminate or reduce the need for a surrounding compressive wrap.

● tend to prolong tissue separation for drainage, such as hip and knee incisions, and tend to inhibit tissue separation in healthy conditions such as diabetics that heal. Reduced hospitalization may be caused by decreased swelling and control of drainage.

Case study

● general concept: foam (ftc.2) is applied to the continuous surface of surgical sites and other wounds. Air drying at the suture is facilitated by a synthetic fiber strand (ftc.1).

● stage 1: active or passive deep drainage (drainage tubes); active suction applied to surface PUE foam (placed on top of surgical incision, draining bleeding and exudates from suture); actively pumping compressed PUE foam, thus applying positive compression to the entire anatomical region; an adhesive-backed under-film sterile drape having an MVTR of 3-800 on the skin underlying the PUE foam; a strip of rayon (or other suitable porous capillary material) on the suture; drapes (MVTR of 3-800) were sterilized on a similar type of adhesive film that was overlaid on the PUE foam.

● duration: about 2-3 days, the effective time from active drainage of the incision/suture to cessation and drying of the suture to healing.

● stage 2: active suction is stopped by cutting off the (elbow) connector and leaving the ftc.2 in place. Released from suction, the ftc.2 inflates against the upper sterile drape and applies a positive pressure differential to the surgical site. Sustained slight compression can be maintained throughout phase 2; continued drying of the suture is provided by the rayon strands and into the residual drainage function of the ftc.2. The deep drain remains in place during phase 2 for active deep drainage.

● duration: about three days, i.e., 3-6 days after surgery.

● stage 3: removing the upper disinfecting drape and FTC.2; leaving the lower sterile drape and the rayon strip in place; visually observing the wound healing process; transparency is desired.

● duration: for a few (e.g., up to three) weeks.

● clinical trials confirmed that: closure of the surgical site in the upper thoracic region of patients with severe healing problems showed good results and rapid wound healing.

● sub-cuticular (subcuticular) sutures avoid interference with the rayon strands and require early removal of the sutures or pressure on the skin sutures under a compressible black sponge.

● selecting: pressure transducers are used for interface pressure mapping of the wound site and automated control, and pressure, flow, etc. are monitored.

Alternative embodiment tissue closure system 302

A tissue closure system 302 including an alternative embodiment of the present invention is shown in fig. 17-22. The system 302 is adapted to close a wound 304 with the lesion field 306 just above the fascia and the superior tissue separation 308 primarily within the dermis and subcutaneous layer. A wedge-shaped inner fluid transfer member (foam block) 310 is located within the tissue separation zone 308 and is mounted between side drapes 312 on either side of the wound 304. An outer fluid transfer member (foam block) 314 is placed on top of the inner member 310 and the side drape 312 and covered by an outer drape 316. The optional innermost foam piece 330 may be positioned within the damage region 306 and sized to fit within the damage region 306, as well as may migrate fluids and gradient forces to and from the inner foam piece 310.

A reclosable access panel 318 is placed over the opening formed in the outer drape 316 and includes an adhesive-coated perimeter 320 surrounding an adhesive-free central region 322 with a reclosable seal 324 extending longitudinally along a centerline thereof. The sealing strip 324 includes a rib or bead 326 that is releasably captured within a channel 328 (fig. 20).

In operation, the reclosable access panel 318 is adhesively secured around its perimeter 322 to the outer drape 316 and provides access to the foam blocks 310, 314 of the dressing system 302. For example, the replaceable foam blocks 310, 314 (fig. 21 and 22), the treatment may be applied, and the wound healing process may be visually monitored.

Alternative external dressing 402

Fig. 23-27 show an outer dressing 402 that can be pre-made or pre-installed and used for various wound treatment and closure applications. The dressing 402 includes a foam block 404 partially enclosed within a rayon cover 406, the rayon cover 406 including an open top 408, the open top 408 being secured to an upper perimeter 410 of the foam block 404, such as by stitching, staples, adhesive, or some other suitable mechanical fastener as shown at 412. The dressing 402 is preferably pre-loaded with an outer drape 414, the outer drape 414 including a foam-covered central portion 416 and a surrounding patient-contacting skirt portion 418. A hemmed edge 420 is formed at the intersection of the drape portions 416, 418 and partially beneath the foam block 404 to protect the skin and prevent the formation of a low pressure vacuum chamber around the foam block 404 where blisters may otherwise occur. In operation, the dressing 402 can be easily replaced by cutting, removing the foam block 404 and drape outer portion 416 around the edge 420. Thus, the wound can be inspected, cleaned, removed, treated, etc., and the new dressing 402 can be put in place. The skirt portion 418 of the original dressing that contacts the patient may remain in place.

Fig. 23 shows fluid flow (discharge) direction arrows 421 from elbow coupling 417 and discharge tube 419. Alternatively, fluid may be injected into the dressing 402 through the tube 419 and the coupling 417. Water pressure/gas compression force arrow 423 is shown in fig. 23 and represents a downward (i.e., into the patient) force that may be established by compressing the foam block 404 under suction and then releasing the negative pressure differential, thus converting the dressing to a positive pressure differential. In the positive pressure differential mode of the procedure, dressing 402 controls edema by pressing foam pads 404 against tissue adjacent the wound. There are many potential medical benefits to controlling edema in this manner. For example, healing may be promoted, scar tissue minimized, and patient discomfort may be reduced.

Fig. 24 shows the outer dressing 402 used in conjunction with an inner foam block 422, the foam block 422 being located beneath the dermis at the top of the subcutaneous layer. The inner foam block 422 is adapted to apply a pressure differential within the subcutaneous layer, thereby promoting tissue growth and closure. The inner/outer configuration of the dressing system shown in fig. 24 can repair and soften the wound edges 424, while the wound edges 424 have been contracted and stiffened, stabilized and edematous by applying a pressure differential across the outer and inner foam blocks 404, 422, such as a pressure for controlling edema (positive pressure differential).

Fig. 25 shows a wound confined to the dermis 426 with another foam block 428 in place. The subcutaneous layer is substantially healed. Fig. 26 shows the outer foam block 404 in place, alone used to pull the wound edges 430 together at the epidermis. Fig. 27 shows an outer foam block 404 covered on the sides and bottom by a rayon cover 406, leaving an open top 408.

IX. dressing system 502 of an alternative embodiment

Fig. 28 shows yet another alternative embodiment of an inner/outer dressing system configuration 502 having an outer foam block 504 and an inner foam component 506, the outer foam block 504 being similar to the foam block 404 described above, and the inner foam component 506 being located within the dermis and subcutaneous layers. The assembly 506 is comprised of a proximal inner foam piece 508, the proximal inner foam piece 508 may be located at the bottom of the subcutaneous layer on top of the fascia within a wound cavity 510 formed by the wound, while a distal inner foam piece 512 is located primarily in the dermal and subcutaneous portion of the wound between the outer foam piece 504 and the proximal inner foam piece 508.

The dressing system configuration 502 can be configured and reconfigured as needed to accommodate different wound configurations in different stages of healing. For example, when the lesion cavity 510 is closed, the proximal inner foam piece 508 may be removed. Likewise, the distal inner foam pad 512 may be removed as the subcutaneous layer and dermis heal. Also, in connection with dressing changes, and depending on changes in wound configuration, foam blocks 504, 508, and 512 may be replaced with foam blocks of different sizes as desired. Such dimensions and configurations may be selected to optimize the beneficial effects of pressure gradients (positive and negative), fluid control, edema control, antimicrobial measurements, irrigation, or other treatment protocols. Still further, the access panel 318 described above may be used in conjunction with the dressing system 502 to provide access to its foam pad and to the wound itself.

Fig. 29 shows the inner/outer dressing system 502 compressed under the vacuum effect of the outer vacuum source, with the drape 316 pulled tightly down over the compressed outer foam block 504. Thus compressed, the system 502 is adapted to deliver a compressive force of a positive pressure differential to the wound area.

X. alternative embodiment dressing assembly 602

Figures 30-37 show a reclosable, pre-installed external dressing assembly 602 that includes an alternative embodiment of the present invention. The dressing assembly 602 includes a foam block 604, which foam block 604 may be completely covered in rayon 606 or some other suitable material having desirable absorbent and/or wicking properties. The foam block 604 also includes a core 605, the core 605 comprising a suitable material such as polyurethane, hydrophobic foam. Alternatively, other foam materials having hydrophobic or hydrophilic properties may be utilized. Foam blocks 604 of various sizes and shapes may also be used, including cutting and trimming it to a size during a medical procedure.

The foam bun 604 is removably placed within a reclosable shield 608 that includes a base plate 610, the base plate 610 optionally being covered by removable adhesive backing strips 612, 614, and 616 that form a central opening 618. As shown in fig. 31, the central opening 618 in the bottom plate 610 is initially covered by the central backing strip 614. The central backing strip 614 is removed, exposing the foam bun 604 through the opening 618. The reclosable shield 608 also includes a top panel 620 with a reclosable seal 622 extending from one end to the other and generally longitudinally centered. The seal 622 may be similar in structure to the reclosable seal 324 described above. The top plate 620 also includes fluid ports 624, 626, which fluid ports 624, 626 may include, for example, luer lock connectors or some other suitable fluid connection device.

The shroud 608 may comprise polyethylene or some other suitable material selected based on performance criteria such as permeability, flexibility, biocompatibility, and antimicrobial characteristics. In medical applications where healing may be promoted by exposure to air circulation, various permeable and semi-permeable materials are commonly used as skin drapes. For applications where continuous vacuum suction may be utilized and where the dressing 602 is not required to be airtight, the shroud 608 may be formed of the materials described above.

The dressing assembly 602 may be pre-manufactured or customized for a particular application from suitable components according to embodiments of the method of the present invention. In a pre-made protocol, the dressing 602 is preferably pre-sterilized and packaged in sterile packaging.

The dressing 602 is typically applied over a newly closed surgical incision for controlling bleeding and other fluid exudation. For example, the dressing 602 may be placed on a patient with its floor opening 618 on the suture 636 (fig. 36). The central backing strip 614 is peeled away from the backplane 610 to expose the openings 618 and the adhesive 628 on the backplane 610 (fig. 33). The openings 618 provide fluid migration, which may also be provided by constructing the shroud floor 610 from a permeable material or by providing other channel configurations therethrough. Thereafter, the dressing 602 may be placed on the patient with the floor adhesive providing temporary securement. As shown in fig. 32, the side backing strips 612, 616 can then be removed and the base plate 610 fully secured to the patient.

The fluid ports 624, 626 are adapted to draw out or inject fluid or both, depending on the particular treatment method. For extraction, a vacuum source may be connected to one or both ports 624, 626 and may include a source of mechanical dynamic pressure differential, such as a wall suction. Alternatively, a hand-operated mechanical suction device may be provided, such as a suction bulb 630 (fig. 33) or a Hemovac apparatus available from Zimmer corporation of warraw, indoana. Such hand-operated suction devices are adaptable to the mobility of the patient and tend to be relatively simple to operate. The powered suction device and fluid pump apparatus may be preprogrammed to provide intermittent and alternating suction and infusion, and automatically respond to patient condition feedback signals. As shown in fig. 33, the application of a negative pressure differential (suction) causes the shroud 608 to collapse onto the foam bun 604. Thus, the various dynamic fluid forces and fluid motion effects described above can be implemented and controlled.

Fig. 34 shows the shroud 608 further collapsed on the foam block 604 as a result of evacuation from the two fluid ports 624, as indicated by fluid flow arrows 632. Ambient air pressure arrows 634 show the application of this force, which tends to collapse the shroud 608 against the foam block 604.

Figure 35 shows the seal 622 open to access the interior of the dressing 602. Next, the foam block 604 can be removed, as shown in fig. 36, whereby the suture 636 can be visually inspected and/or treated. The foam blocks 604 may be inverted or replaced as desired. Fig. 37 shows a cross-section of a foam bun 604, the foam bun 604 may be completely encased in rayon or some other suitable capillary material 606 to accommodate placement against either side of the stitch line 636.

Xi. alternative embodiment dressing assembly 702

Figs. 38-40 show a dressing assembly 702 that includes an alternative embodiment of the invention and includes a foam bun 704, the foam bun 704 comprising any suitable hydrophobic or hydrophilic foam material. The foam bun 704 is selectively and removably positioned within a shroud 708 similar to the shroud 608 described above. The liner 706 may comprise a piece of rayon or some other suitable material suitable for wicking fluid from the stitching 636 to the foam bun 704 and further suitable for isolating the patient from direct contact with the foam bun 704. The liner 706 may be sized to lie against the floor of the shield 708.

In a dressing suitable for wound inspection, wound treatment, and component replacement procedures in surgery, the dressing assembly 702 is adapted to readily utilize available components, such as the foam block 704 and the liner 706, all without having to remove the hood or interfere with its adhesive attachment to the patient. Fig. 39 shows the removal of a foam block 704 that can be inverted for reuse or replacement. Fig. 40 shows a liner that is also easily replaceable upon removal. With the liner 706 removed, the suture 636 is exposed for suture removal, inspection, handling, irrigation, and other procedures. Thereafter, the shroud 708 may be reclosed and vacuum-assisted and/or other processes may be resumed.

Xii. alternative embodiment dressing assembly 802

A dressing assembly 802 comprising an alternative embodiment of the invention is shown in figure 41 and comprises a foam block 804 in a hood 806 adapted to be opened and closed by a reclosable seal 808. The shroud 806 includes an upper drape portion 810, and the upper drape portion 810 may include a suitable semi-permeable or impermeable drape material. The shroud 806 includes a perimeter 812, which perimeter 812 may be provided with an optional adhesive perimeter seal 813 adapted to provide a relatively fluid-tight seal around the shroud 806. The perimeter seal 813 may be relatively narrow to minimize patient discomfort, skin maceration, and the like. The floor 814 comprises a suitable capillary material, such as rayon, and extends to the shroud perimeter 812. The material comprising the dressing 802 may be selected for permeability or occlusive, biocompatibility, hydrophobic or hydrophilic response to fluids, bacteriostatic (bacteriostatic) and antibacterial properties, and other performance-related properties and criteria.

In operation, the dressing 802 is placed over a wound or suture of a patient. The perimeter adhesive 813 can provide temporary fixation and sealing. A strip of tape 816 may be placed on the shroud perimeter 812 for securing the shroud 806 in place. As described above, fluid migrates through the capillary material layer 814 to the foam block 804 for evacuation through a suitable fluid connector connectable to a vacuum source. Furthermore, the dressing 802 is adapted to provide a positive pressure gradient, as also described above. The sealing strip 808 allows access to the foam block 804 for inversion or replacement, as indicated.

The foam block 804, drape upper portion 810, and wicking material layer 814 may be assembled to be independently movable so that only connections intermediate these components occur around the perimeter 812 where the drape upper portion 810 connects to the wicking material layer 814. The independent free movement described above allows the dressing assembly 802 to reconfigure itself to conform to the patient and various applied forces, such as pressure gradients. Thus, the individual components can expand and contract independently of one another without deforming the other components or interfering with the performance and comfort of the dressing assembly 802.

Xiii. alternative embodiment dressing system 902

A dressing assembly 902 including another alternative aspect or embodiment of the invention is shown in fig. 42-46 and includes a dressing 904, the dressing 904 being adapted to control application of positive compression and/or negative suction to a patient having an incised tissue separation 906. Without limitation to the generality of the useful application of the system 902, the incision 906 may comprise a surgical incision, which may optionally be closed with sutures 908 or other suitable wound closure procedures including staples, adhesives, tapes, and the like. The incision 906 may include a closed suction drain 910 in the bottom of the incision, the suction drain 910 may be brought to the skin surface by puncturing the incision using well-known surgical procedures.

The dressing 904 includes a dressing cover 909 having an optional perimeter base ring (perimeter base ring)912, the base ring 912 comprising a semi-permeable material with a skin compatible adhesive layer 914 applied to its underside. Prior to application of the dressing 904, the base loop adhesive 914 mounts a release paper backing 916 (fig. 45) having a release tab 917 (fig. 44). The base ring 912 defines a central proximal opening 918, and the dressing 904 opens downwardly through the opening 918. The cover superstructure 920 includes a distal panel 922, a perimeter 924 generally defining a folded foldable edge, and a proximal return ring 926 secured to the base ring 912 at another folded foldable edge about a central opening 918. Thus, the base and return rings 912, 926 form a nested dual thickness base structure 928 suitable for expansion and collapse. A distal housing opening 930 is formed in the distal plate 922 and connects to a flexible, wave-shaped collapsible shield that is in turn mounted on a length of rigid tubing 934 that terminates distally in a connector 936, the connector 936 including, for example, a needleless luer lock hub or other suitable tubing connection/closure device such as an air valve. Tube 934 includes a proximal end 935 that communicates with the interior of dressing cover 909.

An optional migrating component or element 938 is disposed within enclosure 909 and exposed through its central opening 918. The migrating component 938 optionally includes a compressible mesh core 940, and the compressible mesh core 940 may include, for example, a polyurethane ether foam material selected for its hydrophobic, resilient and memory properties. The migration assembly 938 also includes a porous flexible liner 942, the liner 942 comprising a material such as Owens surgical dressing, which has liquid wicking properties and biocompatibility to directly contact the skin of a patient.

The application of the post-operative incision dressing is particularly suited to the same situation, without limitation to the generality of useful applications of the dressing system 902. The dressing 904 may be pre-packaged and aseptically packaged for opening under sterile conditions, such as those typically maintained in an operating room. The central opening 918 can be sized to accommodate the tissue separation 906 with sufficient overlap so that the perimeter base ring adhesive 914 bonds to healthy skin around the area of the tissue separation 906 and outside the underlying internal surgical anatomical region. Multiple dressings 904 may be placed from end to end (fig. 46) or side-by-side to effectively cover a relatively long incision 950. In such multiple dressing applications, the sutures 952 may be covered with an interposed barrier strip (barrier strip)948 at the location where the adhesive-coated base loops intersect, again for patient comfort. The barrier layer strips 948 may include, for example: xeroform-gauze available from Integrated Medical Devices, Inc. of Elwood, N.J.; vaseline _ gauze; or Owens rayon tape.

The base ring adhesive 914 preferably forms a relatively fluid tight joint around the treated area. Optionally, base ring 912 may include a suitable semipermeable membrane material having suitable gas permeability characteristics to enhance patient comfort and avoid impregnation in the contact area. A suitable differential pressure source 944 is coupled to the plumbing connector 936. Without limitation, the pressure source 944 can include an automatic and manual pressure source. For example, automated wall suction devices are commonly available in operating rooms and elsewhere in healthcare facilities.

For a post-operative incision dressing, the wall suction may be connected to the connector 936, the dressing 904 evacuated, and the wall suction disconnected, whereby the connector 936 seals the system. It will be appreciated that a balanced "steady state" condition may be achieved using positive ambient air pressure acting externally on the dressing cover 909 and the internally compressed migration assembly 938, thus applying a compressive force to the incision 906 and surrounding area via the compressive force arrows 939 (fig. 43).

For example, fig. 43 shows the collapsed dressing 904 with the rayon dressing liner 942 extended beyond the polyurethane ether foam core 940 and formed a dual thickness liner perimeter 946 located within the double folded cover perimeter 924. In this configuration, any liquid exudate from the incision 906 is effectively transported away from the incision 906 by capillary action of the rayon liner 942 via fluid migration arrows 941. Within a short period of time, typically one or two days after surgery, a jet of serum blood fluid is expected from the incision line. The capillary action of the rayon liner 942 in combination with the minor circulation of ambient air through the semipermeable base ring 912 maintains the incision 906 and its surrounding healthy skin relatively dry to avoid maceration. The pressure differential provided by the components of the dressing 904, in combination with the capillary action described above, may also facilitate the extraction and removal of wound exudate. With the dressing 904 in its compressed configuration (fig. 43), the tube proximal side 935 can engage and be pushed into the migration element 938 for direct fluid migration therebetween.

The emptied dressing 904 provides many medical incision closure and healing benefits. The stabilizing and securing effect on the incision and surrounding tissue resulting from the force exerted by the dressing 904 tends to promote contact healing, as opposed to gap healing or healing in which opposing edges slide and move one over the other. Furthermore, edema and subcutaneous hematoma control is achieved by applying a positive pressure compressive force in the compressed core 940 via the compressive force arrows 939, the compressed core 940 tends to resume its pre-compressed shape and volume as the pressure within the dressing 904 is released. Thus, the effects of restricting or controlling leakage around base ring 912, for example, tend to be offset by the controlled expansion of core 940. Limited air movement through the dressing 904 may be advantageous for controlling internal moisture, reducing maceration, and the like.

The system 902 is adapted to be adjusted and replaced as needed during the closing and healing of the incision. Additional air replacement may be performed from an automatic or manual source via connector 936. Wall suction, mechanical pumps and other automated sources may be employed. The manual vacuum source includes: a squeeze-type ball (630 in fig. 33); a Hemovac _ evacuator commercially available from Zimmer corporation of Warsaw, Ind; and a vacuum tube. Inspection of the incision 906 may be accomplished by making an L-shaped incision in the dressing cover superstructure 920 and pulling or lifting the migration assembly 938 to expose the incision 906. The migration component 938 may be reversed or replaced. The dressing 904 may then be released by applying the replacement portion of the cover 909, and the dressing 904 may then be emptied, as described above. After processing is complete, the cover superstructure 920 may be cut away and the migration component 938 may be discarded. The base ring 912 may be peeled away from the skin or simply left in place until the adhesive 914 is released.

The steady fixation and closure forces associated with the dressing 904 tend to promote healing by maintaining the separated tissue portions in contact with each other and by controlling and/or eliminating lateral movement of the tissue, which may prevent healing. The positive pressure compressive force component associated with the force in the dressing 902 tends to close the tissue separation 906 and hold the opposing tissue edges in fixed contact with each other, thereby promoting healing. Various other dynamic forces that tend to shift the wound edges relative to one another may be effectively resisted.

Alternative embodiment external dressings 1002, 1012

Fig. 47-49 show an alternative embodiment external dressing 1002. As shown in fig. 47, the wound 6 may be prepared by placing an optional drainage strip 1004 between the wound edges and folding the strip distally over the adjacent skin surface. The use of such strips is well known. A class of latex known as Penrose drainage devices (Penrose drain) is available from Davol corporation of Cranston, rholand. A class of silicone rubbers known as Swanson incision drainage devices is available from Wright Medical Technology corporation of Arlington, tennessee. Alternative deep wound devices for withdrawing fluids include drains, such as those described above, and other devices. Alternatively, such drainage devices may be omitted from incisions that do not require enhanced drainage. Also, the drainage strip 1004 may be placed on a fluid-migrating backing strip, such as rayon, "gauze" dressing or backing, "N-face" backing, or the like, to increase efficiency and prevent skin maceration.

Fig. 48 shows a dressing 1002 that includes a fluid transfer member 1006 having a reticulated foam core or block 1008 (e.g., polyurethane ether described above), the reticulated foam core or block 1008 having a surface 1009 and distal/upper and proximal/lower wicking material (e.g., rayon or other suitable wicking material) layers 1010, 1012, the wicking material layers 1010, 1012 optionally being bonded to the core 1008 or loosely placed on the core 1008. The membrane drape 1014 is placed over the fluid transfer member 1006 and releasably adhered to healthy skin adjacent the incision 6. The elbow coupling 417 is placed over the opening 1016, and the opening 1016 forms a vent in the membrane drape 1014. The coupling 417 is connected to a suction device or negative pressure source, as also described above. When the negative pressure source is activated, the fluid motion tends to concentrate laterally (horizontally) along the bottom capillary layer 1012 towards the perimeter of the fluid transfer component 1006. The pressure differential between the fluid transfer member 1006 and the surrounding atmosphere compresses the core 1008, as shown in FIG. 49. For example, compression in the range of about 20% to 80% is feasible. As a result, the rayon layers 1010, 1012 are drawn closer together, particularly around the perimeter of the fluid transfer component 1006, thereby facilitating fluid transfer therebetween. Still further, the upper rayon layer 1010 tends to pull laterally inward under negative pressure, while the lower rayon layer 1012 tends to retain its original shape and size as it is placed on the skin. The upper rayon layer 1010, which is less compressible than the foam core 1008, therefore tends to deflect downward around its perimeter edge, further facilitating fluid flow to the upper rayon layer 1010 and the drain coupler 417. The exposed perimeter edges of the core 1008 facilitate movement of air into the core 1008, such as through a membrane 1014 that may comprise a semipermeable material, into the core 1008.

Fig. 50 and 51 show another alternative embodiment dressing assembly 1022 in which the foam core 1024 is completely encapsulated in a layer 1026 of wicking material (e.g., rayon or other suitable wicking material). Fig. 51 shows the dressing 1022 after application of negative suction pressure, which can bend or crimp the rayon layer 1026 adjacent to the lower portion of the core peripheral edge, thus providing an extended, curved capillary material double-layer edge 1028. The edge 1028 may provide an additional interface to the patient's skin, thereby avoiding or reducing pressure-related issues such as shear blister(s). The rim 1028 may provide another benefit in the form of enhanced air flow for a dry mode of skin suppuration, which is a requirement for long-term (three days to three weeks) post-operative dressings.

Yet another alternative embodiment dressing system includes the use of the dressing assembly 1022 during the initial heavy exudation phase, which typically occurs about 48-72 hours after surgery. Thereafter, the dressing 1002 can be removed and the rayon-encapsulated dressing assembly 1022 is suitable for the prolonged (typically about three days to three weeks) post-operative exudation phase. Alternatively, the rayon wicking material layer may be applied separately to continue wicking-assisted fluid drainage of exudate. The tissue is thus stabilized for important early collagen strength gains and for exudate removal, thus allowing the incision 6 and drainage site to be "sealed" and promoting drying of the skin surface.

Fig. 52 shows yet another embodiment of a wound dressing 1032 having a sensor 1034 that communicates with the dressing 1032 and provides input signals to a controller 1036, which may include a feedback loop 1038 for controlling various operating parameters of a system including the wound dressing 1032. For example, hemoglobin levels may be monitored as well as pressure, fluid flow, temperature, patient condition, and various effluent and exudate characteristics.

Figure 53 shows an experimental model 1042 of the dressing, oriented perpendicular to the model fluid flow in the system. Fluid tends to be present in the areas shown as the bottom 1044 along the sides 1046, 1048 of the reticulated polyurethane foam core 1050 and defining the fluid migration zones 1051. Air entrapment zone 1052, i.e., the top and center of foam core 1050, tends to trap air, whereby fluid tends to be drawn to the outer edges. Thus, polyurethane ether reticulated foams tend to trap air internally and move liquids externally. In this configuration, the break-off point in the ability to move liquid to the discharge elbow (discharge elbow)417 occurs at a liquid volume equal to about 10% of the volume of the uncompressed foam core 1050. Liquid absorption in reticulated foams can be enhanced by coating the channels thereof with protein.

Table I shows the compression effect of reticulated polyurethane ether foam at various negative pressure levels.

TABLE I

Effect of compression

	Volume (CC)	% compression
			Foam block (drying)	283.34	15
Drape with film	258.91	68
			Having 50mm Hg VAC	58.94	73
100mm	49.96	73
			150	42.41	77
Go back to 100	47.71	74
			Air rebalancing	133.95	28

FIG. 54 shows the total wet surface area of reticulated polyurethane foam as a function of increasing total liquid volume at different pressures, both uncoated and protein coated foam conditions.

Fig. 55 shows an active positive pressure hemostat 1062 that includes an alternative embodiment of the present invention and includes a patient interface 1064 having a transfer component 1066 for placement against a patient and an upper sterile drape 1068 placed thereon and secured to the surrounding skin. If the material comprising the core 1069 is not compatible with direct skin contact, the transfer component 1066 may include an optional liner or cap 1070 to directly engage the patient's skin. The transfer component 1066 communicates with a pressure source 1067 through an elbow coupling 417 over an opening or vent 1072 in the upper drape 1068. Application of negative pressure to the transfer component 1066 results in positive pressure being applied to the patient's skin by the transfer component 1066. The hemostat 1062 is adapted to provide localized compression for rapid resorption of the hydroedema-free fluid. Applications may include subcutaneous bleeding (e.g., 1074) and edema-free resorption in body cavities, internal organs and joints. Other applications may also utilize active pressure hemostasis device 1062, including cataplasm-type applications for enhanced absorption of topically applied drugs. As shown, the sensor 1034 and the controller 1036 can monitor various operating parameters to provide automatic control, particularly in conjunction with varying positive pressures applied by the transfer component 1066. For example, visible, thermal, and infrared indications of subcutaneous conditions may be detected by the sensor 1034, which outputs a corresponding signal for input by the controller 1036. The pressure may be cycled as appropriate and terminated when certain predetermined conditions are reached, e.g., corresponding to resorption of the edema-free material to achieve the treatment goal.

It should be understood that while certain embodiments and/or aspects of the present invention have been shown and described, the present invention is not so limited, but rather encompasses various other embodiments and aspects. For example, various suitable other materials may be substituted for those described above. The structure may also be modified as necessary to suit particular applications. Still further, various control systems may be configured and preprogrammed to automatically respond appropriately to different operating conditions. Still further, the above-described systems and methods may be combined with various other treatment protocols, drugs, and devices.

Claims (17)

1. A dressing assembly for closing a wound or incision, comprising:

an external patient interface comprising an external fluid transfer component adapted to transfer fluid from the wound or incision; the external patient interface comprises an upper drape placed over the external fluid-migrating component in contact with the surrounding skin surface;

the outer fluid transport component comprises a porous core having a surface; and

a cover of capillary material enclosing the porous core and comprising a layer of capillary material engaging the surface.

2. The dressing assembly of claim 1, comprising:

the upper antiseptic drape has an opening to the outer fluid-migrating component; and

the opening forms a drain for draining fluid from the dressing assembly.

3. The dressing assembly of claim 1, comprising:

an inner fluid transfer member positioned within the wound or incision in fluid communication with the outer fluid transfer member.

4. The dressing assembly of claim 3, wherein the inner fluid-migrating member comprises a drainage strip having an inner portion disposed within the wound or incision and an outer portion disposed outside the wound or incision.

5. The dressing assembly of claim 4, comprising:

a plurality of said drainage strips, each comprising a flat flexible material; and

the outer portion of each of the drainage strips is folded over the skin surface adjacent the wound or incision.

6. The dressing assembly of claim 2, comprising:

the porous core comprises proximal and distal surfaces and a peripheral edge extending therebetween;

the layer of capillary material comprises a proximal layer of capillary material engaging a proximal surface of the porous core and adapted to cover over the wound or incision, and a distal layer of capillary material engaging a distal surface of the porous core and the upper antiseptic drape.

7. The dressing assembly according to claim 2, wherein said porous core comprises a reticulated compressible foam material selected from the group consisting of polyurethane ether PUE and polyvinyl acetate PVA.

8. The dressing assembly according to claim 2, wherein said wicking material comprises rayon.

9. The dressing assembly of claim 1, comprising a pressure source connected to said outer fluid transfer member.

10. The dressing assembly of claim 9, comprising:

a fluid port mounted on the upper sterilization drape and connected to the pressure source.

11. The dressing assembly according to claim 9, wherein said pressure source comprises a manually operated vacuum-type device.

12. The dressing assembly of claim 1, comprising:

the wicking material cap includes a perimeter edge;

the outer fluid transfer member has a compressed configuration and an uncompressed configuration; and

the edges of the capillary material casing are curved and form laterally protruding edges, wherein the outer fluid transfer component is in the compressed configuration.

13. The dressing assembly of claim 2, comprising:

the porous core forming an air entrapment interior region with a negative pressure applied thereto;

the porous core forms a fluid migration zone at its outer surface and adjacent to the wicking material mantle; and

the fluid transfer region is adapted to direct fluid from the wound or incision to the vent.

14. The dressing assembly of claim 9, comprising:

a sensor connected to the outer fluid transfer component and adapted to sense a characteristic of the outer fluid transfer component and provide an output signal corresponding to the characteristic;

a controller connected to the sensor and receiving an input signal from the sensor and providing an output signal to the pressure source; and

a feedback loop connected to an output of the controller and the controller for providing a feedback signal corresponding to the output of the controller and inputting the feedback signal to the controller.

15. A dressing assembly for a wound or incision, comprising:

an external patient interface comprising an external fluid transfer component adapted to transfer fluid from the wound or incision; the external patient interface comprises an upper drape placed over the external fluid-migrating component in contact with a surrounding skin surface;

the outer fluid transfer component comprises a porous core having a surface;

the upper antiseptic drape has an opening to the outer fluid-migrating component;

the opening forming a drain for draining fluid from the dressing assembly;

an inner fluid transfer member disposed within the wound or incision in fluid communication with the outer fluid transfer member and comprising a plurality of drainage strips, each of the drainage strips having an inner portion disposed within the wound or incision and an outer portion disposed outside the wound or incision;

each of the drainage strips comprises a flat, flexible material;

the outer portion of each of the drainage strips is folded over the skin surface adjacent the wound or incision;

a pressure source connected to the external fluid transfer component;

a cover of capillary material enclosing the porous core and comprising a layer of capillary material; the wicking material cap includes a perimeter edge;

the outer fluid transfer member has a compressed configuration and an uncompressed configuration;

the edges of the capillary material cover are curved and form laterally protruding edges, wherein the outer fluid transfer component is in the compressed configuration;

the porous core forming an air entrapment interior region with a negative pressure applied thereto;

the porous core forms a fluid migration zone at its outer surface and adjacent to the wicking material mantle; and

the fluid transfer region is adapted to direct fluid from the wound or incision to the vent;

a sensor connected to the outer fluid transfer component and adapted to sense a characteristic of the outer fluid transfer component and provide an output signal corresponding to the characteristic;

a controller connected to the sensor and receiving an input signal from the sensor and providing an output signal to the pressure source; and

a feedback loop connected to an output of the controller and the controller for providing a feedback signal corresponding to the output of the controller and inputting the feedback signal to the controller.

16. A hemostat, comprising:

an external patient interface including an external fluid transfer component;

the external patient interface comprises an upper drape placed over the external fluid transfer component in contact with a surrounding skin surface and comprising a port;

the outer fluid transport component comprises a porous core having a surface;

a pressure source connected to the external fluid transfer component via the port; and

a cover of capillary material enclosing the porous core and comprising a layer of capillary material.

17. The hemostat of claim 16, comprising:

a sensor connected to the outer fluid transfer component and adapted to sense a characteristic of the outer fluid transfer component and provide an output signal corresponding to the characteristic;

a controller connected to the sensor and receiving an input signal from the sensor and providing an output signal to the pressure source; and

a feedback loop connected to an output of the controller and the controller for providing a feedback signal corresponding to the output of the controller and inputting the feedback signal to the controller.