Patent Publication Number: US-2018036465-A1

Title: Evacuating fluid surrounding devices implanted in body

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is related to and claims priority to U.S. Provisional Patent Application Ser. No. 62/372061, filed Aug. 08, 2016, entitled EVACUATING FLUID SURROUNDING DEVICES IMPLANTED IN BODY, the entirety of which is incorporated herein by reference. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     n/a 
     TECHNICAL FIELD 
     The present disclosure relates to kits and methods for implanting objects in the bodies of patients. 
     BACKGROUND 
     Certain surgeries involve implantation of an object in a cavity within the body of the patient. An object introduced within the body in a medical procedure and intended to remain in the body after completion of the procedure is referred to herein as an “implant.” For example, implantation of certain mechanical circulatory support devices (“MCSDs”) used to assist the pumping action of the heart involve implantation of a battery in a surgically-created cavity within the body. Such a battery or other implantable electronic device can provide power to the MCSD while the external power supply to the MCSD is temporarily interrupted. In some cases, the tissue surrounding the implant does not heal quickly or properly. This may leave the implant free to move within the cavity as the patient changes position, and may also lead to inflammation or even necrosis of tissue surrounding the cavity. This problem is particularly acute in cases where the implant is a relatively heavy object such as battery for an MCSD. Further improvement would be desirable. 
     SUMMARY 
     The present invention advantageously provides a method and kit for placing an implant in a patient. The method includes placing an implant consisting of at least one from the group consisting of an electronic device and an electromechanical device into a tissue cavity of the patient and evacuating fluid from the cavity and urging tissue surrounding the cavity to abut the implant. 
     In another aspect of this embodiment, the cavity is surgically created. 
     In another aspect of this embodiment, placing the implant into the cavity includes placing the implant through the surgically created opening in the tissue of the patient. 
     In another aspect of this embodiment, the method includes accessing the cavity through the opening to evacuate fluid in the cavity. 
     In another aspect of this embodiment, evacuating fluid from the cavity includes lowering the pressure within the cavity to a sub-atmospheric pressure. 
     In another aspect of this embodiment, the method includes partially closing the opening prior to evacuating fluid from the cavity. 
     In another aspect of this embodiment, the method includes interrupting evacuating fluid by at least a partial closing of the opening in the tissue prior to completing the evacuation of the fluid. 
     In another aspect of this embodiment, evacuating fluid is performed for at least 12 hours and a sub-atmospheric pressure is maintained within the cavity for at least 12 hours. 
     In another aspect of this embodiment, evacuating fluid is performed until at least a portion of the tissue abuts the implant. 
     In another aspect of this embodiment, evacuating fluid is performed until at least one from the group consisting of the tissue surrounding the cavity at least partially heals and the tissue surrounding the cavity secures the tissue with the implant. 
     In another aspect of this embodiment, the method includes closing the opening in the tissue and subsequently reopening the closed opening and further comprising at least one from the group consisting of evacuating any fluid not previously removed and evacuating any fluid that has accumulated after closing the opening. 
     In another aspect of this embodiment, the implant includes a tissue ingrowth promoter on a surface of the implant, and wherein the tissue ingrowth promoter includes a surface with openings. 
     In another aspect of this embodiment, evacuating fluid includes holding tissue of the cavity in abutment with the implant for a duration sufficient for tissue ingrowth into the implant to begin. 
     In another aspect of this embodiment, the implant is one from the group consisting of a battery, pump, controller, wireless power receiver, transcutaneous connector, and any combination thereof. 
     In another aspect of this embodiment, evacuating fluid includes inserting a transcutaneous tube into an opening in the tissue of the patient and evacuating fluid through the transcutaneous tube. 
     In another embodiment, the kid includes an implant including at least one from the group consisting of an electronic device and electromechanical device sized be disposed in a surgically cavity of a patient. A tube is sized to be received within the cavity. A pump is connectable to the tube, the pump being configured generate negative pressure that causes suction in the tube. 
     In another aspect of this embodiment, the implant is one of a battery, implantable pump, controller, wireless power receiver, transcutaneous connector, or any combination thereof. 
     In another aspect of this embodiment, the tube includes a suction catheter with a needle configured to penetrate tissue of the patient. 
     In another aspect of this embodiment, the kit includes a collection canister, the collection canister being connectable with the tube and configured house fluids suctioned through the tube. 
     In yet another embodiment, a method of placing an implant in a patient includes surgically creating a tissue cavity in the patient. An implant consisting of a battery is placed into the tissue cavity. The tissue cavity is partially closed. A transcutaneous tube is inserted into the partially closed tissue cavity. Fluid is evacuated from the cavity through the transcutaneous tube and tissue surrounding the cavity is urged to abut the implant. The pressure is lowered within the cavity to a sub-atmospheric pressure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: 
         FIG. 1  is a diagrammatic perspective view illustrating a kit in accordance with one embodiment of the invention; 
         FIG. 2  is a diagrammatic perspective view illustrating one step of a method according to one embodiment of the invention, employing the kit of  FIG. 1 ; 
         FIG. 3A  is a diagrammatic perspective view depicting the area indicated in  FIG. 2  on an enlarged scale; 
         FIG. 3B  is a diagrammatic, fragmentary sectional view along line  3 B- 3 B in  FIG. 3A ; 
         FIGS. 4A and 4B  are views similar to  FIGS. 3A and 3B  but illustrating another step in the method; and 
         FIG. 5  is a view similar to  FIGS. 3A and 4A  but depicting a later step in the method. 
     
    
    
     DETAILED DESCRIPTION 
     The various devices, kits and associated methods of use of the present invention are intended for removal and otherwise accelerating the removal of fluid cavities within a patient, particularly cavities adjacent to and surrounding devices implanted under a patient&#39;s tissue. The term “implant” as used herein refers to any device or other structure intentionally left within the body following surgery. 
     The term “cavity” as used throughout is intended to refer generally to spaces within the human body. A “cavity” can include either a natural cavity or a surgically created cavity, where a surgically created cavity, or surgical cavity, is one that is either created or develops in conjunction with surgery. Of course, where the term “natural cavity” or “surgical cavity” is used, the meaning corresponding to those terms applies. 
     The term “atmospheric pressure” as used throughout is intended to refer generally to the pressure exerted by the weight of air in the atmosphere of earth. This pressure varies based on local climate conditions, but is generally within several kilopascals of standard atmospheric pressure, 101.3 kPa. The terms “sub-atmospheric pressure” or “negative pressure” as used throughout are intended to refer generally to a pressure in a defined space that is lower than the ambient pressure immediately outside of that space, such as the pressure in a cavity relative to the pressure in the tissue surrounding the cavity. 
     Referring now to  FIG. 1 , a kit according to one embodiment of the invention includes an implant  130  intended and configured for placement inside the body of the patient. In one example, the implant  130  may be a battery for an MCSD. The battery in this example has an outer casing, visible in  FIG. 1 , generally in the form of a smoothed edge rectangular solid. In other embodiments, implant  130  may include an implantable electronic or electromechanical device, such as an electronic controller for a device such as an MCSD, an implantable pump of an MCSD, a wireless power receiver, transcutaneous connectors, or any other device designed for implantation inside the human body, and may have different shapes and sizes. In any of the above variants, the implant  130  can include a tissue ingrowth promoter exposed at one or more outer surfaces of the implant  130 , as schematically indicated at  132  in  FIG. 1 . The tissue ingrowth promoter can include a surface with openings such as a mesh or a knitted surface, a porous or roughened surface or another suitable physical construction which facilitates formation of a strong mechanical bond between tissue in contact with the surface and the implant. The ingrowth promoter may also include chemical or biological materials which tend to promote tissue growth, tissue bonding to the surface, or both. An example of a tissue ingrowth promoter for an implant is described in U.S. Provisional App. No. 62/270,156, hereby incorporated by reference herein in its entirety. 
     The kit also includes a tube  112  structured to access a cavity or cavities in the body where the implant is disposed. The tube  112  includes a first segment  112   a  and a second segment  112   b  having a free end  114 . The free end  114  of the tube has a plurality of perforations  116 . A collection canister  140  is connected between the first segment  112   a  and the second segment  112   b.    
     In some variants, the second segment  112   b  of the tube may be a conventional suction catheter, with the distal end of the catheter constituting the free end  114  of the tube. The free end may include features such as a tapered exterior surface to facilitate introduction of the free end into the body of a patient. The first segment  112   a  may be any conduit which is adapted to resist collapse when the interior of the conduit is subjected to subatmospheric pressure. For example, a braided or thick-walled flexible tube may be used as the first segment. Optionally, the kit can further include a needle and/or a trocar (not shown) for introducing the tube  112 . The size and material of the tube  112  are a matter of design choice and may vary depending on the intended application. The first segment  112   a  of tube  112  has a fitting  113  adapted for connection to a source of suction  110 . The suction source  110  may be a portable vacuum pump, a central vacuum system in a hospital or other healthcare facility, or any other device capable of drawing a fluid from tube  112 . Canister  140  desirably is arranged so that liquid drawn into the canister from second section  112   b  will collect in the canister and will not pass into the second section  112   a.  Canister  140  may be positioned at any location along the tube, but desirably is remote from free end  114 . For example, the canister may be disposed at fitting  113 . Where the suction source  110  can accept liquids, the canister  140  may be omitted entirely. In these variants, tube  112  may be a unitary tube without separate sections. Conventional control elements can be provided for manually or automatically regulating the suction applied through tube  112 . These may include, for example, manually or automatically operated bleed valves for admitting some air into the tube or canister to reduce the amount of suction, and manual or automatic control elements for controlling operation of suction source  110 . 
     The kit discussed above may be pre-assembled and supplied as a unit, for example in a single package. Alternatively, the elements of the kit may be supplied separately and brought together at the point of use. 
     A method according to a further embodiment of the invention can be practiced using the kit  100 . The method commences with the placement of an implant  130 , such as an implantable electronic or electromechanical device, a battery, a pump, a controller, a wireless power receiver, transcutaneous connectors or any combination thereof, into a cavity  24 , as depicted in  FIGS. 3A and 3B . In the depicted embodiment, cavity  24  is a surgically created cavity such as a subcutaneous cavity having a surgically-created opening  26  at the skin surface. As best appreciated with reference to  FIG. 3B , the tissues  22  of the body bounding the cavity  24  may contact the implant  130  at some locations on its surfaces, whereas at other locations the tissue is out of contact with the implant surfaces. This pattern may vary with the shapes and dimensions of the cavity and implanted device. The space within the cavity which is not filled by the implant may contain air. Moreover, bodily fluids such as blood and interstitial fluid may drain from the tissue into the cavity and collect between the tissue and the implant. At this stage of the process, the tissue and fluids within the cavity typically are at atmospheric pressure. 
     A free end  114  of the tube  112  may be positioned in the body of the patient so that it is inside the cavity  24  surrounding the implant  130 . The tube  112  used can be a transcutaneous tube. As shown in  FIG. 4 , placement of the free end  114  of the tube  112  so that it is inside the cavity  24  is accomplished by advancing the free end of the tube through opening  26 . In one configuration, opening  26  is substantially closed by suturing, stapling, application of dressings or other techniques before or after insertion of the tube  112 , so that the portion of the tissue immediately adjacent the opening forms at least a partial seal around the tube. This seal may be enhanced by application of dressings (not shown) over the tube. With the free end  114  of the tube in the cavity as shown in  FIGS. 4A and 4B , and with the fitting  113  connected to suction source  110 , the suction source  110  is actuated to draw fluid from tube  112  and thus create a subatmospheric pressure in the tube  112 . Because part of the tube  112  is inside cavity  24 , see  FIG. 4 , fluid in the cavity  24  is evacuated into the tube  112  drawing fluid toward the suction source  110 . As fluid is evacuated from the cavity  24 , the pressure in the cavity  24  becomes sub-atmospheric. This is in contrast with the surrounding tissue  22 , which is typically at atmospheric pressure. The multiple perforations  116  promote uninterrupted evacuation of fluids from the cavity, and prevent application of excessive suction at any one opening. For example, one or two openings at the end of the tube may be blocked by tissue or other obstructions, preventing the evacuation of fluid from those openings. Because additional openings on the tube remain unobstructed, evacuation may continue unimpeded. 
     The sub-atmospheric pressure caused by the suction through the tube  112  causes tissue walls  23  of the cavity  24  to bear on the surfaces of the implant  130 , as visible in comparing the cavity prior to suction,  FIG. 3B , and the cavity when subject to suction,  FIG. 4B . In  FIG. 4B , the arrows around tissue  22  show clamping effect. Put another way, the pressure differential between atmospheric pressure on the surrounding tissues and the subatmospheric pressure within the cavity causes the cavity to diminish in size and close onto the implant  130  so that the tissue walls  23  abut surfaces of the implant  130  to a greater degree. The subatmospheric pressure in the cavity desirably is maintained by keeping tube  112  held in place in the cavity with the suction source  110  in operation running for a period sufficient to allow appreciable healing, which may be about 12 to 72 hours or more. This effect increases the area of contact between the tissue and the surfaces of the implant, and also holds the tissue abutting the implant in intimate contact with the surfaces of the implant under appreciable contact force. This promotes healing of the tissue in intimate contact with the implant. The pressure can be maintained for a duration sufficient so that tissue ingrowth begins. For example, where the surface of the implant allows ingrowth of tissue or otherwise allows the tissue to adhere to the surface, the tissue may bond to the surface of the implant, become secured to the implant, and/or encapsulate the implant. Removal of fluids such as air and liquids through the tube also aids in maintaining intimate contact between the tissue and the implant. Moreover, if the patient moves during the healing process, the implant may tend to move relative to the surrounding tissue under the influence of gravity or other forces. Such movement can damage the relatively weak partially healed tissues and disrupt partially formed bonds between the tissue and the implant. However, the intimate contact and appreciable contact forces between the tissue and the implant tend to prevent relative movement between the implant and the tissue in contact with the implant. 
     At the end of the evacuation period, the tube  112  is removed and the opening  26  is fully closed, as by suturing  28  shown in  FIG. 5 . With the implant  130  in its intended position and stabilized, the patient is free to engage in a normal range of physical activities with a minimal risk of the implant tearing from the surrounding tissue and/or becoming disengaged from its implanted location in the tissue  22 . Through this procedure, even heavy implants, such as an implantable battery, are stable and secure post-operatively. 
     The methods and kit described above can be varied in many respects. For example, while the pressure differential between the pressure on the surrounding tissue and the pressure within the cavity desirably is maintained continuously during the healing period, it may be maintained intermittently. Also, the pressure differential can be varied during the healing period as, for example, by varying the subatmospheric pressure within the cavity. In the embodiments discussed above, the cavity is a surgically-created cavity. In other embodiments, the cavity is a naturally occurring cavity or a naturally-occurring cavity which has been enlarged surgically. In the variant shown in  FIGS. 3A, 3B and 4A and 4B , the cavity  24  is a single cavity that surrounds the implant  130 , and the pressure differential is applied throughout the entire cavity. In other embodiments, the cavity may include separate parts and the pressure differential may be maintained in less than all of these parts. The tube need not be inserted through the same opening used to place the implant. For example, the opening used to place the implant may be closed and the tube may be inserted into the cavity through a separate opening as, for example, an opening formed by a trocar. Where a natural opening of the body communicates with the cavity, the tube  112  can be placed into the patient through a natural opening of the body. In the embodiments discussed above, the opening used to place the implant is partially closed prior to application of the subatmospheric pressure. However, this opening may be left open and closed at a later time, desirably prior to completion of the evacuation procedure. For example, where the tube is used to cause fluid to be evacuated from the cavity for 48 hours, the opening through which the tube passes into the body can be partially closed prior to the end of the 48 hour period. In a variant, closure of the opening can be performed in stages during evacuation of the cavity. 
     Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims.