Patent Publication Number: US-2021177460-A1

Title: Trocar retractor apparatus and methods for use

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority to U.S. Prov. App. 62/948,050 filed Dec. 13, 2019, which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to medical devices and methods. More particularly, the present invention relates to apparatus and methods for the positioning of trocar devices and tissue regions. 
     BACKGROUND OF THE INVENTION 
     Trocars are typically used for surgical procedures, such as laparoscopic procedures, in order to gain access to interior body lumens through the skin surface. Generally, the trocar includes an obturator which may be blunt or sharpened which may be inserted through a hollow cannula. By inserting the trocar through the skin surface and into the body lumen, such as an abdominal cavity, the obturator may be removed from the cannula leaving an access pathway through the cannula and into the body lumen. Unfortunately, trocars typically do not provide any indication of trocar penetration depth to the user who must estimate the penetration depth during and after penetration of the abdominal wall. 
     Furthermore, trocar insertion can lead to a perforating puncture wound of an underlying organ or structure resulting in a medical complication. For instance, laparoscopic intra-abdominal trocar insertion can lead to injury of the underlying bowels or to hemorrhaging of various blood vessels. This is further complicated by the tendency of the tissue to collapse or depress around the trocar when the trocar is inserted into the tissue. 
     To reduce the incidence of unintentional perforation, surgeons may establish a pneumoperitoneum by insufflating the abdomen with a gas to expand the space between the interior of the abdominal wall and underlying internal organs with the intention of providing a space for a trocar to penetrate through the abdominal wall and above the organs. The pneumoperitoneum is typically established through the use of a Veress needle which is used to penetrate the abdominal cavity and deliver the gas but the needle also has the same potential complications as trocar insertion. 
     Once penetration of the body wall has been attained, the obturator may be removed, leaving a cannula penetrating the body adapted to receive any number of surgical instruments. However, the guide tube may be subject to unintentional or undesirable movements such as changes in penetration depth or accidental withdrawal from the body. 
     Therefore, there exists a need for an insufflation/trocar device which can be inserted safely into a patient body with a reduced risk of underlying tissue injury. There is also a need for devices which allow for the positioning and retraction of tissue regions during procedures without risk of injury or inadvertent movement. 
     SUMMARY OF THE INVENTION 
     One variation of a trocar positioning platform which may also be used for tissue retraction or positioning. The positioning platform may include a substrate having a first side upon which a trocar positioning guide may extend and a second side which is configured to apply a releasable vacuum through one or more suction openings which may be adhered upon a tissue surface for temporary securement. A pump or negative pressure mechanism located remotely from the substrate may be fluidly coupled to the substrate via one or more fluid lines for providing the vacuum force. The one or more suction openings may be distributed over the substrate in a uniform manner, an arbitrary manner, or in any number of predetermined specified configurations. The one or more suction openings may each define a chamber defined by an individual suction assembly. While the number of suction openings may vary from one to a plurality of openings, one variation of the substrate may incorporate, e.g., twenty-one to twenty-five suction openings. 
     The substrate may be formed to have any variety of configurations (e.g., circular, elliptical, rectangular, pentagonal, hexagonal, octagonal, etc.) so long as the substrate is desirably positionable upon a tissue region of interest. While the substrate may be formed in a number of different configurations, the variation shown may be comprised of a first flexible layer and a second flexible layer positioned opposite to the first layer such that a securement layer is formed therebetween and the first and second layers are free to slide relative to one another. The first and second layers may be secured or otherwise sealed to one another around their periphery such that the securement layer between is formed into an air-tight chamber in fluid communication with each of the one or more suction openings. The securement layer may be filled completely or at least partially with a material which restricts the sliding movement between the first and second layers such as a screen, mesh, beads, grooves, channels which are transverse or angled relative to one another, projections on opposed surfaces, etc. or any substance or feature which increases the frictional resistance between the first and second layers. In the event that a mesh layer is used as a securement layer, there is no minimum thickness or porosity that the mesh may have so long as the mesh provides sufficient frictional resistance to movement between the first and second layers when collapsed by the vacuum force. 
     During initial positioning of the substrate against a tissue region, the first and second layers may freely slide relative to one another as well as relative to the securement layer thereby allowing for the substrate to conform against the anatomy of the underlying adhered tissue. Once a vacuum force is applied via a fluidly coupled vacuum line through the substrate, e.g., 600 to 650 mmHg, the one or more suction openings may attach to the underlying tissue due to the negative pressure and the first and second layers may collapse upon or towards one another. The presence of the securement layer may increase the frictional resistance between the contacting inner surfaces of the first and second layers against one another and against the securement layer such that the substrate may become frozen in its reconfigured shape. If the substrate were reconfigured to conform to an anatomy of the underlying tissue or reconfigured into another shape, application of the negative pressure may collapse the first and second layers such that substrate may maintain its configuration while the vacuum is applied. If the substrate were adhered against the underlying tissue in a flattened configuration, application of the negative pressure may collapse the first and second layers such that the flattened configuration is maintained. Once the vacuum force is released or the pressure increased, the first and second layers may release from one another and from the securement layer enabling the substrate to release from the tissue and revert to its flexible shape for removal or attachment to the tissue or to another region of tissue. 
     The substrate may further define one or more channels or openings which may extend from a periphery of the substrate towards the insufflation/trocar positioning guide to further provide for flexibility of the substrate. Moreover, the trocar positioning guide may project from the substrate, e.g., transversely or at an angle relative to the substrate, such that the positioning guide comprises a trocar channel which defines a lumen passing through the substrate to allow for the trocar to pass through and into the underlying tissue. The positioning guide may also have a shoulder which projects radially from a proximal portion of the trocar channel which provides a handle for ease of manipulation and adjustment of the positioning guide and substrate by the user and which also facilitates the insertion of the trocar into the trocar channel. The trocar channel may further define an opening or slit along the channel to provide for angled positioning of the trocar in a controlled manner relative to the substrate and trocar positioning guide. Hence, the width of the opening or slit along the trocar channel may have a dimension which is the same or slightly larger than the diameter of the trocar itself. Moreover, there may be a plurality of interchangeable guides for specific applications or procedures to improve access or retraction such as retraction for tissue positioning, insufflation, trocar placement, or facia closure. 
     In one example of use, the platform may be positioned over a tissue region of interest to be treated and the one or more suction openings may be placed into contact upon the tissue, e.g., skin surface, such that the positioning guide projects away from the skin surface. A vacuum force may be actuated via a pump fluidly coupled via one or more fluid lines and applied through the substrate such that the one or more suction openings create an adhesion force to secure the substrate upon the skin surface. The substrate may be positioned to ensure that the opening of the positioning guide is aligned directly over the portion of the tissue to be pierced by the trocar. 
     With the positioning platform so positioned, the trocar may be advanced through the positioning guide with an insertion force applied to the trocar and towards the tissue region to be entered. Simultaneously, a counterforce may be applied directly to the positioning guide in the opposite direction of the insertion force. With the tissue adhered to the one or more suction openings and with the counterforce applied in the opposing direction of the insertion force from the trocar, the tissue may be maintained in a relatively neutral state as the trocar is inserted through the skin surface and further into the tissue. That is, the tissue may be prevented from dimpling or collapsing further into the body as the trocar is initially inserted and advanced into the tissue. This may further prevent the inadvertent insertion, damage, or nicking of tissue structures during trocar insertion. After the trocar has been inserted into the tissue, the vacuum level may be optionally reduced from an initial level. 
     Another variation of the positioning platform may utilize a substrate formed from any number of biocompatible flexible materials (e.g., polyethylene, polyvinyl, silicone, etc.) which are configured to have an adhesive surface for temporary securement to a skin surface. With the positioning guide extending from the first surface, the second surface may be coated or infused with any number of biocompatible agents or adhesives (e.g., acrylates, cyanoacrylates, silicone, polyurethane, epoxy, etc.) which may temporarily adhere the second surface to the tissue surface. While the substrate may not be adhered via a vacuum force which collapses layers of the substrate to maintain a shape or configuration, the substrate may still be used to retract the tissue once adhered as well as reconfigure the tissue, for example, by manually reconfiguring the tissue region. Furthermore, this variation may also optionally incorporate a pivoting or redirectable positioning guide with the substrate. 
     Yet another variation may utilize a handle secured to the first side of the substrate. This variation may omit a trocar positioning guide and opening such that positioning platform is used as a tissue retractor or manipulator once the substrate is adhered to the tissue surface. The handle may be configured into any number of configurations which allow for the user to manipulate the substrate into various positions. 
     Yet another variation may have a substrate incorporate a handle projecting from a first side of the substrate. The second surface of the substrate may be configured to have, e.g., an adhesive (as described herein), for temporary attachment to a tissue surface. The interior of the substrate may be filled with a particulate material such as beads (made from any variety of materials such as plastics, polymers, etc.) which are free to move relative to one another and contained between the first layer and second layer of the substrate. The beads are freely movable prior to the interior being collapsed by a vacuum force such that the substrate, when placed upon a tissue surface, may conform to the anatomy. Once adhered to the tissue surface in its unconstrained configuration where the beads are freely movable, the substrate may be reconfigured via manipulation of the handle, for instance, to retract the tissue region of interest. The vacuum force may be applied to the interior of the substrate while holding the handle in its reconfigured shape until the layers collapse against one another and upon the contained beads. The beads may collapse against one another increasing the frictional resistance and forcing the substrate to maintain its reconfigured shape and also forcing the adhered tissue to maintain the same reconfigured shape, e.g., remaining in a retracted state. Once the vacuum force is removed and air is allowed to re-enter the interior of substrate, the substrate may relax is shape and allow for the adhered tissue to flatten or return to its initial shape. 
     One variation for an apparatus for positioning an instrument may generally comprise a substrate having a first surface and a second surface opposite to the first surface, an instrument positioning guide projecting from the first surface of the substrate, and one or more suction assemblies positioned along the second surface and in fluid communication with an interior of the substrate, wherein the one or more suction assemblies are attachable to a tissue region via a vacuum force applied through the one or more suction assemblies. The apparatus may have the substrate configured to maintain a predetermined configuration when the vacuum force is applied. 
     One variation for a method of positioning the instrument may generally comprise positioning a second surface of a substrate in proximity to a tissue surface, where the second surface is opposite to a first surface of the substrate, adhering one or more suction assemblies positioned along the second surface to the tissue surface via a vacuum force applied through the one or more suction assemblies, wherein the one or more suction assemblies are in fluid communication with an interior of the substrate, advancing an instrument through or along an instrument positioning guide projecting from the first surface of the substrate and into the tissue surface, and applying a counterforce to the substrate while advancing the instrument into the tissue surface. 
     Another variation for a method of positioning the instrument may generally comprise positioning a second surface of a substrate in proximity to a tissue surface, where the second surface is opposite to a first surface of the substrate, adhering one or more suction assemblies positioned along the second surface to the tissue surface via a vacuum force applied through the one or more suction assemblies, wherein the one or more suction assemblies are in fluid communication with an interior of the substrate, reconfiguring a shape of the substrate while adhering the tissue surface to the one or more suction assemblies such that the tissue surface is reconfigured accordingly, advancing an instrument through or along an instrument positioning guide projecting from the first surface of the substrate and into the tissue surface, and applying a counterforce to the substrate while advancing the instrument into the tissue surface. 
     Yet another apparatus for retracting a tissue region may generally comprise a substrate having a first surface and a second surface opposite to the first surface, one or more suction assemblies positioned along the second surface and in fluid communication with an interior of the substrate, wherein the one or more suction assemblies are attachable to the tissue region via a vacuum force applied through the one or more suction assemblies, and wherein the substrate is configured to maintain a predetermined configuration when the vacuum force is applied. 
     Yet another method of positioning an instrument may generally comprise positioning a second surface of a substrate in proximity to a tissue surface, where the second surface is opposite to a first surface of the substrate, adhering one or more suction assemblies positioned along the second surface to the tissue surface via a vacuum force applied through the one or more suction assemblies, wherein the one or more suction assemblies are in fluid communication with an interior of the substrate, and maintaining a first configuration of the substrate via the vacuum force such that the adhered tissue surface conforms to the first configuration. 
     For all embodiments, it is anticipated that the amount of vacuum required may vary upon the procedure. For example, a higher vacuum level may be required during retraction while a lower vacuum may be required for maintaining position on the tissue, and/or maintaining tissue/trocar orientation. This may be achieved through, e.g., direct adjustment of the vacuum level at the source or a user activated valve which may be integrated into the device itself that may provide variable or preset levels of vacuum. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of one variation of the trocar positioning and retraction platform. 
         FIGS. 2A and 2B  show perspective and side views of the trocar positioning and retraction platform with the trocar angled relative to the platform. 
         FIGS. 3A to 3C  show side views of one example of how the platform may be used to provide a counterforce to the trocar during insertion through tissue. 
         FIG. 3D  shows a side view of the platform assembly in communication with a valve which is controllable to alter the suction force applied through the platform. 
         FIGS. 4A and 4B  show side views of another example of how the platform may be used as a retraction device to hold a tissue region in place. 
         FIGS. 5A and 5B  show various perspective views of yet another variation of the trocar positioning and retraction platform. 
         FIGS. 6A and 6B  show various perspective views of yet another variation of a platform configured for tissue retraction and manipulation. 
         FIG. 7  shows a detail side view of the platform illustrating an example of the securement mechanism. 
         FIGS. 8A and 8B  show various perspective views of yet another variation of a platform configured for tissue retraction and manipulation. 
         FIGS. 9A and 9B  show top and side views of yet another variation of a platform configured for tissue retraction and manipulation. 
         FIG. 9C  shows a side view of the platform of  FIGS. 9A and 9B  illustrating how the platform may be reconfigured to maintain its shape against a tissue region. 
         FIGS. 10A and 10B  show various perspective views of an individual suction mechanism for temporary adherence to a tissue region. 
         FIG. 11  shows a cross-sectional side view of the suction mechanism of  FIGS. 10A and 10B . 
         FIGS. 12A and 12B  show various perspective views of another variation of an individual suction mechanism for temporary adherence to a tissue region. 
         FIG. 13  shows a cross-sectional side view of the suction mechanism of  FIGS. 12A and 12B . 
         FIG. 14  shows a cross-sectional side view of another variation of an individual suction mechanism. 
         FIG. 15  shows a side view of the platform used in combination with a needle. 
         FIG. 16  shows a side view of the platform used in combination with an imaging instrument such as a laparoscope. 
         FIG. 17  shows a perspective view of the platform having an integrated ultrasound transducer to provide imaging while in use with the platform. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In accessing regions within a subject&#39;s body, trocar devices are typically used to provide access for various surgical instruments such as laparoscopic instruments. During the initial insertion of the trocar through the skin and tissue layers, there is risk that the trocar may unintentionally damage underlying tissue. Moreover, once inserted through the skin surface and into the patient body, the trocar and/or instruments may be desirably repositioned or angled relative to the underlying tissue. Additionally, during a surgical procedure, the tissue underlying the skin may be desirably retracted or moved temporarily to facilitate the procedure being performed upon the subject. 
     One variation of a trocar positioning platform which may also be used for tissue retraction or positioning is shown in the perspective view of  FIG. 1 . The positioning platform  10  is shown as substrate  12  having a first side upon which a trocar positioning guide  26  may extend and a second side which is configured to apply a releasable vacuum through one or more suction openings  20  which may be adhered upon a tissue surface for temporary securement. A pump or negative pressure mechanism located remotely from the substrate  12  may be fluidly coupled to the substrate  12  via one or more fluid lines for providing the vacuum force. The one or more suction openings  20  may be distributed over the substrate  12  in a uniform manner, an arbitrary manner, or in any number of predetermined specified configurations. The one or more suction openings  20  may each define a chamber defined by an individual suction assembly  22 . While the number of suction openings  20  may vary from one to a plurality of openings, one variation of the substrate  12  may incorporate, e.g., twenty-one to twenty-five suction openings. 
     The substrate  12  may be formed to have any variety of configurations (e.g., circular, elliptical, rectangular, pentagonal, hexagonal, octagonal, etc.) so long as the substrate  12  is desirably positionable upon a tissue region of interest. While the substrate  12  may be formed in a number of different configurations, the variation shown may be comprised of a first flexible layer  14  and a second flexible layer  16  positioned opposite to the first layer  14  such that a securement layer  18  is formed therebetween and the first and second layers  14 ,  16  are free to slide relative to one another. The first and second layers  14 ,  16  may be secured or otherwise sealed to one another around their periphery such that the securement layer  18  between is formed into an air-tight chamber in fluid communication with each of the one or more suction openings  20 . The securement layer  18  may be filled completely or at least partially with a material which restricts the sliding movement between the first and second layers  14 ,  16  such as a screen, mesh, beads, grooves, channels which are transverse or angled relative to one another, projections on opposed surfaces, etc. or any substance or feature which increases the frictional resistance between the first and second layers  14 ,  16 . In the event that a mesh layer is used as a securement layer  18 , there is no minimum thickness or porosity that the mesh may have so long as the mesh provides sufficient frictional resistance to movement between the first and second layers  14 ,  16  when collapsed by the vacuum force. 
     During initial positioning of the substrate against a tissue region, the first and second layers  14 ,  16  may freely slide relative to one another as well as relative to the securement layer  18  thereby allowing for the substrate  12  to conform against the anatomy of the underlying adhered tissue. Once a vacuum force is applied via a fluidly coupled vacuum line through the substrate  12 , e.g., 600 to 650 mmHg, the one or more suction openings  20  may attach to the underlying tissue due to the negative pressure and the first and second layers  14 ,  16  may collapse upon or towards one another. The presence of the securement layer  18  may increase the frictional resistance between the contacting inner surfaces of the first and second layers  14 ,  16  against one another and against the securement layer  18  such that the substrate  12  may become frozen in its reconfigured shape. If the substrate  12  were reconfigured to conform to an anatomy of the underlying tissue or reconfigured into another shape, application of the negative pressure may collapse the first and second layers  14 ,  16  such that substrate  12  may maintain its configuration while the vacuum is applied. If the substrate  12  were adhered against the underlying tissue in a flattened configuration, application of the negative pressure may collapse the first and second layers  14 ,  16  such that the flattened configuration is maintained. Once the vacuum force is released or the pressure increased, the first and second layers  14 ,  16  may release from one another and from the securement layer  18  enabling the substrate  12  to release from the tissue and revert to its flexible shape for removal or attachment to the tissue or to another region of tissue. 
     The substrate  12  may further define one or more channels or openings  24  which may extend from a periphery of the substrate  12  towards the trocar positioning guide  26  to further provide for flexibility of the substrate  12 . Moreover, the trocar positioning guide  26  may project from the substrate  12 , e.g., transversely or at an angle relative to the substrate  12 , such that the positioning guide  26  comprises a trocar channel  30  which defines a lumen  32  passing through the substrate  12  to allow for the trocar  36  to pass through and into the underlying tissue. The trocar  36  may be seen extending through the trocar channel  30  such that the trocar distal tip  38  has been pushed through past the substrate  12  and into the underlying tissue. The positioning guide  26  may also have a shoulder  28  which projects radially from a proximal portion of the trocar channel  30  which provides a handle for ease of manipulation and adjustment of the positioning guide  26  and substrate  12  by the user and which also facilitates the insertion of the trocar  36  into the trocar channel  30 . The trocar channel  30  may further define an opening or slit  34  along the channel  30  to provide for angled positioning of the trocar  36  in a controlled manner relative to the substrate  12  and trocar positioning guide  26 . Hence, the width of the opening or slit  34  along the trocar channel  30  may have a dimension which is the same or slightly larger than the diameter of the trocar  36  itself. 
       FIGS. 2A and 2B  show perspective and side views of the substrate  12  and the trocar  36  angled relative to the substrate  12 . With the substrate  12  adhered against the tissue surface, the trocar  36  may be inserted at an angle relative to the substrate  12  and/or tissue surface or the trocar  36  may be angled after insertion such that the body of the trocar  36  is positioned within or along the opening or slit  34  defined along the channel  30 . In either case, the trocar  36  may be positioned at an angle θ such that a longitudinal axis of the trocar  36  is angled relative to a longitudinal axis of the positioning guide  26 . The angle θ may range anywhere from, e.g., 0 degrees to close to 90 degrees, depending upon the desired positioning of the trocar  36 . While the positioning guide  26  is illustrated as having a channel  30 , other variations of the positioning guide  26  may include other pivoting mechanisms, such as a ball pivot, etc. 
     One example is illustrated in the side views of  FIGS. 3A to 3C  showing how the trocar positioning platform  10  may be used for tissue retraction during insertion of a trocar  36  into a tissue region of interest. As shown in  FIG. 3A , the platform  10  may be positioned over a tissue region of interest to be treated and the one or more suction openings  20  may be placed into contact upon the tissue, e.g., skin surface S, such that the positioning guide  26  projects away from the skin surface S, as shown. A vacuum force may be actuated via pump  41  fluidly coupled via one or more fluid lines  43  and applied through the substrate  12  such that the one or more suction openings  20  create an adhesion force  40  to secure the substrate  12  upon the skin surface S. The substrate  12  may be positioned to ensure that the opening of the positioning guide  26  is aligned directly over the portion of the tissue to be pierced by the trocar  36 . 
     With the positioning platform  10  so positioned, the trocar  36  may be advanced through the positioning guide  26  with an insertion force  44  applied to the trocar  36  and towards the tissue region to be entered. Simultaneously, a counterforce  42  may be applied directly to the positioning guide  26  in the opposite direction of the insertion force  44 , as shown in  FIG. 3B . With the tissue adhered to the one or more suction openings  20  and with the counterforce  42  applied in the opposing direction of the insertion force  44  from the trocar  36 , the tissue may be maintained in a relatively neutral state as the trocar  36  is inserted through the skin surface S and further into the tissue, as shown in  FIG. 3C . That is, the tissue may be prevented from dimpling or collapsing further into the body as the trocar  36  is initially inserted and advanced into the tissue. This may further prevent the inadvertent insertion, damage, or nicking of tissue structures during trocar  36  insertion. After the trocar  36  has been inserted into the tissue, the vacuum level may be optionally reduced from an initial level. 
     As the trocar  36  is inserted into and through the tissue, the relatively large diameter of the trocar  36  can “tent” the tissue inwardly into the patient when the point of the trocar  36  is pressed through the abdomen. The amount of tenting may dramatically increase the force required to place the trocar  36  but because the practitioner not only lifts the tissue (to also help move any internal organs out of the way) tenting of the tissue is also minimized thus requiring less force to insert the trocar  36  and also reducing the possibility of over inserting the trocar  36  into the patient body as the trocar  36  breaks into the peritoneum. 
     In the event that a pivoting positioning guide (as described herein) is utilized with the substrate  12 , the positioning guide may be reoriented before, during, or after insertion and/or advancement of the trocar  36  into the tissue to redirect the trocar insertion into the tissue. 
     In one variation, the trocar  36  may be advanced using one hand of the user while the positioning guide  26  is retracted by the other hand of the user. In other variations, both the insertion and advancement of the trocar  36  as well as the retraction of the positioning guide  26  may be performed by a single hand of the user. In yet other variations, both the insertion of the trocar  36  and the retraction of the positioning guide  26  may be performed by different users. 
     The tissue surface S is shown in the example as remaining in a relatively flattened state during trocar  36  insertion and advancement. However, in other variations, the adhered tissue may be retracted by the positioning platform  10  and conformed by substrate  12  into a different configuration, such as a retracted configuration, which may then be maintained by the substrate  12  locking its configuration. With the altered tissue configuration, the same steps of trocar  36  insertion and advancement with retraction of the positioning guide  26  may be performed, as described. 
     While the adhesion force  40  created by pump  41  to secure the platform  10  to the skin surface S may be maintained at a constant level prior to, during, and/or after a procedure, the adhesion force may be optionally varied as well.  FIG. 3D  illustrates a side view of the positioning guide  26  with one or more fluid lines  43  fluidly coupling the platform  10  to the pump  41 , as previously described, but this variation may incorporate a valve  45 , such as a check valve or variably controllable valve, along the one or more fluid lines  43  to control the level of suction force upon the skin surface S. The valve  45  may be manually controlled or the valve  45  may be optionally controlled by a controller  47  in communication with valve  45  and pump  41 . The controller  47  may be programmed, for instance, to open and/or close the valve  45  at predetermined pressure levels or the valve  45  may be programmed to open and/or close at predetermined points of a procedure or when actuated by the user. 
     In yet another variation, a maximum first vacuum level may be applied during insertion of the trocar or other instrument such that the platform  10  provides for an optimal lifting force of the tissue. Once the insertion through the tissue has been completed, the vacuum force applied by platform  10  may be automatically adjusted down to a lower second vacuum level which may also prevent the formation of any bruises or hematomas which may result from the platform  10  being adhered to the skin surface. 
     An example is illustrated in the side views of  FIGS. 4A and 4B  which show the positioning platform  10  placed against the tissue surface and adhered to the tissue while in a first configuration. In this variation, the positioning platform  10  may have a flattened configuration relative to the skin surface. With the one or more suction openings  20  adhered to the tissue via the adhesion force  40 , the positioning guide  26  and/or substrate  12  may be retracted or moved from its initial position such that the positioning platform  10  conforms into a second configuration  50  causing the underlying adhered tissue to conform accordingly, as shown in  FIG. 4B . The substrate  12  may be conformed, as described herein, to maintain this second configuration  50  to hold or maintain the adhered skin in a retracted configuration. The positioning platform  10  may be used accordingly, e.g., as an external tissue retractor, for any number of procedures such as for breast retraction. 
     Another variation of the positioning platform is illustrated in the perspective views of  FIGS. 5A and 5B . In this variation, the substrate  60  may be formed from any number of biocompatible flexible materials (e.g., polyethylene, polyvinyl, silicone, etc.) which are configured to have an adhesive surface  62  for temporary securement to a skin surface. With the positioning guide  26  extending from the first surface, the second surface  62  may be coated or infused with any number of biocompatible agents or adhesives (e.g., acrylates, cyanoacrylates, silicone, polyurethane, epoxy, etc.) which may temporarily adhere the second surface  62  to the tissue surface. While the substrate  60  may not be adhered via a vacuum force which collapses layers of the substrate to maintain a shape or configuration, the substrate  60  may still be used to retract the tissue once adhered as well as reconfigure the tissue, for example, by manually reconfiguring the tissue region. Furthermore, this variation may also optionally incorporate a pivoting or redirectable positioning guide  26  with the substrate  60 . 
     Yet another variation is shown in the perspective views of  FIGS. 6A and 6B  which illustrate a substrate  70  having the one or more suction openings  20  along a second side of the substrate  70  and a handle  74  secured to the first side of the substrate  70 . A vacuum tube attachment  72  is illustrated as being fluidly coupled along the first side of the substrate  70 . This variation may omit a trocar positioning guide  26  and opening such that positioning platform is used as a tissue retractor or manipulator once the substrate  70  is adhered to the tissue surface. The handle  74  may be configured into any number of configurations which allow for the user to manipulate the substrate  70  into various positions. 
       FIG. 7  shows a partial cross-sectional side view of the variation of  FIGS. 6A  and  6 B to illustrate how the first layer  76  and the second layer  78  may be sealed to one another, e.g., around their periphery, to form the securement layer  80  within. As described above, the securement layer  80  may contain any number of substances or features which are designed to increase a frictional resistance between the first and second layers  76 ,  78  when the layers are collapsed against one another. Each of the one or more suction openings  20  may be seen as extending from the second surface and are each in fluid communication with the securement layer  80  between the first and second layers  76 ,  78 . 
       FIGS. 8A and 8B  show perspective views of yet another variation of a substrate  90  which may be similar to the substrate  60  described herein. This variation may incorporate the handle  74  with the substrate  90  so that the positioning platform may be utilized, e.g., as a tissue retractor or manipulator, once adhered to the tissue surface. 
     Yet another variation is shown in the top and side views of  FIGS. 9A to 9C  which show a positioning platform configured for tissue retraction and/or manipulation. The substrate  100  in this variation may incorporate a handle  102  projecting from a first side of the substrate  100 . A vacuum tube attachment  104  is also shown projecting from the first side and which is in fluid communication with the interior of the substrate, as shown in the top view of  FIG. 9A . The second surface of the substrate  100  may be configured to have, e.g., an adhesive (as described herein), for temporary attachment to a tissue surface. The side view of  FIG. 9B  shows a detail cross-sectional view of an interior of the substrate  100  which may be filled with a particulate material such as beads  106  (made from any variety of materials such as plastics, polymers, etc.) which are free to move relative to one another and contained between the first layer  101  and second layer  103  of the substrate  100 . As illustrated, the beads  106  are shown to be freely movable prior to the interior being collapsed by a vacuum force such that the substrate  100 , when placed upon a tissue surface, may conform to the anatomy. Once adhered to the tissue surface in its unconstrained configuration where the beads  106  are freely movable, the substrate  100  may be reconfigured via manipulation of the handle  102 , for instance, to retract the tissue region of interest. The vacuum force may be applied to the interior of the substrate  100 ′ while holding the handle  102  in its reconfigured shape until the layers  101 ,  103  to collapse against one another and upon the contained beads  106 , as shown in  FIG. 9C . The beads  106  may collapse against one another increasing the frictional resistance and forcing the substrate  100 ′ to maintain its reconfigured shape and also forcing the adhered tissue to maintain the same reconfigured shape, e.g., remaining in a retracted state. Once the vacuum force is removed and air is allowed to re-enter the interior of substrate  100 , the substrate  100  may relax is shape and allow for the adhered tissue to flatten or return to its initial shape. 
     Turning now to the structure of the individual suction assembly  22 ,  FIGS. 10A and 10B  show various perspective views of one variation. The suction assembly  22  may be formed to have a suction housing  110  which projects to form a suction chamber  112  for placement against the surface of the tissue to be adhered. The suction housing  110  may define any number of cross-sectional shapes suitable for forming the suction chamber  112  (e.g., circular, elliptical, rectangular, polygonal, etc.) and may project distally from a lower housing  114  having a lower shoulder  116  which projects radially to form a lower periphery of the lower housing  114 . An upper housing  118  may be attached to the lower housing  114  and may similarly have an upper shoulder  120  which projects radially to form an upper periphery of the upper housing  118 . A substrate attachment portion  122  may be formed between the lower shoulder  116  and the upper shoulder  120  for attachment to the first and second layers of the substrate. Additionally, one or more fluid channels  124  may be defined around the periphery of the substrate attachment portion  122  for providing fluid communication with the interior of the securement layer  18 . While the lower housing  114  and upper housing  118  are illustrated as having a circularly-shaped form annularly relative to the suction housing  110 , the lower housing  114  and upper housing  118  may be formed to have other shapes or configurations. 
       FIG. 11  illustrates a cross-sectional side view of a suction assembly attached to a substrate. As shown, the first layer  14  may be attached about the upper shoulder  120  forming a fluid-tight seal and the second layer  16  may be attached about the lower shoulder  116  also forming a fluid-tight seal while the one or more fluid channels  124  defined about the periphery of the substrate attachment portion  122  remain in fluid communication with the interior of the securement layer  18 . A housing chamber  134  may be formed between a floor  130  of the lower housing  114  and the upper housing  118  with a valve  136 , e.g., umbrella valve, which may be biased towards the floor  130  to maintain the valve  136  in a closed configuration against the floor  130 . A retaining member  138  projecting from the valve  136  may extend through an opening  132  defined through the floor  130  and partially into the suction chamber  112 . The retaining member  138  may be configured to include a widened, retaining portion which allows for the valve  136  to move between an open and closed configuration until the widened portion abuts against the opening  132  to limit the amount that the valve  136  may open. 
     During use when the vacuum force is applied to the substrate, the air or gas within the securement layer  18  and also within the housing chamber  134  may evacuate urging the valve  136  into an open configuration where the valve  136  extends into the interior of the housing chamber  134  while limited in travel by the widened, retaining portion of the retaining member  138 . With the valve  136  thus opened, the air or gas within the suction chamber  112  may also evacuate via one or more openings defined through the floor  130  and into and through the housing chamber  134  and out through one or more fluid channels  124  causing the suction housing  110  to adhere to the underlying contacted tissue surface due to the negative pressure created within the suction chamber  112 . As the valve  136  may be optionally biased to close against the floor  130 , once the suction pressure has reached an equilibrium between the housing chamber  134  and suction chamber  112  (or when the suction pressure has dropped below the biased closing force of the valve  136 ), the valve  136  may close against the floor  130  to seal the suction chamber  112  from the housing chamber  134 . In this manner, the suction securement between the suction housing  110  and the adhered tissue surface may be maintained individually between each of the suction assemblies  22  and tissue surface. This may be especially helpful in the event that vacuum pressure is lost within the securement layer  18  during a procedure as each of the individual suction assemblies  22  may maintain suction adherence to the tissue surface independently of one another. 
     Another variation of the suction assembly  140  is shown in the various perspective views of  FIGS. 12A and 12B  which illustrate a suction housing  142  defining a suction chamber  144  similarly formed from a lower housing  146  having a lower shoulder  148 . An upper housing  150  having an upper shoulder  152  may attach to the lower housing  146  and form a substrate attachment portion  154  about a periphery of the housing assembly. Also, one or more fluid channels  156  may be defined about the periphery of the substrate attachment portion  154 . 
     As shown in the cross-sectional side view of  FIG. 13 , the manner in which the valve  166  is designed and positioned within the housing chamber  164  may allow for the height between the lower shoulder  148  and upper shoulder  152  to be reduced relative to previous embodiments while still allowing for fluid communication through the one or more fluid channels  156  with the securement layer  18 . This reduced height may also allow for a substrate which is relatively thinner. The valve  166  may be biased to remain in a closed configured where an outer sealing surface  170  of sealing member  168  is urged against an opening  162  defined over the floor  160  of the lower housing  146 . The sealing member  168  may be configured in a conical shape projecting from the valve body such that when the vacuum is applied to the substrate, the valve  166  may be urged into its open configuration such that the sealing surface  170  is lifted away from the opening  162  allowing for the negative pressure within the suction chamber  144  to adhere the underlying tissue surface to the suction housing  142 . As described above, when the suction pressure has reached an equilibrium between the housing chamber  164  and suction chamber  144  (or when the suction pressure has dropped below the biased closing force of the valve  166 ), the valve  166  may close against the floor  160  to seal the suction chamber  144  from the housing chamber  164 . This allows for the individual suction assembly to adhere to the tissue surface. 
     As previously described, the vacuum tube attachment may be coupled to the substrate for providing fluid communication between a pump and the securement layer of the substrate and suction assemblies. While the vacuum tube attachment may be coupled at any location over the substrate, the attachment may also be coupled to one of the suction assemblies.  FIG. 14  shows a cross-sectional side view of one variation where a vacuum tube  182  having a lumen  184  defined through the length of the tube  182  may be attached directly to at least one of the suction assemblies. A distal end of the tube  182  may be attached to the housing of the suction assembly such that the lumen  184  may be fluidly coupled directly to the housing chamber  164 . A proximal end of the tube  182  may be fluidly attached to a fluid line for communication with a pump such that when the pump is actuated, the vacuum force may be applied through the lumen  184  and the attached suction assembly. As the suction assembly is fluidly coupled with the securement layer and the other suction assemblies, the vacuum force may applied to the entire substrate and suction assemblies accordingly. 
     Turning now to other uses or implementations of the positioning platform  10 , various laparoscopic procedures may be facilitated using any of the platform embodiments described herein. One particular procedure may involve the use of the platform for establishing a pneumoperitoneal cavity in a patient via insufflation in preparation for an abdominal (or other cavity) procedure. The practitioner typically identifies a location along the patient body, such as the abdomen, where an instrument such as a Veress needle may be penetrated through the skin until the tip reaches just inside the peritoneum. The practitioner oftentimes inserts the needle blindly into the patient body which may result in an unintended injury. For instance, if a portion of the bowel is adhered to the inner wall of the peritoneum, the needle may be inserted over the adhesion resulting in the bowel being pierced or nicked. 
     Once the needle has been suitably positioned within the patient body, the cavity is then inflated through the needle and a primary trocar may be inserted, also blindly, into the peritoneum. For patients with adhesions, a similar complication as with the needle insertion can occur with the trocar. Another instrument such as a laparopscopic camera may then be inserted into the peritoneum through the primary trocar, for instance, to facilitate the insertion of additional trocars into the patient under direct vision to reduce the risk of internal damage. 
     With the positioning platform  10  adhered to the skin surface S, the platform  10  may be used to lift the region of tissue of tissue where the needle and/or trocar will be inserted to facilitate the separation of any bowel tissue from the interior of the abdominal wall. Lifting of the tissue area may also help the practitioner to assess for the existence of any adhesions prior to the insertion of the needle and/or trocar. 
     An example is shown in the side view of  FIG. 15  which illustrates the application of the platform  10  against the skin surface S which may be lifted away from the patient in order to lift the adhered tissue and provide feedback as to the presence of any adhesions. Once the assessment has been made, the needle  190  may be inserted through positioning guide  26  until the piercing tip  192  of the needle or blunt tip  194  has been inserted past the interior tissue wall away from adhesions. Alternatively, the platform  10  may be removed from the tissue region once the assessment has been completed with the platform  10  and the needle  190  may be inserted directly into and through the skin surface S. 
     In other variations, the platform  10  may be utilized directly with an imaging instrument such as a laparoscope  200 , as shown in the side view of  FIG. 16 . After trocar insertion through the skin surface S, the trocar may be removed leaving the cannula sleeve  202  in place through the tissue region. The laparoscope  200  may be inserted, e.g., directly through the cannula sleeve  202  in order to provide for direct visualization within the body cavity. 
     In yet another variation, the platform  10  may be used in combination with an imaging instrument such as an ultrasound transducer  212  which may be in communication with either a controller  47  (as previously described) or a separate ultrasound controller  214 , as shown in the perspective view of  FIG. 17 . The ultrasound transducer  212  may be used to determine, e.g., whether any adhesions are present underlying the skin surface prior to the application of the platform  10  against the tissue surface. The ultrasound transducer  212  may be initially applied to the skin and then removed to allow for the use of the platform  10  but in other variations, the ultrasound transducer  212  may be incorporated directly with the platform  10 . One variation is shown where one or more openings  210  may be formed through the platform  10  next to positioning guide  26  where an ultrasound transducer  212  may be integrated with the platform  10  at one of the openings  210 . The transducer  212  may be used to provide for real time imaging of the tissue region directly below the platform  10  prior to and during trocar insertion while the platform  10  is adhered directly to the skin surface S. 
     When the trocar is removed, gas from the pneumoperitoneum can be evacuated through the opening or may leak through the opening. In order to maintain a fluid-tight seal through the opening in the tissue or through the trocar to maintain the pneumoperitoneum, a seal or stopper may be inserted to cover the trocar opening or directly over the tissue opening. At the end of the procedure, openings (e.g., larger than 12 mm) through the abdominal wall may be sutured closed. 
     The applications of the disclosed invention discussed above are not limited to certain treatments or regions of the body but may include any number of other treatments and areas of the body. Modification of the above-described methods and devices for carrying out the invention, and variations of aspects of the invention that are obvious to those of skill in the arts are intended to be within the scope of this disclosure. Moreover, various combinations of aspects between examples are also contemplated and are considered to be within the scope of this disclosure as well.