Patent Publication Number: US-2004049154-A1

Title: Inflatable device for treating tissue

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
     [0001] This application is related to and claims priority to U.S. Utility patent application Ser. No. 09/971,015, filed Oct. 4, 2001, entitled EXPANDABLE DEVICE FOR THERMAL THERAPY, which claims priority to U.S. Provisional Patent Application Serial No. 60/238,314, filed Oct. 5, 2000, entitled SYSTEMS AND METHODS FOR CONTROLLING TEMPERATURE OF BRAIN TISSUE, the entireties of which are incorporated herein by reference. 
    
    
     
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002] n/a  
       FIELD OF THE INVENTION  
       [0003] The present invention relates to a device and method for controlling brain tissue temperature, and in particular, to a device and method for sub-cranial temperature control of brain tissue through the use of expandable elements, such as balloons  
       BACKGROUND OF THE INVENTION  
       [0004] The benefits of the application or removal of thermal energy to or from a localized portion of a tissue area to apply or remove thermal energy is well known in the art. Balloons are commonly used to contact a tissue. It is desirable to have a delivery device that facilitates the introduction of thermal energy to a tissue region. While it is known to use balloons to contact tissue surfaces along the length of a catheter that is inserted into a vessel, a need arises for a device to apply localized thermal energy in alternate treatment scenarios. For example, as is known in the art, it is desirable to be able to apply or remove thermal energy to or from the extreme end of a catheter.  
       [0005] It is also desirable to avoid creating unnatural openings in a human body. However, when a medical need mandates creating an opening, making as small an opening as possible is advantageous. The need to keep openings to a minimum is particularly applicable when dealing with openings in a human skull. However, a device is needed to apply or remove thermal energy to or from a tissue area with a larger surface area than the opening through which the catheter is inserted.  
       [0006] Problems of uniform thermal distribution also arise with known devices. When a thermally transmissive fluid is infused into a space, the distribution of thermal energy is governed by the function of thermal convection. As such, in many situations thermal energy is not evenly distributed throughout the space. Therefore, it is desirable to provide a device which evenly distributes or removes thermal energy from tissue.  
       SUMMARY OF THE INVENTION  
       [0007] According to an aspect of the present invention, an expandable device for thermally affecting tissue is provided in which a fluid conduit having a longitudinal axis is in fluid communication with an expandable element. The expandable element has a wall defining an inner volume. The wall has a tissue contact which is non-coaxial with the longitudinal axis of the fluid conduit. The tissue contact region is operable to have a first contact surface area and a second contact surface area. The second contact surface area is larger than the first contact surface area.  
       [0008] According to another aspect of the present invention, another expandable element for thermally affecting tissue is provided in which a port has a longitudinal axis and is in fluid communication with an expandable element. A wall defines an inner volume and the wall has a tissue contact region. The tissue contact region is non-coaxial with the longitudinal axis of the port. The tissue contact region is operable to have a first contact surface area and a second contact surface area. The second contact surface area is larger than the first contact surface area.  
       [0009] According to yet another aspect of the present invention, a method of using an expandable element to affect a thermal energy change in tissue of a patent&#39;s body is provided in which an opening is created in the patient&#39;s body. The expandable element is in fluid communication with a fluid conduit and has a tissue contact region that is non-coaxial with a longitudinal axis of the fluid conduit. The tissue contact region is operable to have a first contact surface area and a second contact surface area which is larger than the first contact surface area. At least a portion of the expandable element is inserted into the opening, having a first contact surface area, and into a region between an outer barrier of the patent&#39;s body and the tissue. The tissue contact region is then operated to the second contact surface area and infused with a thermally transmissive fluid, thereby affecting a thermal change in the tissue.  
       [0010] According to yet another aspect of the present invention, the expandable element is operable connected to a housing. The housing includes a first end region and a second end region, the second end region containing a fluid inlet and a fluid outlet, and the housing being securable to a boney structure of the patient. The expandable element is coupled to the housing first end region such that the inner volume is in fluid communication with the fluid inlet and the fluid outlet.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0011] 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:  
     [0012]FIG. 1 is a perspective view of an exemplary embodiment of a device constructed in accordance with the principles of the present invention;  
     [0013]FIG. 2 is a top view of an expandable element of the invention;  
     [0014]FIG. 3 illustrates a side view of the device shown in FIG. 1, in a bundled state;  
     [0015]FIG. 4 is a side view of the device shown in FIG. 1, in a deployed state;  
     [0016]FIG. 5 shows a perspective view of an alternate embodiment of an expandable portion of the device constructed in accordance with the principles of the present invention;  
     [0017]FIG. 6 is a sectional view of the device taken along section  6 - 6  in FIG. 1;  
     [0018]FIG. 7 is an alternate sectional view of the device taken along section  6 - 6  in FIG. 1;  
     [0019]FIG. 8 is another alternate sectional view of the device taken along section  6 - 6  in FIG. 1;  
     [0020]FIG. 9 is still another alternate sectional view of the device taken along section  6 - 6  in FIG. 1;  
     [0021]FIG. 10 shows a cut-away perspective view of the device in a deployed state;  
     [0022]FIG. 11 is a planar view of a fluid distribution element of a device constructed in accordance with the principles of the present invention;  
     [0023]FIG. 12 is an alternate planar view of a fluid distribution element of a device constructed in accordance with the principles of the present invention;  
     [0024]FIG. 13 shows a cut-away end view of a device in a deployed state constructed in accordance with the principles of the present invention;  
     [0025]FIG. 14 is a sectional view of an exemplary interface region of the device taken along section  14 - 14  in FIG. 1;  
     [0026]FIG. 15 is a perspective view of a junction of a device constructed in accordance with the principles of the present invention;  
     [0027]FIG. 16 is a cross-sectional view of an exemplary interface region of the device taken along section  14 - 14  in FIG. 1;  
     [0028]FIG. 17 is a cut-away, perspective view of an alternate arrangement of a junction of a device constructed in accordance with the principles of the present invention;  
     [0029]FIG. 18 is a cut-away, perspective view of still another alternate arrangement of a junction of a device constructed in accordance with the principles of the present invention;  
     [0030]FIG. 19 is a sectional view taken along section  19 - 19  in FIG. 5;  
     [0031]FIG. 20 is a perspective view of an alternate embodiment of a device constructed in accordance with the principles of the present invention;  
     [0032]FIG. 21 is a side view of an alternate fluid distribution element of a device constructed in accordance with the principles of the present invention;  
     [0033]FIG. 22 is an overhead view of the fluid distribution element shown in FIG. 21;  
     [0034]FIG. 23 is an bottom view of the fluid distribution element shown in FIG. 21;  
     [0035]FIG. 24 is a perspective view of an exemplary system in a bundled state constructed in accordance with the principles of the present invention;  
     [0036]FIG. 25 is a perspective view of an exemplary system in a deployed state constructed in accordance with the principles of the present invention;  
     [0037]FIG. 26 is a perspective view of an alternative embodiment of the device of the present invention including a securable housing;  
     [0038]FIG. 27 is a side view of the alternative embodiment of the present invention; and  
     [0039]FIG. 28 is a perspective view of the alternative embodiment of the present invention in a deployed state. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0040] The present invention provides a device having an expandable surface area for the application or removal of thermal energy to/from a selected site. The present invention also provides a device that can be inserted through an opening in a patient&#39;s body and expanded or deployed to cover a greater surface area than a device whose contact surface area is less than or equal to the size of the opening or which occupies the surface area along a small portion of the length of the device. Further provided is a feature which deploys the expandable portion of the device and supplies the expandable portion with material which imparts or removes thermal energy from the selected tissue site.  
     [0041] Referring now to the drawing figures in which like reference designators refer to like elements, there is shown FIG. 1 a perspective view of an exemplary embodiment of a device constructed in accordance with the principles of the present invention and designated generally as device  10 . The device  10  includes a body  12  having a proximal end  14 , a distal end  16  opposite the proximal end  14  and an expandable element  18  such as a balloon coupled to the distal end  16  of the body  12 . The expandable element  18  is provided with a physical structure that allows the expandable element  18  to be inserted through a small opening  20  and then deployed, thereby expanding a tissue contact surface area  22 . When deployed, the tissue contact surface area  22  has a surface area greater than when the expandable element  18  is not deployed, with which to contact a tissue  24 . Further, expandable element  18  is arranged to be deployable within a region  25  between an outer barrier  27  and the tissue  24  without causing damage to tissue  24 . An example of region  25  is found between the skull and the dura mater in a human. The tissue contact surface area  22  can have a shape ranging from substantially flat to concave or being flexible enough to conform to natural contours on the tissue surface.  
     [0042] In an alternate insertion procedure, the expandable element can be placed against the dura mater which has been exposed by a craniotomy. An opening is then made in the boney plate, removed during the craniotomy, for the body  12  of the device to pass through. When the boney plate is reattached to the skull, the expandable element remains within the epidural space, while the body  12  passes to the exterior of the skull. When removal of the expandable element is desired, the expandable element can then be “deflated” and removed through the opening in the boney plate. Additionally, many different ways to reach the boney material of a skull are contemplated. For example, the skin that lies directly adjacent the location of the desired opening in the boney material can be cut or removed to allow the device to transverse the skin layer. Alternatively, an incision can be made a distance from the opening in the boney plate and the device “tunneled” under the skin to the skull insertion point.  
     [0043] In an exemplary embodiment of the invention, the expandable portion of the device is provided by a bundled expandable element  18 . The bundled expandable element  18  defines a diameter small enough to fit into a standard sized burr hole in a skull, such as 5 mm, 8 mm, 11 mm and 14 mm diameters. The expandable element  18  is then infused with chilled or heated fluid to expand its shape to a deployed state, the expansion causing contact with the tissue to be treated. The fluid can thereby impart a thermal change to the expandable element which in turn imparts a thermal change to the contacted tissue. Furthermore, the temperature of the fluid can be regulated such that a constant temperature can be maintained or specific cooling/heating regimens provided. The term fluid as used herein refers to a substance in a liquid state, a gaseous state, a transition state or a combination thereof.  
     [0044] It is further contemplated that a device in accordance with the principles of the present invention can be used to create an epidural pocket between the dura mater and the inner skull. For example, once the device is inserted into the opening and deployed, it will separate the dura from the inner skull, thereby creating an area for the device  10  to reside during a treatment. Alternatively, a discrete device or an attachment to the device  10  can be used to create the epidural pocket before deployment of the device  10 . Further, it is contemplated that a hemostasis-inducing coating can be applied to the expandable element  18  to reduce bleeding that can occur during operation of the device  10 . Alternatively, the device  10  can be equipped with a method for cauterizing the dura as the epidural pocket is created, thereby reducing bleeding that may occur.  
     [0045]FIG. 1 shows the expandable element  18  in association with a flexible body  12 , however, it will be readily understood by one of ordinary skill in the art that any number of alternate structures may be used, for example any shaped expandable balloon element or multi-balloon elements having various sizes, shapes and diameters. Examples of expandable element  18  constructed in accordance with the principles of the present invention are described in greater detail below.  
     [0046]FIG. 2 is a top view of the expandable element  18 . As shown in FIGS. 1 and 2, the expandable element  18  is in a deployed state. Further, FIG. 2 shows the expandable element having a substantially circular planar view, however, it will be readily understood that other shapes may be provided as well, for example, an oval shape, an amorphous shape, a spiral shape or a spider-like shape as discussed below.  
     [0047] The expandable element  18  has a wall  26  which defines an interior volume  28 , shown in FIG. 2 in phantom cut-away. The wall  26  is constructed of a resilient material that provides the ability to “deflate” or bundle the expandable element  18  into a bundled state, as shown in FIG. 3. Exemplary resilient materials include rubber, silicon, flexible and thermoplastic polymers.  
     [0048] Turning back to FIG. 2, the expandable element has a proximal side  30  which is opposite the tissue contact surface area  22  (not shown here) which may contact the skull. Provided on the proximal side  30  is a port  32 . The port  32  has a longitudinal axis extending through a center of the port  32 . FIG. 2 shows the port  32  positioned substantially in the center of the expandable element  18  on the proximal side  30 . However, it will be readily understood by those skilled in the art that port  32  can be positioned in alternate locations, for example along the periphery of wall  26 .  
     [0049]FIG. 3 illustrates a side view of the expandable element  18  shown in FIG. 1 in a bundled state. FIG. 3 shows the expandable element  18  having a bundled diameter d b  which preferably ranges in size up to 14 mm.  
     [0050]FIG. 4 is a side view of the expandable element  18  shown in FIG. 1 shown in the deployed state. In FIG. 4, the port  32  is provided substantially in the center of expandable element  18 . However, it will be readily understood that port  32  can be provided at alternate locations on the expandable element  18 . The port  32  provides a fluid communication pathway between the expandable element  18  and the body  12  (not shown). The port  32  is also in fluid communication with the interior volume  28  (not shown). As such, when the body  12  (not shown) is in fluid communication with the port  32 , the body  12  is also in fluid communication with the interior volume  28 . Alternate configurations of a connection arrangement between the body  12 , the port  32  and the interior volume  28  are discussed in further detail below. Expandable element  18  has a deployed diameter “d d ” measured at the widest part along the wall and a height “h” measured from a top  34  of the expandable element  18  to a bottom  36  of the expandable element  18 . A circular expandable element  18  constructed in accordance with the principles of the present invention can have a deployed diameter “d d ” ranging in size from 5 to 200 mm. An exemplary embodiment has a deployed diameter “d d ” of 48 mm. Another exemplary embodiment has a deployed diameter “d d ” of 64 mm. Further, an exemplary embodiment can have a height h ranging in size from 1 to 10 mm. In one exemplary embodiment the height h is approximately 5 mm.  
     [0051]FIG. 5 shows a perspective view of an alternate embodiment of the expandable element  18 , shown as a shaped expandable element  38 . The shaped expandable element  38  has at least one expandable element arm  40  which has a distal end  42  and a proximal end  44  opposite the distal end  42 , in which each expandable element arm  40  is joined at the proximal end  44  to a port  46  to create a “spider-like” expandable element arrangement. Each expandable element arm  40  has a height “g” measured from a top  48  of the expandable element arm  40  to a bottom  49  of the expandable element arm  40 . Further, each expandable element arm  40  has a width “w” measured from a first side  50  of the expandable element arm  40  to a second side  51  of the expandable element arm  40 . Further, each expandable element arm  40  preferable has approximately a 2 to 1 width w to height g ratio. The materials used to construct the shaped expandable element  38  include one or more of compliant, non-compliant, and partially compliant polymers.  
     [0052] In use, deployment of the shaped expandable element  38  occurs as with the above-described expandable element  18 . Alternately, deployment of a plurality of the expandable element arms  40  can occur individually. The ability to selectively deploy individual expandable element arms  40  is provided by an individual injection member for each expandable element arm  40  (injection members are more fully discussed below). In practice, an injection member that corresponds to an individual expandable element arm  40  is provided with a flow of thermal fluid, which thereby inflates or deploys the corresponding expandable element arm  40 . The above described shaped expandable element can be manufactured by standard polymer tube technology processes.  
     [0053]FIG. 6 is a sectional view of the body  12  taken along section  6 - 6  in FIG. 1. The body  12  has a body wall  52  which defines at least one lumen. An inlet conduit  56  provides a conduit for the infusion of a fluid into the expandable element  18 . Further, an outlet conduit  60  provides a conduit for removal of a fluid from the expandable element  18 . However, it is contemplated that the functions of the inlet conduit  56  and the outlet conduit  60  can be reversed.  
     [0054] When the body  12  is connected to the expandable element  18 , the inlet conduit  56  and the outlet conduit  60  are in fluid communication with the interior volume  28 . As such, fluids can be introduced and evacuated from the interior volume  28  by way of the inlet conduit  56  and the outlet conduit  60  of the body  12 . Further, the body  12  can be a catheter which allows a user to position the expandable device  10  at a tissue treatment site.  
     [0055]FIG. 7 is an alternate sectional view of the body  12  taken along section  6 - 6  in FIG. 1. FIG. 7 shows the inlet conduit  56  provided substantially coaxial with the longitudinal axis of the body  12 . Further, the outlet conduit  60  is provided with a elongated shape along a partial portion of the outer circumference of the inlet conduit  56 . Additionally, a conduit  62  located along the outer circumference of the inlet conduit  56  and opposite the outlet conduit  60  is provided for carrying accessory components, such as temperature and/or pressure sensor lead lines (not shown). It will be readily understood by one skilled in the art that either the first or second lumen can interchangeably act as an inlet conduit or an outlet conduit.  
     [0056]FIG. 8 is another alternate sectional view of the body  12  taken along section  6 - 6  in FIG. 1. FIG. 8 shows the inlet conduit  56  centered within the body wall  52  of the body  12  and two outlet conduits  60  provided around a portion of the outer circumference of the inlet conduit  56  within the body  12 .  
     [0057]FIG. 9 is another alternate sectional view of the body  12  taken along section  6 - 6  in FIG. 1. FIG. 9 shows a plurality of outlet conduits  60  and a centrally located inlet conduit  56  provided around a portion of the outer circumference of the outlet conduit  60  within the body  12 . Optionally, a conduit  62  can be provided to carry accessory components as discussed herein.  
     [0058] From these examples, it will readily understood that many alternate arrangements can be made. For example, one or more accessory conduits can be provided in any of the above disclosed configurations, the first and second lumens can act as either inlet or outlet conduits and additional structures may be incorporated.  
     [0059]FIG. 10 shows a cut-away perspective view of the expandable portion of the device in a deployed state. Referring to FIG. 10, operation of this exemplary embodiment is discussed. In use, the thermally transmissive fluid is transferred into the interior volume  28  through the inlet conduit  56  and evacuated from the interior volume  28  through the outlet conduit  60 . Circulation of the thermally transmissive fluid within the interior volume  28  transmits or removes thermal energy to or from the expandable element wall  26  by convection, which characteristics are known to those skilled in the art. It is contemplated that a steady thermal state can be maintained between the treatment site and the expandable element  18  or that desirable thermal changes can be affected.  
     [0060] Additionally, the present invention distributes the thermally transmissive fluid in order to thermally control portions along the surface of the device  10 . It is contemplated that many different methods of distributing the fluid can be used. Several exemplary fluid distribution methods are described herein. One such method is provided by supplying a fluid distribution feature within the expandable element  18 , embodiments of which are discussed in more detail below.  
     [0061]FIG. 11 is a sectional planar view taken along section  11 - 11  in FIG. 1. FIG. 11 shows an interior surface  64  of the contact surface  22 , which is disposed within the interior volume  28  of the expandable element  18 . Affixed to the interior surface  64  is at least one vane  66 . It is contemplated that one or more vanes  66  can be used and that their shape can be varied to advantageously affect fluid distribution within the interior volume  28  or to affect structural shape of the bundled or deployed expandable element. For example, FIG. 11 shows four vanes  66  extending radially from a center longitudinal axis to an outside periphery of the expandable element  18 . The vanes  66  define flow pathways for the thermally-transmissive fluid. The vanes  66  can be small ridges of protruding material or other such raised structures. As such, the vanes provide for even distribution of the thermally transmissive fluid within the interior volume  28 , thereby reducing areas of uneven temperature. It will be readily understood by one of ordinary skill in the art that different configurations can be employed to efficiently distribute thermally-transmissive fluid within the interior volume  28  of the expandable element  18  or to selectively distribute the thermally-transmissive fluid to specific portions of the interior volume  28 .  
     [0062]FIG. 12 shows another embodiment of a fluid distribution element with a greater number of vanes  66 . FIG. 12 shows a plurality of “S”-shaped vanes  66  affixed to the interior surface  64  and extending radially outward from a center longitudinal axis. It is contemplated that the vanes  66  are affixed to other surfaces in communication with the interior volume  28 . Further, the vanes  66  can be free-floating within the interior volume  28 .  
     [0063]FIG. 13, shows a cut-away end view of an expandable device in a deployed state constructed in accordance with the principles of the present invention. FIG. 13 shows the interior volume  28  having at least one injection member  68  provided therein. FIG. 13 shows four such injection members  68 . However, it will be readily understood that various configurations may be provided.  
     [0064] Focusing on one injection member  68 , the injection member  68  has a proximal end  70  and a distal end  72 . The proximal end  70  is in fluid communication with the inlet conduit  56  of the body  12  (not shown and as described above). A junction  74  is provided to facilitate connection of the injection member  68  to the inlet conduit  56 , however, other arrangements without a junction  74  can also be employed, as discussed herein. Further, the distal end  72  defines an opening  76  for fluid output flow. Alternatively, an injection member  68  could have one or more openings  76  along a length of the injection member  68 , whether an opening at the distal end  72  is provided or not. Although all of the exemplary injection members  68  are shown in FIG. 13 as having equal lengths, it is contemplated that each individual injection member  68  can have the same or a length different from at least one other injection member  68 . Additionally, the injection member  68  can be extruded from a urethane/pellethane material having a relatively soft durometer or manufactured by other processes know in the art.  
     [0065] Referring to FIGS. 1 and 13 operation of the device is discussed, in use, thermally transmissive fluid is infused into the inlet conduit  56  at the proximal end  14  of the body  12 . The fluid then passes to the distal end  16  of the body  12  and through the injection member  68 , which directs the fluid to pre-specified locations within the interior volume  28 . In an exemplary embodiment the fluid is directed to a periphery  78  of the expandable element  18 . The thermally transmissive fluid thereby imparts or removes thermal energy from the tissue contact surface area  22 . The tissue contact surface area  22  can then affect a temperature of the tissue at a treatment site. The fluid is then evacuated from the interior volume  28  via the outlet conduit  60  and returned to the proximal end  14  of the body  12  for recovery or reuse. This process can be a continuous flow or can be regulated in cycles or steps.  
     [0066] As such, the thermally transmissive fluid is directed to a pre-selected area of the interior volume  28  to provide for a reduction in the occurrence of uneven temperature areas within the interior volume  28 . Further, it is contemplated that different lengths and different numbers of injection members  68  can be used to optimize a desired temperature distribution. Further still, different temperature zones at different locations over the tissue contact surface area  22  of the expandable element  18  can be provided as desired.  
     [0067]FIG. 14 is a sectional view of an exemplary interface region taken along section  14 - 14  in FIG. 1. For exemplary purposes only, FIG. 14 shows a body  12  configuration as shown in FIG. 6, however, it is contemplated that other body  12  configurations can be provided. A filler  80  forms a fluid tight seal between the inlet conduit  56  and the injection members  68 , thereby providing a path of fluid communication from the inlet conduit  56  to the openings  76  and in turn, to the interior volume  28  of the expandable element  18 . Further, the filler  80  is any suitable material having bonding properties, for example, silicone, rubber, flexible polymers, epoxies or other bonding components. FIG. 14 shows two injection members  68 , however, it is contemplated that any quantity of injection members  68  can be provided.  
     [0068]FIG. 15 is a perspective view of a junction  74  of a device constructed in accordance with the principles of the present invention. A junction  74  can be formed from the filler  80  described above, formed from a “plug” of material or other methods may be employed, for example, the junction  74  can be machined or injection molded.  
     [0069] A plurality of injection members  68  are attached and in fluid communication with the junction  74 . In turn, junction  74  is attached to and in fluid communication with the inlet conduit of the body  12 , as discussed below. FIG. 14 shows four injection members  68 , however, it is contemplated that any quantity of injection members  68  can be provided.  
     [0070]FIG. 16 is a sectional view of another exemplary interface region taken along section  14 - 14  in FIG. 1. Junction  74  is disposed at least partially within the inlet conduit  56  and is fixedly attached and in fluid communication therewith. The junction  74  is attached to the inlet conduit  56  by methods known in the art. Additionally, outlet conduit  60  is shown in partial sectional view. Both the injection members  68  and the outlet conduit  60  are in fluid communication with the interior volume  28  of the expandable element  18 . For exemplary purposes only, FIG. 16 depicts a body  12  configuration as shown in FIG. 7, however, it is anticipated that alternate configurations can be provided.  
     [0071]FIG. 17 is a cut-away, perspective view of an alternate body arrangement constructed in accordance with the principles of the present invention. FIG. 17 shows a plurality of injection members  68  disposed within outlet conduits  60  which are located inside a portion of the periphery of the body wall  52  (some shown in cut-away). Further the inlet conduit  56  is provided in the center of the body  12 .  
     [0072]FIG. 18 is a cut-away, perspective view of another alternate body arrangement constructed in accordance with the principles of the present invention. FIG. 18 shows a plurality of injection members  68  disposed within a plurality of inlet conduits  56 . A centrally located outlet conduit  60  is also provided.  
     [0073]FIG. 19 is a sectional view taken along section  19 - 19  in FIG. 5 constructed in accordance with the principles of the present invention. FIG. 19 shows a expandable element arm  38  having an arm wall which defines the interior volume  28 . Provided within the interior volume  28  is an injection member  68  having an opening  76  which is in fluid communication with the interior volume  28 . It is contemplated that all or some of the expandable element arms  40  shown in FIG. 5 can have an injection member  68  provided therein. The attendant advantages of such an arrangement are discussed with reference to other expandable element configurations herein. For example, temperature control along the expandable element arms  40  and selective deployment of individual arms can be provided.  
     [0074]FIG. 20 is a perspective view of an alternate embodiment of an injection member arrangement constructed in accordance with the principles of the present invention. FIG. 20 shows an alternate injection member arrangement having a unitary structure  84  which includes at least one injection tube arm  86 . Further, unitary structure  84  has an inlet port  88 . The injection tube arm  86  defines a tip opening  90 . The unitary structure  84  is configured so that inlet port  88  is fixedly attached to inlet conduit  56  at the distal end  16  of the body  12 . The entire unitary structure  84  is enveloped by the expandable element  18  (not shown). In practice, thermally conductive fluid is introduced into the unitary structure  84  and then flows into the expandable element  18  via tip opening  90 . As such, the expandable element  18  is “inflated” with thermally conductive fluid, which thereby affects the temperature of the expandable element.  
     [0075]FIGS. 21, 22 and  23  are side, overhead and bottom views respectively, each showing the unitary structure  84 . While four injection tube arms  86  are shown, it is understood that other arrangements having fewer or greater quantities of injection tube arms  86  can be provided. The unitary structure  84  can be constructed from flexible material by casting, extruding or other suitable means. For example, injection molding can be used.  
     [0076]FIG. 24 is a perspective view of an exemplary system constructed in accordance with the principles of the present invention. An expandable element  18  is in a bundled state attached to the distal end  16  of the body  12 . FIG. 24 shows inlet conduit  56  and outlet conduit  60  in phantom lines. Inlet conduit  56  is in fluid communication with a thermally-conductive fluid source  94  via body  12 . Further, inlet conduit  56  is in fluid communication with the interior volume  28  (not shown) of the expandable element  18 . Further still, the outlet conduit  60  is in fluid communication with the interior volume  28  (not shown) of the expandable element  18 . The outlet conduit is in fluid communication with the thermally-conductive fluid source  94  via body  12 . Inlet conduit  56  and outlet conduit  60  are in fluid communication with the interior volume  28  of the expandable element  18  and define a fluid circulation circuit.  
     [0077] In practice, the expandable element  18  is inserted in its bundled state  92  into the body of a subject to be treated. When the expandable element  18  is positioned at a desired treatment region, fluid is introduced into the expandable element  18  via the thermally-conductive fluid source  94 —body  12  circuit, thereby “deploying” the expandable element. When the expandable element is in its deployed state, the fluid continues to flow through the circuit and thereby thermally affects the expandable element  18 , which thereby thermally affects the tissue treatment site.  
     [0078]FIG. 25 is a perspective view of the exemplary system of FIG. 24 showing the expandable element  18  in a deployed state  98 . For the sake of simplicity, those elements described with respect to FIG. 24 are not again described.  
     [0079] In practice, once the expandable element  18  is deployed, the thermally-transmissive fluid enters the interior volume  28  of the expandable element  18  through inlet conduit  56  thereby thermally affecting the wall  26  of the expandable element  18  by convection. At or about the same time, outlet conduit  60  excavates the thermal-transmissive fluid from the interior volume  28  of the expandable element  18 . In this manner, the thermally-transmissive fluid affects a specific, controlled temperature to the wall  26  of the expandable element  18 . Additionally, the wall  26  of the expandable element  18  can be fully or partially perfusive of fluid, to thereby allow fluid to directly contact tissue for treatment purposes. In addition, a medicament or other treatment fluid can be administered in this manner.  
     [0080] It is contemplated that the expandable element  18  can be deployed by various methods, for example, by inflation with the thermally-transmissive fluid, by mechanical supports, by employing a built-in biased shape of the expandable element  18 , or other methods known in the art.  
     [0081] Specific construction of exemplary embodiments is now discussed in more detail. Expandable element and shaft materials are varied to accommodate specific applications. When used in an exemplary application, such as epidurally in the skull, to control temperature locally in the brain, the materials are preferably soft and pliable, for example composed of silicone polymer, soft pellethane (such as pellethane 80AE) or Pebax 42. Other applications may require the expandable element to have separate characteristics such as more durability or different compliant/non-compliant requirements. The thermally-transmissive fluid can be saline or a refrigerant which is cooled by a thermoelectric cooler or a refrigerant fluid. It is noted that cooled fluid can be used to chill cerebrospinal fluid.  
     [0082] Exemplary uses of the devices of the invention are now discussed in more detail. The above-described devices advantageously provide a physician with a way to control the temperature of a localized region of brain tissue by infusing a chilled or heated thermally-transmissive fluid, such as saline, into the expandable element and allowing convection to complete the thermal transfer between the localized brain tissue and the expandable element. This is preferably accomplished through a burr hole in the skull. The exemplary application advantageously provides a chilled fluid in order to lower the localized brain temperature as a neuroprotective means in a cerebral ischemia condition. Also it is contemplated that the above-described device can additionally be used to cool localized regions of the brain in a brain trauma patient as a way to lower cerebral metabolic requirements and minimize brain edema. Furthermore, the device can also be used in any post-operative trauma situation when the possibility of cerebral edema exists and it is desired to be abated or minimized.  
     [0083] It is contemplated that the device described above can also be used in alternate procedures, for example, the device can be placed through the nose into the ethmoid sinus (neck skull bone) to cool carotid blood as it courses through the cavernous sinus up to the brain. Further, the device can be placed adjacent the hypothalamus and a warmed fluid circulated through the device to raise the temperature perceived by the hypothalamus, thereby triggering peripheral vasodilation and systemic cooling.  
     [0084] Further, the above described device can be used in other parts of the body in instances where local tissue temperature needs to be controlled or modulated. In such instances, thermal therapy may involve either chilled or heated fluid inside the expandable element to achieve the desired result. For example, the device could be applied to organs prior to or post transplant (e.g. kidney) to minimize ischemia and swelling. Further, the device could use be used to minimize uterine irritability in a female subject that is at risk for premature delivery.  
     [0085] In an alternative embodiment, as shown in FIG. 26, the expandable element  18  is coupled to an attachment device  100 . The attachment device has a housing  102  with a first end region  104 , for attachment of the expandable element  18 , and a second end region  106  having a thermally conductive fluid inlet  108  and outlet  110 , where the expandable element  18  is in fluid communication the thermally conductive fluid. Optionally, as shown in FIG. 27, radial threads  112  are provided about the exterior surface of the first end region  104  to facilitate attachment of the housing  102  to a boney structure such as a skull. However, it is contemplated that non-threaded arrangements can also be provided or coupled to or on the housing  102 , for example, flutes, barbs, ridges or other such elements.  
     [0086] The housing  102  can be constructed of any suitable material, for example metals, plastics or a combination thereof. It is contemplated that the housing  102  has a diameter “D”, measured at the widest portion of the device, from less than one centimeter to approximately ten centimeters. In exemplary embodiments, the diameter ranges from approximately one centimeter to approximately two centimeters.  
     [0087] In an exemplary embodiment, as shown in FIG. 27, the expandable element  18  has a substantially conical flask shape. The shape advantageously allows form fitting to the dura matter while providing a large tissue contacting surface area, that fits into the space between the dura and the skull. The expandable element  18  can be easily compressed to a size sufficiently small to fit through a burr hole in the skull, which when inflated the expandable element  18  expands to provides maximal thermal transfer. Additionally, the tissue contact surface area  22  can have a shape ranging from substantially flat to concave or being flexible enough to conform to natural contours on the tissue surface. Alternatively, the expandable element  18  can have a substantially cylindrical or bell or shape.  
     [0088] In an exemplary method of use, as shown in FIG. 28, the attachment device  100  is threaded into a burr hole  114  in a skull  116 , such that the expandable element  18  is positioned within a space between the dura tissue  118  and the skull  120 . The expandable element  18  is configured such that when in a deployed state the expandable element  18  fits within the space between the dura tissue  18  and the skull  116 , with the tissue contacting surface  22  substantially conforming to the dura matter  18 . The thickness of the skull is exaggerated for illustrative purposes, and is not intended to be accurate a representation of skull thickness.  
     [0089] In an exemplary embodiment, the expandable element  18  is infused with a low-pressure thermally conductive fluid to expand its shape to a deployed state, the expansion causing contact with the tissue to be treated. The fluid can thereby impart a thermal change to the expandable element which in turn imparts a thermal change to the contacted tissue. For example, the expandable element can be deployed with a thermally conductive fluid having a pressure of between about 0 psi and 5 psi.  
     [0090] It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.