Abstract:
A system for delivering an implantable medical device is provided including the medical device, a delivery wire that is rotationally coupled to the medical device, and a catheter. The delivery wire includes a spiraling marking extending around the delivery wire to provide visual confirmation that the wire is rotating. The medical device is delivered to a target site within a patient&#39;s body, and the delivery wire is rotated to release the medical device from the wire. Observation of the rotating spiral markings helps ensure that the medical device is being released from the wire. The rotational coupling between the delivery wire and the medical device limits the medical device from becoming unintentionally released, and allows for repositioning of the device within the body even after the device has been exposed from the catheter.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/783,235, filed Mar. 14, 2013, which is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    A standard procedure used in the treatment of endovascular diseases is the placement of medical devices, such as embolic coils, stents, and dilation balloons, among others, at a desired or targeted site (e.g., aneurysm, etc.) within a patient. The delivery of such a medical device has typically been accomplished by a variety of means, including the use of a catheter along with a pushing wire or a means of injection, as well as a system to which the device is attached during delivery and detached once the device has reached the intended site. These medical devices usually have a contracted shape that allows them to pass through the lumen of the body vessel and an expanded shape that occurs after being deployed at the targeted site. 
         [0003]    One specific example, of such a medical device is an embolic or occlusive device that is placed within a body vessel or vasculature of the human body to filter the flow of blood through a vessel in the vasculature or to block the flow of blood within a defect in the vessel, such as an aneurysm. One example among many widely accepted types of occlusive devices is a detachable helical wire coil whose coil windings are sized to engage the wall of the vessel. Detachable coils are usually selected when the anatomy is especially distal and tortuous, a risk of coil displacement exists, or a very precise placement of the coil is required. 
       SUMMARY 
       [0004]    A system for delivering a medical device to patient&#39;s body is provided, the system comprising: an elongate delivery wire having proximal and distal ends; an implantable medical device having proximal and distal ends, the proximal end of the medical device releasably attached to the distal end of the delivery wire; a rotatable connection releasably coupling the proximal end of the medical device to the distal end of the delivery wire, the rotatable connection being disengaged via rotation of the delivery wire relative to the medical device; and a spiraling marking disposed along at least a portion of the delivery wire for indicating rotation of the wire. 
         [0005]    In another form, a method for delivering an implantable medical device into a patient&#39;s body is provided, the method comprising: inserting a catheter into a patient&#39;s body and advancing the catheter toward a target site within the body; inserting a delivery wire and an implantable medical device through the catheter toward the target site, wherein the medical device is releasably attached to the delivery wire via a rotatable connection and the delivery wire includes a spiraling marking disposed thereon; rotating the delivery wire relative to the medical device; visually observing the spiraling marking rotate along with the delivery wire; and in response to rotating the delivery wire, releasing the medical device from its attachment to the delivery wire. 
         [0006]    Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. One skilled-in-the-art will understand that a helical coil is used in the Figures as an example of a medical device and that other medical devices may be utilized without exceeding the scope of the disclosure. 
           [0008]      FIG. 1  is a schematic view of a medical device delivery system having a delivery wire and an implantable medical device; 
           [0009]      FIG. 2  is a schematic view of one embodiment of a rotatable connection between the delivery wire and the implantable medical device shown disconnected; 
           [0010]      FIG. 3  is a schematic view of another embodiment of a rotatable connection between the delivery wire and the implantable medical device shown connected; 
           [0011]      FIG. 4  is a side view of the delivery wire illustrating a spiraling pattern thereon; 
           [0012]      FIG. 5  is a side view of the delivery wire illustrating another spiraling pattern; 
           [0013]      FIG. 6  is a side view of the delivery wire illustrating another spiraling pattern; 
           [0014]      FIG. 7  is a side view of the delivery wire illustrating another spiraling pattern; 
           [0015]      FIG. 8  is a side view of the delivery wire illustrating another spiraling pattern; 
           [0016]      FIG. 9  is a side view of the delivery wire illustrating another spiraling pattern; 
           [0017]      FIG. 10  is a side view of the delivery wire illustrating a sleeve with a spiraling pattern thereon; 
           [0018]      FIG. 11  is a schematic view of a guidewire and a catheter inserted into a patient&#39;s body; and 
           [0019]      FIG. 12  is a schematic view of the delivery wire and implantable medical device inserted through the catheter toward a target site within the patient&#39;s body. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The following description is merely exemplary in nature and is in no way intended to limit the present disclosure or its application or uses. It should be understood that throughout the description and drawings, corresponding reference numerals indicate like or corresponding parts and features. 
         [0021]    Referring to  FIGS. 1-12 , a medical device delivery system  10  includes a delivery wire  12 , a detachable medical device or embolization coil  14  attached to the delivery wire  12 , a catheter  16 , and a guidewire  18 . The delivery wire  12  and coil  14  combine to form a medical device assembly  19  that can be inserted through the catheter  14  for delivery at a target site within a patient&#39;s body. Once delivered to the target site, the coil  14  can be detached from the delivery wire  12  for implantation in the desired portion of the patient&#39;s body. 
         [0022]    With reference now to  FIG. 1 , the delivery wire  12  can include a proximal portion  20  and a distal portion  22 . The proximal portion  20  is intended for manipulation by the user to push the delivery wire  12  and coil  14  through the catheter  16  toward the target site. The distal portion  22  is releasably attached to the coil  14 . 
         [0023]    The wire  12  can be a solid core wire made from Nitinol or stainless steel. The wire  12  can have a diameter in the range of 0.010 to 0.035 in one form; however, other diameters of the wire  12  could also be used to suit the needs of the user. The length of the wire  12  depends on the location of the target site within the body and the distance that the wire  12  must travel through a tortuous body lumen to reach the target site. It will be appreciated that the length of the wire  12  can be selected from any length known in the art that would be suitable for such a delivery. The wire  12  is capable of being pushed through the catheter  16  to deliver the attached coil  14 , as well as having torqueability to enable the wire to be twisted, as further described below. In addition to the solid core construction, the wire  12  could also be in the form of a coiled wire, a braided wire, or some other composite wire that has sufficient pushability and torqueability, as known in the art. 
         [0024]    The medical device or embolization coil  14  has a proximal portion  24  and a distal portion  26 . The proximal portion  24  is releasably attached to the distal portion  22  of the delivery wire  12 . When the coil  14  has been delivered to the target site, the coil  14  can be released from the delivery wire  12  for implantation in the patient&#39;s body. 
         [0025]    The coil  14  can be any type of embolization coil suited for delivery through an elongate catheter. The coil  14  can be made from platinum, Nitinol, or other known embolization coil materials. The coil  14  can be formed as a solid core wire that is wrapped helically to create an elongate coiled form, and can be further formed or bent into a desired embolization coil shape known in the art. One type of embolization coil shape is a conical shape, while another type of coil  14  is in the form of a flexible coil that can fold over itself to fill the shape of the target site. Another type of coil  14  is in the form of a larger spiral coil. It will be appreciated that other known types of the embolization coil  14  could also be used. 
         [0026]    The medical device has been described as the embolization coil  14  above; however other types of implantable or otherwise deliverable medical devices could also be attached to the delivery wire  12  for releasable delivery to the target site. For example, occlusion devices, filter devices, or the like could be attached to the delivery wire  12  for delivery through the catheter  16  and released from the wire  12  after being delivered to the target site. However, for purposes of discussion, the medical device  14  will be referred to as the coil  14 . 
         [0027]    As described above, the coil  14  is releasably attached to the delivery wire  12 . More specifically, the proximal end  24  of the coil  14  is attached to the distal end  22  of the wire  12 . Even more specifically, the coil  14  is attached to the wire  12  via a rotatable connection  30 . The rotatable connection  30  includes a wire portion  32  and a coil portion  34 . The wire portion  32  is mounted to the distal end of the distal portion  22  of the wire  12 . The coil portion  34  is mounted to the proximal end  26  of the coil  14 . The wire portion  32  is rotatably attached to the coil portion  34 , so that rotation of the wire portion  32  will release the coil portion  34  and the coil  14  from the delivery wire  12 . 
         [0028]    In one form, as shown in  FIG. 2 , the rotatable connection  30  can be in the form of a screw-type connection  31 , where the wire portion  32  can be in the form of a threaded portion  40  at the distal end of the wire  12 . The threaded portion  40  can include external spiraling threads  42  to create the screw-type connection  31 . The coil portion  34  in this form can be in the form of a collar portion  44  having internal threads  46  that correspond to the threads  42  of the wire portion  32 . The wire portion  32  can be screwed into the coil  34  so that the threads  42  engage the threads  46  to create the rotatable connection  30 . To release the coil  14  from the wire  12 , the threaded portion  40  can be rotated relative to the collar portion  44  in the direction opposite the rotational direction used to connect the two portions. To achieve this relative rotation, the wire  12  can be rotated while the coil  14  remains fixed, or the coil  14  can be rotated while the wire  12  remains fixed. Alternatively, both the wire  12  and the coil  14  can be rotated in opposite directions. However, given the delivery of the coil  14  into the patient&#39;s body to the target site and the implantable nature of the coil  14 , the coil  14  will generally engage the body vessel and be limiting from rotating, so that in practice the wire  12  will likely be rotated while the coil  14  remains relatively rotationally stationary. The portions  32  and  34  can be integrally formed with the wire  12  and coil  14 , respectively, or be separate components attached or mounted thereto. 
         [0029]    The rotatable connection  30  can help ensure that the coil  14  remains connected prior to reaching the desired delivery location. It also helps ensure that that the coil  14  can be adjusted once it has been delivered but prior to being released from the wire  12 . For example, if the coil  14  is placed too far down the body vessel, the coil  14  can be pulled back. If the coil  14  is not far enough, it can be further pushed. In other systems, a coil can be delivered by being pushed through a catheter by a pusher wire, but without control over the coil once it has been pushed out of the catheter. Moreover, if the size of the coil was incorrect for the body vessel, such as being too small, the user may lose control of the coil and it could migrate down the body vessel to another area within the body, which is undesirable. Solutions for such a problem included the use of another tube or sleeve that housed the coil, but this added undesirable complexity and thickness to the design, while still limiting the ability to reposition the coil after being exposed from the tube in the body vessel. 
         [0030]    In another form, as shown in  FIG. 3 , the rotatable connection  30  can be in the form of an interlocking spiral connection  50 . The spiral connection  50  includes a wire portion  52  and a coil portion  54 . The wire portion  52  is mounted or attached to the distal end  22  of the wire  12 . The coil portion  54  is mounted or attached to the proximal end  24  of the coil  14 . The wire portion  52  and coil portion  54  each have corresponding spiraling shapes, so that they can be twisted together to create the spiral connection  50 . To release the coil  14  from the wire  12 , the coil  14  and wire  12  can be rotated relative to each other such that the wire portion  52  and coil portion  54  rotate relative to each other in a spiraling manner. Rotation in a first direction will increase the connection  50 , while rotating in the opposite direction will decrease the connection and ultimately release the coil portion  54  and the coil  14  from the wire  12 . The wire portion  52  and coil portion  54  are shown in  FIG. 3  as having space between their coils, but the space between the coils could be reduced such that it is a tighter fit. 
         [0031]    Of course, in addition to the screw-type connection  31  and the spiral connection  50 , other rotatable connections  30  could also be used that utilize relative rotation between components to release them from each other, while preserving the connection absent sufficient rotation. 
         [0032]    In practice, the wire  12  is the primary rotated component to create the relative rotation between the wire  12  and the coil  14  to release the coil  14  from the wire  12 . As mentioned above, when the coil  14  is delivered from the catheter  16 , the coil  14  can contact the body vessel and become anchored, as intended. Thus, the coil  14  is generally fixed rotationally, so the wire  12  can be rotated to release the coil  14  from the wire  12 . Additionally, given the placement of the coil  14  within the body, rotating the coil  14  while keeping the wire  12  relatively fixed rotationally can be difficult without the use of additional tools inserted into the body. Thus, the wire  12  is preferably rotated to release the coil  14  therefrom. 
         [0033]    With the coil  14  within the body, visualizing the rotatable connection  30  between the wire  12  and coil  14  can be limited relative to direct visualization. It is desirable to ensure that the coil  14  has been released from the wire  12  in response to the rotation of the wire  12 , but because the coil  14  is generally not available for direct visualization, it is desirable to observe the rotation of the wire  12 . However, determining whether the wire  12  is rotating can be difficult due to low light conditions that can exist in operating rooms or the need to monitor other portions of the procedure, such as the placement of the coil  14 . Furthermore, the users of the system  10  are often wearing gloves that can affect the tactile response of the wire  12 . Additionally, with the coil  14  generally fixed within the body vessel and the rotatable connection  30  keeping the coil  14  coupled to the wire  12 , attempted rotation of the wire  12  could be limited by the rotatable connection  30  being slightly stuck, or tension created in the connection  30  to prevent undesired release could act against initial attempts to rotate the wire  12 . Attempts to rotate the wire  12  could also result in the wire  12  slipping within the hands or fingers or the user that is attempting to rotate the wire  12 , so what may feel like rotating may not be. 
         [0034]    With reference to FIGS.  1  and  4 - 10 , to assist in confirming that the wire  12  is rotating, the wire  12  can include spiraling or helical markings  60  disposed on the wire  12 . The markings  60  can be in the form of a first line  62 , shown in  FIG. 4 , spiraling around the wire  12  at a constant rate. Rotation of the wire  12  will create a visual effect of the first line  62  moving along the length of the wire  12 , thereby indicating that the wire  12  is being rotated, and indicating that the rotatable connection  30  is being disengaged to release the coil  14 . 
         [0035]    In another form, shown in  FIG. 5 , the helical marking pattern  60  can include a second line  64  that spirals alongside the first line  62 . The second line  64  can be made of the same color as the first line, or it can be made from a different color to increase contrast and provide additional visualization. In  FIG. 5 , the second line  64  is shown having a different hatching pattern than the first line  62  to illustrate the different color or appearance, but this hatching is merely illustrative and not necessarily indicative of the appearance of the lines  62  and  64 . 
         [0036]    The first line  62  can have a first thickness that can be selected from a wide range of line thicknesses to provide the desired visualization effect. The second line  64  can be of the same thickness as the first line  62  ( FIG. 5 ), or the second line  64  can have a thickness that is greater, as shown in  FIG. 6 , or smaller than the first line  62  to provide another type of contrast of thick and thin lines moving together. 
         [0037]    The wire  12  can also include a non-marked portion  66 , shown in  FIGS. 4-9 , that provides contrast to the first line  62  and/or second line  64 . The shape of the non-marked portion  66  depends on the size and shape of the first line  62  and/or second line  64 . In one form, the first line  62  can spiral around the wire  12  such that distance between adjacent spirals of the line  62  is approximately the same as the thickness of the line  62 , to create the appearance of two directly adjacent lines spiraling together, as shown in  FIG. 7 . Of course, the distance between adjacent spirals of the line  62  can be larger or smaller to change the relative thickness of the non-marked portion  66 , as shown in  FIGS. 4-6 . 
         [0038]    The above description of the distance between adjacent spirals of the line  62  can apply to the distance between the first line  62  and the second line  64 . In another form, the first line  62  and second line  64  can be arranged so that they spiral together as a pair being a first distance apart, but the spiraling shape is such that the distance between adjacent spirals of the pair is greater than the distance between the lines  62  and  64  that define the pair, as shown in  FIG. 8 . 
         [0039]    In another form, as shown in  FIG. 9 , the first line  62  can have a spiraling pattern where the distance between adjacent spirals changes as the line  62  spirals about the wire  12 . For example, the spacing between adjacent spirals can decrease as the line  62  spirals in the proximal direction. Conversely, the spacing between adjacent spirals can increase as the line spirals in the proximal direction. In another form, the spacing between adjacent spirals of the line  62  can increase and then decrease as the line  62  spirals in the proximal direction. It will be appreciated that other varying distance configurations at different longitudinal points along the length of the wire  12  can also be used. 
         [0040]    While the above description has referred to the first line  62  and/or the second line, it will be appreciated that above variations of the line size, shape, color, etc. can apply to both the first line  62  and second line  64 . Moreover, it will be appreciated that more than two lines can be used to suit the needs of the user. 
         [0041]    The markings  60  can be applied to the wire  12  either directly or indirectly. In one form, the markings  60  can be in the form of Teflon coating that is extruded or painted directly onto the wire  12 . In another form, the markings  60  can be applied to a polymer jacket  70  through which the wire  12  is inserted, with the jacket  70  being attached directly to the wire  12 , as shown in  FIG. 10 . It will be appreciated that other manners of applying the spiraling marking  60  can also be used. 
         [0042]    In another form, in the case of a coiled or braided type of wire, the markings  60  can be in the form of individual strands or wires that define the overall wire  12 . A portion of the strands that form the braided wire  12  can be one color while the other portions are other colors. Adjacent coils that form the coiled wire  12  could be different colors. 
         [0043]    The above described markings  60  can be applied to the full length of the wire  12 , or the markings can be applied to proximal portion  20  while the distal portion  22  remains free from the markings  60 , as shown in  FIG. 1 . Because the markings  60  are used to determine whether the wire  12  is rotating, the distal portion  22 , which is generally disposed inside the body when the wire  12  is rotated, can be free from the markings  60 . 
         [0044]    The system  10  can further include a torque device  80  ( FIG. 1 ) that can be attached to the proximal portion of the wire  12  to assist the user in rotating the wire  12 . The torque device  80  can be clamped to the proximal portion of the wire  12  to provide the user with a more robust portion to grip and rotate the wire  12 . However, the wire  12  can still be rotated without the torque device  80 . 
         [0045]    The wire  12  and coil  14  can each include radiopaque markers  85  ( FIG. 1 ) disposed therein to assist in determining the location of the wire  12  and coil  14  within the body via fluoroscopy. With a fluoroscopic agent introduced into the body lumen, the user can monitor the position of the wire  12  and coil  14  to determine whether the coil  14  has been delivered to the desired target site, and that the coil  14  remains in place after being disconnected from the wire  12 . These markers  85  can also help assist in determining that the wire  12  and coil  14  have been disengaged from each other by monitoring the relative position of the markers  85  for the wire  12  relative to the markers  85  for the coil  14 . The markers  85  can be disposed at different locations on the wire  12  and coil  14  to suit the needs of the user. In one form, the markers  85  can be attached to each portion of the rotatable connection  30  to help determine whether the connection  30  has been disengaged. The markers  85  can also be applied to the distal end of the coil  14  to determine the depth that the coil  14  has been inserted relative to the vasculature. The markers  85  can be applied to the guidewire  16  and catheter  18  to similarly help determine their location within the vasculature. 
         [0046]    Having described the structure of the system  10 , the use of the system will now be described. 
         [0047]    The system  10  can be inserted into the patient&#39;s body using known methods of insertion, such as a percutaneous method. A fluoroscopic agent can be introduced into the vasculature to aid fluoroscopic monitoring of the system  10  within the body. The guidewire  16  can be inserted into the patient&#39;s vasculature and advanced toward the target site where delivery of the coil  14  is desired. The position of the guidewire  16  can be monitored using the markers  85 . 
         [0048]    With reference to  FIG. 11 , the catheter  18  can be inserted into the body over the guidewire  16  and advanced along the guidewire  16  toward the target site. The catheter  18  positioning can be monitored via fluoroscopy and markers  85  attached to the catheter  18 . With the catheter  18  positioned at the target site, the guidewire  16  can be retracted out of the body. Additional contrasting agents can be delivered through the catheter  18  and toward the target site. 
         [0049]    With the catheter  18  delivered and the contrasting agent delivered to the target site, the user can determine the size of coil  14  that the user would like to deliver depending on the measured size of the target area. In one form, the wire  12  and coil  14  are in an assembled form, so the user can select the appropriate assembly of the wire  12  and coil  14  depending on the desired size. 
         [0050]    If the coil  12  and wire  14  are not pre-assembled, the coil  14  can be attached to the wire  12  via the rotatable connection  30  by rotating the components relative to each other in a first direction to engage the rotatable connection  30 . 
         [0051]    With reference to  FIG. 12 , the coil  12  and wire  14  can be inserted through the catheter  18  toward the target site. The position of the coil  14  relative to the target site can be monitored using fluoroscopy. The coil  14  can be advanced out of the catheter  18  by continued advancement, and the deployment of the coil  14  can be monitored. If the position of the coil  14  is undesirable, the user can retract the wire  12  to retract the coil  14 , even after the coil  14  has been exposed fully from the catheter  18 , because the rotatable connection  30  keeps the wire  12  and coil  14  attached to each other. The coil  14  can then be repositioned into the desired location. This can be repeated until the position of the coil  14  is in the preferred location. 
         [0052]    With the coil  14  in the desired location, the coil  14  can be detached from the wire  12 . As described above, the wire  12  can be rotated, which rotates the spiral markings  60  thereon. The user can observe the spiral markings  60  to confirm that the wire  12  is rotating. By confirming that the wire  12  is rotating, the user can ensure that the rotatable connection  30  is being disengaged. With rotation of the wire  12  confirmed by observing the rotating spiral markings  60 , the user can direct its attention to the coil  14  to watch the coil  14  detach under fluoroscopy. If the user attempts to rotate the wire  12  but the spiral markings  60  are not observed rotating, then the user can determine that the wire  12  has been limited or prevented from rotating, and the user can attempt to determine the cause of the limited rotational ability. 
         [0053]    With detachment of the coil  14  confirmed, the wire  12  can be retracted from the catheter  18 , and the catheter  18  can be refracted, and the percutaneous access site can be closed to complete the procedure. 
         [0054]    The foregoing description of various embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Numerous modifications or variations are possible in light of the above teachings. The embodiments discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled. 
         [0055]    As a person skilled in the art will readily appreciate, the above description is meant as an illustration of implementation of the principles this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation, and change, without departing from the spirit of this invention, as defined in the following claims.