Abstract:
A device for occluding a blood vessel, comprises a blunt dissection needle and a first occlusion clip releasably mounted to a distal end of the blunt dissection needle, the first occlusion clip being biased to assume a clamped configuration in combination with a retaining element which, in a first configuration, retains the first occlusion clip in an insertion position against an outer surface of the blunt dissection needle and, in a second configuration, releases the first occlusion clip to assume the clamped configuration.

Description:
BACKGROUND 
       [0001]    Conventional treatments to alleviate the symptoms of uterine fibroids include drug therapies which are generally effective only in less advanced cases, myomectomies to remove individual larger fibroids and, for more advanced cases, hysterectomies. Less invasive alternative procedures are often preferable as they typically reduce side effects and involve fewer side effects and shorter hospital stays. 
         [0002]    These less invasive procedures include the shrinkage of fibroids using probes that delivery electrical energy, heat or cryogenic cooling to the tissue and procedures involving occlusion of the blood supply to the fibroids. Some of these vascular occlusion procedures including, for example, embolization and mechanical constriction of blood vessels, are complex and may require multiple incisions to reach the target tissue and/or to place devices accurately in desired positions relative to target anatomical structures. 
       SUMMARY OF THE INVENTION 
       [0003]    In one aspect, the present invention is directed to a device for occluding a blood vessel, comprises a blunt dissection needle and a first occlusion clip releasably mounted to a distal end of the blunt dissection needle, the first occlusion clip being biased to assume a clamped configuration in combination with a retaining element which, in a first configuration, retains the first occlusion clip in an insertion position against an outer surface of the blunt dissection needle and, in a second configuration, releases the first occlusion clip to assume the clamped configuration. 
         [0004]    The present invention is also directed to a method of treating uterine fibroids, comprising forming an incision in a side of a vaginal fornix proximate to a uterine artery and advancing a distal end of a blunt dissection needle through the incision to a position adjacent to the uterine artery in combination with deploying an occlusion clip from the blunt dissection needle to clamp the uterine artery, the occlusion clip being biased toward a clamping configuration and withdrawing the blunt dissection needle leaving the occlusion clip on the uterine artery. The uterine artery may then be released after a predetermined time has elapsed to restore blood flow therethrough. 
     
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0005]      FIG. 1  is a side elevation view showing a blunt needle device to occlude a blood vessel according to an embodiment of the invention; 
           [0006]      FIG. 2  is a side view of the distal end of the blunt needle device of  FIG. 1 ; and 
           [0007]      FIG. 3  is a side elevation view showing a second embodiment of a blunt needle device according to the invention, with a suturing mechanism. 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    The present invention may be further understood with reference to the following description and to the appended drawings, wherein like elements are referred to with the same reference numerals. The present invention relates to methods and devices for reducing or stopping the flow of blood to fibroids or other target tissue within an organ (i.e. the uterus). In particular, the present invention relates to minimally invasive methods and devices for occluding blood flow through the uterine arteries. 
         [0009]    Embodiments of the present invention provide a system and method for occlusion of selected blood vessels reducing the need for specialized equipment such as, for example, radiological equipment as well as for the services of a specialist such as a radiologist. Procedures according to the present invention for treating tissue masses such as uterine fibroids take advantage of the location of the blood vessels supplying the tissue mass(es) to facilitate access thereto. For example, the uterine arteries which provide blood to the uterus and to any fibroids contained therein are located approximately 1 cm from the vaginal fornix. It is therefore possible to access the uterine arteries via the vaginal fornix using, for example, blunt dissection tools, as will be described in greater detail below. 
         [0010]      FIGS. 1 and 2  show an exemplary embodiment of a device for use in a procedure to locate and occlude vessels supplying blood to a target tissue mass such as a fibroid. In this example, the target tissue mass is a uterine fibroid and the blood vessels are the two uterine arteries. This procedure is minimally invasive, since the uterine arteries are reached through the vaginal fornix, without the need for incisions through the abdomen. According to the invention, a small incision is made in the vaginal fornix at the 3 o&#39;clock position (with reference to the longitudinal axis of the vagina, 12 o&#39;clock being at the top facing the cervix) to access the left uterine artery. The exemplary blunt dissection tool is, in this embodiment, a needle  100  including a distal end  104  formed as would be understood by those skilled in the art to be suitable for penetrating the flesh of the vaginal fornix and passing therethrough until the distal end  104  is adjacent to a first one of the uterine arteries. 
         [0011]    The needle  100  includes an occlusion clip  102  including a first jaw member  102 ′ extending along a distal portion of the needle  100  toward the distal end  104  and a second jaw member  102 ′ extending along the distal portion of the needle  100  on a side opposite the first occlusion clip  102 . Each of the first and second jaw members  102 ′ is coupled to the needle  100  and to one another via a spring mechanism  105  which biases the clip  102  toward a clipping configuration in which the first and second jaw members  102 ′ project substantially perpendicular to the needle  100  in contact with one another. Although the clip  102  is biased by the spring mechanism  105  toward the clipping configuration, it is held in place thereagainst by a retainer element which, in this embodiment, is formed as an outer tube  110  which is slidable relative to the needle  100  in the directions shown by arrow A in  FIG. 1 . When in an insertion configuration, a distal portion of the outer tube  110  covers at least a portion of each of the first and second jaw members  102 ′, preventing them from moving radially outward due to the bias of the spring mechanism  105 . Once the needle  100  has reached a desired position with the first and second jaw members  102 ′ adjacent to a target uterine artery, the outer tube  110  is moved proximally to expose the clip  102 , releasing the clip  102  to move outward to the clipping configuration gripping the target uterine artery and occluding blood flow therethrough. The clip  102  is coupled to the needle by a connecting wire  109 . 
         [0012]    After the occlusion clip  102  has clamped onto the target uterine artery, it is released from the needle  100  so that the needle  100  may be removed from the body through the incision. For example, once the clips  102  have moved to the clipping configuration gripping the target artery, a cutter  107  may be advanced through the needle  100  to shear the connective wire  109 , releasing the clip  102  from the needle  100 . The occlusion clip  102  is preferably formed of a biocompatible elastic or resilient material, for example, a metal, a plastic and may be a shape memory alloy or polymer. Those skilled in the art will understand that, where the clip  102  includes a shape memory material, the clip  102  may be formed so that, when released from the constraint of the outer tube  110 , the clip  102  automatically moves to the clipping configuration (i.e., reverts to a memorized shape adapted to clamp the target artery). This shape memory reversion to the clipping configuration may be employed in addition to or as an alternative to the spring mechanism  105 . 
         [0013]    The occlusion clip  102  may be deployed utilizing other methods in addition to the exemplary translating outer tube  110 . For example, an optional actuating wire  112  may extend through the dissection needle  100  to connect to the occlusion clip  102  so that, pulling a proximal end of the actuating wire  112  proximally ejects the occlusion clip  102  from the needle  100  onto a blood vessel or other structure positioned adjacent to the distal end  104  of the needle  100 . As would be understood by those skilled in the art, other conventional mechanisms may be used to release the occlusion clip  102  or a similar mechanical clamping device from the blunt dissection needle  100 , after the distal end  104  has been placed in a desired location adjacent to a blood vessel to be occluded. 
         [0014]    After the clip  102  has been deployed, the needle  100  is withdrawn from the first incision and a second needle  100  with another clip  102  thereon is inserted into a second incision proximate to the second (i.e., left) uterine artery (e.g., at the 9 o&#39;clock position of the vaginal fornix). The second needle  100  is advanced into the second incision until the distal end  104  is in a desired position adjacent to the second uterine artery and the second clip  102  is deployed to clamp the second uterine artery in the same manner as the first clip  102  was deployed. Alternatively, a needle  100  may include 2 clips  102  formed on radially opposite sides of the needle  100  so that this single needle  100  may be used to clip both uterine arteries. After the artery or arteries have been successfully occluded, the needle  100  is removed from the body via the vaginal opening. Those skilled in the art will understand the clips may be made of a bioresorbable material designed to maintain the occlusive force on the arteries only for a time during which it is desired to occlude blood flow through the arteries (e.g., a time sufficient to necrose the fibroids but insufficient to permanently damage non-targeted tissue of the uterus). As would be understood by those skilled in the art, this time may be approximately 6 hours or more. Alternatively, the clips may be left in place to permanently occlude flow through the arteries. 
         [0015]    As shown in  FIG. 2 , a blunt dissection tool  200  according to a second embodiment of the present invention includes a suturing mechanism for occluding a blood vessel by tying a suture therearound. The blunt dissection tool  200  comprises a large gauge blunt dissection needle  202  having a distal end  204 . The suturing mechanism comprises a needle carrier  206  having a predefined memorized shape. That is, the needle carrier  206  is preferably restrained to remain in a first shape (e.g., straight) while received within the blunt dissection tool  200  and then, when extended therefrom, the needle carrier  206  assumes the desired ‘memorized’ shape. Those skilled in the art will understand that this may be achieved by simply straightening the needle carrier  206  by inserting it into a confining space within the needle carrier  206  after imparting to it a natural bias toward the desired ‘memorized’ shape to which it will return as soon as the constraint of the confining space is removed. Alternatively, the needle carrier  206  may be formed of a shape memory material (e.g., Nitinol or any known shape memory polymer) so that, under predetermined conditions (e.g., when mechanically released) the carrier  206  will revert to the ‘memorized’ shape. As shown in  FIG. 2 , the needle carrier  206  is shaped to load and drive a needle and suture combination  214  away from the blunt dissection tool  200  and then back toward a needle catch  208 . 
         [0016]    In one exemplary embodiment, the needle carrier  206  of the suturing mechanism  212  is packaged and stored in the deployed state shown in  FIG. 2 , to maintain the proper geometry for guiding the needle and suture  214  during the procedure. After removal from the package, the needle with suture  214  is loaded in the needle carrier  206 . The carrier  206  is then pushed back to retract into the blunt dissection needle  202  in an insertion state. For example, the insertion configuration may be flush along the dissection needle  202 , or elongated within a cavity of said dissection needle  202 . The distal tip  204  of the dissection needle  202  is inserted into the incision, and using blunt dissection techniques is advanced to a depth corresponding to the location of one of the two uterine arteries. 
         [0017]    The desired location of the distal tip  204  relative to the blood vessels may be determined in different ways. For example, an ultrasound crystal  210  may be disposed near the distal tip  204 , to determine the nearest position relative to the uterine artery. The ultrasound crystal may emit acoustic energy that is reflected by the blood vessel, and is received and interpreted to determine the position of the blunt dissection needle  202  relative to the blood vessel. Alternatively, other sensing means to locate the target artery may be used. For example, a microphone may be used in place of the crystal  210 , to listen to the sound of flowing blood and to determine based on that sound when the distal tip  204  is in a sufficiently close position to the artery. 
         [0018]    Once the blunt dissection needle  202  has been placed in a desired position adjacent to a target uterine artery, the needle carrier  206  is advanced by, for example, moving a plunger  216  distally. The plunger  216  may comprise an actuation device at the proximal handle of the dissection tool  200 , where it is accessible to a user of the needle  202 . Advancement of the needle carrier  206  directs the needle and suture  214  around the target uterine artery along a predetermined path, until the needle and suture  214  are captured by the needle catch  208 . In this mode, the needle carrier  206  acts as a guide for the needle  214 , causing it to loop around the artery, with the suture attached thereto. 
         [0019]    The needle carrier  206  is returned to the retracted position after guiding the needle and suture  214 , for example by withdrawing the plunger  216  proximally and the entire blunt dissection needle  202  is removed through the incision, leaving the loop of suture behind around the uterine artery with ends of the suture loop extending out of the blunt dissection tool  200  so that they are accessible to the user. A knot is then tied with the ends of the suture loop and pushed therealong to ligate the blood vessel. Multiple knots may be made and pushed to the blood vessel, to ensure that the blood vessel remains occluded. This procedure is then repeated to treat the second one of the two uterine arteries to complete the treatment of the uterine fibroids. As with the clips  102  described above, the suture may be formed of bioabsorbable material so that the ligating force applied thereby will relax after the desired time (e.g., the time required to necrose the target tissue while leaving non-targeted tissues unharmed). Alternatively, the suture may be left in place to permanently occlude blood flow. 
         [0020]    The present invention has been described with reference to specific exemplary embodiments. Those skilled in the art will understand that changes may be made in details, particularly in matters of shape, size, material and arrangement of parts. Accordingly, various modifications and changes may be made to the embodiments of the invention. The specifications and drawings are, therefore, to be regarded in an illustrative rather than a restrictive sense.