Patent Abstract:
Methods and devices using magnetic force to form an anastomosis between hollow bodies. End-to-side, side-to-side and end-to-end anastomoses can be created without using suture or any other type of mechanical fasteners, although such attachment means may be used in practicing some aspects of the invention. Magnetic anastomotic components may be attached to the exterior of a vessel, e.g., by adhesive, without extending into the vessel lumen. Various magnetic component configurations are provided and may have different characteristics, for example, the ability to match the vessel curvature or to frictionally engage the vessel.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present application claims priority from the following copending patent applications: application Ser. No. 09/915,226, filed Jul. 23, 2001; application Ser. No. 09/638,805, filed Aug. 12, 2000; application Ser. No. 09/562,599, filed Apr. 29, 2000; provisional application Ser. No. 60/255,635, filed Dec. 13, 2000; application Ser. No. 09/851,400, filed May 7, 2001; provisional application Ser. No. 60/323,923, filed Sep. 15, 2001 and PCT application no. PCT/US01/25197 filed Aug. 10, 2001. The entire disclosure of each of the above-referenced patent applications is expressly incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The invention relates to forming anastomoses between two hollow bodies, and more specifically, using magnetic force to form such anastomoses.  
         [0004]     2. Description of Related Art  
         [0005]     Various non-suture based anastomotic systems have been proposed in the art, however, none has performed well enough to receive any significant level of acceptance in the field. Many of the proposed couplings fail to remain sufficiently patent, either acutely or chronically. Another technical challenge is to create an anastomosis that produces a fluid-tight seal between the hollow bodies. This is due in large part to the difficulty in securing an anastomotic component without overly traumatizing the tissue and without placing too much foreign material in the vessel lumen.  
       SUMMARY OF THE INVENTION  
       [0006]     One embodiment of the invention provides an anastomotic component that is coupled or attached to the wall of a vessel without protruding into the lumen of the vessel or penetrating the vessel wall. That is, substantially none of the anastomotic component or assembly is located within the vessel lumen (i.e., after the anastomosis has been formed). As a result, there is preferably no foreign structure or material disposed within the target vessel lumen after creating the anastomosis.  
         [0007]     The specific manner in which the anastomotic component is secured to the vessel may vary according to the invention. In one embodiment biocompatible adhesive is used to secure a component to the exterior of the target vessel wall without extending into the lumen. This component is coupled to a magnetic or ferromagnetic assembly carried on a graft vessel. Another embodiment uses adhesive to secure the anastomotic components to both vessels.  
         [0008]     According to further embodiments magnetic force is used in combination with an additional locking force, for example, a mechanical connection, to maintain the vessels in proper position and provide heightened resistance to pressure fluctuations that might occur post-formation of the anastomosis. Alternative constructions for the anastomotic components are disclosed, as are various delivery devices and methods for deploying the components. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0009]     Other features, benefits and advantages of the present invention will be apparent from the following detailed description of preferred embodiments thereof taken in conjunction with the accompanying drawing figures, wherein:  
         [0010]      FIGS. 1A and 1B  are, respectively, plan and elevation views of a magnetic anastomotic component constructed according to one embodiment of the invention;  
         [0011]      FIG. 1C  is an elevation view of a magnetic anastomotic component constructed according to an alternative embodiment of the invention;  
         [0012]      FIGS. 2A and 2B  are, respectively, perspective and elevation views of a magnetic anastomotic component constructed according to another embodiment of the invention;  
         [0013]      FIGS. 3A and 3B  are, respectively, perspective and elevation views of a magnetic anastomotic component constructed according to yet another embodiment of the invention;  
         [0014]      FIG. 4  is a perspective view showing the anastomotic component of  FIGS. 3A and 3B  attached to a vessel;  
         [0015]      FIGS. 5A and 5B  are perspective views showing an anastomotic component being secured to a vessel according to another embodiment of the invention;  
         [0016]      FIGS. 6A-6C  are elevation views showing anastomotic components constructed according to different embodiments of the invention being used to form an anastomosis between two vessels;  
         [0017]      FIGS. 7A-7C  are elevation views showing an anastomotic component being secured to a vessel according to another embodiment of the invention;  
         [0018]      FIG. 7D  is an elevation view showing the component of  FIGS. 7A-7C  being secured to an end of a vessel;  
         [0019]      FIGS. 8A and 8B  are perspective views of magnetic anastomotic components provided with tissue anchoring elements according to another embodiment of the invention;  
         [0020]      FIGS. 9A-9C  are elevation views, in section, showing magnetic anastomotic components provided with tissue traction-enhancing structure according to another embodiment of the invention;  
         [0021]      FIGS. 10A-10C  are, respectively, perspective views and a sectional view of one of the magnetic anastomotic components shown in  FIG. 9C ;  
         [0022]      FIGS. 11A and 11B  are, respectively, plan and sectional views of a magnetic anastomotic component provided with tissue gripping structure according to another embodiment of the invention;  
         [0023]      FIG. 11C  is a sectional view of an anastomotic component having an alternative tissue gripping structure;  
         [0024]      FIGS. 12A-12D  are, respectively, perspective, side elevation, end elevation and plan views of a magnetic anastomotic component constructed according to another embodiment of the invention;  
         [0025]      FIGS. 13A-13C  are, respectively, perspective, side elevation and end elevation views of an anastomosis formed by a pair of magnetic anastomotic components constructed according to another embodiment of the invention;  
         [0026]      FIGS. 14A-14D  are, respectively, plan, perspective, end elevation and side elevation views of a magnetic anastomotic component constructed according to another embodiment of the invention;  
         [0027]      FIGS. 15A-15D  are, respectively, plan, perspective, end elevation and side elevation views of a magnetic anastomotic component having a similar construction as the component shown in  FIGS. 14A-14D ;  
         [0028]      FIGS. 16A-16B  perspective views showing an anastomotic component being mounted to the exterior surface of a hollow body according to one embodiment of the invention;  
         [0029]      FIGS. 16C-16D  perspective views showing an anastomotic component being mounted to the exterior surface of a hollow body according to one embodiment of the invention;  
         [0030]      FIGS. 17A and 17B  are, respectively, perspective and end elevation views of an extravascular anastomosis created according to one embodiment of the invention;  
         [0031]      FIGS. 18A-18D  are perspective views showing an anastomotic component being mounted to the exterior surface of a hollow body according to another embodiment of the invention; and  
         [0032]      FIG. 19  is an end elevation view of a magnetic anastomotic component mounted to the exterior of a vessel according to one embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0033]      FIGS. 1A and 1B  show a first embodiment of a magnetic anastomotic component  10  having a ring-shaped body  12  and an opening  14 . As shown in  FIG. 1B  the component body  12  is generally flat. However, as shown in  FIG. 1C , the body  12  may be curved, for example, to match the curvature of a vessel to which it is secured.  
         [0034]      FIG. 2A  shows a magnetic anastomotic component  16  with an opening  18 . The body of the component  16  has an oval or elliptical shape with leading edges  20  for facilitating atraumatic introduction into a vessel. As shown in  FIG. 2B , the component  16  is flat. As in the above embodiment, however, the component  16  could be curved instead, for example, in a manner similar to the curvature of the anastomotic component  22  shown in  FIGS. 3A-3B . Also, the curvature may extend over all or a portion of the length (or width) of the component.  
         [0035]      FIG. 4  shows the anastomotic component  22  of  FIGS. 3A and 3B  mounted on the side wall of a vessel V. According to the preferred embodiments, the component is secured to the vessel without projecting into the vessel lumen, thereby avoiding potential problems associated with foreign material located in the vessel lumen. The component may be secured to the exterior of the vessel by suitable means, for example, adhesive, mechanical fasteners, or both.  
         [0036]      FIGS. 5A and 5B  show the anastomotic component  16  of  FIGS. 2A and 2B  mounted on a side wall of a vessel V.  FIG. 5B  shows mechanical fastening means, the illustrated means being in the form of sutures S, which are used to attach the component  16  to the vessel V. While sutures S are shown, it will be recognized that any suitable mechanical fastener may be used, e.g., clips, stents, barbs, hooks, wires, etc.  
         [0037]     In the embodiments of  FIG. 4  and  FIGS. 5A-5B , the anastomotic component is secured to the exterior of the vessel wall by suitable means.  FIGS. 6A and 6B  show anastomoses between two vessels V 1  and V 2 . In  FIG. 6A , the vessels have mounted thereto, respectively, magnetically attracted anastomotic components  24 ,  26 . (For clarity, the components are shown slightly separated.) The components  24 ,  26  are rectangular in cross-section. In  FIG. 6B  the vessels V 1 , V 2  have mounted thereto, respectively, components  28 ,  30 . The components  28 ,  30  are provided with a curved exterior surface that generally corresponds to the curvature of the walls of vessels V 1  and V 2 .  
         [0038]     The anastomoses shown in  FIGS. 6A and 6B  are created without placing any component portion in the vessel lumen.  FIG. 6C  shows an embodiment wherein a vessel V 1  has an anastomotic component  32  secured thereto, while a vessel V 2  has an anastomotic component comprising portions  34 A and  34 B secured thereto. Unlike the embodiments of  FIGS. 6A and 6B , thought, the portion  34 B of the one component is disposed within the lumen of vessel V 2 .  
         [0039]      FIG. 7A  shows a vessel V prior to forming an opening in the wall thereof.  FIG. 7B  shows the vessel V after an opening O has been formed therein.  FIG. 7C  shows an anastomotic component  36  positioned around the outside of the opening in the vessel V. An internal locking member  38 , which may be in the form of a snap ring, is positioned within the vessel lumen and cooperates with a groove in component  36  to secure the vessel and component together.  FIG. 7D  shows an anastomotic component  40  positioned around the end of a vessel V. The internal locking component  38  cooperates with a groove in the component  40  to secure the component to the end of the vessel (as opposed to the side wall of the vessel, as in the previous embodiments).  
         [0040]      FIG. 8A  shows a magnetic anastomotic component  42  having an opening  44  and a pair of attachment tabs  46  with openings  48 . The component  42  is mounted to the exterior of a vessel (not shown), for example, by passing a fastener (also not shown) through each opening  48  into engagement with the vessel tissue. Alternatively, the tabs  46  and openings  48  may be used as secondary securing means, for example, if the component  42  is secured to the vessel by other means, e.g., adhesive.  
         [0041]      FIG. 8B  shows a magnetic anastomotic component  50  having an opening  52  and attachment structure  54  to facilitate securing the component to a vessel (not shown). As above, the structure  54  may be used alone or in combination with other means for securing the component to the vessel. In the illustrated embodiment, the attachment structure  54  is affixed to the component  50  to define a plurality of openings  56  which may be use to receive sutures, clips, clamps, pins, barbs, or other securing or fastening means.  
         [0042]     One benefit of the embodiments of  FIGS. 8A-8B  and  9 A- 9 B is that the attachment structure is disposed away from (or below) the magnetic coupling surface of the component. That is, the exposed surface of the first component is free to mate with the exposed surface of the second component without interference from the attachment structure. As a result, one or both components can be firmly affixed to its vessel without adversely affecting the anastomosis.  
         [0043]      FIGS. 9A-9C  show three embodiments of magnetic anastomotic components that are provided with structure for increasing the traction or gripping force between the components and a vessel to which they are secured. In  FIG. 9A , anastomotic component portions  58 A,  58 B sandwich a vessel wall W and are preferably provided with a layer of material to enhance engagement with the tissue.  FIG. 9B  shows component portions  60 A and  60 B, each of which includes a projection  62  at the end thereof which grabs the tissue of the vessel wall W, thereby enhancing securement.  FIG. 9C  shows anastomotic component portions  64 A and  64 B, each of which is provided with a series of grooves or annulations  66  that grippingly engage the tissue of the vessel wall W.  
         [0044]      FIGS. 10A-10C  show an anastomotic component  68  with an opening  70  and a plurality of grooves or bumps  72 . The grooves or bumps  72 , which may also be in the forms of ridges, serrations, sharp or dull edges, etc., grab the tissue of the vessel to which the component is secured, which provides additional attachment force.  FIG. 10C  shows the ridges  72  having sharp points  74  to further enhance engagement with the tissue.  
         [0045]      FIGS. 11A-11C  show a magnetic anastomotic component  74  with an opening  76  and a peripheral edge  76  that defines a sharp point  78 . As shown in  FIG. 11B , a second anastomotic component  80  may be used with the component  74 , the component  80  having a complimentary-shaped edge  82  which cooperates with the edge  76  to sealingly and grippingly grab tissue of a vessel to which the components are secured.  FIG. 11C  shows a variation of the component  74  wherein a plurality of edges  74 ′ and  76 ′ are provided. A modified second component  80 ′ has a plurality of complimentary edges  82 ′ that mate with the edges  76 ′ of component  74 ′. In each of these embodiments the force-increasing structure is shown running along the entire length of the component. It will be appreciated that such structure may be extend along all or any portion of the component, and could extend across the width or longitudinal axis of the component, rather than along the axis, as in  FIGS. 10A-10C .  
         [0046]     The attachment force-increasing embodiments of  FIGS. 9A-9C ,  10 A- 10 C and  11 A- 11 C provide several benefits. In addition to enhancing attachment of the component to the vessel, the resulting anastomosis may have higher resistance to bursting under high pressures, e.g., acute pressure increases. For example, placing a rough or bumpy parylene coating on the surface of a magnetic component produces higher burst pressure resistance than using a smooth surface. It is desirable to increase pressure resistance, preferably without increasing the risk of occlusion.  
         [0047]     According to the invention, the components described above may be secured to the vessel by various means. For example, the component may be adhesively attached to the exertion of the vessel so that the lumen of the vessel is free of any component portion. In addition to the adhesive securement of the component, any of the above-described traction or tissue-gripping structure may be used as well. Additionally, the component may be provided with tabs or other attachment structure as described above.  
         [0048]      FIGS. 12A-12D  show a magnetic anastomotic component  84  having a rounded configuration designed to mate with the curvature of a vessel, and an opening  86  adapted to communicate with the vessel lumen. The thickness of the component  84  is tapered across its width ( FIG. 12C ) and may be tapered more or less from the specific configuration shown.  
         [0049]      FIGS. 13A-13C  show an anastomosis created according to another embodiment of the invention. A first vessel V 1  and a second vessel V 2  are provided with respective magnetically-attracted components  88 ,  90 . The component  88  has an intravascular portion  92  and an extravascular portion  94 , while the component  90  has an intravascular portion  96  and an extravascular portion  98  as shown best in  FIGS. 13A and 13C . The extravascular portions  94 ,  98  of the respective components are flat and provide a flat engagement to enhance the magnetic force holding the components together.  
         [0050]      FIGS. 14A-14D  show a magnetic anastomotic component  100  having a luminal opening  102  and a plurality of slots  104 . The slots  104  serve any of several purposes including allowing tissue ingrowth to promote attachment to the vessel, enhance traction between the component  100  and the vessel to which it is attached, etc.  
         [0051]      FIGS. 15A-15D  show a magnetic anastomotic component  106  with a luminal opening  108  and a plurality of apertures  110  disposed around its perimeter. The apertures  110  give the component  106  a frame-like structure and may serve any of the purposes described above with respect to the previous embodiment. It will be noted that the components  106  and  100 , while illustrated as being curved to match the curvature of a vessel or mating component (not shown), they may instead be flat or otherwise configured.  
         [0052]      FIGS. 16A and 16B  show a magnetic anastomotic component  112  being attached to a vessel V according to one embodiment of the inventions. An opening O is formed in an opening of a side wall of the vessel V and a magnetic anastomotic component  112  is moved into position such that the luminal  114  of the component is aligned with the opening O ( FIG. 16B ).  
         [0053]      FIGS. 16C and 16D  show a magnetic anastomotic component  116  being secured to a vessel V according to another embodiment of the invention. In this embodiment, the component  116  is lowered against and secured to the vessel wall as in the above embodiment. However, an opening is formed in the vessel after placing the component in this embodiment. As shown in  FIG. 17B , a suitable instrument is used to remove the tissue circumscribed by the opening  116  of the component  116 . The components  112  and  116  may be secured to the exterior of the wall of vessel V by any suitable means disclosed herein.  
         [0054]      FIG. 17A  shows an anastomosis between first and second vessels V 1  and V 2  which are provided, respectively, with magnetically attracted components  120 ,  122 . As shown in  FIG. 17B , of the components  120 ,  122  have mating surfaces which are positioned against each other and held by magnetism to create the anastomosis.  
         [0055]      FIGS. 18A-18D  show a magnetic anastomotic component being secured to the exterior of a vessel wall according to still another embodiment of the invention. Delivery device D includes an internal placement member  130  which is used to place a magnetic anastomotic component  132 . The placement member  130  is positioned within the lumen of the vessel through an incision in the wall, and the anastomotic component  132  is slid down against the exterior of the vessel. Magnetic attraction holds the component  132  in position around the incision.  
         [0056]     It should be noted that in positioning the placement member within the lumen of the vessel v, the delivery device is manipulated, typically by pulling up to tension the vessel wall, and the edges of the incision are positioned around a portion  134  of the delivery device D so as to make the incision the desired size. When the edges of the incision are so positioned, the anastomotic component  132  is slid down and the magnetic attraction captures the edges of the incision, thereby maintaining a suitable size opening.  
         [0057]     Next, the delivery device D is removed as shown in  FIG. 18C . Finally, as shown in  FIG. 18D , the internal placement member  130  is pushed distally and rotated and then removed (for example, by wires W) through the incision in the vessel V. The magnetic anastomotic component  132  is preferably provided with adhesive to secure the component to the vessel. Alternatively, adhesive may be applied around the incision on the vessel and the component  132  moved into contact therewith.  
         [0058]      FIG. 19  shows an embodiment of the invention where a magnetic anastomotic component  136  is secured to an intermediate member  138 , for example a dacron blanket, which itself is secured to the wall of a vessel V. These embodiments may be practiced by forming a blanket or surface of adhesive on the vessel exterior, and then forming the incision through the adhesive (which may be less difficult than incising the vessel wall directly).  
         [0059]     The invention may be practiced using any suitable biocompatible adhesives. In general, fibrin sealants and cyanoacrylate esters are the two types of adhesives widely used for biological bonding. Gelatin-resorcinol-formaldehyde glues have limited use as well. Other possible bioadhesives include gelatin-resorcinol-formaldehyde glue, bovine albumin, glutaraldehyde, marine organism (mussel) based, collagen and thrombin.  
         [0060]     Fibrin sealants are biodegradable, adhere well to connective tissue, promote wound healing, and generally have less bond strength than cyanoacrylate esters. A two-part system may be used to apply the sealant, or a one-part, ready-to-use formulation may be used instead. The adhesives used may have or not have antifibrinolytic agents (e.g., aprotinin, etc.)  
         [0061]     Those skilled in the art will recognize that many modifications, alterations and variations of the illustrated embodiments may be made without departing from the scope and spirit of the invention as defined by the appended claims. For example, while the embodiments are described in connection with magnetic anastomotic components, it will be appreciated that various features of the invention may be practiced in conjunction with non-magnetic anastomotic components. Further, it will be appreciated that, independent of the specific illustrated embodiments, the components disclosed herein may be used to create end-to-end, end-to-side or side-to-side anastomoses, between blood vessels or any hollow anatomical structures.

Technology Classification (CPC): 0