Abstract:
A tool that has an introducer having a space therein and a distal aperture at the distal end thereof, and a spike movable within the introducer, may be used in a surgical method for treating a vessel wall. A tissue plug may be removed from the vessel wall with the spike, whereby an opening remains in the vessel wall. The spike then may be moved within the space in the introducer in a direction away from the longitudinal centerline of the distal aperture. An object then may be delivered through the introducer and out of the distal aperture to the opening in the vessel wall.

Description:
[0001]     This application is a continuation of U.S. patent application Ser. No. 10/698,569, filed on Oct. 31, 2003; which in turn is a divisional of U.S. patent application Ser. No. 09/542,976, filed on Apr. 4, 2000; all of which are hereby incorporated by reference in their entirety. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The invention relates to a surgical method for treating a vessel wall.  
         [0004]     2. Brief Description of the Related Art  
         [0005]     Vascular anastomosis is a procedure by which two blood vessels within a patient are surgically joined together. Vascular anastomosis is performed during treatment of a variety of conditions including coronary artery disease, diseases of the great and peripheral vessels, organ transplantation, and trauma. In coronary artery disease (CAD) an occlusion or stenosis in a coronary artery interferes with blood flow to the heart muscle. Treatment of CAD involves the grafting of a vessel in the form of a prosthesis or harvested artery or vein to reroute blood flow around the occlusion and restore adequate blood flow to the heart muscle. This treatment is known as coronary artery bypass grafting (CABG).  
         [0006]     In the conventional CABG, a large incision is made in the chest and the sternum is sawed in half to allow access to the heart. In addition, a heart lung machine is used to circulate the patients blood so that the heart can be stopped and the anastomosis can be performed. During this procedure, the aorta is clamped which can lead to trauma of the aortic tissue and/or dislodge plaque emboli, both of which increase the likelihood of neurological complications. In order to minimize the trauma to the patient induced by conventional CABG, less invasive techniques have been developed in which the surgery is performed through small incisions in the patients chest with the aid of visualizing scopes. Less invasive CABG can be performed on a beating or stopped heart and thus may avoid the need for cardiopulmonary bypass.  
         [0007]     In both conventional and less invasive CABG procedures, the surgeon has to suture one end of the graft vessel to the coronary artery and the other end of the graft vessel to a blood supplying vein or artery. The suturing process is a time consuming and difficult procedure requiring a high level of surgical skill. In order to perform the suturing of the graft to the coronary artery and the blood supplying artery the surgeon must have relatively unobstructed access to the anastomosis site within the patient. In the less invasive surgical approaches, some of the major coronary arteries including the ascending aorta cannot be easily reached by the surgeon because of their location. This makes suturing either difficult or impossible for some coronary artery sites. In addition, some target vessels, such as heavily calcified coronary vessels, vessels having very small diameter, and previously bypassed vessels may make the suturing process difficult or impossible.  
         [0008]     Accordingly, it would be desirable to provide a sutureless vascular anastomosis device which easily connects a graft vessel to a target vessel and can be deployed in limited space.  
         [0009]     Deployment of a sutureless anastomosis device, such as those described in U.S. patent application Ser. No. 09/314,278, involves forming an opening in the target vessel and inserting the anastomosis device with a graft vessel attached into the opening. Accordingly, it would be desirable to provide a one piece tool which can perform both tissue punching and anastomosis device deployment. In order to provide a one piece device it would be desirable to provide a tissue punch which is advanced through a trocar and then is moved out of the trocar to allow deployment of the anastomosis device through the same trocar.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention relates to a tissue punch for forming an opening in a target blood vessel for deploying an anastomosis device to connect a graft vessel to the target vessel.  
         [0011]     In accordance with one aspect of the present invention, an apparatus for piercing a vessel, punching a hole in the vessel, removing punched tissue from the vessel, and introducing an object into the vessel through the punched hole is described. The apparatus includes a punch with a pointed piercing end for piercing a vessel to allow introduction of the punch into the vessel, a tubular element arranged coaxially with the punch through which the punch retracts to remove vessel tissue, and an introducer located coaxially around the tubular element. The introducer includes an area into which the punch and tubular element can be moved to allow introduction of an object into the punched hole in the vessel through the introducer.  
         [0012]     In accordance with another aspect of the present invention, a tissue punch includes a piercing element, a cutting edge, and a trocar receiving the piercing element. The piercing element has a pointed distal end, a tissue receiving space, and an anvil adjacent the tissue receiving space. The cutting edge is arranged to contact the anvil to cut a piece of tissue. The trocar has a side opening for removing the piercing element from the trocar after punching tissue.  
         [0013]     In accordance with an additional aspect of the present invention, a method of punching a plug of tissue from the wall of a blood vessel includes the steps of penetrating the wall of the blood vessel with a piercing element to form an opening in the blood vessel, punching a plug of tissue around the opening in the blood vessel, and inserting a trocar into the punched hole in the blood vessel.  
         [0014]     In accordance with a further aspect of the invention, a double tissue punch includes a piercing element having a pointed distal end and a first anvil surface; a first cutting element movable with respect to the piercing element, the first cutting element having a cutting edge-arranged to contact the first anvil surface; and the first cutting element having a second anvil surface, a second cutting element movable with respect to the piercing element and the first cutting element, the second cutting element having a cutting edge arranged to contact the second anvil surface.  
         [0015]     The present invention provides advantages of a tissue punch which is deployed through a trocar and is removed through a side wall of the trocar so that the trocar can subsequently be used for deployment of a medical device. The invention also provides the advantage of trapping a tissue plug which is cut by the tissue punch. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     The invention will now be described in greater detail with reference to the preferred embodiments illustrated in the accompanying drawings, in which like elements bear like reference numerals, and wherein:  
         [0017]      FIG. 1  is a perspective view of a tissue punch according to the present invention in a tissue penetrating position;  
         [0018]      FIG. 2  is a perspective view of the tissue punch of  FIG. 1  with the piercing element withdrawn inside the trocar;  
         [0019]      FIG. 3  is a perspective view of the tissue punch of  FIG. 1  as the piercing element is pivoted out of the trocar;  
         [0020]      FIG. 4  is a perspective view of the tissue punch of  FIG. 1  with the piercing element pivoted further;  
         [0021]      FIG. 5  is a perspective view of the tissue punch of  FIG. 1  with the piercing element completely removed from the trocar;  
         [0022]      FIG. 6  is an exploded perspective view of a tissue punch having a cam release system;  
         [0023]      FIG. 7  is a perspective view of the tissue punch of  FIG. 6  in an assembled, tissue penetrating position;  
         [0024]      FIG. 8  is a partially cut away perspective view of the tissue punch of  FIG. 6  in a tissue cutting position;  
         [0025]      FIG. 9  is a perspective view of the tissue punch of  FIG. 6  after tissue punching is completed;  
         [0026]      FIG. 10  is a partially cut away view of  FIG. 9 ;  
         [0027]      FIG. 11  is a perspective view of the tissue punch of  FIG. 6  with the piercing element and tissue trap partially removed from the trocar;  
         [0028]      FIG. 12  is a perspective view of the tissue punch of  FIG. 6  with the piercing element and tissue trap completely removed from the trocar;  
         [0029]      FIG. 13  is an exploded perspective view of a tissue punch having a bendable tab release system;  
         [0030]      FIG. 14  is a perspective view of the tissue punch of  FIG. 13  in an assembled tissue penetrating position;  
         [0031]      FIG. 15  is a partially cut away view of  FIG. 14 ;  
         [0032]      FIG. 16  is a partially cut away perspective view of the tissue punch of  FIG. 13  after tissue cutting is completed;  
         [0033]      FIG. 17  is a partially cut away perspective view of the tissue punch of  FIG. 13  with the piercing element and tissue trap partially removed from the trocar;  
         [0034]      FIG. 18  is a partially cut away perspective view of the tissue punch of  FIG. 13  with the piercing element and tissue trap completely removed from the trocar;  
         [0035]      FIG. 19  is an exploded perspective view of a tissue punch having a snap release system;  
         [0036]      FIG. 20  is a perspective view of the tissue punch of  FIG. 19  in an assembled tissue penetrating position;  
         [0037]      FIG. 21  is a partially cut away view of  FIG. 20 ;  
         [0038]      FIG. 21A  is an isolated perspective view of the piercing element and tissue trap of  FIG. 21 ;  
         [0039]      FIG. 22  is a partially cut away perspective view of the tissue punch of  FIG. 19  after tissue punching is completed;  
         [0040]      FIG. 23  is a partially cut away perspective view of the tissue punch of  FIG. 19  with the piercing element and tissue trap partially removed from the trocar;  
         [0041]      FIG. 23A  is an isolated perspective view of the piercing element and tissue trap of  FIG. 23 ;  
         [0042]      FIG. 24  is a perspective view of the tissue punch of  FIG. 19  with the piercing element and tissue trap completely removed from the trocar; and  
         [0043]      FIGS. 25-30  are schematic side views of a double tissue punch showing a series of steps in a punching sequence with the double tissue punch. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0044]     The tissue punch according to the present invention is used to create a hole in a wall of a target blood vessel for receiving an anastomosis device to connect a graft vessel to the target vessel. The tissue punch includes a piercing element for penetrating the target vessel wall, a cutter for cutting a plug of tissue, and a trocar which is inserted in the opening in the wall after punching has been completed. After punching is complete, the piercing element is removed from the trocar and the anastomosis device is then deployed through the open lumen of the trocar.  
         [0045]     The tissue punch according to the present invention is particularly useful for use in coronary artery bypass grafting (CABG) in which a graft vessel is connected at opposite ends to the aorta and to a coronary artery. However, the target vessel which is punched with the tissue punch can be any vessel including but not limited to the aorta, coronary artery, and arteries leading to the arms or head. The graft vessel for connection to the target vessel can be an arterial graft, a venous graft, or a synthetic prosthesis, as required. The anastomosis procedure is preferably performed with minimally invasive procedures, without the stoppage of blood flow in the target vessel, and without the use of cardiopulmonary bypass. However, the anastomosis procedure may also be performed as a stopped heart and/or open chest procedure.  
         [0046]     Preferably, the tissue punches-according to the present invention are incorporated in a one piece tool which performs tissue punching and deployment of the anastomosis device. This one piece tool may be operated manually, such as by cams, or automatically, such as pneumatically.  
         [0047]      FIG. 1  is a perspective view of a tissue punch  10  according to the invention which includes a one-piece piercing element  14  positioned within an introducer sheath or trocar  16 . The piercing element  14  can be advanced and retracted in the trocar  16  by an elongated member  18  such as a spring steel strap or cable which extends through an opening  20  in a side of the trocar. The piercing element  14  includes a pointed distal tip  22  for penetrating the target vessel wall and a narrow shaft portion  28  around which the tissue of the target vessel wall contracts after piercing. The distal tip  12  may be formed, for example, as a conical surface or by a plurality of ground surfaces extending to a point at the distal tip. An anvil surface  24  is located on the piercing element  14  between the distal tip  22  and the shaft  28 . The anvil surface  24  acts with a cutting edge  26  of the trocar  16  to cut an annular plug of tissue.  
         [0048]     In operation, the piercing element  14  is forcibly advanced to puncture the target vessel wall. After piercing, the tissue of the target vessel wall rests around the shaft portion  28  of the piercing element  14 . The piercing element  14  is then pulled back inside the trocar  16  by the elongated member  18  to cut an annular plug of tissue by compressing the tissue between the anvil surface  24  of the piercing element and the cutting edge  26  of the trocar  16 . The cut plug of tissue can be trapped in an annular space surrounding the shaft  28  and removed from the surgical site on the piercing element  14 .  
         [0049]     By using the tissue punch  10  to cut a plug of the target vessel wall tissue in this manner, there is less tendency for tearing. In particular, the punched opening in the vessel wall is less apt to tear than an incision or puncture. A puncture opening is particularly apt to tear when an anastomosis device is inserted into the opening or when the opening is expanded by expansion of the anastomosis device.  
         [0050]      FIGS. 1-5  illustrate the steps of punching and then removing the piercing element  14  from the side opening of the trocar  16  to allow the anastomosis device to be deployed through the lumen of the trocar. In  FIG. 1 , the piercing element  14  is in an extended piercing position. In this position, the tissue punch is advanced into the target vessel wall. The tissue punch  10  is preferably advanced by spring actuated motion provided by a tool on which the tissue punch is mounted. Alternatively, the tissue punch may be advance manually.  
         [0051]     As shown in  FIG. 2 , the piercing element  14  is withdrawn into the trocar  16  by pulling on the elongated member  18  (shown in  FIG. 1 ). Once the distal tip  22  of the piercing element  14  clears the distal end of the opening  20 , the piercing element is pivoted as it is retracted out of the opening  20  in the side of the trocar  16  as shown in  FIGS. 3-5 .  
         [0052]     As shown in  FIG. 1 , the piercing element  14  includes two side pins  30  connected to the elongated member  18 . The piercing element  14  is retracted by pulling on the elongated member  18  or other arrangement to accomplish punching of the tissue in the manner described above. During such retraction, a pin  34 —on the underside of the piercing element  14  travels in a slot  36  in the trocar  16  until it reaches a stop  38  at the proximal end of the slot. When the pin  34  hits the stop  38 , the piercing element  14  is caused to pivot about the stop as shown in  FIG. 3 .  
         [0053]     Further retraction of the piercing element  14 , as shown in  FIG. 4 , causes an inclined proximal surface  40  of the piercing element to contact an edge  42  of the trocar opening  20  such that the piercing element rotates out of the opening  20 . As shown in  FIG. 5 , the piercing element continues to rotate to a storage position outside the trocar  16 . When the piercing element is in the storage position, the inside of the trocar  16  can be used to maintain the opening in the blood vessel and for delivery of an anastomosis device to the incision in the target vessel.  
         [0054]      FIGS. 6-24  illustrate alternative embodiments of tissue punches including tissue traps for trapping and retaining the plug of tissue which is cut by the tissue punch. The trapping of tissue plug prevents possible complications which could occur if the plug of tissue is released in the surgical site.  
         [0055]      FIG. 6  illustrates a tissue punch  50  which includes a piercing element  54 , a trocar  56 , a tissue trap  58 , and a collar  60 . The tissue punch  50  is assembled as illustrated in  FIG. 7  with the piercing element  54  positioned within the tubular tissue trap  58  with a pin  62  of the piercing element extending out through a slot  64  of the tissue trap. The tissue trap  58  includes two side pins  66  which extend through corresponding openings  68  in the collar  60 . The side pins  66  also extend into cam slots  72  in the trocar  56 . The piercing element  14  also includes a slot  74  at a proximal end which receives an elongated member  76  shown in  FIG. 7 . The elongated member  76  is preferably a spring steel strap which is used as a pull wire to pull the piercing element  54  into the tissue trap  58  and as a spring to move the piercing element and tissue trap out of the opening  78  in the side wall of the trocar  56 .  
         [0056]     The punching procedure using the tissue punch  50  of  FIGS. 6-12  will be described with respect to the sequence of steps shown in  FIGS. 7-12 . In the assembled position illustrated in  FIG. 7 , the piercing element  54  pierces the tissue of the blood vessel wall by automatic or manual advancement of the tissue punch. As shown in  FIG. 8 , after piercing the piercing element  54  is withdrawn inside the tissue trap  58  by pulling on the elongated member  76  to cut a plug of tissue with a cutting edge  70  of the tissue trap  58 .  
         [0057]     As shown in  FIGS. 9 and 10 , as the piercing element  54  is withdrawn, the pin  62  slides along the slot  64 . When the pin  62  contacts the curved proximal end of the slot  64  the piercing element is prevented from rotating by the spring strap element  76  and the tissue trap is caused to rotate. When the tissue trap  58  rotates the side pins  66  rotate in the cam slot  72  unlocking the tissue trap and piercing element  54  from the trocar  56 . As the tissue trap  56  is further withdrawn, as shown in  FIG. 11 , the tissue trap slides back into the opening  78  in the trocar  56 . Finally, as shown in  FIG. 12 , the spring bias of the elongated spring member  76  causes the tissue trap  58  and piercing element  54  to be moved out of the trocar  56  to allow the lumen of the trocar to be used for deployment of a medical device, such as an anastomosis device.  
         [0058]     The collar  60  of the tissue punch  50  is used as a spacer to hold the tissue trap  56  at a center of the trocar lumen. It should be understood that the collar  60  may be formed as a part of the tissue trap  58  or as a separate element.  
         [0059]      FIGS. 13-18  illustrate an alternative embodiment of a tissue punch  80  having a bendable tab release system. As shown in the exploded view of  FIG. 13 , the tissue punch  80  includes a piercing element  84 , a trocar  86 , and a tissue trap  88 . As in the embodiment of  FIGS. 6-12 , the piercing element  84  includes a proximal slot  90  for receiving an elongated member  94  which acts as a pull wire and spring. The tissue trap  88  includes a plurality of tabs  94  which are cut and folded out from the tube of the tissue trap. The trocar  86  includes a plurality of openings  96  for receiving the plurality of tabs  94 . The plurality of openings  96  are also provided with slots  102  which extend to a distal end of the trocar  56 .  
         [0060]     As shown in  FIG. 14 , the tissue punch  80 , in an assembled configuration prior to punching, axially has the tabs  94  positioned within the openings  96  to lock the tissue trap  88  in position axially with respect to the trocar  86 . The tissue trap  88  is locked in place to allow cutting of the tissue with the cutting edge  98  of the tissue trap.  
         [0061]     The steps of operating the tissue punch  80  according to  FIGS. 13-18  are illustrated in the sequence of steps shown in  FIGS. 14-18 . In  FIGS. 14 and 15  the tissue punch is shown assembled for punching. The tissue punch is advanced into the tissue of a target vessel wall automatically or manually. Once the target vessel wall has been penetrated, the piercing element  84  is withdrawn by pulling on the elongated member  92  to cut a plug of tissue with the cutting edge  98 .  FIG. 16  illustrates the position of the piercing element  84  after punching is complete.  
         [0062]     As shown in  FIG. 17 , the piercing element  84  continues to be withdrawn until it abuts a stop member  100  inside the tissue trap  88 . Continued withdrawal of the piercing element  84  pulls both the piercing element and the tissue trap  88  proximally and causes the tabs  94  to fold over allowing the tissue trap to be released from the trocar  86 . As shown in  FIG. 18 , when the tissue trap  88  is released from the trocar  86 , the spring force of the elongated member  92  moves the tissue trap and piercing element  84  out of the trocar.  
         [0063]      FIGS. 19-24  illustrate a further embodiment of a tissue punch  110  having a snap release system. The tissue punch  110  includes a piercing element  114 , a trocar  116 , a tissue trap  118 , and a collar  120 . The collar  120  includes two legs  122  having tabs  124  at the ends. The collar  120  is fixed to the tissue trap  118 . The tissue trap  118  has a cutting edge  126  and two slots  128  for accommodating the legs  122  and tabs  124  of the collar  120 . The piercing element  114  has a tapered distal tip  130 , a narrow shaft portion  132 , and a larger shaft portion  134 . In the assembled-tissue penetrating position shown in  FIGS. 20, 21 , and  21 A the tabs  124  are positioned adjacent the larger portion  134  of the shaft. The tabs  124  extend outward through openings  136  in the trocar  116  and lock the collar  120  and tissue trap  18  in position with respect to the trocar  166 .  
         [0064]     After punching, the piercing element  114 , tissue trap  118 , and collar  120  are removed as follows. As the piercing element  114  is withdrawn by the elongated member  138  as shown in  22 ,  23 , and  23 A, the tabs  124  of the collar  120  are positioned adjacent the narrow portion of the shaft  132 . This allows the tabs  124  to flex inward releasing the tabs from the openings  136  in the trocar  116 . Once the collar  120  is released from the trocar  116 , the piercing element  114 , the tissue trap  118  and the collar  120  move out of the trocar  116  by the spring action of the elongated member  138  and allow the trocar to be used for insertion of a medical device.  
         [0065]      FIGS. 25-30  illustrate a sequence of tissue punching with a double punch system for forming an opening in the wall of a blood vessel. The double punch system  150  is used to make openings larger than those made by a single punch embodiment. For openings larger than about 3 mm a double punch is preferred since a piercing element with a largest diameter of greater than about 3 mm tends to cause excessive trauma to the tissue.  
         [0066]     As shown in  FIG. 25 , the double punch system  150  includes a piercing element  154  having a first anvil  156 , a spreading element  158  having a second anvil  160  and a first cutter  162 , and a sleeve  164  having a second cutter  166 . As shown in the sequence of  FIGS. 26-30 , the piercing element  154  is first inserted through the tissue  170  of a blood vessel wall until the tissue rests around a shaft  172  of the piercing element. The spreading element  158  is then moved downwards as shown in  FIG. 27  to cut a first plug of tissue  174  with the first cutter  162 . The first plug  174  is contained within an interior of the spreading element  158  which forms a tissue trap.  
         [0067]     As shown in  FIG. 28  the spreading element  158  is then advanced through the tissue  170  until the tissue rests around a shaft  178  of the spreading element. The sleeve  164  is then advanced, as shown in  FIG. 29 , to cut a second plug of tissue  180  with the second cutter  166 . The second plug of tissue  180  is contained within the sleeve  164  which forms a tissue trap.  
         [0068]      FIG. 30  illustrates the withdrawal of the double punch system  150  containing the two annular plugs  174 ,  180  of tissue and leaving a tissue opening  184 .  
         [0069]     It should be understood that the double punch system is illustrated as a system for forming holes which are larger than an approximately 3 mm hole which can be easily formed with a single punch system. The double punch system can form holes of up to about 8 mm in diameter without causing tissue trauma. In order to make holes of larger diameters additional spreading elements and cutting elements can be used to form a triple punch system or other multiple punch system.  
         [0070]     While the invention has been described in detail with reference to the preferred embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made and equivalents employed, without departing from the present invention.