Abstract:
An instrument for everting an end of a vessel. The instrument has a frame and a mandrel having a distal end and a proximal end. The mandrel is mounted to the frame and axially movable. The distal end of the mandrel is insertable into the lumen of a vessel. A first wiping element and an opposed second wiping element are mounted to the frame with the mandrel positioned therebetween. The first and second wiping elements are laterally movable from a spaced-apart position to a closed position.

Description:
FIELD OF THE INVENTION 
     The field of art to which this invention relates is medical devices, more specifically, medical devices and surgical procedures for performing anastomosis of hollow organs such as blood vessels. 
     BACKGROUND OF THE INVENTION 
     Anastomotic surgical procedures are common in the field of cardiac surgery. These procedures are conventionally used for repairing a damaged or diseased blood vessel. In a typical anastomotic procedure, a surgeon joins a first blood vessel to a second blood vessel and creates a passageway between the two blood vessels to provide for the communication of blood flow. For this kind of anastomosis, the surgeon typically uses specialized grasping tools to manipulate a tiny, curved needle attached to an extremely fine surgical filament (e.g., under 0.001 inch diameter) to suture the vessels together. The vessels may be joined end-to-end, end-to-side, or side-to-side. To facilitate healing of the joined vessels, the prevailing standard of care requires that the surgeon suture the inside surfaces of the first and second vessels together, intima to intima. The surgeon must take great care not to damage the intima of each vessel so that endothelial cells may form over the anastomosis without the formation of thrombus or other complications, thus improving the likelihood of a long term patency of the vessels. For life-saving procedures such as coronary artery bypass graft surgery (CABG), this is especially important. When performing a distal anastomosis in a conventional CABG procedure, the surgeon typically sutures an end-to-side anastomosis of a distal end of a graft vessel (such as a segment of saphenous vein harvested from the patient) to a side of a target vessel (the stenosed coronary artery). For a proximal anastomosis in a conventional CABG procedure, the surgeon sutures a proximal end of the graft vessel to the side of the aorta. 
     As this field of art has progressed over the last several years, new anastomotic methods have been developed and introduced in attempts to replace the suturing technique briefly described above. Many of these methods incorporate novel fasteners and fastener appliers. The requirement, however, to maintain intima-to-intima contact of the joined vessels remains just as important with these approaches. In fact it is often necessary, prior to joining the vessels, for the surgeon to evert (i.e., turn inside out) the end of at least one of the vessels over the end of a member such as a tube, ferrule, or bushing, etc., which is a component of the fastener or fastener applier. This exposes the intima of that vessel for presentation to the intima of the other vessel prior to fastening the vessels. 
     Although it is possible to evert larger vessels (over 5 mm in diameter) using standard forceps and graspers available in the operating room, such methods are slow and may result in excessive damage to the vessel everted. And, often the surgeon requires assistance in performing the eversion procedure. Furthermore, vessels smaller than 5 mm are very difficult, if not impossible, to evert using such methods. 
     There are several requirements for an effective vessel eversion device. As noted earlier, for proper healing, it is important not to injure the intima of either vessel during the eversion procedure. The eversion device also must be easy for the surgeon to use without assistance and require only a few steps to operate. The eversion device must be useful for a wide range of blood vessel sizes, particularly small vessels, e.g., having a diameter of about 2-3 mm or less. In addition, it is desirable for the eversion device to be useful on one end of a vessel, when the opposite end is already attached to the patient (e.g., at the distal anastomosis of a patient undergoing a CABG procedure). The eversion device should also allow for the proper length of everted tissue, depending upon the requirements of the anastomosis device or method to be used. Finally, it is desirable that the eversion device be low cost and yet operate reliably. 
     Accordingly, there is a need in this art for novel devices and methods for engaging and everting the end of a blood vessel (or other tubular body organ), which can be used in a quick and effective manner without causing trauma to the vessel or the intima of the vessel (or tubular body organ). 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide novel eversion devices which are easy for the surgeon to use without assistance, and which efficiently and effectively engage blood vessels and evert the ends of blood vessels, including blood vessels having small or fine diameters. 
     A further object of the present invention is to provide novel eversion devices which engage blood vessels and evert the ends of blood vessels without causing trauma to the blood vessel or the intima of the blood vessels. 
     It is yet another object of the present invention to provide novel methods of engaging and everting blood vessels quickly and efficiently, while preventing or minimizing damage to the blood vessels and the intimas of the blood vessels. 
     It is still yet a further object of the present invention to provide a novel vessel eversion device and procedure for everting one end of a vessel having the other end already attached to another vessel. 
     Accordingly, an eversion instrument for everting an end of a vessel is disclosed. The instrument has a frame. There is a mandrel having a distal end and a proximal end. The mandrel is mounted to the frame and axially movable. The distal end of the mandrel being insertable into a lumen of a vessel. A first wiping element having a first wiping face and an opposed second wiping element having a second wiping face are mounted to the frame with the mandrel positioned therebetween. The first and second wiping elements are laterally movable from a spaced-apart position to a closed position. 
     Yet another aspect of the present invention is a method of everting a vessel. In this method, a tubular workpiece is provided. The tubular workpiece has a tube member having an inner lumen, an inner surface, an outer surface, a distal end, and a proximal end. An instrument for everting an end of a vessel over an end of a tubular workpiece is also provided. The instrument has a frame. There is a mandrel. The mandrel has a distal end and a proximal end. The mandrel is mounted to the frame and axially movable with respect thereto. The distal end of the mandrel is insertable into a lumen of a vessel. The instrument has a first wiping element having a first wiping face and an opposed second wiping element having a second wiping face. The first and second wiping elements mounted to the frame with the mandrel positioned therebetween. The first and second wiping elements being laterally movable from a spaced-apart position to a closed position. The mandrel is inserted into a lumen of a vessel for holding the vessel inside of the lumen of the tubular workpiece. Then, the first and second wiping elements are closed over the mandrel proximal to the end of the vessel. Next, the first and second wiping surfaces of said first and second wiping elements are wiped along the mandrel in the distal direction and over the tubular workpiece, thereby everting the end of the vessel over the distal end of the tubular workpiece. 
     Yet another aspect of the present invention is a system for everting a vessel. The system consists of the combination of the above-described evers ion instrument and tubular workpiece. 
     These and other aspects and advantages of the instruments and methods of the present invention will become more apparent from the following description and accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an eversion instrument  10  of the present invention; 
     FIG. 2 is a partial side view of the distal end of the eversion instrument  10  of FIG. 1, showing a first step of the operational sequence for everting a vessel  100  held in a tube  90 ; 
     FIG. 3 is a perspective view of the distal end of eversion instrument  10 , again showing the first step of the operational sequence for everting vessel  100  held in tube  90 ; 
     FIG. 4 is a side view of the distal end of eversion instrument  10 , showing a second step of the operational sequence for everting vessel  100 , wherein the distal vessel end  102  begins to evert over the distal end of tube  90 ; 
     FIG. 5 is a side view of the distal end of eversion instrument  10 , showing a third step of the operational sequence for everting vessel  100 , wherein distal vessel end  102  is seen to be everted; 
     FIG. 6 is a perspective view of the distal end of eversion instrument  10 , again showing the third step of the operational sequence for everting vessel  100 , wherein distal vessel end  102  is everted; 
     FIG. 7 is a perspective view of the distal end of eversion instrument  10 , showing a fourth step of the operational sequence for everting vessel  100 ; and 
     FIG. 8 is a perspective view illustrating distal vessel end  102  of vessel  100  everted over the distal end of tube  90 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The vessel eversion instrument of the present invention is illustrated in FIGS. 1-8. Referring first to FIG. 1, an eversion instrument  10  for everting an end  105  of a vessel is illustrated. Typically, the distal end  105  of the vessel  100  is everted using the instruments  10  and methods of the present invention, however, it is possible to also evert the proximal ends as well. A surgeon or an assistant may use eversion instrument  10 , for example, for everting an end of a harvested segment of the greater saphenous vein prior to its anastomosis to a coronary artery during a CABG procedure. Eversion instrument  10  is sized and constructed in order to be held and operated with a single hand. Eversion instrument  10  is seen to have a first arm  20 , an opposing, second arm  30 , and a centrally mounted, spring arm  70 . First arm  20  is seen to have member  28  having proximal end  22  and distal end  24 . A proximal end  22  of first arm  20  is joined to a proximal end  32  of second arm  30 , thus forming a handle  40 . The distal end  24  of first arm  20  attaches to a first paddle member  26 . The distal end  34  of second arm  30  attaches to a second paddle member  36 , so that first and second paddle members,  26  and  36 , are substantially opposite each other. First arm  20  and second arm  30  are preferably made of a stiff but spring-like material such as a semi-hardened stainless steel or a polycarbonate plastic, for example, so that first paddle member  26  and second paddle member  36  are normally sprung apart as shown in FIG.  1 . Spring arm  70  is relatively slender compared to first and second arms,  26  and  36 , and is made of a spring-like material such as a semi-hardened stainless steel or a rigid, flexible plastic such as high density polyethylene. Spring arm  70  has a proximal end  76  attached at handle  40  between first and second arms,  26  and  36  and a distal end  78 . The proximal end  84  of a mandrel  80  is mounted to distal end  78  such that mandrel  80  is positioned between first and second paddles,  26  and  36 . Mandrel  80  is seen to have a curved portion  86  that tapers to a distal tip  82 . Mandrel  80  is seen to have exterior surface  81 . Mandrel  80  is slender for insertion into the lumen of a vessel having an internal diameter approximately in the range of 3-5 mm. Mandrel  80  is made of a resiliently stiff biocompatible material such as, for example, high density polyethylene, so that when mandrel  80  is inserted into a rigid wall tube having an internal diameter approximately in the range of 3-5 mm, curved portion  86  of mandrel  80  is at least partially straightened. In the embodiment of the present invention shown in FIG. 1, mandrel  80  is an extension of spring arm  70 . Eversion instrument  10  is further seen to have a first wiping element  50  mounted on first paddle member  26  and a second wiping element  60  mounted on second paddle member  36 . First wiping element  50  is seen to have a wiping surface  51 , and second wiping element  60  is seen to have a wiping surface  61 . First and second wiping elements,  50  and  60 , may be made of any one of a number of resilient, soft materials such as the following, although not limited to these materials: foam rubber, cloth, cotton gauze pads, multi-layers of facial tissues, plastic bag pouches sealed with enclosed air or gel, and low durometer elastomers such as latex rubber. First wiping element  50  is mounted to first paddle  26  and second wiping element  60  is mounted to second paddle  36  preferably with an adhesive, although numerous other conventional attachment methods will be apparent to those skilled in the art, including mechanical fasteners, welding, friction fits, etc. and the like and equivalents thereof. When an operator squeezes together first arm  20  and second arm  30  such that arms  20  and  30  are moved to a position closer to each other, first wiping element  50  and second wiping element  60  come together with the surfaces  51  and  61  substantially in contact with each other and with exterior surface  81  of mandrel  80 , wherein mandrel  80  is located in-between, and with a force proportional to the squeezing force applied by the operator. 
     The steps for the method of use of eversion instrument  10  are now described according to the operational sequence depicted in FIGS. 2 through 7. Referring initially to FIG. 2, the first step of the operational sequence is inserting mandrel  80  into a vessel  100  that is held in a tube  90 . Vessel  100  may be a portion of the greater saphenous vein harvested from a surgical patient, as already noted, or also may be a portion of another blood vessel or hollow organ in the body. Vessel  100  is seen to have distal end  102 , interior lumen  105 , exterior surface  107  and interior surface  109 . Tube  90  may be a bushing, ferrule, anastomotic coupler, or a portion of an anastomotic fastener applier or delivery device, for example. Tube  90  is seen to have lumen  91 , exterior surface  99 , interior surface  93 , and distal end  98 . During the steps of the operational sequence, the operator, an assistant, or a holding device holds tube  90 . The operator inserts vessel  100  into the lumen of tube  90  so that a distal vessel portion  102  of vessel  100  extends beyond an open distal end  98  of tube  90 . The length of distal vessel portion  102  may vary depending on the requirements of the particular anastomostic technique associated with tube  90 , and will be sufficient to provide for an effective eversion, but generally the length of distal vessel portion  102  is approximately in the range of 5-15 mm. During this first step the operator may squeeze together first paddle  26  member (see FIG. 1) and second paddle member  36  in order to facilitate insertion of distal tip  82  of mandrel  80  into lumen  105  of vessel  100 . Curved portion  86  of mandrel  80  partially straightens during insertion into lumen  105  of vessel  100 , which is constrained within the lumen  91  of tube  90 , establishing a first contact  92 , a second contact  94 , and a third contact  96 , between the exterior surface  81  of mandrel  80  and the interior surface  109  of vessel  100 . Because mandrel  80  is made of flexibly resilient material, mandrel  80  straightens easily during insertion into vessel  100 , yet has sufficient spring-back to provide a gentle holding force on vessel  100  against the interior surface  109  of tube  90 , thus helping to prevent vessel  100  from receding further into tube  90  during the next steps of the operational sequence. Also, because spring arm  70  easily bends when force is applied to mandrel  80 , the allowable insertion force of mandrel  80  into vessel  100  is limited, thus helping to prevent injury to vessel  100 . The operator inserts mandrel  80  into vessel  100  at least far enough, to establish first, second, and third contact points,  92 ,  94 , and  96 . 
     FIG. 3 is a perspective view of a portion of eversion instrument  10  for the first step of the operational sequence shown also in FIG.  2 . Mandrel  80 , attached to spring arm  70 , is shown inserted into vessel  100 , which is held in tube  90 . The operator squeezes together first arm  20  and second arm  30 , bringing first wiping element  50  and second wiping element  60  together in a closed position around mandrel  80 . 
     Now referring to FIGS. 4 and 5, a second step of the operational sequence is the eversion of end  102  of vessel  100 . The operator holds together first paddle  26  (see FIG. 1) and second paddle  36  while advancing them towards tube  90 . Consequently, the surfaces  51  and  61  of first wiping element  50  and second wiping element  60  (see FIG. 3) wipe along mandrel  80  and cause end  102  of vessel  100  to “accordion” or gather as shown in FIG.  4 . During this second step, distal tip  82  of mandrel  80  may move slightly further into the lumen of tube  90 , without adverse consequence. The operator continues this wiping motion of first and second paddles,  26  (hidden) and  36 , as shown in FIG. 5 in order to completely evert end  102  of vessel  100  over the end  98  of tube  90  and onto tube exterior surface  99 . 
     FIG. 6 is a perspective view of a portion of eversion instrument  10 , showing the completion of step  2  also shown in FIG.  5 . In FIG. 6, first wiping element  50  and second wiping element  60  are shown conforming around the outside of tube  90  and everted vessel end  102  while first arm  20  and second arm  30  are held together. Mandrel  80  remains inside of vessel  100 , but spring arm  70  deflects, thus preventing the operator from inadvertently forcing mandrel  80  further into lumen  105  of vessel  100  and possibly injuring vessel  100 . 
     FIG. 7 shows a third step of the operational sequence. The operator releases first arm  20  and second arm  30  to allow first wiping element  50  and second wiping element  60  to move to a spaced apart position. If vessel  100  is not properly everted over the end  98  of tube  90 , the operator may repeat the second and third steps shown in FIGS. 4-7. The operator may initially apply only a very light squeezing force to first and second arms,  20  and  30 , to minimize trauma to vessel  100 , gradually increasing this force with each subsequent wiping motion. The operator then withdraws mandrel  80  from vessel  100 , pulling back on spring arm  70  if necessary. FIG. 8 is a perspective view of vessel  100  everted over tube  90 , after mandrel  80  has been removed. 
     Those skilled in the art will envision other types of handles and arms than the present embodiment for positioning wiping elements  50  and  60  as described herein. Furthermore, wiping elements  50  and  60  may be disposable and detachable from eversion instrument  10  for quick and easy replacement during a surgical procedure, or for resterilization of the handle and use on another patient. 
     The following example is illustrative of the principles and practice of the present invention, although not limited thereto. 
     EXAMPLE 
     A patient undergoing cardiac coronary artery bypass graft (CABG) surgery is prepared for surgery and anesthetized in a conventional manner in accordance with the prevailing medical standards. The patient&#39;s chest is opened in a conventional manner by cutting through the sternum and expanding the rib cage with a conventional surgical retractor instrument. The patient&#39;s heart is accessed in a conventional manner and the patient is connected to a pulmonary bypass machine and the heart is stopped. A section of the patient&#39;s saphenous vein, which has already been harvested by this time, is prepared for use as a graft vessel. The graft vessel end that is to be attached to the aorta for the proximal anastomosis is everted using an eversion instrument of the present invention as already described in the detailed description and shown in FIGS. 2-6. In FIG. 6, vessel  80  is shown everted over tube  90 . One embodiment of tube  90  is disclosed in published patent application WO0056228, “Low Profile Anastomosis Connector”, filed on Mar. 20, 2000, assigned to By-Pass, Inc., and which is hereby incorporated herein by reference. As described in WO0056228, a metallic anastomosis connector comprising a plurality of ring segments is used to fasten the graft vessel to another vessel such as the aorta. The distal end of the graft vessel is then be anastomotically attached to a coronary artery on the heart using a conventional hand suturing method. Additional bypasses are performed in the same manner or variations, depending on the patient&#39;s condition and anatomy. The remainder of the CABG procedure is conducted in a conventional manner and includes the steps of inspecting and repairing the grafts for leaks, checking blood flow, removing the patient from the pulmonary bypass machine, and closing the surgical incision. 
     The eversion instruments and eversion methods of the present invention have many advantages. The present invention is less traumatic to the intima of the vessel during the eversion procedure than conventional surgical graspers and the like. The present invention is easy for the surgeon to use without assistance and requires only a few steps to operate. The present invention is useful for a wide range of blood vessel sizes, particularly small vessels, e.g., having a diameter of about 2-3 mm or less. In addition, the present invention is useful on one end of a vessel, when the opposite end is already attached to the patient (e.g., at the distal anastomosis of a patient undergoing a CABG procedure). The present invention also allows for the proper length of everted tissue over the tube, bushing, or the like, depending on the requirements of the anastomosis device or method being used. Finally, the present invention may be manufactured inexpensively. 
     Accordingly, there is a need in this art for novel devices and methods for engaging and everting the end of a blood vessel (or other tubular body organ) over a member such as a tube, ferrule, bushing, or the like which can be used in a quick and effective manner without causing trauma to the vessel or the intima of the vessel (or tubular body organ). 
     Although this invention has been shown and described with respect to detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and scope of the claimed invention.