Abstract:
An anastomosis system includes a base, two rings, and a blood vessel-leading unit. A first blood vessel can be inserted in and attached to the first ring by the blood vessel-leading unit. A second blood vessel can be inserted in and attached to the second ring by the blood vessel-leading unit. The first ring is placed on a ring-guiding base in a specific manner. The second ring is placed on the ring-guiding base in a movable and rotatable manner to assure the alignment of the blood vessels in both axial and angular directions. The two rings are interconnected by at least one snap-on mechanism or buckle so that the interconnection of the rings is efficient.

Description:
CROSS-REFERENCE 
       [0001]    The present application is a continuation-in-part application of U.S. patent application Ser. No. 12/698,477 of which the entire disclosure is incorporated herein for reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention generally relates to an anastomosis system and, more particularly, to an effective and efficient micro-vascular anastomosis system for joining together two blood vessels without having to turning any one of the blood vessel inside out. 
         [0004]    2. Description of the Related Art 
         [0005]    Anastomosis of blood vessels is one of the greatest achievements in contemporary surgery which expands the surgical field to provide patients with better treatment. Surgical operations such as heart bypass surgery, solid-organ transplantation, radiocephalic fistula and micro-vascular free flap reconstruction are required to be finished with the anastomosis of blood vessels. As for micro-vascular free flap reconstruction, the anastomosis of blood vessels makes it possible for the patients with congenital anomalies, malignant tumor invasion, or injured-caused massive soft tissue defects to receive auto-graft to resurface the defects, and then improve function and appearance. 
         [0006]    The present procedure of micro-vascular anastomosis is mainly stitching by hand. However, the outcome of this traditional method for anastomosis of blood vessels relies on the skill and experience of a surgeon. It may therefore result in problems of taking long time, blood leakage from pinhole, and/or blood vessel occlusion caused by stitching opposite sides of the blood vessels or twisting the blood vessels. Hence, there have been quite a few studies for various anastomosis techniques to solve these problems. 
         [0007]    In general, there are two types of suture-less anastomosis techniques, one is by chemical and the other one is by physical bonding for tissue fixation. For the one by chemical bonding, it has been disclosed in many literatures to apply tissue glue or laser welding for the anastomosis of blood vessels. However, not any actual clinical applications have been developed from these types of methods because of their complicated and inconvenient operating procedures and the difficulty in maintaining a high patency. 
         [0008]    Current clinical implementations of micro-vascular anastomosis techniques are mainly mechanical bonding. Based on their fixation mechanism, these mechanical tissue fixation methods include: stapling, clamping, coupling by a ring-shaped anastomotic coupler. For stapling, a launcher shoots an anastomotic staple to pierce the two ends of blood vessels intended to be anastomosed, and then bends the staple to fix the tissues. For clamping, a vascular clip is applied to hold the two ends of blood vessels to be anastomosed in a non-piercing way. However, because it is difficult to maintain the stress distribution in the blood vessels uniformly, the blood vessels might easily be damaged by this method. To improve this, some ring-shaped couplers are developed in succession. 
         [0009]    The fixation mechanisms of a ring-shaped anastomotic coupler are similar to those of stapling and clamping methods. Among them, the “ring-pin” type coupler is a design using stapling as the fixation mechanism and the “SYNOVIS” GEM micro-vascular anastomotic coupler system (SYNOVIS MICRO COMPANIES ALLIANCE, INC. USA) is the only ring-pin type coupler currently on the market. The “extraluminal cuffing ring” is a coupler using clamping as tissue holding mechanism, which does not have any commercialized products yet. 
         [0010]    In comparison with the traditional hand-stitched method, the above-mentioned mechanical bonding methods indeed effectively reduce the operation time and the requirements in surgical skills of anastomosis. However, a common drawback of these methods is that the blood vessels have to be everted for 90 degrees or even 180 degrees in operation, which is not applicable to the blood vessels with atherosclerotic change and might cause blood vessel spasm due to tension at the anastomosis site or insufficient blood vessel length for eversion. This drawback has substantially restricted the implementation of these methods in micro-vascular anastomosis. These ring-shaped anastomotic couplers require a complicated staple launcher or alignment equipment which makes the system expensive. Furthermore, the anastomotic staple or ring-pin type anastomotic coupler fixed the tissue by piercing blood vessels, which inevitably damages the blood vessels. The adherence by tissue clips or extraluminal cuffing ring also may cause pressure necrosis of blood vessel walls. Because of the distinct material properties of the anastomotic couplers and the blood vessels, it is likely to cause local compliance mismatch of the blood vessels and disturb the transmission of pulse waves in blood circulation. 
         [0011]    As disclosed in U.S. Pat. No. 4,747,407, an anastomosis kit includes a male clamp  5   a  and a female clamp  5   b.  A doctor uses the male clamp  5   a  to clamp an anastomosis wheel  1  and uses the female clamp  5   b  to clamp another anastomosis wheel  1 . Then, the doctor moves the clamps  5   a  and  5   b  to each other to bring the anastomosis wheels  1  together. Almost the entire process for bringing the anastomosis wheels  1  together is not guided by any device. Only in a final phase, insertion of bolts  13   a  in holes  13   b  is used as means for alignment of the anastomosis wheels  1  with each other. It is however difficult to insert the bolts  13   a  in the holes  13   b  because they are small. As being movable relative to each other, the grooves  10  are useless for the alignment of the anastomosis wheels  1  with each other. Moreover, each of the anastomosis wheels  1  includes pins  4  that somehow limit the rotation of an anastomosis wheel  1  relative to the other anastomosis wheel  1  so that one of the blood vessels might be twisted. 
         [0012]    The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art. 
       SUMMARY OF THE INVENTION 
       [0013]    The primary objective of the present invention is to provide an effective and efficient anastomosis system. 
         [0014]    To achieve the foregoing objective, the anastomosis system includes a base, two rings, and a blood vessel-leading unit. A first blood vessel can be inserted in and attached to the first ring by the blood vessel-leading unit. A second blood vessel can be inserted in and attached to the second ring by the blood vessel-leading unit. The first ring is then rested on a ring-guiding base in a specific manner. The second ring is placed on the ring-guiding base in a movable and rotatable manner to assure the alignment of the blood vessels in both axial and angular directions. The two rings are interconnected by at least one snap-on mechanism or buckle. 
         [0015]    Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    All of the objects, advantages and features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings wherein: 
           [0017]      FIG. 1  is a cross-sectional view of a blood vessel-leading unit of an anastomosis system in accordance with a first embodiment of the present invention; 
           [0018]      FIG. 2  is a perspective view of two rings and a ring-guiding unit of the anastomosis system in accordance with the first embodiment of the present invention; 
           [0019]      FIG. 3  is a side view of the rings and the ring-guiding unit shown in  FIG. 2 ; 
           [0020]      FIG. 4  is a perspective view of the ring-guiding unit shown in  FIG. 2  and two rings of an anastomosis system in accordance with a second embodiment of the present invention; 
           [0021]      FIG. 5  is a cross-sectional view of the rings and the ring-guiding unit shown in  FIG. 4 ; 
           [0022]      FIG. 6  is a cross-sectional view of the first ring shown in  FIG. 5 ; 
           [0023]      FIG. 7  is a front view of the first ring shown in  FIG. 6 ; 
           [0024]      FIG. 8  is a cross-sectional view of the second ring and a ring-driving element of the ring-guiding unit shown in  FIG. 5 ; 
           [0025]      FIG. 9  is a front view of the second ring and the ring-driving element shown in  FIG. 8 ; 
           [0026]      FIG. 10  is a cross-sectional view of the blood vessel-leading unit shown in  FIG. 1  and the first ring shown in  FIG. 5 ; 
           [0027]      FIGS. 11 through 20  are cross-sectional views of a blood vessel in various positions relative to the first ring and the blood vessel-leading unit shown in  FIG. 10 ; 
           [0028]      FIGS. 21 through 30  are cross-sectional views of another blood vessel in various positions relative to the second ring and the blood vessel-leading unit shown in  FIG. 10 ; 
           [0029]      FIGS. 31 through 39  are cross-sectional views of the blood vessels and the rings in various positions relative to the ring-guiding unit shown in  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0030]    Referring to  FIGS. 1 through 3 , there is shown an anastomosis system in accordance with a first embodiment of the present invention. The anastomosis system includes a blood vessel-interconnecting unit  300 , a ring-guiding unit and a blood vessel-leading unit  100 . 
         [0031]    Referring to  FIG. 1 , the blood vessel-leading unit  100  includes a ring holder  101 , an elastic ring  102 , an indicator  103 , a knob  104 , an L-shaped balloon-driving element  105 , a balloon  106  and a tube  107 . The ring holder  101  is in the form of a cap. The ring holder  101  includes a cavity defined therein and a channel in communication with the cavity. 
         [0032]    The elastic ring  102  is placed in an annular groove defined in an internal face of the ring holder  101 . The elastic ring  102  is made of rubber or plastics for example. 
         [0033]    The indicator  103  is printed on or inscribed in a block fixed on the ring holder  101 . The indicator  103  is an arrow head or a line for example. The indicator  103  is used together with the marks A, B and C printed on or inscribed in the balloon-driving element  105  to indicate three positions for the balloon-driving element  105  and the balloon  106 . 
         [0034]    The knob  104  is placed rotationally on the ring holder  101 . The balloon-driving element  105  includes a first section extending through the knob  104  and a second section extending to the tube  107 . Although not shown, there is a mechanism between the knob  104  and the first section of the balloon-driving element  105  so that by rotating the knob  104 , the first section of the balloon-driving element  105  is moved forward or backward relative to the ring holder  101 . The mechanism, for example, may include a thread formed on an internal face of the knob  104  and engaged with another thread formed on the first section of the balloon-driving element  105 . 
         [0035]    The tube  107  is parallel to the first section of the balloon-driving element  105 . The tube  107  and the balloon-driving element  105  are preferably made one piece. The tube  107  movably extends through the channel and cavity of the ring holder  101 . The tube  107  is attached to the balloon  106  at an end and attached to a gas source such as a pump at another end so that the inflation and deflation of the balloon  106  can be well controlled. 
         [0036]    Referring to  FIGS. 2 and 3 , the ring-guiding unit includes a base  200  and a ring-driving element  201 . The base  200  is in the form of a trough. A boss  202  is formed on the bed of a groove  204  defined in the base  200 . That is, the boss  202  is formed on a concave upper face of the base  200 . The ring-driving element is in the form of a rod. 
         [0037]    The blood vessel-interconnecting unit  300  consists of two rings  310  and  320 . The ring  310  includes a lip  312  extending beyond an end and a recess  313  defined in an external face. The shape and size of the recess  313  are made corresponding to the boss  202 . The ring  320  includes a rib  322  formed thereon and a bore  323  defined in an external face. The rib  322  is shaped in compliance with the lip  312  to allow snap-on engagement after the alignment of the rings. The bore  323  is made corresponding to the ring-driving element  201 . In anastomosis, a blood vessel is attached to the first ring  310  after the former is guided into the latter by the blood vessel-leading unit  100 . Another blood vessel is attached to the second ring  320  after the former is guided into the latter by the blood vessel-leading unit  100 . The rings  310  and  320  are joined together after they are guided to each other by the ring-guiding unit. 
         [0038]    Referring to  FIGS. 4 and 5 , there is shown an anastomosis system in accordance with a second embodiment of the present invention. The second embodiment is like the first embodiment except including two ring sets  330  and  340  instead of the rings  310  and  320 . 
         [0039]    Referring to  FIGS. 6 and 7 , the ring set  330  includes a ring  331  and three buckles  334 . Each of the buckles  334  includes a first end pivotally connected to an end of the body  331  and a second end for engagement with an end of the ring set  340 . The ring  331  includes an annular groove  332  defined in another end and a recess  333  defined in an external face. The shape and size of the recess  333  are made corresponding to the boss  202 . 
         [0040]    Referring to  FIGS. 8 and 9 , the ring set  340  includes a ring  341 , an annular lip  342  extending from an end of the ring  341 , an annular groove  344  defined in another end of the ring  341 , and a bore  343  defined in an external face of the ring  341 . The bore  343  is made corresponding to the ring-driving element  201 . 
         [0041]    Referring to  FIG. 10 , there are shown the ring set  330  and the blood vessel-leading unit  100 . The indicator  103  is pointed at the mark A to set the balloon  106  in a retracted position. The balloon  106  is deflated. The ring  331  is then ready to be put into the ring holder  101 . 
         [0042]    Referring to  FIG. 11 , there is shown a blood vessel  401  in addition to the ring set  330  and the blood vessel-leading unit  100 . The ring  331  is placed partially in the ring holder  101  and held securely by the elastic ring  102 . By rotating the knob  104 , the indicator  103  is pointed at the mark B, and the balloon-driving element  105  and the balloon  106  are moved forward to pass through the ring  331  and access to the blood vessel  401 . 
         [0043]    Referring to  FIG. 12 , by rotating the knob  104 , the indicator  103  is pointed at the mark C, and the balloon-driving element  105  and the balloon  106  are moved forward further to allow the insertion of the balloon  106  into the lumen of the blood vessel  401  that is placed outside the ring  331 . 
         [0044]    Referring to  FIG. 13 , the balloon  106  is inflated to bring an external face thereof into contact with an internal face of the blood vessel  401 . The contact of the balloon  106  with the blood vessel  401  is firm and uniform so that the blood vessel wall is attached to the balloon well and they can be moved together. 
         [0045]    Referring to  FIG. 14 , some gas is ventilated from the balloon  106  to assure the external diameter of the balloon-supported blood vessel  401  is smaller than the internal diameter of the ring  331  before the balloon  106  is retracted to pass through the ring  331 . 
         [0046]    Referring to  FIG. 15 , by rotating the knob  104 , the balloon-driving element  105  and the balloon  106  are retracted and moved toward the ring  331 , and so is the blood vessel  401 . 
         [0047]    Referring to  FIG. 16 , the indicator  103  is pointed at the mark A. Now, the edge of the blood vessel  401  is aligned with the one end of the ring  331 . 
         [0048]    Referring to  FIG. 17 , the balloon  106  is further inflated to bring the blood vessel  401  into firm contact with the ring  331 . Means  337  is provided between the blood vessel  401  and the ring  331  to retain the blood vessel  401  to the ring  331 . The means  337  may be retention by bio-gel or by tiny needles for example. 
         [0049]    Referring to  FIG. 18 , the gas is exhausted from the balloon  106 . The balloon shrinks substantially and gets detached from the blood vessel  401 . 
         [0050]    Referring to  FIG. 19 , by operating the balloon-driving element  105 , the ring  331 , which is connected to the blood vessel  401 , is gently released from the ring holder  101 . 
         [0051]    Referring to  FIG. 20 , the blood vessel  401  is firmly attached to the ring  331  by the means  337 . 
         [0052]    Referring to  FIG. 21 , there is shown a blood vessel  402  together with the ring set  340  and the blood vessel-leading unit  100 . The indicator  103  is pointed at the mark B. The ring  341  is partially placed in the ring holder  101  and held securely by the elastic ring  102 . 
         [0053]    Referring to  FIG. 22 , by rotating the knob  104 , the indicator  103  is pointed at the mark C, and the balloon-driving element  105  and the balloon  106  are moved forward to allow the insertion of the balloon  106  into the lumen of the blood vessel  402  that is placed outside the ring  341 . 
         [0054]    Referring to  FIG. 23 , the balloon  106  is inflated to bring an external face thereof into contact with an internal face of the blood vessel  402 . The contact of the balloon  106  with the blood vessel  402  is firm and uniform so that the blood vessel wall is attached to the balloon well and they can be moved together. 
         [0055]    Referring to  FIG. 24 , some gas is ventilated from the balloon  106  to assure the external diameter of the balloon supported blood vessel  402  is smaller than an internal diameter of the ring  341  before the balloon  106  is retracted to pass through the ring  341 . 
         [0056]    Referring to  FIG. 25 , by rotating the knob  104 , the balloon-driving element  105  and the balloon  106  are retracted and moved toward the ring  341 , and so is the blood vessel  402 . 
         [0057]    Referring to  FIG. 26 , the indicator  103  is pointed at the mark A. Now, the edge of the blood vessel  402  is aligned with the one end of the ring  341 . 
         [0058]    Referring to  FIG. 27 , the balloon  106  is further inflated to bring the blood vessel  402  into firm contact with the ring  341 . Means  347  is provided between the blood vessel  402  and the ring  341  to retain the blood vessel  402  to the ring  341 . The means  347  may be bio-gel or tiny needles for example. 
         [0059]    Referring to  FIG. 28 , the gas is exhausted from the balloon  106 . The balloon shrinks substantially and gets detached from the blood vessel  402 . 
         [0060]    Referring to  FIG. 29 , by operating the balloon-driving element  105 , the ring  341 , which is connected to the blood vessel  402 , is gently released from the ring holder  101 . 
         [0061]    Referring to  FIG. 30 , the blood vessel  402  is firmly attached to the ring  341  by the means  347 . 
         [0062]    Referring to  FIG. 31 , the ring set  330  and the blood vessel  401  are moved toward the base  200 . 
         [0063]    Referring to  FIG. 32 , the ring set  330  and the blood vessel  401  are placed on the base  200 . The ring  331  is partially placed in the groove defined in the base  200 , with the boss  202  placed in the recess  333  to position the ring  331  on the base  200 . 
         [0064]    Referring to  FIG. 33 , the ring set  340  and the blood vessel  402  are placed on the base  200 . The ring  341  is partially placed in the groove defined in the base  200 . 
         [0065]    Referring to  FIG. 34 , the ring-driving element  201  is moved toward the ring  341 . 
         [0066]    Referring to  FIG. 35 , a lower end of the ring-driving element  201  is inserted in the bore  343  defined in the ring  341 . By operating the ring-driving element  201 , the ring  341  is rotated in the groove defined in the base  200 . 
         [0067]    Referring to  FIG. 36 , by operating the ring-driving element  201 , the ring  341  is moved toward the ring  331  in and along the groove defined in the base  200 . 
         [0068]    Referring to  FIG. 37 , by operating the ring-driving element  201 , the ring  341  is placed against the ring  331 . The annular lip  342  is placed in the annular groove  332 . Thus, the axis of the ring  341  is aligned with the axis of the ring  331 . 
         [0069]    Referring to  FIG. 38 , the ring-driving element  201  is detached from the ring  341 . 
         [0070]    Referring to  FIG. 39 , the buckles  334  are engaged with the ring  341 . The second end of each of the buckles  334  is inserted in the annular groove  344 . Hence, the ring sets  330  and  340  are firmly connected to each other, and so are the blood vessels  401  and  402 . 
         [0071]    The anastomosis system of the present invention exhibits several advantages over the prior art. At first, the insertion and fixation of the blood vessel  401  or  402  in the ring  331  or  341  is convenient because of the use of the blood vessel-leading unit  100  to drive the balloon  106  together with the blood vessel  401  or  402 . 
         [0072]    Secondly, the rotation of the ring  341  relative to the ring  331  is efficient because only the ring  341  is rotated on the base  200  while the ring  331  is not rotated because the boss  202  is placed in the recess  333  to position the ring  331  on the base  200 . 
         [0073]    Thirdly, the movement of the ring  341  relative to the ring  331  is efficient because only the ring  341  is moved on the base  200  while the ring  331  is not moved because the boss  202  is placed in the recess  333  to position the ring  331  on the base  200 . 
         [0074]    Fourthly, the rotation and movement of the ring  341  relative to the ring  331  are efficient because of the use of the ring-driving element  201  in the bore  343 . 
         [0075]    Fifthly, the alignment of the axis of the ring  341  to the axis of the ring  331  is precise because of the insertion of the annular lip  342  in the annular groove  332 . 
         [0076]    Sixthly, the interconnection of the rings  331  and  341  is efficient because of the use of the buckles. 
         [0077]    Seventhly, the interconnection of the rings  331  and  341  is effective because of the use of the annular groove  344  for receiving the second end of each of the buckles  334 . 
         [0078]    The present invention has been described via the detailed illustration of the preferred embodiment. Those skilled in the art can derive variations from the preferred embodiment without departing from the scope of the present invention. Therefore, the preferred embodiment shall not limit the scope of the present invention defined in the claims.