Abstract:
An anvil assembly is described. The anvil assembly includes including an axis with a proximal and a distal portion, an anvil associated to the distal portion of the axis formed by a central portion and at least a remote rotating portion and a system for reducing the encumbrance of the assembly of the anvil and relative restoring of such encumbrance. This is possible thanks to a half-automatic system specifically activated by the user of the surgical instrument and/or by an automatic system integrated in the system for opening and closing the surgical instrument without the need of activating any specific mechanism. The reduction and the restoring of the anvil size is an advantage during the insertion and the removal of the anvil into and from the organ of the patient.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention has as subject an anvil assembly for a surgical stapler of the type suitable for applying fasteners in a tissue. 
         [0002]    More specifically, the invention relates to a stapler of circular type, in particular suitable to be used in a hollow organ for implementing anastomosis. 
       BACKGROUND 
       [0003]    In the art several types of surgical instruments for applying suturing elements to a tissue are known, in particular for inserting so-called “fasteners”. The suturing of two extracts or fragments of tissue by means of the latter is performed by means of devices known as staplers. 
         [0004]    The surgical staplers generally comprise a cartridge suitable to eject one or more fastener and a so-called “anvil”, or contrast, arranged on the opposite side of the tissue to be sutured with respect to the cartridge. The fasteners indeed abut against the anvil to implement the suture. Upon use, then, the surgeon arranges the two portions of the tissue to be sutured between the cartridge and the anvil and drives the instrument to eject the fasteners, thus determining the penetration of the latter into the two portions of the tissue to be joined. 
         [0005]    Both so-called linear staplers, applying one or more rows of fasteners, and so-called circular staplers, applying one or more concentric lines of fasteners, are known. The circular staplers are particularly suitable to be used for the anastomosis of tubular hollow organs, and specifically the intestine and the oesophagus. 
         [0006]    In a rather common surgical procedure, known as “end-to-end anastomosis”, after the removal of a intestine tract (needed in case of pathological conditions such as for example a tumour), the remaining intestine ends are joined by using a circular stapler. To this purpose, a fragment of intestine is fastened to the anvil and the other fragment is kept around the cartridge. At this point the anvil is brought near the cartridge, by acting on a knob for closing the stapler. When cartridge and anvil abut one onto the other one, the fasteners are ejected, by penetrating the fragments of tissue and by abutting onto the anvil. During such procedure, generally a circular blade eliminates the superfluous tissue exceeding at the suturing line, by guaranteeing a suitable passage opening and by also allowing the surgeon to check the suturing efficiency. The anvil acts as abutment/end-stroke means even for such blade. 
         [0007]    A similar procedure is performed even in the treatment of haemorrhoids, wherein the removal of a whole tract of intestine and therefore the formation of two fragments is not provided, on the contrary the removal of the rectal mucous tissue and the restoring of a passage opening are provided. Even in this case the exceeding tissue is kept between the anvil and the cartridge of a circular stapler and a blade performs the removal of the exceeding tissue simultaneously to the suturing of the remaining portions. 
         [0008]    The two types of just described interventions, that is with and without formation of intestine fragments, are schematically shown in  FIGS. 1A and 1B . 
         [0009]    A drawback of the just described known circular staplers is that the anvil, during the instrument extraction, can meet a certain resistance at the level of suturing line bearing the fasteners. Any forcing during such extraction risks of compromising the integrity of the suturing, which has just been performed and thus results to be more vulnerable. On the contrary, performing a cut nearest to the suturing line in order to obtain a wider passage necessarily makes the sutured region less resistant. 
         [0010]    Similar drawbacks can be also found even upon inserting the anvil into the hollow organ or however into the region to be sutured. 
         [0011]    A possible solution to facilitate the removal of the stapler after the intervention is provided in U.S. Pat. No. 4,505,272, describing an instrument which can be reduced into four portions. However, the structure of the proposed stapler results to be rather complex and expensive to be produced. 
         [0012]    An additional solution is subject of US 2012/0234890. In such case, the base of the anvil is formed by height revolving planar segments, allowing the anvil itself to assume an expanded configuration and a configuration of reduced encumbrance. However, the plurality of joints of such structure can result to be complex. 
       SUMMARY OF THE INVENTION 
       [0013]    The technical problem placed and solved by the present invention is then to provide an anvil assembly and a relative surgical stapler, in particular of circular type, allowing to obviate the drawbacks mentioned above with reference to the known art. 
         [0014]    Such problem is solved by an assembly for surgical stapler according to claim  1  and by a stapler according to claim  14 . 
         [0015]    Preferred features of the present invention are subject of the depending claims. 
         [0016]    In the present context the terms “distal” and “proximal” will be used according to the common use in the field to designate portions respectively farer than, or nearer to, a user in the described configuration. 
         [0017]    The anvil assembly of the invention can be inserted and/or removed from the surgical site in a configuration of minimal encumbrance and therefore without compromising the safety of the surgical intervention and the health of the patient. 
         [0018]    Furthermore, the anvil assembly of the invention and the stapler wherein it is inserted are suitable to an easy and inexpensive production, with a simple and then intrinsically reliable mechanical structure. 
         [0019]    The stapler of the invention is particularly suitable for procedures of anastomosis in hollow organs and in case of haemorrhoids or intestinal prolapse (so-called PPH interventions—Procedure for Prolapse and Hemorrhoids). 
         [0020]    The main advantage of the invention consists in facilitating and making atraumatic the insertion of the instrument, especially when the proximal intestinal segment to be anastomosed has a smaller size than the distal segment, typical event in the colorectal anastomoses. 
         [0021]    In particular, the invention provides an anvil assembly for surgical stapler bearing a main body and a pair of winglet-like revolving portions, suitable to close onto the main body to assume the above-mentioned configuration of minimal encumbrance. In the open configuration, the anvil assembly, instead, has its maximum encumbrance and it can act efficiently as abutment means of the fasteners and of the blade during the suturing procedure. 
         [0022]    The winglet-like portions are directly hinged onto the main body, the latter bearing a distal profile for the penetration into an organ or tissue which is point-shaped. 
         [0023]    In an advantageous embodiment a mechanism for driving the above-mentioned revolving portions is provided, based upon a contrast spring or upon an equivalent elastically deformable element, able to exert an opening stress on such portions. 
         [0024]    Other advantages, features and use modes of the present invention will result evident from the following detailed description of some embodiments, shown by way of example and not for limitative purposes. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0025]    The figures of the enclosed drawings will be referred to, wherein: 
           [0026]      FIGS. 1A and 1B , already shown above, illustrate schematically a surgical procedure of anastomosis in a hollow tubular cable, in particular the intestine or oesophagus, and a procedure for suturing haemorrhoids, respectively; 
           [0027]      FIG. 2  shows a perspective view of a first preferred embodiment of the anvil assembly of the present invention, in a operative suturing configuration wherein it is comprised in a circular surgical stapler; 
           [0028]      FIG. 2A  shows an enlarged view of a portion of the assembly of  FIG. 2 ; 
           [0029]      FIG. 3  shows a perspective view of the anvil assembly of  FIG. 2  in a configuration of minimal encumbrance; 
           [0030]      FIG. 4  shows an exploded view of the anvil assembly of  FIG. 2 ; 
           [0031]      FIG. 5  shows another exploded view of the anvil assembly of  FIG. 2 , wherein even additional components are represented with respect to those of  FIG. 4 ; 
           [0032]      FIGS. 6A and 6B  show each one a view in longitudinal section of the anvil assembly of  FIG. 2 , in the configuration of minimal encumbrance and in the suturing operative configuration, respectively; 
           [0033]      FIG. 7  shows a perspective view of a second preferred embodiment of the anvil assembly of the present invention, in a configuration of minimal encumbrance; 
           [0034]      FIG. 8  shows an exploded view of the anvil assembly of  FIG. 7 ; 
           [0035]      FIG. 9  shows a perspective view of a third preferred embodiment of the anvil assembly of the present invention, in a configuration of minimal encumbrance; 
           [0036]      FIG. 10  shows an exploded view of the anvil assembly of  FIG. 9 ; and 
           [0037]      FIGS. 11A and 11B  show a side view an a view in longitudinal section, respectively, of the anvil assembly of  FIG. 9 , in an intermediated configuration between the one of minimal encumbrance and the suturing operative one. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0038]    Several embodiments and variants of the invention will be described hereinafter and this with reference to the above shown figures. 
         [0039]    Analogous components are designated in the several figures with the same reference numeral. 
         [0040]    In the following detailed description, additional embodiments and variants, with respect to embodiments and variants already treated in the same description, will be illustrated only in the differences with respect to what already illustrated. 
         [0041]    Furthermore, the different embodiments and variants described hereinafter are subjected to be used in combination, where they are compatible. 
         [0042]    By firstly referring to  FIGS. 2 and 2A , a surgical stapler of circular type according to a preferred embodiment of the invention is designated as a whole with  100 . The stapler  100  is suitable in applying suturing fasteners to a tissue, in particular a hollow organ for performing anastomosis or for removing portions of the tissue itself, in particular haemorrhoids. 
         [0043]    The stapler  100  comprises an anvil assembly according to a first preferred embodiment of the invention, designated as a whole with  1 . 
         [0044]    The stapler  100  also comprises a cartridge  101 , apt for ejection of the fasteners for their penetration into the tissue. 
         [0045]    As in the known staplers, the overall arrangement is such that the anvil assembly  1  and the cartridge  101  are suitable to assume a suturing operative configuration, shown in  FIGS. 2 and 2A , wherein they are brought near and in particular they abut one onto the other one. In such configuration, the anvil assembly  1  acts as contrast/abutment in the applying of fasteners into the tissue and even as end-stroke means for a cutting blade, indeed as already illustrated in the introduction with reference to the known systems. 
         [0046]    By also referring to  FIGS. 3 ,  4  and  5 , the anvil assembly  1  comprises an anvil-like main body  2 . In the present embodiment, such main body  2  has a distal profile  20  for the insertion into an organ which is substantially shaped like an arrow point or however pointed. 
         [0047]    The main body  2  has a longitudinal axis L even defining a longitudinal axis of the assembly  1  and of the cartridge  101 . 
         [0048]    The main body  2  comprises a pair of portions  21  and  22  projecting proximally and substantially shaped like a fixed winglet. In the present example, the projecting portions  21  and  22  are arranged on transversally opposed portions with respect to the longitudinal axis L. 
         [0049]    The main body  2  is integral to a stem or shaft  5 , extending proximally too and substantially according to the longitudinal axis L. 
         [0050]    A pair of winglets, respectively  31  and  32 , is connected to the main body  2 , mobile with respect to the main body. Advantageously, each winglet  31 ,  32  is rotatably connected directly to the main body  2 . In particular, each winglet  31 ,  32  has a rotational freedom degree with respect to the main body  2  according to a rotation axis which, in the present example, is orthogonal or substantially orthogonal to the longitudinal axis L and, generally, to the insertion direction of the anvil assembly  1  in the patient body. 
         [0051]    The above-mentioned revolving connection can be implemented by means of connection means known on itself. In particular, in the present example a flange  311 ,  321  is provided, integral to each winglet and one or more respective pins (one of which represented by way of example in  FIG. 5  and designated with  60 ) associated to the main body  2  and received each one in a suitable seat of a respective flange  311 ,  312 . The longitudinal axis of such or each pin defines the rotation axis of the respective winglet. 
         [0052]    Preferably, the configuration is such that said or each winglet  31 ,  32  has a rotation interval of about 90 degrees. 
         [0053]    Still in the present example, the winglets  31  and  32  are arranged on transversally opposite sides of the main body  2  with respect to the longitudinal axis L, so that a fixed winglet  21 ,  22  is alternated to a revolving winglet  31 ,  32  along the cross section of the main body  2 , that is on the cross periphery of the main body. 
         [0054]    As it is better appreciated from the comparison between  FIG. 2A  and  FIG. 3 , the rotating capability of the winglets  31  and  32  makes that the assembly  1  can assume a first configuration of minimal encumbrance, shown in  FIG. 3 , wherein the winglets  31  and  32  are rotated inwards, that is towards the longitudinal axis L and therefore in the proximal direction, and a suturing operative configuration, shown in  FIG. 2A , wherein the winglets  31  and  32  are rotated outwardly, that is deployed in the distal direction, and suitable to abut onto the cartridge  101 . 
         [0055]    The end-stroke of the winglets  31  and  32  in the above-mentioned operative configuration can be defined by corresponding abutment surfaces of the main body  2 , one of which is designated with  23  in  FIG. 4  by way of example. 
         [0056]    The anvil assembly  1  comprises then means for driving the mobile winglets  31  and  32 , apt to cause the passage from said configuration of minimal encumbrance to said operative configuration and viceversa, which means is designated as a whole with  4 . 
         [0057]    In the present advantageous embodiment, the diving means  4  is based upon a coupling between the winglets  31  and  32  and an elastic contrast means, in particular a compression helical spring  44  arranged coaxially to the stem  5 . 
         [0058]    Such coupling is obtained by means of shaped driving elements  41  and  42 , preferably with elongated shape. Each element  41 ,  42  is connected at a first end thereof to a respective winglet  31 ,  32  and at the other end to the helicoidal spring  44 . To this purpose, seats or connection elements  24  for the driving elements  41  and  42  are obtained on the winglets  31  and  32 . 
         [0059]    Still in the present arrangement, the above-mentioned connections between the ends of the driving elements  41  and  42  and the respective winglets  31  and  32  and the contrast element  44  are revolving connections implemented, for example, by means of small pins, one thereof designated by way of example with  45  in  FIG. 3 . 
         [0060]    In the present example, each driving means  41 ,  42  is substantially shaped like a stem with longitudinal profile having one or more loops. 
         [0061]    Still in the present embodiment, the driving means  41  and  42  are connected to the elastic contrast element  44  by means of interposing a ring  43 . The latter is substantially arranged centred on the longitudinal axis L. Therefore, the loop-like profile of the driving means  41  and  42  allows the latter to project laterally outwardly with respect to the longitudinal axis L. 
         [0062]    The ring  43 , in turn, is fastened at an arm or a distal turn of the compression spring  44 . 
         [0063]    With reference also to  FIGS. 6A and 6B , in the herein described embodiment the spring  44  is kept between the winglets  31  and  32  and an abutment surface  40  obtained inside the cartridge  101 . 
         [0064]    Inside the cartridge  101  a sliding seat  50  for the stem  5  is also obtained, indeed guiding the latter in a substantially translatory motion along the direction of the longitudinal axis L. 
         [0065]    Upon making the stem  5  to slide within the seat  50  in proximal direction—that is by pulling the stem  5  towards the user in the direction of the arrow F of FIG.  6 A—the main body  2  and the mobile winglets  31  and  32  associated thereto slide integrally to the stem itself. When the proximal end of the spring  44  abuts onto the abutment surface  40 , the additional sliding of the stem  5  produces a compression of the spring itself, which then exerts a contrast action on the winglets  31  and  32  by means of the driving means  41  and  42  connected thereto. Such contrast action makes that the driving means  41  and  42  force the winglets  31  and  32  to open outwardly, by reaching the maximum opening with end-stroke means on the surfaces  23  of the main body  2 . 
         [0066]    In such motion bringing the mobile winglets  31  and  32  to deploy, the driving means  41  and  42  act then each one like a kind of connecting rod. In fact, the longitudinal ends of each element  41 ,  42  are connected to a sliding element (the spring  44 ) and to a revolving element (the respective winglet  31 ,  32 ), respectively. 
         [0067]    Simultaneously or shortly after reaching the above-mentioned deployed configuration, the main body  2  abuts onto the cartridge  101  to carry out its own anvil function with respect to the fasteners ejected by the cartridge itself. Such operative configuration is shown in  FIG. 6B . 
         [0068]    Of course, the opposite motion of the stem, that is the sliding thereof in the distal direction, produces the restoration of the configuration of minimal encumbrance shown in  FIG. 6A . 
         [0069]    The sliding of the stem  5  according to the above-mentioned modes can be activated manually by the surgeon by acting on a control or knob  400  of the stapler  100 . Such control or knob  400  is shown schematically in  FIG. 2  and preferably arranged at a handle portion of the stapler itself. 
         [0070]    Alternatively or in association with the manual activation, automatic activation means of the stem  5  can be provided, apt to control the passing of the anvil assembly  1  from the configuration of minimal encumbrance to the operative configuration and/or viceversa. Preferably, such automatic activation is obtained depending upon the relative position, brought near or remote, of the anvil assembly  1  with respect to the cartridge  101 . In particular, the closure of the winglets  31  and  32  can be controlled automatically when the main body  2  is moved away from the cartridge  101 . Similarly, the opening of the winglets  31  and  32  can be activated automatically when the user brings the main body  2  near the cartridge  101 . 
         [0071]    Embodiment variants can provide a different arrangement of portions and in particular an elastically deformable means, different from the above-considered spring. 
         [0072]    An embodiment variant can further provide that the driving means bases upon a positive coupling between the winglets  31  and  32  and the respective driving elements  41  and  42 . In particular, respective cam-like surfaces or profiles can be obtained on the winglets, arranged at an inner face of the winglet, that is the face directed towards the longitudinal axis L. The engagement of such surfaces by the respective driving elements  41 ,  42  moved in the distal direction determines the opening out of the winglets  31  and  32  themselves. 
         [0073]    In such case, then, the described positive coupling allows transforming the longitudinal motion of the stem  5  into the revolution one of the winglets  31  and  32 . 
         [0074]    An additional variant can even provide one single portion like a mobile winglet instead of the pair of the above described winglets. 
         [0075]    Going back to  FIG. 5 , two acknowledgment or feedback elements are represented, designated with  61  and  62 , respectively, and preferably made of plastic. Each one of the feedback elements  61 ,  62  is integral to the main body  2  and arranged on the latter at an inner face of a respective mobile winglet  31 ,  32 . Each feedback element  61 ,  62  is suitable indeed to provide a (in particular auditory) acknowledgment of carried-out cut after driving the blade of the stapler (which blade is not represented in the figures, being known on itself). 
         [0076]    Even these elements are already known in the art and thus will not further dwell upon the description thereof. 
         [0077]      FIG. 5  also shows a retaining element  333 , with elongated shape. It is suitable to be inserted in a hole  334  of the stem  5  and prevents the spring  44  from falling into the instrument by moving away from the main body  2 , when the latter is far from the cartridge  101  and the spring  44  is released. Such element then acts as proximal acknowledgment or end-stroke means for the spring itself. 
         [0078]      FIGS. 7 and 8  refer to a second preferred embodiment of the anvil assembly of the invention, herein designated as a whole with  10 . 
         [0079]    With respect to the already described first embodiment and related variants, the herein considered assembly is removable with respect to the remaining portion of the stapler. To this purpose, the anvil assembly  10  indeed has means for the removable connection to the surgical stapler, designated as a whole with  7  and arranged at the stem, herein designated with  500 . 
         [0080]    In the represented exemplifying arrangement, the stem  500  is implemented in three portions,  501 ,  502  and  503  respectively. The first portion  501 , or distal portion, is integral to the main body  2  of the anvil assembly  10 . The second portion  502  is an intermediate portion for the connection of the distal portion  501  to the third proximal portion  503 , the latter associated to the remaining portion of the surgical stapler. The three portions  501 ,  502  and  503  are made removably integral one to the other one by means of quick engagement or equivalent means, in case based upon different types of shape coupling. 
         [0081]    In particular, the coupling shown in  FIG. 8  includes two bending elements  504 , for example substantially shaped like a winglet. Such elements  504  are stiff in the distal portion thereof and flexible in the proximal portion thereof. This flexibility allows the elements  504  to engage the third proximal portion  503 , by hooking it to the intermediate portion  502  and by keeping it integral to the latter as long as a force higher than the resistance of the elements  504  is not applied to the means  7  in order to release the two portions  501  and  502  from the proximal portion  503 . In the present example, even the portions  501  and  502  engage removably one in the other one. 
         [0082]      FIGS. 9 to 11  B refer to a third preferred embodiment of the anvil assembly of the invention, herein designated as a whole with  11 . 
         [0083]    With respect to the preceding embodiments and variants, the anvil assembly  11  does not provide any contrast element and the activation of the driving means  41  and  42  is only manual. To this purpose, a shaft  8  is provided thereto a ring  430  is made integral. The latter is arranged coaxially on the stem of the anvil assembly  11 , which stem is designated with  51 . The ring  430  guides a sliding motion of the shaft  8  on the stem  51  itself. The latter has also a proximal end-stroke means  52  for the ring  430 , preferably in the form of an abutment surface, in this case an annular surface. 
         [0084]    An elongated guiding element  81  is made integral, distally, to the shaft  8 , which element is sliding within a longitudinal slot  53  of the stem  51 , integrally to the shaft  8 . 
         [0085]    At opposed cross ends of the element  81 , in particular on opposite sides with respect to the stem  51 , the already shown driving means  41  and  42  are connected on the element  81  itself. 
         [0086]    The operating modes of the assembly  11  for the rest can be analogous to the ones already described above with reference to the previous embodiment and related variants. 
         [0087]    The present invention has been sofar described with reference to preferred embodiments. It is to be meant that other embodiments belonging to the same inventive core may exist, as defined by the protection scope of the herein below reported claims.