Abstract:
A rib retractor comprises a pair of L-shaped members able to be pivoted between an inserting and a working shape. Each lever comprises a detachable handle at a proximal side and a stretching jaw at a distal side. The members are linked at their respective corners by pivoting joining means. Each stretching jaw comprises a distal blade part and a curved section, acting as a cam to stretch apart the ribs when the retractor is brought from inserting to working shape and which define the operating field.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 60/160,186, filed Mar. 13, 2009, entitled “Rib Retractor,” which is hereby incorporated by reference in its entirety for all purposes. 
     
    
     BACKGROUND 
       [0002]    The invention relates to a device for moving apart the ribs of the thoracic cage in order to improve accessibility to internal organs of a patient, for example for thoracic and particularly heart surgery. 
         [0003]    A known procedure to move ribs apart comprises the following steps: making an incision between two ribs, inserting between the ribs a ring the diameter of which is larger than the intercostal space, then pulling on strips fastened to said ring, so as to pull the ribs apart. This method implies fastening the strips, which can be tedious. 
         [0004]    A device for providing the same function are known from U.S. Pat. No. 4,627,421. This document describes a retractor with pivoting arms. One arm is mounted on a teethed cross-bar and the other is mounted on a cursor that moves along the cross-bar. 
         [0005]    Other similar devices are described in WO 99/15081, US-2001/0041828, DE-3834358. 
         [0006]    All these devices are particularly aimed at classic thoracic surgery, meaning that the ribs are submitted to a strong pulling-apart force, and accordingly, less adapted to mini-invasive surgery. Mini-invasive surgery reduces to a minimum the wounds and bruises the body of the patient has to undergo and hence ensures a quicker recovery. 
       BRIEF SUMMARY 
       [0007]    It is an object of the invention to provide a rib retractor that would provide a good access to organs placed in the ribcage. 
         [0008]    Another object of the invention is to reduce as much as possible the strains exerted on the ribs. 
         [0009]    Still another object of the invention is to provide a rib retractor of reduced cumbersomeness and easy to use. 
         [0010]    The subject of the invention is a rib retractor which comprises two members extending from a proximal to a distal side. Each member comprises a stretching jaw and a handle. The stretching jaw is placed at the distal side and comprises:
       a substantially flat blade section having a free end and an opposite end, which is permanently connected to   a curved section extending substantially normal to the blade section, the convexity of said curved section directed towards the free end of the blade section.   The handle is detachably connected to the proximal side of the curved section of the stretching jaw and extends normal to the blade thereof, prolonging the curved section.       
 
         [0014]    The two members are pivotally connectable between an inserting and a working position. In the inserting position, the two blades of the stretching jaws are substantially in contact with and facing each other, allowing insertion thereof between two ribs. In the working position, the curved sections of the jaws face each other, defining an operating field. The curved sections of the jaws provoke, upon pivoting of the members from the inserting to the working position, a cam effect, thus pushing the ribs apart. 
         [0015]    According to an advantageous embodiment, the two members are pivotally connected by detachable ball-and socket joint means placed on either sides of the concave side of the curved sections of the jaws. 
         [0016]    According to an advantageous embodiment, the two members are pivotally connected by detachable mutually engaging gearings placed on either sides of the concave side of the curved sections of the jaws. 
         [0017]    Each curved central part is preferably provided at both lateral sides with a sheath, the corresponding sheaths of each central part lying parallel to each other when the rib retractor is in working position. 
         [0018]    According to an advantageous embodiment, U-form securing bridges able to be inserted in the corresponding sheaths of each central part so as to lock them in working position are provided. These U-form securing bridges preferably comprise support means for securing other medical devices, tubes, sutures and so on. 
         [0019]    Advantageously, the rib retractor comprises a screw extension device comprising a threaded rod and two members able to be moved relative to each other along said threaded rod, each of these members being able to be inserted into the corresponding sheaths on at least one side of each central part so as to pull them apart. Bridges of various lengths are then provided. 
         [0020]    According to another embodiment, the rib retractor comprises a ratchet extension device comprising a toothed rod and two members able to be moved relative to each other along said toothed rod, each of these members being able to be inserted into the corresponding sheaths on at least one side of each central part so as to pull them apart. 
         [0021]    The curved sections preferably have an U-shaped cross-section, the open side of the U being directed opposite to the free end of the substantially flat blade section. 
         [0022]    The handles and the stretching jaw are advantageously linked by mortice and tenon joint means. 
         [0023]    The members are made preferably out of polymer materials, and are advantageously disposable. 
         [0024]    Each member preferably comprises a pad, preferably made out of a soft material, as e.g. silicone, extending along the convex side of the curved section and the blade part. 
         [0025]    This pad advantageously comprises a haemostatic material. 
         [0026]    Reference to the remaining portions of the specification, including the drawings and claims, will realize other features and advantages of the present invention. Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with respect to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    These and further aspects of the invention will be explained in greater detail by way of example and with reference to the accompanying drawings in which: 
           [0028]      FIG. 1  is a view in perspective of a rib retractor according to the invention in working position; 
           [0029]      FIG. 2   a  is a sketch cross-section view along plane II-II of the rib retractor of  FIG. 1  in working position or shape; 
           [0030]      FIG. 2   b  is a sketch cross-section view of the rib retractor of  FIG. 2   a  in inserting position or shape; 
           [0031]      FIGS. 3 to 7  form a series of views in perspective of various stages in the use of a rib retractor of the invention; 
           [0032]      FIG. 3  is a view in perspective of the not yet assembled retractor; 
           [0033]      FIGS. 8 and 9  are sketch views in perspective of the jaws of the rib retractor in working position between two ribs; 
           [0034]      FIGS. 10 and 11  are sketch views in perspective of the jaws of a retractor according to the invention further comprising a stretching device; 
           [0035]      FIG. 12  is a view in perspective of the jaws of a retractor according to the invention further comprising another embodiment of stretching device; 
           [0036]      FIG. 13  is a cross-section view along plane II-II of another embodiment the rib retractor of  FIG. 1  in an intermediary position; 
           [0037]      FIG. 14  is a cross-section view along plane II-II of the rib retractor of  FIG. 1  in an intermediary position further comprising a soft pad. 
       
    
    
       [0038]    The figures are not drawn to scale. Generally, identical components are denoted by the same reference numerals in the figures. 
       DETAILED DESCRIPTION 
       [0039]    As can be seen from  FIGS. 1 ,  2   a  and  2   b , the rib retractor of the invention  1  is formed of a pair of members  2 ,  4 , each member having substantially, in transversal cross-section, a L-shape, the poles of the L extending parallel to each other when the retractor  1  is in working position ( FIGS. 1 and 2   a ). 
         [0040]    The upper or proximal parts of the poles of the L constitute the handles  6  of the rib retractor  1 . The lower or distal section of the poles, together with the base of the L, constitute the head section or the “jaws”  8  of the retractor  1 , as this retractor can be considered as a kind of pliers. Mutually engaging gearings  9  extending along both sides of the jaws  8  form pivoting connections. By acting on the handles  6 , the operator can force the members  2 ,  4  to pivot around the pivoting axes determined by the two pivoting connections, bringing the jaws  8  of the head section from an insertion to a working shape or position and reversely. 
         [0041]    One notes that when the retractor is in its insertion position ( FIG. 2   b ), the bases of the L-shaped members, which have the form of substantially flat blades  16  lean close to each other, so that they can be easily inserted between the ribs  14  of a ribcage. 
         [0042]    As apparent from  FIGS. 1 to 2   b , the pole part of the L forming each member  2 ,  4  is curved, the cave sides of the curves being directed towards each other. 
         [0043]    The use of the retractor  1  will become more obvious when looking at the series of  FIGS. 3 to 7 . 
         [0044]    In the embodiment displayed at  FIG. 3 , the mutually engaging gearings  32  are detachable from each other. Accordingly, the two members  2 ,  4  may be assembled at the very moment when the retractor  1  is put in service, meaning that it can be stocked unassembled in a very small sterile packaging. 
         [0045]    The two members  2 ,  4  having been put together, the retractor  1  is inserted, in its inserting shape, between two ribs  14 , through a relatively small hole cut between the required ribs of the patient. As represented in  FIG. 2   b , the blades  16  extending at the distal side of the retractor are at this stage close to each other and can thus be inserted easily between the edges of the incision. 
         [0046]    As shown at  FIG. 5 , the surgeon then applies a closing force on the handles  6 . This causes first the blades  16  to move around the ribs  14 , ensuring a good fastening of the retractor, but also the curved section  18  of the jaws to exert a cam effect on the ribs  14 , forcing them apart. 
         [0047]    The rib retractor having reached its working shape, the side parts of each curved section  18  of one jaw press against the corresponding side part of the other curved section  18 . They thus form together a steady ring which will delimitate the operating field. 
         [0048]    Each curved section  18  is provided at both lateral sides with sheaths  20 . As represented at  FIG. 6  the corresponding sheaths  20  of each curved section  18  lie at this moment (i.e. when the rib retractor is in working shape) parallel to each other. 
         [0049]    To reinforce the stability of this ring, U-form securing bridges  22  are then inserted into the adjoining sheaths  20 . 
         [0050]    The curved sections  18  forming now a mechanically continuous ring, the handles  6 , fastened to the jaws by known mortice and tenon joint means  21 , can be removed (see  FIG. 7 ). 
         [0051]    It will be noted that the slight curvature of the handles  6  not only allow them to match the curvature of the curved section  18  of the jaws, but also contributes to ensures their mechanical strength. An advantage of the present retractor  1  over prior art devices is that the surgeon can estimate, from the effort he has to exert on the handles  6 , the stress the ribs  14  undergo when pulled apart. 
         [0052]      FIGS. 8 and 9  are artist&#39;s views of the fastened jaws seen from various points of view. The securing bridges  22  comprise support means  24  for securing possible other medical devices as catheters, sucking tubes, suturing wires (the support means acting then as suture organizers), an apparatus as described in WO 2006/000514 and so on. 
         [0053]      FIGS. 10 and 11  display an advantageous additional feature  25  that can be used with the retractor  1  of the invention: if the surgeon is of opinion that the ribs  14  should be moved further apart, he can remove one of the securing bridges  22  and replace it by bolts  26  provided with an adequate inserting pin  28 , allowing them to be fastened to the sheaths  20  on one side of the jaws  18 . These bolts are movable relative to each other along a threaded shaft  30 , as represented, or along a (not represented) ratchet. Rotating the shaft  30  provokes a pulling apart on one side of the jaws  18 , the other side of the jaws rotating around the pins of the remaining securing bridge  22 . If needed, both securing bridges  22  can be replaced by such pulling-apart features  25 . Those features, contrary to other parts of the retractor, are advantageously made out of metal, while other parts of the retractor are preferably made out of disposable materials as polymers, for sake of sterility. The rib retractor according to the invention can also be provided with a series of bridges  22  of increasing lengths. If, for some reason, the surgeon wants to widen the operating field, he can remove one of the initial bridges  22  and exert a pulling (using a lever or specially designed forceps  32 ), as represented at  FIG. 12 , between the jaws  18 , which can then be maintained apart by a longer (not represented) bridge  22 . 
         [0054]      FIG. 13  displays another embodiment of the retractor wherein the mutually engaging gearings  9  extending along both sides of the curved sections  18  are replaced by ball-and socket joint means. Two parts  10  protruding between the jaws  8  on either sides of each curved section  18  form a pivoting connection  12 . 
         [0055]    As can be seen throughout the figures, the free ends of the blade parts are provided with fastening means  34 , allowing the fastening thereon of pads of soft materials  33  (as shown at  FIG. 14 ), which spread the stress exerted on the ribs  14  and the surrounding tissues, minimizing i.a. the risk of bruising the ribs  14 . A layer of haemostatic material  38  preventing blood to pour out into the operating field during the operation can also be provided. 
         [0056]    As particularly apparent from  FIG. 14 , the curved part  18  of the jaws  8  has a U-shaped cross-section. Accordingly, when the rib retractor is in working position, the upper (proximal) part of the curved section  18 , forming a lip  36 , rests on the outer side of the ribs  14 , ensuring a better stability of the ring. 
         [0057]    It will be appreciated by persons skilled in the art that the present invention is not limited by what has been particularly shown and described hereinabove. The invention resides in each and every novel characteristic feature and each and every combination of characteristic features. Reference numerals in the claims do not limit their protective scope. Use of the verb “to comprise” and its conjugations does not exclude the presence of elements other than those stated. Use of the article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. 
         [0058]    While the invention has been described by way of example and in terms of the specific embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements as would be apparent to those skilled in the art. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.