Abstract:
An surgical instrument for use during procedures to harvest saphenous veins simultaneously retracts tissue and exposes sections of the vein. Removable spacer limbs are selectively attached to the instrument to aid in retracting tissue and to make the instrument self-retaining.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to surgical instruments and more particularly to a surgical retractor well suited to harvesting saphenous veins for use in coronary bypass operations. 
     BACKGROUND OF THE INVENTION 
     Harvesting segments of the saphenous vein from the leg is a surgical procedure associated with coronary artery surgery. In general, segments of the patient&#39;s saphenous vein are removed, divided and repositioned in the coronary arterial system to improve coronary blood flow. 
     Early harvesting techniques involved conventional surgical cut down and open dissection of the leg to harvest the vein. In general less invasive procedures are preferred and several surgical devices have been developed to facilitate this procedure. See for example the “Mini Harvest” system manufactured by U.S. Surgical Corp. and the “VasoView” system manufactured by Origin as well as U.S. Pat. No. 5,667,480 to Knight et al. In general these systems are relatively complex and cumbersome in use although they are preferred over open dissection. 
     SUMMARY OF THE INVENTION 
     In contrast to the prior art, the surgical retractor of the present invention is an easily manipulated illuminated device for insertion into the surgical wound to illuminate the surgical field. In use the device is manipulated by the physician and can be used to expose sections of the vein and it may be used to facilitate blunt dissection along the length of the vein. In operation the device can be used to simultaneously retract tissue and illuminate the surgical field at the same location. The illustrated embodiments of the device include a light source located near the distal tip of the retractor with an integral or remote power source of the light source. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Throughout the several views of the drawing identical reference numerals refer to equivalent structural elements, wherein: 
     FIG. 1 is an illustrative view of an embodiment of a surgical instrument; 
     FIG. 2 is an illustrative view of the embodiment of a surgical instrument shown in FIG. 1; 
     FIG. 3 is a perspective view, generally from the side, of another embodiment of a surgical instrument; 
     FIG.  4 . is a perspective view, generally from the rear, of the surgical instrument illustrated in FIG. 3; 
     FIGS. 5 a  and  5   b  are perspective views, generally from the side, of the instrument shown in FIG. 3, with separable portions illustrated separately; 
     FIG. 6 is a perspective view, generally from the side, of an alternate embodiment of a surgical instrument; 
     FIG. 7 is an enlarged schematic side view of a portion of a surgical instrument according to the present invention; 
     FIG. 8 is an enlarged schematic side view of a portion of a surgical instrument according to the present invention; 
     FIG. 9 is a perspective view, generally from the front, of a spacer support assembly for use in conjunction with the surgical instrument illustrated in FIG. 3; 
     FIG. 10 is a perspective view, generally from the side, of the surgical instrument of FIG. 3 in use, with hidden portions under tissue indicated by dotted lines; 
     FIG. 11 is a perspective view, generally from the side, of a surgical instrument of FIG. 3 in use, with hidden portions under tissue indicated by dotted lines. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 shows a side view of an embodiment of the surgical instrument  10 . A handle  12  is provided to receive the hand of the physician. A power source is provided and is illustrated by a pair of batteries illustrated in the figure by battery  14  and battery  16  which may be located inside of the handle  12 . In this embodiment the proximal end of the handle  12  includes a switch assembly  18  which can be used to turn on the light source  22  or lamp. 
     A retractor blade  20  is anchored at the distal end of the handle  12 . In general this retractor blade lies in a single plane and bends “away” from the handle  12 . Preferably, the blade attaches to the handle with a malleable construction, such that angle between the blade and the handle is adjustable to some degree by the user. Near the distal tip of the retractor blade  20  is a lamp  22  or other source of illumination. In the embodiment shown in the drawing a single incandescent bulb is shown mounted on a web  24  spanning the distance between the first limb  26  and the second limb  28  of the retractor blade  20 . In general it is best to mount the bulb such that the cone of illumination  30  is directed away from the handle  12 . In use this illumination source directs light into the surgical field surrounding and defined by the distal tip of the retractor blade. 
     FIG. 2 shows an end view of the surgical instrument  10 . In this view the two members  26  and  28  can be seen forming conductors for the light source  22 . The web  24  can be seen spanning the distance between the two members. In general the web  24  is formed from a plastic material and the web adds mechanical strength to support the two members  26  and  28 . The circuit to the power source is completed by suitable wiring  32  which couples the member  26  conductor to a battery  16 . A complimentary wire  34  couples member  28  to the switch assembly  18 . The user with line of sight along line  35  from eye position  37  observes the surgical field between the two limbs  26  and limb  28 . The line  35  forms an axis which lies in the plane generally defined by the two limb members  26  and  28 . 
     FIGS. 3-6 illustrate embodiments of a surgical instrument that include a support or spacer arrangement which aids in holding open a tunnel through the tissue surrounding the saphenous vein for easily viewing the dissection area without having to hold and pull up on the surgical instrument at all times. In the embodiment of the surgical instrument  100  illustrated in FIGS. 3-5, the spacer arrangement is indicated at reference number  110 ; in the embodiment of the surgical instrument  200  illustrated in FIG. 6, the spacer arrangement is indicated at reference number  210 . 
     As illustrated in FIG. 3, the spacer arrangement  110  includes two spacer limbs  115  and  116 . The spacer limbs  115  and  116  each extend generally parallel to the plane defined by limbs  120  and  121 . Spacer limbs  115  and  116  are spaced apart from each other and are obliquely oriented in a preferred embodiment such that the terminating distal tips  125  and  126  are closer together than the opposite end portions  130 ,  131  of the limbs  115  and  116 . The distal tips  125  and  126  may be connected or bridged or spanned to add mechanical strength. Alternatively, the orientation of disjoined spacer limbs to one another can be adjustable such that the spacer limbs can selectively be spread apart in a semi-V formation as illustrated in FIG.  11 . 
     Preferably the distance  133  between the spacer limbs  115 ,  116  and the plane defined by limbs  120 ,  121  is variable between almost zero inches and about 2.5 inches. A relatively small distance will be used in operation when the device in introduced into an incision. The spacer limbs will then be extended to a distance of between about 1.0 inch and 2.5 inches to hold open a tunnel to facility the viewing of the surgical field. Preferably the spacer limbs  115 ,  116  can be locked or secured into a desired position relative to the limbs  120 ,  121  such that the instrument  100  supports a tunnel about the saphenous vein. This allows a clear view of and convenient access to the surgical field and even allows the user to let go of the instrument while the instrument maintains an open tunnel. 
     The spacer limbs  115 ,  116  illustrated in FIGS. 3-11 are generally circular in cross-section, though other shapes are contemplated. For example, the spacer limbs  115 ,  116  may be flattened with a rectangular or elliptical cross-section; alternatively, the spacer limbs  115 ,  116  may be generally circular in cross-section, but may include portions having flattened rectangular or elliptical cross-sections. The surfaces of the blade limbs  120 ,  121  and spacer limbs  115 ,  116  that engage tissue may be smooth or rough. Rough or ridged surfaces will provide increased frictional engagement between the tissue and the instrument. 
     A preferred embodiment includes two spacer limbs  115 ,  116 ; alternate embodiments are operable with one spacer limb or with more than two spacer limbs. 
     The spacer limbs  115 ,  116  can be coupled to the instrument in a number of ways. Preferably, as illustrated in FIG. 3, the spacer limbs  115 ,  116  are slidably coupled to the limbs  120  and  121  such that the distance between spacer limbs  115 ,  116  and the plane defined by limbs  120  and  121  is selectively variable. More specifically, as illustrated in the embodiment of FIGS. 3 and 4, the spacer limbs  115  and  116  are slidably coupled to the handle  135 . Each spacer limb  115 ,  116  is integrally formed with an elongate member  140 ,  141 , respectively, oriented generally perpendicular to the spacer limb  115 ,  116 . This elongate member  140 ,  141  resides in a tube  150 ,  151  coupled to the handle  135 . Tubes  150 ,  151  terminate in proximal ends  153 ,  154  and at distal ends  156 ,  157 . Preferably, the elongate members  140 ,  141  are sized to slide in a longitudinal direction within the respective tube  150 ,  151 . Flanges  160 ,  161  are integrally coupled to the proximal ends of the elongate member  140 ,  141  and are disposed generally perpendicular to the elongate member. The flanges  160 ,  161  limit the movement of the elongate member in the distal direction by abutting the proximal end  153 ,  154  of the tube  150 ,  151 . The flanges further function as handles for the user to manipulate to adjust the longitudinal position of the spacer limbs  115 ,  116 . In a preferred embodiment, the elongate members  140 ,  141  are independently moveable, such that spacer limbs  115 ,  116  can accordingly be separately or independently adjusted. In an alternate embodiment, member  140 ,  141  move in unison. The device can be constructed to allow the extension members to slide continuously through tubes  150 ,  151 . Alternatively, the device can be constructed, for example with click stops, to provide one or more predefined preferred positions for the extension members to accommodate one or more predefined preferred distances between the spacer limbs and the plane defined by limbs  120  and  121 . 
     Preferably, the spacer limbs  115 ,  116  are coupled to the blade limbs  120 ,  121  such that the angle defined between the spacer limbs and the blade limbs is adjustable, such as through malleability of the spacer limbs  115 ,  116 , the extension members  140 ,  141  and/or the junction therebetween. 
     Additional arrangements for attaching the spacer limbs to the instrument are contemplated. For example, tubes  150 ,  151  can be fixed directly to the handle  135 , such as by welding or gluing. Preferably, the tubes  150 ,  151 , and therefore the limbs  115 ,  116 , are removably coupled to the surgical instrument  100 . As illustrated in FIGS. 5 a  and  5   b , the spacer limbs  115 ,  116  are part of a spacer support assembly  170  which releasably attaches to the surgical instrument  100 . In the embodiment illustrated in FIGS. 3-5, the spacer support assembly  170  includes a jacket  175  which attaches to the handle  135  by wrapping around it and clamping thereto. In one embodiment, illustrated in FIG. 9, the jacket  175  includes a living hinge  177  that opens for the jacket to receive the handle  135 . Alternatively, the jacket  175  is made of a material, such as spring steel, that is resilient enough to allow the jacket to spread open to receive the handle, and then spring back to grip the handle  135 . Other arrangements for attaching the jacket and/or the spacer limbs to the instrument  100  are contemplated. For example, the handle  135  can include notches, clips or the like to mate with corresponding structure on the jacket  175  or on tubes  150 ,  151 . 
     FIG. 6 illustrates another embodiment of a surgical instrument  200  according to the present invention. This embodiment is similar to the embodiments illustrated in FIGS. 1-5. The spacer arrangement  210  includes support feet or skis  211 ,  212  that extend from elongate extension members  240 ,  241  in a direction generally opposite of that in which the spacer limbs  215 ,  216  extend. The feet  211 ,  212  add to the stability of the device and aid in supporting the instrument when it is in position inside an incision. 
     Preferably, the web and light source arrangement is constructed to project light predominantly in the downward and forward directions. In this manner, the light that is projected onto the surgical area is maximized and the light projected onto surrounding areas is minimized. Further, by directing light forwardly, the user is not blinded by light shining rearwardly toward the use. The directional terms downwardly and forwardly as used herein relate to the orientation of the device as it is typically used in practice, though it should be understood that such terms are not intended to be limiting. More specifically, as illustrated in FIG. 7, the instrument has a reflective layer  310  adjacent a light source  315 , such as a “grain of wheat” light, which is adjacent a window  317  through which the light shines. The reflective layer inhibits light from passing upwardly. In addition, a shaded area partially obstructs the rearward projection of light. Alternatively, as illustrated in FIG. 8, the web and light source arrangement is constructed with a light-refracting lens  350 , such as a Fresnel lens, adjacent a light source  351 . 
     In use, a surgeon performs an incision and isolates a saphenous vein with a Metzenbaum scissors, loop vein with elastic vessel loop. The surgeon then dissects the vein through proximal and distal incisions as far as visually possible using a Green Goiter. The surgeon then develops a tunnel using gentle digital dissection. Next, the lighted surgical instrument according to the present invention is inserted into the incision. In one preferred method, illustrated in FIG. 10, the blade limbs  120 ,  121  and the spacer limbs  115 ,  116  are all inserted into the incision or under the skin. In an alternate method, illustrated in FIG. 11, the blade limbs  120 ,  121  are inserted under the skin, while the spacer limbs  115 ,  116  engage the outside of the skin adjacent the incision. In this alternate method, the spacer limbs  115 ,  116  are preferably spread apart from one another such that they are not generally parallel, but rather form a truncated “V”. 
     With the instrument inserted, the surgeon continues dissection allowing the surgical instrument according to the present invention to simultaneously illuminate and provide tunnel wall separation and retraction while using vessel loops for mobilization, medially and laterally. The surgeon locates side and perforating branches by slightly retracting the main saphenous vein. 
     In greater detail, the surgeon chooses a location for an initial incision to gain direct access to saphenous vein. After an incision is made and a vein located, a small spring retractor is used for skin retraction of the wound. 
     A Metzenbaum scissors (or similar tool) is used to dissect and isolate the vein from surrounding tissues. An elastic vessel band is then used to loop the vein enabling the surgeon to retract the vessel either laterally or medially by weighting the loop ends with a single small clamp. This, then, frees up both hands for continued dissection. 
     The surgeon then isolates the vein from surrounding tissues both proximally and distally within the incision as far as is possible without the aid of additional tissue retraction devices. The surgeon then inserts a “Green Goiter” retractor to facilitate the continued dissection in both directions within the wound. This tool provides good visualization for dissection as the tunnel is created but before additional light becomes necessary. 
     The surgeon then inserts a finger into the incision and begins to gently create a digitally guided tunnel adjacent to the course of the saphenous vein. The surgeon performs this maneuver in both directions from this single incision. 
     Next, the surgical instrument  100  according to the present invention is inserted into the digitally-created tunnel. It is held to obtain optimal lighting and for optimal retraction for further vein dissection. This process is repeated in the opposite direction. 
     The surgeon then uses curved Metzenbaum scissors or similar tool to isolate vessel side branches while using vessel loop to mobilize the vein in various directions as necessary. Once dissection has reached the point where vessel loops become less helpful and two hands would better facilitate dissection, spacer support arrangement  170  can be attached to the retractor and the spacer limbs  115 ,  116  deployed. This allows the retractor to stand alone using its own retraction technique to hold it securely in place within the tunnel. 
     Vein side branches can be double clipped with a clip applier while smaller ones can be separated by a bipolar cautery device. Branches that cannot easily be reached can wait until the conduit vessel is ready for removal from the tunnel. 
     Using a surgical instrument  100  according to the present invention, the surgeon identifiies the course of the saphenous vein under direct visualization to facilitate the positioning of the second incision. Once the second incision is made, the vein is retracted from the initial incision to help locate its exact position within the new incision. The surgeon then performs the dissection maneuvers described above with respect to the first incision, using a finger to carefully connect the vein tunnel in the second incision to the vein tunnel of the first incision. 
     After two or more incisions have been made to isolate the appropriate length of vein and both proximal and distal ends of the vein are severed, the double-clipped branches can now be cut between the clips or the unclipped branches can be separated with cautery scissors. The vein conduit is gently pulled from the tunnel with care being taken not to dislodge any clips in the process. With the conduit on the surgical field, preparation of the vein can be completed by clipping all side branches where necessary and checking carefully for any fluid leakage along the length of the vessel. 
     Although a preferred embodiment of the instrument has been shown there are a number of variations that should considered within the scope of the claims. For, example the members  26  and  28  are shown as solid wire forms but alternate cross section forms are practical including square and rectangular shapes. Tubular shape may be used as well. Although the inclusion of the power source in the handle is preferred for disposable versions of the device it should be clear that a remote power supply could be coupled to the handle via connector  36  to power the light source  22  from a remote supply (not shown). In a similar fashion the switch may take any conventional form or may be integrated into a remote power pack. The “bend” of the retractor blade  20  is acute with respect to the handle as indicated by angle A but other angular relationships are operable as well. For example the handle could be a reusable element with removable and disposable retractor blades temporally attached or coupled to the handle. The use of the members  26  and  28  as the conductors is preferred but separate wires may be used to deliver power to the light source  22 .