FIELD OF THE INVENTIONThis invention relates to surgical devices and methods for dissecting around elongated tissue structures. In particular, this invention relates to devices and methods for dissecting around a blood vessel such as a saphenous vein during an endoscopic vessel harvesting procedure.[0001]
BACKGROUND OF THE INVENTIONEndoscopic vein harvesting (EVH), particularly of the greater saphenous vein in the leg, is a surgical procedure for obtaining a graft vessel for a coronary artery bypass graft (CABG) procedure. A physician's assistant (PA) typically performs the EVH on one or both legs of the patient while a cardiac surgeon operates on the patient's chest in preparation for the grafts. Performing the EVH in a timely manner is important so that the PA can present the prepped vessel to the surgeon by the time the surgeon is ready to attach the graft vessel to the heart. The EVH procedure learning curve and additional time required to harvest a blood vessel using minimally invasive techniques continue to be issues for the rapid adoption of the procedure. The present invention improves the ease of use and decreases the time required to harvest a vessel. Specifically, this invention reduces the number of instrument exchanges through the surgical incision in the patient.[0002]
Several investigators have proposed devices and methods for performing EVH, as disclosed in the patents cited. For example, U.S. Pat. No. 5,928,138 (“Method and Devices for Endoscopic Vessel Harvesting”, assigned to Ethicon Endo-Surgery, Inc., and issued on Jul. 27, 1999) discloses an optical dissector having a concave working head. A commercial version of this optical dissector is called the ClearGlide subcutaneous retractor and is available from Ethicon, Inc., Somerville, N.J. The ClearGlide is currently one of the main products available today for performing EVH, and provides good access and visibility to the surgical site along the greater saphenous vein.[0003]
The PA normally uses the ClearGlide with other endoscopic, surgical dissection instruments in order to isolate the vessel from surrounding tissues. The PA introduces these instruments through a channel provided in the handle and shaft of the ClearGlide in order to operate on tissues within a working space created by a concave working head.[0004]
Known methods and devices for performing vessel dissection are discussed in detail in U.S. Pat. Nos. 5,667,480 issued Sep. 16, 1997 and 5,722,934 issued Mar. 3, 1998, both issued to Knight, et al, both of which are incorporated herein by their reference.[0005]
Of the known devices and methods for dissection of tissues there remains one constant problem. The problem is that to perform the dissection, extra tools must be inserted along the guide rails of the device through the original incision. Often times this means that to perform a single dissection of a vessel multiple tools must be inserted in succession into the body. Additionally, the harvesting device remains in the body throughout the procedure.[0006]
This requirement of inserting the tools in succession and exchanging one tool for another to perform each step of the operation requires extra time, this in turn can be a drain on the individual surgeons resources. Further, because of this increased amount of time, which the surgeon requires to perform the operation, the stress on the patient is increased. Minimization of patient stress is naturally a concern during any surgical procedure. Therefore, the elimination of some or all of the time extending tool exchanges would greatly benefit not only the patient but the surgeon as well.[0007]
What is needed, therefore, is a surgical instrument having a concave working head for creating a working space near the vessel to be harvested, and that has at least one dissection element connected to the concave working head. An operator may use the dissection element for dissecting around all sides of the vessel so that it is less necessary to use other dissection instruments. The operator may also use the dissecting element for supporting a tissue structure such as a side branch while it is operated on by another surgical instrument, such as a surgical scissors, ligation instrument, or the like.[0008]
SUMMARY OF THE INVENTIONThe present invention is directed to solving the shortcomings of known vessel retractors, by providing a superior vessel retractor, promoting efficient dissection of vessels, and limiting the stress on patients. The objects of the present invention are the minimization of the tool exchanges, increased efficiency of operation, minimization of patient stress, and increased ease of the overall harvest operation. Further, the present invention pertains to a vessel retractor having a dissecting element. The surgical instrument comprises a spoon retractor having a proximal end and a distal end, said spoon retractor defining a working space in the tissue of a patient, a dissecting element proximate to said spoon retractor for dissecting tissue from a vessel, and means for manipulating said spoon retractor near the vessel. The means for introducing and manipulating the spoon retractor near the vessel comprises, a shaft having a distal end and a proximal end, the distal end of the shaft connected to the proximal end of the spoon retractor, the shaft having a lumen in communication with the working space for insertion of an endoscope there through and a handle connected to a proximal end of the shaft for manipulation of the spoon retractor connected thereto.[0009]
The dissecting element may be rigidly fastened to the spoon retractor. In such a configuration the dissecting element comprises a wireform, the wireform comprises a left side rail and a right side rail rigidly connected to the spoon retractor at a proximal end of the wireform, said left and right side rails being connected to each other at a distal end of the wireform and dissecting tissue from the left and right surfaces of the vessel. Additionally the wireform may project upward in the direction of the spoon retractor, and form a U-shape at the distal end of the wireform to facilitate placement of the vessel between the left and right side rails.[0010]
The surgical instrument may comprise a control for controlling the dissecting element, when the dissecting element movably connects to the spoon retractor and moves relative to said spoon retractor upon actuation of the control, to facilitate dissection of tissue from the vessel. In such a configuration the dissecting element comprises a movable arm having an extended portion and a shank, the movable arm being rotatable about an axis defined by the shank.[0011]
In another configuration the dissection element may comprise a flexible arm slidably retained in said spoon retractor, and movable between an extended position and a retracted position. In such a configuration the distal end of the flexible arm defines at least one curved portion, the curved portion further defining an arm which extends to an outer edge of the flexible arm and facilitating the dissection of tissue from the vessel. The flexible arm is prevented from entering the workspace by guide rails.[0012]
Also provided is a method for dissecting a vessel comprising the steps of: providing a surgical instrument for dissecting a vessel in a patient; said surgical instrument comprising a spoon retractor having a proximal end and a distal end; said spoon retractor defining a working space in the tissue of the patient near the vessel to be dissected; a dissecting element proximate to said spoon retractor for dissecting tissue from a vessel; and a means for manipulating said spoon retractor near the vessel, making an incision in a patient; inserting said spoon retractor into the incision; creating a working space in the tissue of the patient near the vessel being dissected; and manipulating said dissecting element to further dissect tissue surrounding the vessel being dissected.[0013]
The method further comprises the step of providing a surgical instrument for dissecting a vessel comprising a wireform rigidly attached to the spoon retractor, the wireform comprising a left side rail and a right side rail rigidly connected to the spoon retractor at a proximal end of the wireform, said left and right sides being connected to each other at a distal end of the wireform.[0014]
Preferably the manipulating step comprises sliding the wireform along the vessel while the left and rights sides are laterally disposed on the left and right sides of the vessel respectively.[0015]
In a configuration where the dissecting element is movably connected to the spoon retractor, the manipulating step may comprise moving the dissecting element relative to said spoon retractor upon actuation of a control.[0016]
In a configuration where said dissecting element is a movable arm having an extended portion and a shank, the manipulation may comprise rotating the movable arm about an axis defined by the shank, wherein said manipulating step further comprises sliding the spoon retractor and attached the dissection element along the vessel, and rotating the movable arm about the vessel to dissect the vessel from the surrounding tissue.[0017]
The method for dissecting may also comprise using a dissecting element comprising a flexible arm slidably retained in said spoon retractor, and movable between an extended position and a retracted position. Wherein the distal end of the flexible arm defines at least one curved portion, the curved portion further defining an arm which extends to an outer edge of the flexible arm.[0018]
In such a configuration the manipulating step preferably comprises, extending the flexible arm from the retracted to the extended position, and sliding the spoon retractor and attached dissection element along the vessel, wherein the curved portion of the flexible arm is placed on at least one side of the vessel to dissect the vessel from the surrounding tissue.[0019]
BRIEF SUMMARY OF THE DRAWINGSFIG. 1 is a perspective view of a preferred implementation of a surgical instrument of the present invention, used for dissecting and harvesting a vein;[0020]
FIG. 2 is a front view of a spoon retractor of the surgical instrument of FIG. 1, the spoon retractor having a flexible arm as a dissecting element in an extended position;[0021]
FIG. 3 is a side sectional view of the spoon retractor shown in FIG. 2 taken along line[0022]3-3;
FIG. 4 is a sectional view of the spoon retractor shown in FIG. 3 taken along line[0023]4-4;
FIG. 5 is a side view of the spoon retractor shown in FIG. 3 in a retracted position;[0024]
FIG. 6 is a bottom view of the spoon retractor shown in FIG. 5 in the retracted position;[0025]
FIG. 7 is a front view of a first variation of the spoon retractor of the present invention with curved edges as a dissecting element;[0026]
FIG. 8 is a side view of the spoon retractor shown in FIG. 7;[0027]
FIG. 9 is a front view of a second variation of the spoon retractor of the present invention with fixed rails as a dissecting element;[0028]
FIG. 10 is a side view of the spoon retractor shown in FIG. 9;[0029]
FIG. 11 is a front view of a third variation of the spoon retractor of the present invention with a movable arm as a dissecting element in a retracted position;[0030]
FIG. 12 is a side view of the spoon retractor shown in FIG. 11;[0031]
FIG. 13 is a front view of the spoon retractor shown in FIG. 11 in an extended position; and[0032]
FIG. 14 is a side view of the spoon retractor shown in FIG. 13 in an extended position.[0033]
DETAILED DESCRIPTION OF THE INVENTIONA surgical instrument for endoscopic dissection of vessels for CABG surgery as known in the art generally comprises a concave working head, a shaft, and a handle. The instrument is typically fitted with an endoscope inserted through a handle and the shaft so that an operator may view into a working space created by concave working head.[0034]
In operation the surgeon introduces the concave working head and a portion of shaft through a surgical incision and manipulates surgical instrument alongside the saphenous vein in order to free the vein from surrounding tissues and to isolate side branches of the vein that must be ligated prior to removal of the vein from the patient's leg.[0035]
The concave working head may be made from a clear plastic so that the operator may visualize tissue structures adjacent to it as well as inside the working space. U.S. Pat. No. 5,928,138 also discloses how surgical instrument may be used with other surgical instruments for dissecting and harvesting a vein. The present invention reduces the time required to perform the EVH procedure (and subsequent trauma to tissue) due to fewer exchanges of these additional instruments into incision.[0036]
Referring now to FIG. 1, a surgical instrument is illustrated therein generally referred to by[0037]reference number2. The present invention includes at least one dissecting element (shown in FIGS.2-14), which is either movably connected or fixed to a concave working head, also referred to as aspoon retractor10. Thespoon retractor10 is useful for dissection of tissue such as is required for separating the saphenous vein from surrounding tissues during an EVH.Surgical instrument2 may be used with anendoscope18 in order to view inside the working space. In the descriptions that follow, several variations of thespoon retractor10 and dissecting elements are described. For the embodiments shown, thespoon retractor10 is preferably attached to anelongated shaft1 and ahandle3, similar to the surgical instrument of the prior art.
FIG. 2 is a front view and FIG. 3 is a side sectional view of a[0038]spoon retractor10 of the present invention.Spoon retractor10 is an improvement of concave working head of the prior art. In this implementation,spoon retractor10 is symmetrically shaped with aproximal end17 attached to the distal end of ashaft1.Spoon retractor10 tapers to a distal end19 so that anoperator4 may easily usespoon retractor10 to separate tissue layers and isolate avein6 from surrounding tissues.Spoon retractor10 is preferably made of a medical grade, injection moldable plastic such as polycarbonate and is optionally clear for endoscopic viewing of tissue both inside the working space and adjacent to spoonretractor10. In the implementation of FIGS. 2 and 3,spoon retractor10 includes a retractable,flexible arm12. Anupper layer14 and alower layer16 ofspoon retractor10 define a channel that extends partially between distal end19 andproximal end17, and slidably retainsflexible arm12. Anoperator4 may positionflexible arm12 at an extended position such as shown in FIGS. 2 and 3, at a retracted position, as shown in FIGS. 4 and 5, or at any position between the extended and retracted positions. A control (not shown) for movingflexible arm12 is preferably located on a portion of thesurgical instrument2 that remains external to the patient during the procedure, such as on theproximal end50 ofshaft1 or onhandle3, as may be easily envisioned by those skilled in the art.
In the retracted position, the[0039]flexible arm12 lies above the level of theendoscope18, and portions which are located outside of thespoon retractor10 may lie on theshaft1.Flexible arm12 may be made of a medical grade, injection moldable plastic such as high-density polyethylene. A distal end offlexible arm12 comprises two opposing curved portions11 for a traumatically sliding along the sides of an elongate tissue structure such as avein6 in order to free thevein6 from surrounding tissues. Curved portions11 define anarm13 that extends distally to anouter edge15 to assist in separating thevein6 from the connecting tissues.
FIG. 6 shows a bottom view of[0040]spoon retractor10 and corresponds with FIGS. 4 and 5 for whenflexible arm12 is in the retracted position. Lower layer16 (see FIG. 3) comprises twoguide rails22 to supportflexible arm12.Guide rails22 connect to an inside surface ofspoon retractor10. The guide rails22 also serve to insure that theflexible arm12 does not restrict the field of view of theendoscope18.
FIGS. 7 and 8 are a front view and a side view of a first variation of a[0041]spoon retractor10, respectively, with a leftcurved edge30 and an opposing rightcurved edge31 extending from abottom edge29 on each side ofspoon retractor10. In this implementation, a left middle section (not shown) and a rightmiddle section34 blends with the curvation on each side ofspoon retractor10. As can be seen in FIG. 7, leftcurved edge30, rightcurved edge31 andspoon retractor10 approximately surround the longitudinal axis ofspoon retractor10, thus allowing an operator to placespoon retractor10 near a vessel with leftcurved edge30 and rightcurved edge31 on opposing sides of the vessel. Theoperator4 may then slidespoon retractor10 back and forth along the vessel to free the vessel from surrounding tissue.
FIGS. 9 and 10 show a second variation of the[0042]spoon retractor10 of the present invention. FIG. 9 is a front view and FIG. 10 is a side view, showing awireform dissecting element37 comprising aleft side rail38 and aright side rail39 fixed tospoon retractor10.Wireform dissecting element37 preferably has a curveddistal end36 joiningleft side rail38 andright side rail39.Wireform dissecting element37 further comprises a pair of proximal ends44, which are fixedly connected tospoon retractor10.Cavity48 ofspoon retractor10 retains and supports curveddistal end36.Wireform dissecting element37 is made from a medical grade material such as stainless steel wire having a diameter approximately in the range of one to two millimeters. Theoperator4 may position leftside rail38 andright side rail39 and on either side of a vessel and movespoon retractor10 slowly forward and back toseparate vein6 from the connecting tissue layers.
FIGS.[0043]11-14 show a third variation of thespoon retractor10 of the present invention. FIGS. 11 and 12 show front and side views, respectively, ofspoon retractor10, and include amovable arm50 shown in a first position. Anextended portion46 at a proximal end42 of thespoon retractor10 rotatably retains ashank54 ofmovable arm50. Anoperator4 movesmovable arm50 between the retracted first position and a second position (FIGS. 11 and 13, respectively) by actuating a rotation control (not shown) preferably located on the proximal end ofshaft1 or on handle3 (see FIG. 1). Actuation of a distal element of a surgical element by a control rod is well known in the art.
[0044]Movable arm50 includes atip52 for dissecting tissues.Shank54 preferably lies directly belowendoscope18.Movable arm50 is preferably made from a stainless steel wire having a diameter approximately in the range of one to two millimeters.Movable arm50 may rotate in either direction about the axis defined by the shank and may also rotate a full 360 degrees.
The operation of the[0045]surgical instrument2 of the present invention will now be discussed with reference to the figures. Thesurgical instrument2 of the present invention has a particular ability in dissecting vessels from tissue in a patient however, such a use is given by way of example only and does not limit the scope or spirit of the present invention.
Once a device comprising at least one of the dissection elements discussed above is provided, the surgeon determines the location of the vessel to be dissected, and makes an incision in the patient. The spoon retractor is inserted into the incision and blunt dissection of the tissue surrounding the[0046]vessel6 is performed. For extraction purposes, it is preferable to dissect as much tissue from the vessel as possible. The initial insertion of thespoon retractor10 creates a workingspace7 in the tissue of the patient near thevessel6 being dissected. This working space provides a location where the operator may utilize the various dissection elements, discussed above to dissection the vessel from the surrounding tissue. Finally the dissection elements need to be manipulated by the user to further dissect tissue surrounding thevessel6 being dissected.
The dissection of the[0047]vessel6 is accomplished by moving thespoon retractor10 along the vessel and separating the tissue from the vessel. To assist in the dissection there are various forms of dissection elements which can be provided, as discussed above. Each of the various dissection elements can be incorporated into the method described here with some variation of the manipulation step.
One of the dissection elements which may be provided is shown in FIGS. 7 and 8. The dissection element comprises the[0048]spoon retractor10 havingcurved edges30,31 extending from the bottom edge on each side of the spoon retractor. The dissection element is used by orienting thevessel6 between the twocurved edges31. Once the vessel is so oriented thespoon retractor10 is moved along thevessel6. This movement causes thecurved edges30,31 to dissect the vessel from the tissue located on either side.
Another dissection element provided comprises a rigidly attached[0049]wireform37 having left and right side rails38,39, and these rails are connected at the distal end of thewireform37. Such adissection element37 is used by orienting theleft side rail38, on a first side of thevessel6, and theright side rail39 on a second side of thevessel6. The vessel is captured by the wireform by operation of the U-Shape connection point of the dissection element. After thevessel6 is captured, thespoon retractor10 andwireform37 are slid along the length of the vessel. The left side rail dissecting on the first side of the vessel and the right side rail dissecting the right side of the vessel. The U-shaped connection assists in the dissection of tissue on the top surface of the vessel.
Yet another dissection provided is one having a[0050]movable arm50 having an extended portion and ashank44 as shown in FIGS.11-14. The dissecting element is movably connected to thespoon retractor10, and the manipulation comprises rotating themovable arm50 about an axis defined by theshank44. Sliding thespoon retractor10 and attachedmovable arm50 along the vessel, and simultaneously rotating themovable arm50 about the vessel tissue, dissects on all sides of the vessel from the surrounding tissue.
Additionally, when the[0051]movable arm50 is in the position shown in FIG. 14, the dissection element can slidingly engage the tissue along the axis defined by the shank to dissect it from the vessel. Themovable arm50 can be forced along one side of thevessel6 while thespoon retractor10 is moved along another surface of thevessel6. Upon projecting the spoon retractor a certain distance, the movable arm can be rotated to dissect tissue from the vessel by the circumferential movement of the movable arm around thevessel6.
Still another dissection element provided is one having a[0052]flexible arm12 slidably retained in said spoon retractor, and movable between an extended position and a retracted position, as shown in FIGS.2-8. The distal end of theflexible arm12 defines at least one curved portion11. The curved portion11 further defining anarm13 which extends to an outer edge of theflexible arm12. This dissection element is manipulated by extending the flexible arm from the retracted to the extended position, and sliding thespoon retractor10 and attachedflexible arm12 along thevessel6, at the same time the curved portion11 of theflexible arm12 is placed on at least one side of the vessel6to dissect thevessel6 from the surrounding tissue. Typically, theflexible arm12 has two curved portions11 and will be used to dissect the tissue from one side of thevessel6 and then a second side of thevessel6. During the dissection the curved portion11 slides along the surface of thevessel6. Thearm13 facilitates the dissection on the underside of thevessel6.
Those skilled in the art will appreciate that the methods of the present invention do not require the insertion multiple dissection tools to perform procedure. Nor do they require multiple tool exchanges. Accordingly, the procedure as a whole is far easier, and efficient that those previously known. As a result the stress on the patient is reduced.[0053]
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modification are intended to be included within the scope of this invention as defined in the following claims.[0054]