Abstract:
A trocar system is described. The trocar system allows for penetration into the patient&#39;s laparoscopic cavity while also allowing visualization once an imaging device (e.g., a laparoscope) is inserted into the hollow shaft of the trocar. Attached to a distal end of the trocar shaft is a tip portion, which may be comprised of a transparent material, and which allows for general visualization upon penetration into the patient&#39;s laparoscopic cavity. The tip may include a conical shape with at least one blade (e.g., preferably at least two blades) protruding longitudinally along a peripheral surface thereof. The blades may be comprised of a metallic material, e.g., preferably similar to the trocar shaft material, and may be securely attached (e.g., preferably welded) to the trocar shaft. The transparent tip may be caged by the blades and the trocar&#39;s shaft and may also be glued to the blades and trocar shaft as well. The metallic blades provide numerous advantages, such as but not limited to, assisting in the penetration through the patient&#39;s abdominal wall, while at the same time securing the conical transparent tip portion to the trocar&#39;s shaft and thus reducing the risk of breakage and/or unintended detachment therefrom.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The instant application claims priority to U.S. Provisional Patent Application Ser. No. 61/354,842 filed Jun. 15, 2010, pending, the entire specification of which is expressly incorporated herein by reference. 
     
    
     FIELD OF INVENTION 
       [0002]    The present invention relates generally to trocar systems and more specifically to trocar systems with a transparent tip portion attached to a distal end of the trocar shaft, and methods for making the same. 
       BACKGROUND OF THE INVENTION 
       [0003]    Endoscopy, and especially laparoscopic endoscopy, has been a rapidly growing surgical practice in the past decades. Accessing the patient&#39;s laparoscopic cavity is typically done via holes, usually punctured with a sharp element referred to as a trocar. In order to penetrate the patient&#39;s laparoscopic cavity, the trocar is typically placed into a tubular element referred to as a cannula, such that the sharp end of the trocar is protruding from the cannula&#39;s distal end. The trocar end, when sharp, may puncture the abdominal wall. When a blunt trocar is used, an initial incision to the patient&#39;s skin may be required. 
         [0004]    In practice, the surgeon typically presses the cannula/trocar tandem against the patient&#39;s abdominal wall and carefully penetrates into the insufflated laparoscopic cavity, while devoting great care in avoiding injuries to any internal organs. Until transparent tip portions were introduced, the penetration procedure was executed in an essentially “blind” fashion, relying mostly on the surgeon&#39;s skills. However, the addition of a transparent tip portion to the distal portion of the shaft of the trocar, as well as the use of an illuminated scope device (e.g., placed behind the tip portion within the hollow shaft of the trocar) has greatly increased the safety level and added a level of visualization such that undesired penetration of any internal organs has been greatly reduced. However, conventional systems and methods for manufacturing trocars with transparent tip portions have been difficult, expensive and laborious, along with producing unsatisfactory results. 
         [0005]    Accordingly, there exists a need for new and improved trocar systems that include a transparent tip portion engaged to a distal portion of the trocar shaft, and methods for making the same. 
       SUMMARY OF THE INVENTION 
       [0006]    In accordance with the general teachings of the present invention, a trocar system is provided with a transparent tip portion. The trocar system allows for penetration into the patient&#39;s laparoscopic cavity while also allowing visualization once an imaging device (e.g., a laparoscope) is inserted into the hollow shaft of the trocar. Attached to a distal end of the trocar shaft is a tip portion, which may be comprised of a transparent material, and which allows for general visualization upon penetration into the patient&#39;s laparoscopic cavity. The tip portion may include a conical shape with at least one blade (e.g., preferably two blades) protruding longitudinally along a peripheral surface thereof. The blades may be comprised of a metallic material, e.g., preferably similar to the trocar shaft material, and may be securely attached (e.g., preferably welded) to the trocar shaft. The transparent tip may be caged by the blades and the trocar&#39;s shaft and may also be glued to the blades and trocar shaft as well. The metallic blades provide numerous advantages, such as but not limited to, assisting in the penetration through the patient&#39;s abdominal wall, while at the same time securing the conical transparent tip portion to the trocar&#39;s shaft and thus reducing the risk of breakage and/or unintended detachment therefrom. 
         [0007]    The present invention also provides methods of securing the transparent tip portion to the trocar&#39;s shaft, e.g., using metallic blades. These arrangements allow for visualization through the trocar shaft while adding robust metallic blades and added security of the tip portion to the trocar shaft. 
         [0008]    In accordance with one embodiment of the present invention, a trocar system is provided, comprising: 
         [0009]    a shaft member having a bore formed at a distal end thereof; 
         [0010]    a tip member having a proximal portion and a distal portion, the tip member having an area defining a groove extending along a peripheral surface thereof, the proximal portion being at least partially receivable in the bore; and 
         [0011]    a cutting member being at least partially receivable in the groove, the cutting member being selectively operable to maintain the tip member and the shaft member in a fixed relationship to one another. 
         [0012]    In accordance with one aspect of this embodiment, the shaft member includes an area defining a slot formed at a distal portion thereof. 
         [0013]    In accordance with one aspect of this embodiment, the cutting member includes an engagement member selectively operable to engage the slot of the shaft member. 
         [0014]    In accordance with one aspect of this embodiment, when the cutting member is at least partially received in the groove, the engagement member extends above a top surface of the proximal portion of the tip member. 
         [0015]    In accordance with one aspect of this embodiment, the tip member is formed of a transparent material. 
         [0016]    In accordance with one aspect of this embodiment, the proximal portion of the tip member is conically shaped. 
         [0017]    In accordance with one aspect of this embodiment, the shaft member or the cutting member is comprised of a metallic material. 
         [0018]    In accordance with one aspect of this embodiment, the proximal portion of the tip member has an outer diameter less than an internal diameter of the bore of the shaft member. 
         [0019]    In accordance with one aspect of this embodiment, the proximal portion of the tip member has an outer diameter less than an external diameter of the distal portion of the shaft member so as to form an area defining a shoulder portion therebetween. 
         [0020]    In accordance with one aspect of this embodiment, the shoulder portion is selectively operable to abut against the distal end of the shaft member so as to prevent further movement of the proximal portion of the tip member into the bore. 
         [0021]    In accordance with a second embodiment of the present invention, a trocar system is provided, comprising: 
         [0022]    a shaft member having a bore formed at a distal end thereof, the shaft member having an area defining a slot formed at a distal portion thereof; 
         [0023]    a tip member being formed of a transparent material and having a proximal portion and a distal portion, the tip member having an area defining a groove extending along a peripheral surface thereof, the proximal portion being at least partially receivable in the bore; and 
         [0024]    a cutting member being at least partially receivable in the groove, the cutting member having an engagement member selectively operable to engage the slot of the shaft member, the engagement member being selectively operable to maintain the tip member and the shaft member in a fixed relationship to one another. 
         [0025]    In accordance with one aspect of this embodiment, when the cutting member is at least partially received in the groove, the engagement member extends above a top surface of the proximal portion of the tip member. 
         [0026]    In accordance with one aspect of this embodiment, the proximal portion of the tip member is conically shaped. 
         [0027]    In accordance with one aspect of this embodiment, the shaft member or the cutting member is comprised of a metallic material. 
         [0028]    In accordance with one aspect of this embodiment, the proximal portion of the tip member has an outer diameter less than an internal diameter of the bore of the shaft member. 
         [0029]    In accordance with one aspect of this embodiment, the proximal portion of the tip member has an outer diameter less than an external diameter of the distal portion of the shaft member so as to form an area defining a shoulder portion therebetween. 
         [0030]    In accordance with one aspect of this embodiment, the shoulder portion is selectively operable to abut against the distal end of the shaft member so as to prevent further movement of the proximal portion of the tip member into the bore. 
         [0031]    In accordance with a third embodiment of the present invention, a trocar system is provided, comprising: 
         [0032]    a shaft member having an area defining a throughbore formed therethrough, the throughbore extending from a proximal opening to a distal opening of the shaft member, the shaft member having a cutting member formed at, and extending away from, a distal portion thereof; 
         [0033]    a tip member having a proximal portion and a distal portion, the tip member having an area defining a groove extending along a peripheral surface thereof, the tip portion being receivable in the proximal opening of the through bore such that the distal portion of the tip portion is selectively operable to extend at least partially past the distal opening; and 
         [0034]    wherein the cutting member is at least partially receivable in the groove, the cutting member being selectively operable to maintain the tip member and the shaft member in a fixed relationship to one another. 
         [0035]    In accordance with one aspect of this embodiment, the tip member is formed of a transparent material. 
         [0036]    In accordance with one aspect of this embodiment, the proximal portion of the tip member is conically shaped. 
         [0037]    In accordance with one aspect of this embodiment, the shaft member or the cutting member is comprised of a metallic material. 
         [0038]    Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0039]    Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
           [0040]      FIG. 1  illustrates a perspective view of a trocar system showing the underside of the handle portion, in accordance with a first embodiment of the present invention; 
           [0041]      FIG. 2  illustrates a perspective view of a trocar system, in accordance with a second embodiment of the present invention; 
           [0042]      FIG. 3  illustrates a perspective view of a trocar system showing a partial cutaway view of the shaft portion, in accordance with a third embodiment of the present invention; 
           [0043]      FIG. 4  illustrates a perspective view of a hollow top tip portion, in accordance with a fourth embodiment of the present invention; 
           [0044]      FIG. 5  illustrates a side view of a tip portion, in accordance with a fifth embodiment of the present invention; 
           [0045]      FIG. 6  illustrates a perspective view of a solid top tip portion, in accordance with a sixth embodiment of the present invention; 
           [0046]      FIG. 7  illustrates a perspective view of a cutting member, in accordance with a seventh embodiment of the present invention; 
           [0047]      FIG. 8  illustrates a detail view of a tip portion/cutting member tandem or assembly, in accordance with an eighth embodiment of the present invention; 
           [0048]      FIG. 9  illustrates a cutaway detail view of a tip portion/cutting member tandem or assembly, in accordance with a ninth embodiment of the present invention; 
           [0049]      FIG. 10  illustrates a perspective view of a shaft portion, in accordance with a tenth embodiment of the present invention; 
           [0050]      FIG. 11  illustrates a detail view of a slot formed in a shaft portion, in accordance with an eleventh embodiment of the present invention; 
           [0051]      FIG. 12  illustrates a top perspective view of a handle portion, in accordance with a twelfth embodiment of the present invention; 
           [0052]      FIG. 13  illustrates a bottom perspective view of a handle portion, in accordance with a thirteenth embodiment of the present invention; 
           [0053]      FIG. 14  illustrates a perspective view of a cannula system, in accordance with a fourteenth embodiment of the present invention; 
           [0054]      FIG. 15  illustrates a perspective view of a combined trocar/cannula system, in accordance with a fifteenth embodiment of the present invention; 
           [0055]      FIG. 16  illustrates a perspective view of a first alternative hollow top tip portion, in accordance with a sixteenth embodiment of the present invention; 
           [0056]      FIG. 17  illustrates a perspective view of a first alternative cutting member, in accordance with a seventeenth embodiment of the present invention; 
           [0057]      FIG. 18  illustrates a detail view of a first alternative tip portion/cutting member tandem or assembly, in accordance with an eighteenth embodiment of the present invention; 
           [0058]      FIG. 19  illustrates a perspective view of a first alternative solid top tip portion, in accordance with a nineteenth embodiment of the present invention; 
           [0059]      FIG. 20  illustrates a perspective view of a second alternative hollow top tip portion, in accordance with a twentieth embodiment of the present invention; 
           [0060]      FIG. 21  illustrates a perspective view of a second alternative cutting member, in accordance with a twenty-first embodiment of the present invention; 
           [0061]      FIG. 22  illustrates a detail view of a second alternative tip portion/cutting member tandem or assembly, in accordance with an twenty-second embodiment of the present invention; 
           [0062]      FIG. 23  illustrates a perspective view of a second alternative solid top tip portion, in accordance with a twenty-third embodiment of the present invention; 
           [0063]      FIG. 24  illustrates a perspective view of a third alternative hollow top tip portion, in accordance with a twenty-fourth embodiment of the present invention; 
           [0064]      FIG. 25  illustrates a perspective view of a third alternative cutting member, in accordance with a twenty-fifth embodiment of the present invention; 
           [0065]      FIG. 26  illustrates a detail view of a third alternative tip portion/cutting member tandem or assembly, in accordance with an twenty-sixth embodiment of the present invention; 
           [0066]      FIG. 27  illustrates a perspective view of a third alternative solid top tip portion, in accordance with a twenty-seventh embodiment of the present invention; 
           [0067]      FIG. 28  illustrates a perspective view of a fourth alternative cutting member, in accordance with a twenty-eighth embodiment of the present invention; 
           [0068]      FIG. 29  illustrates a detail view of a fourth alternative tip portion/cutting member tandem or assembly, in accordance with an twenty-ninth embodiment of the present invention; 
           [0069]      FIG. 30  illustrates a perspective view of a fifth alternative cutting member, in accordance with a thirtieth embodiment of the present invention; and 
           [0070]      FIG. 31  illustrates a detail view of a fifth alternative tip portion/cutting member tandem or assembly, in accordance with a thirty-first embodiment of the present invention. 
       
    
    
       [0071]    The same reference numerals refer to the same parts throughout the various Figures. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0072]    The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, or uses. 
         [0073]    Referring generally to the Figures, and more specifically to  FIGS. 1-3 , there is shown a trocar system generally at  10 . The system  10  primarily includes a tip portion  100 , a shaft portion  200  and an optional handle portion  300 . 
         [0074]    Referring specifically to  FIGS. 4 and 5 , the tip portion  100  primarily includes a tip member  400  which is preferably comprised of a transparent material, such as but not limited to plastics, such as but not limited to acrylics, polycarbonates, and/or the like, as well as glass and/or the like. By way of a non-limiting example, the chosen material for the tip member  400  should be one that is able to at least partially transmit light (e.g., from any source) therethrough such that the surgeon can adequately visualize the patient&#39;s laparoscopic cavity, e.g., with the aid of an illuminating device. 
         [0075]    Although the tip portion member  400  is shown as being substantially conical in shape, it should be appreciated that other shapes and/or configurations may be practiced with the present invention. 
         [0076]    The tip member  400  may include a lower conical portion  402  and an upper cylindrical portion  404 . A stop or shoulder portion  406  is defined at the interface between the lower conical portion  402  and an upper cylindrical portion  404 . In this view, at least a portion of the lower conical portion  402  has a larger outer diameter than that of the upper cylindrical portion  404 . The lower conical portion  402  includes an area defining a groove  408  (the intended purpose of which will be described herein) extending from the terminus  410  up along the peripheral surface  412  thereof and further extending along the peripheral surface  414  of the upper cylindrical portion  404 . The groove  408  terminates at the top portion  416  of the upper cylindrical portion  404 . The upper cylindrical portion  404  includes an area defining a bore  418  formed therein, the bore  418  originating at the top portion  416  and extending downwardly towards and/or into the lower conical portion  402 , thus providing an essentially hollow tip member  400 . The exact depth of the bore  418  is not thought to be critical to the success of the invention; however, it may provide a passageway for an illuminating device (not shown) to be placed near and/or proximate to an internal surface of the lower conical portion  402 . 
         [0077]    Alternatively, as shown in  FIG. 6 , the bore  418  can be eliminated altogether, thus resulting in a tip member  400   a  having a solid lower conical portion  402   a  and/or upper cylindrical portion  404   a . By way of a non-limiting example, the chosen material for the tip member  400   a  should be one that is able to transmit light (from any source) therethrough such that the surgeon can adequately visualize the patient&#39;s laparoscopic cavity, e.g., with the aid of an illuminating device. 
         [0078]    Referring specifically to  FIGS. 7-9 , a cutting member  500  is shown. By way of a non-limiting example, the cutting member  500  may be comprised of a metallic material, e.g., a biocompatible metallic material such as but not limited to stainless steel and/or the like. 
         [0079]    The cutting member  500  is intended to engage and interoperate with the tip portion  400 . The cutting member  500  primarily includes a lower end portion  502  having a rounded or blunted terminus  504 . Extending upwardly from the terminus  504  is at least one, and more preferably at least two spaced and opposed arm members  506 ,  508 , respectively. The arm members  506 ,  508 , respectively, may be provided with one or more blade surfaces  510 ,  512 ,  514 ,  516 , respectively, formed thereon. One or more of the blade surfaces  510 ,  512 ,  514 ,  516 , respectively, may be blunted and/or sharpened. The arm members  506 ,  508 , respectively, extend further upwardly towards a pair of spaced and opposed shoulder surfaces  518 ,  520 , respectively (the intended purpose of which will be described herein). A pair of finger members  522 ,  524 , respectively (the intended purpose of which will be described herein), extend upwardly from the shoulder surfaces  518 ,  520 , respectively. At the terminus of the finger members  522 ,  524 , respectively, a pair of spaced and opposed engagement members  526 ,  528 , respectively (the intended purpose of which will be described herein), extend outwardly therefrom in a perpendicular orientation to the finger members  522 ,  524 , respectively. 
         [0080]    By way of a non-limiting example, to engage the cutting member  500  to the tip portion  400 , the two components are brought into contact with one another such that the terminus  504  of the cutting member  500  abuts against the terminus  410  whereby the lower end portion  502  is received, at least partially, into the groove  408 . In this manner, the arm members  506 ,  508 , respectively, the shoulder surfaces  518 ,  520 , respectively, and finger members  522 ,  524 , respectively, are likewise also received, at least partially, into their respective corresponding portions of the groove  408  as well. In this manner, a tip portion  400 /blade member  500  tandem or assembly may be formed. 
         [0081]    Once the cutting member  500  is engaged to the tip portion  400 , at least a portion of the finger members  522 ,  524 , respectively, preferably extends above the top portion  416  of the upper cylindrical portion  404  such that the engagement members  526 ,  528 , respectively, also extend above the top portion  416  of the upper cylindrical portion  404  and are able to flex either in an inboard (i.e., inwardly) and/or outboard (i.e., outwardly) direction, the intended purpose of which will be described herein. 
         [0082]    By way of a non-limiting example, in order to prevent the inadvertent disengagement of the cutting member  500  from the tip portion  400 , a chemical and/or mechanical fastening system can be employed. For example, an adhesive, glue, and/or the like can be used to fasten the cutting member  500  to the tip portion  400 . The adhesive, glue, and/or the like can be applied to either (or both) the cutting member  500  and/or the tip portion  400  before engagement thereto, or alternatively, the adhesive, glue, and/or the like can be applied to either (or both) the cutting member  500  and/or the tip portion  400  after engagement thereto. 
         [0083]    Referring specifically to  FIGS. 1-3  and  8 - 11 , the shaft portion  200  primarily includes an elongated, hollow cylindrical tube member  202 . By way of a non-limiting example, the shaft portion  200  may be comprised of a metallic material, e.g., a biocompatible metallic material such as but not limited to stainless steel and/or the like. 
         [0084]    The tube member  202  includes a proximal portion  204  and a distal portion  206 . An area defining a through bore  208  interconnects a proximal opening  209  and a distal opening  210 . At the distal portion  206 , there may be provided an area defining a pair of spaced and opposed slots  212 ,  214 , respectively (the intended purpose of which will be described herein). 
         [0085]    By way of a non-limiting example, to engage the tip portion  400 /cutting member  500  tandem or assembly to the distal portion  206  of the shaft portion  200 , the two components are brought into contact with one another such that the engagement members  526 ,  528 , respectively, and finger members  522 ,  524 , respectively, are received into the distal opening  210 . As the tip portion  400 /cutting member  500  tandem and finger members  522 ,  524 , respectively, are further received into the distal opening  210 , at least a portion of the upper cylindrical portion  404  is then received into the distal opening  210 . Preferably, the upper cylindrical portion  404  has an external diameter less than an internal diameter of the distal opening  210  such that the upper cylindrical portion  404  can relatively easily be received therein. As the upper cylindrical portion  404  is further received into the distal opening  210 , the shoulder portion  406  of the upper cylindrical portion  404  abuts against the end portion  210   a  of the distal opening  210 , thus preventing further advancement of the tip portion  400 /cutting member  500  tandem relative to the shaft portion  200 . At this point, the engagement members  526 ,  528 , respectively, may be proximate to the slots  212 ,  214 , respectively, such that the engagement members  526 ,  528 , respectively, may “snap” into the slots  212 ,  214 , respectively, thus interconnecting the tip portion  400 /cutting member  500  tandem or assembly and the shaft portion  200 . If the tip portion  400 /cutting member  500  tandem or assembly was misaligned relative to the distal opening  210  during the insertion procedure, the tip portion  400 /cutting member  500  tandem or assembly can simply be rotated until the engagement members  526 ,  528 , respectively, align with and then snap into the slots  212 ,  214 , respectively. It should be appreciated that the groove  408  preferably has a depth sufficient to permit the flexure of the arm members  506 ,  508 , respectively, and/or finger members  522 ,  524 , respectively, in an inboard direction (e.g., inwardly) before they snap into the slots,  212 ,  214 , respectively. 
         [0086]    By way of a non-limiting example, in order to prevent the inadvertent disengagement of the tip portion  400 /cutting member  500  tandem or assembly and the shaft portion  200 , a chemical and/or mechanical fastening system can be employed. For example, an adhesive, glue, and/or the like can be used to fasten the shoulder portion  406  of the upper cylindrical portion  404  to the end portion  210   a  of the distal opening  210 . The adhesive, glue, and/or the like can be applied to either (or both) the shoulder portion  406  of the upper cylindrical portion  404  to the end portion  210   a  of the distal opening  210  before engagement thereto, or alternatively, the adhesive, glue, and/or the like can be applied to either (or both) the shoulder portion  406  of the upper cylindrical portion  404  to the end portion  210   a  of the distal opening  210  after engagement thereto. Furthermore, the engagement members  526 ,  528 , respectively, may be glued to the slots  212 ,  214 , respectively, or alternatively, the engagement members  526 ,  528 , respectively, may be welded to the slots  212 ,  214 , respectively. 
         [0087]    Referring specifically to  FIGS. 1-3 ,  12  and  13 , the handle portion  300  primarily includes a hub member  302  having an area defining a centrally located through bore  304  formed therein. At least one wall member  305  (and preferably at least two or more) extends from the cylindrical wall  304   a  of the bore  304  to provide enhanced structural stability to the hub member  302 . A pair of spaced and opposed arm members  306 ,  308 , respectively, extends outwardly and downwardly from the hub member  302  (the intended purpose of which will be described herein). A port member  310  may be formed on a top surface  312  of the hub member  302  to allow instrumentation to pass through the port member  310  and the through bore  304 . Thus, the port member  310  and the through bore  304  are preferably coaxially aligned with one another. The proximal portion  204  of the tube member  202  is preferably joined to the through bore  304  by any number of methods, including but not limited to chemical and/or mechanical attachment, e.g., gluing, press fit, frictional engagement, and/or the like. Once the tube member  202  is fastened to the through bore  304 , the port member  310 , the through bore  304 , and the through bore  208  are preferably coaxially aligned with one another to allow instrumentation to pass there through. 
         [0088]    Referring specifically to  FIGS. 14 and 15 , the trocar system  10  may be used in conjunction with a cannula system  600 . The cannula system  600  primarily includes a handle portion  602  with a pair of spaced and opposed slot members  604 ,  606 , respectively, and an elongated, hollow tube portion  608  extending from the handle portion  602 . To engage the trocar system  10  with the cannula system  600 , the tip portion  100  is introduced into the top of the through bore  610  of the tube member and advanced therethrough until the tip portion  100  protrudes out through the distal portion  612  of the tube member  600 . As this occurs, the arm members  306 ,  308 , respectively, of the hub member  302  engage the slot members  604 ,  606 , respectively, of the handle portion  602  so as to releasably interconnect the two components. Each of the arm members  306 ,  308 , respectively, may be provided with shoulder members  306   a ,  308   a , respectively, abut against the underside surfaces  604   a ,  606   a , respectively, of the slot members  604 ,  606 , respectively, to prevent inadvertent disengagement of the arm members  306 ,  308 , respectively, from the slot members  604 ,  606 , respectively. 
         [0089]    Several alternative embodiments are also provided with respect to modifications of the tip portions, cutting members and shaft portions. 
         [0090]    Referring specifically to  FIGS. 16-18 , there is shown a hollow tip portion  700 , wherein the lower terminus portion  702  does not include an area defining a groove  704 . Accordingly, two separate cutting members  800 ,  802 , respectively, are needed (as opposed to a single unitary cutting member). As with the previous embodiments, the engagement members  804 ,  806 , respectively, may engage slots  900 ,  902 , respectively, formed on the distal portion  904  of the shaft portion  906 . Referring specifically to  FIG. 19 , a solid version  1000  of the tip portion  700  is shown. 
         [0091]    Referring specifically to  FIGS. 20-22 , there is shown a hollow tip portion  1100 , wherein the lower terminus portion  1102  does include an area defining a groove  1104 . Accordingly, only one cutting member  1200  is needed (as opposed to two cutting members). Distinct from the previous embodiments, there are no engagement members provided on the cutting member fingers  1202 ,  1204 , respectively, that may engage slots  1300 ,  1302 , respectively, formed on the distal portion  1304  of the shaft portion  1306 . In this case, a weld may be formed between the cutting member fingers  1202 ,  1204 , respectively, and the slots  1300 ,  1302 , respectively (alternatively, an adhesive may be used to join the two portions together). Referring specifically to  FIG. 23 , a solid version  1400  of the tip portion  1100  is shown. 
         [0092]    Referring specifically to  FIGS. 24-26 , there is shown a hollow tip portion  1500 , wherein the lower terminus portion  1502  does include an area defining a groove  1504 . Additionally, the tip portion  1500  does not include a shoulder portion, thus allowing the tip portion  1500  to be introduced down the proximal portion of the shaft portion such that it drops down the shaft portion and partially exits out through the distal portion  1700 . However, in this embodiment a separate cutting member is not provided; but rather, the cutting member  1600  is formed from the distal portion  1700  of the shaft portion  1702  (in this view there are two cutting members  1600   a ,  1600   b , respectively). In this case, the two cutting members  1600   a ,  1600   b , respectively, may be pushed (if needed) into the groove  1504  and secured in place by use of an adhesive and/or the like. Referring specifically to  FIG. 27 , a solid version  1700  of the tip portion  1500  is shown. 
         [0093]    Referring specifically to  FIGS. 28 and 29 , there is shown a variation of the embodiment depicted in  FIGS. 24-27 . In this embodiment, the tip portion  1800  does not include a shoulder portion, thus allowing the tip portion  1800  to be introduced down the proximal portion of the shaft portion  1900  such that it drops down the shaft portion  1900  and partially exits out through the distal portion  1902 . Again, the cutting member  2000  is formed from the distal portion  1902  of the shaft portion  1900  (in this view there are two cutting members  2000   a ,  2000   b , respectively). However, the cutting members  2000   a ,  2000   b , respectively, include machined edges forming cutting surfaces thereon. Again, in this case, the two cutting members  2000   a ,  2000   b , respectively, may be pushed (if needed) into the groove (not shown) of the tip portion  1800  and secured in place by use of an adhesive and/or the like. 
         [0094]    Referring specifically to  FIGS. 30 and 31 , there is shown a variation of the embodiment depicted in  FIGS. 28 and 29 . In this embodiment, the tip portion  2100  does not include a shoulder portion, thus allowing the tip portion  2100  to be introduced down the proximal portion of the shaft portion  2200  such that it drops down the shaft portion and partially exits out through the distal portion  2202 . Again, the cutting member  2300  is formed from the distal portion  2202  of the shaft portion  2200  (in this view there are two cutting members  2300   a ,  2300   b , respectively). However, the cutting members  2300   a ,  2300   b , respectively, include blunt rounded terminal portions  2300   c ,  2300   d , respectively, formed thereon. Again, in this case, the two cutting members  2300   a ,  2300   b , respectively, may be pushed (if needed) into the groove (not shown) of the tip portion  2100  and secured in place by use of an adhesive and/or the like. 
         [0095]    While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.