Surgical cutting instrument

Abstract: A surgical cutting instrument (100) is disclosed for percutaneously debulking tissue through an access sheath commonly used in minimally invasive laparoscopic or endoscopic surgical procedures. The cutting instrument includes an inner rotary member tube (101) having a cutting edge (105) at the distal end thereof for cutting and slicing tissue. The distal end of the cutting member tube extends from the distal end of a stationary sheath (108) which prevents tissue from wrapping around the inner cutting member tube. The inner cutting member tube includes a hollow passageway (104) for suctioning and aspirating tissue and fluid through the tube and into a collection chamber (212) or out through a vacuum or suction line (216) attached thereto. The instrument further includes an outer safety shield (201) having a rounded distal end (203) for preventing the puncture of a surgical tissue bag or from unintentionally cutting tissue by the attending physician. The outer shield has a channel (207) across the distal end through the hollow passageway therein for feeding tissue into the cutting edge and controlling the vacuum applied to the tissue. Vacuum or suction control ports (210) are included at the proximal end of the inner cutting member tube and stationary sheath for also controlling the amount of vacuum or suction applied to the tissue. The surgical cutting instrument includes a control handle (118) for grasping by the physician. A removable collection chamber (212) is connected to a coupler connected to the stationary sheath for collecting tissue therein. The inner cutting member tube extends through the collection chamber to a drive motor (123) or to a remotely positioned rotary drive mechanism. A vacuum line is attached to the collection chamber for drawing tissue and fluid through the inner cutting member tube and into the collection chamber.

Description: This invention relates to percutaneous surgical cutting instruments. One of the major problems associated with minimally invasive surgery is percutaneously debulking or reducing a large tissue volume such as with a cyst, tumour, or an organ for removal through an access sheath. A number of instruments, such as that described in U.S. Patent No. 4,274,414, are presently available in which a side port and/or a partial opening at the distal end of a cutting tube are rotated to shear by a scissor-like action and aspirate bone and cartilage through a lumen of the instrument. These side ports or partially open-ended cutting instruments are inefficient in debulking large volumes of soft tissue due to their limited access cutting surfaces, and they cannot core soft tissue. They have limited control and directionality due to the complex angles of use. U.S. 3,990,453 discloses an instrument as defined in the preamble of claim 1. According to the present invention there is provided an instrument as defined in the characterising portion of claim 1. The outer support tube or stationary sheath provides a protective guard for the inner member by limiting the lateral contact of the inner member with tissue, which advantageously prevents the wrapping of tissue around the inner rotary cutting member. The sheath also prevents unwanted tearing or binding of the tissue around the inner cutting member. Wrapped around tissue would otherwise limit the control and directionality of the cutting member. The cutter provides continual and head-on controlled cutting, slicing or debulking of tissue. The cutting edge of the inner rotating tube is radiused to cut soft tissue but yet not cut a surgical tissue bag, which may be brought in contact with the inner rotary cutting member. In a second embodiment, a variable size access channel acts as a valve to control aspiration of fluid and tissue through the hollow passageway of the inner cutting member. Vacuum or suction control ports at the proximal end of the inner member and intermediately positioned stationary sheath also regulate the amount of vacuum or suction that is applied to the passageway of the inner cutting member for aspirating tissue or fluid therethrough. The outer safety shield is longitudinally extendable and withdrawable for controlling the size of the side access channel. A handle at the proximal end of the cutting instrument allows directional control of the instrument along with providing manual control of the instrument and the outer shield. The word "slicing" includes within its meanings, the operation of sawing or cutting or slicing, but not a scissors-type action. Brief description of the drawings FIG.1 depicts an illustrative embodiment surgical cutting instrument; FIG.2 depicts a modified form of the instrument; and FIG.3 is a partial cross-sectional view of FIG.2. Depicted in FIG.1 is an illustrative surgical cutting instrument 100 for percutaneously debulking and cutting tissue through an access sheath that is commonly utilized in minimally invasive surgery. A trocar sheath is normally pushed through the skin and subcutaneous tissue layers into a cavity of the patient during, for example, an endoscopic or laparoscopic procedure. The cutting instrument is inserted through the sheath or into a percutaneously positioned surgical tissue bag for debulking or reducing large tissue volumes such as cysts, tumours, organs or the like. A concurrently filed application discloses a preferred surgical tissue bag. The cutting instrument comprises an inner elongated member tube 101 having a distal end 102, a proximal end 103, and a hollow passageway 104 preferably extending longitudinally therebetween. Positioned at the distal end of the inner member tube is a rotary cutting edge 105 that is circumferentially positioned thereabout. The cutting edge includes radius 106 extending from the hollow passageway to an outer surface 107 of the inner member tube. The radiused edge reduces the possibility of puncturing a surgical tissue bag or unintentionally cutting tissue. Surrounding the rotary cutting tube is elongated stationary sheath 108 connected to coupler 109. The stationary sheath has a distal end 110, a proximal end 111, and a hollow passageway 112 positioned longitudinally therebetween. Distal end 112 includes a bevel 113 extending circumferentially therearound for preventing the tearing or ripping of tissue coming in contact therewith. By way of example, inner cutting member tube is a stainless steel tube having a 0.76 cms (0.3") diameter with a wall thickness of 0.0254 cms (0.01"). The stationary sheath is also a stainless steel tube having a 0.838 cms (0.33") outside diameter with a 0.0254 cms (0.01") wall thickness. The lengths of the inner cutting member tube and the stationary sheath range in length preferably from 5-10cm. The proximal end 111 of stationary sheath 108 is connected to the distal end 114 of coupler 109. A hollow passageway 115 extends through the coupler to the proximal end 116 thereof where rotary drive mechanism 117 is connected thereto. By way of example, rotary drive mechanism 117 includes a well-known DC electric motor 123 connected to the proximal end 103 of rotary inner member tube 101. Alternatively, drive mechanism 123 may include a casing and well-known bearings for applying air to a turbine also positioned at the proximal end of the inner cutting member tube. Other well-known means of providing a rotary motion to the inner cutting member are also contemplated. A handle 118 extends radially from the coupler to provide manual control of the entire cutting instrument by the attending physician. An evacuation port 119 extends radially from hollow coupler passageway 115 for suctioning tissue and other fluid from side proximal evacuation port 120 of inner cutting member tube 101. A well-known connector 121 provides means for fastening a vacuum line or suction tube 122 to coupler 109. In FIG.2 instrument 100 has an outer safety shield 201 positioned about sheath 108 and tube 101. Shield 201 includes a proximal end 202, a rounded distal end 203, and a hollow passageway 204 positioned and extending longitudinally therebetween. The shield is sized for inserting the stationary sheath and the inner cutting member tube within passageway 204. By way of example, the outer shield comprises a stainless steel tube having a 0.86 cms (0.34") outside diameter with a wall thickness of 0.038 cms (0.015"). The distal end 203 of the outer shield is rounded to prevent unintentional cutting of tissue and puncturing the surgical tissue bag should such be utilized in the surgical procedure. Extending radially from the proximal end is a control arm 205 having an eyelet ring 206 at the proximal end thereof for slideably controlling the position of the outer shield with respect to stationary sheath 108 and inner cutting member tube 101. The attending physician typically inserts his index finger therein while the rest of the hand grasps control handle 118. Positioned about the distal end 203 of the outer shield is access channel 207 that extends laterally across the shield tube and through hollow passageway 204. Face edge 208 of the channel is moved by ring 206 and acts as a jaw for grasping or guiding tissue and feeding it into cutting edge 105 of the inner cutting member tube. In this modified embodiment, which is suitable for cutting large portions of tissue, distal end 102 of the inner cutting member tube is bevelled to provide a sharper cutting edge 105. A plurality of vacuum control ports 209 are positioned longitudinally along the length of stationary sheath 108. A plurality of vacuum access ports 210 along tube 101 are correspondingly positioned with respect to access ports 209 of the stationary sheath to control the amount of vacuum applied to the distal end of the inner cutting member tube. As the outer shield 201 is longitudinally moved or slides along stationary sheath 108, the vacuum control access ports are either opened or covered up to allow respectively more or less suction to be applied to the distal end of the inner cutting member tube. As depicted in FIGS.2 and 3, coupler 211 has been modified to receive a detachable tissue collection chamber 212. Handle 118 is fixedly attached to coupler 211 as is stationary sheath 108. The collection chamber is of a cylindrical form including a cylindrical collection screen 213 for collecting tissue as vacuum is applied via evacuation port 214, vacuum connector 215, and vacuum tube 216. The inner cutting member tube extends longitudinally through the collection chamber to rotary drive mechanism 217 which is part of the proximal end of the collection chamber. The proximal end of the inner rotary cutting member tube is connected to a remote source of rotary power via rotary power line 218. The inner cutting member tube is positioned within the collection chamber preferably by two bearing flanges and a slotted end. The rotary drive mechanism may include a remote source of power or may be integrally incorporated into the cutting instrument (as in FIG.1). Extending longitudinally from coupler 211 is elongated stop arm 219 having a cross member 220 positioned at the distal end thereof. The built-up distal end of radial control arm 205 includes a longitudinal slot or channel 221 formed therein for slideably receiving stop arm 219. Cross member 220 limits the longitudinal motion of the outer shield when control arm 205 engages cross member 220. The distal end of the control arm is moveable as shown by arrow 222 to remove the outer shield for cleaning. The distal end of the cutting instrument may include serrated teeth for providing any number of different cutting or slicing actions. The rounded distal end of the outer shield may be devised to include a series of rounded wires to permit penetration through soft tissue to permit cutting and slicing by the inner cutting member tube. Such a wire cage arrangement would also prevent puncture of a surgical tissue bag should one be desired to be used by the physician.

Claims: A surgical cutting instrument comprising an outer support tube (108), an inner elongated tubular member (101) rotatably mounted within the support tube, means for enabling the inner member to be rotated within the support tube, means (104) for removing tissue via the distal end of the inner member, the distal end of the said member when in an operative condition extending beyond the distal end of the support tube, and the distal end of the inner member having a peripheral cutting or slicing edge (105) for cutting through tissue when the member is rotated, characterised in that the cutting edge is at the inner edge of the wall of the inner tubular member, and in that the outer edge of the wall of the inner tubular member adjacent the cutting edge is rounded or radiused (106) in the direction of the longitudinal axis of said inner tubular member. The instrument of claim 1, characterised in that the removing means includes side port means positioned along the inner member and a hollow passageway within the inner member and extending at least from the side port means to the distal end thereof. The instrument of claim 1 or 2, further characterised by a coupler (109) connected to the support tube and having a first hollow passageway extending longitudinally therethrough and a side port (119) extending radially from said first passageway, and forming part of the removing means. The instrument of claim 3, characterised in that the coupler is connected to the rotation means, and in that the latter includes an electric motor (123). The instrument of claim 3 or 4, further characterised by an outer elongated safety shield (201) positioned about the support tube, the outer safety shield being longitudinally extendable and withdrawable for controlling the size of the side access channel, and a hollow passageway positioned longitudinally therebetween and sized for insertion of said sheath and said inner member, the shield having a distal end with a predetermined puncture-resistant shape (203), and in that the side port extends from the hollow passageway thereof and opening exterior to an outer surface of said shield. The instrument of claim 5, characterised in that said outer shield includes a control arm extending radially therefrom and serving to control movement of the shield relative to the support tube. The instrument of claim 5, characterised in that the support tube and the inner member each includes a plurality of ports extending therethrough, and in that movement of the shield exposes certain of the parts to control evacuation of the inner tube. The instrument of claim 5, characterised in that said side port includes a channel extending laterally through said shield and said passageway thereof and forming facing edges therein. The instrument of claim 5, characterised in that the coupler includes a tissue collection chamber (212), forming part of the said removing means. The instrument of claim 6, characterised in that the outer shield includes a hub attached about said proximal end thereof, and in that an elongated stop member extends from said hub longitudinally alogside said outer shield. The instrument of claim 11, characterised in that said control arm includes a channel therein for insertion of the elongated stop member.

Inventors: PINGLETON EDWARD DUANE, THOMSON PAUL GUY, PINGLETON, EDWARD DUANE, THOMSON, PAUL GUY
Applicants: VANCE PRODUCTS INC, VANCE PRODUCTS INCORPORATED D/B/A COOK UROLOGICAL INCORPORATED
Application year: 1991
Main classification: A61B17
IPC codes: A61B17, A61M1