Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
  • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
  • A61B18/14—Probes or electrodes therefor
  • A61B18/1442—Probes having pivoting end effectors, e.g. forceps
  • A61B18/1445—Probes having pivoting end effectors, e.g. forceps at the distal end of a shaft, e.g. forceps or scissors at the end of a rigid rod
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
  • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
  • A61B18/14—Probes or electrodes therefor
  • A61B18/1402—Probes for open surgery
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B2017/00831—Material properties
  • A61B2017/0088—Material properties ceramic
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/28—Surgical forceps
  • A61B17/29—Forceps for use in minimally invasive surgery
  • A61B2017/2926—Details of heads or jaws
  • A61B2017/2945—Curved jaws
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B2018/00053—Mechanical features of the instrument of device
  • A61B2018/00059—Material properties
  • A61B2018/00071—Electrical conductivity
  • A61B2018/00083—Electrical conductivity low, i.e. electrically insulating
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B2018/00053—Mechanical features of the instrument of device
  • A61B2018/00107—Coatings on the energy applicator
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
  • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
  • A61B18/14—Probes or electrodes therefor
  • A61B2018/1405—Electrodes having a specific shape
  • A61B2018/1412—Blade
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
  • A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
  • A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
  • A61B18/14—Probes or electrodes therefor
  • A61B2018/1405—Electrodes having a specific shape
  • A61B2018/1425—Needle
  • A61B2018/1432—Needle curved

Definitions

• the invention relates to endoscopic surgical instruments. More particularly, the invention relates to endoscopic surgical scissors having scissor blades made out of a combination of conductive and non-conductive materials.
• the invention has particular use with respect to bipolar endoscopic cautery.
• endoscopic instruments is to be understood in its broadest sense to include laparoscopic, arthroscopic, and neurological instruments, as well as instruments which are inserted through an endoscope.
• endoscopic surgery is widely practiced throughout the world today and its acceptance is growing rapidly.
• endoscopic/laparoscopic surgery involves one or more incisions made by trocars where trocar tubes are left in place so that endoscopic surgical tools may be inserted through the tubes.
• a camera, magnifying lens, or other optical instrument is often inserted through one trocar tube, while a cutter, dissector, or other surgical instrument is inserted through the same or another trocar tube for purposes of manipulating and/or cutting the internal organ.
• endoscopic surgical instruments generally comprise a slender tube containing a push rod which is axially movable within the tube by means of a handle or trigger-like actuating means.
• An end effector is provided at the distal end of the tube and is coupled to the push rod by means of a clevis so that axial movement of the push rod is translated to rotational or pivotal movement of the end effector.
• End effectors may take the form of scissors, grippers, cutting jaws, forceps, and the like. Because of their very small size and the requirements of strength and/or sharpness, end effectors are difficult to manufacture and are typically formed of forged stainless steel. As such, they form an expensive portion of the endoscopic instrument.
• Monopolar electrosurgical instruments employ the instrument as an electrode, with a large electrode plate beneath and in contact with the patient serving as the second electrode. High frequency voltage spikes are passed through the instrument to the electrode (i.e., end effector) of the endoscopic instrument to cause an arcing between the instrument and the proximate tissue of the patient. The current thereby generated continues through the patient to the large electrode plate beneath the patient.
• Monopolar cautery has the disadvantage that the current flows completely through the patient.
• bipolar instruments In order to overcome the problems associated with monopolar cautery instruments, bipolar instruments have been introduced.
• bipolar electrosurgical instruments two electrodes which are closely spaced together are utilized to contact the tissue.
• one end effector acts as the first electrode
• the other end effector acts as the second electrode, with the end effectors being electrically isolated from each other and each having a separate current path back through to the handle of the instrument.
• the current flow is from one end effector electrode, through the tissue to be cauterized, to the other end effector electrode.
• U.S. Patent #3,651,811 to Hildebrandt describes a bipolar electrosurgical scissors having opposing cutting blades forming active electrodes.
• the described scissors enables a surgeon to sequentially coagulate the blood vessels contained in the tissue and then to mechanically sever the tissue with the scissor blades.
• the surgeon must first grasp the tissue with the scissor blades, energize the electrodes to cause hemostasis, de-energize the electrodes, and then close the scissor blades to sever the tissue mechanically. The scissors are then repositioned for another cut accomplished in the same manner.
• the bipolar electrosurgical scissors of Eggers comprise a pair of metal scissor blades which are provided with an electrically insulating material interposed between the shearing surfaces of the blades so that when the scissor blades are closed, the metal of one blade never touches the metal of the other blade; i.e., the insulating material provides the cutting edge and the shearing surface.
• a cautery current will pass from the top back edge of the bottom metal blade through the tissue which is to be cut and to the bottom back edge of the top metal blade directly in advance of the cutting action.
• the hemostasis preferentially occurs at a location just in advance of the cutting point which itself moves distally along the insulated cutting edges of the blades in order to sever the he ostatically heated tissue.
• the scissors may be maintained in a continuously energized state while performing the cutting.
• the Eggers patent describes various alternative embodiments of the bipolar scissors, including the use of metal blades with only one blade being insulated on its shearing surface, and the use of insulating blades with back surfaces coated with metal. Eggers teaches insulating the entire cutting edge and shearing surface of at least one blade.
• the endoscopic bipolar scissor blades of the present invention include a pair of metallic electrically conductive blades each having a cutting edge and an adjacent shearing surface. At least one of the blades is partially covered with an electrically insulating ceramic material which is preferably located along substantially the entire cutting edge of the blade and a relatively small portion of its shearing surface adjacent to the cutting edge. In an alternate embodiment of the invention, the ceramic covering constitutes a relatively larger portion of the shearing surface of the blade, but still not the entire shearing surface. The ceramic covering is preferably applied by masking the portion of the blade which is not to be covered and by spraying the masked blade with a ceramic vapor.
• the ceramic covering may also be formed by bonding a relatively thin piece of ceramic material to the shearing surface of the blade.
• at least one of the blades is provided with an insert receiving channel groove on a portion of its shearing surface adjacent to its cutting edge.
• a ceramic insert having a groove engaging tongue portion which is inserted into the channel groove of the scissor blade is used to form a ceramic cutting edge on the metallic blade.
• the scissor blades of the invention may be either curved or straight. Because the scissor blades are intended for use as part of an endoscopic instrument, each blade is preferably provided with a first hole which receives an axle or clevis pin around which the blades rotate. In addition, each blade is preferably provided with a pin or protrusion extending from a proximal or base portion of the blade. The pins are provided to receive links which couple the blades to an actuator mechanism. In use, as the scissor blades are moved relative to each other from the open to the closed position, the portions of their respective shearing surfaces which lie proximal of the distally moving point of engagement of the respective cutting edges are bowed apart from each other.
• the endoscopic bipolar cautery scissors instrument which utilizes the blades of the invention is substantially as is described in copending application U.S. Serial No. 08/284,793, the complete disclosure of which is hereby incorporated by reference herein, and utilizes a push rod assembly with two conductive push rods which are stabilized and insulated relative to each other.
• the distal ends of the push rods are coupled to the scissor blades by links.
• the proximal ends of the push rods extend through a handle and lever of the scissors instrument and present electrical cautery pins onto which a standard bipolar cautery plug can be mated.
• Figure 1 is a broken, partially transparent, partially sectional, side elevation view of an endoscopic bipolar scissors according to the invention
• Figure 2 is an enlarged side elevation view of a first non-insulated scissor blade according to the invention
• Figure 2a is a top view of the scissor blade of Figure 2;
• Figure 2b is an enlarged sectional view taken along line 2b-2b in Figure 2;
• Figure 3 is an enlarged side elevation view of a second insulated scissor blade according to the invention.
• Figure 3a is a top view of the scissor blade of Figure 3;
• Figure 3b is an enlarged sectional view taken along line 3b-3b in Figure 3 illustrating a first embodiment of the scissor blade of Figure 3;
• Figure 3c is a view similar to Figure 3b illustrating a second embodiment of the scissor blade of Figure 3;
• Figure 3d is a view similar to Figure 3 illustrating a third embodiment of the scissor blade of Figure 3;
• Figure 3e is an enlarged sectional view taken along line 3e-3e in Figure 4;
• Figure 4 is an enlarged transparent side view elevation view of the scissor blades of Figures 2 and 3 in an open position representing an early stage of a cutting operation;
• Figure 4a is an enlarged sectional view taken along line 4a-4a in Figure 4;
• Figure 5 is an enlarged transparent side elevation view of the scissor blades of Figures 2 and 3 in a closed position representing the final stage of a cutting operation;
• Figure 6 is an enlarged top view of the scissor blades of Figures 2 and 3 in a closed position representing the final stage of a cutting operation.
• an endoscopic bipolar scissors instrument 10 includes a proximal handle 12 with a manual lever actuator 14 pivotally coupled to the handle by a pivot pin 15.
• a hollow tube 16 is rotatably coupled to the handle 12 and is preferably rotatable about its longitudinal axis relative to the handle 12 through the use of a ferrule 18 such as described in detail in previously incorporated copending application Serial Number 08/284,793.
• a push rod assembly 20 extends through the hollow tube 16 and is coupled at its proximal end 22 to the manual lever actuator 14 as described in more detail in copending application Serial Number 08/284,793.
• the distal end of the tube 16 has an integral clevis 24 within which a pair of scissor blades 26, 28 are mounted on an axle screw 30.
• the distal end 23 of the push rod assembly 20 is coupled to the scissor blades 26, 28 so that reciprocal movement of the push rod assembly 20 relative to the tube 16 opens and closes the scissor blades 26, 28.
• the clevis 24 and the axle screw 30 are both provided with insulation as described in copending application Serial Number 08/284,793 so that the scissor blades 26, 28 are electrically insulated from each other at their coupling to the clevis.
• the presently preferred embodiment of the push rod assembly 20 includes a pair of stainless steel rods 32, 34 which are molded into a proximal collar 36 and captured in a distal collar 46.
• the proximal collar has a radial groove 40 in its distal portion and an increased diameter proximal portion 37 which carries a pair of electrical coupling pins 39, 41 which are electrically coupled to the rods 32, 34 respectively.
• the pins 39, 41 are spaced farther apart from each other than the rods 32, 34 so as to accommodate a standard cautery connector.
• the rods 32, 34 are covered with insulating high density polyethylene (HDPE) tubes along substantially their entire length between the proximal and distal collars 36, 46.
• HDPE high density polyethylene
• a plurality of spaced apart polypropylene cylinders 50 are molded about the rods between the proximal collar 36 and the distal collar 46. These cylinders stabilize the rods against helical twisting when the tube 16 is rotated. By being discontinuous, the cylinders 50 prevent the push rod assembly from warping.
• Figures 2, 2a, and 2b a first, non- insulated, electrically conductive scissor blade 26 according to the invention is shown with a curved distal portion 26a, a lower proximal tang 26b, and a mounting hole 26c therebetween.
• a connecting lug 26d extends orthogonally outward from the surface of the tang 26b in a first direction.
• the distal portion 26a includes an lower cutting edge 26e and an inner surface 26f (also called the shearing surface).
• a second, partially insulated, electrically conductive scissor blade 28 is configured similarly to the first scissor blade and has a curved distal portion 28a, an upper proximal tang 28b, and a mounting hole 28c therebetween.
• a connecting lug 28d extends orthogonally from the surface of the tang 28b in a second direction which is opposite to the first direction mentioned above.
• the distal portion 28a- includes an upper edge 28e and an inner surface or face 28f.
• the scissor blades 26, 28 may be made from a cobalt superaHoy such as cobalt chrome, or from stainless steel.
• the upper edge 28e and a portion of the inner surface 28f of the blade 28 is covered with an electrically non-conductive ceramic 29.
• the ceramic covering defines the cutting edge 29a which is spaced apart from the upper edge 28e of the blade 28 and also defines a portion 29b of the shearing or inner surface 28f of the blade 28.
• the ceramic covering 29 may be applied by any known means. It is presently preferred, however, that a lower portion of the inner surface 28f of the blade 28 be masked and that the ceramic 29 be sprayed onto the upper portion of the inner surface 28f and the upper edge 28e of the blade 28.
• the ceramic covering 29 may be provided as a relatively thin ceramic member which is bonded to the blade. It should be appreciated that while the surface 29b of the ceramic 29 is shown to lie in a different plane than the remainder of the shearing or inner surface 28f, the upper portion of the blade could be machined or otherwise formed so that upon application of the ceramic portion 29, the surfaces 29b and 28f lie in substantially the same plane.
• a scissor blade 128 is provided which is substantially the same as scissor blade 28 except for a tongue receiving groove 128g which extends along the inner surface 128f of the blade.
• An electrically non- conductive ceramic insert 129 is provided with a groove engaging tongue 129c and is inserted into the groove 128g of the blade 128.
• the insert 129 defines the cutting edge 129a of the blade 128 and also defines an upper portion 129b of the shearing surface 128f of the blade 128.
• the tongue receiving groove 128g may be provided by machining the blade 128 or may be molded into the blade 128 during casting of the blade.
• the ceramic insert 129 is cast or molded with an integral groove engaging tongue 129c which is kept in place in the groove 128g by an adhesive (not shown) , a friction fit, or any other desired mechanism.
• the upper portion of the blade could be machined or otherwise formed so that upon application of the ceramic portion 129, the surfaces 129b and 128f lie in substantially the same plane.
• a scissor blade 228 is provided which is substantially the same as the blade 28 and is partially coated with an electrically non-conductive ceramic 229.
• the only significant difference between this embodiment and the first embodiment is that in the first embodiment, only a relatively small portion of the inner surface of the blade was coated with ceramic insulator, while in this embodiment a relatively larger portion of the inner surface 228f (although not the entire face) of the blade is coated.
• the ceramic coating 229 is applied to define the cutting edge 229a of the blade 228 and to define part 229b of the shearing surface 228f of the blade.
• FIGs 4-6 Each of the embodiments of the invention operates in substantially the same manner which is illustrated in Figures 4-6.
• the scissor blades 26, 28 are shown in a first open position representing the start of a cutting procedure. It will be appreciated that the only point of contact P between the blades 26 and 28 is where their respective cutting edges 26e, 29a meet. However, because edge 29a is ceramic and substantially non- conductive, no short circuit can develop between the metal blades. As the blades are moved from the open position of Fig. 4 to the closed position of Figures 5 and 6, the point P moves distally along the cutting edges.
• the blades 26, 28 will flex at all points proximal of point P and remain spaced apart from each other at all points proximal of point P (as seen in Fig. 6) .
• the ceramic coating 29 (or ceramic insert 129, or coating 229) constitutes the cutting edge of one blade and prevents the non-insulated portion of the shearing surface 28f from contacting the shearing surface 26f of the other blade.
• the proximal portions 26b, 26d and 28b, 28d of the blades are insulated from each other by insulation in the clevis 30 ( Figure 1) .
• the current path between the blades is from the shearing surface 26f of the non- insulated blade 26 to the upper edge 28e of the insulated blade 28 behind the ceramic insulator 29b.
• the preferential current path is only completed when tissue is interposed between the blades. Therefore, the preferential current path between the blades moves distally with the point of contact P to cauterize tissue just before it is cut by the blades.
• the only difference between the operation of the embodiments relates to what happens to tissue which remains interposed between the shearing surfaces 26f, 28f proximal of the shearing point P. In the embodiments of Figs.
• interposed tissue will also be cauterized, while in the embodiment of Fig. 3d, the interposed tissue is less likely to be cauterized due to the arrangement of the insulating surface 229.
• the ceramic coating or insert prevents the blades from short circuiting the cautery current.

Applications Claiming Priority (3)

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• 1996
  • 1996-01-24 AU AU49014/96A patent/AU4901496A/en not_active Abandoned
  • 1996-01-24 CA CA002210726A patent/CA2210726A1/en not_active Abandoned
  • 1996-01-24 EP EP96905188A patent/EP0955920A1/en not_active Withdrawn
  • 1996-01-24 WO PCT/US1996/000874 patent/WO1996022740A1/en not_active Application Discontinuation
  • 1996-01-24 JP JP8522971A patent/JPH10512785A/ja active Pending

Non-Patent Citations (2)

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