Electromechanical polyp snare

[0001] 1. Field of the Invention

[0002] An electrosurgical device for use with an electrosurgical generator to remove polyps from the gastrointestinal tract.

[0003] 2. Description of the Prior Art

[0004] Electrosurgical generators used in cutting and coagulating have become common place. Such devices include electrosurgical polyp snares for use in removing polyps found in the gastrointestinal tract. Such surgical snares generally include an elongated flexible sheath connected to an operating hand piece. Extending through the sheath is an elongated flexible cable including an operating loop coupled to a movable portion of the operating hand piece so that the cable can be extended and retracted by a surgeon relative to the elongated flexible sheath to selectively open and close the operating loop as the surgeon manipulates the extended operating hand piece to protract or retract the cable. When the cable is in extended position the operating loop is fully employed outside the elongated flexible sheath and in its fully extended position. As the cable is retracted the operating loop is drawn into the elongated flexible sheath and closed around the polyp.

[0005] U.S. Pat. No. 4,256,113 and U.S. Pat. No. 4,294,254 show a surgical cannula including a sheath having a member movably disposed therein. With a surgical instrument operable by movement of the movable member relative to the sheath. The cannula further includes an operating assembly comprising a body or handle which slidably receives a slide for movement of the body including a pair of longitudinally spaced apart walls having the same general shape as the cross section of the body. The walls are provided with aligned apertures which rotatably receive a stem. The stem includes proximal and distal ends, and the proximal end of the movable member is fixedly attached to the distal end of the stem. The proximal end of the sheath is fixedly attached to the body portion of the handle. The stem is provided with a thumbwheel which is accessible through the side wall of the body being manipulatable to rotate the movable member in the sheath. The slide includes a rack and the body supports an additional thumbwheel having pinion gear teeth formed thereon, the pinion gear teeth engaging the rack. Manipulation of the second-mentioned thumbwheel causes the slide to move longitudinally within the body to move the movable member longitudinally within the sheath.

[0006] U.S. Pat. No. 6,346,106 relates to a surgical instrument including a body including a passageway, a snare electrode, a spool and an electrical connector. The snare electrode. A second portion of the snare electrode is extendable from passageway for forming a loop sized to be placed over tissue (e.g., portion(s) of the uterus and/or kidney(s), spleen, pancreas, gallbladder, remnant from the liver, and/or vascular aneurysm) to be removed from a patient. The spool is rotatably supported in a proximal part of the body. A first portion of the snare electrode is windable about the spool. A rotation of the spool in a winding direction causes retraction of the first portion of the snare electrode from a first port of the passageway thereby closing the loop to engage the tissue.

[0007] U.S. Pat. No. 4,293,752 shows a ribbon switch assembly including a tape switch strip.

[0008] U.S. Pat. No. 4,552,143 relates to a removable switch electrocautery instrument, comprising a releasably mounting switch means with a conductive member adapted to come into contact with living tissue and a handle member. Means are provided on the switch means to make an electrical connection with the conductive member adapted to come into contact with the living tissue. Electrical connection between the switch means may be made through one of the springably releasable attachments or a separate connector element.

[0009] U.S. Pat. No. 5,304,763 shows an electrosurgical hand piece of different-sized electrodes having hollow shanks and means for supplying suction adjacent the electrode tip for simultaneous removal of liquids or gasses. The hand piece can be fitted with a removable finger switch activator which can also be attached to other objects for the surgeon's convenience. Means for controlling the suction pressure at the electrode tip are also provided.

[0010] U.S. Pat. No. 5,433,702 shows a hand piece operatively coupled to a phacoemulsification machine to supply the hand piece with irrigation fluid, aspiration suction and ultrasonic energy. The application of irrigation fluid and aspiration suction to the hand piece are preferably controlled with a foot pedal which is operatively coupled to the phacoemulsification machine. The application of ultrasonic energy to the hand piece is controlled by a button, slide tab, knob or the like which is preferably detachably mounted to the main body of the hand piece so that the application of ultrasonic energy can be manually controlled by the surgeon.

[0011] Many of the prior art surgical snares are difficult to manipulate with precision at the point of application. In addition, control of the various operating modes through hand and foot switches is unnecessarily awkward.

[0012] The present invention relates to an electrosurgical device for use with an electrosurgical generator to remove polyps from the gastrointestinal tract of a patient.

[0013] The electrosurgical device comprises a hand piece, a snare positioning assembly and polyp snare.

[0014] The hand piece comprises a body or housing and a snare support member attached thereto.

[0015] The polyp snare extending from the snare positioning assembly through the snare support comprises an electrically nonconductive sheath having an electrically conductive snare wire terminating in a polyp snare or loop slidably disposed therein.

[0016] The snare positioning assembly comprises a drive motor operatively coupled to a positioning slide to extend and retract the polyp snare or loop within the gastrointestinal tract of patient for removal of a polyp therefrom.

[0017] The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

[0026] Similar reference characters refer to similar parts throughout the several views of the drawings.

[0027] As shown in FIG. 1, the present invention relates to an electrosurgical device generally indicated as 10 for use with an electrosurgical generator (not shown) to remove polyps from the gastrointestinal tract of a patient.

[0028] The electrosurgical device 10 comprises a hand piece, a snare positioning assembly, a remote or auxiliary switch assembly, a snare support and polyp snare generally indicated as 12, 14, 16, 18 and 20 respectively.

[0029] The hand piece 12 comprises a body or housing generally indicated as 22 having an operator handle generally indicated as 24 and a snare support member generally indicated as 26 attached to the lower portion and the front portion thereof respectively. A conventional switch arrangement generally indicated as 28 that can alternately be used to control operation of the electrosurgical device 10 is mounted on the top of the body or housing 22. The switch arrangement 28 is coupled or connected to the electrosurgical generator (not shown) by an electrosurgical generator cable 30.

[0030] The snare positioning assembly 14 and the snare support 18 are attached to or mounted on the snare support member 26 respectively.

[0031] As shown in FIG. 1, the polyp snare 20 extending from the snare positioning assembly 14 through the snare support 18 as described more fully herewith comprises an electrically nonconductive sheath 32 having an electrically conductive snare wire 34 terminating in a polyp snare or loop 36 slidably disposed therein.

[0032] As shown in FIG. 1, the snare support 18 comprises a proximal hollow base member 38 including a snare aperture or opening 40 formed through a side wall 42 thereof and a distal flexible elongated snare guide 44 having a snare channel 46 formed therethrough such that the electrosurgical nonconductive sheath 32 and the electrically conductive snare wire 34 extend from the forward or distal end portion 48 of the snare positioning assembly 14 through the snare aperture or opening 40 and the snare channel 46 through the forward distal end portion 50 of the distal flexible elongated snare guide 44.

[0033] As shown in FIGS. 1 through 4, the remote or auxiliary switch assembly 16 comprises a switch pad 52 to operatively support an electrosurgical generator control switch 54 to selectively activate the electrosurgical generator (not shown), a snare positioning switch 56 to selectively control operation of the snare positioning assembly 14 to extend and retract the electrically conductive snare wire 34 and the electrically conductive polyp loop 36, and a polyp cutting switch 58 to selectively feed current through the electrically conductive snare wire 34 and electrically conductive polyp loop 36 when disposed in surrounding relationship relative to a polyp to be removed from the gastrointestinal tract of a patient. The switches 54, 56 and 58 are coupled to the electrosurgical generator (not shown) by a corresponding conductor disposed with a conductor cable 60.

[0034] As best shown in FIGS. 2 and 3, the snare positioning assembly 14 comprises a reversible drive motor 62 operatively coupled to a positioning slide generally indicated as 64 by an intermediate drive mechanism generally indicated as 66. The positioning slide 64 comprises a slide rack 68 including a plurality of teeth 70 formed on the upper surface of the distal portion thereof. The proximate hollow base member 38 comprises a snare support generally indicated as 72 having a snare channel 74 formed therethrough to slidingly receive a portion of the polyp snare 20 when the polyp snare 20 is directed into the snare aperture or opening 40. The intermediate drive mechanism 66 comprises a first drive section generally indicated as 76 and a second drive section generally indicated as 78 disposed to operatively engage each other to extend and retract the positioning slide 64 and the polyp snare 20 through the snare channel 46 to position the polyp snare or loop 36 within the gastrointestinal tract of patient for removal of a polyp therefrom.

[0035] Specifically, the first drive section 76 comprises a drive gear 80 coupled to the reversible drive motor 62 by a drive shaft 82; while, the second drive section 78 comprises a first drive gear 84 in operatively engagement with the drive gear 80 and a second drive gear 86 coupled thereto by a connecting shaft 88 in operative engagement with the teeth 70 of the slide rack 68 to move the positioning slide 64 and the snare support 72 in response to operation of the reversible drive motor 62 to advance and withdraw the polyp snare 20 through the snare aperture or opening 40 and the snare channel 46.

[0036] In use, the switch pad 52 of the remote or auxiliary switch assembly 16 may be attached to the hand piece 12 with a self-adhesive strip 90 or attached to a cable or other portion of the electrosurgical device 10, electrosurgical generator (not shown) or accessory by a clip or device 92 such as a loop or clamping element or fingers as shown in FIG. 2.

[0037] The electrosurgical generator control switch 54 and the polyp cutting switch 58 can each comprise a two position on-off contact switch; while the snare positioning switch 56 may comprise a three position contact switch to control the operating direction of the reversible motor 62 to control the direction of travel of the polyp snare 20.

[0038] In operation, as shown in FIG. 1, the switch assembly 16 mounts on the electrosurgical hand piece handle 10 or the other portion of the electrosurgical device 10. It can be easily positioned to any location convenient to the surgeon where he or she can easily manipulate the switches 54, 56 and 58 with one or two fingers to control the application of electrosurgical energy to the polyp snare or loop 36 electrode.

[0039] The electrosurgical generator (not shown) is controlled or activated by depressing the electrosurgical generator control switch 54.

[0040] The electrosurgical device 10 is held by the surgeon to position the polyp snare 20 by inserting the distal end portion of the electrically nonconductive sheath 32 and electrically conductive snare wire 34 with the polyp snare or loop 36 extending therefrom into the gastrointestinal tract of the patient. The polyp snare or loop 36 is manipulated relative to the polyp by the snare position switch 56. Once the polyp snare or loop 36 is positioned around the polyp, the polyp cutting switch 58 is turned on to feed cutting power or current from the electrosurgical generator (not shown) through the electrically conductive snare wire 34 to the polyp snare or loop 36 to cut the polyp from the intestinal wall. Power to the electrically conductive snare wire 34 and the polyp snare or loop 36 is turned off by depressing the polyp cutting switch 38. The polyp snare 20 is then withdrawn from the gastrointestinal tract by activating the reversible drive motor 62 by depressing the snare positioning switch 56.

[0041] FIGS. 5 through 7 show an alternate embodiment of the snare positioning assembly 14. Corresponding structural elements are numbered as in FIGS. 1 through 3. The snare positioning assembly 14 comprises a positioning slide generally indicated as 164 comprising a slide 166 including a push or finger tab 168 formed on the side thereof and a bias stop or shoulder 170 and a hollow snare support generally indicated as 172 having a snare channel 174 formed therethrough to slidingly receive a portion of the polyp snare 20 therein to direct the polyp snare 20 into the snare aperture or opening 40 and a bias 176 such as a spring.

[0042] The bias 176 is disposed in the snare channel 174 to engage the bias stop 170 and a second bias stop 178 formed in the distal end portion of the snare channel 174 to engage opposite ends of the bias 176 to normally maintain the slide 166 in the first or retracted position as shown in FIG. 6.

[0043] The slide 166 and the polyp snare 20 are extended to position the polyp snare or loop 36 within the gastrointestinal tract of patient for removal of a polyp therefrom by moving the push or finger tab 168.

[0044] Once the polyp snare or loop 36 is properly positioned around the polyp and power applied to cut or remove the polyp, the push or finger tab 168 is released. The bias 176 retracts the slide 166 withdrawing the polyp snare or loop 36 and polyp from the patient. Power or current is supplied to the polyp loop 36 fed through connector 180.

[0045] It will thus be seen that the objects set forth above, among those made apparent from the preceding description are efficiently attained and since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

[0046] It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.