Device for converting a mechanical cutting device to an electrosurgical cutting device

• US 6,193,715 B1
• Filed: 03/19/1999
• Issued: 02/27/2001
• Est. Priority Date: 03/19/1999
• Status: Expired due to Term

• Current Assignee: PCN Corp. (CMIC Holdings Co., Ltd.)
• Original Assignee: Medical Scientific Incorporated
• Inventors: Lemire, Kevin P., Nardella, Paul C. Sr., Allaire, Kevin M., Wrublewski, Thomas A.
• Primary Examiner(s): Dvorak, Linda C. M.
• Assistant Examiner(s): Ruddy, David M.
• Application Number:
  US09/272,272
• Time in Patent Office: 711 Days
• Field of Search: 606/160, 606/171, 606/179, 606/180, 606/181, 606/170, 606/45-50, 606/41, 606/42, 604/21, 604/22
• US Class Current: 606/45
• CPC Class Codes: A61B 17/32 Surgical cutting instruments A61B18/042 takes precedence; suture cutters A61B17/0467; instruments for ligaturing or cutting A61B17/128; instruments for rupturing the amniotic membrane A61B17/4208; specially adapted knives for eye surgery A61F9/0133
• CPC Class Codes: A61B 18/1402 Probes for open surgery
• CPC Class Codes: A61B 18/148 having a short, rigid shaft for accessing the inner body transcutaneously, e.g. for neurosurgery or arthroscopy
• CPC Class Codes: A61B 18/1482 having a long rigid shaft for accessing the inner body transcutaneously in minimal invasive surgery, e.g. laparoscopy
• CPC Class Codes: A61B 18/16 Indifferent or passive electrodes for grounding
• CPC Class Codes: A61B 2017/00296 mounted on an endoscope

Abstract

An adapter unit for a mechanical tissue cutting implement such as a shaver, morcellator or the like includes a mounting block from which an electrically insulating sheath extends. The sheath fits over the cannula or shaft of the cutting implement, and is secured in alignment and attached so that the cutting tip, for example, the tool and its window in the cannula tip, are exposed through the sheath. A conductor, which may be a conductive layer, extends along the length of the sheath and is exposed to form a distal electrode at the tip in close proximity to the opening, constituting one electrode of a bipolar electrode arrangement at the exposed tool. The other electrode is provided by electrical connection to the implement itself, so that a high current density path is formed through tissue in the cutting region. Preferably both output connections of an electrosurgical generator are coupled through a matching transformer to the mounting block by a plug, socket, cable or fixed cord arrangement, and the mounting block may, for example, be formed of plastic, preferably having an alignment feature such as a notch to fasten to the implement so that the sheath opening aligns with the cutter. Electrical connection to the implement may be effected via a conductive bushing, fastening bolt or the like which contacts one of the supply leads through a wire, spring or other conductive path. The adapter may also provide a sheath opening and distal electrode about a non-apertured region of the cannula, for example on the rear surface of the cannula opposed to the cutting tool aperture, to form a hemostasis element that may be rotated into position to coagulate bleeding. In this case the bipolar electrode geometry may be configured for high energy density delivery that does not vary with tool rotation. The adapter may also convert a monopolar device to bipolar operation, providing a single additional electrode positioned by the sheath at the cutting aperture.

Claims

1. An adapter device for a mechanical cutting device, the adapter device comprising:

a mounting block adapted to couple the adapter device to the mechanical cutting device;

an electrical connecting element coupled to said mounting block;

a sheath carried by said mounting block and coupled to said connecting element, said connecting element providing a conductive pathway between said sheath and the mechanical cutting device, said sheath having an inner surface which defines a passageway adapted to accept the mechanical cutting device, and at least a portion of said sheath which corresponds to the inner surface of said sheath including a non-conductive substrate and a first conductive layer disposed over the substrate with an insulating layer disposed over the conductive layer, wherein said sheath has a proximal portion having an open end and a distal portion having an aperture positioned by the sheath at a cutting tool of the mechanical cutting device, the aperture being defined by a band of the non-conductive substrate closely separating a conductive portion of the mechanical cutting device from an exposed portion of the conductive layer such that upon coupling of the sheath to the mechanical cutting device and powering the mechanical cutting device, the conductive layer provides an electrical return at the distal portion of the sheath to the connecting element such that the adapter device converts the mechanical cutting device for bipolar electrosurgical operation at the aperture.

2. The adapter device of claim 1 wherein said connecting element comprises first and second electrodes with a first one of said first and second electrodes coupled to said mounting block and a second one of said first and second electrodes coupled to the conductive layer of said sheath.

3. The adapter device of claim 2 wherein the aperture defines a cutting area and the conductive layer is exposed about the aperture proximate the cutting area.

4. The adapter device of claim 1, wherein said sheath is a flexible sheath assembly.

5. The adapter device of claim 1, wherein the device is configured for a mechanical cutting instrument having a removable and replaceable cannula, and said mounting block and sheath are permanently affixed to the cannula to form an electrosurgical replacement cutter tool assembly.

6. The adapter device of claim 1, wherein the sheath further comprises a second aperture positioned to expose a region of the mechanical cutting device and form a bipolar electrode arrangement for contacting and hemostatic sealing of cut tissue.

7. A method of converting a mechanical cutting device having a cutting blade, such method comprising the steps of:

providing a sheath with an open proximal end and a distal end having an apertured cutting area, the sheath including a non-conductive substrate, a conductive layer and an insulating layer;

placing a plurality of conductive elements to provide a conductive pathway to the sheath and to the cutting device;

coupling the cutting device to the sheath by inserting the cutting device through the open proximal end such that the cutting device is aligned at the apertured cutting area and is separated from an exposed portion of the conductive layer by a band of said non-conductive substrate at the cutting area;

such that by connecting an electrosurgical generator to at least one of the plurality of conductive elements and activating the electrosurgical generator, the cutting device operates as a bipolar electrosurgical instrument.

8. The method of claim 7, wherein the first conductive element and the second conductive element are each metal pin connectors.

9. The method of claim 7, wherein the first conductive element and the second conductive element are formed by a cord assembly.

10. An adapter device for converting a mechanical or monopolar cutting instrument, wherein the mechanical or monopolar cutting instrument includes a handle, a cannula and a cutting blade that moves within a cutting aperture of the cannula to effect tissue cutting, said adapter device comprising

a mounting block

an insulative sheath assembly carried by and extending from the mounting block and carrying an enclosed conductor extending along the length of the sheath to a window and with an exposed conductive portion of said conductor at said window, and

an electrosurgical connector carried by said mounting block for connecting an electrosurgical energy source to said enclosed conductor and to said mechanical or monopolar cutting instrument,

said mounting block and sheath being configured for insertion of the cannula therein such that said exposed conductive portion is positioned and aligned adjacent the cutting aperture and is spaced from a conductive portion of the cutting instrument by a band of insulation to effectively provide bipolar electrosurgical electrodes at the window, thereby converting the mechanical or monopolar cutting instrument to a bipolar device.

11. An adapter assembly configured to attach to a monopolar or mechanical cutting device, the adapter assembly comprising:

a generally tubular non-conductive substrate having an inner surface and an outer surface;

a conductor disposed over the outer surface of the substrate;

an insulating layer disposed over the conductor

wherein a distal portion of the substrate includes an opening formed therein in a side of the tubular substrate which defines a cutting area, at least a partial perimeter of the cutting area being defined by a band of the non-conductive substrate closely separating an exposed region of the conductor from the opening, a proximal portion of the substrate having an open end adapted for insertion of the monopolar or mechanical cutting device therein, and having plurality of conductive elements for providing a conductive pathway between the conductor and the cutting device; and

such that when the substrate is fitted over the cutting device and an electrosurgical generator is connected to at least one of the plurality of conductive elements, the conductor provides an electrical return at the distal portion of the sheath to an active electrode such that the device is converted to operate as a bipolar device.

12. The adapter assembly of claim 11, wherein the plurality of conductive elements includes:

a first conductive element adapted for connection to the conductor and to the electrosurgical generator; and

a second conductive element adapted for connection to the cutting device and to the electrosurgical generator.

13. The adapter assembly of claim 12, further comprising and alignment feature adapted to align the cutting device within the sheath.

14. The adapter assembly of claim 11, wherein upon coupling of the cutting device to the adapter assembly, a blade within the cutting device is capable of at least one of longitudinal and rotational movement within the sheath.

15. The adapter assembly of claim 11, wherein upon coupling of the cutting device to the adapter assembly, the cutting blade of the cutting device is disposed at the opening of the distal portion of the adapter assembly.

16. The adapter assembly of claim 15, wherein the blade is separated from the conductive layer by no more than about two millimeters.

17. The adapter assembly of claim 11, wherein the opening extends for between about five to about fifteen millimeters of a longitudinal length of the sheath.

18. The adapter assembly of claim 11, wherein the distal portion of the adapter assembly has an end distal to the opening.

19. The adapter assembly of claim 13, wherein the distal end is substantially arcuate.

20. The adapter assembly of claim 13, wherein the distal end is substantially straight.

21. The adapter assembly of claim 11, wherein the exposed conductor is disposed distally and proximally of the opening at the distal portion of the substrate.

22. The adapter assembly of claim 11, wherein upon coupling of the cutting device to the adapter assembly, the cutting device is insulated from the intermediate area and proximal portion of the adapter assembly by insulating material.

23. The adapter assembly of claim 20, wherein the conductor is applied on the non-conductive substrate and the insulating layer is applied on the conductor.