Electrosurgical snare

• US 6,773,432 B1
• Filed: 04/05/2002
• Issued: 08/10/2004
• Est. Priority Date: 10/14/1999
• Status: Expired due to Fees

• Current Assignee: Applied Medical Resources Corporation (Applied Medical Corporation)
• Original Assignee: Applied Medical Resources Corporation (Applied Medical Corporation)
• Inventors: Landman, Jaime, Clayman, Ralph V., Collyer, William C.
• Primary Examiner(s): Gibson, Roy D.
• Assistant Examiner(s): ROANE, AARON F
• Application Number:
  US10/110,159
• Time in Patent Office: 858 Days
• Field of Search: 606/45-49, 606/113
• US Class Current: 606/41
• CPC Class Codes: A61B 17/32056 Surgical snare instruments for removing or smashing calculi A61B2017/2212; tonsillotomes A61B17/26
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 2018/00083 low, i.e. electrically insulating
• CPC Class Codes: A61B 2018/1407 Loop
• CPC Class Codes: A61B 2018/141 Snare

Abstract

An electrosurgical instrument includes a handle with a hollow elongate configuration and an electrosurgical assembly having ends disposed within the hollow handle and forming a continuous loop moveable by operation of the handle between an enlarged state and a contracted state. An electrosurgical element included in the assembly has an outer surface and axis and a lumen extending along the axis. Transverse portions of the element define a plurality of slots extending transverse to the axis and providing fluid communication between the lumen and the outer surface of the element. The element includes an insulated backbone and a plurality of ribs disposed to extend in space relationship to each other transverse to the backbone. A method of manufacture includes the step of creating slots in the element to define the ribs in the backbone.

Claims

1. An electrosurgical instrument adapted for use with an electrosurgical generator to sever an element of tissue from a patient at an operative site, comprising:

a handle having an elongate configuration and extending between a proximal end and a distal end;

an electrosurgical assembly extending from the distal end of the handle and forming a continuous loop disposed generally in a loop plane, the electrosurgical assembly being free of any obstruction on at least one side of the loop plane to facilitate placement of the continuous loop over the element of tissue to be severed;

the electrosurgical assembly being moveable by operation of the handle between an enlarged state wherein the continuous loop has a first size facilitating engagement of the element of tissue and a contracted state wherein the continuous loop has a second size smaller than the first size facilitating severance of the element of tissue from the patient;

an electrosurgical element bent back on itself to form the continuous loop in the assembly, the electrosurgical element having an outer surface, an axis, and a lumen extending along the axis;

portions of the electrosurgical element defining a plurality of slots providing fluid communication between the lumen and the outer surface to facilitate passage of a fluid between the lumen of the electrosurgical element and the operative site.

2. The electrosurgical instrument recited in claim 1, wherein;

the electrosurgical element has the configuration of a cylinder with a radius; and

the slots extend into the electrosurgical element a particular distance not less than the radius of cylinder.

3. The electrosurgical instrument recited in claim 1, further comprising:

longitudinal portions of the electrosurgical element defining a backbone extending along the axis of the electrosurgical element and facing outwardly of the loop; and

insulation disposed on the outer surface of the electrosurgical element along the backbone.

4. The electrosurgical instrument recited in claim 1, wherein each of the slots is disposed generally in a slot plane transverse to the axis of the electrosurgical element.

5. The electrosurgical instrument recited in claim 1, further comprising:

a rigid arm included in the electrosurgical assembly and extending from the distal end of the handle to engage the electrosurgical element at a location spaced from the distal end of the handle.

6. The electrosurgical instrument recited in claim 5, further comprising:

longitudinal portions of the electrosurgical element defining a backbone facing away from the arm of the electrosurgical assembly.

7. The electrosurgical instrument recited in claim 1, wherein the handle includes a hollow sleeve and the electrosurgical assembly is sized and configured to be moved into the sleeve toward the contracted state and to be moved out of the sleeve toward the enlarged state.

8. The electrosurgical instrument recited in claim 1, wherein the electrosurgical element is accessible at the proximal end of the handle to permit the injection of a fluid into the lumen, and through the lumen and the slots to the outer surface of the electrosurgical element.

9. The electrosurgical instrument recited in claim 1, wherein at least one of the slots has a first side defined in a first plane and a second side defined in a second plane generally parallel to the first plane.

10. The electrosurgical instrument recited in claim 1, wherein the electrosurgical element is a first electrosurgical element and the instrument further comprises a second electrosurgical element opposing the first electrosurgical element.

11. The electrosurgical instrument recited in claim 10, wherein the second electrosurgical element is coupled to the first electrosurgical element by an insulator.

12. An electrosurgical instrument adapted for use with an electrosurgical generator to sever tissue from a patient, comprising:

a handle having an elongate configuration and extending between a proximal end and a distal end;

an electrosurgical assembly extending from the distal end of the handle and being moveable by operation of the handle between an enlarged state and a contracted state;

an electrosurgical element included in the electrosurgical assembly and having an axis, the element being bent back on itself to form a loop;

a backbone disposed to extend longitudinal along the axis, the backbone facing generally outwardly of the loop;

a plurality of ribs included in the electrosurgical element and disposed to extend in a spaced relationship to each other transverse to the backbone, the ribs facing generally inwardly of the loop; and

insulation disposed along the backbone but not along the ribs to inhibit the cutting of tissue along the backbone and to facilitate the cutting of tissue along the ribs.

13. The electrosurgical instrument recited in claim 12 wherein the electrosurgical element in cross-section has the general shape of a circle.

14. The electrosurgical instrument recited in claim 13 wherein the electrosurgical instrument is hollow.

15. (Original) The electrosurgical element recited in claim 12 wherein at least two of the ribs are generally parallel to each other and generally perpendicular to the backbone.

16. A method of manufacturing an electrosurgical instrument adapted to produce an electrosurgical effect on body tissue, comprising the steps of:

providing a handle having a longitudinal channel;

providing an electrosurgical assembly having a first end and a second end defining a generally closed loop, at least one of the first end and the second end being moveable within the longitudinal channel of the handle to vary the size of the loop;

creating slots in the electrosurgical element to define a plurality of ribs facing inwardly of the loop, and a backbone facing outwardly of the loop;

placing insulation over at least a portion of the backbone to inhibit the electrosurgical effect outwardly of the loop; and

during the placing step, ensuring that the insulation does not extend over at least a portion of the ribs to facilitate the electrosurgical effect inwardly of the loop.

17. The method recited in claim 16, further comprising the step of:

moving the electrosurgical assembly within the channel to enlarge the loop in order to facilitate placement of the loop around the body tissue.

18. The method recited in claim 17, further comprising the step of:

drawing the electrosurgical assembly into the channel to reduce the size of the loop around the body tissue and to facilitate the electrosurgical effect on the body tissue.

19. The method recited in claim 16 further comprising the step of:

passing a liquid through the slots to facilitate the electrosurgical effect between the electrosurgical element and the body tissue.