Accurate cutting about and into tissue volumes with electrosurgically deployed electrodes

• US 6,514,248 B1
• Filed: 10/15/1999
• Issued: 02/04/2003
• Est. Priority Date: 10/15/1999
• Status: Expired due to Fees

• Current Assignee: Intact Medical Corporation (Medtronic Plc)
• Original Assignee: Neothermia Corporation (Medtronic Plc)
• Inventors: Eggers, Philip E., Eggers, Eric A., Eggers, Andrew R.
• Primary Examiner(s): ROLLINS, ROSILAND STACIE
• Application Number:
  US09/418,923
• Time in Patent Office: 1,208 Days
• Field of Search: 606/41, 606/45, 606/46, 606/47, 606/48, 606/49
• US Class Current: 606/41
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00973 pedal-operated
• CPC Class Codes: A61B 2018/00011 with fluids
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/1286 having a specific transformer
• CPC Class Codes: A61B 2018/1475 Electrodes retractable in or deployable from a housing
• CPC Class Codes: A61B 2218/002 Irrigation

Abstract

Method, system and apparatus for carrying out accurate electrosurgical cutting. A thin resilient electrode is utilized at the forward end region of an instrument which is deployable from a longitudinally disposed slot positioned rearwardly of the tip of the instrument. Lateral sides of the slot extend between a forward location adjacent the tip and a rearward location. The electrode is deployed by urging it forwardly in compression to form an arch profile supported by the abutting slot sides adjacent the forward and rearward locations. Electrosurgically excitable with a cutting output, the electrode may carry out a cutting action both during its deployment and retraction into the noted slot. This permits a pivoting maneuver effective for circumscribing a volume of targeted tissue.

Claims

1. A method for carrying out the circumscriptive isolation of targeted tissue exhibiting a given peripheral extent and surmounted by viable tissue, comprising the steps of:

(a) providing an electrosurgical generator assembly having an electrosurgical return, controllable to generate a first output for carrying out electrosurgical cutting of tissue;

(b) providing an instrument electrically coupled with said electrosurgical generator assembly, having a support member extending between a tip and a base region, having a forward end region extending along a longitudinal axis movable with respect to said targeted tissue, and having an electrode at said forward end region actuable for deployment from a retracted orientation to deployed orientations and from said deployed orientations toward a retracted orientation;

(c) positioning said instrument forward end region within said viable tissue in adjacency with said targeted tissue peripheral extent with said electrode in a said retracted orientation;

actuating said instrument to deploy said electrode in adjacency with said targeted tissue peripheral extent and thence along and in adjacency with said targeted tissue peripheral extent and retracting said electrode toward a retracted orientation to describe a tissue isolating locus of movement within said viable tissue about said targeted tissue peripheral extent; and

(e) simultaneously with said step (d) controlling said electrosurgical generator assembly to apply said first output to said electrode in electrical association with said electrosurgical return to establish an electrosurgical cut along said locus of movement of said electrode effective to provide a substantial vascular isolation of said targeted tissue from said viable tissue.

2. The method of claim 1 in which:

said step (a) provides a said electrosurgical generator assembly as being controllable to generate a second output for carrying out the coagulation of tissue;

including the steps of;

(f) reiterating said step (d); and

(g) simultaneously with said step (f) controlling said electrosurgical generator assembly to apply said second output to said electrode in electrical association with said return to provide electrosurgical coagulation along said electrosurgical cut derived in said step (e).

3. The method of claim 2 in which:

said step (b) provides said instrument as having a said electrode which is thin, resilient and forming an arch shaped profile extending outwardly from two spaced apart locations when deployed from a said retracted orientation; and

said step (d) comprises the actuating steps of;

(d1) urging said electrode outwardly to effect formation of said arch shaped profile and the location thereof adjacent one side of said targeted tissue peripheral extent,

(d2) thence said actuation is further carried out by effecting pivotal rotation of said electrode along a said locus circumscribing a continuous portion of said targeted tissue peripheral extent.

4. The method of claim 1 in which:

said step (a) provides a said electrosurgical generator assembly as being controllable to generate a second output for carrying out the coagulation of tissue and is further controllable to provide a blend output alternately generating said first output and said second output in accordance with a predetermined duty cycle; and

said step (e) is carried out by controlling said electrosurgical generator assembly to apply said blend output to said electrode in electrical association with electrosurgical return to establish a said electrosurgical cut with adjacent coagulated cut surfaces.

5. The method of claim 1 in which:

said step (b) provides said instrument with a fluid delivery channel extending from a fluid input in the vicinity of said base region to a fluid output at said forward end region and providing a supply of barrier fluid effective to retard the rate of neovascularization in fluid transfer communication with said fluid input; and

including the step of;

(f) expressing said barrier fluid from said fluid output for dispersion within said electrosurgical cut.

6. The method of claim 1 in which:

said step (b) provides said instrument as having a said electrode which is thin and resilient, having a distal end connected with said support member at a connection location adjacent said tip and extending therefrom an arch defining distance; and

said step (d) comprises the actuating steps of;

(d1) urging said electrode forwardly toward said tip in compression to effect its deployment from an initial angular orientation of said forward end region as an outward movement in adjacency with one side of said peripheral extent of said targeted tissue, said outward movement being to an extent curving said electrode into an outwardly depending arch formation having an arch apex of circumscription height extensible over said targeted tissue when said forward end region is pivoted.

(d2) pivoting said forward end region to a second angular position to, in turn, pivot said electrode over said targeted tissue peripheral extent to a next side thereof opposite said one side,

(d3) effecting retraction of said electrode by urging it rearwardly toward said base region to effect its retracting movement to a retracted orientation below said targeted tissue peripheral extent to effect said electrosurgical cut along three contiguous regions of said targeted tissue peripheral extent.

7. A method for the treatment of an atrial flutter reentry circuit at a heart wall comprising the steps of:

(a) providing a control system including an electrosurgical generator actuable to derive an electrosurgical cutting output and a mapping system controllable for response to an electrical parameter to locate the path of said reentry circuit;

(b) providing an intravascular catheter electrically coupled with said control system, extending from a base region to a tip, having a forward end region adjacent said tip including a deployment slot longitudinally disposed between a forward location adjacent said tip and a rearward location, having a thin, resilient electrode at said forward end region having a distal end fixed to said catheter, extending within said deployment slot during insertion and removal modes and extending within said catheter beyond said rearward location an arch defining distance;

(c) percutaneously introducing said catheter into the vascular system to locate said forward end region within the heart;

(d) controlling said mapping system to locate the current flow position of said reentry circuit with respect to a heart wall;

(e) positioning said deployment slot adjacent said heart wall at said current flow position in a longitudinal orientation effective for deriving a current interrupting impedance;

(f) urging said electrode forwardly toward said tip in compression to effect its deployment outwardly from said deployment slot into an arch formation having an arch apex determined by said arch defining distance;

(g) simultaneously with said step (f), actuating said electrosurgical generator to apply said cutting output to said electrode; and

(h) retracting said electrode into said deployment slot by urging it rearwardly.

8. The method of claim 7 in which said steps (d) through (h) are reiterated until said re-entry circuit is beneficially interrupted by the impedance of necrotic tissue formed by said electrode.

9. The method of claim 7 in which:

said step (b) includes the provision of at least one surface electrode at said forward end region aligned with said deployment slot and electrically coupled with said mapping system; and

said step (e) is carried out by controlling said mapping system to determine when said surface electrode is in electrically discernable contact with said heart wall.

10. The method of claim 7 in which said step (e) is carried out by positioning said deployment slot wherein its longitudinal extent is generally transversely oriented with respect to said path of said reentry circuit.

11. A method for carrying out the necrosis of a volume of targeted tissue exhibiting a given peripheral extent and surmounted by viable tissue, comprising the steps of:

(a) providing an electrosurgical generator assembly having an electrosurgical return, controllable to generate a first output for carrying out electrosurgical cutting of tissue;

(b) providing an instrument electrically coupled with said electrosurgical generator assembly, having a support member extending between a tip and a base region, having a forward end region extending along a longitudinal axis movable with respect to said targeted tissue, and having an electrode at said forward end region with a distal end fixed to said support member actuable for deployment from a retracted orientation to deployed orientations and from said deployed orientations toward a retracted orientation;

said instrument being provided as having a said electrode which is thin and resilient, having a distal end connected with said support member at a connection location adjacent said tip and extending therefrom an arch defining distance;

(c) positioning said instrument forward end region within said viable tissue in adjacency with said targeted tissue peripheral extent with said electrode in a said retracted orientation;

(d) actuating said instrument to deploy said electrode in adjacency with said targeted tissue peripheral extent and thence along and in adjacency with said targeted tissue peripheral extent by pivoting said forward end region and retracting said electrode toward said retracted orientation to describe a locus of movement about said targeted tissue peripheral extent;

said step (d) comprising the actuating steps of;

(d1) urging said electrode forwardly toward said tip in compression to effect its deployment from an initial angular orientation of said forward end region as an outward movement in adjacency with one side of said peripheral extent of said targeted tissue, said outward movement being to an extent curving said electrode into an outwardly depending arch formation having an arch apex of circumscription height extensible over said targeted tissue when said forward end region is pivoted,

(d2) pivoting said forward end region to a second angular position to, in turn, pivot said electrode over said targeted tissue peripheral extent to a next side thereof opposite said one side,

(d3) effecting retraction of said electrode by urging it rearwardly toward said base region to effect its retracting movement to a retracted orientation below said targeted tissue peripheral extent to effect said electrosurgical cut along three contiguous regions of said targeted tissue peripheral extent,

(d4) pivoting said forward end region between said second and initial angular orientations to, in turn, pivot said electrode, said locus of movement circumscribing said targeted tissue along four contiguous regions; and

(e) simultaneously with said step (d) controlling said electrosurgical generator assembly to apply said first output to said electrode in electrical association with said electrosurgical return to establish an electrosurgical cut along said locus of movement of said electrode effective to provide a substantial vascular isolation of said targeted tissue from said viable tissue.

12. The method of claim 11 in which:

said step (d) includes the step of;

(d4) subsequent to said step (d3), pivoting said forward end region from said second to said initial angular orientation to, in turn, pivot said electrode, said locus of movement circumscribing said targeted tissue along four contiguous regions; and

including the step (f2) of expressing said barrier fluid from said fluid output subsequent to said step (d4).

14. The method of claim 13 or 12 in which said step (b) provides said instrument as having a said electrode with an interior fluid transfer cavity having a cavity fluid input in fluid transfer communication with said fluid delivery channel and said fluid output is formed within said electrode in fluid transfer communication with said cavity.

13. A method for carrying out the necrosis of a volume of targeted tissue exhibiting a given peripheral extent and surmounted by viable tissue, comprising the steps of:

(a) providing an electrosurgical generator assembly having an electrosurgical return, controllable to generate a first output for carrying out electrosurgical cutting of tissue;

(b) providing an instrument electrically coupled with said electrosurgical generator assembly, having a support member extending between a tip and a base region, having a forward end region extending along a longitudinal axis movable with respect to said targeted tissue, and having an electrode at said forward end region with a distal end fixed to said support member actuable for deployment from a retracted orientation to deployed orientations and from said deployed orientations toward a retracted orientation,

said instrument being provided as having a said electrode which is thin and resilient, having a distal end connected with said support member at a connection location adjacent said tip and extending therefrom an arch defining distance;

said instrument being further provided with a fluid delivery channel extending from a fluid input in the vicinity of said base region to a fluid output at said forward end region and providing a supply of barrier fluid effective to retard the rate of neovascularization in fluid transfer communication with said fluid input;

(c) positioning said instrument forward end region within said viable tissue in adjacency with said targeted tissue peripheral extent with said electrode in a said retracted orientation;

(d) actuating said instrument to deploy said electrode in adjacency with said targeted tissue peripheral extent and thence along and in adjacency with said targeted tissue peripheral extent by pivoting said forward end region and retracting said electrode toward said retracted orientation to describe a locus of movement about said targeted tissue peripheral extent;

said step (d) comprising the actuating steps of;

(d1) urging said electrode forwardly toward said tip in compression to effect its deployment from an initial angular orientation of said forward end region as an outward movement in adjacency with one side of said peripheral extent of said targeted tissue, said outward movement being to an extent curving said electrode into an outwardly depending arch formation having an arch apex of circumscription height extensible over said targeted tissue when said forward end region is pivoted,

(d2) pivoting said forward end region to a second angular position to, in turn, pivot said electrode over said targeted tissue peripheral extent to a next side thereof opposite said one side,

(d3) effecting retraction of said electrode by urging it rearwardly toward said base region to effect its retracting movement to a retracted orientation below said targeted tissue peripheral extent to effect said electrosurgical cut along three contiguous regions of said targeted tissue peripheral extent;

(e) simultaneously with said step (d) controlling said electrosurgical generator assembly to apply said first output to said electrode in electrical association with said electrosurgical return to establish an electrosurgical cut along said locus of movement of said electrode effective to provide a substantial vascular isolation of said targeted tissue from said viable tissue;

said step (e) including the steps of;

(e1) upon completion of said step (d1), interrupting said first output and expressing said barrier fluid within said electrosurgical cut;

(e2) upon completion of said step (d2), interrupting said first output and expressing said barrier fluid within said electrosurgical cut; and

(e3) upon completion of said step (d3), interrupting said first output and expressing said barrier fluid within said electrosurgical cut.

15. A method for carrying out the necrosis of a volume of targeted tissue exhibiting a given peripheral extent and surmounted by viable tissue, comprising the steps of:

(a) providing an electrosurgical generator assembly having an electrosurgical return, controllable to generate a first output for carrying out electrosurgical cutting of tissue;

(b) providing an instrument electrically coupled with said electrosurgical generator assembly, having a support member extending between a tip and a base region, having a forward end region extending along a longitudinal axis movable with respect to said targeted tissue, and having an electrode at said forward end region with a distal end fixed to said support member actuable for deployment from a retracted orientation to deployed orientations and from said deployed orientations toward a retracted orientation,

said instrument being provided as having a said electrode which is thin and resilient, having a distal end connected with said support member at a connection location adjacent said tip and extending therefrom an arch defining distance;

said instrument deployment portion including an outwardly opening slot extending along said longitudinal axis, and including a membranous flexible anatomically resorbable barrier shroud having an outer edge coupled with said electrode, extending within said deployment portion during said insertion mode and deployable by said electrode;

(c) positioning said instrument forward end region within said viable tissue in adjacency with said targeted tissue peripheral extent with said electrode in a said retracted orientation;

(d) actuating said instrument to deploy said electrode in adjacency with said targeted tissue peripheral extent and thence along and in adjacency with said targeted tissue peripheral extent by pivoting said forward end region and retracting said electrode toward said retracted orientation to describe a locus of movement about said targeted tissue peripheral extent;

said step (d) comprising the actuating steps of;

(d1) urging said electrode forwardly toward said tip in compression to effect its deployment from an initial angular orientation of said forward end region as an outward movement in adjacency with one side of said peripheral extent of said targeted tissue, said outward movement being to an extent curving said electrode into an outwardly depending arch formation having an arch apex of circumscription height extensible over said targeted tissue when said forward end region is pivoted,

(d2) pivoting said forward end region to a second angular position to, in turn, pivot said electrode over said targeted tissue peripheral extent to a next side thereof opposite said one side,

(d3) effecting retraction of said electrode by urging it rearwardly toward said base region to effect its retracting movement to a retracted orientation below said targeted tissue peripheral extent to effect said electrosurgical cut along three contiguous regions of said targeted tissue peripheral extent;

said steps (d1) through (d3) including the deployment of said barrier shroud behind said electrode to effect its positioning within said surgical cut along said three contiguous regions; and

(e) simultaneously with said step (d) controlling said electrosurgical generator assembly to apply said first output to said electrode in electrical association with said electrosurgical return to establish an electrosurgical cut along said locus of movement of said electrode effective to provide a substantial vascular isolation of said targeted tissue from said viable tissue.

16. A method for carrying out the necrosis of a volume of targeted tissue exhibiting a given peripheral extent and surmounted by viable tissue, comprising the steps of:

(a) providing an electrosurgical generator assembly having an electrosurgical return, controllable to generate a first output for carrying out electrosurgical cutting of tissue;

said electrosurgical generator assembly being provided as being controllable to generate a second output for carrying out the coagulation of tissue;

(b) providing an instrument electrically coupled with said electrosurgical generator assembly, having a support member extending between a tip and a base region, having a forward end region extending along a longitudinal axis movable with respect to said targeted tissue, and having an electrode at said forward end region with a distal end fixed to said support member actuable for deployment from a retracted orientation to deployed orientations and from said deployed orientations toward a retracted orientation,

said instrument deployment portion being provided to include an outwardly opening slot extending along said longitudinal axis, said electrode is thin and resilient, having a distal end connected with said support member at a connection location adjacent said tip and extending therefrom an arch defining distance, and including a membranous flexible anatomically resorbable barrier shroud having an outer edge coupled with said electrode, extending within said deployment portion during said insertion mode and deployable by said electrode;

(c) positioning said instrument forward end region within said viable tissue in adjacency with said targeted tissue peripheral extent with said electrode in a said retracted orientation;

(d) actuating said instrument to deploy said electrode in adjacency with said targeted tissue peripheral extent and thence along and in adjacency with said targeted tissue peripheral extent by pivoting said forward end region and retracting said electrode toward said retracted orientation to describe a locus of movement about said targeted tissue peripheral extent;

said step (d) comprising the steps of;

(d1) urging said electrode forwardly toward said tip in compression to effect its deployment from an initial angular orientation of said forward end region, said deployment being an outward, arch defining movement to a first deployed electrode location situated beneath and directed toward adjacency with a first side of said targeted volume of tissue, said deployment commencing the deployment of said barrier shroud;

(d2) pivoting said forward end region about said longitudinal axis to pivotally move said electrode to a second deployed location wherein said electrode is situated beneath and directed toward adjacency with a second side of said targeted volume of tissue opposite said first side, said deployment drawing said barrier shroud outer edge toward said second deployed location;

(d3) urging said electrode further forwardly toward said tip in compression to deploy it outwardly to a third deployed location defining an arch formation having an arch apex of height for pivotal movement over and adjacent to said target volume of tissue, said deployment drawing said barrier shroud outer edge toward said third deployed location;

(d4) pivoting said forward end region about said longitudinal axis to said initial angular orientation to pivotally move said electrode to a fourth deployed location wherein said electrode is situated in aligned adjacency within said first side of said targeted volume of tissue, said electrode movement drawing said barrier shroud outer edge toward said fourth deployed location;

(d5) retracting said electrode by urging it rearwardly to effect its retracting movement into said first deployed electrode location, said retracting movement drawing said barrier shroud outer edge toward said first deployed electrode location;

(f) reiterating said step (d);

(g) simultaneously with said step (f) controlling said electrosurgical generator assembly to apply said second output to said electrode in electrical association with said return to provide electrosurgical coagulation along said electrosurgical cut derived in said step (e); and

(h) severing said shroud from said electrode at a location adjacent said forward edge.

17. Apparatus for electrosurgically cutting a targeted region of tissue, utilizing the output, including a return, of an electrosurgical generator, comprising:

a support member extending between a tip and a base region, having a forward end region extending along a longitudinal axis from said tip and positionable in an insertion mode into adjacency with said targeted region of tissue, and having a deployment portion at said forward end region adjacent said tip;

said support member forward end region being substantially cylindrical and said deployment portion including an outwardly open slot extending along said longitudinal axis from a securement region adjacent said tip to a forward location, thence along a deployment slot region to a rearward location, having a slot width defined between oppositely disposed slot sides extending a slot depth to a slot bottom, including an electrically insulative surface located at said slot sides and bottom,

said support member forward end region slot depth exhibiting a first dimensional extent from said securement region to an output location, and exhibiting a second dimensional extent greater than said first dimensional extent therefrom rearwardly toward said base region,

said support member including a barrier fluid delivery channel having a fluid input in the vicinity of said base region and extending within said slot beneath said electrode to said output location,

a thin, resilient electrode extending within said deployment portion during said insertion mode and deployable to move outwardly from two spaced apart support locations to define an electrode cutting portion and retractable to move toward said deployment portion;

said electrode having a distal end positioned within said slot securement region and extending an arch defining distance beyond said rearward location;

an actuator and electrical circuit assembly extending along said support member from said base region, mechanically connected with said electrode for effecting said deployment and retraction thereof, and having a terminal assembly electrically connectable with said generator for coupling a first said applied output to said electrode providing, in operative association with said return, electrosurgical cutting of said tissue by said electrode along said cutting portion when deployed;

including a forward retainer component positioned over said electrode within said slot securement region and retaining it within said slot, and a rearward retainer component positioned within said slot over said electrode, said electrode being slidably mounted there beneath; and

said actuator assembly being configured to deploy said electrode by urging it forwardly in compression to effect outward movement thereof generally transversely to said longitudinal axis to an extent curving it into an outwardly depending arch formation, and effecting retraction of said electrode by urging it rearwardly to effect inward movement thereof toward said slot.

18. Apparatus for electrosurgically cutting a targeted region of tissue, utilizing the output, including a return, of an electrosurgical generator, comprising:

a support member extending between a tip and a base region, having a forward end region extending along a longitudinal axis from said tip and positionable in an insertion mode into adjacency with said targeted region of tissue, and having a deployment portion at said forward end region adjacent said tip;

said support member forward end region being substantially cylindrical and said deployment portion including an outwardly open slot extending along said longitudinal axis from a securement region adjacent said tip to a forward location, having oppositely disposed slot sides extending a slot depth to a slot bottom, and said forward end region having an electrically insulative, generally channel-shaped retention insert fixed within said slot, having an outwardly opening electrode receiving channel with oppositely disposed internal side surfaces extending a channel depth to a channel bottom, having a securement region extending at a first channel depth from said slot securement end to a forward location, thence extending along a channel deployment region having a second depth, thence having a rearward location with a channel depth corresponding with said first channel depth;

said support member including a barrier fluid delivery channel having a fluid input in the vicinity of said base region and extending within said slot above said electrode to a fluid outlet extending from said rearward location within said retention insert channel deployment region, said fluid outlet having a channel width and a channel slot defining oppositely disposed channel outlet regions;

a thin, resilient electrode extending within said deployment portion during said insertion mode and deployable to move outwardly from two spaced apart support locations to define an electrode cutting portion and retractable to move toward said deployment portion;

said electrode having a distal end fixed with said retention insert securement region at said channel bottom and extending therefrom along said channel deployment region and beyond said rearward location an arch defining distance;

an actuator and electrical circuit assembly extending along said support member from said base region, mechanically connected with said electrode for effecting said deployment and retraction thereof, and having a terminal assembly electrically connectable with said generator for coupling a first said applied output to said electrode providing, in operative association with said return, electrosurgical cutting of said tissue by said electrode along said cutting portion when deployed;

said actuator assembly being configured to deploy said electrode by urging it forwardly in compression to effect outward movement thereof generally transversely to said longitudinal axis to an extent curving it into an outwardly depending arch formation, and effecting retraction of said electrode by urging it rearwardly to effect inward movement thereof toward said slot; and

said actuator assembly being configured to effect movement of said electrode adjacent said rearward location into said channel slot during said outward movement.