U.S. patent application number 10/242777 was filed with the patent office on 2003-01-16 for electrode for electrosurgical ablation of tissue.
This patent application is currently assigned to Oratec Interventions, Inc., a California corporation. Invention is credited to Ashley, John A., Carranza, J. Remberto, Fanton, Gary S., Sharkey, Hugh R..
Application Number | 20030014050 10/242777 |
Document ID | / |
Family ID | 23331715 |
Filed Date | 2003-01-16 |
United States Patent
Application |
20030014050 |
Kind Code |
A1 |
Sharkey, Hugh R. ; et
al. |
January 16, 2003 |
Electrode for electrosurgical ablation of tissue
Abstract
An electrosurgical probe is provided to vaporize, cut, coagulate
or remove tissue from a body structure. A method of surgically
treating a mammal includes providing a surgical instrument
including a length of shaft and an active electrode having a curved
current density edge with at least one convex surface; and ablating
a tissue surface with said surgical instrument.
Inventors: |
Sharkey, Hugh R.; (Woodside,
CA) ; Fanton, Gary S.; (Portola Valley, CA) ;
Ashley, John A.; (San Francisco, CA) ; Carranza, J.
Remberto; (Daly City, CA) |
Correspondence
Address: |
BRIAN J. DORINI
Fish & Richardson P.C.
11th Floor
1425 K Street, N.W.
Washington
DC
20005-3500
US
|
Assignee: |
Oratec Interventions, Inc., a
California corporation
|
Family ID: |
23331715 |
Appl. No.: |
10/242777 |
Filed: |
September 13, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10242777 |
Sep 13, 2002 |
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09340065 |
Jun 25, 1999 |
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6461357 |
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09340065 |
Jun 25, 1999 |
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09022612 |
Feb 12, 1998 |
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6135999 |
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60037782 |
Feb 12, 1997 |
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Current U.S.
Class: |
606/45 ;
606/48 |
Current CPC
Class: |
A61B 2017/320008
20130101; A61B 2018/00625 20130101; A61B 2018/00797 20130101; A61B
2018/1472 20130101; A61B 2218/002 20130101; A61N 1/40 20130101;
A61B 18/148 20130101; A61N 1/06 20130101; A61B 18/1492 20130101;
A61B 2018/00654 20130101; A61B 2018/00702 20130101; A61B 2018/00791
20130101; A61B 2018/00434 20130101 |
Class at
Publication: |
606/45 ;
606/48 |
International
Class: |
A61B 018/14 |
Claims
What is claimed is:
1. A surgical apparatus, comprising: an energy application tip
including: a length of shaft: and an active electrode having a
curved current density edge with at least one convex surface.
2. The surgical apparatus of claim 1, wherein said length of shaft
includes a substantially linear section near the tip.
3. The surgical apparatus of claim 2, wherein said curved current
density edge defines a crossfire pattern.
4. The surgical apparatus of claim 2, wherein said curved current
density edge defines a cloverleaf pattern.
5. The surgical apparatus of claim 2, wherein said curved current
density edge defines an ashtray pattern.
6. The surgical apparatus of claim 2, wherein said curved current
density edge defines a dome pattern.
7. The surgical apparatus of claim 2, wherein said curved current
density edge defines a dome with dimple pattern.
8. The surgical apparatus of claim 2, further comprising an
insulating collar coupled to a distal end of said shaft.
9. The surgical apparatus of claim 8, wherein said length of shaft
includes a return electrode that defines said distal end of said
length of shaft.
10. The surgical apparatus of claim 9, further comprising a return
wire coupled to said return electrode.
11. The surgical apparatus of claim 1, wherein said length of shaft
includes a curved section having a substantially constant radius of
curvature.
12. The surgical apparatus of claim 11, wherein said curved current
density edge defines a crossfire pattern.
13. The surgical apparatus of claim 11, wherein said curved current
density edge defines a cloverleaf pattern.
14. The surgical apparatus of claim 11, wherein said curved current
density edge defines an ashtray pattern.
15. The surgical apparatus of claim 11, wherein said curved current
density edge defines a dome pattern.
16. The surgical apparatus of claim 11, wherein said curved current
density edge defines a dome at with dimple pattern.
17. The surgical apparatus of claim 11, further comprising an
insulating collar coupled to a distal end of said shaft.
18. The surgical apparatus of claim 17, wherein said length of
shaft includes a return electrode that defines said distal end of
said length of shaft.
19. The surgical apparatus of claim 18, further comprising a return
wire coupled to said return electrode.
20. The surgical apparatus of claim 1, wherein said length of shaft
includes an arcuate section.
21. The surgical apparatus of claim 20, wherein said curved current
density edge defines a crossfire pattern.
22. The surgical apparatus of claim 20, wherein said curved current
density edge defines a cloverleaf pattern.
23. The surgical apparatus of claim 20, wherein said curved current
density edge defines an ashtray pattern.
24. The surgical apparatus of claim 20, wherein said curved current
density edge defines a dome pattern.
25. The surgical apparatus of claim 20, wherein said curved current
density edge defines a dome at with dimple pattern.
26. The surgical apparatus of claim 20, further comprising an
insulating collar coupled to a distal end of said shaft.
27. The surgical apparatus of claim 26, wherein said length of
shaft includes a return electrode that defines said distal end of
said length of shaft.
28. The surgical apparatus of claim 27, further comprising a return
wire coupled to said return electrode.
29. The surgical apparatus of claim 1, wherein said length of shaft
includes a curved section having a right angle.
30. The surgical apparatus of claim 29, wherein said curved current
density edge defines a crossfire pattern.
31. The surgical apparatus of claim 29, wherein said curved current
density edge defines a cloverleaf pattern.
32. The surgical apparatus of claim 29, wherein said curved current
density edge defines an ashtray pattern.
33. The surgical apparatus of claim 29, wherein said curved current
density edge defines a dome pattern.
34. The surgical apparatus of claim 29, wherein said curved current
density edge defines a dome with dimple pattern.
35. The surgical apparatus of claim 29, further comprising an
insulating collar coupled to a distal end of said shaft.
36. The surgical apparatus of claim 35, wherein said length of
shaft includes a return electrode that defines said distal end of
said length of shaft.
37. The surgical apparatus of claim 36, further comprising a return
wire coupled to said return electrode.
38. A method of surgically treating a mammal in need thereof,
comprising: providing a surgical instrument including a length of
shaft and an active electrode having a curved current density edge
with at least one convex surface; and ablating a tissue surface
with said surgical instrument.
39. The method of claim 38, wherein ablating said tissue surface
includes scraping said tissue surface.
40. The method of claim 38, wherein ablating said tissue surface
includes sculpting said tissue surface.
41. A surgical apparatus for ablating tissue, comprising: a energy
application tip including: a length of shaft; and a means for
defining a curved current density edge with at least one concave
surface
42. The surgical apparatus of claim 41, wherein said length of
shaft includes a substantially linear section.
43. The surgical apparatus of claim 41, wherein said length of
shaft includes a curved section having a substantially constant
radius of curvature.
44. The surgical apparatus of claim 41, wherein said length of
shaft includes a curved section having an arcuate section.
45. The surgical apparatus of claim 41, wherein said length of
shaft includes a curved section having right angle.
46. A surgical apparatus, comprising: an energy application tip
including: a length of shaft tubing; and an active electrode having
a curved current density edge with at least one convex surface.
47. The surgical apparatus of claim 46, wherein said active
electrode is adjacent an inner surface of said length of shaft
tubing.
48. The surgical apparatus of claim 47, further comprising a return
electrode adjacent an outer surface of said length of shaft
tubing.
49. The surgical apparatus of claim 46, wherein said active
electrode is adjacent an outer surface of said length of shaft
tubing.
50. The surgical apparatus of claim 49, further comprising a return
electrode adjacent an outer surface of said length of shaft
tubing.
51. The surgical apparatus of claim 46, wherein said active
electrode defines a plurality of longitudinal recesses that are
substantially parallel to an axis defined by said length of shaft
tubing.
52. The surgical apparatus of claim 46, wherein said length of
shaft tubing includes a substantially linear section.
53. The surgical apparatus of claim 46, wherein said length of
shaft tubing includes a curved section having a substantially
constant radius of curvature.
54. The surgical apparatus of claim 46, wherein said length of
shaft tubing includes a curved section having a right angle.
55. A surgical system for directing thermal energy to tissue,
comprising: a power supply; a probe coupled to the power supply, by
cabling means, the probe having a handle and a shaft including a
proximal end and a distal end, the shaft having at least one lumen;
an active electrode electrically coupled to the power supply, the
active electrode being positioned on the distal end of the probe,
the active electrode having an energy application surface; and a
return electrode electrically coupled to the power supply.
56. The surgical system according to claim 55, wherein the distal
end includes an insulating base member.
57. The surgical system according to claim 55, wherein the active
electrode is configured for vaporizing a tissue structure.
58. The surgical system according to claim 55, wherein the active
electrode is configured for sculpting a tissue structure.
59. An RF probe comprising: a handle: a shaft coupled to the
handle, the shaft having a proximal end and a distal tip; an active
electrode positioned at or near the distal tip, the active
electrode having a energy application surface; and a return
electrode.
60. The RF probe according to claim 59, wherein the return
electrode is formed from a portion of the shaft.
61. The RF probe according to claim 59, wherein the return
electrode is a grounding pad.
62. A method for vaporizing tissue structures within a body
comprising: providing an RF probe with a distal tip with complex
curves; approximating the RF probe to the tissue structures to be
vaporized; and applying RF energy through the complex curves,
thereby vaporizing the tissue structures.
63. The method according to claim 62, wherein the distal tip is
concavo-convex.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part under 35 U.S.C.
120 of copending U.S. Ser. No. 09/022,612, filed Feb. 12, 1998
which is a continuation-in-part of Ser. No. 60/037.782, filed Feb.
12. 1997 both of which are incorporated herein by reference in
their entirety.
BACKGROUND OF THE INVENTION
[0002] The invention relates to surgical systems applying thermal
energy to biological tissue to modify the characteristics of the
tissue. More particularly, the invention is directed to
electrosurgical probes utilizing radiofrequency (RF) energy to cut,
coagulate, ablate and/or vaporize the tissue during a medical
procedure for treatment and therapy.
[0003] Arthroscopic surgery is becoming increasingly popular,
because it generally does less damage, is less invasive and is
safer than open procedures and produces less scarring in and around
joints. This type of surgery further results in a faster healing
response and a quicker return of the patient to full productivity
while reducing costs of open surgical procedures.
[0004] Nevertheless, arthroscopic surgery has its limitations. The
surgeon must operate through a narrow tube, which is awkward. Only
one probe can be used at a time. Often the viewing camera is
positioned at an angle which is different from the surgeon's normal
gaze. This contrasts with "open surgery" where the surgeon has
relative ease of viewing the surgical site and can freely move both
hands, even utilizing the hands of colleagues.
[0005] In view of such difficulties of arthroscopic surgery, it is
understandable that laser, microwave and radiofrequency (RF) probes
which simultaneously cut and coagulate are preferred. However,
current probes are poorly adapted to certain activities, such as
cutting narrow tendons or ligaments. Current probes have convex,
pointed and/or flat tips. Other probes such as those utilizing
laser energy delivery systems often provide pointed tips with
curved configurations, with current probes, the surgeon has little
control when pressing against a tough ligament. Now as the surgeon
cuts through one portion of the ligament, the probe slips out of
position. The surgeon must reapproximate the probe and cut again,
an inefficient process. Unless the surgeon is able to stop pressure
at exactly the right time, the probe may slip and cut an adjacent
structure. Because the surgeon must repeatedly reapproximate and
cut the ligament, the surgeon has difficulty in cleanly ablating
the ligament or tendon. Thus, there are certain procedures that
surgeons still prefer to perform in an open setting which is
conventionally termed an "open" procedure. Unfortunately, this
often results in large scars, long convalescence, and even more
irritation of an already irritated joint.
[0006] What is needed is a probe that can simultaneously direct the
tendon to the energy source (e.g., RF) and apply RF to cleanly and
smoothly ablate the tendon or ligament. The advantage is that some
procedures that have been considered too awkward or difficult to
perform by arthroscopy can now be performed more effectively using
arthroscopic devices.
[0007] Moreover, conventional and more complex surgical probes and
lasers are less suitable for critical and precise shaping and
sculpting of body tissues such as articular cartilage, ligaments
and tendons. Target tissues subject to ablation and removal have
many different configurations and structures. These medical device
probes and lasers have further disadvantages of being configured
for simple ablation without regard to the contour and structure of
the target tissue. By universally applying RF energy to the site,
non-target tissue may be affected by collateral thermal
effects.
[0008] For these reasons it would be desirable for an apparatus and
method to selectively cut and ablate body tissue during a medical
procedure such as arthroscopic surgery. The apparatus and method
should be configured and used for effective cutting, ablation and
vaporization of target tissue while giving the surgeon a precise
and controlled surface for scraping tissue from bone or sculpting
tissue within the surgical field for appropriate treatment and
therapy. Such apparatus and methods should also be applicable in a
wide variety of medical procedures on a wide range of different
bodily tissues. The apparatus should also be simple and less
expensive to manufacture while being compatible with conventional
systems and procedures.
SUMMARY OF THE INVENTION
[0009] One embodiment of the invention is based on a surgical
apparatus, comprising: an energy application tip including: a
length of shaft; and an active electrode having a curved current
density edge with at least one convex surface.
[0010] Another embodiment of the invention is based on a method of
surgically treating a mammal in need thereof, comprising: providing
a surgical instrument including a length of shaft and an active
electrode having a curved current density edge with at least one
convex surface; and ablating a tissue surface with said surgical
instrument.
[0011] Another embodiment of the invention is based on an
electrosurgical system for directing thermal energy to tissue is
disclosed which has a power supply and a probe. The probe is
coupled to the power supply by a cabling means and has a handle and
a shaft including a distal end and a proximal end. The shaft has at
least one lumen for an active electrode electrically coupled to the
power supply, the active electrode being positioned on the distal
end of the probe, the active electrode having an energy application
surface; and a return electrode electrically coupled to the power
supply.
[0012] These, and other, goals and embodiments of the invention
will be better appreciated and understood when considered in
conjunction with the following description and the accompanying
drawings. It should be understood, however, that the following
description, while indicating preferred embodiments of the
invention and numerous specific details thereof, is given by way of
illustration and not of limitation. Many changes and modifications
may be made within the scope of the invention without departing
from the spirit thereof, and the invention includes all such
modifications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a lateral view of internal structures within the
glenohumeral joint.
[0014] FIG. 2 is a medial side view of the knee joint.
[0015] FIG. 3 is an anterior view of the knee joint with the
patella removed.
[0016] FIG. 4 is a perspective view of a concave cutting tip of a
RF probe.
[0017] FIG. 5 is a perspective view of the concave cutting tip of
FIG. 4 inserted into the shaft portion of the RF probe.
[0018] FIGS. 6A-B are side views of the concave cutting tip of the
RF probe of FIG. 4.
[0019] FIG. 6C is an alternative embodiment of the concave cutting
tip of the RF probe.
[0020] FIGS. 7-11 show different monopolar and bipolar arrangements
of the electrodes on the concave cutting tip.
[0021] FIGS. 12A-C show an overview of a RF probe, operating
cannula and a side, cross-sectional view of the shaft portion of
the RF probe.
[0022] FIG. 13A illustrates an alternate embodiment of a probe with
cutting tip.
[0023] FIG. 14A is a simplified, side view of the probe according
to the invention;
[0024] FIGS. 14B-14F show alternative tip configurations of the
probe.
[0025] FIGS. 15A-C are isometric, top and cross-sectional views,
respectively, showing one embodiment of an active electrode and an
energy application tip of the probe according to the invention.
[0026] FIGS. 15D-F are isometric, top and cross-sectional views,
respectively, showing an alternate embodiment of the active
electrode.
[0027] FIGS. 15G-I are isometric, top and cross-sectional views,
respectively, showing an alternate embodiment of the active
electrode and distal tip of the probe.
[0028] FIGS. 16A-F are side and isometric, perspective views of
different embodiments of the probe according to the invention.
[0029] FIG. 17A is a cross-sectional view of one of the distal
energy application tips and active electrode of the probe according
to the invention.
[0030] FIGS. 17B-C are side views of different embodiments of the
probe.
[0031] FIG. 18A is a cross-sectional view of an alternative
embodiment of the distal energy application tip and active
electrode of the probe according to the invention.
[0032] FIG. 18B is an isometric perspective view of the probe.
[0033] FIGS. 19A-B are side, cross-sectional views of an
alternative embodiment of the distal energy application tip and
active electrode of the probe according to the invention.
[0034] FIGS. 20A-B are side, cross-sectional and isometric
perspective views, respectively, of the probe of the invention.
DESCRIPTION OF SPECIFIC EMBODIMENTS
[0035] The invention arose out of an observation that, during an
arthroscopy procedure, the surgeon could not access and cut cleanly
the coracoacromial (CA) ligament shown in FIG. 1. This procedure is
done in conjunction with a subacromial decompression, which makes a
painful shoulder easier to move. If the cutting probe slips, the
joint capsule could be damaged and even punctured, which would
exacerbate an already painful joint. Thus, a concave rounded tip
was designed which would center and position ligaments and could
even be used to lift the ligament away from adjacent structures and
avoid harm thereto.
[0036] This new style of tip has the advantage of being able to
mechanically "gather" or constrain ligaments, tendons and other
tissue into its center. This reduces the natural tendency of
current cutting probes to slide off ligaments and tendons. This
helps save time in that the surgeon is not repeatedly trying to
center or approximate the probe tip on the target tissue.
[0037] FIG. 1 show s a lateral (side) view of a glenohumeral joint
100 and in particular the Coracoacromial ligament 102, the Superior
glenohumeral ligament 104, the middle oienohumeral ligament 106,
the Subscapularis Tendon 108 (joined to capsule), the Inferior
Glenoheumeral ligament 110, the Glenoid "cup" with cartilage 112,
the Joint Capsule 114, and the Bursa 116. The Joint Capsule 114 is
comprised of 3 glenohumeral ligaments and surrounding capsule. The
Bursa 116 lubricates and acts like a shock absorber, and is usually
removed when an SA decompression is performed. The area 118 is the
area at which impingement usually occurs.
[0038] FIG. 2 shots s a medial (side) view of a patellofemoral or
knee joint 200, and in particular the Medial Collateral Ligament
202, the patella 204, the Medial Lateral Retinaculum 206, an
incision line 208 for lateral release and the Patellar Ligament
210.
[0039] FIG. 3 illustrates an anterior view of the knee joint 200
with the patella removed. The bones comprising the knee joint 200
are the femur 240, the fibula 250 and the tibia 260. The joint is
connected by ligaments, in particular, the anterior cruciate
ligament 200 and the posterior cruciate ligament 230. As the knee
is flexed, the lateral condyle of the femur 241 and the medial
condyle of the femur 242 articulate and pivot on the meniscal
surfaces of the tibia, in particular the lateral meniscus 231 and
the medial meniscus 232, respectively. The meniscal surface
comprises articular meniscal cartilage which acts as the shock
absorber for the knee.
[0040] While coracoacromial surgery was the inspiration for this
invention, use of this concave probe is not limited to a particular
ligament or tendon, or even to those soft tissues. The concave
cutting probe is adapted to cut all types of tendons, ligaments and
soft tissues more effectively than blunt or rounded tip probes. As
another example whose anatomy is shown in FIG. 2, the lateral
retinaculum 206 sometimes must be severed in some types of patellar
dislocation or malignment, when the patella is not properly
tracking in the trochlear notch. Severing the lateral retinaculum
is called lateral retinacular release. With this concave-tip probe,
the surgeon is able to position the ligament and sever it
cleanly.
[0041] The probe of the invention may also be used in the knee
joint during a notchplasty procedure for anterior cruciate ligament
repair. The probe configuration of the invention, in particular the
energy application tip configuration is used to remove and scrape
the condylar surfaces of the femur to increase the interchondylar
notch to free the anterior cruciate ligament from impingement. The
anterior cruciate ligament may also be cut at point 221 and removed
using the probe and a patellar tendon graft may be performed.
[0042] Turning note to the probe itself, FIG. 4 shows a concave
edge 308 on a distal tip 304 of an RF probe head 300. This concave
edge is designed to constrain tissue, tendons and ligaments. The
concave curve has lateral edges 306 which are rounded, so that the
probe does not "snag" on unwanted tissue as the surgeons maneuvers
the probe into position. The cylindrical portion 302 of the distal
tip 304 fits inside probe sheath 410, as shown in FIG. 5. The
distal tip may have a variety of configurations, as shown in FIGS.
4-11. FIG. 5 shows probe 400 having a concave edge with less
prominently rounded lateral edges. FIGS. 5-7 show a distal tip
which is angled with respect to the sheath 410. This embodiment
offers the advantage of helping the surgeon get around corners and
ablate in narrow or confined spaces.
[0043] FIG. 6A shows an angled probe 500 consisting of a
cylindrical portion 502 with a distal tip 504 having a concave edge
508 and lateral edges 506. FIG. 6B shows a side view of angled
probe 500.
[0044] FIG. 6C shows an angled probe 600 with a specialized surface
(not heated) which imparts a third function to the probe, namely
scraping tissue. Probe 600 is comprised of a cylindrical portion
602, and a distal tip 604 which has a concave edge 608 and lateral
edges 606. The surface of the flat portion of distal tip 604
contains rasps 616 which can be used for scraping tissue.
[0045] For cutting tissue, the distal tip has a first electrode and
a second electrode located on lateral edges 606. The first and
second electrodes can be operated in bipolar or monopolar mode.
Bipolar is preferred and examples of "Taser" type electrodes are
shown in FIGS. 7 and 8.
[0046] FIG. 7 shots s a distal tip 700 having a three-pole, bipolar
arrangement where, in addition to two side positive electrodes 702
and 706, there is a central negative electrode 704. FIG. 8 shows a
distal tip 800 wherein two electrodes 802 and 806 are positioned in
two small sites on the lateral edges of the concave curve. In this
particular embodiment, electrode 802 is positive and electrode 806
is negative
[0047] FIGS. 9-11 show exemplary monopolar arrangements. In FIG. 9,
a single monopolar positive electrode 902 occupies a wide portion
of the concave curve of distal tip 900. A return path 904 is
provided and is attached to the patient's body to complete the
circuit. In FIG. 10, there is one small active electrode 1006
located centrally on distal tip 1000. In FIG. 11 there are two
active electrodes 1102 and 1106 in lateral positions on distal tip
1100. Suffice it to say that quite a variation in electrode design
is contemplated for this concave curve.
[0048] To maintain the appropriate temperature for cutting tissue,
the distal tip of the probe may also be equipped with a
thermocouple, but such a thermocouple is optional in the
concave-tipped probe.
[0049] FIG. 12 illustrates a simplified view of the RF probe of the
invention. FIG. 12A is an illustration of a conventional cannula
utilized in one embodiment of the invention. Cannula 1202 consists
of a guide 1224 with an opening 1226 at its distal end. Cannula
1202 is attached at its proximal end to introducer 1222. Instrument
port 1228 is located at the proximal end for the introduction of
the surgical probe. Cannula 1202 man also have an extension 1232
with a fluid port 1234. As illustrated in FIG. 12B, surgical
instrument 1200 consists of a handle 1212 to which is attached a
power cord 1210, a probe shaft 1214 and a probe tip 1216. During
introduction into the body, a blunt insert or obturator (not shown)
is inserted through instrument port 1228. Cannula 1202 is inserted
into the surgical site on the patient functioning as a trocar.
Surgical instrument 1200 is then inserted into cannula 1202 through
instrument portal 1228 so that the tip 1216 protrudes from the
opening 1226 in cannula 1202.
[0050] FIG. 12C illustrates a side, cross-section of the probe
shaft 1214. Probe handle 1212 is connected to shaft tubing 1242.
Shaft tubing insulator 1241 covers the shaft tubing. The shaft
tubing insulator 1421 may be any biocompatible material such as
Teflon or any other suitable material such as nylon shrink tubing.
Power wire 1260 is connected to a power supply (not shown) in the
proximal portion of the probe and probe handle 1212. Power
insulator 1267 covers and insulates power wire 1260. The power
insulator 1267 material is preferably a tubing such as Teflon or
polyimide but may also include any other insulator material which
would be known by a person skilled in the art such as a coating.
Power wire 1260 connects the power supply to an active electrode
(not shown) on the distal energy application tip 1250. The power
wire may be stainless steel, titanium, tugsten, copper or any other
compatible and suitable conductor. A return wire 1261 connects a
return electrode (not shown in FIG. 12) to the power supply. The
energy application tip 1250 has an energy application surface 1255.
The energy application surface 1255 is configured to have a variety
of configurations such as concave, convex or concavo-convex for the
delivery of thermal energy to the soft tissue site. Probe shaft
tubing, 1242 may also have a bent portion 1251 which may be
configured for easier access to narrow or confined joint
spaces.
[0051] FIGS. 13A-B show an enlarged view of one embodiment of the
tip 1510 of an electrosurgical instrument wherein two opposing
arcuate segments 1504A and 1504B are compressed to form a probe tip
1216A at the distal end of probe 1214A. In such an embodiment,
swagging is used to compress the tip of the probe. Swagging forms a
chisel 1514 that can be used in the surgical instrument of FIGS. 12
and 13 for RF ablation of tissue. Grinding applications can be
added to the tip to provide for mechanical tissue ablation in
addition to energy ablation. The core 1502 of probe 1214A can be
either hollow or solid. This particular embodiment is illustrated
as having an annular probe. Probe 1214A is coated in an insulating
material which terminates prior to the tip 1510, leaving chisel
1514 exposed. The surgical probe illustrated in FIGS. 13A-B
provides various improvements over the prior art in allowing for
precise hemostatic cutting and ablation of soft tissue in one
convenient instrument which can be described as a chisel. The
malleable probe tips can be configured as straight, angled or
curved, for example, which provides for optimal access to specific
anatomy and pathology. Unique tip designs improve tactile feedback
for optimal control and access, and provide for improved tissue
visualization with greatly reduced bubbling or charring.
[0052] Another embodiment of surgical probe of the invention is
illustrated in FIGS. 14A-F. FIG. 14A illustrates a simplified side
view of the surgical probe for the delivery of thermal energy to a
tissue site. FIGS. 14B-F shots Various alternative embodiments of
the energy application tip. The configuration of the probe shaft
allows the surgeon to have better access and more selective control
while in the operating environment. For example. FIG. 14D is
particularly suitable for use in an arthroscopic acromioplasty
wherein the coracoacromial ligament is cut and associated tendons
are removed. The right angle of the energy application tip allows
the surgeon to scrape target tissue from the underside of the
acromion. The various other configurations and geometries of the
energy application tip as shown in FIGS. 14B-14F allow the surgeon
to operate in a variety of arthroscopic procedures to access
various joint geometries within the body. The probe may also be
malleable to allow the surgeon to adjust the distal tip for an
individual and procedure.
[0053] FIGS. 15A-15C illustrate one embodiment of the distal energy
application tip of the probe according to the invention. The energy
application surface comprises an active electrode 1520 in the form
of a "cross" or "crossfire" for the delivery of electrical energy
to a tissue site during a surgical procedure. The electrical
characteristics of this cross-shape design and configuration of the
active electrode 1520 condenses and concentrates the electrical
current density at defined current density edges 1529 along
cross-shape on the distal tip. The return electrode 1523 is also
located near the distal energy application tip such that a unipolar
arrangement for RF energy delivery is described. An insulating
collar 1525 separates active electrode 1520 from return electrode
1523.
[0054] Turning to FIG. 15C, power wire 1560 delivers energy from
the power source to the active electrode 1520. Power insulator 1567
insulates the power ire inside the probe and between the shaft
tubing and electrodes. Insulating collar 1525 insulates the active
electrode 1520 from the return electrode 1523 which may be formed
from a portion of the shaft tubing or a separate electrode on the
distal tip. Alternatively, a separate return electrode structure
may be used which is separate from the distal energy application
tip. The current travels between the active electrode and the
return electrode through the irrigation solution or through the
tissue.
[0055] For example, it will be appreciated by one skilled in the
art that in an alternating current system, the generated and
delivered high frequency RF energy (greater than 300 kHz) will
alternate between the active electrode 1520 and the return
electrode 1523. By using a larger surface area return electrode in
proportion to the active electrode, the RF energy is diffuse in the
area of the return electrode. When the energy is applied to the
distal energy application tip, heat is generated at the sharp edges
1529 of active electrode 1520 activating the entire electrode
surface while heat is minimized at the return electrode 1523
through diffusion. Because electrical current is condensed and
concentrated on a smaller area, heat is generated at a directed and
desired area such as the target tissue in contact with the energy
application tip. This allows the surgeon to cut and ablate the
target tissue in a more efficient manner when the tissue causes an
increase in impedance between the two electrodes. The cross
configuration and edges 1529 also provides a specific mechanical
surface for a physical scraping function of the active electrode.
The tissue and standard irrigation in the surgical joint complete
the circuit between the two electrodes and the tissue is
mechanically and thermally cut and ablated allowing the surgeon to
vaporize the target tissue such as when removing a soft cartilage
tissue from bone.
[0056] Thus, the distal energy application tip of the invention may
be further described as "unipolar" or "sesquipolar" whereby one
electrode has a different electrical potential than the other
electrode. In a true bipolar system, each electrode would have
equal potentials and equal effects when electrical energy is
applied to the active electrodes. In the invention, the active
electrode generates heat by condensing the RF energy at the sharp
edges causing cutting, ablation and vaporization while the return
electrode generates little heat. It will also be appreciated that
due to the high frequency current, these distal energy application
tips and active electrode designs may be used in conventional
monopolar surgical systems where the return electrode is located on
the patient's body.
[0057] FIGS. 15D-F illustrate another embodiment of the distal
energy application tip 1500 of the invention wherein the active
electrode 1530 is constructed in a "cloverleaf" configuration. As
described in FIG. 15A, the RF energy is condensed and directed
through current density edges 1529 towards the target tissue.
Active electrode 1530 has the mechanical advantage of a greater
scraping ability by providing a sharp current density edge 1539.
Power wire 1560 is covered with power insulator 1567 and delivers
energy to the active electrode 1530. It will be appreciated that
all current density edges will have the same current potential
whereby the potential for an ablation and vaporization effect is
uniform at all tissue contact points.
[0058] FIGS. 15G-I illustrate another embodiment of the distal
energy application tip 1500 of the invention wherein the active
electrode 1540 is an "ashtray" configuration. As described in FIG.
15A, the RF energy is condensed and directed through current
density edges 1549 towards the target tissue. Active electrode 1540
has a further mechanical advantage of a greater scraping ability by
providing a sharp current density edge 15539 while having a thermal
energy effect at the current density edges 1539. Power wire 1560 is
covered with power insulator 1567 and delivers energy to the active
electrode 1540. It will be appreciated that all current density
edges will have the same current potential whereby the potential
for an ablation and vaporization effect is uniform at all tissue
contact points. As the RF power is delivered to the active
electrode, the target tissue in contact with the surface of the
current density edges 1539 is uniformly cut and ablated for removal
from the joint. FIG. 15I also shows the power wire 1560
alternatively coupled to the distal tip 1540 by means of an
intermediate couple wire 1580.
[0059] It will also be appreciated that the active electrode can be
brazed, crimped soldered, welded or mechanically attached by means
of a spring clip to the power wire. One alternative attachment
means includes providing an active electrode with a hole. When the
electrode is heated, the hole expands and the power wire is
inserted into the hole. As the electrode tip cools, the diameter of
the hole will decrease thereby effectively crimping the electrode
tip to the power wire. Further, the active electrode may consist of
titanium, tungsten and their alloys or stainless steel and the
power wire may consist of stainless steel in a variety of tensile
strengths, titanium, copper or any suitable alloys thereof. The
active electrode tip may also be machined, stamped, cast into shape
or metal injection molded to form the desired configuration with
current density edges.
[0060] FIG. 16A-B show side and perspective views of ashtray
electrode configured for sculpting soft tissue attached to bone or
any other soft tissue within the body. The distal energy
application tip is arcuate such that the shaft tubing is bent
between 0 and 90 degrees. The shaft 1624 is preferably 30 degrees
to provide an angle for sculpting the soft tissue by ablation. In
this embodiment, the return electrode 1623 is formed from the
distal portion of the shaft tubing and electrically connected to
the power supply to act as the return in a unipolar
configuration.
[0061] As shown in FIG. 16A, the current density edge 1629 has
cutouts or gaps whereby the RF energy is focused primarily on the
external edges of the active electrode thereby heating up specific
areas of target tissue adjacent to the probe. As the power level of
the RF energy increases, the target tissue is cut and ablated in a
consistent pattern to vaporize the tissue along the current density
edge 1629 as the surgeon manipulates the probe within the surgical
field.
[0062] In FIGS. 16C-D, the active electrode is shown in an
alternative embodiment having a dome structure with a convex
surface for ablation and vaporization. Active electrode 1630 has a
simple base with a dome defining a broad surface current density
edge. As the RF power is applied to the active electrode, the
target tissue is sculpted in a smooth and consistent ablation.
Surgical procedures using a smoothing ablation and vaporization
include meniscal repair and capsulotomy where extra cartilage and
ligament material can irritate the joint if it is not cut out and
removed by ablation and vaporization.
[0063] FIGS. 16E-F illustrate an alternative embodiment wherein the
dome of FIGS. 16C-D has a dimple within the convex dome structure.
As the vaporization occurs, constant bubble streams with small
bubbles resulting from cellular destruction and dessication obscure
the operating field and arthroscope where the surgeon views the
arthoscopic procedure. The dimple allows the bubbles to collect and
form a larger bubble which is then released from the void defined
by the dimple at an infrequent rate. This allows the surgeon to
have an unobstructed view of the tip while still allowing the
energy application tip 1600 to deliver RF energy to the active
electrode so as to effect ablation. Current density edges 1649
provide for a condensation and concentration of RF energy along the
edges of the active electrode 1640 to heat up the target tissue in
contact with the edges thereby causing ablation and
vaporization.
[0064] Turning to FIG. 17A, the distal energy application tip 1700
is illustrated in a detailed cross-section. The active electrode
1710 is provided in an ashtray configuration. The current density
edges 1719 are located on a distal portion of the active electrode.
Gap portions 1712 allow the RF energy to be condensed and
concentrated at the current density edges 1719. The active
electrode 1710 is inserted into an insulating collar 1715 for
attachment to the distal end of the shaft tubing 1742.
[0065] In a unipolar setting the return electrode 1742 is located
near the end of the distal tip of the shaft tubing 1742.
Alternatively, the return electrode 1742 may be formed from a
portion of the shaft tubing 1742 thereby allowing for a simpler
construction. Shaft insulation 1741 insulates the shaft in
conjunction with insulating collar 1715. Power wire 1760 delivers
the RF energy to the active electrode from the power supply and is
located within the shaft tubing lumen 1780. Return wire 1761 is
coupled to return electrode 1713 to function as a return to the
power supply.
[0066] FIGS. 17B-C show alternative embodiments of the shaft with
the ashtray active electrode. FIG. 17B illustrates the ashtray
active electrode being configured for sculpting the target tissue
wherein the distal end of the shaft 1734 is bent to a right angle.
The active electrode 1720 with current density edges 1729 is
located on the distal portion of shaft 1724. The return electrode
1723 is separated from active electrode 1720 by insulating collar
1725.
[0067] FIG. 17C illustrates the ashtray active electrode being
configured for scraping target tissue from bone. The active
electrode 1730 with current density edges 1739 is located on the
distal portion of shaft 1734. The return electrode 1733 is
separated from active electrode 1730 by insulating collar 1735.
[0068] FIG. 18A-B shows a detailed cross-section and perspective
view of the distal energy application tip 1800 with a
cross-configured active electrode 1810. In an exemplary embodiment
the active electrode 1810 is insulated from return electrode 1813.
The return electrode 1813 may also be formed from a portion of the
shaft tubing 1842. Power wire 1860 located within the shaft tubing
lumen 1880 delivers RF energy to the active electrode 1810. The
current density edges 1819 provide a surface for the current to
condense causing ablation and vaporization of the target tissue.
Shaft insulation 1841 protects and insulates shaft tubing 1842.
[0069] FIG. 19A-B illustrate another embodiment of the active
electrode wherein the distal energy application tip 1900 is
configured for grating. In this embodiment, active electrode 1910
is a ring electrode with a continuous current density edge 1919. In
this configuration, the active electrode defines a lumen 1985 with
insulator block 1962 forming the back wall portion of the lumen.
Insulator collar 1915 insulates the active electrode 1910 from the
return electrode 1913. Insulator collar 1915 is attached to the
distal portion of shaft tubing, 1942. The shaft 1914 is covered in
shaft insulator 1941. In FIG. 19B, the return electrode 1903 is
located within active electrode lumen 1985. In this configuration,
a boiling chamber is created wherein any additional material that
is grated and scraped into the lumen and not fully ablated or
vaporized will increase the impedance between the active and return
electrodes to cause further vaporization. As the ring electrode is
placed against target tissue and RF energy is delivered through
power wire 1960, ablation and vaporization occurs at the current
density edge 1919.
[0070] FIG. 20A-B illustrate an alternative embodiment of the
distal energy application tip 2000 wherein the active electrode
2010 has a complex teeth structure for mechanical gratings during
ablation and vaporization. In this embodiment, the active electrode
2010 is formed from by machining or cutting curves or teeth into
the ring electrode. In this configuration, the current density
edges 2019 provide a tooth-like grater to mechanically scrape the
target tissue. RF power is delivered by power wire 2060 through
insulating block 2062. The active electrode 2010 is insulated from
return electrode 2013 by insulating collar 2015. The insulating
collar 2015 is located on the distal portion of shaft tubing 2042
which is insulated by shaft insulator 2041. Return wire 2061 is
coupled to return electrode 2013 to function as a return to ground
at the power supply. While shaft 2014 is shown as linear, it may be
malleable or pre-bent to allow for appropriate access and control
within the surgical environment.
EXAMPLE
[0071] Lateral retinacular release as mentioned above can be
accomplished with the use of the concave-tipped RF probe as shown
in FIG. 4. First, the knee joint is distended with a clear fluid,
usually saline. Initial distention can be done using a large
syringe full of saline which is injected into the joint space.
Distention forces the bones of the joint apart creating room to
introduce instrumentation without damaging the cartilage.
[0072] Once the instrumentation has been inserted into the joint
space, the irrigation tubing and cannulas are positioned and hooked
up to provide continual fluid exchange during the procedure. The
most common systems are gravity flow or the use of an arthroscopic
pump. By hanging bags of irrigation fluid on an IV pole and raising
them 3-4 feet above the operative site, flow to the joint can be
accomplished. Elevation of the supply bag is enough to create
pressure to distend and irrigate the joint. The fluid enters the
joint through the scope sheath and exits through a cannula placed
in the superior lateral portal, or the reverse, through the cannula
and out through the scope sheath. The setup is a matter of
physician preference. The key to the proper function of either
system is that the inflow volume must be larger than the outflow
volume. This restriction in the outflow is what creates the back
flow that distends the joint.
[0073] With an arthroscopic pump, the bags do not need to be raised
on an IV pole. The factors controlling distention of the joint are
controlled automatically by the pump. The pump monitors the fluid
pressure in the joint space using a pressure sensing cannula and
automatically increases or decreases fluid flow as needed to
provide optimum viewing. As with the gravity flow system, fluid
enters the joint cavity through the scope sheath or the cannula in
the superior lateral portal. Such an arthroscopic procedure
requires the creation of two to five portals (entry ways) into the
joint capsule. To create a portal, the surgeon usually begins by
making a small stab wound with a scalpel (e.g.. No. 11 or 15 blade)
at the site of the portal. Next, the wound is enlarged and extended
with a trocar encased in a sleeve (cannula) through muscle tissue
to the synovial membrane. The trocar is removed, leaving the
cannula in place. Then, the surgeon uses a blunt obturator (to
avoid damage to menisci and articular cartilage) to puncture
through the synovium into the joint cavity. The obturator is
removed and the cannula left in place. The cannula can be used to
insert an arthroscope or for the inflow and outflows of water. If
the surgeon elects to insert instruments percutaneously, the sleeve
is removed. For lateral retinacular release, the surgeon frequently
uses three portals, one for the arthroscope, one for the instrument
and one for the drain. Additional portals may be created for the
surgeon to access other areas of the knee (i.e., to tighten the
medial retinaculum) during the procedure. Frequently, a
superolateral (above and to the side of the patella) approach is
used for the irrigation cannula. For the arthroscope and concave
probe, anteromedial and anterolateral approaches often are chosen,
because they are relatively safe (minimal potential tissue damage)
and most surgeons have more experience with them. Once the
arthroscope is viewed, the surgeon may use the concave-tipped probe
(without power) to advance to the site of the lateral retinaculum.
Having located the lateral retinaculum, the surgeon activates the
RF probe and cuts entirely through the ligament.
[0074] The foregoing description of a preferred embodiment of the
invention has been presented for purposes of illustration and
description. It is not intended to be exhaustive or to limit the
invention to the precise forms disclosed. Obviously, many
modifications and variations will be apparent to practitioners
skilled in this art. It is intended that the scope of the invention
be defined by the following claims and their equivalents.
[0075] All publications and patent applications mentioned in this
specification are herein incorporated by reference to the same
extent as if each individual publication or patent application was
specifically and individually indicated to be incorporated by
reference.
[0076] While the invention has been described with respect to its
preferred embodiments, it will be appreciated that other
alternative embodiments may be included. For example, with respect
to all of the explicitly disclosed embodiments, as well as all
other embodiments of the invention, monopolar implementation may be
achieved by replacing the return electrode on the probe with a
separate return electrode, or alternatively, simply providing an
additional electrode as a return electrode on the body of a patient
electrically utilizing the return electrode on the probe. These and
various other modifications can be made to the disclosed embodiment
without departing from the subject of the invention.
* * * * *