U.S. patent application number 10/875484 was filed with the patent office on 2005-02-10 for irrigation probe for ablation during open heart surgery.
Invention is credited to Fuimaono, Kristine B..
Application Number | 20050033221 10/875484 |
Document ID | / |
Family ID | 32712865 |
Filed Date | 2005-02-10 |
United States Patent
Application |
20050033221 |
Kind Code |
A1 |
Fuimaono, Kristine B. |
February 10, 2005 |
Irrigation probe for ablation during open heart surgery
Abstract
An irrigation ablation probe comprises a generally rigid probe
body and a handle mounted to the proximal end of the probe body.
The generally rigid probe body comprises an ablation electrode at
its distal end having at least one irrigation opening through which
fluid can pass. An infusion tube extends through the probe body for
introducing fluid into the ablation electrode. The irrigation
ablation probe is useful for treating atrial fibrillation during
open heart surgery.
Inventors: |
Fuimaono, Kristine B.;
(Medford, NJ) |
Correspondence
Address: |
PHILIP S. JOHNSON
JOHNSON & JOHNSON
ONE JOHNSON & JOHNSON PLAZA
NEW BRUNSWICK
NJ
08933-7003
US
|
Family ID: |
32712865 |
Appl. No.: |
10/875484 |
Filed: |
June 24, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10875484 |
Jun 24, 2004 |
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09370601 |
Aug 10, 1999 |
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Current U.S.
Class: |
604/34 |
Current CPC
Class: |
A61B 2018/00029
20130101; A61B 18/1482 20130101; A61B 2018/00821 20130101 |
Class at
Publication: |
604/034 |
International
Class: |
A61M 001/00 |
Claims
That which is claimed is:
1. An irrigation ablation probe comprising: an elongated probe body
comprising an elongated ablation electrode having proximal and
distal ends and defining an inner cavity, the elongated ablation
electrode having at least one irrigation opening through which
fluid can pass from the inner cavity to the outside of the
elongated ablation electrode, the elongated ablation electrode
being generally rigid from its proximal to its distal end so that
the ablation electrode cannot bend during ablation, and wherein the
elongated ablation electrode has an exposed distal portion that is
generally straight and forms an angle a greater than 0.degree. with
the remainder of the elongated probe body, the angle a being
preformed; and an infusion tube attached to the proximal end of the
elongated ablation electrode for introducing fluid into the inner
cavity.
2. An irrigation ablation probe according to claim 1, wherein the
elongated ablation electrode extends the entire length of the
elongated probe body.
3. An irrigation ablation probe according to claim 1, further
comprising a non-conductive sheath positioned on the elongated
ablation electrode and configured to define the exposed distal
portion.
4. An irrigation ablation probe according to claim 3, wherein the
elongated ablation electrode has a length greater than a length of
the non-conductive sheath.
5. An irrigation ablation probe according to claim 1, further
comprising a handle mounted at the proximal end of the elongated
probe body, the handle comprising a housing having a generally open
interior receiving a proximal end of the elongated ablation
electrode.
6. An irrigation ablation probe according to claim 1, wherein the
elongated ablation electrode remains in a fixed position relative
to the elongated probe body and operation of the probe.
7. An irrigation ablation probe according to claim 1, wherein said
infusion tube includes a coupling on its proximal end for
connection to a source of fluid.
8. An irrigation ablation probe according to claim 1, wherein the
elongated probe body comprises a malleable material.
9. An irrigation ablation probe comprising: an elongated probe body
comprising an elongated tubular ablation electrode having proximal
and distal ends and defining an inner cavity, the elongated
ablation electrode having at least one irrigation opening through
which fluid can pass from the inner cavity to the outside of the
ablation electrode, the elongated probe body being generally rigid
from its proximal end to its distal end so that the probe body
cannot bend during ablation, and wherein the elongated ablation
electrode is generally rigid and has an exposed distal portion that
is generally straight and forms an angle a greater than 0.degree.
with the remainder of the elongated probe body, the angle .alpha.
being preformed; and an infusion tube having proximal and distal
ends and extending through the elongated probe body for introducing
fluid into the inner cavity of the elongated ablation electrode,
the distal end of the infusion tube being attached to the elongated
ablation electrode.
10. An irrigation ablation probe according to claim 9, wherein the
elongated ablation electrode extends the entire length of the
elongated probe body.
11. An irrigation ablation probe according to claim 9, further
comprising a non-conductive sheath positioned on the elongated
tubular ablation electrode and configured to define the exposed
distal portion.
12. An irrigation ablation probe according to claim 11, wherein the
elongated ablation electrode has a length greater than a length of
the non-conductive sheath.
13. An irrigation ablation probe according to claim 9, further
comprising a handle mounted to the proximal end of the elongated
probe body, the handle comprising a housing having a generally open
interior receiving a proximal end of the elongated ablation
electrode.
14. An irrigation ablation probe according to claim 9, wherein the
elongated ablation electrode remains in a fixed position relative
to the elongated probe body and during operation of the probe.
15. An irrigation ablation probe according to claim 9, wherein the
elongated ablation electrode forms the infusion tube.
16. An irrigation ablation probe according to claim 9, wherein the
elongated ablation electrode is made of stainless steel.
17. An irrigation ablation probe according to claim 9, wherein the
elongated ablation electrode has an inner diameter ranging from
about 0.40 inch to about 0.80 inch and an outer diameter ranging
from about 0.50 inch to about 0.90 inch.
18. An irrigation ablation probe according to claim 9, wherein the
elongated ablation electrode has an outer diameter ranging from
about 0.50 inch to about 0.70 inch.
19. An irrigation ablation probe according to claim 9, wherein the
elongated ablation electrode has an inner diameter ranging from
about 0.40 inch to about 0.60 inch.
20. An irrigation ablation probe according to claim 9, wherein the
elongated ablation electrode is made of a malleable material.
21. An irrigation ablation probe according to claim 13, wherein the
proximal end of the elongated ablation electrode is mounted in the
handle.
22. An irrigation ablation probe according to claim 9, further
comprising a flexible plastic tubing attached to the proximal end
of the elongated ablation electrode for introducing fluid into the
elongated ablation electrode.
23. An irrigation ablation probe according to claim 13, further
comprising a flexible plastic tubing attached to the proximal end
of the elongated ablation electrode within the handle.
24. An irrigation ablation probe according to claim 9, wherein the
at least one irrigation opening is located in the exposed distal
portion of the elongated tubular ablation electrode to be in
contact with the tissue to be ablated.
25. An irrigation ablation probe according to claim 9, wherein the
elongated probe body has a length ranging from about 3.5 inches to
about 12 inches.
26. An irrigation ablation probe according to claim 9, wherein the
elongated probe body has a length ranging from about 5 inches to
about 10 inches.
27. An irrigation ablation probe according to claim 9, wherein the
elongated probe body has a length ranging from about 7 inches to
about 8 inches.
28. An irrigation ablation probe according to claim 9, wherein the
exposed distal portion of the elongated ablation electrode has a
length ranging from about 0.50 inch to about 1.5 inches.
29. An irrigation ablation probe according to claim 9, wherein the
exposed portion of the elongated ablation electrode has a length
ranging from about 0.75 inch to about 1.25 inches.
30. An irrigation ablation probe according to claim 1, wherein the
exposed distal portion of the elongated ablation electrode is
conductive around a full circumference of the exposed distal
portion.
31. An irrigation ablation probe according to claim 9, wherein the
exposed distal portion of the elongated ablation electrode is
conductive around a full circumference of the exposed distal
portion.
32. An irrigation ablation probe according to claim 30, wherein
substantially the entire exposed distal portion of the elongated
ablation electrode is conductive.
33. An irrigation ablation probe according to claim 31, wherein
substantially the entire exposed distal portion of the elongated
ablation electrode is conductive.
34. An irrigation ablation probe according to claim 1, wherein the
angle .alpha. ranges from greater than 0.degree. to about
270.degree..
35. An irrigation ablation probe according to claim 1, wherein the
angle .alpha. ranges from about 60.degree. to about
140.degree..
36. An irrigation ablation probe according to claim 1, wherein the
angle .alpha. is about 90.degree..
37. An irrigation ablation probe according to claim 9, wherein the
angle .alpha. ranges from greater than 0.degree. to about
270.degree..
38. An irrigation ablation probe according to claim 9, wherein the
angle .alpha. ranges from about 60.degree. to about
140.degree..
39. An irrigation ablation probe according to claim 9, wherein the
angle .alpha. is about 90.degree..
40. An irrigation ablation probe according to claim 1, wherein the
at least one irrigation opening is located in the exposed distal
portion of the elongated ablation electrode to be in contract with
the tissue to be ablated.
41. An irrigation ablation probe according to claim 1, wherein a
plurality of irrigation openings are located in the exposed distal
portion of the elongated ablation electrode to be in contact with
the tissue to be ablated.
42. An irrigation ablation probe according to claim 7, wherein the
infusion tube and the elongate ablation electrode comprise a single
generally hollow body.
43. An irrigation ablation probe according to claim 9, wherein the
infuision tube and the elongated ablation electrode comprise a
single generally hollow body.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS(S)
[0001] This patent application is a divisional of U.S. patent
application Ser. No. 09/370,601, filed on Aug. 10, 1999, entitled,
"Irrigation Probe For Ablation During Open Heart Surgery."
FIELD OF THE INVENTION
[0002] The present invention is directed to an irrigation ablation
probe for use during open heart surgery.
BACKGROUND OF THE INVENTION
[0003] Atrial fibrillation is a common sustained cardiac arrhythmia
and a major cause of stroke. This condition is perpetuated by
reentrant wavelets propagating in an abnormal atrial-tissue
substrate. Various approaches have been developed to interrupt
wavelets, including surgical or catheter-mediated atriotomy. It is
believed that to treat atrial fibrillation by radio-frequency
ablation using a catheter, continuous linear lesions must be formed
to segment the heart tissue. By segmenting the heart tissue, no
electrical activity can be transmitted from one segment to another.
Preferably, the segments are made too small to be able to sustain
the fibrillatory process.
[0004] It has been found that over 60% of patients with mitral
valve problems also have atrial fibrillation. Moreover, patients
undergoing open heart surgery commonly develop atrial fibrillation
during the surgery, and thus it would be useful to address this
problem during the surgery. Accordingly, under certain
circumstances it may be desirable to treat atrial fibrillation
during open heart surgery, for example, when a patient is
undergoing a mitral valve replacement or repair procedure.
Accordingly, a need exists for devices and methods for treating
atrial fibrillation during open heart surgery.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to an irrigation ablation
probe for treating atrial fibrillation during open heart surgery.
The probes of the present invention are also useful for other
ablation procedures, particularly where irrigation of the ablation
site is desired, such as for treating ventricular tachycardia. The
invention is also directed to novel methods for treating atrial
fibrillation with the probe of the invention. In accordance with
the present invention, the probe comprises a rigid probe body and
an irrigated ablation electrode, which provides cooling and
irrigation in the region of the tissue being ablated.
[0006] In one embodiment, the invention is directed to an
irrigation ablation probe comprising a generally rigid probe body
having proximal and distal ends. The probe body has an ablation
electrode at its distal end having at least one irrigation opening
through which fluid can pass. An infusion tube having proximal and
distal ends extends through the probe body for introducing fluid
into the ablation electrode.
[0007] In another embodiment, the invention is directed to an
irrigation ablation probe. The probe comprises a generally rigid
probe body and a handle. The probe body has proximal and distal
ends and comprises an ablation electrode at its distal end. The
ablation electrode has at least one irrigation opening through
which fluid can pass. The handle is mounted to the proximal end of
the probe body. An infusion tube having proximal and distal ends
extends through the probe body for introducing fluid into the
ablation electrode. In a particularly preferred embodiment, the
generally rigid probe body comprises a tubular electrode and a
non-conductive sheath covering a portion of the tubular electrode.
In another preferred embodiment, the generally rigid probe body
comprises tubing having proximal and distal ends and at least one
lumen extending therethrough. A tip electrode is mounted at the
distal end of the tubing. The tip electrode has at least one
irrigation opening through which fluid can pass. The probe body
further comprises means for introducing fluid through the
irrigation opening(s) of the tip electrode and a stiffening wire
extending through a lumen of the tubing. A preferred means for
introducing fluid comprises an infusion tube that extends through a
lumen of the tubing with the distal end of the infusion tube in
fluid communication with the one irrigation opening(s) in the tip
electrode.
[0008] In still another embodiment, the invention is directed to an
irrigation ablation probe comprising a generally rigid probe body
and a handle mounted to the proximal end of the probe body. The
probe body has an ablation electrode at its distal end. The
generally rigid probe body comprises a malleable material.
[0009] In yet another embodiment, the invention is directed to a
method for treating atrial fibrillation in a patient. The method
comprises opening the heart of the patient and ablating at least
one linear lesion in the heart tissue using an irrigation probe as
described above.
DESCRIPTION OF THE DRAWINGS
[0010] These and other features and advantages of the present
invention will be better understood by reference to the following
detailed description when considered in conjunction with the
accompanying drawings wherein:
[0011] FIG. 1 is a side view of an embodiment of an irrigation
ablation probe according to the invention.
[0012] FIG. 2 is a side cross-sectional view of the handle of the
irrigation ablation probe of FIG. 1.
[0013] FIG. 3 is a perspective view of the distal end of the
irrigation ablation probe of FIG. 1.
[0014] FIG. 4 is a side view of an alternative embodiment of an
irrigation ablation probe according to the invention.
[0015] FIG. 5 is a side cross-sectional schematic view of the
distal end of the irrigation ablation probe of FIG. 4, wherein the
lumens are not shown to scale.
[0016] FIG. 6 is an end cross-sectional view of the distal end of
the irrigation probe of FIG. 4.
DETAILED DESCRIPTION
[0017] The present invention is directed to an irrigation ablation
probe for use during open heart surgery. In one embodiment, as
shown in FIGS. 1 and 2, the irrigation ablation probe 10 comprises
a probe body 12 mounted to a handle 14. The probe body 12 comprises
a tubular electrode 16, having proximal and distal ends, covered
over a proximal portion of its length by a non-conductive covering
or sheath 18. The tubular electrode 16 extends the entire length of
the probe body 12, the proximal end of the tubular electrode
extending into the handle 14 as described in more detail below. The
probe body 12 preferably has a length (from the distal end of the
handle to the distal end of the probe body) ranging from about 3.5
inches to about 12 inches, more preferably from about 5 to about 10
inches, still more preferably from about 7 to about 8 inches.
[0018] The tubular electrode 16 is made of a material that is
generally rigid so that the probe body 12 cannot bend during
ablation, such as, for example, stainless steel (preferably 304
VSS) or nitinol. Preferably the tubular electrode 16 has an inner
diameter ranging from about 0.40 inch to about 0.80 inch, more
preferably about 0.047 inch, and an outer diameter ranging from
about 0.50 inch to about 0.90 inch, more preferably about 0.059
inch. If desired, the tubular electrode 16 can be heat-treated so
that it is malleable enough to be bent by a physician to a desired
shape but still rigid enough that it will not bend in use during an
ablation procedure. For example, for 304 VSS stainless steel, the
material is heated to about 800 EF with electrical current or in a
salt bath. The hollow interior of the tubular electrode 16 forms a
lumen through which saline and the like may be infused during an
ablation procedure, as described in more detail below.
[0019] The non-conductive sheath 18 extends from a proximal end
inside the handle 14 to a distal end that is longitudinally spaced
apart from the distal end of the tubular electrode 16. In this
arrangement, the distal end of the tubular electrode 16 is exposed,
i.e., not covered by the sheath 18, for ablating tissue. Preferably
the length of the exposed portion of the tubular electrode 16
ranges from about 0.50 inch to about 1.5 inches, more preferably
from about 0.75 inch to about 1.25 inches. The sheath 18 can be
made of any suitable biocompatible non-conductive material, such as
polyurethane.
[0020] In the embodiment depicted in FIGS. 1 to 3, the probe body
12 is bent near its distal ends at an angle .alpha., with the
exposed distal end of the tubular electrode 16 being generally
straight. However, the probe body 12 can alternatively be straight
along its entire length. The angle .alpha. preferably ranges from
about 0 E to about 270 E, more preferably from about 60 E to about
140 E, still more preferably about 90 E. The angle .alpha. depends
on the location of the heart tissue to be ablated. If the tubular
electrode 16 is malleable, the surgeon can bend the probe body 12
to adjust the angle a for a particular procedure.
[0021] In the depicted embodiment, the length of the probe body 12
is approximately 7 inches. The proximal section of the probe body
12, i.e., the portion extending from the handle 14, is
approximately 5.5 inches. The length of the exposed distal portion
of the tubular electrode 16, i.e., the portion not covered by the
sheath 18, is approximately 1 inch.
[0022] As shown in FIG. 3, the exposed distal end of the tubular
electrode 16 has a series of irrigation openings 20 for passage of
a cooling fluid out through the electrode. The irrigation openings
20 can take any suitable shape, such as rectangular or oval slots
or round holes. The irrigation openings 20 are preferably in the
section of the exposed portion of the tubular electrode 16 that is
to be in contact with the tissue during an ablation procedure to
enhance the cooling of the ablation site.
[0023] Saline or other suitable fluid is introduced into the
tubular electrode 16 through a luer hub 22 or the like at the
proximal end of the probe 10. The luer hub 22 is connected to a
flexible plastic tubing 24, e.g., made of polyimide. The plastic
tubing 24 is attached to the proximal end of the tubular electrode
16, preferably within the handle 14, as shown in FIG. 2.
Alternatively, the tubing 24 can be connected to a suction source
(not shown) to permit aspiration of fluid from the region being
ablated.
[0024] As shown in FIG. 2, the handle 14 comprises a housing 26
having a generally open interior 28. The tubular electrode 16 and
sheath 18 extend into the distal end of the handle housing 26. In
the depicted embodiment, the sheath 18 terminates a short distance
proximal to the distal end of the housing 26. The tubular electrode
16 continues proximally beyond the sheath 18. The flexible plastic
tubing 24 extends into the proximal end of the handle housing 26.
The plastic tubing 24 is attached to the tubular electrode 16
within the open interior 28 of the handle, preferably at a point
proximal to the proximal end of the sheath 18. The plastic tubing
24 can be attached to the tubular electrode 16 by any suitable
means, for example, polyurethane glue. By this design, cooling
fluid is introduced through the luer hub 22, though the plastic
tubing 24, through the tubular electrode 16 and out the irrigation
openings 20 in the exposed distal end of the tubular electrode.
[0025] An electrode lead wire 30 having proximal and distal ends is
electrically connected at or adjacent its distal end to the tubular
electrode 16. The proximal end of the lead wire 30 is attached to a
connector 32 for connection to a suitable source of radio frequency
energy. In the depicted embodiment, the lead wire 30 extends into
the proximal end of the handle housing 26. Within the open interior
28 of the handle 14, the distal end of the lead wire 30 is wrapped
around the portion of the tubular electrode 16 not covered by the
sheath 18 and held in place by solder or the like. The portion of
the lead wire 30 that extends outside the handle 14 is covered by a
flexible plastic protective tubing 34, e.g., made of polyimide.
[0026] An alternative embodiment of an irrigation ablation probe
according to the invention is shown in FIGS. 4 to 6. The probe 10
comprises a probe body 12 and a handle 14. The probe body 12
comprises a non-conductive tubing 40 having proximal and distal
ends. In a particularly preferred embodiment, the non-conductive
tubing 40 comprises outer and inner plastic walls, e.g., of
polyurethane or polyimide, surrounding an imbedded braided mesh of
stainless steel or the like. Preferably the tubing has an outer
diameter of less than 8 French, more preferably less than 7 French.
The tubing 40 has three lumens 42, 44 and 46 extending along its
length.
[0027] An irrigated tip electrode 48 is fixedly mounted on the
distal end of the non-conductive tubing 40. Preferably the tip
electrode 48 has a diameter about the same as the outer diameter of
the tubing 40 and an exposed length, i.e., the length extending
outside of the tubing, ranging from about 2 mm to about 10 mm. As
illustrated in FIG. 5, the tip electrode 48 is generally solid,
having a fluid passage 50 and first and second blind holes 52 and
54 that correspond in size and location to the three lumens 46, 42
and 44, respectively, in the non-conductive tubing 40. In the
embodiment shown, the fluid passage 50 comprises a longitudinal
branch 56 and six transverse branches 58 that extend transversely
from near the distal end of the longitudinal branch to the outer
surface of the tip electrode 48. It is understood that the
configuration of the fluid passage 50 may vary as desired. For
example, the fluid passage 50 may form a longitudinal hole that
extends out the distal end of the tip electrode 48 without
transverse branches, or the tip electrode 48 may be porous enough
to allow fluids to pass to the outer surface of the tip electrode,
the interconnecting pores forming the fluid passage. Examples of
suitable porous electrodes for use in the present invention are
described in U.S. Patent Application entitled A porous Irrigated
Tip Electrode Catheter@, by inventors Michele Fung and Shawn
Moaddeb, filed concurrently herewith, the disclosure of which is
incorporated herein by reference.
[0028] The tip electrode 48 can be attached to the non-conductive
tubing 40 in any suitable manner. In the depicted embodiment, the
tip electrode 48 is attached to the tubing 40 by polyurethane glue
or the like. The wires and tubes that extend into the tip electrode
48, discussed more below, help to keep the tip electrode in place
on the tubing 40. However, any other means for fixedly mounting the
tip electrode 48 on the distal end of the tubing 40 can also be
used.
[0029] In the embodiment shown, a mapping ring electrode 62 is
mounted on the tubing 40 proximal to the tip electrode 48. It is
understood that the presence and number of ring electrodes may vary
as desired. The ring electrode 62 is slid over the tubing 40 and
fixed in place by glue or the like.
[0030] The tip electrode 48 and ring electrodes 62 can be made of
any suitable material, and are preferably machined from
platinum-iridium bar (90% platinum/10% iridium).
[0031] The tip electrode 48 and ring electrode 62 are each
connected to a separate lead wire 64. The lead wires 64 extend
through the first lumen 42 of tubing 40 and through the handle 14.
The lead wires 64 terminate at their proximal end in a connector 32
that may be plugged into an appropriate monitor and/or source of
radio frequency energy. The portion of the lead wires 64 extending
out the proximal end of the handle 14 are enclosed within a
protective tubing 34, which can be made of any suitable material,
preferably polyimide.
[0032] The lead wires 64 are attached to the tip electrode 48 and
ring electrode 62 by any conventional technique. Connection of a
lead wire 64 to the tip electrode 48 is accomplished, for example,
by soldering the lead wire 64 into the second blind hole 54 in the
tip electrode.
[0033] Connection of a lead wire 64 to the ring electrode 62 is
preferably accomplished by first making a small hole through the
tubing 40. Such a hole can be created, for example, by inserting a
needle through the tubing 40 and heating the needle sufficiently to
form a permanent hole. A lead wire 64 is then drawn through the
hole by using a microhook or the like. The ends of the lead wire 64
are then stripped of any coating and soldered or welded to the
underside of the ring electrode 62, which is then slid into
position over the hole and fixed in place with polyurethane glue or
the like.
[0034] A temperature sensing means is provided for the tip
electrode 48 and, if desired, the ring electrode 62. Any
conventional temperature sensing means, e.g., a thermocouple or
thermistor, may be used. With reference to FIG. 5, a preferred
temperature sensing means for the tip electrode 48 comprises a
thermocouple formed by a wire pair. One wire of the wire pair is a
copper wire 66, e.g., a number 38 copper wire. The other wire of
the wire pair is a constantan wire 68, which gives support and
strength to the wire pair. The wires 66 and 68 of the wire pair are
electrically isolated from each other except at their distal ends
where they contact and are twisted together, covered with a short
piece of plastic tubing 70, e.g., polyimide, and covered with
epoxy. The plastic tubing 70 is then attached in the first blind
hole 52 of the tip electrode 48 by polyurethane glue or the like.
The wires 66 and 68 extend through the first lumen 42 in the
non-conductive tubing 40. The wires 66 and 68 then extend out
through the handle 14 and to a connector (not shown) connectable to
a temperature monitor (not shown).
[0035] Alternatively, the temperature sensing means may be a
thermistor. A suitable thermistor for use in the present invention
is Model No. AB6N2-GC14KA143E/37C sold by Thermometrics (New
Jersey).
[0036] An infusion tube 72 is provided for infusing fluids, e.g.,
saline, to cool the tip electrode 48. The infusion tube 72 may also
be used to infuse drugs or to collect tissue or fluid samples. The
infusion tube 72 may be made of any suitable material, and is
preferably made of polyimide tubing. The infusion tube 72 has
proximal and distal ends, with its distal end mounted in the fluid
passage 50 of the tip electrode 48 by any suitable method, e.g., by
polyurethane glue or the like. The infusion tube 72 extends from
the tip electrode 48, through the third lumen 46 of the tubing 40,
and through the handle 14. The proximal end of the infuision tube
72 ends in a luer hub 22 or the like.
[0037] A stiffening wire 74, having proximal and distal ends, is
mounted in the second lumen 44 of the tubing 40. The stiffening
wire 74 is made of a rigid metal or plastic material, preferably
stainless steel, to prevent the probe body 12 from bending during
an ablation procedure. If desired, the stiffening wire 74 can be
heat-treated so that it is malleable and can be bent to a desired
shape before use, but still rigid enough that it will not bend in
use during an ablation procedure. A non-conductive tube 76,
preferably made of polyimide, is attached to the distal end of the
stiffening wire 74 for mounting the stiffening wire in the tip
electrode 48. The non-conductive tube 76 extends out of the second
lumen 44 and into the second blind hole 54 in the tip electrode 48,
and is secured in place by polyurethane glue or the like. The
non-conductive tube 76, along with the infusion tube 72, lead wires
64, and thermocouple wires 66 and 68, helps to maintain the tip
electrode 48 in place on the tubing 40. As would be recognized by
one skilled in the art, the stiffening wire 74 could be mounted in
any other suitable way so long as the stiffening wire, if made of
metal, is not in electrical connection with the tip electrode 46.
The proximal end of the stiffening wire 74 terminates in the handle
14 or near the proximal end of the probe body 12.
[0038] The tip electrode 48 is then used to form continuous linear
lesions by ablation. As used herein, a linear lesion refers to any
lesion, whether curved or straight, between two anatomical
structures in the heart that is sufficient to block a wavelet,
i.e., forms a boundary for the wavelet. Anatomical structures,
referred to as Aatrial trigger spots@, are those regions in the
heart having limited or no electrical conductivity and are
described in Haissaguerre et al., ASpontaneous Initiation of Atrial
Fibrillation by Ectopic Beats Originating in the Pulmonary Veins@,
New England Journal of Medicine, 339:659-666 (Sep. 3, 1998), the
disclosure of which is incorporated herein by reference. The linear
lesions typically have a length of from about 1 cm to about 4 cm,
but can be longer or shorter as necessary for a particular
procedure.
[0039] The above described probes are for use during open heart
surgery. During a procedure, the heart is opened and the irrigated
electrode is used to form continuous linear lesions by ablation. As
used herein, a linear lesion refers to any lesion, whether curved
or straight, between two anatomical structures in the heart that is
sufficient to block a wavelet, i.e., forms a boundary for the
wavelet. Anatomical structures, referred to as Aatrial trigger
spots@, are those regions in the heart having limited or no
electrical conductivity and are described in Haissaguerre et al.,
ASpontaneous Initiation of Atrial Fibrillation by Ectopic Beats
Originating in the Pulmonary Veins@, New England Journal of
Medicine, 339:659-666 (Sep. 3, 1998), the disclosure of which is
incorporated herein by reference. The linear lesions typically have
a length of from about 1 cm to about 4 cm, but can be longer or
shorter as necessary for a particular procedure. The
above-described probe having a long tubular electrode is
particularly useful for this procedure because it can create
relatively long lesions. The probe depicted in FIGS. 4 to 6 above,
having a smaller ablation electrode, is useful if the surgeon does
not want to ablate as much tissue or wants to ablate a more precise
lesion. The above-described probe having a malleable body is
particularly useful if the surgeon needs to bend the probe to
better ablate a desired region of tissue. Once the heart is closed,
the surgeon can use the probe depicted in FIGS. 4 to 6, above, on
the outside of the heart, not only to ablate, but to verify that
the electrical conduction has been stopped using the mapping
electrodes. As would be recognized by one skilled in the art, the
probes of the present invention can be used during open heart
surgery for other ablation procedures as well.
[0040] The preceding description has been presented with reference
to presently preferred embodiments of the invention. Workers
skilled in the art and technology to which this invention pertains
will appreciate that alterations and changes in the described
structure may be practiced without meaningfully departing from the
principal, spirit and scope of this invention.
[0041] Accordingly, the foregoing description should not be read as
pertaining only to the precise structures described and illustrated
in the accompanying drawings, but rather should be read consistent
with and as support to the following claims which are to have their
fullest and fair scope.
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