CA2435477A1 - Atrial ablation catheter and method for treating atrial fibrillation - Google Patents
Atrial ablation catheter and method for treating atrial fibrillation Download PDFInfo
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- CA2435477A1 CA2435477A1 CA002435477A CA2435477A CA2435477A1 CA 2435477 A1 CA2435477 A1 CA 2435477A1 CA 002435477 A CA002435477 A CA 002435477A CA 2435477 A CA2435477 A CA 2435477A CA 2435477 A1 CA2435477 A1 CA 2435477A1
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
- A61B18/04—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating
- A61B18/12—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body by heating by passing a current through the tissue to be heated, e.g. high-frequency current
- A61B18/14—Probes or electrodes therefor
- A61B18/1492—Probes or electrodes therefor having a flexible, catheter-like structure, e.g. for heart ablation
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B2017/00831—Material properties
- A61B2017/00867—Material properties shape memory effect
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
- A61B2018/00315—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body for treatment of particular body parts
- A61B2018/00345—Vascular system
- A61B2018/00351—Heart
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B18/00—Surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
- A61B2018/00636—Sensing and controlling the application of energy
- A61B2018/00773—Sensed parameters
- A61B2018/00791—Temperature
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B34/00—Computer-aided surgery; Manipulators or robots specially adapted for use in surgery
- A61B34/20—Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
- A61B2034/2046—Tracking techniques
- A61B2034/2051—Electromagnetic tracking systems
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B2218/00—Details of surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body
- A61B2218/001—Details of surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body having means for irrigation and/or aspiration of substances to and/or from the surgical site
- A61B2218/002—Irrigation
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2201/00—Properties
- C08L2201/12—Shape memory
Abstract
A catheter for ablating tissue is provided. The catheter comprises an elongated generally tubular catheter body having proximal and distal ends and at least one lumen extending therethrough. A non-retractable ablation assembly is attached to the distal end of the catheter body. The ablation assembly comprises proximal and distal non-conductive tubings, each having a lumen extending therethrough and a generally tubular electrode mounted between the proximal and distal non-conductive tubings. The tubular electrode is formed of a material having shape-memory and has at least one irrigation port through which fluid can pass from the inside to the outside of the electrode. The ablation assembly further comprises a non-conductive protective tubing extending generally parallel to and along the outside of the tubular electrode. The protective tubing has proximal arid distal ends extending into the proximal and distal non-conductive tubings, respectively. The catheter fiber comprises at least one of an electrode lead wire and a temperature sensor wire, and preferably both, extending through the non-conductive protective tubing and catheter body, the electrode lead wire having a distal end mounted to a ring electrode mounted on the distal non-conductive tubing, and the temperature sensor wire having a distal end mounted on or under the distal non-conductive tubing. The catheter also comprises an infusion tube extending through the catheter body and having a distal end in fluid communication with the proximal end of the tubular electrode.
Description
ATRIAL ~~A~~N C.f~T~TF.rR Altls 1 METHOD FOR TREATING AT'RIAI~ FISRILLATI01~1 F>EL,D OF THE INVENTION
The present invention relates to an improved steerable electrode catheter having au irrigated ablation electrode that is particularly useful for treating atrial ~abrillation.
BACKGROUND OF THE INVENTION
Attial ~brillation is a com~tnon sustained cardiac arrhythmia and a rna,~or cause of stroke. This condition is perpetuated byreentrant wavelets propagating in an abnarmal atrial-1 ~ tissue substrate. Various approaches have been developexl to interrupt wavelets, including surgical or catheter-mediated atriotomy. It is believed that to treat atrial fibrillation by radio-frequency ablation using a catheter, coatinuaus linear lesions must be formed to segment the heart tissue. By seg~n.enting tlac heart tissue, no electrical activity can be transmitted from one segment to another. Preferably, the segments are made trao small to be able to sustain the 1 ~ fibrillatory process. A preferred technique for treating atrial fibrillation by radio-frequency ablation would be a "branding iron" approach, where a relatively iong electrode can be held stationary in good contact with the heart wall while ablation is completed. In this way, a continuous transmural burn may be effected.
U.8. Patent No. 5,80,428 to Nelson et al. discloses a radia frequency ablation ~ catheter system having a flexible, tubular electrode for creating a continuous linear lesion.
The tubular electrode as selectively extendable from the distal end of the catheter. The catheter f~tu~ther comprises axechanistns for remotely manipulating and extending the electrode. However, having an extendable electrode house in the catheter provides less degrees of freedom with respect to the shape, size and leng~ of the tubular electrode.
25 M°~o~, ~e physician has to deal with additional. moving and rnatuipulatable parts, adding complexity to the procedure. Further, a retractable electrode can cause contamination because blood or coagulate on the electrode can he pulled into a~ad entrapped inside the catheter. The entrapped coage~..late can also affect the ability of the electrode to be further extended and retracted. Accordingly, it would be desirable to provide a catheter design having an electrode for creating linear lesions that overcomes these drawbacks.
_I.
SLJwIMARY OF THE INVENTION
1 The invention is directed to an improved catheter for ablating tissue. The catheter comprises an elongated generally-tubular catheter body having proximal and distal ends and at least one lumen extending therethrough. A non-retractable. ablation assembly is attached to the clistal. end of the catheter body. The ablation assembly wmprises proximal and distal non-conductive tubings, each having a lumen extending th~xethrough, and a generally tubular electrode mounted between the proximal and distal z~on ~c~ndtxctive tubings.
The tubular electrode is formed of a material having shape-memory and has at least oxae irrigation port through which .fluid can pass from the inside to the outside of the electrode.
The ablation assembly further comprises a non-conductive protective tubing extending generally parallel to 1~ and along the outside of the tubular electrode that has proxunal and distal ends extending into the proximal and distal non-conductive tubings, respectively. The catheter futxher comprises at least one of an electrode lead wire and a temperature sensor wire, and preferably both, extending through the nort-conductive protective tubing and catheter body. Ths electrode lead wire has a distal end mounted to a ring electrode mounted on thedistal non-conductive tubing. Th~
1$ temperature sensor ~avire has a distal end mounted on or under the distal non-conductive tubing.
The catheter also includes means for introducing fluid into the tubular electrode.
In another embodiment, the invention is directed to a catheter for ablating tissue comprising a catheter body having an outer wall, proximal and distal ends, and at least one lumen extending theretluough. An intermediate section comprising a segment of flexible tubing having ~ proximal and distal ends and at least one lumen therethroulh is fixedly attached at its proximal end to the distal end of the catheter body. A non-retractable ablation assetxtbly as described above is attached to the distal end of the intermediate section, An infusion tube extends through a lumen in the intermediate sactivn and has a distal end in fluid communication with the proximal end of the tubular electrode.
25 ~ ~o'~er embodiment, the invention is directedl to a method for treating atrfal fbrjllatfon. The method comprises inserting the distal end of a catheter as described above into an atria of the heart, and formfag at least one linear lesion fn the atrfal tissue with the tnbnlar electrode.
_2-In yet another embodiment, the invention ~ dimeeted to a method fgr treating atrial fibrillation comprising providing a catheter as described above and a guiding sheath having proximal and distal ends. The guiding sheath is inserted into the body so that the distal end of the grading sheath is in an atria of the heart. The catheter is inserted into the proximal end of the guiding sheath and fed through the guiding sheath so that the distal end of the catheter extends out the distal end of the guiding sheath. The method further comprises formfng at least one Ifnear lesion in the atrial tissue with the tubular electrc'de.
laEgCRInTION' OF 'THE DRF~WI1~TGS
These and other features and advantages of the present invention will be better understood by reference to the following detailed description when ~conszdered in conjunction with the accompanying drawings wherein;:
FIG, 1 is a side cross-sectional view of an embodiment of the catheter of the invention.
FIG. 2 is a side cross~sectiona'lwiew of a catheter body according to the invention, including the junction between the catheter body and interrraediate section.
FICA. 3A is ;~ side cross-sectional ~~iew of the proximal end of a tubular ablation assembly according to the invention.
FIG. 3E is a side cross-sectional vievcr of the distal end of the.tubular ablation assembly of FIG. 3~1"
FIG. 4 is an end cross-sectional view of the tubular ablation assembly of FIG.
3A along line 4-4.
FIGS. 5A and SB axe perspective views of an alternate tubular ablation assembly according to the invention.
FIG. 6 is a side cross-sectional view of the distal end of an alternate tubular ablation assembly according to the invention.
25 FIG. 7 is~ a cross sectional view of a portion of tl~e catheter intezmediate section showing one means for attaching the pulley wire.
FIG. 8 is a top cross sectional views of a preferred prxller wire anchor.
FzG. 9 is a side cross sectional views of the pullet wire anchor of FIG.' 8 0 FIG.10 is a side cross-sectional view of the distal end of tb,e tubular ablation assembly of 30 ~ Steve embodiment including a location sensor.
DETAILED DBSCRIPTION
,3_ 1n a particularly preferred embodiment of the invention there is provided a steerable 1 catheter having an irrigated tubular ablation electrode. As shown in FZG 1, catheter 10 comprises an elongated catheter body 12 having proximal and distal ends, an intermediate section 14 at the distal end of the catheter body, an ablation assembly IS mounted at the distal end of the intermediate section, and a control handle 1, 6 at the proximal end of the catheter body.
With reference to 11'IG. 2, the catheter body 12 comprises an elongated tubular construction having a single, axial or central lumen 18, The catheter body >l2 is flexible, i.e., bendable, but substantially noh.-compressible along its length. The catheter body 12 can be of any suitable construction and made of any suitable material.. A presently preferred construction comprises as outer wall 22 made of polyurethane or PEBAX. 'The outer wall 22 comprises an imbedded braided mesh of stainless steel or the lilts to increase torsional sti#Tness of the catheter body iz so that, when the control handle 16 is rotated, the intermediate section 14 of the catheter 10 will rotate in a corresponding manner.
The outer diameter of the catheter body 12 is not critical, but is preferably no more than about 8 ftench, more preferably 7 french. f,ikewise the thickness of the outer wall 22 is net 1 ~ critical, bt~t is thin ;,rough so :hat the central lumen 1S can accommodate an infusion tube, a puller wire, lead wires, and any other wires, cables or tubes, If desired, the inner surface of the outer wall 22 is lined with a stiffening tube (not shown) to provade improved torsional stability.
A particularly preferred catheter has an outer wall 22 wirb: an outer diameter of from about 0.090 inch to about 0.94 inch and an izaner diameter of from about: 0.061 inch to about 0.065 inch.
Iu the depicted embodiment, the intermediate section 14 comprises a shoat section of tubing 19 having three lumens. The frat lumen 30 electrode carries lead wires S0, the second lumen 32 carries a pulley wire 64, and the third lumen 34 carries an infusion tube 44. The wires and tube are described iri more detail below. 'The tubing 1.9 is made of a suztable non-toxic material that is preferably more i~exible than the catheter body 12. ~, presentlypreferred material for the tubing 19 is braided polyurethane, i.e., polyurethane with an embedded mesh of braided stainless steel or the like, that is more flexible than the catheter body, Tile number atld size of the lumens as not critical and can vary dependinn on the various,w~ires, tubes and other components carried by the catheter, In a preferred embodiment, the intermediate section 14 has an outer diameter ranging from about 5 French {.066 inch) to 8 French {.105 inch), and the first lumen 30 and accord lumen 32 are generally about the same size, each having a diameter of from about 0.020 inch to about 0.024 inch, preferably 0.022 inch, with the third lumen 34 having a slightly larger diameter of from about 0.032 inch to about 0.038 inch, preferably 0.035 inch.
A preferred means for attaching then catheter body 12 to the intermediate section 14 is illustrated in IETG. 2. The proximal end of the intermedla~te section ~,4 comprises an outer circumferential notch Z4 that receives the inner surface of the outex wall 22 of the catheter 1 body 12. The intermediate section 14 and catheter body 12 are attached by glue or the like.
If desired, a spacer (not showtl) cats be located within the catheter body at its distal end, adjacent the proximal end of the zntennediate section. The spacer provides a transition in, flexibility at fhe junction of the catheter body and ixltermediate section, which allows this junction to bend smoothly without folding ox kicking. A catheter having such a spacer is described in U.S. Patent No. 5,964,75, the disclosure of which is incorporated herein.by reference.
At the distal end of the intermediate. section 1 A is a non-retractable ablation assembly 15, as shown in FIGs. l, 3A, 3B and 4. In the depicted embodiment, the ablation assembly 15 has proximal and distal ends and comprises a tubular electrode 38 between a non-conductive distal segment 40 and a non-conductive proximal segment 42, all described further below.
The ablation assembly 15 is shaped so that it is beat relative to the straight tubing 19 of the intermediate section 14.. As used herein, the team "Gent" when used to describe the ablation assembly 15 is intended to mean that the assembly is carved, bent or angled to any extent at any point along its leng~.. With this design, when a physician. deflects the intermediate section 14, the tubular electrode 3H is pressed against the tissue, creatit~,g a "branding imn" effect. In contrast, a physician using a straight catheter having one or more electrodes along the length of its distal end to create a linear lesion wall find it difficult to provide the same amount of pressure on the tissue with the electrode(s). The particular shape of the ablation assembly 15 depends on the desired application, i.e., the precise lacauon in the atrium, or elsewhere at which the catheter is to be used, and for example, can be bent in a single pleas or in multiple planes.
In one embodiment, as shown in FIG. 1, the tubular ablation assembly 15 is generally L-shaped and lies in a single plane. The proximal end of the assembly 1S is generally straight cad collinear with the tubin19 of the intermediate section 14. 2'he assennbly 15 bends at a point along its length. Preferably the straight proximal end of the assembly 15 is sufficiently long to mount one or more mapping rang electrodes, as described in more detail below.
At~er the bend, the distal end of the assembly 15 is generally stxaight. 'The exposed poztion of the tubular electrode 38, i.e., the portion that is not covered by any non~.conductive tubing, is generally L-shaped, but alternatively could be generally straight or one of a variety of other shapes, such as fat described below. T'he non-conductive distal segment 40 is generally collinear with the distal end of the tubular electrode 38, The ablation assembly 15 of this embodiment is preferably shaped so that it forn.~s an .angle a ranging from about 60 degrees to about 140 de;rees. This design is particularly useful for ablation in the open region of the heart.
In ate alternative e~tnbodin~ent, shown in FIGs. 5A and 5B, the ablation assembly 1S is gently lasso-shaped, The proximal end of the assembly 15 is generally collinear with the tubing I9 of the intermediate section I4. The a'ssernbl~ IS cuz~es at its distal end to form a slanted semi-circle, i.e., lying in more than one plane, as best shown in ~'I~. 5B. In this embodiment, the tubular electrode 38 is generally curved. 'This design is particularly useful for ablation in or around a blood vessel, such as the pulmonary vein. As would be recognized by one skilled iti the art, other shapes can be provided for the electrode assembly 15. For example, in the embodiment of FIG. 5B, the tubular electrode 38 forms a full cizcle.
A,s used herein, the term "tubular electrode" refers not only to traditional tubular, i.e., cylindrically-shaped, structures having a hollow interior, but also to any other elongated, generrally-hollow bodies having, for example, au ovular, square, or other geometricaPly shaped cross-sectional. Other shapes will be apparent to those skilled in the art to achieve the purpose described further herein.. Preferably the tubular electrode 38 has an izmer diaxaeter ranging from about 0.018 inch to about 0,024 inch and an outer diameter ranging from about 0.020 inch to about 0.028 inch. 'The length, of the exposed portion of the tubular electrode 38 eau vary depeadiug ca the desired length of the lesion to be created, and preferably ranges from about 8 mm to about 2 cm, more preferably from about 1.2 cna to about I.~ em, to create arelatively long 1 S lesion.
The tubular electrode 38. is made of a material ha ing shape-memory, i.e., that can be straightened or beat ant of its original shape upon exertion of a force and is capable of substantiallyreturning to its original shape upon removal ofthe force.
,kparticularPypreferred material for the tubular electrode is a nickeUtitanium alloy. Such aPloys typically comprise about 55% nickel and 45% titanium, but xriay comprise frown about 54% to about S7%
nickel with the balance being tita~c~ium. A~preferred nickelltitariium alloy is nitinol, which has excellent shape memory, together with ductility, strength, corrosion resistance, electrical resistivity and temperatcue stability. A particularly preferred material is nitiztol fogm from 50.8 atomic% nickel, with the balance titanium:, having an austenite fish and a transition temperature from about 2S +5°C to about -25°C, which is coxrmiercially available from I~itinol Device Corp. (Fremont,, California).
T"he tubular electrode 3~ contains a series of irrigation ports 39 through which fluid can pass during an ablation procedure. Preferably the irrigation ports 39 axe located only an the side of the tubular electrode 38 that is to be in contact with the tissue to be ablated. The irrigation ~0. ports 39 caw be any suitable shape, such as rectangular or ovular slots or round holes. 1'n~ the embodiment shown in FIGs. l, 3 atRd 4, the tubular electrode 38 has six irrigation ports 39, each forming a slot or ellipse with a length preferably ranging from about 0.018 inch to about 0.020 inch. Preferably the irrigation p~rts 3~ are spaced apart from each ofher a distance o~about 0.125 ixxch. Having a limited number of irrigation ports 39 on the side of the tubular electrode 38 35 m ~nt~t with the tissue to be ablated allows for mare even fluid flow out of the electrode. As would be recognized by one s~lled in the art, the precise nau~nber, size, shape said arrang~ent of 1 irrigation poxts 39 can, vary as desired.
An electrode lead wire 50 is attached to the tubular ~;,lectrode 38 for electrical connection to a suitable corurtectar (not shown), which is attached to a source of energy (not shown). In the depicted ernbodimertt, the electrode lead wire 50 is wrapped around the proximal end of the tubular electrode 3~ and soldered, welded or othe~ise attt~ched to the electrode. 'The electrode lead wire SO for the tubular electrode 38 extends through t~~e fret lumen 30 of the intermediate section 14, through the central lumen 18 of the cathete}r body 3.2, and through the eon~°ol handle 16, and are connected tai a suitable source of ablation energy (not shown) by means of an appropriate connector as is generally k~xown in the art.
10' The distal and proximal non-conductive segtnenfis 4~and 42 of the ablation assenxbly 15 comprise distal and proximal non-conductive cov gs 41 and 43, respectively, which ~
preferably made of polyimide or other biocoxpapatible plastic. The distal non-conductive covering 41 extends over the distal end of the tubular ellectrode 38, and the proximal non-conductive covering 43 extends over the proximal end of the tubular electrode.
15 ~ the depi;,i~:d cmmbodiment, two distal rinn electrodes 47 are mounted on the distal non-conductive covering 41, and tvvo proximal rind electrodes 4~8 axe tmounted on the proximal non-conductive covering 43. The ring electrodes 47 and 48 can be made ofany suitable material, and are preferably made of platinum or platinum and iridiuan. Each z~,g electrode cast be mounted by any suitable technique, and is preferably mounted by first fbrming a hole ixx the non-conductive ~ covering. An electrode lead wire 50 is fed through the hole, and the ring electrode is welded ~
place over the lead wire and non-conductive covering. The presence and number of ring electrodes can vary as desired.
Additionally, one or more temperature sensing cleans are pxovided for the tubular electrode 38. Any conventional temperature sensing mean,., e.g., a thermocouple or thermistor, 25 may be used. In the depicted embodiment, two thermocouples az°e provided, each of which is formed by a wire pair. ~ne wire of the wire paax is a copper wire, e.g., a number 38 copper wire, and the other wire of the wire pair is a congtantat~ vviz°e, which gives support and strength to the wire pan. Specifically, a distal thermocouple 45 is pro~rided for measurement distal to the exposed portion of the tubular electrode 38, and a proximal thermocouple 46 is provided for 30 measurement proximal to the exposed portion of the tubuhur electrode. Each thermocouple 4S
and 46 is preferably mounted to a corresponding ring electrode 47 and 48, as shown in FIC'as. 3A
and 3B, by weld, solder or other suitable method. The placement of the thermocouples in the depicted embodiment is particularly desirable because they are located out of the irrigation zone, i.e., the region in which the irrigation fluid primarily flows firom the tubular elects ode 38 through 35 the inigation ports 39. The presence of the fluid can reduce the accuracy of the tissue _7_ temperature measurements by the thermocouples. Accordingly, it is desirable to place the 1 thermocouples or other temperature sensing means as close as possible to the tubular electrode 38 while outside the irrigation zone.
In the depicted embodiment, a non-conductive protective sheath. 52 is provided along the outside of the tubular electrode 38 for carrying the distal thermocouple wires 45 and electrode lead wires 50 connected to the distal ring electrodes 47, The protective sheath 5z extends generally parallel to the tubular electrode 38 and is preferably attached tQ
the tubular electrode along the entire exposed portion of the tubular electrode. '1~he protective sheath 52 is preferably made of polyurethane or polyimide or other suitable bi,ocompatible plastic. rn a preferred embodiment, the protective sheath 52 is glued to the tubular electrode 3S with an adhesive such ~ y CTluse~ and tied in plane using a monoftlament or the like. The tubular electrode 3S and protective sh~ath 52 are then covered with a polyurethane glue or the like, with care beitag taken not to cover the irrigation ports 38, and the monofilament is removed after the polyurethane glue cures. The proximal and distal ends of the protective sheath, 52 extend into the proximal and distal non-conductive coverings 43 and 41. Alternatively, the distal electrode lead wires 50 and ~s~ ~~ocouple was 45 care extend through the tubular electrode 38, although such wires can adversely affect the flow of irrigation fluid through the tubular electrode.
All of the electrode lead wires 50 and therrnoeouple wires 45 and 46 extend through the first lumen 30 in the intermediate seotiox~ 14. Within the catheter body 12, the wires 45, 46 and 50 extend through a protective tubix~n 36 to keep the wires from contacting ~ther components Mending through the central lumen 18. The protective tubing 36 is preferably anchored at its distal end to the proximal end of the intermediate section 14 by gluing it in the dust lumen 30 with polyurethane glue or the like. The electrode lead wires 5C~ them extend out through the control handle 16 an"d to a suitable monitoring device or source of ablation energy (not shown), as appropriate, via a suitable connector (z~ow shown), as is generally known in the an. The ~~°couple wires 45 and 46 similarly extend out through the control handle 16 and to a connector (not shown) connectable to a temperature monitor (not shown).
The distal end of the ablati~n assembly 15 is preferably provided with an atraumatic construction to prevent the distal end of the tubular electrode 38 from penetrating tissue. In the depicted embodiment, the atraumatie construction comprises a tightly wound coil spring 56 m~e~ for example, of stainless steel, such as the mini guidewire commercially available from Cordis corporation (Nl~ami, Florida). The coil sprig 56 is'. mounted within the dzstal arid of the distal non-conductive covering 41 and held in place at its prr~ximal and distal ends with polyurethane glue 6d or the like. in the depicted embodiment, the coil spring 56 has a length of about 0.50 inch, hut can be any desired length for example, ranging from about 0.25 inch to bout 1.0 inch, The coil spring 56 is preferably sufficiently long to serve as an anchor for _g_ introducing the catheter into a buidinc sheath, particularly when the tubular electrode is curved 1 and must be straightened upon introduction into the sheath. 'W'ithout having the coil spring 56 as an anchor, the tubular electrode 38 has a tendency to pull out of the guiding sheath upon its introduction into the guiding sheath. Additionally, if desired, the coil spring 56 can be formed, at least in part, of a radiopaque material to aid in the positioning of the tubular electrode 38 under fluoroscopy.
The coil spring 56 is preferably secured to the distal end of the catheter with a safety wire 54. The distal end of the safety wire S4 is hooked around the coil spring 56 and glued in place, The safety wire 54 extends through the tubular electrode 38 and its proximal end is wrapped around the proximal end of. the tubular electrode and optionally soldered, glued or °~~'ise attached in place. The proximal end of the safety wire 54 can be secured to the catheter in any other suitable manner. For example, i~n an alternative embodiment, (not shown the safety wire can extend through the protective sheath 42 and through the catheter body I2 and be anchored within the control handle 16.
Tile distal non-conductive segment 40 can have any other suitable atraumatic construction fat pt'°tects the tubular electrode 38 from puncturing tl~e heart tissue. An example of an alternative atraumatic construction, as shown ire FIG, 6, is i:c the form ofa ball. To form the ball, the distal end of the distal non-conductive covering 41 is covered with a shoat length of thick non-conductive tubing 58, made of polyimide, polyur~rthane. ox the, like.
Polyurethane adhesive 60 or the like is applied into and around the edges of the non-conductive tubing 58 to round off the. edges of the distal end of the distal non-conductive segment 40.
A pulle2~ wire 64 is provided for deflection of the interm~iate section 14:
The pullet wire 64 extends through the catheter body 12, is anchored at its proximal end to the control handle 16, and is anchored at its distal ennd to the intermediate section 14.
The pullet wire 64 is made of at~y suitable metal, such as stainless steel or Nitinol, aad is preferably coated with Teflon~ or the like. The coating .imparts lubricity to the pullet wire 64. The pullet wire 64 preferably has a diameter ranging from about 0.006 to about 0.010 inch.
A compression coil 66 is situated within the catheter.body 12 in surrounding relation tv the pullet wire 64. The compression coil 66 extends from tho proximal end of the catheter body 12 to the proximal end ofthe intermediate section 14. The compression coil 66 is made of ~y ~~ble metal, preferably stainless steel. The compression coil 66 is tightly wound on itself to provide flexibility, i.e., bending, but to resist eompr~essaou, The inner diameter of the compression coil 66 is preferably slightly larger than the diameter of the pullet ~wire 64. The Teflon~ coating on the pullet wire 64 allo~srs it to slide freely within the compression coil 6G. If desired, particularly if the lead wires 50 are not enclosed 'by a protective tubing 36, the outer s~~e of the compression coil 66 is covered by a flexibl~, non-oox~ductive sheath 68, e.g., made of polyimide tubing, to prevent contact between the compression coil and any other wires within the catheter body 12.
The compression coil 66 is anchored at its proxitxtal end to the outer wail 22 of the catlzetex body 12 by proximal glue joint 70 and at its distal'. end to the intermediate section 14 by distal glue joint 72. Both glue joints 7~ and 72 preferably comprise polyurethane glue or the like.
The glue may be applied by means of a syringe or the like through a hole made between the outer surface of the catheter body 12 arid the central lumen 18. such a hole may be formed, for example, by a needle or the like that punctures the outer wall 22 of the catheter body 12 which is heated sufficiently to form a permanent hole. The glue is then ~t~°oduced through the hole to the outer surface of the compression coil 66 and wicks around the outer circumference to form a glue 1 ~ ,point about the entire circumference of the compression coil 66.
The pulley wire 64 extends into the second lumen 32 of the intermediate section 14.
preferably the pulley ware 64 is anchored at its distal extd to the side of the inteFmediate section 14, as shown in FTGs. 7 to 9. T-shaped anchor 78 is formed which comprises a short piece of tubular stainless steel 80, e.g., ~hypodern~i.c stock,. which is fitted over the distal end of 15 ~e paler v~''~ ~ aid cnmped to ~~xedly secure it to the pulley wire. The distal end of the tubular stainless steel SO is fixedly attached, e.g., by welding, to a stainless steel cross-piece 82 such as stainless steel ribbon or the like. The cross-piece 82 sits in a notch 84 in a wall of the flexible tubing 19 that extends into the second Lumen 32 of the intermediate section 14. The stainless steel cross-piece S2 is larger than the opening and, therefore, cannot be pulled through the opening. The portion ofthe notch 84 not filled bythe cross-piece S2 is filled with ,glue S6 or the like, preferably a polyurethane glue, which is harder than. the material of the flexible tubing i9. Rough edges, if any, of the crass-piece 82 are polished to provide a smooth, continuous surface with the outer surface ofthe.flexible tul9ing 19. Within the second lumen 32 of the intermediate section 14, the pulley wire 64 extends through a plastic, preferably Teflon, 25 pulley wire sheath 74, which prevents the pulley wire 64 from. cutting' into the wall of the intermediate section 14 when the intermediate section is deflected. Any other suitable technique for anchoring the pulley wire 64 in the intermediate section 14 can also be used.
Longitudinal movement of the pullet wire 42 relative to the catheter body I2, which results in deflection of the intermediate section 14, is accomplished by suitable maxtipulation of the control handle 16. Examples of suitable control handles for use in the present invention are disclosed, for example, in U.S. latent I~~s. Re 34,502 anti S,S97,5Z9, the entire disclosures of which are incorporated herein by~ reference.
Within the third lumen 34 of tho intermediate section 14 is provided an infusion tube 44 for infusing fluids, e.g., saline, to cool the tubular electrode 3g ~.d surrounding tissue during ablation. The infusion tube 44 extends through the third lumen 34 of the intermediate section 14, _1~_ through the catheter body 12, out the proximal end of the control handle 16, and ternninates in a 1 luer hub 7d or the like at a location proximal to the control handle. In an alternative azrangement, a single lumen side arm (not shown) is fluidly connected to the central Imnen 18 near the proximal end of the catheter body 1Z, as described in more; detail in LT.S.
Patent No. 6,120,476, the entire disclosure of which is incorporated herein by reference.
Alternatively, the infusion tube 44 can terminate within the distal end of tho third lumien 34 of the intermediate section 14, with a second infusion tube provided that extends from the proximal end of the third lumen, through the catheter body 12 and out through the contrcel handle 16. Such a design is also described in more detail in LT.S. Patent No. 6,120,476. As shown In FIG. 3, the distal end of the you tube 44 extends over the proximal end of the tubular electrode 38, including the Iead ~e 50 and safety wire 54 wrapped around the tubular electrode. '1"he iatfusion tube 44 is attached to the tubular electrode 38 with polyurethane glue or the like, which also acts to seal. the third lumen 34 so that ffuid$ cannot pass into or out of the third lumen other than through the infusion tube and tubular electrode.
In use, a suitable guiding sheath is inserted into the patient. An example of a suitable guiding sheath for use in connection with the present invention is the Preface's Braiding Guiding Sheath, commercially available from C:ordis Webster (Diatxwnd Bar, California). The distal end of the sheath is guided into one of the atria. A catheter in accordance vcrtith the present invention is fed through the guiding sheath until its distal end extends out of the distal etad ofthe guiding sheath.. As the catheter is fEd through the guiding sheath, the tubular electrode 38 can be 0 ~ straightened to fit through tJ~e sheath, and it will return to its original chap a upon removal of fibs sheath.
The tubular electrode 38 is then used to form continuous linear lesions by ablation. .t~s 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 ~e wavelet. Anatomical structures, referred to as "atrial trigger spots", are those regions in the heart having limited or no electrical conductivity and are described ~
Haassaguerre et al., "Spontaneous Initiation 'of Atrial Fibrillation by Ectopic a3eats C3riginating in the Pulmonary veins", New Eland Journal of Medicine, 339:659-666 (Sept. 3,1998), the disclosure ofwhich is incorporated herein by reference. The linear lesions typically have a length of from about 1 ~ to about 4 cm, but can b~ longer or shorter as necessary for a particular procedure, The thermocouples or other temperature sensing means can be used to rttonitor the temperature of the tissue during ablation.
Iu an alternative embodiment, as shown m FIG. 1 i3, the ablation assembly 15 further includes a location sensor 61 for providing IaGation infornr~ation about the ablation assembly.
fly ~e~location sensor 61 comprises a magnetic-field responsive coil, as described in U.S.
-11~
Fatent No. 5,391,199, or a plurality of such coils, as described in International Publication 1 WO 9f!~5758, The plurality of coils enables six-dnmensional position and orientation coordinates to be deter~ned. Alternatively, any sultable position Sensor kctowmn the art may be used, such as electrical, magnetic or acoustic sensors. Suitable location sensors for use with the present invention are also described, for example, in U.S. Patent Nos.
5,558,091, 5,443,489, 5,480,422, 5,546,951, ~ and 5,548,809, and International Publication Nos. WO
95!02995, WO 97/24983, and WO 98/29033, the disclosures ofwhich are incozporatedhereinbyreference.
In the depicted embodiment, the location sensor Gl. is ncaounted in the non-conductive distal segment 40 within the distal .non-conductive covering 41, distal. to the distal end of the tubular electrode 38 and proximal to the proximal end of the coil spring ~6. ~
accordance with 10. the invexttion, the location sensor 61 could be mounted at other positions within the ablation assembly 13 depending on the precise position on the assembly to be located duxing a procedure.
The location sensor 56 is connected to a sensor cable 62 that extends through the protective sheath 52, the catheter body 12 and control handle 16 and ot~t the proximal end of the control handle within an umbilical cord (not shown) to a sensor control module (not shown) that houses a .
15 circuit board (not shown). Alternatively, the circuit board can be housed within the control handle x6, for example, as described in U.S. Patent No. &,Q24,?39, the disclosure of which is incorporated. herein by reference. The sensor cable 62 comprises multiple wires encased within a plastic covexed sheath. 1n the sensor control xriodule, the wires of the sensor cable are connected to the circuit boaxd. The eirca~it board amplifies the signal received from the corresponding 20 location sensor and transmits it to a computer in a form understandable by the computer by means of the sensor connector at the proximal end of the sensor control module. Also, because the catheter is designed for single use only, the circuit board ;preferably contains an EPROM chip that shuts down the circuit board approximately twenty-four hours after the catheter has 'been ' used. 3'his pxevents the catheter, or at least the location sensor, from, being ~rzs~d twice.
25 If desired, two or more pullet wires can be provided to enhance fibs ability to manipulate the intermediate section. In such an embodiment, a second pvller wire and a surrounding second compression coil extend through the catheter body and into an additional off axis lumen in the intermediate section. The first pullet wire is preferably anchored proximal to the anchor location of tt~,e second pullet wire. Suitable des~a.gns of catheters having two or more pullet wires,.
including suitable control handles for such embodiments, are described, for example, in U.S.
Patent Nos. fi,123,699, 6,171,277, 6,183,435, b,183,463, 6,198,9?4, 6,21,4,407, and 6,27,746, the disclosures of which axe incorporated herein by reference.
The preceding description. has been presented with reference to presently preferred e~nbodiznentg of the invention. Workers skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in th,e described structure may be practiced without meaningfully departing from the principal, spirit and scope of this invention.
Accordingly, the Foregoing descriptian should not be reap as pertaining oaly to the precise structures described and illustzated in the accompanying dxawi~s, but rather should ~e read consistent with and as support to the following claims which are to have their fullest and fair scope.
The present invention relates to an improved steerable electrode catheter having au irrigated ablation electrode that is particularly useful for treating atrial ~abrillation.
BACKGROUND OF THE INVENTION
Attial ~brillation is a com~tnon sustained cardiac arrhythmia and a rna,~or cause of stroke. This condition is perpetuated byreentrant wavelets propagating in an abnarmal atrial-1 ~ tissue substrate. Various approaches have been developexl to interrupt wavelets, including surgical or catheter-mediated atriotomy. It is believed that to treat atrial fibrillation by radio-frequency ablation using a catheter, coatinuaus linear lesions must be formed to segment the heart tissue. By seg~n.enting tlac heart tissue, no electrical activity can be transmitted from one segment to another. Preferably, the segments are made trao small to be able to sustain the 1 ~ fibrillatory process. A preferred technique for treating atrial fibrillation by radio-frequency ablation would be a "branding iron" approach, where a relatively iong electrode can be held stationary in good contact with the heart wall while ablation is completed. In this way, a continuous transmural burn may be effected.
U.8. Patent No. 5,80,428 to Nelson et al. discloses a radia frequency ablation ~ catheter system having a flexible, tubular electrode for creating a continuous linear lesion.
The tubular electrode as selectively extendable from the distal end of the catheter. The catheter f~tu~ther comprises axechanistns for remotely manipulating and extending the electrode. However, having an extendable electrode house in the catheter provides less degrees of freedom with respect to the shape, size and leng~ of the tubular electrode.
25 M°~o~, ~e physician has to deal with additional. moving and rnatuipulatable parts, adding complexity to the procedure. Further, a retractable electrode can cause contamination because blood or coagulate on the electrode can he pulled into a~ad entrapped inside the catheter. The entrapped coage~..late can also affect the ability of the electrode to be further extended and retracted. Accordingly, it would be desirable to provide a catheter design having an electrode for creating linear lesions that overcomes these drawbacks.
_I.
SLJwIMARY OF THE INVENTION
1 The invention is directed to an improved catheter for ablating tissue. The catheter comprises an elongated generally-tubular catheter body having proximal and distal ends and at least one lumen extending therethrough. A non-retractable. ablation assembly is attached to the clistal. end of the catheter body. The ablation assembly wmprises proximal and distal non-conductive tubings, each having a lumen extending th~xethrough, and a generally tubular electrode mounted between the proximal and distal z~on ~c~ndtxctive tubings.
The tubular electrode is formed of a material having shape-memory and has at least oxae irrigation port through which .fluid can pass from the inside to the outside of the electrode.
The ablation assembly further comprises a non-conductive protective tubing extending generally parallel to 1~ and along the outside of the tubular electrode that has proxunal and distal ends extending into the proximal and distal non-conductive tubings, respectively. The catheter futxher comprises at least one of an electrode lead wire and a temperature sensor wire, and preferably both, extending through the nort-conductive protective tubing and catheter body. Ths electrode lead wire has a distal end mounted to a ring electrode mounted on thedistal non-conductive tubing. Th~
1$ temperature sensor ~avire has a distal end mounted on or under the distal non-conductive tubing.
The catheter also includes means for introducing fluid into the tubular electrode.
In another embodiment, the invention is directed to a catheter for ablating tissue comprising a catheter body having an outer wall, proximal and distal ends, and at least one lumen extending theretluough. An intermediate section comprising a segment of flexible tubing having ~ proximal and distal ends and at least one lumen therethroulh is fixedly attached at its proximal end to the distal end of the catheter body. A non-retractable ablation assetxtbly as described above is attached to the distal end of the intermediate section, An infusion tube extends through a lumen in the intermediate sactivn and has a distal end in fluid communication with the proximal end of the tubular electrode.
25 ~ ~o'~er embodiment, the invention is directedl to a method for treating atrfal fbrjllatfon. The method comprises inserting the distal end of a catheter as described above into an atria of the heart, and formfag at least one linear lesion fn the atrfal tissue with the tnbnlar electrode.
_2-In yet another embodiment, the invention ~ dimeeted to a method fgr treating atrial fibrillation comprising providing a catheter as described above and a guiding sheath having proximal and distal ends. The guiding sheath is inserted into the body so that the distal end of the grading sheath is in an atria of the heart. The catheter is inserted into the proximal end of the guiding sheath and fed through the guiding sheath so that the distal end of the catheter extends out the distal end of the guiding sheath. The method further comprises formfng at least one Ifnear lesion in the atrial tissue with the tubular electrc'de.
laEgCRInTION' OF 'THE DRF~WI1~TGS
These and other features and advantages of the present invention will be better understood by reference to the following detailed description when ~conszdered in conjunction with the accompanying drawings wherein;:
FIG, 1 is a side cross-sectional view of an embodiment of the catheter of the invention.
FIG. 2 is a side cross~sectiona'lwiew of a catheter body according to the invention, including the junction between the catheter body and interrraediate section.
FICA. 3A is ;~ side cross-sectional ~~iew of the proximal end of a tubular ablation assembly according to the invention.
FIG. 3E is a side cross-sectional vievcr of the distal end of the.tubular ablation assembly of FIG. 3~1"
FIG. 4 is an end cross-sectional view of the tubular ablation assembly of FIG.
3A along line 4-4.
FIGS. 5A and SB axe perspective views of an alternate tubular ablation assembly according to the invention.
FIG. 6 is a side cross-sectional view of the distal end of an alternate tubular ablation assembly according to the invention.
25 FIG. 7 is~ a cross sectional view of a portion of tl~e catheter intezmediate section showing one means for attaching the pulley wire.
FIG. 8 is a top cross sectional views of a preferred prxller wire anchor.
FzG. 9 is a side cross sectional views of the pullet wire anchor of FIG.' 8 0 FIG.10 is a side cross-sectional view of the distal end of tb,e tubular ablation assembly of 30 ~ Steve embodiment including a location sensor.
DETAILED DBSCRIPTION
,3_ 1n a particularly preferred embodiment of the invention there is provided a steerable 1 catheter having an irrigated tubular ablation electrode. As shown in FZG 1, catheter 10 comprises an elongated catheter body 12 having proximal and distal ends, an intermediate section 14 at the distal end of the catheter body, an ablation assembly IS mounted at the distal end of the intermediate section, and a control handle 1, 6 at the proximal end of the catheter body.
With reference to 11'IG. 2, the catheter body 12 comprises an elongated tubular construction having a single, axial or central lumen 18, The catheter body >l2 is flexible, i.e., bendable, but substantially noh.-compressible along its length. The catheter body 12 can be of any suitable construction and made of any suitable material.. A presently preferred construction comprises as outer wall 22 made of polyurethane or PEBAX. 'The outer wall 22 comprises an imbedded braided mesh of stainless steel or the lilts to increase torsional sti#Tness of the catheter body iz so that, when the control handle 16 is rotated, the intermediate section 14 of the catheter 10 will rotate in a corresponding manner.
The outer diameter of the catheter body 12 is not critical, but is preferably no more than about 8 ftench, more preferably 7 french. f,ikewise the thickness of the outer wall 22 is net 1 ~ critical, bt~t is thin ;,rough so :hat the central lumen 1S can accommodate an infusion tube, a puller wire, lead wires, and any other wires, cables or tubes, If desired, the inner surface of the outer wall 22 is lined with a stiffening tube (not shown) to provade improved torsional stability.
A particularly preferred catheter has an outer wall 22 wirb: an outer diameter of from about 0.090 inch to about 0.94 inch and an izaner diameter of from about: 0.061 inch to about 0.065 inch.
Iu the depicted embodiment, the intermediate section 14 comprises a shoat section of tubing 19 having three lumens. The frat lumen 30 electrode carries lead wires S0, the second lumen 32 carries a pulley wire 64, and the third lumen 34 carries an infusion tube 44. The wires and tube are described iri more detail below. 'The tubing 1.9 is made of a suztable non-toxic material that is preferably more i~exible than the catheter body 12. ~, presentlypreferred material for the tubing 19 is braided polyurethane, i.e., polyurethane with an embedded mesh of braided stainless steel or the like, that is more flexible than the catheter body, Tile number atld size of the lumens as not critical and can vary dependinn on the various,w~ires, tubes and other components carried by the catheter, In a preferred embodiment, the intermediate section 14 has an outer diameter ranging from about 5 French {.066 inch) to 8 French {.105 inch), and the first lumen 30 and accord lumen 32 are generally about the same size, each having a diameter of from about 0.020 inch to about 0.024 inch, preferably 0.022 inch, with the third lumen 34 having a slightly larger diameter of from about 0.032 inch to about 0.038 inch, preferably 0.035 inch.
A preferred means for attaching then catheter body 12 to the intermediate section 14 is illustrated in IETG. 2. The proximal end of the intermedla~te section ~,4 comprises an outer circumferential notch Z4 that receives the inner surface of the outex wall 22 of the catheter 1 body 12. The intermediate section 14 and catheter body 12 are attached by glue or the like.
If desired, a spacer (not showtl) cats be located within the catheter body at its distal end, adjacent the proximal end of the zntennediate section. The spacer provides a transition in, flexibility at fhe junction of the catheter body and ixltermediate section, which allows this junction to bend smoothly without folding ox kicking. A catheter having such a spacer is described in U.S. Patent No. 5,964,75, the disclosure of which is incorporated herein.by reference.
At the distal end of the intermediate. section 1 A is a non-retractable ablation assembly 15, as shown in FIGs. l, 3A, 3B and 4. In the depicted embodiment, the ablation assembly 15 has proximal and distal ends and comprises a tubular electrode 38 between a non-conductive distal segment 40 and a non-conductive proximal segment 42, all described further below.
The ablation assembly 15 is shaped so that it is beat relative to the straight tubing 19 of the intermediate section 14.. As used herein, the team "Gent" when used to describe the ablation assembly 15 is intended to mean that the assembly is carved, bent or angled to any extent at any point along its leng~.. With this design, when a physician. deflects the intermediate section 14, the tubular electrode 3H is pressed against the tissue, creatit~,g a "branding imn" effect. In contrast, a physician using a straight catheter having one or more electrodes along the length of its distal end to create a linear lesion wall find it difficult to provide the same amount of pressure on the tissue with the electrode(s). The particular shape of the ablation assembly 15 depends on the desired application, i.e., the precise lacauon in the atrium, or elsewhere at which the catheter is to be used, and for example, can be bent in a single pleas or in multiple planes.
In one embodiment, as shown in FIG. 1, the tubular ablation assembly 15 is generally L-shaped and lies in a single plane. The proximal end of the assembly 1S is generally straight cad collinear with the tubin19 of the intermediate section 14. 2'he assennbly 15 bends at a point along its length. Preferably the straight proximal end of the assembly 15 is sufficiently long to mount one or more mapping rang electrodes, as described in more detail below.
At~er the bend, the distal end of the assembly 15 is generally stxaight. 'The exposed poztion of the tubular electrode 38, i.e., the portion that is not covered by any non~.conductive tubing, is generally L-shaped, but alternatively could be generally straight or one of a variety of other shapes, such as fat described below. T'he non-conductive distal segment 40 is generally collinear with the distal end of the tubular electrode 38, The ablation assembly 15 of this embodiment is preferably shaped so that it forn.~s an .angle a ranging from about 60 degrees to about 140 de;rees. This design is particularly useful for ablation in the open region of the heart.
In ate alternative e~tnbodin~ent, shown in FIGs. 5A and 5B, the ablation assembly 1S is gently lasso-shaped, The proximal end of the assembly 15 is generally collinear with the tubing I9 of the intermediate section I4. The a'ssernbl~ IS cuz~es at its distal end to form a slanted semi-circle, i.e., lying in more than one plane, as best shown in ~'I~. 5B. In this embodiment, the tubular electrode 38 is generally curved. 'This design is particularly useful for ablation in or around a blood vessel, such as the pulmonary vein. As would be recognized by one skilled iti the art, other shapes can be provided for the electrode assembly 15. For example, in the embodiment of FIG. 5B, the tubular electrode 38 forms a full cizcle.
A,s used herein, the term "tubular electrode" refers not only to traditional tubular, i.e., cylindrically-shaped, structures having a hollow interior, but also to any other elongated, generrally-hollow bodies having, for example, au ovular, square, or other geometricaPly shaped cross-sectional. Other shapes will be apparent to those skilled in the art to achieve the purpose described further herein.. Preferably the tubular electrode 38 has an izmer diaxaeter ranging from about 0.018 inch to about 0,024 inch and an outer diameter ranging from about 0.020 inch to about 0.028 inch. 'The length, of the exposed portion of the tubular electrode 38 eau vary depeadiug ca the desired length of the lesion to be created, and preferably ranges from about 8 mm to about 2 cm, more preferably from about 1.2 cna to about I.~ em, to create arelatively long 1 S lesion.
The tubular electrode 38. is made of a material ha ing shape-memory, i.e., that can be straightened or beat ant of its original shape upon exertion of a force and is capable of substantiallyreturning to its original shape upon removal ofthe force.
,kparticularPypreferred material for the tubular electrode is a nickeUtitanium alloy. Such aPloys typically comprise about 55% nickel and 45% titanium, but xriay comprise frown about 54% to about S7%
nickel with the balance being tita~c~ium. A~preferred nickelltitariium alloy is nitinol, which has excellent shape memory, together with ductility, strength, corrosion resistance, electrical resistivity and temperatcue stability. A particularly preferred material is nitiztol fogm from 50.8 atomic% nickel, with the balance titanium:, having an austenite fish and a transition temperature from about 2S +5°C to about -25°C, which is coxrmiercially available from I~itinol Device Corp. (Fremont,, California).
T"he tubular electrode 3~ contains a series of irrigation ports 39 through which fluid can pass during an ablation procedure. Preferably the irrigation ports 39 axe located only an the side of the tubular electrode 38 that is to be in contact with the tissue to be ablated. The irrigation ~0. ports 39 caw be any suitable shape, such as rectangular or ovular slots or round holes. 1'n~ the embodiment shown in FIGs. l, 3 atRd 4, the tubular electrode 38 has six irrigation ports 39, each forming a slot or ellipse with a length preferably ranging from about 0.018 inch to about 0.020 inch. Preferably the irrigation p~rts 3~ are spaced apart from each ofher a distance o~about 0.125 ixxch. Having a limited number of irrigation ports 39 on the side of the tubular electrode 38 35 m ~nt~t with the tissue to be ablated allows for mare even fluid flow out of the electrode. As would be recognized by one s~lled in the art, the precise nau~nber, size, shape said arrang~ent of 1 irrigation poxts 39 can, vary as desired.
An electrode lead wire 50 is attached to the tubular ~;,lectrode 38 for electrical connection to a suitable corurtectar (not shown), which is attached to a source of energy (not shown). In the depicted ernbodimertt, the electrode lead wire 50 is wrapped around the proximal end of the tubular electrode 3~ and soldered, welded or othe~ise attt~ched to the electrode. 'The electrode lead wire SO for the tubular electrode 38 extends through t~~e fret lumen 30 of the intermediate section 14, through the central lumen 18 of the cathete}r body 3.2, and through the eon~°ol handle 16, and are connected tai a suitable source of ablation energy (not shown) by means of an appropriate connector as is generally k~xown in the art.
10' The distal and proximal non-conductive segtnenfis 4~and 42 of the ablation assenxbly 15 comprise distal and proximal non-conductive cov gs 41 and 43, respectively, which ~
preferably made of polyimide or other biocoxpapatible plastic. The distal non-conductive covering 41 extends over the distal end of the tubular ellectrode 38, and the proximal non-conductive covering 43 extends over the proximal end of the tubular electrode.
15 ~ the depi;,i~:d cmmbodiment, two distal rinn electrodes 47 are mounted on the distal non-conductive covering 41, and tvvo proximal rind electrodes 4~8 axe tmounted on the proximal non-conductive covering 43. The ring electrodes 47 and 48 can be made ofany suitable material, and are preferably made of platinum or platinum and iridiuan. Each z~,g electrode cast be mounted by any suitable technique, and is preferably mounted by first fbrming a hole ixx the non-conductive ~ covering. An electrode lead wire 50 is fed through the hole, and the ring electrode is welded ~
place over the lead wire and non-conductive covering. The presence and number of ring electrodes can vary as desired.
Additionally, one or more temperature sensing cleans are pxovided for the tubular electrode 38. Any conventional temperature sensing mean,., e.g., a thermocouple or thermistor, 25 may be used. In the depicted embodiment, two thermocouples az°e provided, each of which is formed by a wire pair. ~ne wire of the wire paax is a copper wire, e.g., a number 38 copper wire, and the other wire of the wire pair is a congtantat~ vviz°e, which gives support and strength to the wire pan. Specifically, a distal thermocouple 45 is pro~rided for measurement distal to the exposed portion of the tubular electrode 38, and a proximal thermocouple 46 is provided for 30 measurement proximal to the exposed portion of the tubuhur electrode. Each thermocouple 4S
and 46 is preferably mounted to a corresponding ring electrode 47 and 48, as shown in FIC'as. 3A
and 3B, by weld, solder or other suitable method. The placement of the thermocouples in the depicted embodiment is particularly desirable because they are located out of the irrigation zone, i.e., the region in which the irrigation fluid primarily flows firom the tubular elects ode 38 through 35 the inigation ports 39. The presence of the fluid can reduce the accuracy of the tissue _7_ temperature measurements by the thermocouples. Accordingly, it is desirable to place the 1 thermocouples or other temperature sensing means as close as possible to the tubular electrode 38 while outside the irrigation zone.
In the depicted embodiment, a non-conductive protective sheath. 52 is provided along the outside of the tubular electrode 38 for carrying the distal thermocouple wires 45 and electrode lead wires 50 connected to the distal ring electrodes 47, The protective sheath 5z extends generally parallel to the tubular electrode 38 and is preferably attached tQ
the tubular electrode along the entire exposed portion of the tubular electrode. '1~he protective sheath 52 is preferably made of polyurethane or polyimide or other suitable bi,ocompatible plastic. rn a preferred embodiment, the protective sheath 52 is glued to the tubular electrode 3S with an adhesive such ~ y CTluse~ and tied in plane using a monoftlament or the like. The tubular electrode 3S and protective sh~ath 52 are then covered with a polyurethane glue or the like, with care beitag taken not to cover the irrigation ports 38, and the monofilament is removed after the polyurethane glue cures. The proximal and distal ends of the protective sheath, 52 extend into the proximal and distal non-conductive coverings 43 and 41. Alternatively, the distal electrode lead wires 50 and ~s~ ~~ocouple was 45 care extend through the tubular electrode 38, although such wires can adversely affect the flow of irrigation fluid through the tubular electrode.
All of the electrode lead wires 50 and therrnoeouple wires 45 and 46 extend through the first lumen 30 in the intermediate seotiox~ 14. Within the catheter body 12, the wires 45, 46 and 50 extend through a protective tubix~n 36 to keep the wires from contacting ~ther components Mending through the central lumen 18. The protective tubing 36 is preferably anchored at its distal end to the proximal end of the intermediate section 14 by gluing it in the dust lumen 30 with polyurethane glue or the like. The electrode lead wires 5C~ them extend out through the control handle 16 an"d to a suitable monitoring device or source of ablation energy (not shown), as appropriate, via a suitable connector (z~ow shown), as is generally known in the an. The ~~°couple wires 45 and 46 similarly extend out through the control handle 16 and to a connector (not shown) connectable to a temperature monitor (not shown).
The distal end of the ablati~n assembly 15 is preferably provided with an atraumatic construction to prevent the distal end of the tubular electrode 38 from penetrating tissue. In the depicted embodiment, the atraumatie construction comprises a tightly wound coil spring 56 m~e~ for example, of stainless steel, such as the mini guidewire commercially available from Cordis corporation (Nl~ami, Florida). The coil sprig 56 is'. mounted within the dzstal arid of the distal non-conductive covering 41 and held in place at its prr~ximal and distal ends with polyurethane glue 6d or the like. in the depicted embodiment, the coil spring 56 has a length of about 0.50 inch, hut can be any desired length for example, ranging from about 0.25 inch to bout 1.0 inch, The coil spring 56 is preferably sufficiently long to serve as an anchor for _g_ introducing the catheter into a buidinc sheath, particularly when the tubular electrode is curved 1 and must be straightened upon introduction into the sheath. 'W'ithout having the coil spring 56 as an anchor, the tubular electrode 38 has a tendency to pull out of the guiding sheath upon its introduction into the guiding sheath. Additionally, if desired, the coil spring 56 can be formed, at least in part, of a radiopaque material to aid in the positioning of the tubular electrode 38 under fluoroscopy.
The coil spring 56 is preferably secured to the distal end of the catheter with a safety wire 54. The distal end of the safety wire S4 is hooked around the coil spring 56 and glued in place, The safety wire 54 extends through the tubular electrode 38 and its proximal end is wrapped around the proximal end of. the tubular electrode and optionally soldered, glued or °~~'ise attached in place. The proximal end of the safety wire 54 can be secured to the catheter in any other suitable manner. For example, i~n an alternative embodiment, (not shown the safety wire can extend through the protective sheath 42 and through the catheter body I2 and be anchored within the control handle 16.
Tile distal non-conductive segment 40 can have any other suitable atraumatic construction fat pt'°tects the tubular electrode 38 from puncturing tl~e heart tissue. An example of an alternative atraumatic construction, as shown ire FIG, 6, is i:c the form ofa ball. To form the ball, the distal end of the distal non-conductive covering 41 is covered with a shoat length of thick non-conductive tubing 58, made of polyimide, polyur~rthane. ox the, like.
Polyurethane adhesive 60 or the like is applied into and around the edges of the non-conductive tubing 58 to round off the. edges of the distal end of the distal non-conductive segment 40.
A pulle2~ wire 64 is provided for deflection of the interm~iate section 14:
The pullet wire 64 extends through the catheter body 12, is anchored at its proximal end to the control handle 16, and is anchored at its distal ennd to the intermediate section 14.
The pullet wire 64 is made of at~y suitable metal, such as stainless steel or Nitinol, aad is preferably coated with Teflon~ or the like. The coating .imparts lubricity to the pullet wire 64. The pullet wire 64 preferably has a diameter ranging from about 0.006 to about 0.010 inch.
A compression coil 66 is situated within the catheter.body 12 in surrounding relation tv the pullet wire 64. The compression coil 66 extends from tho proximal end of the catheter body 12 to the proximal end ofthe intermediate section 14. The compression coil 66 is made of ~y ~~ble metal, preferably stainless steel. The compression coil 66 is tightly wound on itself to provide flexibility, i.e., bending, but to resist eompr~essaou, The inner diameter of the compression coil 66 is preferably slightly larger than the diameter of the pullet ~wire 64. The Teflon~ coating on the pullet wire 64 allo~srs it to slide freely within the compression coil 6G. If desired, particularly if the lead wires 50 are not enclosed 'by a protective tubing 36, the outer s~~e of the compression coil 66 is covered by a flexibl~, non-oox~ductive sheath 68, e.g., made of polyimide tubing, to prevent contact between the compression coil and any other wires within the catheter body 12.
The compression coil 66 is anchored at its proxitxtal end to the outer wail 22 of the catlzetex body 12 by proximal glue joint 70 and at its distal'. end to the intermediate section 14 by distal glue joint 72. Both glue joints 7~ and 72 preferably comprise polyurethane glue or the like.
The glue may be applied by means of a syringe or the like through a hole made between the outer surface of the catheter body 12 arid the central lumen 18. such a hole may be formed, for example, by a needle or the like that punctures the outer wall 22 of the catheter body 12 which is heated sufficiently to form a permanent hole. The glue is then ~t~°oduced through the hole to the outer surface of the compression coil 66 and wicks around the outer circumference to form a glue 1 ~ ,point about the entire circumference of the compression coil 66.
The pulley wire 64 extends into the second lumen 32 of the intermediate section 14.
preferably the pulley ware 64 is anchored at its distal extd to the side of the inteFmediate section 14, as shown in FTGs. 7 to 9. T-shaped anchor 78 is formed which comprises a short piece of tubular stainless steel 80, e.g., ~hypodern~i.c stock,. which is fitted over the distal end of 15 ~e paler v~''~ ~ aid cnmped to ~~xedly secure it to the pulley wire. The distal end of the tubular stainless steel SO is fixedly attached, e.g., by welding, to a stainless steel cross-piece 82 such as stainless steel ribbon or the like. The cross-piece 82 sits in a notch 84 in a wall of the flexible tubing 19 that extends into the second Lumen 32 of the intermediate section 14. The stainless steel cross-piece S2 is larger than the opening and, therefore, cannot be pulled through the opening. The portion ofthe notch 84 not filled bythe cross-piece S2 is filled with ,glue S6 or the like, preferably a polyurethane glue, which is harder than. the material of the flexible tubing i9. Rough edges, if any, of the crass-piece 82 are polished to provide a smooth, continuous surface with the outer surface ofthe.flexible tul9ing 19. Within the second lumen 32 of the intermediate section 14, the pulley wire 64 extends through a plastic, preferably Teflon, 25 pulley wire sheath 74, which prevents the pulley wire 64 from. cutting' into the wall of the intermediate section 14 when the intermediate section is deflected. Any other suitable technique for anchoring the pulley wire 64 in the intermediate section 14 can also be used.
Longitudinal movement of the pullet wire 42 relative to the catheter body I2, which results in deflection of the intermediate section 14, is accomplished by suitable maxtipulation of the control handle 16. Examples of suitable control handles for use in the present invention are disclosed, for example, in U.S. latent I~~s. Re 34,502 anti S,S97,5Z9, the entire disclosures of which are incorporated herein by~ reference.
Within the third lumen 34 of tho intermediate section 14 is provided an infusion tube 44 for infusing fluids, e.g., saline, to cool the tubular electrode 3g ~.d surrounding tissue during ablation. The infusion tube 44 extends through the third lumen 34 of the intermediate section 14, _1~_ through the catheter body 12, out the proximal end of the control handle 16, and ternninates in a 1 luer hub 7d or the like at a location proximal to the control handle. In an alternative azrangement, a single lumen side arm (not shown) is fluidly connected to the central Imnen 18 near the proximal end of the catheter body 1Z, as described in more; detail in LT.S.
Patent No. 6,120,476, the entire disclosure of which is incorporated herein by reference.
Alternatively, the infusion tube 44 can terminate within the distal end of tho third lumien 34 of the intermediate section 14, with a second infusion tube provided that extends from the proximal end of the third lumen, through the catheter body 12 and out through the contrcel handle 16. Such a design is also described in more detail in LT.S. Patent No. 6,120,476. As shown In FIG. 3, the distal end of the you tube 44 extends over the proximal end of the tubular electrode 38, including the Iead ~e 50 and safety wire 54 wrapped around the tubular electrode. '1"he iatfusion tube 44 is attached to the tubular electrode 38 with polyurethane glue or the like, which also acts to seal. the third lumen 34 so that ffuid$ cannot pass into or out of the third lumen other than through the infusion tube and tubular electrode.
In use, a suitable guiding sheath is inserted into the patient. An example of a suitable guiding sheath for use in connection with the present invention is the Preface's Braiding Guiding Sheath, commercially available from C:ordis Webster (Diatxwnd Bar, California). The distal end of the sheath is guided into one of the atria. A catheter in accordance vcrtith the present invention is fed through the guiding sheath until its distal end extends out of the distal etad ofthe guiding sheath.. As the catheter is fEd through the guiding sheath, the tubular electrode 38 can be 0 ~ straightened to fit through tJ~e sheath, and it will return to its original chap a upon removal of fibs sheath.
The tubular electrode 38 is then used to form continuous linear lesions by ablation. .t~s 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 ~e wavelet. Anatomical structures, referred to as "atrial trigger spots", are those regions in the heart having limited or no electrical conductivity and are described ~
Haassaguerre et al., "Spontaneous Initiation 'of Atrial Fibrillation by Ectopic a3eats C3riginating in the Pulmonary veins", New Eland Journal of Medicine, 339:659-666 (Sept. 3,1998), the disclosure ofwhich is incorporated herein by reference. The linear lesions typically have a length of from about 1 ~ to about 4 cm, but can b~ longer or shorter as necessary for a particular procedure, The thermocouples or other temperature sensing means can be used to rttonitor the temperature of the tissue during ablation.
Iu an alternative embodiment, as shown m FIG. 1 i3, the ablation assembly 15 further includes a location sensor 61 for providing IaGation infornr~ation about the ablation assembly.
fly ~e~location sensor 61 comprises a magnetic-field responsive coil, as described in U.S.
-11~
Fatent No. 5,391,199, or a plurality of such coils, as described in International Publication 1 WO 9f!~5758, The plurality of coils enables six-dnmensional position and orientation coordinates to be deter~ned. Alternatively, any sultable position Sensor kctowmn the art may be used, such as electrical, magnetic or acoustic sensors. Suitable location sensors for use with the present invention are also described, for example, in U.S. Patent Nos.
5,558,091, 5,443,489, 5,480,422, 5,546,951, ~ and 5,548,809, and International Publication Nos. WO
95!02995, WO 97/24983, and WO 98/29033, the disclosures ofwhich are incozporatedhereinbyreference.
In the depicted embodiment, the location sensor Gl. is ncaounted in the non-conductive distal segment 40 within the distal .non-conductive covering 41, distal. to the distal end of the tubular electrode 38 and proximal to the proximal end of the coil spring ~6. ~
accordance with 10. the invexttion, the location sensor 61 could be mounted at other positions within the ablation assembly 13 depending on the precise position on the assembly to be located duxing a procedure.
The location sensor 56 is connected to a sensor cable 62 that extends through the protective sheath 52, the catheter body 12 and control handle 16 and ot~t the proximal end of the control handle within an umbilical cord (not shown) to a sensor control module (not shown) that houses a .
15 circuit board (not shown). Alternatively, the circuit board can be housed within the control handle x6, for example, as described in U.S. Patent No. &,Q24,?39, the disclosure of which is incorporated. herein by reference. The sensor cable 62 comprises multiple wires encased within a plastic covexed sheath. 1n the sensor control xriodule, the wires of the sensor cable are connected to the circuit boaxd. The eirca~it board amplifies the signal received from the corresponding 20 location sensor and transmits it to a computer in a form understandable by the computer by means of the sensor connector at the proximal end of the sensor control module. Also, because the catheter is designed for single use only, the circuit board ;preferably contains an EPROM chip that shuts down the circuit board approximately twenty-four hours after the catheter has 'been ' used. 3'his pxevents the catheter, or at least the location sensor, from, being ~rzs~d twice.
25 If desired, two or more pullet wires can be provided to enhance fibs ability to manipulate the intermediate section. In such an embodiment, a second pvller wire and a surrounding second compression coil extend through the catheter body and into an additional off axis lumen in the intermediate section. The first pullet wire is preferably anchored proximal to the anchor location of tt~,e second pullet wire. Suitable des~a.gns of catheters having two or more pullet wires,.
including suitable control handles for such embodiments, are described, for example, in U.S.
Patent Nos. fi,123,699, 6,171,277, 6,183,435, b,183,463, 6,198,9?4, 6,21,4,407, and 6,27,746, the disclosures of which axe incorporated herein by reference.
The preceding description. has been presented with reference to presently preferred e~nbodiznentg of the invention. Workers skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in th,e described structure may be practiced without meaningfully departing from the principal, spirit and scope of this invention.
Accordingly, the Foregoing descriptian should not be reap as pertaining oaly to the precise structures described and illustzated in the accompanying dxawi~s, but rather should ~e read consistent with and as support to the following claims which are to have their fullest and fair scope.
Claims (15)
1. A catheter for ablating tissue, the catheter comprising:
an elongated generally-tubular catheter body having proximal and distal ends and at least one lumen extending therethrough;
a non-retractable ablation assembly attached to the distal end of the catheter body, the ablation assembly comprising:
proximal and distal non-conductive tubings, each having a lumen extending therethrough, a generally tubular electrode mounted between the proximal and distal non-conductive tubings, the tubular electrode being formed of a material having shape-memory having at least one irrigation port through which fluid can pass from the inside to the outside of the electrode, and a non-conductive protective tubing extending generally parallel to and along the outside of the tubular electrode and having proximal and distal ends extending into the proximal and distal non-conductive tubings, respectively;
at least one of an electrode lead wire and a temperature sensor wire extending through the non-conductive protective tubing and catheter body, the electrode lead wire having a distal end mounted to a ring electrode mounted on the distal non-conductive tubing, and the temperature sensor wire having a distal end mounted on or under the distal non-conductive tubing; and means for introducing fluid into the tubular electrode.
an elongated generally-tubular catheter body having proximal and distal ends and at least one lumen extending therethrough;
a non-retractable ablation assembly attached to the distal end of the catheter body, the ablation assembly comprising:
proximal and distal non-conductive tubings, each having a lumen extending therethrough, a generally tubular electrode mounted between the proximal and distal non-conductive tubings, the tubular electrode being formed of a material having shape-memory having at least one irrigation port through which fluid can pass from the inside to the outside of the electrode, and a non-conductive protective tubing extending generally parallel to and along the outside of the tubular electrode and having proximal and distal ends extending into the proximal and distal non-conductive tubings, respectively;
at least one of an electrode lead wire and a temperature sensor wire extending through the non-conductive protective tubing and catheter body, the electrode lead wire having a distal end mounted to a ring electrode mounted on the distal non-conductive tubing, and the temperature sensor wire having a distal end mounted on or under the distal non-conductive tubing; and means for introducing fluid into the tubular electrode.
2. The catheter according to claim 1, wherein the ablation assembly is bent relative to the tubing.
3. The catheter according to claim 1, further comprising an intermediate section comprising a segment of flexible tubing having proximal and distal ends and at least one lumen therethrough, wherein the proximal end of the intermediate section is fixedly attached to the distal end of the catheter body and the proximal end of the ablation assembly is fixedly attached to the distal end of the intermediate section,
4. The catheter of claim 3, wherein the segment of flexible tubing of the intermediate section is more flexible than the catheter body.
5. A catheter according to claim 1, wherein the introducing means comprising an infusion tube extending through the catheter body and having proximal and distal ends, wherein the distal end of the infusion tube is in fluid communication with the proximal end of the tubular electrode,
6. A catheter for ablating tissue, the catheter comprising:
a catheter body having as outer wall, proximal and distal ends, and at least one lumen extending therethrough;
an intermediate section comprising a segment of flexible tubing having proximal and distal ends and at least one, lumen therethrough, the proximal end of the intermediate section being fixedly attached to the distal end of the catheter body;
a non-retractable ablation assembly attached to the distal end of the intermediate section, the ablating assembly comprising:
proximal and distal non-conductive tubings, each having a lumen extending therethrough, a generally tubular electrode mounted between, the proximal and distal non-conductive tubings, the tubular electrode being formed of a material having shape-memory having at least one irrigation port through which fluid can pass from the inside to the outside of the electrode, and a non-conductive protective tubing extending generally parallel to and along the outside of the tubular electrode and having proximal and distal ends extending into the proximal and distal non-conductive tubings, respectively, at least one of an electrode lead wire and a temperature sensor wire extending through the non-conductive protective tubing and catheter body, the electrode lead wire having a distal end mounted to a ring electrode mounted on the distal non-conductive tubing, and the temperature .
sensor wire having a distal end mounted on or under the distal non-conductive tubing; and an infusion tube extending through a lumen in the intermediate section and having proximal and distal ends, wherein the distal end of the infusion tube is in fluid communication with the proximal end of the tubular electrode,
a catheter body having as outer wall, proximal and distal ends, and at least one lumen extending therethrough;
an intermediate section comprising a segment of flexible tubing having proximal and distal ends and at least one, lumen therethrough, the proximal end of the intermediate section being fixedly attached to the distal end of the catheter body;
a non-retractable ablation assembly attached to the distal end of the intermediate section, the ablating assembly comprising:
proximal and distal non-conductive tubings, each having a lumen extending therethrough, a generally tubular electrode mounted between, the proximal and distal non-conductive tubings, the tubular electrode being formed of a material having shape-memory having at least one irrigation port through which fluid can pass from the inside to the outside of the electrode, and a non-conductive protective tubing extending generally parallel to and along the outside of the tubular electrode and having proximal and distal ends extending into the proximal and distal non-conductive tubings, respectively, at least one of an electrode lead wire and a temperature sensor wire extending through the non-conductive protective tubing and catheter body, the electrode lead wire having a distal end mounted to a ring electrode mounted on the distal non-conductive tubing, and the temperature .
sensor wire having a distal end mounted on or under the distal non-conductive tubing; and an infusion tube extending through a lumen in the intermediate section and having proximal and distal ends, wherein the distal end of the infusion tube is in fluid communication with the proximal end of the tubular electrode,
7. A catheter according to claim 6, wherein the ablation assembly is generally L-shaped.
8. A. catheter according to claim 6, wherein the ablation assembly is generally lasso-shaped.
9. A catheter according to claim 6, wherein the tubular electrode is made of a nickel/titanium alloy,
10. A catheter according to claim 6, wherein the tubular electrode is made of nitinol.
11. A catheter according to claim 6, wherein the tubular electrode has an exposed portion having a length ranging from about 8 mm to about 2 cm.
12. A catheter according to claim 6, wherein the ablation assembly comprises at least one electrode mounted on the distal non-conductive tubing.
13. A catheter according to claim 6, wherein the ablation assembly comprises at least one electrode mounted on the proximal non-conductive tubing.
14. A catheter according to claim 6, wherein the ablation assembly comprises at least one electrode mounted on the distal non-conductive tubing and at least one electrode mounted on the proximal non-conductive tubing.
15. A catheter according to claim 14, wherein the ablation assembly comprises at least one temperature sensor mounted proximal to the exposed portion of the tubular electrode and at least one temperature sensor mounted distal to the exposed portion of the tubular electrode.
15. A catheter according to claim 6, wherein the ablation assembly comprises at least one temperature sensor mounted proximal or distal to the exposed portion of the tubular electrode.
17. A catheter according to claim 6, wherein the ablation assembly comprises at least one temperature sensor mounted proximal to the exposed portion of the tubular electrode and at least one temperature sensor mounted distal to the exposed portion of the tubular electrode.
18. A catheter according to claim 6, wherein the at least one irrigation port is located only on the side of the tubular electrode that is to be in contact with the tissue to be ablated.
19. A catheter according to claim 6, wherein the ablation assembly further comprises an atraumatic design at its distal end, 20. A catheter according to claim 19, wherein the atraumatic design comprises a coil spring mounted within the distal non-conductive covering.
21. A catheter according to claim 6, further comprising a control handle mounted at the proximal end of the catheter body and means for deflecting the intermediate section by manipulation of the control handle.
22. A catheter according to claim 21, wherein the control handle comprises a first member fixedly attached to the proximal end of the catheter body and a second member that is movable relative to the first member.
23. A catheter according to claim 22, wherein the deflecting means comprises a puller wire having a proximal end and a distal end, the puller wire extending from the control handle, through the catheter body and into the a lumen in the intermediate section, wherein the distal end of the puller wire is fixedly secured within the intermediate section and the proximal end of the puller wire is fixedly secured to the second member of the control handle, whereby manipulation of the first member of the control handle relative to the second member of the control handle moves the puller wire relative to the catheter body, resulting in deflection of the intermediate section.
24. A catheter according to claim 6, further comprising a location sensor mounted within the ablation assembly.
25. A catheter according to claim 24, wherein the location sensor is an electromagnetic location sensor.
26. A catheter according to claim 24, wherein the location sensor is mounted within the distal non-conductive covering.
27. A catheter according to claim 24, further comprising s sensor cable having a distal end fixed attached to the location sensor the sensor cable extending through the non-conductive protective tubing, through a lumen in the intermediate section and through the catheter body.
28. A method for treating atrial fibrillation comprising:
inserting the distal end of a catheter according to claim 1 into an atria of the heart;
and forming at least one linear lesion in the atrial tissue with the tubular electrode.
29. A method for treating atrial fibrillation comprising:
inserting the distal end of a catheter according to claim 6 into an atria of the heart;
and forming at least one linear lesion in the atrial tissue with the tubular electrode.
30. A method for treating atrial fibrillation comprising:
providing a catheter as recited in claim 1 and a guiding sheath having proximal and distal ends;
inserting the guiding sheath into the body so that the distal end of the guiding sheath is in ate atria of the heart;
inserting the catheter into the proximal end of the guiding sheath and feeding the catheter through the guiding sheath so that the distal end of the catheter extends out the distal end of the guiding sheath; and forming at least one linear lesion in the atrial tissue with the tubular electrode.
31. A method for treating atrial fibrillation comprising:
providing a catheter as recited in claim 6 and a guiding sheath having proximal and distal ends;
inserting the guiding sheath into the body so that the distal end of the guiding sheath is in an atria of the heart;
inserting the catheter into the proximal end of the guiding sheath and feeding the catheter through the guiding sheath so that the distal and of the caster extends out the distal end of the guiding sheath; and forming at least one linear lesion in the atrial tissue with the tubular electrode.
32. A method according to claim 31, wherein the at least one linear lesion has a length ranging from about 1 cm to about 4 cm.
33. A method for treating atrial fibrillation comprising:
providing a catheter as recited in claim 21 and a guiding sheath having proximal and distal ends;
inserting the guiding sheath into the body so that the distal end of the guiding sheath is in an atria of the heart;
inserting the catheter into the proximal end of the guiding sheath and feeding the catheter through the guiding sheath so that the distal end of the catheter extends out the distal end of the guiding sheath;
deflecting the intermediate section of the catheter so that the tubular electrode is pressed against atrial tissue; and forming at least one linear lesion in the atrial tissue with the tubular electrode.
15. A catheter according to claim 6, wherein the ablation assembly comprises at least one temperature sensor mounted proximal or distal to the exposed portion of the tubular electrode.
17. A catheter according to claim 6, wherein the ablation assembly comprises at least one temperature sensor mounted proximal to the exposed portion of the tubular electrode and at least one temperature sensor mounted distal to the exposed portion of the tubular electrode.
18. A catheter according to claim 6, wherein the at least one irrigation port is located only on the side of the tubular electrode that is to be in contact with the tissue to be ablated.
19. A catheter according to claim 6, wherein the ablation assembly further comprises an atraumatic design at its distal end, 20. A catheter according to claim 19, wherein the atraumatic design comprises a coil spring mounted within the distal non-conductive covering.
21. A catheter according to claim 6, further comprising a control handle mounted at the proximal end of the catheter body and means for deflecting the intermediate section by manipulation of the control handle.
22. A catheter according to claim 21, wherein the control handle comprises a first member fixedly attached to the proximal end of the catheter body and a second member that is movable relative to the first member.
23. A catheter according to claim 22, wherein the deflecting means comprises a puller wire having a proximal end and a distal end, the puller wire extending from the control handle, through the catheter body and into the a lumen in the intermediate section, wherein the distal end of the puller wire is fixedly secured within the intermediate section and the proximal end of the puller wire is fixedly secured to the second member of the control handle, whereby manipulation of the first member of the control handle relative to the second member of the control handle moves the puller wire relative to the catheter body, resulting in deflection of the intermediate section.
24. A catheter according to claim 6, further comprising a location sensor mounted within the ablation assembly.
25. A catheter according to claim 24, wherein the location sensor is an electromagnetic location sensor.
26. A catheter according to claim 24, wherein the location sensor is mounted within the distal non-conductive covering.
27. A catheter according to claim 24, further comprising s sensor cable having a distal end fixed attached to the location sensor the sensor cable extending through the non-conductive protective tubing, through a lumen in the intermediate section and through the catheter body.
28. A method for treating atrial fibrillation comprising:
inserting the distal end of a catheter according to claim 1 into an atria of the heart;
and forming at least one linear lesion in the atrial tissue with the tubular electrode.
29. A method for treating atrial fibrillation comprising:
inserting the distal end of a catheter according to claim 6 into an atria of the heart;
and forming at least one linear lesion in the atrial tissue with the tubular electrode.
30. A method for treating atrial fibrillation comprising:
providing a catheter as recited in claim 1 and a guiding sheath having proximal and distal ends;
inserting the guiding sheath into the body so that the distal end of the guiding sheath is in ate atria of the heart;
inserting the catheter into the proximal end of the guiding sheath and feeding the catheter through the guiding sheath so that the distal end of the catheter extends out the distal end of the guiding sheath; and forming at least one linear lesion in the atrial tissue with the tubular electrode.
31. A method for treating atrial fibrillation comprising:
providing a catheter as recited in claim 6 and a guiding sheath having proximal and distal ends;
inserting the guiding sheath into the body so that the distal end of the guiding sheath is in an atria of the heart;
inserting the catheter into the proximal end of the guiding sheath and feeding the catheter through the guiding sheath so that the distal and of the caster extends out the distal end of the guiding sheath; and forming at least one linear lesion in the atrial tissue with the tubular electrode.
32. A method according to claim 31, wherein the at least one linear lesion has a length ranging from about 1 cm to about 4 cm.
33. A method for treating atrial fibrillation comprising:
providing a catheter as recited in claim 21 and a guiding sheath having proximal and distal ends;
inserting the guiding sheath into the body so that the distal end of the guiding sheath is in an atria of the heart;
inserting the catheter into the proximal end of the guiding sheath and feeding the catheter through the guiding sheath so that the distal end of the catheter extends out the distal end of the guiding sheath;
deflecting the intermediate section of the catheter so that the tubular electrode is pressed against atrial tissue; and forming at least one linear lesion in the atrial tissue with the tubular electrode.
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US10/199,525 US7588568B2 (en) | 2002-07-19 | 2002-07-19 | Atrial ablation catheter and method for treating atrial fibrillation |
US10/199,525 | 2002-07-19 |
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- 2003-07-18 EP EP03254516A patent/EP1382310B1/en not_active Expired - Lifetime
- 2003-07-18 CA CA2435477A patent/CA2435477C/en not_active Expired - Fee Related
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EP1382310A3 (en) | 2004-05-19 |
JP4417050B2 (en) | 2010-02-17 |
US7727230B2 (en) | 2010-06-01 |
CA2435477C (en) | 2013-10-22 |
IL157016A0 (en) | 2004-02-08 |
EP1382310A2 (en) | 2004-01-21 |
US20040015164A1 (en) | 2004-01-22 |
US7588568B2 (en) | 2009-09-15 |
IL157016A (en) | 2011-11-30 |
US20050119651A1 (en) | 2005-06-02 |
EP1382310B1 (en) | 2010-03-03 |
DE60331504D1 (en) | 2010-04-15 |
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