Source: http://www.google.com/patents/US20050070887?ie=ISO-8859-1
Timestamp: 2014-08-22 04:53:47
Document Index: 185650014

Matched Legal Cases: ['art 200', 'art 200', 'art 200', 'art 200', 'art 200', 'art 200', 'art 200', 'art 200', 'art 200', 'art 200']

Patent US20050070887 - Medical probes for creating and diagnosing circumferential lesions within or ... - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsThe present inventions provide assemblies, probes, and methods for creating circumferential lesions in tissue, e.g., the tissue within or around the ostium of a vessel. An ablation probe with an ablative structure can be placed in contact within or around the ostium of the vessel. A diagnostic probe...http://www.google.com/patents/US20050070887?utm_source=gb-gplus-sharePatent US20050070887 - Medical probes for creating and diagnosing circumferential lesions within or around the ostium of a vesselAdvanced Patent SearchPublication numberUS20050070887 A1Publication typeApplicationApplication numberUS 10/672,457Publication dateMar 31, 2005Filing dateSep 26, 2003Priority dateSep 26, 2003Also published asCA2539950A1, EP1663044A1, US7435248, US7959630, US20090018534, WO2005030072A1Publication number10672457, 672457, US 2005/0070887 A1, US 2005/070887 A1, US 20050070887 A1, US 20050070887A1, US 2005070887 A1, US 2005070887A1, US-A1-20050070887, US-A1-2005070887, US2005/0070887A1, US2005/070887A1, US20050070887 A1, US20050070887A1, US2005070887 A1, US2005070887A1InventorsMiriam Taimisto, Josef KoblishOriginal AssigneeScimed Life Systems, Inc.Export CitationBiBTeX, EndNote, RefManReferenced by (17), Classifications (14), Legal Events (3) External Links: USPTO, USPTO Assignment, EspacenetMedical probes for creating and diagnosing circumferential lesions within or around the ostium of a vesselUS 20050070887 A1Abstract The present inventions provide assemblies, probes, and methods for creating circumferential lesions in tissue, e.g., the tissue within or around the ostium of a vessel. An ablation probe with an ablative structure can be placed in contact within or around the ostium of the vessel. A diagnostic probe can be introduced through a lumen within the ablation probe and inserted into the vessel. The energy can be provided to the ablative structure to create a circumferential lesion within or around the ostium of the vessel, and the diagnostic structure can be used to diagnose the tissue to determine whether the circumferential lesion can be properly created. Images(9) Claims(46)
The distal member 26 of the ablation catheter body 24 forms an unconstrained open helically-shaped ablative structure 32 on which ablation electrodes 34 are mounted. The ablative structure 32 defines a longitudinal axis coincident with the longitudinal axis of the remainder of the catheter body 24. The number of revolutions (or �coils�), length, diameter, orientation and shape of the helical structure will vary from application to application. In the illustrated embodiment, the ablative structure 32 revolves around the longitudinal axis of the catheter body 24 two and one-half times in its relaxed state, and can be defined with a proximal coil 36, medial coil 38, and distal coil 40. Although the diameter of the ablative structure 32 can alternatively be substantially constant over its length, as illustrated in FIG. 2, the ablative structure 32 preferably has a generally frusto-conical shape, where the diameter decreases in the distal direction. Specifically, when used in pulmonary veins, the proximal coil 36 of the ablative structure 32 preferably has an outer diameter that will cause it abut the pulmonary vein ostium (e.g., between about 15 mm and about 35 mm), and the distal coil 40 of the ablative structure 32 preferably has an outer diameter suitable for placement within the pulmonary vein (e.g., between about 5 mm and about 10 mm). The ablative structure 32 will, therefore, be self-centering when inserted into the pulmonary vein, because the tapered ablative structure 32 will wedge itself against the pulmonary vein ostium and the internal wall of pulmonary vein itself. Not only does this result in proper positioning of the electrodes 34, the wedging effect also prevents beating related movement of the heart from the knocking the ablation catheter 16 out of position once it is in place. The distal member 26 of the catheter body 24 also forms a distal anchoring structure 42, which allows the ablative structure 32 to be precisely located relative to the pulmonary vein. More specifically, advancing the anchoring structure 42 into the pulmonary vein aligns the ablative structure 32 with the pulmonary vein. In the illustrated embodiment, the anchoring structure 42 is simply the portion of the distal member 26 that is distal to the ablative structure 32. Alternatively, a separate structure may be secured to the distal end of the distal member 26. The exemplary anchoring structure 42 is approximately 1 to 2 inches in length, although other lengths may be used to suit particular applications. Referring to FIG. 3, the shape of the ablative structure 32 is achieved through the use of a center support 44 that is positioned inside of and passes within the length of the distal member 26. In the illustrated embodiment, the center support 44 is a rectangular wire formed from resilient inert wire, such as Nickel Titanium (commercially available under the trade name Nitinol) or 17-7 stainless steel wire, with a portion thereof heat set into the desired helical configuration. Alternatively, the center support 44 can be circular. The thickness of the rectangular center support 44 is preferably between about 0.010 inch and about 0.015 inch. Resilient injection molded plastic can also be used. Although other cross sectional configurations can be used, such as a round wire, a rectangular cross section arranged such that the longer edge extends in the longitudinal direction is preferred for at least the ablative structure 32. Such an orientation reduces the amount of torsional force, as compared to a round wire, required to unwind the ablative structure 32 into an expanded configuration and collapse the ablative structure 32 into a linear structure. The center support 44 is preferably housed in an insulative tube 46 formed from material such as Teflon�. or polyester. Additional details concerning the placement of a center support within the distal member of a catheter can be found in commonly assigned U.S. patent application Ser. No. 09/150,833, entitled �Catheter Having Improved Torque Transmission Capability and Method of Making the Same,� which is expressly incorporated herein by reference. Preferably, the distal portion of the distal member 26 is more flexible than the proximal portion of the distal member 26 in order to prevent tissue damage when attempts are made to insert the ablative structure 32 into a pulmonary vein. In addition, the ablative structure 32 will be more predisposed to easily uncoil for placement within the sheath 14, remain uncoiled and slide though the sheath 14 until it exits through the distal end of the sheath and re-coils, and then easily uncoil again when pulled back into the sheath after the procedure is completed. Also, the stiffer proximal portion of the distal member 26 allows the physician to press the ablation electrodes 34 against the tissue with more force when lesions are being created. The flexibility of the distal portion of the distal member 26 can be increased in variety of ways, e.g., by using a core wire (not shown) having a varying stiffness, or by constructing the distal member 26 from different materials. Further details on the construction of helical structures with varying flexibility are disclosed in U.S. patent application Ser. No. 09/832,612, entitled �Helical and Pre-Oriented Loop Structures for Supporting Diagnostic and Therapeutic Elements in Contact with Body Tissue,� which is expressly incorporated herein by reference. The ablation catheter 16 may comprise an optional stylet (not shown) that enables the physician to manipulate the ablative structure 32 and adjust its shape by longitudinally and/or rotating the stylet. Further details on the construction and use of the stilette, along with a handle assembly specifically designed to manipulate the stilette, are disclosed in U.S. patent application Ser. No. 09/832,612. The ablation catheter 16 comprises a lumen 48 (in addition to other lumens for providing ablation and signals wires described below) for slidably receiving the mapping catheter 18 (shown in FIG. 2). The lumen 48 proximally terminates in the handle assembly 31 at an insertion port 50 (shown in FIG. 1) and distally terminates in the distal member 26 at an exit port 52 (shown in FIG. 2) just proximal to the ablative structure 32. Thus, the mapping catheter 18 can be introduced into the insertion port 50 on the handle assembly 31, through the lumen 48, and out the exit port 52, so that it extends within an interior space 54 created by the ablative structure 32. The spaced ablation electrodes 34 are preferably in the form of wound, spiral coils. The coils are made of electrically conducting material, like copper alloy, platinum, or stainless steel, or compositions such as drawn-filled tubing (e.g. a copper core with a platinum jacket). The electrically conducting material of the coils can be further coated with platinum-iridium or gold to improve its conduction properties and biocompatibility. A preferred coil electrode is disclosed in U.S. Pat. No. 5,797,905, which is expressly incorporated herein by reference. The electrodes 34 are electrically coupled to individual wires 55 (shown in FIG. 3) to conduct coagulating energy to them. The wires are passed in conventional fashion through a lumen extending through the associated catheter body into a PC board (not shown) in the handle assembly 31, where they are electrically coupled to a connector (not shown) that is received in a port on the handle assembly 31. The connector plugs into the RF generator 20 (shown in FIG. 1). As an alternative, the ablation electrodes 34 may be in the form of solid rings of conductive material, like platinum, or can comprise a conductive material, like platinum-iridium or gold, coated upon the device using conventional coating techniques or an ion beam assisted deposition (IBAD) process. For better adherence, an undercoating of nickel or titanium can be applied. The electrodes 34 can also be in the form of helical ribbons. The electrodes 34 can also be formed with a conductive ink compound that is pad printed onto a nonconductive tubular body. A preferred conductive ink compound is a silver-based flexible adhesive conductive ink (polyurethane binder), however other metal-based adhesive conductive inks such as platinum-based, gold-based, copper-based, etc., may also be used to form electrodes 34. Such inks are more flexible than epoxy-based inks. The flexible electrodes 34 are preferably about 4 mm to about 20 mm in length. In the preferred embodiment, the electrodes are 12.5 mm in length with 1 mm to 3 mm spacing, which will result in the creation of continuous lesion patterns in tissue when coagulation energy is applied simultaneously to adjacent electrodes 34. For rigid electrodes 34, the length of the each electrode can vary from about 2 mm to about 10 mm. Using multiple rigid electrodes 34 longer than about 10 mm each adversely effects the overall flexibility of the device, while electrodes 34 having lengths of less than about 2 mm do not consistently form the desired continuous lesion patterns. The portion of the electrodes 34 that are not intended to contact tissue (and be exposed to the blood pool) may be masked through a variety of techniques with a material that is preferably electrically and thermally insulating. This prevents the transmission of coagulation energy directly into the blood pool and directs the energy directly toward and into the tissue. For example, a layer of UV adhesive (or another adhesive) may be painted on preselected portions of the electrodes 34 to insulate the portions of the electrodes not intended to contact tissue. Deposition techniques may also be implemented to position a conductive surface only on those portions of the assembly intended to contact tissue. Alternatively, a coating may be formed by dipping the electrodes 34 in PTFE material. The electrodes 34 can include a porous material coating, which transmits coagulation energy through an electrified ionic medium. For example, as disclosed in U.S. Pat. No. 5,991,650, electrodes 34 may be coated with regenerated cellulose, hydrogel or plastic having electrically conductive components. With respect to regenerated cellulose, the coating acts as a mechanical barrier between the surgical device components, such as electrodes, preventing ingress of blood cells, infectious agents, such as viruses and bacteria, and large biological molecules such as proteins, while providing electrical contact to the human body. The regenerated cellulose coating also acts as a biocompatible barrier between the device components and the human body, whereby the components can now be made from materials that are somewhat toxic (such as silver or copper). The electrodes 34 may be operated in a uni-polar mode, in which the soft tissue coagulation energy emitted by the electrodes 34 is returned through an indifferent patch electrode (not shown) externally attached to the skin of the patient. Alternatively, the electrodes 34 may be operated in a bi-polar mode, in which energy emitted by one or more electrodes 34 is returned through other electrodes 34. The amount of power required to coagulate tissue ranges from 5 to 150 W. Although ablation electrodes 34 have been described as the operative elements that create the lesion, other operative elements, such as lumens for chemical ablation, laser arrays, ultrasonic transducers, microwave electrodes, and ohmically heated hot wires, and such devices may be substituted for the electrodes 34. The ablation catheter 16 further comprises temperature sensors (not shown), such as thermocouples or thermistors, which may be located on, under, abutting the longitudinal end edges of, or in between, the electrodes 34. Preferably, the temperature sensors are located at the longitudinal edges of the electrodes 34 on the distally facing side of the ablative structure 32. In some embodiments, a reference thermocouple (not shown) may also be provided. For temperature control purposes, signals from the temperature sensors are transmitted to the source of coagulation energy by way of wires 60 (shown in FIG. 3) that are also connected to the aforementioned PC board in the handle assembly 31. Suitable temperature sensors and controllers which control power to electrodes based on a sensed temperature are disclosed in U.S. Pat. Nos. 5,456,682, 5,582,609 and 5,755,715. The mapping catheter 18 comprises a flexible catheter body 62 formed of a flexible spline composed of a resilient, biologically inert material, like Nitinol metal or silicone rubber. Thus, the mapping catheter body 62 is configured to bend and conform to the endocardial and pulmonary vein tissue surface its contacts. In the illustrated embodiment, the diameter of the mapping catheter body 62 is relatively small (e.g., 3-4 F), so that the ablation catheter 16 that houses the mapping catheter 18 assumes a small profile. The distal end of the mapping catheter body 62 forms a mapping structure 64. The mapping catheter 18 comprises mapping electrodes 58 extending along the mapping structure 64. In the illustrated embodiment, the mapping electrodes 58 are ring electrodes that are composed of a solid, electrically conducting material, like platinum or gold, attached about the catheter body 62. Alternatively, the mapping electrodes 58 can be formed by coating the exterior surface of the catheter body 62 with an electrically conducting material, like platinum or gold. The coating can be applied using sputtering, ion beam deposition, or equivalent techniques. The mapping electrodes 58 can have suitable lengths, such as between 0.5 and 5 mm. In use, the mapping electrodes 58 sense electrical events in myocardial tissue for the creation of electrograms, and are electrically coupled to the mapping processor 22 (see FIG. 1). A signal wire (not shown) is electrically coupled to each mapping electrode 58. The wires extend through the catheter body 62 into an external multiple pin connector 66. The connector 66 electrically couples the mapping electrodes 58 to the mapping processor 22. As illustrated in FIG. 2, the mapping structure 64 extends distally within an interior space 54 of the ablative structure 32, and is curved in an undulated fashion that will resiliently place the mapping electrodes 58 in contact with the tissue of the vessel in which the ablation and mapping catheters 16 and 18 are placed. Specifically, the total transverse distance that the mapping structure 64 curves is greater than the diameter of the selected vessel, so that placement of the mapping structure 64 within the vessel will cause the vessel wall to provide a compressive force mapping structure 64, thereby resiliently lodging the mapping structure 64 within the vessel. In the illustrated embodiment, the mapping structure 64 comprises first and second curved sections 68 and 70 having apexes that point in the same direction away from the longitudinal axis of the ablation catheter 16, and an mediate curved section 72 between the proximal and distal curved sections 68 and 70 having an apex that points towards the longitudinal axis of the ablation catheter 16. In this manner, when the mapping structure 64 is deployed from the exit port 52 of the ablation catheter lumen 48, the proximal curved section 68 may come in contact with tissue between the proximal and medial coils 36 and 38 of the ablative structure 32, and the distal curved section 70 may come in contact with tissue between the mediate and distal coils 38 and 40 of the ablative structure 32. The medial curved section 72 provides clearance between the mapping structure 64 and the medial coil 38 of the ablative structure 32. The distal end of the mapping catheter body 62 further forms a straight distal section 74 that is configured to stabilize the mapping structure 64 by contacting the portion of the vessel wall opposite the portion in which the proximal and distal curved sections 68 and 70 contact. Preferably, the distal section 74 is floppy, similar to the tip of a guidewire, thereby minimizing tissue trauma. It should be noted that although the mapping catheter body 62 has been described as a linear resilient spline, the catheter body 62 can also have other shapes, such as, e.g., a spiral, basket, etc., that allow the mapping catheter body 62 to collapse into the lumen 48 of the ablation catheter body 62. Having described the structure of the treatment system 10, its operation in creating a circumferential lesion within the ostium of a pulmonary vein, thereby electrically isolating it from the left atrium of the heart, will now be described with reference to FIGS. 4-6. It should be noted that the views of the heart 200 and other interior regions of the body described herein are not intended to be anatomically accurate in every detail. The Figures show anatomic details in diagrammatic form as necessary to show the features of the embodiment described herein. Referring specifically to FIG. 4, the guide sheath 14 is introduced into the left atrium 202 of the heart 200, so that the distal end of the sheath 14 is adjacent a selected pulmonary vein 204. Introduction of the guide sheath 14 within the left atrium 202 can be accomplished using a conventional vascular introducer retrograde through the aortic and mitral valves, or can use a transeptal approach from the right atrium. A guide catheter or guide wire (not shown) may be used in association with the guide sheath 14 to aid in directing the guide sheath 14 through the appropriate artery toward the heart 200. Once the distal end of the guide sheath 14 is properly placed, the ablation catheter 16 is introduced through the guide sheath 14 until the ablative structure 32 is deployed from the guide sheath 14. The ablation catheter 16 is then manipulated, so that the anchoring structure 42, and then the ablative structure 32, is placed inside the ostium 206 of the pulmonary vein 204, as illustrated in FIG. 5. The resiliency of the ablative structure 32 places the ablation electrodes 34 in firm and stable contact with the wall of the pulmonary vein 204. For purposes of illustration, the ablative structure 32 is shown disposed well within the pulmonary vein 24. In practice, however, the entire ablative structure 32 will engage the portion of the pulmonary vein 204 just distal to the ostium 206. The mapping catheter 18 is then introduced into the entry port 50 on the handle assembly 31, through the lumen 48 of the ablation catheter 16 until the mapping structure 64 is deployed out from the exit port 52 into the interior space 54 formed by the ablative structure 32. Introduction of the mapping catheter 18 within the lumen 48 of the ablation catheter 16 can either be accomplished prior to or subsequent to the introduction of the ablation catheter 16 within the left atrium 202 of the heart 200. As illustrated in FIG. 5, the mapping structure 64 is placed firmly in contact with the tissue inside the pulmonary vein 204. Specifically, the proximal and medial curved sections 68 and 70 of the mapping structure 64 are isolaterally in contact along the wall of the pulmonary vein 204, and the distal straight section 74 is contralaterally in contact along the wall of the pulmonary vein 204. As a result, the electrodes 58 of the mapping structure 64 will be firmly and stably in contact with the tissue. Once this electrode contact has been achieved, the mapping processor 22 is operated in order to obtain and record ECG signals from the pulmonary vein tissue. As described below, these ECG signals will be compared with the ECG signals obtained subsequent to an ablation procedure in order to determine if the resultant lesion has successfully electrically isolated the pulmonary vein 204 from the left atrium 202 of the heart 200. One the pre-ablation ECG signals have been obtained and recorded, the RF generator 20 is operated in order to convey RF energy to the ablation electrodes 34. In the illustrated embodiment, the RF energy is conveyed to the electrodes 34 one at a time. Thus, assuming that there are six ablation electrodes 34, six ablation procedures are performed in order to create a circumferential lesion around the wall of the pulmonary vein 204. Alternatively, the RF energy is simultaneously conveyed to all six electrodes 34. In this manner, a single ablation procedure is performed in order to create the circumferential lesion. In either case, the ablation electrodes 34 need not be moved during the ablation procedure(s). After the lesion has been created, the mapping processor 22 is again operated to obtain and record ECG signals from the pulmonary vein 204. These post-ablation ECG signals are compared to the pre-ablation ECG signals to determine whether the circumferential lesion has completely isolated the pulmonary vein 204 from the left atrium 202 of the heart 200. The mapping structure 64 can be rotated or otherwise moved in order to obtain and record ECG signals on other regions of the pulmonary vein 204. Once proper ablation has been confirmed, the guide sheath 14, ablation catheter 16, and mapping catheter 18 are removed from the patient's body, or alternatively, are used to create a circumferential lesion within another pulmonary vein. Referring now to FIG. 7, an alternative embodiment of a catheter assembly 112 that can be used in the treatment system 10 of FIG. 1 is shown. The catheter assembly 112 is similar to the previously described catheter assembly 12, with the exception that the ablation catheter body forms a loop-shaped, rather than a helically-shaped, ablative structure. Specifically, an ablation catheter 116 comprises a flexible elongate catheter body 124 having a distal member 126 that forms a loop-shaped ablative structure 132. The ablation catheter 116 further comprises a pull wire 134, which extends from the tip of the distal member 126 back through the sheath 32. The pull wire 134 is used to pull the distal member 116 into a loop configuration. The pull wire 134 also maintains the shape of the ablative structure 132 (thereby insuring good tissue contact) when the loop structure 132 is urged against tissue, such as a pulmonary vein ostium. In the illustrated embodiment, the ablative structure 132 forms a curved portion with a radius of about 0.5 inch. The curved portion lies in a plane between about 30 and about 60 degrees, and preferably about 45 degrees, out of the horizontal catheter plane, as illustrated in FIG. 8. The preset curvature may be accomplished in a variety of ways. Preferably, the curved portion is preset through the use of a thermal forming technique (100� C. for 1 hour). The preset curvature may also be accomplished through the use of a pre-shaped core wire (not shown) formed from Nitinol or 17-7 stainless steel. The curved portion will typically be bent out of its pre-bent orientation when the ablative structure 132 is urged against tissue (note the dashed lines in FIG. 8). As a result, a spring force that urges the ablative structure 132 against the tissue is generated, thereby improving tissue/electrode contact. The pull wire 134 is preferably a flexible, inert cable constructed from strands of metal wire material, such as Nitinol or 17-7 stainless steel, that is about 0.012 inch to about 0.025 inch in diameter. Alternatively, the pull wire 134 may be formed from a flexible, inert stranded or molded plastic material. The pull wire 134 is also preferably round in cross-section, although other cross-sectional configurations can be used. Further details on the construction of loop-shaped ablative structures and pull wires are disclosed in U.S. patent application Ser. No. 09/832,612, which has previously been incorporated herein by reference, and U.S. Pat. No. 6,048,329, which is expressly incorporated herein by reference. The catheter assembly 112 further comprises a mapping catheter 118 that includes a catheter body 164 with a mapping structure 164 that extends distally through an interior space 156 of the ablative structure 132. The mapping structure 164 is similar to the previously described mapping structure 64, with the exception that is forms a single curve that will extend along one side of the pulmonary vein contralaterally to a straight distal section 174. Having described the structure of the treatment system 110, its operation in creating a circumferential lesion around the ostium of a pulmonary vein, thereby electrically isolating it from the left atrium of the heart, will now be described with reference to FIGS. 9-11. Once the guide sheath 14 has been properly placed within the left atrium 202 of the heart 200, as described above with reference to FIG. 4, the ablation catheter 116 is introduced through the guide sheath 14 until the ablative structure 132 is deployed from the guide sheath 14, as illustrated in FIG. 9. The ablative structure 132 is placed into a loop-shaped by pulling the pull wire 134, and the mapping catheter 118 is then introduced into the entry port 50 on the handle assembly 31 (shown in FIG. 1), through the lumen of the ablation catheter 116 until the mapping structure 164 is deployed out from the exit port 52 through the interior space 154 formed by the ablative structure 132, as illustrated in FIG. 10. As previously mentioned, introduction of the mapping catheter 118 within the lumen of the ablation catheter 116 can either be accomplished prior to or subsequent to the introduction of the ablation catheter 116 within the left atrium 202 of the heart 200. Notably, the distal section 174 of the mapping catheter 118 is located within the ostium 206 of the pulmonary vein 204, so that it can be guided within the pulmonary vein 204 as the ablative structure 132 is advanced towards the ostium 206. Once the distal section 174 of the mapping catheter 118 is definitively within the pulmonary vein 204, the ablative structure 132 is placed against the ostium 206 of the pulmonary vein 204, so that it circumscribes the ostium 206, as illustrated in FIG. 11. The resiliency of the ablative structure 132 places the ablation electrodes 34 in firm and stable contact with the ostium 206. The mapping structure 164 is placed firmly in contact with the tissue inside the pulmonary vein 204. Specifically, the mapping structure 164 is placed in contact along the wall of the pulmonary vein 204, and the distal straight section 174 is placed contralaterally in contact along the wall of the pulmonary vein 204. In a similar manner previously described, the mapping processor 22 is operated to obtained pre- and post-ablation ECG signals, and the RF generator 20 is operated to create a circumferential lesion around the ostium 226 of the pulmonary vein 204. Referring now to FIGS. 12 and 13, another alternative embodiment of a catheter assembly 212 that can be used in the treatment system 10 of FIG. 1 is shown. The catheter assembly 212 is similar to the previously described catheter assembly 12, with the exception that an expandable-collapsible ablative structure, rather than a helically-shaped ablative structure, is formed at the distal end of the ablation catheter body. Specifically, an ablation catheter 216 comprises a flexible elongate catheter body 224 having a distal member 226 on which there is mounted an expandable-collapsible ablative structure 232. The ablative structure 232 is formed by a �balloon-like� wall suitably bonded to and disposed about the distal member 226. The geometry of the ablative structure 232 can be altered between a collapsed, low profile geometry (FIG. 12), and an expanded, high profile geometry (FIG. 13). The ablation catheter body 224 comprises inflation and venting lumens (not shown) that extend from a handle assembly (not shown) to the interior region of the ablative structure 232. The catheter body 224 comprises a lumen (not shown) that terminates in an exit port 252 out which the previously described mapping structure 164 of the mapping catheter 118 extends. The exit port 252, in this case, is distal to the ablative structure 232. In order to inflate the ablative structure 232, a liquid inflation medium, such as water, saline solution, or other bio-compatible fluid, is conveyed under positive pressure through a port on the handle assembly, through the inflation lumen extending through the catheter body 224. The liquid medium fills the interior of the ablative structure 232 and exerts pressure on the inside of the ablative structure 232 to urge the ablative structure from its collapsed geometry (FIG. 12) to its expanded geometry (FIG. 13). Constant exertion of pressure through the inflation lumen maintains the ablative structure 232 in its expanded geometry. The venting lumen is used to vent any air or excess fluid from the ablative structure 232. Alternatively, the inflating fluid medium can comprise a gaseous medium, such as carbon dioxide. Preferably, the ablative structure 232 is less than 8 French diameter when in a collapsed geometry for ease of manipulation through the vasculature, and about 2.0 cm in circumference around its largest portion when in its expanded geometry and located in a desired ablation region within the pulmonary vein. The ablative structure 232 is preferably made of a suitable biocompatible, thermoplastic or elastomeric material, and can be configured to have any one of many shapes in its expanded geometry, such as the shape shown in FIG. 13, depending on the desired resulting geometry. Proximate the center of the ablative structure 232 is a pronounced circumferential region 236 having a larger circumference than that of the rest of the ablative structure 232. In this manner, expansion of the ablative structure 232 within the pulmonary vein provides a force that is concentrated between the enlarged circumferential region 236 and the interior surface of a pulmonary vein in which the ablative structure 232 is situated, thus enhancing the lesion creating characteristics of the ablative structure 232. The ablation catheter 216 comprises an electrode that takes the form of a conductive shell 234 made of a material having a relatively high electrical and thermal conductivity that is suitably deposited on the outer surface of the ablative structure 232 over the enlarged circumferential region 236 using ion deposition or equivalent techniques. Materials possessing these characteristics include, among others, gold, platinum, platinum/iridium, conductive ink epoxy, or a combination thereof. In particular, noble metals are preferred. The area of the ablative structure 232 located immediately proximal and distal to the enlarged circumferential region 236 is preferably masked prior to the deposition of the conductive material, so that resulting non-conductive regions 238 and 240 are formed on either side of the conductive shell 234. In particular, the masking of the regions on either side on the conductive region assures that the maximum current density will be distributed at the enlarged circumferential region 236 of the ablative structure 232, thereby allowing the ablative structure 232 to efficiently form annular lesions within the pulmonary vein. In order to deliver current, the conductive shell 234 is coupled to a plurality of insulated ablation wires (not shown), that are in turn coupled to the handle assembly (not shown). There are many modifications that can be made to the ablative structure 232. For example, the conductive shell 234 may be segmented instead of continuous. The ablative structure 232 may be microporous, allowing ions to pass from an interior electrode, through the pores, into the tissue. The ablative structure 232 may have an interior support structure (such as resilient splines or mesh or a foam substance) arranged to apply an outward force against the electrode structure 232 to augment, or replace, the outward force caused by a pressurized liquid medium. The ablative structure 232 may comprise blood lumens for allowing the flow of blood through the ablative structure 232 when expanded within the pulmonary vein. The ablative structure 232 may be shaped, such that a portion of the conductive shell 234 engages the ostium of the pulmonary vein. Other types of ablative structures, besides balloon-like ablative structures, can be envisioned. For example, a basket-type ablative structure having a plurality of resilient splines with ablation electrodes mounted thereon can be used to create a circumferential lesion within the pulmonary vein. Pre-shaped ablative loop structures that are either coplanar with, or orthogonal to, the longitudinal axis of the catheter body can also be used to create lesions within or around the pulmonary vein. The details regarding the ablative structure 232, as well as many other structures designed to create lesions in and around the pulmonary veins are disclosed in U.S. patent application Ser. No. 08/984,414, which is expressly incorporated herein by reference. In each case, a lumen for housing the mapping catheter 118, and an exit port out which the mapping electrode structure 164 extends, can be incorporated into the design. Having described the structure of the treatment system 210, its operation in creating a circumferential lesion around the ostium of a pulmonary vein, thereby electrically isolating it from the left atrium of the heart, will now be described with reference to FIGS. 14-16. Once the guide sheath 14 has been properly placed within the left atrium 202 of the heart 200 adjacent the ostium 206 of the selected pulmonary vein 204, as described above with reference to FIG. 4, the ablation catheter 216, while the ablative structure 232 is in its collapsed state, is introduced through the guide sheath 14 until the ablative structure 232 is deployed from the guide sheath 14 and into the ostium 206 of the pulmonary vein 204, as illustrated in FIG. 14. The ablative structure 232 is then is placed into its expanded geometry by conveying the inflation medium into the interior of the ablative structure 232, so that the enlarged circumferential region 236 is circumferentially placed firmly in contact with the inner wall of the pulmonary vein 204, as illustrated in FIG. 15. The mapping catheter 118 is then introduced through the lumen of the ablation catheter 216 until the mapping structure 164 is deployed out from the exit port 252. As previously mentioned, introduction of the mapping catheter 118 within the lumen of the ablation catheter 216 can either be accomplished prior to or subsequent to the introduction of the ablation catheter 216 within the left atrium 202 of the heart 200. As illustrated in FIG. 16, the mapping structure 164 is placed firmly in contact with the tissue inside the pulmonary vein 204. Specifically, the mapping structure 164 is placed in contact along the wall of the pulmonary vein 204, and the distal straight section 174 is placed contralaterally in contact along the wall of the pulmonary vein 204. In a similar manner previously described, the mapping processor 22 is operated to obtain pre- and post-ablation ECG signals, and the RF generator 20 is operated to create a circumferential lesion within the pulmonary vein 204. In all of the previously described embodiments, the mapping catheters have been introduced through lumens contained within the ablation catheters. Alternatively, as illustrated in FIG. 17, the ablation catheter 16 and mapping catheter 18 can be independently introduced through the lumen of the guide sheath 14. Thus, the steps used to create a circumferential lesion within the pulmonary vein 204 using this assembly will be the same as that described with respect to FIGS. 4-6, with the exception that the mapping catheter 18 will be introduced through the lumen of the guide sheath 14, rather than a lumen within the ablation catheter 16. Although particular embodiments of the present invention have been shown and described, it will be understood that it is not intended to limit the present invention to the preferred embodiments, and it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention. Thus, the present inventions are intended to cover alternatives, modifications, and equivalents, which may be included within the spirit and scope of the present invention as defined by the claims. Referenced byCiting PatentFiling datePublication dateApplicantTitleUS7662150Apr 27, 2005Feb 16, 2010Boston Scientific Scimed, Inc.Variable size apparatus for supporting diagnostic and/or therapeutic elements in contact with tissueUS7914527 *Aug 17, 2006Mar 29, 2011Terumo Kabushiki KaishaEnergy based devices and methods for treatment of patent foramen ovaleUS7988690 *Jan 27, 2005Aug 2, 2011W.L. Gore & Associates, Inc.Welding systems useful for closure of cardiac openingsUS8409191Nov 4, 2004Apr 2, 2013Boston Scientific Scimed, Inc.Preshaped ablation catheter for ablating pulmonary vein ostia within the heartUS8469950Feb 3, 2008Jun 25, 2013Cardionova Ltd.Intra-atrial apparatus and method of use thereofUS8535303May 5, 2006Sep 17, 2013Boston Scientific Scimed, Inc.Preshaped localization catheter, system, and method for graphically reconstructing pulmonary vein ostiaUS8657815Feb 6, 2008Feb 25, 2014Microcube, LlcDelivery system for delivering a medical device to a location within a patient's bodyUS8702696Jan 28, 2010Apr 22, 2014Boston Scientific Scimed, Inc.Variable size apparatus for supporting diagnostic and/or therapeutic elements in contact with tissueUS8784414Sep 17, 2013Jul 22, 2014Boston Scientific Scimed, Inc.Preshaped localization catheter, system, and method for graphically reconstructing pulmonary vein ostiaEP1896107A1 *Jun 23, 2006Mar 12, 2008Cathrx LtdCatheter shape forming systemEP2341974A1 *Oct 30, 2009Jul 13, 2011Cathrx LtdA catheter assemblyWO2006115683A1 *Mar 29, 2006Nov 2, 2006Boston Scient Scimed IncVariable size apparatus for supporting diagnostic and/or therapeutic elements in contact with tissueWO2007030433A2 *Sep 6, 2006Mar 15, 2007Nmt Medical IncRemovable intracardiac rf deviceWO2008099380A2 *Feb 3, 2008Aug 21, 2008Cardionova LtdIntra-atrial apparatus and method of use thereofWO2010048676A1Oct 30, 2009May 6, 2010Cathrx LtdA catheter assemblyWO2013028993A2 *Aug 24, 2012Feb 28, 2013Boston Scientific Scimed, Inc.Device and methods for nerve modulationWO2014036163A1 *Aug 28, 2013Mar 6, 2014Boston Scientific Scimed, Inc.Renal rf ablation system with a movable virtual electrode and related methods of use* Cited by examinerClassifications U.S. Classification606/41, 600/374, 600/381International ClassificationA61B17/00, A61B18/14Cooperative ClassificationA61B2018/00214, A61B2018/1435, A61B2018/0022, A61B18/1492, A61B2017/00243, A61B2018/00375, A61B2017/00044, A61B2018/00839European ClassificationA61B18/14VLegal EventsDateCodeEventDescriptionMar 14, 2012FPAYFee paymentYear of fee payment: 4Nov 6, 2006ASAssignmentOwner name: BOSTON SCIENTIFIC SCIMED, INC., MINNESOTAFree format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;REEL/FRAME:018505/0868Effective date: 20050101Owner name: BOSTON SCIENTIFIC SCIMED, INC.,MINNESOTAFree format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100203;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100209;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100216;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100223;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100302;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100309;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100316;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100323;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100330;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100406;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100413;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100420;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100504;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100511;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100518;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;US-ASSIGNMENT DATABASE UPDATED:20100525;REEL/FRAME:18505/868Free format text: CHANGE OF NAME;ASSIGNOR:SCIMED LIFE SYSTEMS, INC.;REEL/FRAME:18505/868Sep 26, 2003ASAssignmentOwner name: SCIMED LIFE SYSTEMS, INC., MINNESOTAFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:TAIMISTO, MIRIAM H.;KOBLISH, JOSEF V.;REEL/FRAME:014551/0637Effective date: 20030923RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google