# US 5,100,388 A · Method and device for thermal ablation of hollow body organs > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,100,388 A - Document ID: US5100388A - Status: Granted - Kind: A - Application number: 07/529,077 - Filed: 1990-05-25 - Granted: 1992-03-31 - Earliest claimed: 1989-09-15 - Assignees: Interventional Thermodynamics, Inc. - Inventors: Robert S. Behl; Colin J. Nichols - Web page: https://patentgrep.com/patent/US5100388A ## CPC - A61B 18/082: {Probes or electrodes therefor} - A61B 18/28: for heating a thermal probe or absorber - A61B 2017/22054: {with two balloons} - A61B 2018/00095: {high, i.e. heat conducting} - A61B 2018/046: {in liquid form} - A61B 2090/3933: {Liquid markers} - A61B 2090/3962: {palpable} - A61B 2218/002: Irrigation - A61F 2007/0298: {with a section for heating and a section for cooling} - A61M 3/0279: {Cannula; Nozzles; Tips; their connection means} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} ## Abstract Hollow body organs, such as the gallbladder, may be ablated by introducing a substantially unheated thermally conductive medium to the interior of the organ. The thermally conductive medium is then heated to a temperature sufficient to necrose the endothelial lining or mucous membrane of the organ. After the lining or membrane has necrosed, the interior of the organ will fibrose over time and the organ will eventually be resorbed by the body. A catheter useful in performing the ablation method comprises an elongate member having a heating element at its distal tip. The catheter will include at least one lumen for delivering the thermally conductive medium to the interior of the hollow body organ, and the heating means is used to raise the temperature of the thermally conductive medium after it has been delivered. Optionally, the catheter may include one or more inflatable balloons which facilitate sealing of the hollow body organ to inhibit leakage of the thermally conductive medium during the treatment process. The heating element may comprise a single point heat source or a heat source distributed over a fixed length. Distributed heat sources may further be adapted to provide for a non-linear heat flux delivery pattern. ## Claims ### Claim 1 A thermal ablation catheter, said catheter comprising: a flexible elongate member having proximal and distal ends; means for heating an unconstrained environment surrounding the catheter, said heating means comprising a resistive heating element which is exposed directly to the environment over a predetermined length of the elongate member and which is capable of conforming to flexure of the elongate member; and a pair of conductors extending from the proximal end of the flexible elongate member to the resistive heating element, whereby the resistive heating element may be connected in a circuit to a power supply. ### Claim 2 (depends on 1) A thermal ablation catheter as in claim 1, further comprising a first means on the flexible elongate member for sealing a duct. ### Claim 3 (depends on 2) A thermal ablation catheter as in claim 2, wherein said sealing means is disposed proximally on the heating means. ### Claim 4 (depends on 2) A thermal ablation catheter as in claim 2, wherein said sealing means is disposed distally of the heating means. ### Claim 5 (depends on 2) A thermal ablation catheter as in claim 2, further comprising a second means for sealing a duct disposed on the flexible elongate member, wherein the first and second sealing means are located on opposite sides of the heating means. ### Claim 6 (depends on 1) A thermal ablation catheter as in claim 1, wherein the heating means extends over a predetermined length of at least about 3 mm. ### Claim 7 (depends on 6) A thermal ablation catheter as in claim 6, wherein the heating means is formed substantially continuously over said predetermined length. ### Claim 8 (depends on 6) A thermal ablation catheter as in claim 6, wherein the heating means is discontinuously distributed over said axial length. ### Claim 9 (depends on 2) A thermal ablation catheter as in claim 2, wherein at least a portion of the length of the heating means is disposed within the first sealing means. ### Claim 10 (depends on 6) A thermal ablation catheter as in claim 6, wherein the heating means provides a non-linear heat flux pattern along its predetermined length, said pattern being selected to provide a desired heating profile within the fluid environment. ### Claim 11 (depends on 10) A thermal ablation catheter as in claim 10, wherein the heating means includes at least two spaced-apart discrete heating elements, wherein the spacing is selected to provide a desired heating pattern. ### Claim 12 (depends on 1) A thermal ablation catheter as in claim 1, wherein the heating means includes a coil wrapped about the exterior of the elongate member over said predetermined length. ### Claim 13 (depends on 12) A thermal ablation catheter as in claim 12, wherein the pitch of the coil is varied along the length of the elongate member in order to provide a non-linear heat flux pattern selected to provide a desired heating profile within the fluid environment. ### Claim 14 A thermal ablation catheter comprising: a flexible elongate member having proximal and distal ends; and a heating coil wrapped externally over a predetermined length of the elongate member near its distal end wherein the spacing between adjacent winding of the coil is varied in order to provide a preselected non-linear heat flux pattern. ### Claim 15 (depends on 14) A thermal ablation catheter as in claim 14, wherein the predetermined length is in the range from about 3 mm to 6 cm. ### Claim 16 (depends on 14) A thermal ablation catheter as in claim 14 further comprising a first inflatable balloon on the flexible elongate member for sealing a duct and a means on the elongate member for selectively inflating said balloon. ### Claim 17 (depends on 16) A thermal ablation catheter as in claim 16, wherein the first inflatable balloon is disposed distally of the heating coil. ### Claim 18 (depends on 16) A thermal ablation catheter as in claim 16, wherein the first inflatable balloon is disposed proximally of the heating coil. ### Claim 19 (depends on 16) A thermal ablation catheter as in claim 16, further comprising a second inflatable balloon on a side of the heating coil opposite to that of the first inflatable balloon. ### Claim 20 (depends on 16) A thermal ablation catheter as in claim 16, further comprising means for heating an inflation medium within the inflatable balloon. ### Claim 21 (depends on 16) A thermal ablation catheter as in claim 16, wherein the means for heating comprises a portion of the heating coil which extends beneath the inflatable balloon. ### Claim 22 A thermal ablation catheter, said catheter comprising: an elongate member having proximal and distal ends; means on the elongated member for introducing an unconstrained thermally conductive medium into a fluid environment surrounding the distal end of the elongate member; and means on the elongate member for heating the unconstrained thermally conductive medium in the fluid environment surrounding the distal end of the elongate member to a temperature sufficient to destroy tissue in contact with the unconstrained medium. ### Claim 23 (depends on 47) A catheter as in claim 47, wherein the elongate member is flexible. ### Claim 24 (depends on 22) A catheter as in claim 22, wherein the means for heating the fluid environment comprises a convective heating element exposed to said fluid environment and means for raising the surface temperature of the heating element. ### Claim 25 (depends on 49) A catheter as in claim 49, wherein the convective heating element is a resistive heating element and the means for raising the surface temperature includes circuitry for supplying current to the resistive heating element. ### Claim 26 (depends on 49) A catheter as in claim 49, wherein the convective heating element is a heat conductive block and the means for raising the surface temperature includes an optical waveguide for supplying radiation to heat the block. ### Claim 27 (depends on 24) A catheter as in claim 24, further comprising an axial passage in the convective heating element and an axial lumen in the elongate member, wherein the axial passage in the heating element is contiguous with the axial lumen in the elongate member. ### Claim 28 (depends on 47) A catheter as in claim 47, wherein the means for heating includes a radiofrequency generator. ### Claim 29 (depends on 28) A catheter as in claim 28, wherein the radiofrequency generator for heating is a microwave generator. ### Claim 30 (depends on 47) A catheter as in claim 47, further comprising a cage surrounding the means for heating to prevent direct contact of the means for heating with the interior of a hollow body organ while allowing substantially unrestricted exposure of the means for heating to the surrounding fluid environment. ### Claim 31 (depends on 47) A catheter as in claim 47, further comprising first means at the distal end for sealing a duct which could otherwise drain fluid from the hollow body organ. ### Claim 32 (depends on 31) A catheter as in claim 31, further comprising means for heating the duct sealing means. ### Claim 33 (depends on 56) A catheter as in claim 56, wherein the sealing means is an inflatable balloon and the catheter further comprises a means on the elongate member for selectively inflating said balloon. ### Claim 34 (depends on 58) A catheter as in claim 58, further comprising means for heating an inflation medium within the inflatable balloon. ### Claim 35 (depends on 22) A catheter as in claim 22, wherein the means for introducing an unconstrained thermally conductive medium is a lumen which directs the medium past the means for heating and into the fluid environment. ### Claim 36 (depends on 47) A catheter as in claim 47, further comprising means for aspirating fluid from the fluid environment surrounding the distal end of the elongate member. ### Claim 37 A thermal ablation catheter, said catheter comprising: a flexible elongate member having proximal and distal ends; a first inflatable balloon disposed about the elongate member near its distal end; means on the elongate member for selectively inflating the balloon; means on the elongate member for introducing a thermally conductive medium to a fluid environment surrounding the distal end of the elongate member, said introducing means being disposed on one side of the inflatable balloon; and means for heating the thermally conductive medium in the fluid environment surrounding the distal end of the elongate member, said heating means being disposed on the same side of the first balloon as is the introducing means and being capable of conforming to flexure of the elongate member. ### Claim 38 (depends on 37) A thermal ablation catheter as in claim 37, further comprising at least one additional inflatable balloon disposed on a side of the heating means opposite to that of the introducing means and the first inflatable balloon. ### Claim 39 (depends on 37) A thermal ablation catheter as in claim 37, wherein the heating means includes at least one discrete heating element disposed proximally to the first balloon. ### Claim 40 (depends on 37) A thermal ablation catheter as in claim 37, wherein the heating means includes at least one discrete heating element disposed distally to the first balloon. ### Claim 41 (depends on 37) A thermal ablation catheter as in claim 37, wherein the heating means provides a non-linear heat flux pattern over a predetermined axial length, said pattern being selected to provide a desired heating profile within the fluid environment. ### Claim 42 (depends on 41) A thermal ablation catheter as in claim 41, wherein the predetermined axial length of the heating means is in the range from about 3 mm to 6 cm. ### Claim 43 (depends on 37) A thermal ablation catheter as in claim 37, wherein the heating means includes a plurality of spaced-apart heating elements, wherein the spacing is selected to provide a desired heating pattern. ### Claim 44 (depends on 37) A thermal ablation catheter as in claim 37, wherein the heating means includes a coil wrapped about the exterior of the elongate member. ### Claim 45 (depends on 44) A thermal ablation catheter as in claim 44, wherein the pitch of the coil is varied along the length of the elongate member in order to provide a non-linear heat flux pattern over a predetermined axial length. ### Claim 46 A method for ablating a hollow body organ having at least one connecting duct, said method comprising the following steps performed in a predetermined order: sealing the connecting duct; introducing a thermally conductive medium into the hollow body organ; heating a portion of the connecting region to a temperature and for a time sufficient to destroy the endothelial lining or mucosa of said portion; and heating the thermally conductive medium within the hollow body organ to a temperature and for a time sufficient to destroy the endothelial lining mucosa of the hollow body organ. ### Claim 47 (depends on 46) A method as in claim 46, wherein heating of the connecting region is performed prior to heating of the hollow body organ. ### Claim 48 (depends on 46) A method as in claim 46, wherein heating of the connecting duct and heating of the hollow body organ are performed substantially simultaneously. ### Claim 49 (depends on 46) A method as in claim 46, wherein heating of the connecting duct is performed after introducing the thermally conductive medium but prior to heating the thermally conductive medium within the hollow body organ. ### Claim 50 (depends on 46) A method as in claim 46, further comprising introducing a thermally conductive medium into the connecting duct prior to introducing the medium into the hollow body organ. ### Claim 51 (depends on 50) A method as in claim 50, wherein thermally conductive medium is introduced substantially simultaneously to both the connecting duct and the hollow body organ after the connecting duct is sealed. ### Claim 52 (depends on 50) A method as in claim 50, wherein thermally conductive medium is introduced to the connecting duct prior to heating the connecting duct and is introduced to the hollow body organ thereafter, followed by heating of the hollow body organ. ### Claim 53 (depends on 46) A method as in claim 46, wherein sealing of the connecting region includes inflating a balloon to occlude the connecting duct. ### Claim 54 (depends on 53) A method as in claim 53, wherein heating of the connecting duct includes heating of an inflation medium within the balloon. ### Claim 55 (depends on 53) A method as in claim 53, wherein the inflation medium is heated to a temperature in the range from about 45.degree. C. to 120.degree. C. ### Claim 56 (depends on 53) A method as in claim 53, wherein a region of the connecting duct proximal to the balloon is heated. ### Claim 57 (depends on 46) A method as in claim 46, wherein the thermally conductive medium is substantially unheated when introduced into the hollow body organ. ### Claim 58 (depends on 46) A method as in claim 46, wherein the thermally conductive medium is heated to a temperature in the range from about 45.degree. C. to 120.degree. C. for a time in the range from about 1 minute to 60 minutes. ### Claim 59 (depends on 57) A method as in claim 57, wherein the hollow body organ is the gallbladder and the connecting duct is the cystic duct.