Systems and methods for RF ablation using jet injection of a conductive fluid
A method of preparing and ablating heart tissue includes a pre-treatment step of delivering a jet of conductive fluid to a portion of heart tissue. The conductive fluid is delivered using an injection device such as a hand-held jet injector, probe, or catheter. After injecting the heart tissue with the conductive fluid, RF energy is delivered to the site of the injection to form a lesion. The method enables a physician to produce large and accurately placed lesions within the treated tissue.
1 - 12 . (Cancelled).
13 . A method for ablating tissue comprising the steps of:
providing an injector device adjacent to a portion of the tissue, the injector device including a plurality of ports and a plurality of electrodes; and
injecting the tissue with a jet of conductive fluid from the injector device, the jet of conductive fluid entering the tissue via the plurality of ports; and
applying RF energy to the tissue containing the injected conductive fluid using the plurality of electrodes so as to form a lesion.
14 . The method according to claim 13 , wherein during the step of applying RF energy, the maximum temperature of the tissue is maintained below 100° C.
15 . The method according to claim 13 , further comprising the step of cooling the electrode during the step of applying RF energy.
16 . The method according to claim 13 , wherein the step of injecting is performed at a pressure within the range of about 500 psi to about 1500 psi.
17 . The method according to claim 13 , wherein the conductive fluid is a solution selected from the group consisting of sodium chloride, potassium chloride, sodium bicarbonate, sodium citrate, and potassium citrate.
18 . The method according to claim 13 , wherein the conductive fluid comprises an ionic radiographic contrast material.
19 . The method according to claim 13 , wherein the conductive fluid contains a dye.
20 . The method according to claim 13 , wherein after application of the RF energy a legion is formed having a depth of with the range of about 1 mm to about 10 mm.
21 . A device for injecting a conductive solution into tissue comprising:
source of pressurized gas;
a syringe having at least one nozzle at one end thereof, the source of pressurized gas being in fluid communication with a plunger contained within the syringe;
a conductive fluid stored within the syringe; and
a switch for releasing a pressurized gas from the source into the syringe so as to cause the device to deliver a jet of conductive fluid at a speed sufficient to penetrate tissue to a depth within the range of about 2 mm to about 5 mm.
22 . A method of forming a lesion within tissue comprising the steps of:
providing access to the heart of a patient;
injecting a portion of the tissue with a jet of conductive fluid to a depth within the range of about 2 mm to about 5 mm; and
ablating at least some of the tissue injected with the jet of conductive solution using RF ablation.
23 . A RF ablation probe comprising:
a handle;
a shaft attached to the handle;
a distal section having a lumen therethrough, the distal section including a plurality of ports oriented on one side of the distal section, the distal section further including a plurality of RF electrodes; and
a source of pressurized conductive-fluid connected to the lumen of the probe.
24 . The RF ablation probe of claim 23 , wherein the distal section comprises hypotube having an internal diameter within the range of about 0.010″ to about 0.025″.
25 . The RF ablation probe of claim 23 , wherein the plurality of ports have diameters within the range of about 0.002″ to about 0.004″.
26 . The RF ablation probe of claim 23 , wherein the source of pressurized conductive fluid is pressurized so as to produce an injection pressure within the range of about 500 psi to about 1500 psi.
27 . A RF ablation catheter comprising:
a handle;
a shaft attached to the handle;
a distal segment having a lumen therethrough, the distal segment including a plurality of ports oriented on one side of the distal segment, the distal segment further including a plurality of RF electrodes; and
a source of pressurized conductive fluid connected to the lumen of the catheter.