Multi-modality ablation catheter having a shape memory stylet
A multimodality or hybrid ablation system includes an ablation apparatus for creating a lesion in target tissue. The ablation apparatus has an ablation shaft including a handle, a first portion, an ablation portion, distal tip, at least one ablation energy delivery lumen, at least one ablation energy return lumen, and a stylet lumen that extends substantially along a length of the ablation shaft from the handle to at least the ablation portion. The ablation apparatus also includes a stylet that is capable of being inserted into the stylet lumen where the stylet is made of a shape-memory material. A plurality of electrodes are arranged on the ablation portion for measuring or verifying tissue contact with the tissue and applying a pulsed electric field. Optionally, the pulsed electric field may be applied after or in parallel with freezing the target tissue.
1 . A multimodality ablation system for creating a lesion in target tissue, the system comprising:
a catheter, said catheter comprising:
a freezing portion;
at least one cryogen delivery lumen;
at least one cryogen return lumen; and
a plurality of therapeutic electrodes configured to deliver pulsed field ablation energy and measure tissue contact information, said therapeutic electrodes disposed directly on an exterior surface of the freezing portion; and
a generator framework operable with the plurality of electrodes to (a) measure tissue contact information, and (b) create pulsed field of electricity to induce cell death during cryogenic conditions.
2 . The system of claim 1 , wherein the catheter further comprises a stylet lumen that extends substantially along a length of the ablation shaft from the handle to at least the freezing portion; and a stylet capable of being inserted into the stylet lumen, the stylet comprising a pre-set shape.
3 . The system of claim 2 , further comprising a cryogen controller operable to circulate a cryogen through the freezing section using the at least one cryogen delivery lumen and the cryogen return lumen.
4 . The system of claim 1 , wherein the generator framework comprises a pulsed field ablation generator operable to create the pulsed field of electricity to induce cell death, and optionally, to measure tissue contact information.
5 . The system of claim 4 , wherein the catheter further comprises a positive charge EP connector for supplying a positive voltage to a first set of the plurality of electrodes and compatible with an EP recording system, and the catheter further comprises a negative charge EP connector for supplying a negative voltage to a second set of the plurality of electrodes and compatible with an EP recording system.
6 . The system of claim 5 , further comprising a PFA adapter cable to electrically couple the positive charge EP connector and the negative charge EP connector to the PFA controller.
7 . A method for treating heart disease by creating at least one lesion in a patient using a multi-modality ablation apparatus, the method comprising:
advancing a distal treatment section of the multi-modality ablation apparatus into the heart, and wherein the multi-modality ablation apparatus comprises a plurality of therapeutic electrodes arranged directly on an exterior surface of the distal treatment section;
manipulating the distal treatment section of the multi-modality ablation apparatus into contact with a first target tissue in which the at least one lesion shall be created;
evaluating tissue contact for a length of continuous contact between the distal treatment section and the first target tissue based on contact information arising from the plurality of electrodes;
optionally adjusting the position of the distal treatment section to increase the length of continuous contact;
selecting at least one ablation modality from the group consisting of cryogenic ablation and pulsed field ablation;
switching the electrodes between tissue contact and ablation modalities via generator switching while maintaining catheter position and tissue contact; and
ablating the first target tissue with the selected at least one ablation modality to create a first lesion, wherein the distal treatment section is operable to perform both cryoablation and pulsed field ablation without requiring catheter exchange or modification; wherein the plurality of electrodes are configured to deliver pulsed field ablation energy and measure tissue contact information, and operable during cryogenic conditions.
8 . The method of claim 7 , wherein the selected at least one ablation modality is pulsed field ablation and cryoablation.
9 . The method of claim 8 , wherein the ablation modalities are performed in sequence on said first target tissue.
10 . The method of claim 7 , wherein the selected at least one ablation modality is based on a tissue type.
11 . A method for creating at least one lesion in a patient using a multi-modality ablation apparatus, the method comprising:
selecting at least one ablation modality from the group consisting of cryo- and pulsed field ablation; and
ablating a first target tissue with the selected at least one ablation modality to create a first lesion;
wherein the selected at least one ablation modality is based on a tissue type; and wherein pulsed field ablation (PFA) is selected for treating myocardium tissue, cryoablation is selected for treating non-myocardium tissue, and a hybrid ablation using both PFA and cryoablation is selected for treating a target area comprising myocardial and non-myocardial tissue.
12 . The method of claim 7 , further comprising selecting at least one ablation modality from the group consisting of cryoablation and pulsed field ablation to ablate a second target tissue subsequent to ablating the first target tissue, and ablating the second target tissue.
13 . The method of claim 12 , wherein the ablation modality selected for the second target tissue is not identical to the ablation modality selected for the first target tissue.
14 . The method of claim 13 , wherein the ablation modality selected for the second target tissue is a hybrid ablation including both cryoablation and pulsed field ablation.
15 . The method of claim 8 , wherein the cryoablation comprises creating an ice layer surrounding the treatment portion of the catheter, and the pulsed field ablation is performed subsequent to the cryoablation and comprises applying a voltage through the ice layer to create an electric field in the tissue beyond the ice layer.
16 . The method of claim 15 , wherein the ice layer has a thickness less than or equal to 500 um.
17 . The method of claim 16 , wherein the electric field extends at least 4 mm from a surface of the catheter into the tissue.
18 . The method of claim 15 , wherein the ice layer has a thickness equal to or greater than 3 mm.
19 . The method of claim 18 , wherein the applied electric field is confined to the ice layer.
20 . The system of claim 3 , wherein the pulsed field ablation generator is operable to create an electric field subsequent to forming a layer of ice around the freezing portion of the catheter.
21 . The system of claim 20 , wherein catheter is operable to generate an ice layer having a thickness less than or equal to 500 um.
22 . The system of claim 20 , wherein the pulsed field ablation generator is operable to create an electric field that extends a depth of at least 4 mm from a surface of the freezing portion of the catheter into the tissue.
23 . The system of claim 20 , wherein the pulsed field ablation generator is operable to create the electric field subsequent to forming the layer of ice such that a ratio of the depth of the electric field to ice thickness is at least 100.
24 . The system of claim 20 , wherein the cryoablation controller is operable to limit the duration of cryoablation to less than or equal to 10 s.
25 . The system of claim 1 , wherein the catheter further comprises an irrigation aperture in the distal section for delivering a liquid in the vicinity of the electrodes.
26 . The system of claim 1 , further comprising a modality detection module operable to recognize whether the catheter plugged the PFA generator is configured for PFA-only or PFCA therapy.
27 . The method of claim 7 , further comprising:
automatically determining which electrodes to pulse during pulsed field ablation based on which electrodes have an acceptable measured tissue contact value.