Carotid body ablation with a transvenous ultrasound imaging and ablation catheter
Methods and devices for assessing, and treating patients having sympathetically mediated disease, involving augmented peripheral chemoreflex and heightened sympathetic tone by reducing chemosensor input to the nervous system via carotid body ablation.
1. An ultrasound ablation catheter, comprising:
a distal assembly comprising an ultrasound ablation transducer, an echolucent shell, and an ablation direction fiducial marker, the echolucent shell at least partially defining a distal chamber, the ultrasound ablation transducer disposed within the distal chamber, the distal assembly adapted to house therein an ultrasound imaging transducer,
the ablation direction fiducial marker positioned relative to the ultrasound ablation transducer and adapted to, when an ultrasound imaging transducer is positioned and activated within the distal assembly, create an aiming artifact on an image created by the ultrasound imaging transducer, the aiming artifact adapted to be used to indicate a direction of ablation; and
an elongate shaft extending proximally from the distal assembly.
2. The catheter of claim 1 wherein the ablation direction fiducial marker is axially aligned with the ultrasound imaging catheter when the ultrasound image transducer is in an active position in the distal assembly.
3. The catheter of claim 1 wherein the ablation direction fiducial marker is disposed relative to the ultrasound ablation transducer such that the direction of the ablation energy emitted from the ultrasound ablation transducer can be determined based on the location of the indicator on the image.
4. The catheter of claim 3 wherein the ablation direction fiducial marker is secured to the echolucent shell.
5. The catheter of claim 4 wherein the echolucent shell comprises first and second membranes, the ablation direction fiducial marker secured between the first and second membranes.
6. The catheter of claim 5 wherein the ablation direction fiducial marker has a curved configuration.
7. The catheter of claim 1 wherein the ablation direction fiducial marker has a curved configuration.
8. The catheter of claim 1 wherein the ablation direction fiducial marker has a configuration that is a partial tubular member.
9. The catheter of claim 1 wherein the ablation direction fiducial marker is an extension of a support member disposed proximal to the ablation direction fiducial marker.
10. The catheter of claim 1 wherein the ablation direction fiducial marker is an echo-opaque material.
11. The catheter of claim 10 wherein the ablation direction fiducial marker comprises stainless steel.
12. The catheter of claim 1 wherein the ultrasound ablation catheter is configured to be inserted through a jugular vein of a patient and wherein the ultrasound ablation transducer is configured to be placed in proximity to a target ablation site including a carotid body.
13. The catheter of claim 1 wherein the distal assembly further comprises a lumen therein configured to receive therethrough an ultrasound imaging catheter.
14. The catheter of claim 1 wherein the ultrasound ablation transducer is a flat transducer with an axial axis that is parallel to the longitudinal axis of the elongate shaft in a straight configuration.
15. The catheter of claim 14 wherein the flat transducer is disposed in an outer radial portion of the distal region.
16. The catheter of claim 1 wherein the echolucent shell has a first thickness at a first axial location of the ablation ultrasound transducer, and a second thickness greater than the first thickness at a second axial location distal to the ablation ultrasound transducer.
17. The catheter of claim 16 wherein the echolucent shell comprises at least first and second membrane sections that are affixed together in the second axial location.
18. The catheter of claim 1 further comprising a fluid lumen, the fluid lumen in fluid communication with the ultrasound ablation transducer, the fluid lumen also comprising an electrical connector in electrical communication with the ablation ultrasound transducer.
19. The catheter of claim 1 further comprising a manifold secured to and extending distally from at least a portion of the elongate shaft, the ablation ultrasound transducer mounted to the manifold.
20. The catheter of claim 19 further comprising a wafer secured between the ablation ultrasound transducer and the manifold.
21. The catheter of claim 19 wherein the manifold further comprises a lumen adapted to receive an ultrasound imaging catheter therein.
22. The catheter of claim 19 wherein the manifold comprises at least one fluid exit lumen in communication with a proximal region of the catheter.
23. The catheter of claim 19 wherein the manifold comprises a recess defined by side edges and a back plate, the recess adapted to receive therein the ultrasound ablation transducer, wherein the ablation transducer is secured within the recess such that the side edges extend radially outward relative to the ablation transducer to allow the free flow of cooling fluid over the ablation transducer.
24. The catheter of claim 23 wherein the manifold is configured to induce turbulent flow of cooling fluid over the ablation transducer.