Methods and devices for endovascular ablation of a splanchnic nerve
Systems, devices, and methods for transvascular ablation of target tissue. The devices and methods may, in some examples, be used for splanchnic nerve ablation to increase splanchnic venous blood capacitance to treat at least one of heart failure and hypertension. For example, the devices disclosed herein may be advanced endovascularly to a target vessel in the region of a thoracic splanchnic nerve (TSN), such as a greater splanchnic nerve (GSN) or a TSN nerve root. Also disclosed are methods of treating heart failure, such as HFpEF, by endovascularly ablating a thoracic splanchnic nerve to increase venous capacitance and reduce pulmonary blood pressure.
1. A method of positioning an energy delivery device, comprising:
imaging at least one radiopaque device that comprises a radiopaque marker carried by the energy delivery device, positioned in at least one of a patient's azygos vein or an intercostal vein, relative to a portion of a spine, using a radiographic imaging device, to thereby characterize a position of the patient's azygos vein relative to a midline of the spine;
determining whether the azygos vein is centered, left-biased or right biased with respect to the midline of a vertebra based on one or more images generated by said radiographic imaging device; and
subsequent to determining whether the azygos vein is centered, left-biased or right biased with respect to the midline of the vertebra, in the patient whose azygos vein is determined to be left-biased with respect to the midline of the vertebra and not centered or right biased with respect to the midline of the vertebra, positioning a distal end of the energy delivery device in the intercostal vein and positioning the radiopaque marker at the midline of the vertebra.
2. The method of claim 1 , wherein positioning the radiopaque marker at the midline of the vertebra comprises distally advancing the radiopaque marker within an intercostal vein distal to an ostium of the intercostal vein.
3. The method of claim 1 , further comprising assessing a position of a distal radiopaque marker carried by the energy delivery device relative to one or more of a costovertebral joint or rib, the method further comprising retracting the energy delivery device within the intercostal vein if the distal radiopaque marker is positioned distally beyond a certain position relative to the rib or the costovertebral joint.
4. The method of claim 1 , further comprising positioning a distal radiopaque marker carried by the energy delivery device to be aligned with or proximal to a costovertebral joint.
5. The method of claim 1 , wherein the imaging comprises imaging with an anterior oblique view.
6. The method of claim 1 , wherein the imaging comprises imaging in an anterior-to-posterior direction.
7. The method of claim 1 , wherein the radiopaque device comprises a radiopaque portion of a guidewire.
8. The method of claim 1 , wherein imaging comprises positioning a C-arm in a Right Anterior Oblique angle.
9. The method of claim 8 , wherein the positioning a C-arm step comprises positioning the C-arm in a range of 20 degrees to 70 degrees.
10. The method of claim 1 , wherein the positioning step comprises positioning an ablation element carried by the energy delivery device at least partially into a T9, T10, or T11 intercostal vein, and delivering ablative energy using the ablation element to ablate a greater splanchnic nerve (“GSN”).
11. The method of claim 10 , wherein the ablation element has a length from 15 mm to 30 mm.
12. The method of claim 10 , further comprising moving the ablation element to a different one of the T9, T10, or T11 intercostal veins, and delivering energy from the ablation element when in the different vein after the moving step.
13. The method of claim 1 , wherein the energy delivery device further comprises an ablation element distal to the radiopaque marker, wherein positioning the radiopaque marker at the midline of the vertebra comprises positioning the ablation element in the intercostal vein.
14. The method of claim 13 , wherein positioning the radiopaque marker comprises positioning the ablation element in a T9, T10, or T11 intercostal vein.
15. The method of claim 13 , wherein positioning the radiopaque marker positions the ablation element proximal to a sympathetic trunk.
16. The method of claim 13 , wherein positioning the radiopaque marker positions the ablation element between an ostium of the intercostal vein and a sympathetic trunk.
17. The method of claim 13 , further comprising delivering ablation energy using the ablation element to ablate a greater splanchnic nerve (“GSN”).
18. A method of positioning an energy delivery device, comprising:
imaging at least one radiopaque device, positioned in at least one of an azygos vein or an intercostal vein, relative to a portion of a spine, using a radiographic imaging device, to thereby characterize a position of the patient's azygos vein relative to a midline of the spine;
determining whether the azygos vein is centered, left-biased or right biased with respect to the midline of the vertebra based on one or more images generated by said radiographic imaging device; and
subsequent to determining whether the azygos vein is centered, left-biased or right biased with respect to the midline of the vertebra, in a patient whose azygous vein is determined to be right-biased with respect to the midline of the vertebra and not centered or left-biased with respect to the midline of the vertebra, positioning a radiopaque marker of the energy delivery device to be aligned with or proximal to a rib or a costovertebral joint, the energy delivery device further comprising an ablation element proximal to the radiopaque marker.
19. The method of claim 18 , further comprising using the ablation element to ablate a greater splanchnic nerve (“GSN”).