Catheter apparatuses having expandable baskets for renal neuromodulation and associated systems and methods
Methods and apparatus are provided for treating hypertension, e.g., via a pulsed electric field, via a stimulation electric field, via localized drug delivery, via high frequency ultrasound, via thermal techniques, etc. Such neuromodulation may effectuate irreversible electroporation or electrofusion, necrosis and/or inducement of apoptosis, alteration of gene expression, action potential attenuation or blockade, changes in cytokine up-regulation and other conditions in target neural fibers. In some embodiments, neuromodulation is applied to neural fibers that contribute to renal function. In some embodiments, such neuromodulation is performed in a bilateral fashion. Bilateral renal neuromodulation may provide enhanced therapeutic effect in some patients as compared to renal neuromodulation performed unilaterally, i.e., as compared to renal neuromodulation performed on neural tissue innervating a single kidney.
1. A method for catheter-based renal denervation of a human patient, the method comprising:
intravascularly positioning a first catheter having a first expandable basket in a low-profile delivery configuration within a first renal artery of the patient and proximate to renal nerves innervating a first kidney of the patient,
wherein the first expandable basket is sized and shaped for the first renal artery, and wherein the first expandable basket comprises a plurality of first electrodes arranged thereon,
transforming the first expandable basket from the delivery configuration to a treatment configuration such that the first electrodes on the first expandable basket are in contact with an inner wall of the first renal artery;
attenuating neural communication along the renal nerves innervating the first kidney via radio frequency (RF) energy from the first electrodes;
intravascularly positioning a second catheter having a second expandable basket in a low-profile delivery configuration within a second renal artery of the patient and proximate to renal nerves innervating a second kidney of the patient,
wherein the second expandable basket is sized and shaped for the second renal artery, and wherein the second expandable basket comprises a plurality of second electrodes arranged thereon;
transforming the second expandable basket from the delivery configuration to a treatment configuration such that the plurality of second electrodes on the second expandable basket are in contact with an inner wall of the second renal artery; and
attenuating neural communication along the renal nerves innervating the second kidney via RF energy from the second electrodes,
wherein attenuating neural communication along the renal nerves innervating the first kidney and the renal nerves innervating the second kidney results in a therapeutically beneficial reduction in blood pressure in the patient.
2. The method of claim 1 wherein:
positioning the first catheter within the first renal artery of the patient comprises intravascularly delivering the first catheter to the first renal artery over a first guidewire; and
positioning the second catheter within the second renal artery of the patient comprises intravascularly delivering the second catheter to the second renal artery over a second guidewire.
3. The method of claim 1 wherein:
attenuating neural communication along the renal nerves innervating the first kidney comprises ablating the renal nerves innervating the first kidney via RF energy from the first electrodes; and
attenuating neural communication along the renal nerves innervating the second kidney comprises ablating the renal nerves innervating the second kidney via RF energy from the second electrodes.
4. The method of claim 1 wherein:
attenuating neural communication along the renal nerves innervating the first kidney comprises partially ablating the renal nerves innervating the first kidney via RF energy from the first electrodes; and
attenuating neural communication along the renal nerves innervating the second kidney comprises partially ablating the renal nerves innervating the second kidney via RF energy from the second electrodes.
5. The method of claim 1 wherein:
attenuating neural communication along the renal nerves innervating the first kidney comprises denervating the first kidney of the patient; and
attenuating neural communication along the renal nerves innervating the second kidney comprises denervating the second kidney of the patient.
6. The method of claim 1 wherein the first renal artery has a different diameter than the second renal artery, and wherein the first basket comprises a different size than the second basket.
7. The method of claim 1 wherein the first renal artery has the same or approximately the same diameter as the second renal artery, and wherein the first basket is the same size as the second basket.
8. The method of claim 1 , further comprising removing the first catheter from the first renal artery of the patient before positioning the second catheter within the second renal artery of the patient.
9. The method of claim 1 wherein positioning the first catheter within the first renal artery of the patient and positioning the second catheter within the second renal artery of the patient occur simultaneously.
10. The method of claim 1 wherein:
in the treatment configuration, the first basket does not occlude blood flow in the first renal artery,
in the treatment configuration, the second basket does not occlude blood flow in the second renal artery.
11. The method of claim 1 wherein attenuating neural communication along the renal nerves innervating the first kidney and the renal nerves innervating the second kidney further results in a therapeutically beneficial reduction in central sympathetic overactivity of the patient.
12. The method of claim 1 , further comprising removing the first catheter and the second catheter from the patient to conclude the procedure.
13. The method of claim 1 , further comprising monitoring a parameter of target tissue and/or non-target tissue within the patient before and during RF energy delivery.
14. The method of claim 13 wherein monitoring a parameter comprises monitoring temperature of target tissue, and wherein the method further comprises maintaining the target tissue at a desired temperature during energy delivery.
15. The method of claim 13 , further comprising altering RF energy delivery in response to the monitored parameter.
16. The method of claim 13 , further comprising adjusting a treatment parameter in response to the monitoring.
17. A method for treatment of a hypertensive human patient, the method comprising:
positioning a catheter having an expandable distal basket within a first renal artery of the patient;
at least partially ablating nerves along the first renal artery via electrical energy from electrodes carried by the expandable distal basket;
positioning the catheter having the expandable distal basket within a second renal artery of the patient; and
at least partially ablating nerves along the second renal artery via electrical energy from the electrodes carried by the expandable distal basket,
wherein at least partially ablating the nerves along the first renal artery and the nerves along the second renal artery results in a therapeutically beneficial reduction in blood pressure in the hypertensive patient.
18. The method of claim 17 wherein positioning the catheter within the first renal artery and at least partially ablating nerves along the first renal artery occurs at a first treatment site within the first renal artery, and wherein the method further comprises positioning the catheter at one or more additional treatment sites within the first renal artery and at least partially ablating nerves along the first renal artery via electrical energy from electrodes carried by the expandable distal basket before positioning the catheter within the second renal artery.
19. The method of claim 17 , further comprising:
monitoring a parameter of target tissue and/or non-target tissue within the patient before and during delivery of electrical energy from the electrodes; and
altering electrical energy delivery via the electrodes in response to the monitored parameter.