Patient selection using a transluminally-applied electric current
Apparatus for facilitating ablation of nerve tissue of a subject is provided, comprising (1) an ablation unit, configured to be percutaneously advanced to a site adjacent to a first portion of the nerve tissue; (2) at least one electrode unit, coupled to the ablation unit, and configured to be percutaneously advanced to a site adjacent to a second portion of the nerve tissue, and to initiate unidirectional action potentials in the nerve tissue, such that the unidirectional action potentials propagate toward the first portion of the nerve tissue; and (3) a control unit, configured: (a) to drive the ablation unit to ablate, at least in part, the first portion of the nerve tissue of the subject, and (b) to drive the at least one electrode unit to initiate the unidirectional action potentials by applying an excitatory current to the second portion of the nerve tissue.
1. A method, comprising:
transluminally advancing a distal portion of a longitudinal member of a device into a renal artery of a subject;
operating the device to drive an electrode disposed on the distal portion of the longitudinal member to apply a non-ablative electrical current to nerve tissue of the renal artery;
receiving (i) a first value, the first value being indicative of a blood pressure of the subject before a start of the application of the current, and (ii) a second value, the second value being indicative of the blood pressure of the subject after a start of the application of the current;
determining if a difference between the first value and the second value is smaller than a threshold difference; and
in response to the determining, selecting the subject for performance or non-performance of ablation of a renal artery of the subject, wherein selecting comprises:
if the determined difference is greater than the threshold difference, operating the device to apply ablation energy to the renal artery; whereas
if the determined difference is smaller than the threshold difference, withdrawing the longitudinal member from the subject without having applied ablation energy to the renal artery.
2. The method according to claim 1 , wherein the non-ablative electrical current is a non-ablative blocking current, and wherein driving the electrode to apply the non-ablative electrical current to the nerve tissue comprises driving the electrode to apply the non-ablative blocking current to the nerve tissue.
3. The method according to claim 1 , wherein the non-ablative electrical current is an excitatory current, and wherein driving the electrode to apply the non-ablative electrical current to the nerve tissue comprises driving the electrode to apply the excitatory current to the nerve tissue.
4. The method according to claim 3 , wherein driving the electrode to apply the excitatory current to the nerve tissue comprises inducing unidirectional action potentials in the nerve tissue.
5. The method according to claim 1 , wherein transluminally advancing the longitudinal member into the renal artery of the subject comprises transfemorally advancing the longitudinal member into the renal artery of the subject.
6. The method according to claim 1 , wherein the electrode is a first electrode, and operating the device to drive the electrode to apply the non-ablative current comprises operating the device to drive the non-ablative current between the first electrode and a second electrode disposed on the distal portion of the longitudinal member.
7. The method according to claim 1 , wherein the steps of receiving and determining comprise operating the device to (i) receive the first value and the second value, and (ii) determine if the difference is smaller than the threshold difference.