System and method for denervation
Inventors
ABUNASSAR, CHAD • Stankus, John • Magana, Jesus • Mackiewicz, David • Trollsas, Mikael • Hossainy, Syed • Perrin, Scott
Assignees
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Publication Number
US-9333113-B2
Publication Date
2016-05-10
Expiration Date
Abstract
A catheter apparatus for treatment of a human patient is described, the catheter apparatus having a central axis and comprising a shaping structure moveable between a delivery state having a first helical shape, and a deployed state having a second helical shape. The shaping structure is configured to have a reverse taper with a structural diameter that varies over the length of the shaping structure such that the structural diameter of the shaping structure at the proximal end is smaller than the structural diameter of the shaping structure at the distal end.
Core Innovation
The invention relates to a catheter apparatus for treatment of a human patient. The catheter apparatus includes a shaping structure movable between a delivery state having a first helical shape and a deployed state having a second helical shape, and the shaping structure carries a plurality of electrodes positioned from the proximal end through at least one intermediate location to the distal end.
A plurality of electric wires connect the electrodes to a proximally positioned electric energy supply source. The deployment member is operably coupled to the distal end of the shaping structure and disposed parallel to the central axis, where distal axial movement places the shaping structure in the delivery state and proximal axial movement places the shaping structure in the deployed state.
The shaping structure is formed from an elongate element configured such that the elongate element has a reverse taper with a gauge diameter that varies over its length, with the gauge diameter at the proximal end smaller than the gauge diameter at the distal end. The gauge diameter at the location of each successive electrode moving in the distal direction is larger than the gauge diameter at the location of the adjacent proximally spaced electrode, to equalize electrode-to-vessel wall contact force across the electrodes.
The disclosed application context is RF-based renal neuromodulation/denervation using an intravascular multi-electrode catheter in a renal artery, and the patent further describes a circumferentially discontinuous helical lesion pattern intended to reduce stenosis risk. It also includes finite-element analysis and animal test observations indicating more uniform vascular lesion magnitude with the reverse taper, and a second force-equalization approach using radially offset electrode geometry.
Claims Coverage
The independent claim coverage is centered on a single catheter apparatus with a helical shaping structure that transitions between a delivery state and a deployed state, a plurality of electrodes connected to a proximally positioned electric energy supply source, and a reverse taper that increases gauge diameter toward the distal end at successive electrode locations. Dependent refinements specify enlargement profile constraints and a deployment-member tubular member for a guide wire.
Reverse-tapered helical shaping structure transitioning between delivery and deployed states
The shaping structure is moveable between a delivery state having a first helical shape and a deployed state having a second helical shape, and is formed from an elongate element having a reverse taper with a gauge diameter that varies over the length such that the gauge diameter at the proximal end is smaller than the gauge diameter at the distal end.
Successive electrode locations with increasing gauge diameter in the distal direction
The gauge diameter of the elongate element at the location of each successive electrode, moving in the distal direction, is larger than the gauge diameter of the elongate element at the location of the adjacent proximally spaced electrode.
Multi-electrode array positioned along the shaping structure and wired to a proximally positioned energy supply source
A plurality of electrodes are carried by the shaping structure, with one electrode at the proximal end, one electrode at the distal end, and at least one electrode between the proximal end and the distal end, the electrodes being spaced apart from one another, wherein each electrode is connected to at least one electric wire extending via the proximal end to a proximally positioned electric energy supply source.
Deployment member driving delivery-state to deployed-state helical transformation
A deployment member operably coupled to the distal end of the shaping structure and disposed parallel to the central axis, configured such that distal axial movement of the deployment member places the shaping structure in the delivery state and proximal axial movement of the deployment member places the shaping structure in the deployed state.
Across the provided independent claim and its main refinements, the coverage is centered on the helical catheter apparatus with spaced electrodes connected to a proximal energy supply, and the reverse taper that increases gauge diameter from proximal to distal at successive electrode locations to address electrode-contact-force non-uniformity. Dependent refinements specify monotonic or stepwise enlargement profiles and quantitative limits on gauge-diameter enlargement rate and overall gauge-diameter increase.
Stated Advantages
Equalize electrode-to-vessel wall contact force across electrodes.
Avoid over-heating/burning by the middle electrode seen with a uniform-diameter helical structure.
Reduce stenosis risk using a circumferentially discontinuous helical lesion pattern.
More uniform vascular lesion magnitude, as indicated by finite-element analysis and animal test observations.
Documented Applications
RF-based renal neuromodulation/denervation in a renal artery using an intravascular multi-electrode catheter.
Treatment intended to form circumferentially discontinuous helical lesions to reduce stenosis risk.
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