Methods For Radio Frequency Neurotomy

What is this patent about?

’664 is related to the field of thermal ablation systems, specifically radio frequency (RF) neurotomy. This technique aims to disrupt a nerve's ability to transmit pain signals to the brain by cauterizing the target nerve with RF energy. Existing methods often struggle with limited access to the target nerve and anatomical variations, making it challenging to create lesions of sufficient size and optimal clinical outcomes while sparing surrounding tissue.

The underlying idea behind ’664 is to enhance RF neurotomy by using a specialized needle with deployable filaments that extend from the tip. These filaments increase the effective surface area for RF energy delivery, creating a larger and more customizable lesion volume. By manipulating the position and orientation of these filaments, the physician can precisely target the desired nerve tissue while minimizing damage to surrounding structures.

The claims of ’664 focus on a method involving inserting a needle with an elongate member, a piercing tip, a lumen, and a retractable filament. The method includes moving the filament to a deployed position where its distal end extends beyond the elongate member and away from the tip. A radiofrequency probe is then inserted into the needle's lumen, establishing electrical contact with a conductive portion of the needle at its distal end. Finally, the radiofrequency probe, the tip, and the filament are operated as a monopolar electrode , with RF energy from the probe conducted to the filament and transmitted into the surrounding tissue.

In practice, the physician navigates the needle to a position near the target nerve using imaging guidance. Once in place, the filaments are deployed, expanding the area of RF energy delivery. The RF probe, inserted through the needle's lumen, then delivers energy to the tip and filaments, creating a lesion that ablates the target nerve. The ability to adjust the filament deployment allows for tailoring the lesion's size and shape to the specific anatomical context.

’664 differentiates itself from prior approaches by overcoming the limitations of conventional single-electrode RF probes. The multiple filaments provide additional conduits for RF energy, creating a multipolar RF field effect. This allows for larger and more customizable lesions, addressing the challenges of limited access and anatomical variations. The invention also enables the creation of lesions offset from the needle's axis, facilitating precise targeting of nerves near sensitive structures.