Electrosurgical electrodes

Abstract

An electrode assembly is provided. The electrode assembly includes a proximal end that is adapted to connect to an electrosurgical instrument including a housing defining a longitudinal axis therethrough and an electrosurgical energy source. A distal end includes a cutting electrode having a loop configuration configured to cut tissue. The distal end includes a return electrode operably disposed adjacent the cutting electrode. A dielectric shield is operably disposed between the cutting electrode and return electrode. The dielectric shield extending distally past the cutting electrode to hinder current flow to the return electrode when the dielectric shield, cutting electrode and return electrode are submersed in a conductive solution and the cutting electrode is energized, thereby concentrating current density at the cutting electrode.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present application claims the benefit of and priority to U.S. Provisional Application Ser. No. 61 / 766,483 filed by Ward on Feb. 19, 2013, the entire contents of which hereby incorporated by reference.BACKGROUND[0002]1. Technical Field[0003]The present disclosure relates to electrosurgical electrodes and, more particularly, to electrosurgical electrodes that provide concentrated amounts of electrosurgical energy to tissue during an electrosurgical procedure.[0004]2. Background of Related Art[0005]Currently, there are several surgical therapies utilized for treating benign prostate hyperplasia (BPH). At present, transurethral resection of the prostate (TURP) is predominant in the surgical therapy of BPH. Various alternative treatment devices, e.g., electrovaporization, needle ablation, laser, ultrasound, or microwave therapy have recently become available for treating BPH. However, for efficacy, TURP is still regarded as the reference ...

AI Technical Summary

Benefits of technology

[0018]Yet another aspect of the present disclosure provides an electrosurgical instrument. The electrosurgical instrument includes an elongated sheath including a sheath lumen, a distal end and a proximal end. An electrode assembly includes a proximal end adapted to connect to an electrosurgical instrument including a housing defining a longitudinal axis therethrough and an electrosurgical energy source. A distal end includes a cutting electrode having a loop configuration configured to cut tissue. The loop configuration of the cutting electrode has a non-uniform cross-section diameter. The distal end includes a return electrode that is operably disposed adjacent the cutting electrode. The non-uniform cross-section diameter of the cutting electrode hinders current flow to the return electrode when the cutting electrode and return electrode are submersed in a conductive solution and the cutting electrode is energized, thereby concentrating current density at the cutting electrode.

[0019]Another aspect of the present disclosure provides an electrode assembly adapted to connect to an electrosurgical instrument. A proximal end of the electrode assembly is adapted to connect to an electrosurgical instrument including a housing defining a longitudinal axis therethrough and an electrosurgical energy source. A distal end of the electrode assembly includes a cutting electrode having a loop configuration configured to cut tissue. The loop configuration of the cutting electrode having a surface finish minimizing the energy required for bubble nucleation on the cutting electrode and promoting vapor bubble adhesion. The surface finish may include a pitted finish or a hydrophobic finish. The distal end including a return electrode that is operably disposed adjacent the cutting electrode. The surface finish of the cutting electrode hinders current flow to the return electrode when the cutting electrode and return electrode are submersed in a conductive solution and the cutting electrode is energized, thereby concentrating current density at the cutting electrode.

[0020]Another aspect of the present disclosure provides an electrode assembly adapted to connect to an electrosurgical instrument. A proximal end of the electrode assembly is adapted to connect to an electrosurgical instrument including a housing defining a longitudinal axis therethrough and an electrosurgical energy source. A distal end of the electrode assembly including a cutting electrode having a loop configuration configured to cut tissue. The distal end including a return electrode that is operably disposed adjacent the cutting electrode at a distance maximizing energy per volume and minimizing heating depth such that hemostasis is maximized at a target tissue site. The distance may be in the range from about 3 mm to about 10 mm. The distal end including a return electrode operably disposed adjacent the cutting electrode. The distance between the return electrode and the cutting electrode hinders current flow to the return electrode when the cutting electrode and return electrode are submersed in a conductive solution and the cutting electrode is energized, thereby concentrating current density at the cutting electrode.

[0021]The cutting electrode and return electrode may be in fixed spaced-apart relation with respect to one another. The cutting electrode and return electrode may be in a selectably movable spaced-apart relation with respect to one another such that a variable tissue effect is achieved at the target tissue site. The return electrode may include two return electrodes operably disposed on a respective longitudinal section associated with the electrode assembly. The two return electrodes maybe slidably and axially movable with respect to each other and the cutting electrode.

Problems solved by technology

Disadvantages associated with monopolar electrocautery systems when employed in the treatment of BPH include collateral damage to adjacent tissue (e.g., heating of tissue that is deeper than tissue being treated), unwanted stimulation of the nervous and / or muscle system, and / or possible malfunction of therapeutic devices in operative contact with a patient (e.g., a pacemaker).

Another disadvantage associated with monopolar electrocautery systems when employed in the treatment of BPH may include the absorption of hypoosmolar irrigation fluid by a patient (commonly referred to in the art as TUR or TURP syndrome), which is typically a result of extended TURP procedures.

While bipolar electrocautery systems utilized for treating BPH alleviate some, if not all, of the disadvantages associated with monopolar electrocautery systems for treating BPH, there still exists some practical challenges with bipolar electrocautery systems to treat BPH.

Bleeding causes a decrease in visual clarity which, in turn, may lead to a variety of intraoperative difficulties with undesirable consequences, e.g., increased convalescence.

However, when the active electrode is positioned in a conductive medium (e.g., a conductive fluid such as saline) a significant fraction of the applied current passes through the saline to the return electrode(s) and not to the target tissue resection site.

This fraction of applied current passing through the saline to the return electrode(s) results in decreased hemostatic efficacy at the target tissue resection site.

Moreover, this fraction of the current passing through the saline to the return electrode(s) results in TURP procedures having high power output requirements (due to the reduction of a tissue current density, which, in turn, results in overall applied power being increased to the active electrode).

The non-uniform cross-section diameter of the cutting electrode hinders current flow to the return electrode when the cutting electrode and return electrode are submersed in a conductive solution and the cutting electrode is energized, thereby concentrating current density at the cutting electrode.

The non-uniform cross-section diameter of the cutting electrode hinders current flow to the return electrode when the cutting electrode and return electrode are submersed in a conductive solution and the cutting electrode is energized, thereby concentrating current density at the cutting electrode.

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