A conductive coating may be adhered to a structure comprising a hydrophobic and/or adhesion-resistant surface. The conductive coating may have a polymer backbone with conductive particles suspended in the backbone. In some embodiments, the conductive coating may be applied directly to the surface. In other embodiments, the conductive coating may be indirectly applied by first applying a primer adhesive to the outer surface, and then applying the conductive coating over the primer adhesive. An example structure may be a catheter of an endoscopic medical device, such as a bipolar sphincterotome, where the conductive coating functions as a return electrode.

An electrosurgical device includes an elongated shaft, an active electrode, and a return electrode. The elongated shaft has an end effector that is operably engaged with a distal portion thereof and a channel defined therethrough. The distal portion of the elongated shaft includes a distal tip that is configured to provide suction from a suction surface to the distal tip through the channel. The end effector may include a flare a proximal end thereof. The active electrode is positioned adjacent the distal tip of the elongated shaft and is configured to deliver electrosurgical energy to tissue. The return electrode is positioned on an outer surface of the end effector proximal of the active electrode. The return electrode is configured to provide a return path for the electrosurgical energy.

A tissue resecting device includes an outer sleeve having an axial bore extending along a longitudinal axis from a proximal end to a distal end and opening to an outer window near the distal end. An inner sleeve is rotatably received in the axial bore of the outer sleeve and has an axial channel adapted for communication with a negative pressure source. A distal housing is attached to a distal end of the inner sleeve and has an annular dielectric portion and a circumferentially adjacent annular metal portion having an inner window with circumferentially spaced-apart sharp cutting edges that opens to the axial channel. An active electrode is carried by the annular dielectric portion, and the inner window is circumferentially spaced-part from the active electrode so that the inner window and the active electrode rotate alternately into alignment with the outer window as the inner sleeve is rotated within the outer sleeve.

A fluid management system for use in a tissue resection procedure includes a controller. An inflow pump is operated by the controller and configured to provide fluid inflow through a flow path to a site in patient's body. An outflow pump is operated by the controller and configured to provide fluid outflow through a flow path from the site in patient's body. A motor driven resecting device may be provided for resecting tissue at the site. The controller is configured to actuate an inflow pump and an outflow pump in response to various signals and various algorithms are provided to provide malfunction warnings and assure safe operation.

An electrosurgical wand is provided and includes a handle and an elongate shaft coupled to the handle and extending distally from the handle along an axis. An active electrode is disposed at a distal end of the electrosurgical wand. A return electrode abuts the elongate shaft and extends along and annularly about the axis. The return electrode has a top side adjacent the active electrode and an opposite bottom side and defines a notch. A support member is disposed in the notch between the electrodes and transitions curvilinearly from the notch to define a front surface extending laterally across and axially from the return electrode. The front surface tapers downwardly from the active electrode to define a first portion defining a first convex outer surface and also extends toward the bottom side of the return electrode to define a second portion defining a second convex outer surface.

A method for tissue coagulation includes using a device that has a plurality of conductive elements and a return electrode which is in the form of a grid. A moving mechanism moves the conductive elements so that the tip of each conductive element protrudes distally through the spaces of the grid of the return electrode into a tissue at a first depth. A first radiofrequency (RF) voltage is applied between the tips of each conductive element, which are at the first depth, and the return electrode. The conductive elements are then moved from the first depth to second depth of protrusion, and a second RF voltage is applied between the tips of each conductive element at the second depth and the return electrode.

A medical device includes a shaft including a distal end including a passive electrode that defines a central opening extending through the passive electrode, and an active electrode within the central opening. The active electrode is movable between at least an extended position in which the active electrode does not contact the passive electrode, and a retracted position in which the active electrode contacts the passive electrode.

Described herein are various implementations of systems and methods for accessing and modulating tissue (for example, systems and methods for accessing and ablating nerves or other tissue within or surrounding a vertebral body to treat chronic lower back pain). Assessment of vertebral endplate degeneration or defects (e.g., pre-Modic changes) to facilitate identification of treatment sites and protocols are also provided in several embodiments. Several embodiments comprise the use of biomarkers to confirm or otherwise assess ablation, pain relief, efficacy of treatment, etc. Some embodiments include robotic elements for, as an example, facilitating robotically controlled access, navigation, imaging, and/or treatment.

A cooled radio-frequency (RF) ablation probe is provided. The RF ablation probe includes a first tubular portion defining at least part of an internal cavity for circulating coolant through the cooled RF ablation probe; a second tubular portion surrounding the first tubular portion along a first portion of the length of the cooled RF ablation probe; a third tubular portion surrounding the second tubular portion along a second portion of the length of the cooled RF ablation probe; and a fourth tubular portion surrounding the third tubular portion along a third portion of the length of the cooled RF ablation probe. A gap is defined between the third tubular portion and the fourth tubular portion that can be filled with air or a vacuum can be formed in the gap to insulate one or more thermocouples attached to the fourth tubular portion from the coolant in the internal cavity.

An electrosurgical system can include an electrosurgical generator, a feedback circuit or controller, and an electrosurgical tool. The feedback circuit can provide an electrosurgery endpoint by determining the phase end point of a tissue to be treated. The electrosurgical system can include more than one electrosurgical tool for different electrosurgical operations and can include a variety of user interface features and audio/visual performance indicators. The electrosurgical system can also power conventional bipolar electrosurgical tools and direct current surgical appliances.