Described here are devices and methods for treating hypertension by forming a fistula between two blood vessels to reduce blood pressure of a patient. The fistula may be formed using a catheter having an electrode that is placed in a first blood vessel. In some instances, a desired amount of blood pressure is determined. In other instances, the hypertension is drug resistant hypertension.

A method for carrying out a cardiac procedure includes: a. via an inferior artery, advancing a perforating tip of a perforation device towards an aorta; b. positioning the perforating tip adjacent a wall of the aorta, proximate a left pulmonary artery; and c. advancing the perforating tip to perforate through the wall of the aorta and then through a wall of the left pulmonary artery, to create a pathway between the aorta and the left pulmonary artery.

A tissue-spreader assembly is configured to be selectively inserted into a patient having a first biological tissue and a second biological tissue, and to be maneuvered proximate to the second biological tissue. The tissue-spreader assembly is also configured to selectively engage, at least in part, an area of the second biological tissue without engaging the first biological tissue. The tissue-spreader assembly is also configured to selectively spread, at least in part, the area of the second biological tissue, and maintain the area of the second biological tissue in a spread-apart condition after the tissue-spreader assembly, in use, selectively engages, at least in part, the area of the second biological tissue.

The limiting device includes a clamping portion and a movable portion; the clamping portion and the movable portion are both annular structures, two ends of the clamping portion and the movable portion are respectively connected to form a connected double-ring structure, and the ring diameter of the movable portion is larger than that of the clamping portion. The limiting device is disposed on a core rod, the clamping portion and the core rod are in interference fit, and the movable portion and the core rod are in clearance fit. When the movable portion cooperates with the core rod, the limiting device may slide relative to the core rod; when the clamping portion cooperates with the core rod, the limiting device and the core rod are in a fixed state, and the limiting device cannot slide relative to the core rod, thus achieving the purpose of limiting.

An electrosurgical instrument is disclosed, having a first electrode having a planar face, a second electrode; an electrically insulative body, a fluid channel, a conductive wire, and a tubular seal. The tubular seal prevents saline from extending into a gap between the wire and the electrically insulative body of the instrument. The tubular seal is disposed around the wire, and extends between the wire and the body.

An electrode assembly for an electrosurgical instrument includes a housing having an active electrical connector and a return electrical connector configured to operably engage a distal end of an electrosurgical instrument shaft, the housing encapsulating an elongated return electrode and a pair of insulative tubes configured to house a wire-like active electrode. The elongated return electrode includes a clevis at a distal end thereof and operably engages to the return electrical connector at a proximal end thereof. The wire-like active electrode operably engages at one end to the active electrical connector. A donut-like insulator is operably engaged to the clevis of the elongated return electrode and is configured to support the wire-like active electrode therearound. A tensioning mechanism is configured to operably engage an opposite end of the wire-like electrode and tension the wire-like active electrode about the donut-like insulator during assembly.

A cable assembly includes a rigid portion, a flexible central portion, and a radiating portion. The rigid portion is configured to couple to a source of electrosurgical energy and to prevent fluid ingress towards the source of electrosurgical energy. The flexible central portion extends from the rigid portion and includes an inner conductor, a dielectric disposed about the inner conductor, and a conductive braid disposed about the dielectric. The radiating portion extends from the central portion and is configured to deliver electrosurgical energy to tissue.

An electrode unit includes: an electrode supporting member provided with a pair of distal end rigid members, surfaces of which are covered by an electrically insulating material, and an elastic region having lower bending rigidity than bending rigidity of each of the pair of distal end rigid members; an electrode configured with electrode bodies respectively protruding downward from the pair of distal end rigid members of the electrode supporting member and a spanning portion that spans between respective lower end portions of the electrode bodies; and an operation member provided in a proximal end rigid member, and configured to move relative to the proximal end rigid member to cause the electrode to move in a direction in which the electrode protrudes relative to the distal end rigid members.

A method for removing tissues may comprise disposing a tissue resection device at a target tissue site, causing the tissue resection device to resect a core of tissue from the target tissue site, removing the core of tissue from the body, wherein the removing the core of tissue from the body creates a core cavity at the target tissue site.

Described here are devices, systems and methods for forming a fistula between two blood vessels. Generally, the systems may comprise a first catheter which may comprise a fistula-forming element. The fistula-forming element may comprise one or more electrodes, mechanical cutting elements, laser sources, or combinations thereof, and may be used to assist in fistula formation. In some instances, a system may comprise a second catheter, which may comprise a fistula-forming element. One or more of the catheters may comprise one or more markers, magnetic alignment elements, and/or one shape-changing elements.