Disclosed herein are high efficiency surgical devices and methods of using same using radio frequency (RF) electrical power and/or electrically heated filaments to destroy tumors, form lesions, denaturize, desiccate, coagulate and ablate soft tissues, as well as to drill, cut, resect and vaporize soft tissues. According to the principles of this invention, the electrosurgical instruments can be used with externally supplied conductive or non-conductive liquids, as well as without externally supplied liquids, a mode of operation often referred to as “dry field” environment.

A system for treatment target tissue comprises an ablation device and an energy delivery unit. The ablation device comprises an elongate tube with an expandable treatment element. The system delivers a thermal dose of energy to treat the target tissue. Methods of treating target tissue are also provided.

Methods, systems and devices for applying energy to tissue, and more particularly relates to a system for ablating or modifying structures in a body with systems and methods that generate a flow of vapor at a controlled flow rate for applying energy to the body structure.

An intravascular catheter for nerve activity ablation and/or sensing includes one or more needles advanced through supported guide tubes (needle guiding elements) which expand to contact the interior surface of the wall of the renal artery or other vessel of a human body allowing the needles to be advanced though the vessel wall into the extra-luminal tissue including the media, adventitia and periadvential space. The catheter also includes structures which provide radial and lateral support to the guide tubes so that the guide tubes open uniformly and maintain their position against the interior surface of the vessel wall as the sharpened needles are advanced to penetrate into the vessel wall. Electrodes near the distal ends of the needles allow sensing of nerve activity before and after attempted renal denervation. In a combination embodiment ablative energy or fluid is delivered from the needles in or near the adventitia to ablate nerves outside of the media while sparing nerves within the media.

Systems, devices and methods for performing medical procedures in the intestine of a patient are provided. A medical device for performing a treatment and/or a diagnostic procedure can include an elongate shaft assembly comprising at least a shaft assembly first section comprising a distal section of the shaft assembly, and a shaft assembly second section proximal to the first section, and a functional assembly positioned on the shaft assembly first section. Additional sections of the shaft assembly can be included, and each section can comprise a different construction, such as to achieve a different stiffness as described herein. Variable stiffness along the length of the shaft assembly can be provided to aid in translation of the device through the patient's GI tract (e.g. through the stomach and into the small intestine), as described herein.

A system includes an intravascular medical device and a therapeutic medical device. The intravascular medical device includes a heat therapy assembly and an elongated member coupled to the heat therapy assembly. The heat therapy assembly is configured to expand a vessel beyond an initial size of the vessel and deliver energy to a wall of the expanded vessel to heat the wall of the vessel. The therapeutic medical device is communicatively coupled to the heat therapy assembly and configured to control the heat therapy assembly to deliver the energy to ablate smooth muscle cells of the wall of the vessel and substantially denature one or more structural proteins of the wall of the vessel.

Systems, methods and devices for the treatment of tissue are disclosed. A system includes an elongate tube with a distal portion. A treatment element is positioned on the elongate tube distal portion, the treatment element constructed and arranged to treat target tissue. In one embodiment, gastrointestinal tissue is modified for the treatment of diabetes.

An intravascular catheter for peri-vascular and/or peri-urethral tissue ablation includes multiple needles advanced through supported guide tubes which expand around a central axis to engage the interior surface of the wall of the renal artery or other vessel of a human body allowing the injection an ablative fluid for ablating tissue, and/or nerve fibers in the outer layer or deep to the outer layer of the vessel, or in prostatic tissue. The system may also include a means to limit and/or adjust the depth of penetration of the ablative fluid into and beyond the tissue of the vessel wall. The catheter may also include structures which provide radial and/or lateral support to the guide tubes so that the guide tubes expand uniformly and maintain their position against the interior surface of the vessel wall as the sharpened injection needles are advanced to penetrate into the vessel wall.

A cassette for a heated fluid ablation system, comprises a fluid supply lumen receiving an ablation fluid from an external fluid source and a fluid chamber containing a therapeutic agent in combination with an impeller pumping the ablation fluid out of the cassette via to a fluid delivery lumen when the cassette is in a first configuration and pumping the therapeutic agent out of the cassette via the fluid delivery lumen when the cassette is in a second configuration.

Devices, systems, and methods for degassing fluid prior to applying fluid to a treatment site during ablation therapy are provided. In one embodiment, an ablation system can include an elongate body, an ablation element, a heating assembly, and a fluid source. Fluid in the fluid source can be at least partially degassed prior to being provided as part of the system, or, in some embodiments, a degassing apparatus can be provided that can be configured to degas fluid within the system prior to applying the fluid to the treatment site. The degassing apparatus can include one or more gas-permeable and fluid-impermeable tubes disposed therein, which can allow gas to be removed from fluid passing through the apparatus. Other exemplary devices, systems, and methods are also provided.