A microwave ablation antenna assembly (20) incorporates an improved choke assembly (40) which provides the antenna assembly (20) with both a largely spherical ablation pattern and an improved impedance matching characteristic.

Provided in accordance with aspects of the present disclosure is a microwave ablation system including an introducer having a lumen therethrough, a stylus configured for slidable engagement within the lumen of the introducer, and a microwave ablation antenna configured to deliver energy to a target during an ablation procedure, wherein the microwave ablation antenna is configured for slidable engagement within the lumen of the introducer.

A method for forming a resonating structure within a body lumen, the method including advancing a flexible microwave catheter into a body lumen of a patient, the flexible microwave catheter including a radiating portion at the distal end of the flexible microwave catheter, the radiating portion configured to receive microwave energy, and at least one centering device proximate the radiating portion configured to deploy radially outward from the flexible microwave catheter; positioning the radiating portion near tissue of interest; deploying the at least one centering device radially outward from the flexible microwave catheter within the body lumen such that a longitudinal axis of the radiating portion is substantially parallel with and at a fixed distance from a longitudinal axis of the body lumen near the targeted tissue; and delivering microwave energy to the radiating portion such that a circumferentially balanced resonating structure is formed with the body lumen.

Embodiments of the invention provide an energy conveying structure for delivering RF and/or microwave energy to an electrosurgical instrument, where the energy conveying structure is incorporated into an insertion tube of a surgical scoping device (e.g. endoscope, laparoscope or the like). The insertion tube is a flexible conduit that is introduced into a patient's body during an invasive procedure, and can include an instrument channel and an optical channel. The energy conveying structure may be a layered coaxial structure that formed a liner that fits within the scoping device, e.g. within an instrument channel. Alternatively, the energy conveying structure may be a coaxial structure integrally formed as part of the flexible conduit.

A radiation applicator with a dielectric body (2) surrounding the antenna. The dielectric body (2) is comprised of three sections (3, 4 and 5) with different dielectric constants to provide broad-band matching of the applicator to surrounding material. Washers (10) and (11) are mounted on the antenna to act as reflectors.

An electrosurgical resection instrument for applying to biological tissue radiofrequency electromagnetic energy has a protective hull comprising a shaped piece of dielectric material mounted to cover an underside of an instrument tip of the instrument. The protective hull acts as a shield to protect tissue that may lie under the instrument tip from damage during treatment. The instrument may be particularly useful in procedures performed in a gastrointestinal tract, where bowel perforation is a concern, or in the pancreas, where damage to the portal vein or the pancreatic duct may occur when a tumor or other abnormality is being resected, dissected or removed.

A conduit assembly for transmitting energy between an electrosurgical energy generator and an energy delivering device comprises a first cable sub-assembly including a cable having a flexibility and an energy attenuation; a second cable sub-assembly including a cable having a flexibility and an energy attenuation; wherein the flexibility of the cable of the first cable sub-assembly is less than the flexibility of the cable of the second cable sub-assembly; and wherein the energy attenuation of the cable of the first cable sub-assembly is less than the energy attenuation of the cable of the second cable sub-assembly.

An ablation system for directing energy to a target volume of tissue is provided. The ablation system comprises an ablation antenna probe including at least one radiating portion configured to output electromagnetic radiation and at least one electromagnetic shielding reflector configured for removable positioning on the antenna probe. The at least one electromagnetic shielding reflector is configured to block electromagnetic radiation from the at least one radiating portion through the at least one electromagnetic shielding reflector such that a particular directionality of the electromagnetic radiation from the at least one radiation portion to a target volume of tissue is achieved.

An electrosurgical device (10) is provided that is operable to deliver microwave energy within a controlled angular expanse to cause targeted tissue ablation. The device (10) comprises a blocking or reflecting material such as cylindrical members (34) that are laterally spaced from the antenna (20) that is operable to emit the microwave energy. The reflecting material creates regions in and/or surrounding the device into which sensors (51), such as thermocouple wires, may be placed to monitor a condition associated with the device or the patient's body.

An electrosurgical device having a radiating tip portion for delivering electromagnetic energy to biological tissue, where the electrosurgical device is disposed in a catheter. The electrosurgical device is movable relative to the catheter between a deployed position where the radiating tip portion is exposed and a retracted position where the radiating tip portion is contained within the catheter. In this manner, the radiating tip portion may be retracted until the moment when it is to be used. This may facilitate insertion of the device through an instrument channel of a surgical scoping device. In particular, this may prevent the radiating tip portion from catching on the instrument channel when the device is inserted into the instrument channel, which could cause damage to the instrument channel and/or radiating tip portion.