An electrosurgical apparatus and method for performing thermal treatment in the gastrointestinal tract, e.g. to ablate duodenal mucosal tissue. The apparatus comprises an instrument having a flexible cable and an applicator suitable for use with a gastroscope, which can be deployed within a patient to delivery energy in a targeted or otherwise controllable manner. The applicator can deliver microwave energy by radiation. The direct and depth-limited nature of microwave energy can be make it more effective than treatments that rely on thermal conduction. The applicator may include a radially extendable portion arranged to move an microwave energy delivery structure into contact with duodenal mucosal tissue at the treatment region. The applicator may comprise any of a balloon, bipolar radiator, movable paddle, and rotatable roller element.

A variable-length microwave ablation probe is provided. The probe is configured to have a range of resonant frequencies. The probe includes a microwave antenna, an outer conductor, and a cap. The probe further includes a radiation window that is at least partially transparent to microwave energy. The distal boundary of the outer conductor or the proximal boundary of the cap varies in distance from the probe distal end. The probe can have a choke length, an arm length, a radiating portion length, and a cap length. The lengths can each affect the resonant frequency of the antenna. Some examples provide a variable choke length, a variable arm length, a variable radiating portion length, and/or a variable cap length.

An electrosurgical device (10) operable to deliver microwave energy to cause targeted tissue ablation is provided. The electrosurgical device (10) comprises an antenna (26), a reflector (30), and a dielectric material (34) disposed therebetween. The selection of the dielectric material (30) and the relative positioning of the antenna (26) and the reflector (30) provide impedance matching between the antenna (26) and a transmission line (12) so as to minimize heating along the length of the device (10) during use.

Various embodiments provide an electrosurgical instrument comprising: a flexible coaxial transmission line arranged to convey microwave energy; a radiating tip portion connected at a distal end of the flexible coaxial transmission line and configured to receive the microwave energy, the radiating tip portion comprising: a distal coaxial transmission line for conveying the microwave energy; and a needle tip mounted at a distal end of the distal coaxial transmission line, the needle tip being arranged to deliver the microwave energy into biological tissue; and a heat sink mounted at an interface between the flexible coaxial transmission line and radiating tip portion. The heat sink is in thermal communication with a proximal end of the distal coaxial transmission line and configured to draw thermal energy from the radiating tip portion. Also, a maximum outer diameter of the radiating tip portion is smaller than an outer diameter of the flexible coaxial transmission line. An associated electrosurgical system is also disclosed.

A microwave ablation system comprises a generator, a generator cable, and a microwave ablation device. The generator comprises a generator output port having a generator output port impedance. The generator cable has a generator cable impedance that is matched to the generator output port impedance within a degree of tolerance within a predetermined frequency range. The microwave ablation device comprises a coaxial cable that has a coaxial cable impedance and is coupled to the generator output port by way of the generator cable. Within the predetermined frequency range, the coaxial cable impedance is lower than at least one of the generator output port impedance or the generator cable impedance by at least a predetermined amount that exceeds the degree of tolerance.

A variable-length microwave ablation probe is provided. The probe is configured to have a range of resonant frequencies. The probe includes a microwave antenna, an outer conductor, and a cap. The probe further includes a radiation window that is at least partially transparent to microwave energy. The distal boundary of the outer conductor or the proximal boundary of the cap varies in distance from the probe distal end. The probe can have a choke length, an arm length, a radiating portion length, and a cap length. The lengths can each affect the resonant frequency of the antenna. Some examples provide a variable choke length, a variable arm length, a variable radiating portion length, and/or a variable cap length.

The present invention discloses medical systems and methods adapted for the delivery of various medical components such as microwave antennas within or on a body for performing one or more medical procedures. Several embodiments herein disclose medical systems comprising a combination of one or more medical components and one or more elongate steerable or non-steerable arms that are adapted to mechanically manipulate the one or more medical components. Several embodiments of microwave antennas are disclosed that comprise an additional diagnostic or therapeutic modality located on or in the vicinity of the microwave antennas.

A microwave ablation device including a cable assembly configured to connect a microwave ablation device to an energy source and a feedline in electrical communication with the cable assembly. The microwave ablation device further includes a balun on an outer conductor of the feedline, and a temperature sensor on the balun sensing the temperature of the balun.

An ablation probe tip 100 having a shaft 102 with an insertion end 104 and an annular aperture 120 near the insertion end 104. A center of ablation 124 is located within the shaft 102 and surrounded by the annular aperture shaft 102. The ablation probe tip 100 may be part of an ablation probe system 50 that includes an ablation source 60 that provides ablation means 62 to the ablation probe tip 100. The center of ablation 124 is a focal region from which the ablation means 62 radiates through the annular aperture 120 to form an ablation zone 150, 160, 170. The system 50 has at least one intra-operative control selected from the group of: ablation zone positioning control, ablation zone shaping control, ablation center control, ablation zone temperature control, guided ablation volume/diameter control, and power loading control.

The present invention discloses medical systems and methods adapted for the delivery of various medical components such as microwave antennas within or on a body for performing one or more medical procedures. Several embodiments herein disclose medical systems comprising a combination of one or more medical components and one or more elongate steerable or non-steerable arms that are adapted to mechanically manipulate the one or more medical components. Several embodiments of microwave antennas are disclosed that comprise an additional diagnostic or therapeutic modality located on or in the vicinity of the microwave antennas.