Electrosurgical instrument for ablation and resection

An electrosurgical instrument for delivering radiofrequency (RF) electromagnetic (EM) energy and microwave EM energy for resection and ablation of biological tissue, the instrument comprising:

• an energy conveying cable structure comprising:
• a coaxial transmission line for conveying microwave energy, the coaxial transmission line comprising an inner conductive layer, an outer conductive layer and a dielectric layer separating the inner conductive layer from the outer conductive layer, wherein the inner conductive layer is formed around a hollow longitudinal passage along the cable structure;
• and
• a transmission line for conveying radiofrequency energy along the hollow longitudinal passage;
• and
• an instrument tip at a distal end of the energy conveying cable structure, the instrument tip comprising:
• a dielectric tip element extending longitudinally beyond a distal end of an outer conductor, wherein an inner conductor extends longitudinally beyond the distal end of the outer conductor within the dielectric tip element to form a microwave radiator;
• and
• an active electrode and a return electrode mounted at a distal end of the dielectric tip element, wherein the active electrode and the return electrode are connected to the transmission line to support an RF field therebetween at the distal end of the dielectric tip element, wherein the transmission line for conveying the radiofrequency energy is a pair of wires extending through the hollow longitudinal passage, wherein the longitudinal passage extends through the dielectric tip element to provide a fluid flow path through the instrument.

An electrosurgical instrument for delivering radiofrequency RF) electromagnetic (EM) energy and microwave EM energy for resection and ablation of biological tissue, the instrument comprising:

• an energy conveying cable structure comprising:
• a coaxial transmission line for conveying microwave energy, the coaxial transmission line comprising an inner conductive layer, an outer conductive layer and a dielectric layer separating the inner conductive layer from the outer conductive layer, wherein the inner conductive layer is formed around a hollow longitudinal passage along the cable structure;
• and
• a transmission line for conveying radiofrequency energy along the hollow longitudinal passage;
• and
• an instrument tip at a distal end of the energy conveying cable structure, the instrument tip comprising:
• a dielectric tip element extending longitudinally beyond a distal end of an outer conductor, wherein an inner conductor extends longitudinally beyond the distal end of the outer conductor within the dielectric tip element to form a microwave radiator;
• and
• an active electrode and a return electrode mounted at a distal end of the dielectric tip element, wherein the active electrode and the return electrode are connected to the transmission line to support an RF field therebetween at the distal end of the dielectric tip element, wherein the transmission line for conveying the radiofrequency energy is a pair of wires extending through the hollow longitudinal passage, wherein the dielectric tip element is ceramic.

An electrosurgical instrument for delivering radiofrequency (RF) electromagnetic (EM) energy and microwave EM energy for resection and ablation of biological tissue, the instrument comprising:

• an energy conveying cable structure comprising:
• a coaxial transmission line for conveying microwave energy, the coaxial transmission line comprising an inner conductive layer, an outer conductive layer and a dielectric layer separating the inner conductive layer from the outer conductive layer, wherein the inner conductive layer is formed around a hollow longitudinal passage along the cable structure;
• and
• a transmission line for conveying radiofrequency energy along the hollow longitudinal passage;
• and
• an instrument tip at a distal end of the energy conveying cable structure, the instrument tip comprising:
• a dielectric tip element extending longitudinally beyond a distal end of an outer conductor, wherein an inner conductor extends longitudinally beyond the distal end of the outer conductor within the dielectric tip element to form a microwave radiator;
• and
• an active electrode and a return electrode mounted at a distal end of the dielectric tip element, wherein the active electrode and the return electrode are connected to the transmission line to support an RF field therebetween at the distal end of the dielectric tip element, wherein the transmission line for conveying the radiofrequency energy is a pair of wires extending through the hollow longitudinal passage;
• wherein the electrosurgical instrument has a diplexer connected at a proximal end of the energy conveying cable structure.

An electrosurgical instrument for delivering radiofrequency (RF) electromagnetic (EM) energy and microwave EM energy for resection and ablation of biological tissue, the instrument comprising:

• a coaxial transmission line for conveying the RF EM energy and the microwave EM energy, the coaxial transmission line comprising an inner conductive layer, an outer conductive layer and a dielectric layer separating the inner conductive layer from the outer conductive layer;
• and
• an instrument tip at a distal end of the energy conveying cable structure, the instrument tip comprising:
• a first conductive hemisphere electrically connected to the inner conductive layer;
• a second conductive hemisphere electrically connected to the outer conductive layer;
• and
• a planar dielectric layer located in a physical separation gap between the first conductive hemisphere and the second conductive hemisphere, wherein the first conductive hemisphere and the second conductive hemisphere are configured to:
• radiate the microwave EM energy as a substantially spherical field, and provide respectively an active electrode and a return electrode on opposing sides of the separation gap for delivering the RF EM energy,
• wherein the coaxial transmission line includes a fluid flow passage for conveying a fluid to the instrument tip.