Abstract: The present invention provides methods, systems, and kits for protecting body tissues which are adjacent to tissues undergoing thermal treatment. The methods, systems, and kits are useful for thermally ablating tumors which lie at or near the surface of an organ, such as the kidney, pancreas, stomach, spleen, and particularly the liver. In radiofrequency and electrosurgical treatment, electrodes may penetrate and heat may dissipate into surrounding tissues and into tissue adjacent to the target organ, thus causing unwanted tissue damage. These risks and others may be lessened or avoided with the use of an interface shield between the target region and adjacent body tissues to shield surrounding organs and tissue from treatment effects.

Abstract: Methods for heating tissue by delivering radio frequency energy through tissue electrodes comprise controlling energy delivery so that an abrupt increase in impedance between the electrodes and the tissue is observed, typically in the form of an abrupt decrease in power delivered to the electrodes. The power at which the impedance increases and/or the time required to induce such an increase in impedance, are relied on to determine acceptable ranges to achieve a maximum sustainable delivery of radio frequency energy to the tissue consistent with complete, rapid, and uniform heating of the tissue.

Abstract: A probe system for volumetric tissue heating and ablation comprises a cannula having a multiple electrode component reciprocatably mounted therein. Individual electrodes within the array have spring memory so that they assume a radially outward, arcuate configuration as they are advanced distally from the cannula. Preferably, the electrodes fully evert as they are advanced from the cannula. Prior to deployment, the electrodes are constrained within a lumen of the cannula. The electrodes are maintained with a uniform circumferential spacing by confining them within an annular envelope defined by a core member within the cannula lumen, by providing electrodes having asymmetric cross-sectional geometries, and/or by nesting the electrodes closely together. Optionally, a cutting current may be applied to the electrodes as they are advanced.

Abstract: Methods for heating tissue by delivering radio frequency energy through tissue electrodes comprise controlling energy delivery so that an abrupt increase in impedance between the electrodes and the tissue is observed, typically in the form of an abrupt decrease in power delivered to the electrodes. The power at which the impedance increases and/or the time required to induce such an increase in impedance, are relied on to determine acceptable ranges to achieve a maximum sustainable delivery of radio frequency energy to the tissue consistent with complete, rapid, and uniform heating of the tissue.

Abstract: Methods for heating tissue by delivering radio frequency energy through tissue electrodes comprise controlling energy delivery so that an abrupt increase in impedance between the electrodes and the tissue is observed, typically in the form of an abrupt decrease in power delivered to the electrodes. The power at which the impedance increases and/or the time required to induce such an increase in impedance, are relied on to determine acceptable ranges to achieve a maximum sustainable delivery of radio frequency energy to the tissue consistent with complete, rapid, and uniform heating of the tissue.

Abstract: Body lumens such as blood vessels are selectively occluded by applying radiofrequency voltage to a vaso-occlusive coil (100) at the target site (TS) and generating a thermal reaction to induce fibrogenic occlusion of the blood vessel (BV) around the vaso-occlusive coil. The radiofrequency current is usually sufficient to induce thermal damage to the luminal wall and to coagulate the surrounding blood, thereby initiating clotting and subsequent fibrosis to permanently occlude the lumen. The invention also includes a method for endoluminally deploying the vaso-occlusive coil and preventing migration of the coil from of the target site.

Abstract: A system for treating a target region in tissue beneath a tissue surface comprises a probe for deploying an electrode array within the tissue and a surface electrode for engaging the tissue surface above the treatment site. Preferably, surface electrode includes a plurality of tissue-penetrating elements which advance into the tissue, and the surface electrode is removably attachable to the probe. The tissue may be treated in a monopolar fashion where the electrode array and surface electrode are attached to a common pole on an electrode surgical power supply and powered simultaneously or successively, or in a bipolar fashion where the electrode array and surface electrode are attached to opposite poles of the power supply. The systems are particularly useful for treating tumors and other tissue treatment regions which lie near the surface.

Abstract: Improved methods and apparatus for monitoring the delivery of radio frequency (RF) energy from electrodes disposed in tissue for inducing hyperthermia and other purposes. In one form, an impedance display of a power supply comprises an array of discrete light elements, where the number of light elements illuminated increases in response to a percentage increase in calculated impedance. The array of light elements is typically arranged in a non-linear pattern where a left hand portion of the array extends horizontally while a right hand portion extends upwardly. The display allows an operator to visually monitor abrupt increases in impedance between an RF instrument and a target tissue. Such increases are used to determine acceptable power ranges to achieve a maximum sustainable delivery of radio frequency energy to the tissue consistent with complete, rapid, and uniform heating of the tissue.

Abstract: Body lumens such as blood vessels are selectively occluded by mechanically collapsing the blood vessel and subsequently applying energy or other occlusive conditions within or adjacent the collapsed region. For example, vessel collapsing mechanisms can include spreadable opposed elements, reciprocating jaw mechanisms having penetrating elements, and devices for applying negative pressure to collapse the blood vessel. One or more electrodes can be used in a monopolar or bipolar fashion to apply radiofrequency or other energy to the body lumen in the region where it has been collapsed.

Abstract: A probe system for volumetric tissue heating and ablation comprises a cannula having a multiple electrode component reciprocatably mounted therein. Individual electrodes within the array have spring memory so that they assume a radially outward, arcuate configuration as they are advanced distally from the cannula. Preferably, the electrodes fully evert as they are advanced from the cannula. Prior to deployment, the electrodes are constrained within a lumen of the cannula. The electrodes are maintained with a uniform circumferential spacing by confining them within an annular envelope defined by a core member within the cannula lumen, by providing electrodes having asymmetric cross-sectional geometries, and/or by nesting the electrodes closely together. Optionally, a cutting current may be applied to the electrodes as they are advanced.

Abstract: Methods for heating tissue by delivering radio frequency energy through tissue electrodes comprise controlling energy delivery so that an abrupt increase in impedance between the electrodes and the tissue is observed, typically in the form of an abrupt decrease in power delivered to the electrodes. The power at which the impedance increases and/or the time required to induce such an increase in impedance, are relied on to determine acceptable ranges to achieve a maximum sustainable delivery of radio frequency energy to the tissue consistent with complete, rapid, and uniform heating of the tissue.

Abstract: Body lumens such as blood vessels are selectively occluded by mechanically collapsing the blood vessel and subsequently applying energy or other occlusive conditions within or adjacent the collapsed region. For example, vessel collapsing mechanisms can include spreadable opposed elements, reciprocating jaw mechanisms having penetrating elements, and devices for applying negative pressure to collapse the blood vessel. One or more electrodes can be used in a monopolar or bipolar fashion to apply radiofrequency or other energy to the body lumen in the region where it has been collapsed.