Abstract: A catheter includes a cryoablation tip with an ablation assembly for heating tissue. The cryoablation tip may be implemented with a cooling chamber and have an RF electrode at its distal end. The electrode may be operated to warm cryogenically-cooled tissue, or the coolant may be controlled in combination with an RF treatment regimen to enhance the lesion size, speed or placement of multi-lesion or single lesion cycles. In one embodiment a microwave energy source operates to extend beyond the thermal conduction depth, or penetrate the ice ball and be absorbed in tissue beyond an ice boundary, thus extending a dimension of treatment. Also, the cooling and application of RF energy can be controlled to position the ablation region away from the surface contacted by the electrode thereby leaving surface tissue unharmed while ablating at depth or to provide an ablation band of greater uniformity with increasing depth.

Abstract: A method is disclosed for treating heart and vascular tissue with cryotreatment. A medical instrument, such as a catheter is positioned to contact a target region of cardiac tissue such as the epicardial tissue. The instrument or catheter provided includes a cryotreatment element that has thermally-transmissive properties. The cryotreatment element may be a cryochamber for enclosing the flow of a fluid refrigerant therein. The cryotreatment element is disposed at the situs of heart or vascular tissue to be treated, usually by piercing the epicardium sac via an opening in the patient's body. A refrigerant flow within the cryochamber creates endothermic cooling with respect to the targeted heart or vascular tissue, inducing hypothermia and forming iceballs proximate the tissue. The cooling may be reversible and non-permanent, or may be permanent leading to cell death, necrosis, apoptosis and/or surgical excision or ablation of tissue.

Abstract: A method is disclosed for treating heart and vascular tissue with cryotreatment. A medical instrument, such as a catheter is positioned to contact a target region of cardiac tissue such as the epicardial tissue. The instrument or catheter provided includes a cryotreatment element that has thermally-transmissive properties. The cryotreatment element may be a cryochamber for enclosing the flow of a fluid refrigerant therein. The cryotreatment element is disposed at the situs of heart or vascular tissue to be treated, usually by piercing the epicardium sac via an opening in the patient's body. A refrigerant flow within the cryochamber creates endothermic cooling with respect to the targeted heart or vascular tissue, inducing hypothermia and forming iceballs proximate the tissue. The cooling may be reversible and non-permanent, or may be permanent leading to cell death, necrosis, apoptosis and/or surgical excision or ablation of tissue.

Abstract: A catheter includes a cryoablation tip with an electrically-driven ablation assembly for heating tissue. The cryoablation tip may be implemented with a cooling chamber through which a controllably injected coolant circulates to lower the tip temperature, and having an RF electrode at its distal end. The RF electrode may be operated to warm cryogenically-cooled tissue, or the coolant may be controlled to conductively cool the tissue in coordination with an RF treatment regimen, allowing greater versatility of operation and enhancing the lesion size, speed or placement of multi-lesion treatment or single lesion re-treatment cycles. In one embodiment a microwave energy source operates at a frequency to extend beyond the thermal conduction depth, or to penetrate the cryogenic ice ball and be absorbed in tissue beyond an ice boundary, thus extending the depth and/or width of a single treatment locus.

Abstract: A catheter includes a cryoablation tip with an electrically-driven ablation assembly for heating tissue. The cryoablation tip may be implemented with a cooling chamber through which a controllably injected coolant circulates to lower the tip temperature, and having an RF electrode at its distal end. The RF electrode may be operated to warm cryogenically-cooled tissue, or the coolant may be controlled to conductively cool the tissue in coordination with an RF treatment regimen, allowing greater versatility of operation and enhancing the lesion size, speed or placement of multi-lesion treatment or single lesion re-treatment cycles. In one embodiment a microwave energy source operates at a frequency to extend beyond the thermal conduction depth, or to penetrate the cryogenic ice ball and be absorbed in tissue beyond an ice boundary, thus extending the depth and/or width of a single treatment locus.

Abstract: A cryosurgical system including a housing having a front portion and a rear portion. The front portion and rear portion are connectable to support a fluid supply. A control unit attached to the front portion, and has a regulator assembly connecting the fluid supply to the control unit. A medical device is connected to the control unit, the medical device including a handle, a shaft, and a thermally-transmissive region. The handle, the shaft, and the thermally-transmissive region defining a fluid pathway through the handle, shaft, and thermally-transmissive region. The shaft is malleable to retain a first shape until manipulated to a second shape.

Abstract: A method of promoting blood vessel growth includes the steps of providing a cryocatheter having a thermally transmission region; placing the cryocatheter proximate an area of tissue to be treated; cooling the thermally transmissive region of the cryocatheter proximate the area of tissue to a temperature sufficient to injure the area of tissue; allowing the area of tissue to warm; and removing the cryocatheter from the area of tissue. Prior, during or after the cooling step, the area of tissue can be mechanically traumatized, and drugs can be injected into the tissue.

Abstract: A cryocatheter for treatment of tissue has a tip adapted to provide a signal indicative of the quality and/or orientation of the tip contact with surrounding tissue. In one embodiment, a signal conductor extends through the catheter to the tip and connects to a thermally and electrically conductive shell or cap that applies an RF current to the region of tissue contacted by the tip. The tissue impedance path between the signal lead and a surface electrode mounted on the patient's skin is monitored to develop a quantitative measure of tissue contact at the distal tip, which is preferably displayed on the screen of a catheter monitoring console. In yet a further embodiment, the catheter is provided with a split tip having temperature monitoring sensors, such as thermistors, mounted on opposed halves of the tip so as to sense temperature on two sides of the catheter axis.

Abstract: A cryosurgical system including a housing having a font portion and a rear portion. The front portion and rear portion are connectable to support a fluid supply. A control unit attached to the front portion, and has a regulator assembly connecting the fluid supply to the control unit. A medical device is connected to the control unit, the medical device including a handle, a shaft, and a thermally-transmissive region. The handle, the shaft, and the thermally-transmissive region defining a fluid pathway through the handle, shaft, and thermally-transmissive region. The shaft is malleable to retain a first shape until manipulated to a second shape.

Abstract: A method of promoting blood vessel growth includes the steps of providing a cryocatheter having a thermally transmission region; placing the cryocatheter proximate an area of tissue to be treated; cooling the thermally transmissive region of the cryocatheter proximate the area of tissue to a temperature sufficient to injure the area of tissue; allowing the area of tissue to warm; and removing the cryocatheter from the area of tissue. Prior, during or after the cooling step, the area of tissue can be mechanically traumatized, and drugs can be injected into the tissue.

Abstract: A cryocatheter includes a catheter body defining a coolant flow path, a catheter tip exposed to the coolant flow path, and a heating element associated with the catheter tip. The heating element can be disposed entirely or partially within the catheter tip. Alternatively, the heating element can be exterior to the catheter tip. The heating element can include an electrically resistive element.

Abstract: A method of promoting blood vessel growth includes the steps of providing a cryocatheter having a thermally transmission region; placing the cryocatheter proximate an area of tissue to be treated; cooling the thermally transmissive region of the cryocatheter proximate the area of tissue to a temperature sufficient to injure the area of tissue; allowing the area of tissue to warm; and removing the cryocatheter from the area of tissue. Prior, during or after the cooling step, the area of tissue can be mechanically traumatized, and drugs can be injected into the tissue.

Abstract: A method for inhibiting restenosis includes applying cryogenic energy to a treatment site for a predetermined amount of time. In one embodiment, the treatment site, e.g., a region of an artery dilated by means of a balloon catheter, is cooled to a temperature of about minus fifty degrees Celsius for about two minutes. The application of cryogenic energy inhibits restenosis of the dilated region of the vessel.

Abstract: A cryogenic catheter includes a flexible member having an elongate, thermally-transmissive region and a cryogenic fluid path through the flexible member to the thermally-transmissive region. The thermally-transmissive region can be deformable from a linear configuration to an arcuate configuration and can include multiple thermally-transmissive elements having a first side exposed to the cryogenic fluid path and a second side exposed to points exterior to the flexible member. The thermally-transmissive elements can be rigid or flexible longitudinal strips. Alternatively, annular, cylidrical, or wedge-shaped metallic structures disposed in a spaced-apart relationship can define the thermally-transmissive region. In other embodiments the thermally-transmissive region is defined by a helical coil that is at least partially embedded in the flexible member. The helical coil can also define at least a portion of the cryogenic fluid path through the flexible member and include a gas expansion or boiling chamber.

Abstract: A cryogenic catheter includes a flexible member having an elongate, thermally-transmissive region and a cryogenic fluid path through the flexible member to the thermally-transmissive region. The thermally-transmissive region can be deformable from a linear configuration to an arcuate configuration and can include multiple thermally-transmissive elements having a first side exposed to the cryogenic fluid path and a second side exposed to points exterior to the flexible member. The thermally-transmissive elements can be rigid or flexible longitudinal strips. Alternatively, annular, cylindrical, or wedge-shaped metallic structures disposed in a spaced-apart relationship can define the thermally-transmissive region. In other embodiments the thermally-transmissive region is defined by a helical coil that is at least partially embedded in the flexible member. The helical coil can also define at least a portion of the cryogenic fluid path through the flexible member and include a gas expansion or boiling chamber.