Cryocath Technologies Inc.

Medtronic Cryocath LP

Steven G Arless

Dan Wittenberger

Marwan Abboud

Fredric L Milder

Sean Carroll

Daniel Nahon

Domenic N Santoianni

John W Lehmann

Kenneth A Spector

Philippe Marchand

Claudia Lueckge

Mathieu-Philippe Aubert

Marc Dubuc

Richard Gallo

Jean-Pierre Lalonde

Teresa Ann Mihalik

Cristian Petre

George J Klein

Claudia Lückge

Frederic L Milder

Jean-Francois Tanguay

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.

Method of simultaneously freezing and heating tissue for ablation

Catheter with cryogenic and electrical heating ablation

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.

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.

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.

Method and device for epicardial ablation

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. In another embodiment, the cooling and the application of RF energy are both controlled to position the ablation region away from the surface contacted by the electrode, for example to leave surface tissue unharmed while ablating at depth or to provide an ablation band of greater uniformity with increasing depth. The driver or RF energy source may supply microwave energy at a frequency effective to penetrate the ice ball which develops on a cryocatheter, and different frequencies may be selected for preferential absorption in a layer of defined thickness at depth in the nearby tissue. The catheter may operate between 70 and minus 70 degrees Celsius for different tissue applications, such as angioplasty, cardiac ablation and tissue remodeling, and may preset the temperature of the tip or adjacent tissue, and otherwise overlay or delay the two different profiles to tailor the shape or position where ablation occurs or to speed up a treatment cycle.

Catheter with cryogenic and heating ablation

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.

Cryosurgical catheter

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.

Cryogenic method and apparatus for promoting angiogenesis

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. The thermistor signals are processed to determine and display differential temperature between the two sides of the tip, thus revealing which side lies in contact. In yet a further aspect of the first embodiment, two separate and distinct high frequency electrical signals are applied to the two halves of a split metal shell or cap at the tip. Signals received at the surface electrode are filtered into first and second frequency components, and these are processed to determine the relative magnitude of the signal or the impedance of the path for each of the injected signals to determine and display the tissue contact orientation of the catheter. The catheter preferably has two separate cooling chambers within the cooling tip, positioned with one chamber on each side of the axis, and a separate cooling inlet to each chamber is switched on by a valve which directs the flow of coolant to the contact side during active cryotreatment. In another embodiment, the cap provides an RF electrode that may be opposed to the cooling side so that either the cryogenic or the RF ablation side may be rotated into contact to selectively heat or cool, or in representative protocol treat, then thaw, the same tissue site.

Catheter system

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.

Heater control of cryocatheter tip temperature

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.

Method for inhibiting restenosis

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.

Growing community of inventors

Beaconsfield, Canada

Steven G Arless