Cryotreatment devices and methods of forming conduction blocks

A medical device for inducing controlled necrosis at a target site within the body, comprising:

• an elongated member having a proximal portion, a distal portion, and at least one lumen therein in fluid communication with a cooling fluid;
• a plurality of ablation tips coupled to the distal portion of said elongated member configured to contact and ablate tissue, said plurality of ablation tips configured to form a line of conduction block at said target site;
• and
• means for controlling the transmural depth of said plurality of ablation tips into the tissue.

A medical device for inducing controlled necrosis at a target site within the body, comprising:

• an elongated member having a proximal portion, a distal portion, and at least one lumen therein in fluid communication with a cooling fluid;
• at least one retractable ablation tip coupled to the distal portion of said elongated member, said at least one retractable ablation tip being configured to contact and ablate tissue;
• and
• at least one control wire configured to retract said at least one retractable ablation tip within said tissue.

A cryosurgical method for inducing controlled necrosis at a target site within the heart, comprising the steps of:

• providing a cryotreatment device having a proximal portion, a distal portion, and at least one lumen therein in fluid communication with a cryogenic fluid, the distal portion of said cryotreatment device including at least one ablation tip configured to contact and ablate tissue;
• advancing the cryotreatment device to the target site and inserting said at least one ablation tip into the tissue;
• controlling the transmural depth of said at least one ablation tip into the tissue;
• and
• injecting the cryogenic fluid through said at least one lumen to the distal portion of the cryotreatment device.

A cryosurgical method for inducing controlled necrosis at a target site within the heart, comprising the steps of:

• providing a cryotreatment device having a proximal portion, a distal portion, and at least one lumen therein in fluid communication with a cryogenic fluid, the distal portion of said cryotreatment device including a plurality of linearly-disposed ablation tips configured to contact and ablate tissue;
• advancing the cryotreatment device to the target site;
• inserting said plurality of ablation tips into the tissue;
• controlling the transmural depth of said plurality of ablation tips into the tissue;
• and
• injecting the cryogenic fluid through said at least one lumen to the distal portion of the cryotreatment device to form a line of conduction block at the target site.

A cryosurgical method for inducing controlled necrosis at a target site within the heart, comprising the steps of:

• providing a cryotreatment device having a proximal portion, a distal portion, and at least one lumen therein in fluid communication with a cryogenic fluid, the distal portion of said cryotreatment device including a plurality of radially-disposed ablation tips configured to contact and ablate tissue;
• advancing the cryotreatment device to the target site;
• inserting said plurality of ablation tips into the tissue;
• controlling the transmural depth of said plurality of ablation tips into the tissue;
• and
• injecting the cryogenic fluid through said at least one lumen to the distal portion of the cryotreatment device to form a circumferential line of conduction block at the target site.

A cryosurgical method for inducing controlled necrosis at a target site within the heart, comprising the steps of:

• providing a cryotreatment device having a proximal portion, a distal portion, and at least one lumen therein in fluid communication with a cryogenic fluid, the distal portion of said cryotreatment device including a plurality of ablation tips configured to contact and ablate tissue;
• advancing the cryotreatment device along a guiding member to the target site and inserting said plurality of ablation tips into the tissue;
• providing an ultrasonic probe at or near the target site proximal said plurality of ablation tips and acoustically measuring the penetration depth of said plurality of ablation tips into the tissue;
• and
• injecting the cryogenic fluid through said at least one lumen to the distal portion of the cryotreatment device, thereby forming a conduction block within the target site blocking electrical signals to one or more relay points within the heart.