Method and device for performing cooling or cryo-therapies, for, e.g., angioplasty with reduced restenosis or pulmonary vein cell necrosis to inhibit atrial fibrillation employing tissue protection
View Patent ↗An enhanced method and device are provided to treat atrial fibrillation or inhibit or reduce restenosis following angioplasty or stent placement. A balloon-tipped catheter is disposed in the area treated or opened through balloon angioplasty immediately following angioplasty. The balloon, which can have a dual balloon structure, may be delivered through a guiding catheter and over a guidewire already in place. A fluid such as a perfluorocarbon flows into the balloon to freeze the tissue adjacent the balloon, this cooling being associated with reduction of restenosis. A similar catheter may be used to reduce atrial fibrillation by inserting and inflating the balloon such that an exterior surface of the balloon contacts at least a partial circumference of the portion of the pulmonary vein adjacent the left atrium. In another embodiment, blood perfusion is performed simultaneously. In another embodiment, tissue contacted by the cryoablation catheter, undesired to be ablated, is protected against damage by a separate heating step.
1. A device to treat tissue while preventing tissue damage to adjacent tissue, comprising:
an ablation catheter;
wherein the ablation catheter further defines:
a guidewire lumen;
a supply lumen; and
a return lumen,
an introducer sheath for the ablation catheter, wherein, in use, the device is adapted to be positioned such that the ablation catheter contacts tissue to be treated and the introducer sheath contacts tissue to be protected;
a heater disposed adjacent or within the introducer sheath, the heater adapted to be thermally coupled to the tissue;
a control unit for the heater; and
a source of cryofluid having a supply tube and a return tube, the supply tube coupled in fluid communication to the supply lumen and the return tube coupled in fluid communication to the return lumen, wherein the cryofluid has been substantially purged of dissolved gases.
2. The device of claim 1 , wherein the heater is a resistive heater.
3. The device of claim 1 , wherein the heater includes an inlet tube fluidically coupled to an interior of the introducer, and at least one outlet orifice disposed in the introducer.
4. The device of claim 1 , wherein the heater includes an inlet sleeve with an input for a body fluid at a distal end of the introducer sheath, wherein the inlet sleeve is fluidically coupled to an interior of the introducer, and at least one outlet orifice disposed in the introducer.
5. The device of claim 4 , wherein the inlet sleeve has an annular shape along a portion thereof.
6. The device of claim 2 , wherein the resistive heater is disposed on a sleeve, the sleeve concentric with the introducer sheath.
7. The device of claim 6 , wherein the resistive heater is helically wound on the sleeve.
8. The device of claim 2 , wherein the guidewire lumen extends from a proximal end of the ablation catheter to a distal end of the ablation catheter.
9. The device of claim 1 , further comprising at least one marker band disposed on the ablation catheter to locate a working region of the device at a desired location.
10. The device of claim 1 , wherein the cryofluid is a perfluorocarbon.
11. The device of claim 10 , wherein the cryofluid is Galden® fluid.
12. The device of claim 1 , wherein the cryofluid is DMSO.
13. The device of claim 1 , wherein the cryofluid is D-limonene.
14. The device of claim 1 , further comprising a gear pump for circulating the cryofluid.
15. The device of claim 14 , wherein the gear pump is one selected from the group consisting of a radial spur gear pump and a helical tooth gear pump.