Linear ablation devices and methods of use
Described herein are various methods and devices for delivering cryoablative therapy. Various ablative patterns can be produced by the devices, including, linear ablation patterns. One exemplary device includes a cryoablation chamber and a volume displacement chamber. In use, the volume displacement chamber can be expanded to support the cryoablation chamber.
1. A cryotherapy device comprising:
an elongate catheter shaft extending between a proximal and distal end; and
an expandable body comprising at least first and second cambers, the chambers positioned proximate to the distal end of the catheter shaft, the first chamber in fluid communication with a lumen for transmitting cryofluid to the first chamber, the first chamber having an elongate shape for creating a linear ablation pattern, the second chamber positioned adjacent to the first chamber,
wherein the first chamber is positioned to deliver cryotherapy and form a linear ablation pattern when filled with cryofluid and wherein the second chamber is configured to support the first chamber.
2. The device of claim 1 , wherein the second chamber has a size and shape, when expanded, that substantially corresponds to an anatomic structure.
3. The device of claim 1 , wherein the second chamber is sized and shaped to occupy a cardiac chamber when expanded.
4. The device of claim 3 , wherein the second chamber is configured to hold the first chamber in contact with tissue when expanded.
5. The device of claim 1 , further comprising a source of cryofluid that is in fluid communication with the first chamber.
6. The device of claim 1 , wherein the first chamber has a linear shape when expanded.
7. The device of claim 1 , wherein the first chamber occupies less than about 50 percent of the surface area of the second chamber.
8. The device of claim 1 , wherein the first chamber occupies less than about 30 percent of the surface area of the second chamber.
9. The device of claim 1 , wherein the first chamber has a circular shape.
10. The device of claim 1 , wherein the first chamber encircles, but does not enclose the second chamber.
11. The device of claim 1 , wherein the first chamber encircles a non-ablating portion of the expandable body.
12. The device of claim 1 , wherein the first chamber is adapted to form a lesion around at least a portion of a pulmonary vein.
13. The device of claim 1 , further comprising an additional chamber for receiving cryofluid.
14. The device of claim 1 , further comprising at least one radio opaque marker mated with the second chamber.
15. The device of claim 1 , further comprising sensors for sensing cardiac signals.
16. The device of claim 1 , wherein a first and second sensor are positioned on opposing sides of the first chamber for testing the ability of adjacent tissue to transmit electrical signals.
17. A cryotherapy device with stand-alone ablation chamber comprising:
an elongate catheter shaft having a proximal and distal end;
an expandable first chamber positioned proximate to the distal end of the catheter shaft, the first chamber in fluid communication with a lumen for transmitting cryofluid to the first chamber; and
a source of cryofluid that is in fluid communication with the first chamber,
wherein delivery of cryofluid to the first chamber cause the first chamber to move from a first, low profile delivery configuration to an expanded configuration such the first chamber is positioned for producing a linear ablation pattern.
18. The device of claim 17 , further comprising a stiffening mechanism for supporting the first chamber.
19. The device of claim 18 , wherein the catheter shaft includes a lumen for housing a stiffening rod.
20. The device of claim 17 , wherein, when expanded, the first chamber defines an open interior region that is not in fluid communication with a source of fluid.
21. The device of claim 17 , wherein at least a portion of the first chamber has a size and shape adapted to produce a linear ablation pattern when cryofluid is delivered into the first chamber.