Cryotherapy methods for treating vessel dissections and side branch occlusion
The present invention provides cryotherapy treatment of dissections in a blood vessel of a patient. The present invention further provides cryotherapy treatment of side branch occlusion in a bifurcated blood vessel. One method for treating potential or existing dissections in a blood vessel comprises cooling the blood vessel to a temperature and for a time sufficient to remodel the blood vessel such that dissections of the blood vessel are reduced. Another method for treating side branch occlusion in a bifurcated blood vessel, the bifurcated blood vessel having a side branch and a main branch, the main branch having plaque disposed thereon, comprises cooling an inner surface of the main branch to a temperature and for a time sufficient to inhibit plaque shift from the main branch into the side branch.
1. A method for treating side branch occlusion in a bifurcated blood vessel, the bifurcated blood vessel having a side branch and a main branch, the main branch having plaque disposed thereon, said method comprising:
cooling an inner surface of the main branch to a temperature and for a time sufficient to inhibit plaque shift from the main branch into the side branch
wherein the cooling time is in a range from about 1 second to less than 20 seconds, and wherein the cooling temperature of the inner surface of the main branch is in a range from about −3° C. to about −15° C.
2. A method as in claim 1 , wherein the main branch is an artery.
3. A method as in claim 1 , wherein the plaque comprises a combination of calcium, fat, and lipids.
4. A method as in claim 1 , wherein the side branch is subject to occlusion by plaque shift from the main branch into the side branch as a result of treatment of plaque in the main branch.
5. A method as in claim 4 , wherein the treatment of plaque in the main branch comprises balloon angioplasty.
6. A method as in claim 5 , wherein the cooling step is performed before, during, and/or after balloon angioplasty.
7. A method as in claim 6 , wherein the side branch is at least partially stenosed.
8. A method as in claim 7 , wherein the treatment of stenosis in the side branch comprises balloon angioplasty.
9. A method as in claim 8 , wherein the main branch and side branch are treated simultaneously or sequentially.
10. A method as in claim 1 , wherein the cooling step alters mechanical properties of the plaque so that plaque shift from the main branch to the side branch is inhibited.
11. A method as in claim 10 , wherein the cooling step solidifies the plaque so that it is less amorphous.
12. A method as in claim 11 , wherein plaque solidification is enhanced by the formation of a temporary ice cap on an orifice of the side branch.
13. A method for treating side branch occlusion in a bifurcated blood vessel, the bifurcated blood vessel having a side branch and a main branch, the main branch having plaque disposed thereon, said method comprising:
introducing a catheter into a lumen of the main branch;
positioning a balloon within the main branch lumen adjacent the plaque;
introducing a cryogenic cooling fluid into the balloon;
exhausting the cooling fluid;
expanding the balloon to radially engage the main branch lumen; and
cooling an inner surface of the main branch to a temperature and for a time sufficient to inhibit plaque shift from the main branch into the side branch
wherein the cooling time is in a range from about 1 second to less than 20 seconds, and wherein the cooling temperature of the inner surface of the main branch is in a range from about −3° C. to about −15° C.