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.