Post-angioplasty hyperplasia in blood vessels is treated using a
cryosurgical balloon catheter. The balloon catheter is positioned at a target region
within the blood vessel, and the balloon inflated by expanding a cryogenic fluid,
such as liquid nitrogen, across an expansion orifice into a balloon. The balloon
will be constructed so that cooling is achieved primarily in the central regions
of the balloon, with the proximal and distal regions being less cold and acting
to insulate adjacent regions of the blood vessel from excessive cooling.
