Cryoplasty apparatus and method

A system for angioplastic treatment of arterial stenosis and for reducing restenosis, comprising:

• a) An angioplasty balloon catheter useable to treat arterial stenosis, having a gas input lumen for supplying a preasurized gas, a first inflatable balloon containing a first variable volume, and a Joule-Thomson orifice for passing said pressurized gas from said gas input lumen into said first variable volume of said first inflatable balloon so as to cool and inflate said first inflatable balloon;
• b) a supply of compressed cooling gas operable to supply cooling gas to said gas input lumen;
• c) a cooling gas input valve controlling delivery of compressed cooling gas from said supply of compressed cooling gas to said gas input lumen;
• and
• d) a plurality of thermal sensors operable to report external temperatures along a selected length of said catheter, thereby enabling said catheter to report a temperature gradient along a selected segment of a body conduit when said catheter is inserted into said body conduit, said plurality of thermal sensors being distributed along an expandable spiral sensing loop having a distal end anchored to a distal portion of said catheter, said sensing loop being spirally wound around a section of shaft of said catheter and being operable to expand away from said shaft, thereby enhancing thermal communication between said sensors distributed along said sensing loop and body tissues adjacent to said catheter.