The invention provides techniques and devices for treating atherosclerotic disease using controlled cryogenic cooling, often in combination with angioplusty. The efficacy of endolusninal cryogenic cooling is enhanced by cooling of target tissues using an insulated cryogenic balloon, the lnsulation ideally comprising a fluid which undergoes a phase change at a predetermined temperature. A combination cryogenic/angioplasty catheter avoids exchange procedures between dilation of a stenotic region within a vessel wall and the application of cryogenic cooling. The combination angioplasty/cryogenic cooling catheter may cool the diseased blood vessel before, during, and/or after dilation. Controlled cooling of the vessel wall may change its mechanical properties, weakening the vessel and allowing it to be expanded at a much lower pressure than with conventional uncooled angioplasty. Similar reductions in restenosis may be provided for other primary treatments of the blood vessel, including directional arthrectomy, rotational arthrectomy, laser angioplasty, stenting, and the like.