Peripheral arterial disease results from narrowing of the main arteries to the legs because of atherosclerosis, which limits the supply of nutrients to the muscles and other tissues. The shortage of blood flow caused by a blocked artery can become so severe that a limb is threatened (critical limb ischaemia) and surgery is required. Endovascular surgery involves inserting a small balloon into the affected artery. The balloon is inflated to break up the atheromatous plaque, stretch the smooth muscle cells within the middle of the vessel wall and widen the arterial lumen (called percutaneous balloon angioplasty). Unfortunately the artery often narrows again over time (restenosis). Cryoplasty applies cold to the vessel wall at the same time as using the dilation force of balloon angioplasty and may reduce thickening of the inner muscular layer of the blood vessel to improve long-term angioplasty results.
The benefit of cryoplasty over conventional angioplasty has not been established as no randomised controlled trials exist to properly evaluate this new method. The technical success and rates of unobstructed arteries (primary patency) seen in six case series are encouraging and suggest a future role for cryoplasty in the treatment of peripheral arterial disease. The long-term outcomes are as yet unknown.