Cryoplasty for peripheral vascular disease

Background In the UK, symptomatic peripheral arterial disease ( PAD) occurs in 5 to 7% of people over the age of 55 years. Cryoplasty offers a new approach by combining the dilation force of balloon angioplasty with the delivery of cold thermal energy to the vessel wall. Cryoplasty is thought to provoke apoptosis rather than necrosis in the arterial smooth muscle cells and thus has the theoretical advantage of reduced myointimal hyperplasia in long-term patency. As it is an emerging therapy, safety and efficacy questions remain. This systematic review evaluates the treatment and provide focus for further research in the field. Objectives To assess the efficacy of, and complications associated with, cryoplasty for maintaining patency in the iliac or infrainguinal arteries. Search strategy We searched the Specialized Register of the Cochrane Peripheral Vascular Diseases Group ( inception to August 2007), the Cochrane Central Register of Controlled Trials ( CENTRAL) in The Cochrane Library 2007, Issue 3, along with MEDLINE ( 1966 to August 2007) and EMBASE ( 1980 to August 2007). Selection criteria Trials in which patients with peripheral arterial disease ( PAD) of the iliac or infrainguinal arteries were randomised to cryoplasty with or without another procedure versus a procedure without cryoplasty. This includes trials where all patients receive angioplasty and the randomisation is for cryoplasty versus none. Data collection and analysis Studies identified for potential inclusion were independently assessed for inclusion by at least two authors, with excluded trials arbitrated by the third author. As no randomised controlled trials of cryoplasty were found, no statistical analyses were performed. Main results No randomised controlled trials of cryoplasty were identified. Authors'conclusions The benefit of cryoplasty over conventional angioplasty has not been established as no randomised controlled trials exist to properly evaluate this method. Technical success and primary patency rates seen in the prospective series are encouraging and may suggest a future role for cryoplasty in the treatment of PAD, but cannot be reliably interpreted due to the nature of the studies.