|dc.description.abstract||In 2007 it was reported that eight million Americans are affected by Peripheral Vascular Disease (PVD) and of these affected, around ten percent report being symptomatic (Mayo Clinic). With such a large percentage of Americans affected by this problem, many providers who care for these patients opt to treat with the least invasive option and then progress to more invasive means if necessary. To date, Percutaneous Transluminal Angioplasty (PTA) has been the preferred minimally invasive endovascular treatment option for symptomatic PVD. Though this option is preferred and used extensively, there are concerning short and long term potential consequence such as dissection and recoil of the arterial wall in the acute setting (Laird 2005), and, more importantly, re-stenosis of the affected area in the long term setting causing recurrent symptoms and the need for further treatment. There have been multiple reported results showing that the re-stenosis rates have been as high as 60% (Muradin 2001). Additionally, the Oxford trail showed that the quality of life in the long term setting was not improved and thus required additional therapy (Perkins 1996).
Studies examining PTA procedures have shown that restenosis is caused by three processes: immediate elastic recoil, late vascular remodeling, and importantly myointimal hyperplasia (McCaslin 2007). Myo-intimal hyperplasia results from the balloon dilation of the vessel wall causing proliferation of the vascular smooth muscle cells in the intimal layer of the vessel. This proliferation results in increased mass of smooth muscle and thus a restriction of blood flow through the affected lumen.
Due to the need for patency in the long term and the myointimal hyperplasia response of angioplasty, a technique building off of angioplasty called Cryoplasty is now offered. This method adds the dilation properties of angioplasty with an associated release of cold thermal energy to the arterial wall. The cold thermal energy is derived from the filling catheter containing nitrous oxide instead of the standard contrast and saline solution. The affect of this cooling process is thought to limit the variables such as myo-intimal hyperplasia and elastic recoil in the process of re-stenosis (Samson 2007). The success rate of cryoplasty has been promising with one study showing a 3-year patency rate of 75% (Laird 2006).||en_US