Standardized evaluation and reporting of stent fractures in clinical trials of noncoronary devices

Objectives: Define the prospective surveillance and reporting parameters for assessment of metallic stents used in clinical trials of superficial femoral artery atherosclerosis. Background: While advances in medical therapies to improve atherosclerotic risk factor profiles in patients with peripheral arterial disease have focused on prevention of disease progression, the development of endovascular devices is altering the therapeutic algorithm for patients with peripheral arterial disease. Stents have emerged as one of the advances that may promote durable patency, particularly in the infrainguinal arteries. Methods: The Zilver-PTX is a prospective multicenter randomized trial of bare metal versus drug-eluting nitinol stents for superficial femoral artery peripheral arterial disease. A predefined surveillance program is mandated in this trial. During the genesis of this program, it became clear that no single standard has existed to identify, classify, and report fractures of metallic stents placed in peripheral arteries. Results: This report defines the key components of prospective stent fracture surveillance, including location of radiographic images obtained, types of radiographic equipment, methods of limb, and image intensifier positioning, intervals required for imaging, grading schemes for reporting, and methods of analyzing the images. Conclusions: As the proliferation of minimally invasive revascularization strategies continues, the stability of metallic endoprostheses is increasingly critical. Uniform surveillance of these devices for fracture and disarticulation is important in order to compare the relative merits of various stent-based devices in clinical trials.