Nine-month clinical endpoint data from the ORION trial demonstrate excellent outcomes for the Epic self-expanding nitinol stent system (Boston Scientific) in patients with iliac artery disease. Results were presented by Daniel Clair, principal investigator of the trial and chairman of the Department of Vascular Surgery, The Cleveland Clinic Foundation, at the 24th International Symposium on Endovascular Therapy (ISET) in Miami, USA.
“Peripheral stenting has become a recognised standard in the treatment of iliac arterial disease to restore blood flow in blocked leg arteries,” said Clair. “Outcomes from the ORION trial support both the safety and efficacy of the Epic stent and confirm its excellent performance in the treatment of atherosclerotic lesions in iliac arteries.”
The prospective, single-arm ORION trial enrolled 125 patients at 28 sites in the USA. The trial met its primary endpoint, a composite rate of device- and/or procedure-related major adverse events (MAE) at nine months. MAE are defined as death within 30 days, myocardial infarction occurring during hospitalisation, target vessel revascularisation (TVR) through nine months and amputation of the treated limb through nine months.
The Epic stent demonstrated a low nine-month MAE rate of 3.4% in the intent-to-treat population, which was significantly lower than the pre-specified performance goal of 17% (p<0.001) based on historical published outcomes for iliac stenting. All reported major adverse events were related to target vessel revascularisation. No deaths through 30 days and no amputations through nine months were observed.
Patients experienced significant clinical improvement from baseline to nine months based on feedback from validated questionnaires evaluating walking distance, speed and stair climbing. An additional measure of effectiveness based on the Rutherford Classification showed improvement in the patient population from 7.2% being asymptomatic or having mild claudication (class 0-1) at baseline to 82.3% of patients at 30 days and 81.6% at nine months.
Duplex ultrasound showed a primary patency of 95.9%, primary-assisted patency of 96.7% and secondary patency of 98.3%, indicating that treated lesions remained open through the nine-month follow-up period.
The Epic stent is a self-expanding nitinol stent designed to sustain vessel patency, while providing enhanced visibility and accuracy during placement. It employs an innovative Tandem Architecture, which is engineered to provide excellent stent flexibility while maintaining predictable radial force characteristics across the entire stent size matrix. The stent is compatible with 6F sheaths, and the stent delivery system is compatible with 0.035 inch guidewires.
ORION clinical data is being used to support application for US Food and Drug Administration (FDA) approval of the Epic stent system, which was submitted to the FDA in September 2011.
The Epic nitinol stent system received CE mark approval and was launched in Europe and other international markets in 2009.