Object: Carotid artery (CA) angioplasty with stent placement has been proposed as an alternative technique for revascularization in cases of CA stenosis. In this report the authors review the results of a multicenter Phase I study in which they evaluated the safety and feasibility of using a new self-expanding nitinol stent, the Bard Memotherm, to treat CA stenosis.
Methods: Enrollment was limited to patients in whom there was either 50% or greater symptomatic or 70% or greater asymptomatic stenosis of the internal CA. The primary endpoint was a technically successful implantation procedure (delivery of the stent to the target site and retrieval of the delivery device), resulting in less than 30% residual stenosis demonstrated on immediate postprocedure (control) angiograms, and no incidence of mortality, ipsilateral stroke, Q-wave myocardial infarction, or other major cardiovascular events immediately after or within 30 days following the procedure. Stent placement was attempted for 73 lesions in 71 patients (mean age 71.3 +/- 8.5 years), 43 (61%) of whom were men. The mean degree of stenosis was 82.6 +/- 9%. The stenosis was symptomatic in 27 (37%) and asymptomatic in 46 (63%) of 73 lesions. In four procedures the stent could not be delivered or released. The mean residual stenosis observed on angiograms was 3.8 +/- 6.9% in the 69 lesions treated with the Bard Memotherm stent; residual stenosis was greater than 30% in one of the 69 procedures. The primary endpoint was achieved in 65 (89%) of the 73 procedures. One patient experienced a major ischemic stroke and another patient died of intracerebral hemorrhage. The overall 1-month stroke rate was 2.7% for 73 attempted procedures. One patient died of pneumonia and acute respiratory distress syndrome, which occurred 3 weeks after the stent procedure and was unrelated to the procedure.
Conclusions: The Memotherm stent can be used to treat patients with CA stenosis and is associated with a low peri-procedure complication rate. Long-term follow-up studies are underway to determine the impact of stent placement on the risk of ipsilateral ischemic events.