Covidien (NYSE:COV) said it closed enrollment in a pair of its Visibility and Durability iliac stent clinical studies.

The prospective, multinational studies are designed to compare balloon stents with self-expanding stents in the iliac arteries for treating peripheral artery disease.

Half of the 150 patients will be treated with the balloon stent and the 2nd cohort with the self-expanding stents at 23 medical centers in the U.S. and Europe. Patients will be evaluated for 9 months, with a 3-year follow-up.

"We are very pleased to report the completion of enrollment in these 2 studies, as the results will add important clinical data around treatment of patients with PAD," CMO Dr. Mark Turco said in a statement.

Last month, Covidien battled bad press surrounding a "failed" clot-removing device study and launched a massive randomized controlled trial for acute ischemic stroke patients.