Boston Scientific (Natick, Massachusetts) said FDA has approved the Express SD Renal Monorail pre-mounted stent system for use as an adjunct to percutaneous transluminal renal angioplasty (PTRA) in certain lesions of the renal arteries.
According to the company, the Express SD system is the first low-profile, pre-mounted stent approved for use in renal arteries in the U.S. It also is the only FDA-approved renal stent designed to provide additional proximal end support, the company said.
Nate Harrington, a marketing manager at Boston Scientific, told Medical Device Daily that the company expects the Express SD system to be the only such device with a renal indication for at least a couple of years. He said the stent system would be commercially available in the U.S. immediately.
Based on the company's Maverick Monorail balloon catheter technology and Tandem Architecture stent design, the Express SD renal stent is designed to provide strength, precision and deliverability, according to Boston Sci.
The type of stent system, balloon-expandable, is fairly standard, Harrington said, but its design sets it apart from competing devices.
"The stent design, the proximal part of the stent has reinforced scaffolding, which is designed for ostial renal lesions," Harrington said. "So it is actually a differentiated design for a balloon-expandable stent."
The additional support at the end of the device is especially important in lesions occurring at the opening of the renal artery (ostial lesions), Harrington said.
"FDA approval for the Express SD renal stent is an important step in providing physicians evidence-based technology to facilitate the management of renal artery disease," said Jim Tobin, president/CEO of Boston Scientific. "With the addition of the Express SD renal stent, Boston Scientific can now offer customers the industry's leading portfolio of products for endovascular treatment of this disease."
Renal artery disease is the narrowing of the main blood supply to the kidneys due to atherosclerosis, or the formation of plaque within the arteries, which can lead to high blood pressure or poor kidney function. The disease can be treated surgically, with medication, or less invasively with angioplasty. Re-narrowing of the arteries can occur after angioplasty, and the use of stenting as an adjunctive treatment option is intended to assist in their re-opening, Boston Scientific noted.
Two-year results from the RENAISSANCE clinical trial, which was designed to evaluate the safety and efficacy of the Express SD renal stent in hypertensive patients with atherosclerotic renal artery stenosis, demonstrated a statistically significant improvement in systolic blood pressure and no statistical difference in either diastolic blood pressure or serum creatinine levels from baseline through three years. Nine-month results demonstrated a binary restenosis rate of 21.3% (23/108), low target lesion revascularization rates of 8.1% (9/111) and no stent thrombosis (0/100), the company said.
"The approval of the Express SD stent for renal indications provides physicians with an on-label stenting option for use with PTRA in certain patients with renal artery disease," said Krishna Rocha-Singh, MD, of Prairie Cardiovascular Heart Institute (Springfield, Illinois), principal investigator of the RENAISSANCE trial.
Harrington attributed the FDA approval of the Express SD renal stent to the company's investment in the RENAISSANCE trial. He also noted the importance of bringing on on-label device for this application to market. "The environment we're in today where both physicians and industry are under additional scrutiny by regulatory authorities it's ever more important for companies, physicians and for hospitals to have on-label devices."