Drug-Eluting PAD Stent Approved

Zilver PTX Drug Eluting Peripheral Stent gets FDA nod

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) US Food and Drug Administration officials have approved the first medication-coated stent designed to treat peripheral artery disease (PAD), giving patients with blocked thigh arteries another option.

PAD patients experience blocked leg arteries causing symptoms such as leg pain or serious complications that could result in leg amputation.

The FDA approved Cook Incorporated's Zilver PTX Drug-Eluting Peripheral Stent. It is a small, metal mesh tube that self expands to keep open the blocked artery. The stent is coated with drug paclitaxel to help prevent another blockage.

"Discuss PAD treatment options with your cardiologist."

Christy Foreman, director of the Office of Device Evaluation at FDA’s Center for Devices and Radiological Health, said the clinical study that helped green light the device showed that Zilver is more effective than standard balloon angioplasty for treating blockages in the thigh as a result of PAD.

“This approval expands the treatment options for patients suffering from symptomatic peripheral artery disease to include the Cook Zilver PTX drug eluting stent,” she said.

The device was approved to re-open the femoropopliteal artery, an artery in the thigh.

Prior to approval of the drug-eluting stent, other treatment options included bare metal stents, balloon angioplasty, surgical bypass surgery similar to the same procedure performed on the heart, exercise and medication.

Zilver was approved following animal testing and clinical trials. During one trial, researchers followed 479 PAD patients with a single thigh blockage. Participants randomly received either the Zilver stent or underwent percutaneous transluminal intervention (PTI), a surgical procedure in which a catheter with a balloon tip is used to open the blocked artery. If PTI failed, the patient received either a Zilver stent or a bare metal stent.

After 12 months, 83 percent of the blockages opened with the Zilver stent were still open compared to 33 percent of narrowings treated with PTI. Among unsuccessful PTI patients, 90 percent of arteries treated with the Zilver stent remained open compared to 73 percent of those treated with bare metal stents.

In another study, 787 PAD patients received up  to four Zilver stents to open one or more clogs. Researchers concluded the Zilver stents were at least as safe as PTI.

Investigators noted that 1.5 percent of patients experienced a stent fracture that was not problematic. At 12 months, 2.8 percent of patients had experienced stent thrombosis, and 3.5 percent experienced it by 24 months. Stent thrombosis is a rare, but serious condition in which a blood clot forms on a stent's surface.

In both studies the most common complication was that patients required additional treatment to re-open the blocked artery.

As part of the approval, Indiana-based Cook Incorporated must complete a 5-year study of 900 patients treated with the Zilver stent to further monitor safety and effectiveness.

The device is not appropriate for women who are pregnant, breastfeeding or who plan to become pregnant. In addition, the stent should not be used in patients whose arteries are narrowed to the point that the device cannot safely pass to allow stent placement, or in those who can't take the recommended therapy because of bleeding disorders.

Reviewed by: 
Review Date: 
November 20, 2012
Last Updated:
November 21, 2012