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NEW ORLEANS -- Drug-eluting stents provide good outcomes for patients with critical limb ischemia in whom balloon angioplasty has failed, a single-center study showed.

During an average follow-up of 25 months, 89.3% of the patients remained free from amputation and 22.4% died, a mortality rate consistent with previous studies of endovascular treatment of critical limb ischemia, according to Robert Lookstein, MD, of Mount Sinai Medical Center in New York City.

"Drug-eluting stents can decrease re-intervention rates and amputation rates in a very, very high-risk patient population," Lookstein said at a press conference at the Society of Interventional Radiology meeting. "Patients should be aware that there are highly successful, minimally invasive options performed by interventional radiologists that are available now to relieve their symptoms of critical limb ischemia and help them avoid major amputation."

The benefits of drug-eluting stents appear to be greatest among patients with the earlier forms of the disease, without gangrene and with only small ulcers and very little tissue loss, Lookstein said, noting that the amputation-free rate was 100% after excluding the patients with the most severe disease.

That result is arguably "superior to historic results for bypass surgery and is definitely superior to the angioplasty results in the literature," he said.

Critical limb ischemia is a more severe form of peripheral arterial disease, and the associated amputation rate has increased in recent decades, driven by a rising rate of diabetes and the aging of the population. Prognosis is poor for affected patients, with amputation and mortality rates of 25% within the first year. Of those who have a below-knee amputation, half will not survive past 5 years.

The gold standard treatment for critical limb ischemia is bypass surgery to restore blood flow to the affected limb, but many patients cannot undergo the operation because of comorbidities or an inadequate vein with which to perform the bypass.

Endovascular therapy is another option. It has primarily involved balloon angioplasty but drug-eluting stents -- the same ones used in coronary arterial circulation -- are now being used. The vessels in the infrapopliteal circulation in the leg are similar in size to those in coronary arterial circulation, Lookstein noted.

He and his colleagues evaluated outcomes in 107 patients with critical limb ischemia who received drug-eluting stents at their center over a 7-year period after failing angioplasty in the infrapopliteal arteries. The mean age of the patients was 82.

One-third of the patients had Rutherford category 4 disease (ischemic pain at rest), half had category 5 disease (minor tissue loss), and 18% had category 6 disease (ulceration or gangrene). Roughly one-third (35%) had total occlusions in the infrapopliteal circulation.

Comorbidities were common -- 66% of the patients had coronary artery disease, 73% had diabetes, and 64% had chronic renal disease.

During the procedure, a total of 171 drug-eluting stents were used -- 106 with sirolimus, 62 with everolimus, and 3 with paclitaxel -- for an average of 1.6 per patient. The stented diameters ranged from 2.5 to 4 mm.

Most of the patients (69%) underwent a femoral-popliteal intervention at the same time.

The stent was successfully delivered to the site of the failed angioplasty in 100% of the cases. Primary patency was maintained in 90% of the patients at 6 months, 84% at 12 months, and 72% at 24 months.

Only one patient died within the first 30 days.

Although the results are good, Lookstein said, it remains unclear whether using drug-eluting stents as first-line therapy would improve clinical outcomes. No U.S. trials have examined the question, and numerous trials in Europe have shown a benefit in terms of patency and freedom from target lesion revascularization at 1 year, but no significant effect on limb salvage or overall survival.

From the American Heart Association:

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