Medical Device Daily

Despite evidence indicating that carotid artery endarterectomy (CAE), the surgical approach to the problem of symptomatic carotid stenosis, is either better than carotid artery stenting (CAS), or that the two approaches are generally equivalent, large numbers of stents continue to be inserted into asymptomatic patients with carotid stenosis, according to a presenter at the recent VEITHsymposium in New York.

Peter Bell, MD, former president of the International Society for Vascular Surgery (Smithtown, New York) and currently with the Royal Infirmary Hospital (Leicester, UK), told Medical Device Daily during the symposium that carotid stents "are being over-utilized to an enormous degree, even though it is accepted that they should only be used in trials or when the patient is at a high risk from surgery."

Bell said that for those with stenosis of the carotid arteries but no symptoms, the risk of stroke is "very small" but that the tendency in the UK is to perform CAS for all cases, a tendency that he argued "is being pushed by industry."

"There is no question that some operators can insert stents into carotid arteries without causing serious problems, but the fact is that the majority of those using them cause more problems than are caused by endarterectomy or using only medical treatment," Bell told MDD. "For those who can safely perform carotid angioplasty and stenting with low rates of complications, then they are ethically able to use this technique, even though there is no proof that it is any better than an endarterectomy or equivalent to it. For those who are not able to obtain good results, then their activity is, at best, unethical."

Trials have shown there is an advantage to treating a patient with surgery, but physicians can't always tell which patients are going to have a stroke.

One of those studies, Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE), revealed similar stroke rates among patients treated with either technique: 7.1% in those who received stents and 6.7% in endarterectomy patients (945 patients in all).

But Bell argues that anything beyond a 3% complication rate is considered unacceptable.

"We know from previous studies that if you have a complication rate of more than 3%, you're causing problems," he said.

Bell noted an ongoing turf war between surgeons and interventionalists.

"If a patient has no symptoms and a greater than 80% narrowing on one side, I would advise him to get medical treatment, stop smoking, control blood pressure and give him a dose of statins," he said, rather than either CAE or CAS.

A duplex scan can be done on an annual basis to see if the narrowing is hard or soft. Non-invasive duplex scanning may be the key to determine just how dangerous a narrowed passage can be. Softer stenoses are apparently more dangerous than hard stenoses.

"If a patient has one side blocked up entirely and the other side narrowed by 80%, that's a bad situation and I would do enterectomy," Bell said. "I would only use stents in patients who have no other options. It is accepted practice and quite clear that you're not supposed to be using stents unless there are no other options — or as part of a trial."

Bell said the answer to this ongoing dilemma would be a much larger trial to better define the proper approach.

John Rundback, MD, of Columbia University College of Physicians and Surgeons, and director of the Interventional Institute, Holy Name Hospital (Teaneck, New Jersey), presented an update on studies which are intended to overcome this dilemma.

In asymptomatic patients — nearly three-quarters of those with extracranial internal CAS — there are currently two trials comparing stenting with CAE. However, neither trial is evaluating targeted medical therapy with defined risk-management reduction strategies, something Bell said must be included for a definitive answer.

A third multinational randomized trial, Transatlantic Asymptomatic Carotid Intervention Trial (TACIT), will compare optimal medical therapy (OMT) alone, OMT with stenting, and OMT and CEA in asymptomatic patients. However, TACIT has yet to get underway due to a lack of funding, Bell said.

Rundback said that TACIT "represents a landmark opportunity to critically evaluate the key remaining questions regarding the best care for patients with asymptomatic carotid artery stenosis. In addition to ascertaining procedural risk and stroke rates related to medical therapy with and without revascularization, TACIT will explore pivotal endpoints including neuron-cognitive function, the impact of ultrasound plaque characterization with GSM analysis on clinical outcomes, and detailed cost effectiveness and quality-of-life domains."

In other news from the symposium:

• Postoperative paraplegia and paraparesis have been the scourge of thoracoabdominal aortic aneurysm (TAAA) repair since the inception of the procedure. Open repair is difficult and dangerous, with mortality rates of roughly 20% at one month and 30% at one year. Endovascular repair using a hybrid debranching technique has also resulted in disappointing mortality and morbidity rates. Timothy Chuter, MD, of the University of California (San Francisco), presented evidence on multi-branched stent graft implantation, an option that may offer a less-invasive and safer approach to TAAA repair.

Most published reports lack long-term data to draw definitive conclusions regarding the durability of multi-branched stent grafts. However, promising short-term results indicate that the multi-branched stent graft will inevitably become the preferred method of TAAA repair.

Chuter added: "We still have a long way to go before this approach can assume a prominent role in the treatment of TAAA. The devices are expensive, their availability is limited by government regulation and their safe use depends on unique skills."

This year's VEITHsymposium, sponsored by the Cleveland Clinic, was started by vascular surgeon Frank Veith, MD, of Cleveland Clinic, and this year was attended by about 2,000 people.