Carotid artery stenting (CAS) with a proximal cerebral protection device in patients presenting with string sign at carotid angiography is a feasible, safe solution and exhibits low complication rates compared to carotid endarterectomy (CAE), according to a study in the March issue of the Journal of the American College of Cardiology: Cardiovascular Interventions.
“High-grade internal carotid artery (ICA) stenosis might be associated with angiographic appearance of a long, thin, tapered, post-stenotic segment of markedly reduced caliber with reduced anterograde flow. The angiographic appearance is called string sign, slim sign or atherosclerotic pseudo-occlusion,” the authors wrote. “Presence of string sign detected at carotid angiography has been correlated to high morbidity and mortality risk.”
Dimitrios N. Nikas, MD, PhD, of the Mirano Public Hospital in Mirano, Italy, and colleagues looked at 24 patients between October 2006 and August 2007 with string sign to assess the effectiveness of CAS with proximal cerebral protection.
Previously, CEA has been performed as a treatment for these string sign patients, but higher rates of thromboembolic complication and stroke were reported.
During the study, researchers evaluated acute and one-year outcomes of 21 men and four women with an average age of 71 representing with string sign.
Twenty of the patients were symptomatic—presence of stroke, transient ischemic attacks (TIA) or amaurosis within six months of angiography—while the rest were asymptomatic. Single TIAs, repeat and recent TIAs, incidence of stroke and acute stroke with reperfusion were reported in five, 11, three and one of the patients, respectively.
If not already administered clopidogrel, patients were administered a 300 mg oral clopidogrel dose and a 250 mg loading dose of aspirin daily. Additionally, a bolus dose of heparin was administered to activate 250 to 300 seconds coagulation times during the procedure.
Two proximal protection devices were used: the Mo.Ma (Invatec) in 16 patients and the Gore Flow Reversal System (W.L. Gore) in five patients. The Mo.Ma was unsuccessful in one patient where a guiding catheter and a filter-type distal protection device were then used.
“Procedural and clinical success was achieved in all patients,” the authors wrote.
One patient did develop groin hematoma after the procedure but was treated and resolved without blood transfusion in five days. According to the authors, proximal protection was successful in 24 patients (96 percent) and one patient developed acute MI 21 days post-procedure.
The results showed that 30-day major adverse cardiac and cerebral events were 4 percent and one-year stroke and mortality rates were also 4 percent.
“The increasing experience in CAS techniques, the improvement of devices and the availability of new proximal cerebral protection systems led us to the assumption that CAS might be a feasible and safe option to treat symptomatic patients with string sign,” the authors noted. However, they said that performance of CAS in asymptomatic patients remains unclear.
“Whether universal application of carotid stenting as a treatment modality in patients with carotid disease and string sign will reduce future stroke events needs to be clarified further with larger controlled trials,” the authors concluded.
In an accompanied editorial, Jay S. Yadav, MD, or the Piedmont Heart Institute in Atlanta, wrote that “the decision to revascularize a patient with a carotid string sign remains complex and should be made after careful deliberation.”
In addition, Yadav offered that while use of proximal occlusion devices “have migrated beyond acute stroke, perfusion imaging is a standard technique in evaluating patients with carotid occlusions who might benefit from extracranial to intracranial bypass surgery."