What can be done for cerebral embolic protection in TAVI? Analysis in the light of 10 years' experience with protected carotid artery stenting

In the last 30 years, development of minimally invasive percutaneous procedures to treat cardiovascular defects has been thriving. Although these techniques present obvious advantages, like avoiding cardiopulmonary bypass, the passage of catheter systems and the deployment of devices in the blood circulation can cause particle embolization that may result in stroke. In carotid artery stenting, cerebral embolic protection devices (CEPD) such as filtering membranes have been available for already 10 years. In transcatheter aortic valve implantation (TAVI), the development of CEPD is starting and three membrane-based devices are in clinical trials. There are controversial discussions about the efficacy of CEPD in TAVI. The experience with CEPD in carotid artery stenting can help to understand some of the technical issues and shortcomings of current devices and thereby ultimately reduce cerebral complication risks during TAVI procedures.

Carotid artery stenting: patient, lesion, and procedural characteristics that increase procedural complications

From the earliest experiences with carotid artery stenting (CAS) presumptive high risk features have included thrombus-containing lesions, heavily calcified lesions, very tortuous vessels, and near occlusions. In addition patients have been routinely excluded from CAS trials if they have contra-indications to dual antiplatelet therapy (aspirin and thienopyridines), a history of bleeding complications and severe peripheral arterial disease (PAD) making femoral artery vascular access difficult. Variables that increase the risk of CAS complications can be attributed to patient characteristics, anatomic or lesion features, and procedural factors. Clinical features such as older age (≥80 years), decreased cerebral reserve (dementia, multiple prior strokes, or intracranial microangiopathy) and angiographic characteristics such as excessive tortuosity (more than two 90° bends within 5 cm of the target lesion) and heavy calcification (concentric calcification ≥ 3 mm in width) have been associated with increased CAS complications. Other high risk CAS features include those that prolong catheter or guide wire manipulation in the aortic arch, make crossing a carotid stenosis more difficult, decrease the likelihood of successful deployment or retrieval of an embolic protection device (EPD), or make stent delivery or placement more difficult. Procedure volume for the operator and the catheterization laboratory team are critical elements in reducing the risk of the procedure. In this article, we help CAS operators better understand procedure risk to allow more intelligent case selection, further improving the outcomes of this emerging procedure.

Initial experience with a reversal-of-flow cerebral protection device in carotid angioplasty

PURPOSE: To report initial findings with the GORE Flow Reversal System®, with a focus on major/minor adverse events in the 30 first postoperative days. METHODS: The first 24 patients submitted to carotid angioplasty using the GORE system, from June 2010 to May 2012, were retrospectively assessed with regard to indications, anatomic details, technical difficulties, and early clinical outcomes, including major (stroke, death, acute myocardial infarction) and minor (hematoma) adverse events. RESULTS: Systemic hypertension was present in 100% of the patients, diabetes mellitus in 58.3%, and coronary disease in 37.5%. Type II aortic arch was encountered in 62.5% of the patients and atherosclerotic lesion predominantly at the carotid bifurcation affecting the internal and common carotid arteries in 79.2%. Angiographic data revealed contralateral carotid arteries with <50% stenosis in 95.8% of cases and preservation of cerebral blood flow in 95.8%. All procedures but one were technically successful. Mean cerebral flow reversal time was 14.9 minutes, with a statistically significant difference between the first 12 (17.9 minutes) and the last 12 patients treated (11.6 minutes) (p<0.001). Intolerance to flow reversal was observed in 17.4% of the cases. Technical difficulties were experienced in 1 patient (4.2%). Clinical outcomes included 4.2% of stroke and 12.5% of hematomas at arterial puncture sites. CONCLUSION: The system was technically effective. A significant reduction in cerebral flow reversal time was observed, and the rates of early major/minor adverse events were within acceptable limits, suggesting that the device is safe and effective.

First clinical experience with the GARDEX EPD: a novel embolic protection device for carotid artery stenting

AIMS

Carotid artery stenting (CAS) has become an alternative to carotid endarterectomy in the treatment of carotid artery disease. The use of an embolic protection device (EPD) can reduce the frequency of embolic events during CAS. Difficult vascular anatomy may complicate current generation EPD placement. This problem is addressed by a new EPD, the GARDEX System. The aim of this study was to assess the safety and performance of the GARDEX EPD during CAS.

METHODS AND RESULTS

Thirty-eight patients underwent CAS with the GARDEX EPD in two medical centres. All patients were prospectively followed up for 30 days. Device performance and procedural details were collected and analysed prospectively. Vessel anatomy and lesion morphology were evaluated and stratified into a scoring system for anatomic difficulty. More than a third of the patients were considered to have difficult vascular anatomy for CAS. All enrolled patients were successfully treated. There was one (2.6%) minor periprocedural stroke and there were two (5.3%) periprocedural TIAs which resolved within 24 hours. No additional complications were noted during the 30-day follow-up period.

CONCLUSIONS

In this first experience, CAS under cerebral protection with the GARDEX EPD was safe and feasible. Our data suggest that the use of the GARDEX EPD is simple and shows high success rates even in challenging anatomies. The role of this new device in CAS needs to be further confirmed in a larger patient population.