Embolic Protection Devices for Carotid Artery Stenting: Have They Made a Significant Difference in Outcomes?

Paracentral acute middle maculopathy following internal carotid artery stenting

Purpose

To report a case of paracentral acute middle maculopathy (PAMM) that presented after internal carotid artery stenting despite the use of a filter embolic protection device.

Observations

A 74-year-old man presented one week following transfemoral stenting of the right internal carotid artery for high-grade stenosis. A filter-type embolic protection device was used during the stenting procedure to prevent distal embolization of atherosclerotic debris. Dilated examination of the right eye revealed a parafoveal gray lesion in the macula and optical coherence tomography showed a corresponding placoid hyperreflective band at the level of the inner nuclear layer consistent with PAMM. The patient was asymptomatic. At 10 weeks follow up the PAMM lesion was resolved.

Conclusions

PAMM occurred following internal carotid artery stenting despite the use of a filter embolic protection device, likely due to embolic debris passing through the filter device or debris released while the filter was in a collapsed state. The PAMM lesion was small and resolved without visual sequelae.

Assessing the impact of distal protection filter design characteristics on 30-day outcomes of carotid artery stenting procedures

OBJECTIVE

This study aims to review retrospectively the records of patients treated with carotid artery stenting (CAS) to investigate the potential correlations between clinical variables, distal protection filter (DPF) type and characteristics, and 30-day peri-/postprocedural outcomes.

METHODS

This is a multicenter, single-arm, nonrandomized retrospective study of patients who underwent filter-protected CAS in the Pittsburgh, Pennsylvania, region between July 2000 and May 2011. Analysis of peri-/postprocedural complications included myocardial infarction, transient ischemic attacks (TIA), stroke, death, and a composition of all adverse events (AEs). Filter characteristics for Accunet (Abbott Vascular, Santa Clara, Calif; n = 429 [58.8%]), Angioguard (Cordis Endovascular, Miami Lakes, Fla; n = 114 [15.6%]), FilterWire (Boston Scientific, Natick, Mass; n = 113 [15.5%]), Spider (ev3 Endovascular, Plymouth, Minn; n = 45 [6.2%]), and Emboshield (Abbott Vascular; n = 24 [3.3%]) were previously determined in vitro and were used to find correlations with CAS procedural outcomes. Both univariate and multivariate analyses were performed, as well as goodness-of-fit tests to find multivariate correlations with procedural outcomes.

RESULTS

In total, 731 CAS procedures using six different DPFs were analyzed. Peri-/postprocedural AEs included 19 TIAs (2.6%), 38 strokes (5.2%), one myocardial infarction (0.1%), 19 deaths (3.6%), and a total of 61 patients with complications (8.3%). Univariate analysis for filter design characteristics showed that the composite of AE was negatively associated with both vascular resistance (P = .01) and eccentricity (P = .02) and was positively associated with porosity (P = .0007), number of pores (P = .005), and pore density (P = .001). Multivariate analysis and the goodness-of-fit test revealed that patients with a history of congestive heart failure, stroke, and TIA (each with odds ratio >1) led to a good-fit model P value of .72 for peri-/postprocedural AEs. Multivariate analysis was inconclusive for all filter design characteristics.

CONCLUSIONS

The following filter design characteristics are independently significant for minimizing peri-/postprocedural AEs: higher vascular resistance, concentric in shape, greater capture efficiency, lower porosity, lower number of pores, and lower pore density. Lower porosity and smaller wall apposition were also found to be independently significant for minimization of peri-/postprocedural TIAs. This information can be used when considering the desirable design characteristics of future DPFs.).

Cerebral Intolerance During Flow Arrested Carotid Angioplasty

Introduction: The use of flow arrest as a means of providing cerebral protection during carotid angioplasty offers the advantages of improved efficiency of debris removal and the ability to provide protection under unfavorable (tortuous) anatomic circumstances. However, in contrast to the filtration methods of cerebral protection, this modality requires complete interruption of antegrade carotid artery flow during balloon angioplasty and stent deployment. Methods: We report our experience with 9 patients undergoing carotid angioplasty with the Mo.Ma device, which utilizes common and external carotid artery balloon occlusion during the angioplasty procedure. We assessed the clinical outcomes and intraprocedural hemodynamic data. Results: The average duration of carotid occlusion was 8.3 minutes. Of the 9 patients, 2 patients (22%) experienced cerebral intolerance. No stroke occurred in this patient cohort. There appeared to be a poor relationship between procedure intolerance and the presence of significant contralateral stenosis or low carotid back pressure. Furthermore, the incidence of postangioplasty hypotension was not clearly related to cerebral intolerance. Conclusion: Carotid angioplasty with stenting can be safely conducted with flow arrest as an alternative to filter-type cerebral protection devices. However, because cerebral intolerance is not an infrequent occurrence with this approach, clinicians must be cognizant of management strategies for transient cerebral intolerance.