View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector From the Southern Association for Vascular Surgery The incidence of microemboli to the brain is less with endarterectomy than with percutaneous revascularization with distal filters or flow reversal Naren Gupta, MD, PhD,a Matthew A. Corriere, MD, MS,a,c Thomas F. Dodson, MD,a Elliot L. Chaikof, MD, PhD,a Robert J. Beaulieu, BS,b James G. Reeves, MD,a Atef A. Salam, MD,a and Karthikeshwar Kasirajan, MD,a Atlanta, Ga Background: Current data suggest microembolization to the brain may result in long-term cognitive dysfunction despite the absence of immediate clinically obvious cerebrovascular events. We reviewed a series of patients treated electively with carotid endarterectomy (CEA), carotid artery stenting (CAS) with distal filters, and carotid stenting with flow reversal (FRS) monitored continuously with transcranial Doppler scan (TCD) during the procedure to detect microembolization rates. Methods: TCD insonation of the M1 segment of the middle cerebral artery was conducted during 42 procedures (15 CEA, 20 CAS, and 7 FRS) in 41 patients seen at an academic center. One patient had staged bilateral CEA. Ipsilateral microembolic signals (MESs) were divided into three phases: preprotection phase (until internal carotid artery [ICA] cross-shunted or clamped if no shunt was used, filter deployed, or flow reversal established), protection phase (until clamp/shunt was removed, filter removed, or antegrade flow re-established), and postprotection phase (after clamp/ shunt was removed, filter removed, or antegrade flow re-established). Descriptive statistics are reported as mean ؎ SE for continuous variables and N (%) for categorical variables. Differences in ipsilateral emboli counts based on cerebral protection strategy were assessed using nonparametric methods. Results: TCD insonation and procedural success were obtained in 33 procedures (79%; 14 CEA, 14 CAS, and 5 FRS). ؎ Highest ipsilateral MESs were observed for CAS (319.3 ؎ 110.3), followed by FRS (184.2 ؎ 110.5), and CEA (15.3 22.0). Pairwise comparisons revealed significantly higher ipsilateral MESs with both FRS and CAS when compared to for FRS and P < .001 for CAS vs CEA, respectively), whereas the difference in MESs between FRS and 007. ؍ CEA (P Periods of maximum embolization were postprotection phase for CEA, protection .(053. ؍ CAS was not significant (P phase for CAS, and preprotection phase for FRS. Preprotection MESs were frequently observed during both CAS and FRS (20.4% and 63.3% of total MESs across all phases, respectively), and the primary difference between these two methods seemed to be related to lower MESs during the protection phase with FRS. Conclusion: CEA is associated with lower rates of microembolization compared with carotid stenting. Flow reversal may represent a procedural modification with potential to reduce microembolization during carotid stenting; further investigation is warranted to determine the relationship between cerebral protection strategies and outcomes associated with carotid stenting. (J Vasc Surg 2011;53:316-22.) Stroke affects nearly 800,000 United States citizens annu- sive alternative to CEA with the Stenting with Angioplasty ally and is the third most common cause of death in the and Protection in Patients at High Risk for Endarterectomy United States.1 Almost 20% of strokes are due to atheroscle- (SAPPHIRE) trial, which concluded that CAS was noninfe- rotic disease of the extracranial carotid arteries.2 The surgical rior to CEA in a high-risk group of patients, despite higher removal of the source of emboli or flow limitation by carotid stroke rates in the CAS arm.7 Four subsequent prospective endarterectomy (CEA) has been shown to decrease the risk of randomized trials have all demonstrated higher stroke rates stroke compared to medical therapy alone.3-6 Carotid angio- with CAS compared to CEA.8-11 The recent Carotid Revas- plasty stenting (CAS) gained acceptance as a minimally inva- cularization Endarterectomy vs Stenting Trial deployed a late- generation stent with 96% distal filter deployment and vigor- From the Division of Vascular Surgery and Endovascular Therapy, Depart- ous credentialing of interventionalists, yet reported that the ment of Surgery,a School of Medicine,b Department of Epidemiology, c impact on quality of life of the increased number of strokes Rollins School of Public Health, Emory University. ϭ Competition of interest: none. after CAS (4.1% vs 2.3%; P .01) was more than that due to Presented at the Thirty-fourth Annual Meeting of the Southern Association increased cardiac events after CEA (1.1% vs 2.3%; for Vascular Surgery, Paradise Island, Bahamas, January 21, 2010. P ϭ .03).11 Reprint requests: Karthikeshwar Kasirajan, MD, Associate Professor, Divi- Intracerebral microembolization is implicated in the sion of Vascular Surgery, Emory University Hospital, 1365 A Clifton Road NE, 3rd Floor, Atlanta, GA 30322 (e-mail: [email protected]). increased cerebral events after percutaneous revasculariza- The editors and reviewers of this article have no relevant financial relationships tion.12,13 Distal embolic protection filtering devices were to disclose per the JVS policy that requires reviewers to decline review of any introduced to reduce microembolization but do not com- manuscript for which they may have a competition of interest. pletely eliminate this phenomenon due in part to the lack of 0741-5214/$36.00 Copyright © 2011 by the Society for Vascular Surgery. protection during instrumentation of the aortic arch and doi:10.1016/j.jvs.2010.08.063 initial passage across the carotid lesion and a failure to 316 JOURNAL OF VASCULAR SURGERY Volume 53, Number 2 Gupta et al 317 Table I. Baseline patient characteristics CEA (N ϭ 14) CAS (N ϭ 14) FRS (N ϭ 5) Total (N ϭ 33) Mean age 72 Ϯ 8 67.5 (64.2-73.2) 63.1 (58.8-67.1) 68.0 (63.3-77.6) Male 10 (71.4) 11 (78.6) 5 (100) 26 (78.8) Symptomatic 7 (50) 5 (35.7) 3 (60) 15 (45.5) DM 9 (64.3) 7 (50) 3 (60) 19 (57.6) CHF (NYHA III or IV) 2 (14.3) 1 (7.1) 3 (60) 6 (18.2) CAD 2 (14.3) 5 (35.7) 3 (60) 10 (30.3) COPD (FEV1Ͻ1) 0 (0) 4 (28.5) 2 (40) 6 (18.2) Previous MI 6 (42.9) 5 (35.7) 3 (60) 14 (42.4) Tobacco Ͻ1 y 4 (28.6) 6 (42.9) 0 (0) 10 (30.3) CRI (Cr Ͼ1.4) 3 (21.4) 3 (21.4) 2 (40) 8 (24.4) HTN 14 (100) 14 (100) 4 (80) 32 (96.8) PVD 3 (21.4) 8 (57.1) 2 (40) 13 (39.4) Hyperlipidemia 10 (71.4) 12 (85.7) 4 (80) 26 (78.8) Right-sided lesion 5 (35.7) 3 (21.4) 5 (100) 13 (39.3) Irradiated neck 0 (0) 4 (28.5) 0 (0) 4 (12.1) Restenosis 1 (7.1) 1 (7.1) 0 (0) 2 (6.1) C/L disease 80% to 99% 1 (7.1) 2 (14.3) 0 (0) 3 (9.1) C/L occlusion 1 (7.1) 1 (7.1) 2 (40) 4 (12.1) Bovine arch N/A 2 (14.3) 0 (0) 2 (10.5) Type II or III arch N/A 9 (64.3) 5 (100) 14 (73.7) CAD, Coronary artery disease; CAS, carotid artery stenting; CEA, carotid endarterectomy; CHF, congestive heart failure; C/L, contralateral; COPD, chronic obstructive pulmonary disease; Cr, creatinine; CRI, chronic renal insufficiency; DM, diabetes mellitus; FEV1, forced expiratory volume in 1 second; FRS, flow reversal stenting; HTN, hypertension; N/A, not applicable; NYHA, New York Hospital Association; MI, myocardial infarction; PVD, peripheral vascular disease. Data displayed as mean Ϯ SD for continuous variables and number (percent) for categorical variables. capture all emboli after deployment.14,15 Flow reversal was removed, filter removed, or antegrade flow re-estab- (FRS) is an embolic protection method that addresses some lished), and postprotection phase (after clamp/shunt was of the shortcomings of distal filters by reversing the direc- removed, filter removed, or antegrade flow re-established). tion of blood flow in the distal internal carotid artery (ICA). Patients. Between December 2008 and December A commercial FRS system received Food and Drug Admin- 2009, a total of 163 carotid revascularization procedures istration approval to be marketed in the United States in (83 CEA, 59 CAS, and 21 FRS) were performed at this February 2009.16,17 institution. Treatment for asymptomatic disease was of- Microemboli are detected as high-intensity unidirec- fered for stenosis greater than 80% by North American tional transient signals on transcranial Doppler (TCD) scan Symptomatic Carotid Endarterectomy Trial criterion, and imaging during the procedure.18 These microembolization for symptomatic patients, the cutoff was Ͼ70%.6 Stenosis signals (MESs) correspond to gaseous or particulate em- was determined by duplex ultrasound scan imaging. Patient bolic material: both are related to adverse clinical out- selection for TCD monitoring was based on the availability comes.19-21 There is evidence that MESs may also contrib- of a technician. Forty-two (25.2% of the total caseload) ute to vascular dementia and Alzheimer’s disease.22 carotid revascularization procedures (15 CEA, 20 CAS, Monitoring of MESs by TCD has been used as a quality and 7 FRS) in 41 individuals (1 patient had staged bilateral control method during both open and percutaneous carotid CEA) had TCD monitoring and their data were prospec- revascularization.23,24 The objective of this study was to de- tively entered into a database. Procedures were aborted in termine MES rates during elective CEA, carotid angioplasty, three instances (7.1%; 2 CAS, 1 FRS): 1 patient for CAS and stenting with distal embolic protection device or carotid had a calcified type III arch leading to an inability to angioplasty and stenting with flow reversal (FRS).