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JOURNAL OF VASCULAR SURGERYDecember 20121584 Tulip et al

11. Timaran CH, McKinsey JF, Schneider PA, Littooy F. Reporting stan-dards for carotid interventions from the Society for Vascular Surgery. JVasc Surg 2011;53:1679-95.

12. Beneficial effect of carotid endarterectomy in symptomatic patients withhigh-grade carotid stenosis. North American Symptomatic CarotidEndarterectomy Trial Collaborators. N Engl J Med 1991;325:445-53.

13. Ohki T, Timaran CH, Yadav JS. Technique of carotid angioplastyand stenting. In: Moore WS, editor. Vascular and endovascularsurgery: a comprehensive review. Philadelphia: Saunders Elsevier;2006. p. 355-82.

14. Timaran CH, Rosero EB, Martinez AE, Ilarraza A, Modrall JG, ClagettGP. Atherosclerotic plaque composition assessed by virtual histologyintravascular ultrasound and cerebral embolization after carotid stent-ing. J Vasc Surg 2010;52:1188-94.

15. Ringelstein EB, Droste DW, Babikian VL, Evans DH, Grosset DG,Kaps M, et al. Consensus on microembolus detection by TCD. Inter-national Consensus Group on Microembolus Detection. Stroke 1998;29:725-9.

16. Silver FL, Mackey A, Clark WM, Brooks W, Timaran CH, Chiu D, et al.Safety of stenting and endarterectomy by symptomatic status in theCarotid Revascularization Endarterectomy Versus Stenting Trial(CREST). Stroke 2011;42:675-80.

17. Kakkos SK, Sabetai M, Tegos T, Stevens J, Thomas D, Griffin M, et al.Silent embolic infarcts on computed tomography brain scans and risk ofipsilateral hemispheric events in patients with asymptomatic internalcarotid artery stenosis. J Vasc Surg 2009;49:902-9.

18. Markus HS, Thomson ND, Brown MM. Asymptomatic cerebral em-bolic signals in symptomatic and asymptomatic carotid artery disease.Brain 1995;118:1005-11.

19. Markus HS, MacKinnon A. Asymptomatic embolization detected by

Doppler ultrasound predicts stroke risk in symptomatic carotid arterystenosis. Stroke 2005;36:971-5. S

mother-in-law! Based on these data, the authors rightly question if

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0. King A, Shipley M, Markus H; ACES Investigators. Optimizing proto-cols for risk prediction in asymptomatic carotid stenosis using embolicsignal detection: the Asymptomatic Carotid Emboli Study. Stroke2011;42:2819-24.

1. Abbott AL. Medical (nonsurgical) intervention alone is now best forprevention of stroke associated with asymptomatic severe carotid steno-sis: results of a systematic review and analysis. Stroke 2009;40:e573-83.

2. Rothwell PM. Carotid stenting: more risky than endarterectomy andoften no better than medical treatment alone. Lancet 2010;375:957-9.

3. Spence JD, Coates V, Li H, Tamayo A, Muñoz C, Hackam DG, et al.Effects of intensive medical therapy on microemboli and cardiovascularrisk in asymptomatic carotid stenosis. Arch Neurol 2010;67:180-6.

4. Marquardt L, Geraghty OC, Mehta Z, Rothwell PM. Low risk ofipsilateral stroke in patients with asymptomatic carotid stenosis on bestmedical treatment: a prospective, population-based study. Stroke 2010;41:e11-7.

5. Moore WS, Barnett HJ, Beebe HG, Bernstein EF, Brener BJ, Brott T,et al. Guidelines for carotid endarterectomy. A multidisciplinary con-sensus statement from the ad hoc committee, American Heart Associ-ation. Circulation 1995;91:566-79.

6. Biller J, Feinberg WM, Castaldo JE, Whittemore AD, Harbaugh RE,Dempsey RJ, et al. Guidelines for carotid endarterectomy: a statementfor healthcare professionals from a special Writing Group of the strokecouncil, American Heart Association. Circulation 1998;97:501-9.

7. Chimowitz MI, Lynn MJ, Derdeyn CP, Turan TN, Fiorella D, LaneBF, et al. Stenting versus aggressive medical therapy for intracranialarterial stenosis. N Engl J Med 2011;365:993-1003.

8. Endarterectomy for asymptomatic carotid artery stenosis. Executivecommittee for the Asymptomatic Carotid Atherosclerosis Study. JAMA1995;273:1421-8.

ubmitted Feb 27, 2012; accepted Jun 1, 2012.

DISCUSSION

Dr Charles Sternbergh, III (New Orleans, La). Dr Tulip andcolleagues bring us important and timely data today, emblematicof the insightful research we have come to expect from the vasculargroup at University of Texas Southwestern. In this study, 40patients underwent carotid artery stenting (CAS), 23 for asymp-tomatic and 17 for symptomatic disease. Subclinical evidence ofcerebral emboli was studied with intraprocedural transcranialDoppler and diffusion-weighted magnetic resonance imaging(DW-MRI) scans obtained preoperatively and postoperatively.

If this study cohort and design sounds familiar to this audi-ence, it should. At this meeting in January 2011, the identicalpatient cohort was presented, with the same outcome parametersof transcranial Doppler hits and new DW-MRI brain lesions. Thatrandomized, prospective trial compared open-cell vs closed-cellstents, and no difference between groups was seen in subclinicalemboli.1

Today, the study instead provides the subcohort data onasymptomatic vs symptomatic patients. A sobering 50% rate ofischemic brain injury was seen on DW-MRI in both groups. If thelate John Porter were still with us today, his Yearbook of VascularSurgery might have bestowed the authors with the dreaded“salami-slicer” award for parsing out pieces of data into multiplepublications instead of in a single communication.

But here’s the thing: I understand why the authors chose notto include these patient cohorts in the original publication. Theimpact of the data might have been lost, or at least diminished.Although the long-term clinical significance of these DW-MRIlesions is uncertain, a 50% rate of acute brain injury, even ifclinically asymptomatic, cannot be a good thing. I would not wishmy mother to be subjected to such odds—gee, not even my

lter-protected CAS in asymptomatic patients should be per-ormed. I have two questions for the authors:

First, based on the presented data, do the authors feel it isthical to offer CAS with filter protection to a patient with asymp-omatic disease?

Second, flow-reversal or flow cessation protection has shownromise in decreasing subclinical cerebral emboli in symptomaticatients undergoing CAS. Has your group shifted to such embolicrotection techniques, even in asymptomatic patients?

Dr Hans H. Tulip. Thank you, Dr Sternberg, I appreciateour questions. In answer to your first question, I do feel that CASs safe for patients with asymptomatic carotid artery stenosis basedn current data. Because we do not know the effects of these silenterebral emboli, carotid endarterectomy should be considered inatients who are fit for open surgery. From here, we need to focusur efforts on identifying the subset of asymptomatic patients thatre more likely to benefit from surgery. Once this group is identi-ed, carotid stenting and endarterectomy will provide maximalenefit at acceptable risk to these patients. In answer to yourecond question, we are beginning to enroll patients in an Ameri-an Heart Association–funded trial to determine the role for prox-mal balloon occlusion and flow reversal compared with filtermbolic protection devices to determine whether this reduces thencidence of these subclinical cerebral embolization and neuro-ogic events.

EFERENCE

. Timaran CH, Rosero EB, Higuera A, Ilarraza A, Modrall JG, Clagett GP.Randomized clinical trial of open-cell vs closed-cell stents for carotid

stenting and effects of stent design on cerebral embolization. J Vasc Surg2011;54:1310-6.