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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.Recommended
