Atherosclerotic Plaque Composition and Cerebral Embolization after Carotid Stenting

Abstract

Conclusions:The RUC Committee uses information gathered by subjective surveys rather than by prospectively collecting accurate workload data. This unique study demonstrates a real-world experience of reimbursement per unit time and raises questions about the validity of the RBRVS process. The disparity between payments for open and endovascular repair of similar conditions, such as aortic aneurysm and carotid stenosis, are typical of this inequality. These data do not reflect the intangible time of operative planning, administrative matters, or overhead, and these are factors that must be considered when interpreting this information. Regardless, this study suggests that capturing detailed financial data is possible and is a more accurate source for future discussions on reimbursement. Cerebral Microembolization: Open vs Percutaneous Carotid RevascularizationBackground: A cumulative burden of data suggest that microembolization to the brain may result in long-term cognitive dysfunction despite the absence of immediate overt cerebrovascular events. We reviewed a series of patients treated electively with carotid endarterectomy (CEA), carotid stenting with filter (CAS), and carotid stenting with flow reversal (FRS) monitored continuously with transcranial Doppler (TCD) imaging during the procedure to detect microembolization rates.Methods: TCD insonation of the M1 segment of the middle cerebral artery was conducted during 39 procedures (14 CEA, 18 CAS, and 7 FRS) in 38 patients seen at an academic center. One patient had staged bilateral CEAs. TCD detects intraprocedural microemboli as high-intensity transient signals (HITS). Cerebral blood flow dynamics and HITS were monitored ipsilaterally for CEA patients and bilaterally for CAS and FRS patients. Ipsilateral HITS were divided into three phases: preprotection phase (until the internal carotid artery was cross-clamped or shunted, filter deployed, or flow reversal established), protection phase (until clamp/shunt removed, filter removed, or antegrade flow re-established), and postprotection phase (after clamp/shunt removed, filter removed, or antegrade flow re-established). Descriptive statistics are reported as mean Ϯ standard error for continuous variables and number (%) for categoric variables. Differences in ipsilateral emboli counts based on cerebral protection strategy were assessed using nonparametric methods (Kruskal-Wallis test).Results: TCD insonation and procedural success was obtained in 29 procedures (13 CEA, 11 CAS, and 5 FRS). Groups did not differ in baseline demographics. Total ipsilateral HITs were significantly different across all three groups (P Ͻ .001) as well as by separate two-group comparisons: CEA vs CAS (P Ͻ .001), CEA vs FRS (P ϭ .002), and FRS vs CAS (P ϭ .027; Table).