Carotid ultrasonography predicts collateral development following combined direct and indirect revascularization surgery in adult ischemic Moyamoya disease.

OBJECTIVE: The relationship between carotid ultrasonographic parameters and postoperative collateral development in adult ischemic moyamoya disease (MMD) patients who received combined direct and indirect revascularization surgery remains unclear. Herein, we investigated the postoperative changes in carotid ultrasonographic parameters in patients with adult ischemic MMD. METHODS: We studied 28 adult ischemic MMD patients (31 hemispheres) who underwent combined revascularization surgery. Patients underwent preoperative and postoperative (within 14 days and 3, 12, and 24 months after surgery) magnetic resonance imaging and carotid ultrasonography. We defined the hemisphere in which all signal intensities of the superficial temporal, middle meningeal, and deep temporal arteries were increased compared with that before surgery on magnetic resonance angiography as well-developed collateral establishment. RESULTS: Patients with good collateral establishment on MRA at 2-year after surgery had a lower external carotid artery (ECA) pulsatility index (PI) (P = 0.0413) and ECA/internal carotid artery (ICA) pulsatility index (PI) ratio (P = 0.0427) at 3-month post-operation. At 3-month post-operation, a cut-off ECA PI of 1.416 (sensitivity 40.0 %, specificity 92.3 %, area under the curve 0.7282, likelihood ratio 5.20, P = 0.0404) and ECA/ICA PI ratio of 0.8768 (sensitivity 50.0 %, specificity 92.31 %, area under the curve 0.7308, likelihood ratio 6.50, P = 0.0415) provided reliable values for good prediction of collateral development at 2 years after revascularization. CONCLUSION: ECA/ICA PI ratio and ECA PI at 3-month after surgery can be one of the indicators for predicting future well-developed neovascularization on MRA and better outcome in patients with adult ischemic MMD who received combined direct and indirect revascularization surgery.

Peak systolic velocity and color aliasing are important in the development of duplex ultrasound criteria for external carotid artery stenosis.

OBJECTIVE: The external carotid artery (ECA) serves as a major collateral pathway for ophthalmic and cerebral artery blood supply. It is routinely examined as part of carotid duplex ultrasound, but criteria for determining ECA stenosis are poorly characterized and typically extrapolated from internal carotid artery data. This is despite the fact that the ECA is smaller in diameter, with a higher resistance and lower volume flow pattern. We hypothesized that using the cutoff of a peak systolic velocity (PSV) ≥125 cm/s, extrapolated from internal carotid artery data, will overestimate the prevalence of ≥50% ECA stenosis and aimed to determine a more appropriate criterion. METHODS: From December 2016 to July 2017, consecutive carotid duplex ultrasound studies performed in our university hospital Intersocietal Accreditation Commission-accredited vascular laboratory were prospectively identified and categorized with respect to prevalence and distribution of ECA PSVs and color aliasing, an indication of turbulent flow or flow acceleration. Presence of color aliasing was determined by two individual reviewers and agreement assessed by Cohen κ coefficient. ECA stenosis was calculated by the North American Symptomatic Carotid Endarterectomy Trial (NASCET) method in patients with computed tomography angiography (CTA) performed within 3 months of carotid duplex ultrasound without an intervening intervention. Receiver operating characteristic analysis was performed to identify best criteria for determining ≥50% ECA stenosis. RESULTS: There were 1324 ECAs from 662 patients analyzed; 174 patients had a total of 252 ECAs with PSV ≥125 cm/s (19% of the total sample). Of those ECAs with PSVs ≥125 cm/s, 30.5% were between 125 and 149 cm/s, 22.2% were between 150 and 174 cm/s, 13.1% were between 175 and 199 cm/s, and 34.1% were ≥200 cm/s. There were 341 ECAs that were analyzed for the presence of color aliasing. In 86 ECAs with PSV ≥200 cm/s, 58.1% had color aliasing, whereas in 255 ECAs with PSV <200 cm/s, only 19.2% had color aliasing (P = .0001). There were 325 CTA studies reviewed and assessed for the presence of a ≥50% ECA stenosis as determined by CTA. Overall, the combination of an ECA PSV ≥200 cm/s with the presence of color aliasing provided the highest combination of sensitivity (90%), specificity (96%), positive predictive value (83%), and negative predictive value (98%) and the greatest area under the curve of 0.971 for determining the presence of a ≥50% ECA stenosis based on CTA. CONCLUSIONS: A PSV ≥125 cm/s alone probably overestimates the prevalence of ≥50% ECA stenosis. A PSV ≥200 cm/s combined with color aliasing is highly predictive of >50% ECA stenosis based on correlation with CTA.

Duplex Criteria for Grading of External Carotid Stenosis.

BACKGROUND: External carotid artery (ECA) stenosis is an independent mortality predictor. Additionally, concomitant ECA and internal carotid artery (ICA) stenosis progression has been associated with an increased risk of ipsilateral ischemic events in asymptomatic patients. Universally accepted ECA duplex velocity criteria, for the prediction of stenosis, do not exist. METHODS: Consecutive patients undergoing angiography and carotid duplex assessments were compared (n = 140). ICA, common carotid artery (CCA), and ECA peak systolic velocities (PSVs) were recorded. ECA/CCA PSV ratio was calculated. These parameters were compared with angiographic ECA measurements. Receiver-operator curve analysis was used to determine optimal criteria in identifying ECA stenosis of >50%. RESULTS: In patients with little ipsilateral ICA disease, for the detection of ECA stenosis of ≥50%, an ECA PSV >148 cm/sec provided a sensitivity of 80%, specificity of 76.2%, and an overall accuracy of 77.1%. An ECA/CCA PSV ratio of 1.45 demonstrated a sensitivity of 73.7%, specificity of 66.7%, and an accuracy of 68.2%.In patients with ICA stenosis ≥50%, for the detection of ECA stenosis of ≥50%, an ECA PSV >179 cm/sec provided a sensitivity of 50%, specificity of 79.6%, and overall accuracy of 71.3%. An ECA/CCA PSV ratio of ≥1.89 provided a sensitivity of 71.9%, specificity of 72.7%, and overall accuracy of 72.5%. CONCLUSIONS: ECA PSV and ECA/CCA PSV ratios appear as useful metrics for the prediction of unilateral high-grade ECA stenosis.

Early hemodynamic characteristics of eversion and patch carotid endarterectomies.

OBJECTIVE: Carotid endarterectomy (CEA) is currently the gold standard in the operative management of carotid artery stenosis. While eversion and patch CEAs vary greatly in technique, various studies have determined equivalence with regard to clinical outcomes. However, the hemodynamic differences following each procedure are not known. This study aimed to investigate any early hemodynamic differences between eversion and patch CEAs. METHODS: All CEAs performed at our institution from March 2012 to June 2018 were aggregated in a retrospective database by querying the 35301 CPT code from the electronic medical record system. Variables collected included gender, age, laterality of CEA, type of procedure, and pre- and post-operative duplex ultrasound (DUS) date and quantitative findings. Exclusion criteria included any procedure with incomplete data, a post-operative DUS > 90 days following the procedure, CEAs with concomitant bypass(es), isolated external carotid artery (ECA) endarterectomies, and re-do CEAs. RESULTS: One hundred and seventy-one CEAs were performed in 161 unique patients. There were 101 males and 60 females, with an average age of 69.7 (38-96; ± 9.36). 63 CEAs were excluded from analysis: 51 due to incomplete data, eight with a > 90 day post-operative DUS, 2 isolated ECA endarterectomies, 1 CEA with a carotid-subclavian bypass, and 1 re-do CEA secondary to an infected patch. Twenty-seven eversion and 81 patch CEAs were included in analysis. There was no difference in procedure laterality or gender between the two cohorts (p > 0.05); however, patients who received an eversion CEA were older on average (73.3 vs 67.5; p = 0.002). Pre-operative peak systolic velocities (PSV) of the proximal internal carotid artery (ICA), distal ICA, and distal common artery (CCA) were all similar (p > 0.05). Post-operative DUS was performed at 17.0 and 12.9 days in the eversion and patch CEA cohorts, respectively (p = 0.12). Post-operative PSV and change in PSV were similar for all three aforementioned segments (p > 0.05). CONCLUSION: Although eversion and patch CEAs vary greatly in technique and post-procedure anatomy, there was no significant difference in post-operative PSV or change in PSV at or around the carotid bifurcation.

Impact of external carotid artery occlusion at declamping of the external and common carotid arteries during carotid endarterectomy on development of new postoperative ischemic cerebral lesions.

OBJECTIVE: The external carotid artery (ECA) is inadvertently occluded during carotid endarterectomy (CEA). The importance of ECA occlusion has been emphasized as a loss of extracranial to intracranial collaterals, a source of chronic embolization, or a site for extended thrombosis during wound closure. This study aimed to determine whether ECA occlusion that inadvertently developed during endarterectomy and that was eventually detected using blood flow measurement of the ECA after declamping of all carotid arteries is a risk factor for development of new postoperative ischemic lesions at declamping of the ECA and common carotid artery (CCA) while clamping the internal carotid artery (ICA). This study also aimed to determine whether intraoperative transcranial Doppler (TCD) monitoring predicts the risk for development of such lesions. METHODS: This was a prospective observational study that included patients undergoing CEA for severe stenosis (≥70%) of the cervical ICA. When blood flow through the ECA measured using an electromagnetic flow meter decreased rapidly on clamping of only the ECA before carotid clamping for endarterectomy and was not changed by clamping of only the ECA after carotid declamping following endarterectomy, the patient was determined to have developed ECA occlusion. These patients underwent additional endarterectomy for the ECA. TCD monitoring in the ipsilateral middle cerebral artery was also performed throughout surgery to identify microembolic signals (MESs). Brain magnetic resonance diffusion-weighted imaging (DWI) was performed before and after surgery. RESULTS: There were 104 patients enrolled in the study. Eight patients developed ECA occlusion during surgery. The incidence of intraoperative ECA occlusion was significantly higher in patients without MESs at the phase of ECA and CCA declamping (8/12 [67%]) than in those with MESs (0/92 [0%]; P < .0001). Six patients exhibited new postoperative ischemic lesions on DWI. The incidence of intraoperative ECA occlusion (P < .0001) and the absence of MESs at declamping of the ECA and CCA while clamping the ICA (P <. 0001) were significantly higher in patients with development of new postoperative ischemic lesions on DWI than in those without. Sensitivity and specificity for the absence of MESs at declamping of the ECA and CCA while clamping the ICA for predicting development of new postoperative ischemic lesions on DWI were 100% (6/6) and 94% (92/98), respectively. CONCLUSIONS: ECA occlusion at declamping of the ECA and CCA while clamping the ICA during CEA is a risk factor for development of new postoperative ischemic lesions. Intraoperative TCD monitoring accurately predicts the risk for development of such lesions.

Cerebral Protection with a Temporary Ascending Aorta-External Carotid Artery Bypass during Common Carotid Artery Revascularization.

Atherosclerosis is a systemic disease, and multiarterial involvement is common. Involvement of all the supra-aortic arteries may occur in the same patient making cerebral revascularization challenging. In this report, we present complete supra-aortic revascularization, that is, revascularization of the bilateral common carotid and subclavian arteries in a 51-year-old male patient with occluded brachiocephalic trunk, left subclavian artery, and proximally stenotic left common carotid artery. A temporary ascending aorta to left external carotid artery bypass provided meticulous cerebral protection with pulsatile cerebral flow in the presence of a proximal arterial clamp; hence, a neurologically uneventful procedure during bilateral common carotid artery revascularization.

Mastication Steal Syndrome.

A 56-year-old woman presented with episodic vertigo, dizziness, and diplopia during meals and prolonged verbal presentations at work. Subsequent work-up included an eventual catheter-based angiogram revealing an ostial left external carotid artery (ECA) occlusion with reconstituted retrograde flow via a variant collateral branch from the dominant left vertebral artery. The findings demonstrate that repetitive activities involving craniofacial muscular systems supplied by the ECA result in a symptomatic arterial steal syndrome via the enhanced diverted flow from the collateral vertebral-basilar arterial system. A left ECA endarterectomy with reimplantation of the vessel was performed, and the patient has been episode free thereafter.

Differential Regulation of BMAL1, CLOCK, and Endothelial Signaling in the Aortic Arch and Ligated Common Carotid Artery.

The circadian clock is rhythmically expressed in blood vessels, but the interaction between the circadian clock and disturbed blood flow remains unclear. We examined the relationships between BMAL1 and CLOCK and 2 regulators of endothelial function, AKT1 and endothelial nitric oxide synthase (eNOS), in vascular regions of altered blood flow. We found that the aortic arch from WT mice exhibited reduced sensitivity to acetylcholine (Ach)-mediated relaxation relative to the thoracic aorta. In Clock-mutant (mut) mice the aorta exhibited a reduced sensitivity to Ach. In WT mice, the phosphorylated forms of eNOS and AKT were decreased in the aortic arch, while BMAL1 and CLOCK expression followed a similar pattern of reduction in the arch. In conditions of surgically induced flow reduction, phosphorylated-eNOS (serine 1177) increased, as did p-AKT in the ipsilateral left common carotid artery (LC) of WT mice. Similarly, BMAL1 and CLOCK exhibited increased expression after 5 days in the remodeled LC. eNOS expression was increased at 8 p.m. versus 8 a.m. in WT mice, and this pattern was abolished in mut and Bmal1-KO mice. These data suggest that the circadian clock may be a biomechanical and temporal sensor that acts to coordinate timing, flow dynamics, and endothelial function.

Long-Term Follow-Up for a Giant Basilar Trunk Aneurysm Surgically Treated by Proximal Occlusion and External Carotid Artery to Posterior Cerebral Artery Bypass Using a Saphenous Vein Graft.

The authors describe a case of a basilar trunk aneurysm with long-term follow-up after successful bypass and proximal occlusion. A 64-year-old woman had a giant aneurysm of the basilar trunk and underwent external carotid artery-to-posterior cerebral artery vein graft bypass surgery and proximal clipping of the basilar artery, which was followed by low-dose aspirin (100 mg/d) treatment. No ischemic symptoms and lesions developed and the thrombosed aneurysm was stable during 11 years of follow-up. An extracranial-intracranial high flow bypass combined with immediate proximal occlusion and aspirin administration may be an acceptable treatment option for patients with giant posterior circulation aneurysms.

Development of a Duplex Ultrasound Simulator and Preliminary Validation of Velocity Measurements in Carotid Artery Models.

OBJECTIVE: Duplex ultrasound scanning with B-mode imaging and both color Doppler and Doppler spectral waveforms is relied upon for diagnosis of vascular pathology and selection of patients for further evaluation and treatment. In most duplex ultrasound applications, classification of disease severity is based primarily on alterations in blood flow velocities, particularly the peak systolic velocity (PSV) obtained from Doppler spectral waveforms. We developed a duplex ultrasound simulator for training and assessment of scanning skills. METHODS: Duplex ultrasound cases were prepared from 2-dimensional (2D) images of normal and stenotic carotid arteries by reconstructing the common carotid, internal carotid, and external carotid arteries in 3 dimensions and computationally simulating blood flow velocity fields within the lumen. The simulator displays a 2D B-mode image corresponding to transducer position on a mannequin, overlaid by color coding of velocity data. A spectral waveform is generated according to examiner-defined settings (depth and size of the Doppler sample volume, beam steering, Doppler beam angle, and pulse repetition frequency or scale). The accuracy of the simulator was assessed by comparing the PSV measured from the spectral waveforms with the true PSV which was derived from the computational flow model based on the size and location of the sample volume within the artery. RESULTS: Three expert examiners made a total of 36 carotid artery PSV measurements based on the simulated cases. The PSV measured by the examiners deviated from true PSV by 8% ± 5% (N = 36). The deviation in PSV did not differ significantly between artery segments, normal and stenotic arteries, or examiners. CONCLUSION: To our knowledge, this is the first simulation of duplex ultrasound that can create and display real-time color Doppler images and Doppler spectral waveforms. The results demonstrate that an examiner can measure PSV from the spectral waveforms using the settings on the simulator with a mean absolute error in the velocity measurement of less than 10%. With the addition of cases with a range of pathologies, this duplex ultrasound simulator will be a useful tool for training health-care providers in vascular ultrasound applications and for assessing their skills in an objective and quantitative manner.

Elliptical transection for eversion endarterectomy enables efficient external carotid artery desobliteration.

BACKGROUND: Eversion endarterectomy (EEA) of the internal carotid artery requires less distal surgical exposure than conventional patch reconstruction endarterectomy. However, the technical success after EEA was tremendously contradictive especially with respect to the external carotid artery (ECA) patency rate. The purpose of this study was to determine the effect of elliptical EEA on the quality and outcome of external carotid artery desobliteration. METHODS: Clinical outcome and carotid disease progression at one year were evaluated in thirty patients receiving EEA through short transverse skin incision either in general anesthesia (GA, 22 patients) or locoregional anesthesia (LRA, 8 patients). RESULTS: One patient (GA group) required early revision for bleeding. There was no postoperative stroke, nerve damage or death. At one year, ipsilateral systolic peak velocity (SPV) measurements showed no disease progression in the internal (75.30±19.31; 62.88±28.51 cm/s) or in the external carotid artery (118.92±58.30; 79.00±27.15 cm/s, GA; RLA, respectively). The incidence of ipsilateral ECA stenosis >50% decreased from 64% preoperatively to 16 % at one year (P<0.001). On the contralateral side, incidence of ECA stenosis >50% increased from 27% preoperatively to 56% after one year (p=0.018). On the ipsilateral side, all patients in the RLA group had less than 50% stenosis of ECA at one year after the operation (P=0.021 vs. pre-OP), while in the GA group four patients developed 50-74% stenosis and one patient >75% stenosis of ECA (P<0.001 vs. pre-OP). These results were not significantly different between the two groups and demonstrated a total of 96.7% ECA patency at one year. CONCLUSIONS: Elliptical transsection for EEA enables outstanding ECA revascularization with good patency at one year. Type of anesthesia does not affect the quality of the eversion technique.

External carotid artery stenosis after internal and common carotid stenting.

BACKGROUND: The external carotid artery (ECA) can be an important collateral for cerebral perfusion in the presence of severe internal carotid artery (ICA) disease. ICA stenting that covers the ECA origin may put the ECA at increased risk of stenosis. Our objective was to determine the rate of ECA stenosis secondary to ICA stenting, determine predictive factors, and describe any subsequent associated symptoms. METHODS: We retrospectively reviewed clinical data on all ICA stents crossing the origin of the ECA placed by vascular surgeons at our institution. We analyzed patient demographics, comorbidities, stent type and sizes, as well as medication profile to determine predictors of ECA stenosis. RESULTS: Between 2005 and 2013, there were 72 (out of 119 total ICA stenting) patients (mean age 71, 68% male) who underwent placement of ICA stents that also crossed the origin of the ECA. Six patients (8.3%) had a significantly increased ECA stenosis postprocedure. There were no occlusions. All patients with ECA stenosis maintained patency of their ICA stent and were asymptomatic. Age, gender, comorbidities, stent type and size, and medication profile were not associated with ECA stenosis after stenting. CONCLUSIONS: ECA stenosis after ICA stenting covering the ECA origin is uncommon and not clinically significant in patients with patent ICA stents. The clinical significance of concurrent ECA and ICA stenosis after stenting is unclear as it is not captured here. The potential for ECA stenosis should not deter stenting across the ECA origin if necessary. Patient and stent factors are not predictive of ECA stenosis.

Carotid artery stenting has increased risk of external carotid artery occlusion compared with carotid endarterectomy.

OBJECTIVE: The external carotid artery (ECA) can be an important source of cerebral blood flow in cases of high-grade internal carotid artery stenosis or occlusion. However, the treatment of the ECA is fundamentally different between carotid endarterectomy (CEA) and carotid artery stenting (CAS). CEA is routinely associated with endarterectomy of the ECA, whereas CAS excludes the ECA from direct flow. We hypothesize that these differences make ECA occlusion more common after CAS. Further, the impact of CAS on blood flow into the ECA is interesting because the flow from the stent into the ECA is altered in a way that may promote local inflammation and may influence in-stent restenosis (ISR). Thus, our objective was to use our institutional database to identify whether CAS increased the rate of ECA occlusion and, if it did, whether ECA occlusion was associated with ISR. METHODS: Patients undergoing CAS or CEA from February 2007 to February 2012 were identified from our institutional carotid therapy database. Preoperative and postoperative images of patients who followed up in our institution were included in the analysis of ECA occlusion and rates of ISR. RESULTS: There were 210 (67%) CAS patients and 207 (60%) CEA patients included in this analysis. Despite CAS patients being younger (68 vs 70 years), having shorter follow-up (12.5 vs 56.2 months), and being more likely to take clopidogrel (97% vs 35%), they had an increased rate of ECA occlusion (3.8%) compared with CEA patients (0.4%). CAS patients who went on to ECA occlusion had an increased incidence of prior neck irradiation (50% vs 15%; P = .03), but we did not identify an association of ECA occlusion with ISR >50%. CONCLUSIONS: Whereas prior publications have identified increased rates of external carotid stenosis, this is the first demonstration of increased ECA occlusion after CAS. However, ECA occlusion is uncommon (∼4%) and did not have an association with ISR >50%. Future work modeling ECA flow patterns before and after CAS will be used to further test this interaction.

Cough-induced transient ischemic attack treated with revascularization of the external carotid artery.

A 65-year-old man presented with right arm and face weakness associated with severe coughing fits. A computed tomography angiogram revealed an occlusion of the left common and internal carotid arteries and an incomplete circle of Willis. An arch angiogram demonstrated reconstitution of the left external carotid artery, which collateralized with the intracranial left internal carotid artery. The patient underwent left subclavian-to-external carotid artery bypass with reversed saphenous vein, with complete resolution of symptoms over 1 year of follow-up. Cough-induced hemispheric transient ischemic attack is a rarely described hemodynamic phenomenon that can be managed with revascularization of the external carotid artery in select patients.

Combination of flow reversal and distal filter for cerebral protection during carotid artery stenting.

BACKGROUND: Carotid artery stenting (CAS) with distal filter protection allows continuous cerebral perfusion, although it is associated with a greater risk of cerebral ischemic complications than other protection systems. To reduce cerebral ischemic complications, CAS was performed under combined cerebral protection using both flow reversal (FR) and a distal filter. METHODS: Fifty-six stenoses of 52 patients were treated with CAS using the combined protection of FR and a distal filter, with intermittent occlusion of both the common carotid artery (CCA) and the external carotid artery. The blood flow was reversed into the guiding catheter to the central venous system via an external filter, which collected the debris. Clinical outcomes, the rates of capturing visible debris, and new ischemic signals on diffusion-weighted magnetic resonance imaging (DWI-MRI) were evaluated. RESULTS: The overall technical success rate was 92.9% (52/56). Successful stent deployment was achieved in 100% (56/56) of the cases. No procedural-related emboli causing a neurologic deficit were observed. In 38.5% (20/52) of the cases, visible debris were captured by only the external filter, and in 17.3% (9/52), visible debris were captured by both external and distal filters. In no case was visible debris noted in only the distal filter. New ischemic signals on DWI-MRI were detected in 9.6% (5/52). The 30-day myocardial infarction, stroke, and death rates were 0%. CONCLUSIONS: The additional use of a distal filter captures emboli in 17.3% of cases, and because the occlusion is only intermittent, the procedure is potentially applicable even in those who cannot tolerate prolonged balloon occlusion of the CCA.

A simple technique to achieve bloodless excision of carotid body tumors.

We describe a technique for Shamblin II-III carotid body tumor (CBT) resection to reduce bleeding and neurologic complications during surgery. The technique was based on the fact that CBTs are supplied almost exclusively from the external carotid artery. Therefore, we carefully isolated the origin of the external carotid artery and its distal branches outside the tumor and temporarily clamped all of these vessels after heparin administration. This allowed a safe and bloodless resection as the tumor was dissected from the internal carotid artery in the usual subadventitial plane. The internal carotid artery was never clamped, and respect of peripheral nerves was warranted in the clean and bloodless field. From 2007 to 2010, we treated 11 patients with a CBT: six had a Shamblin II and five had a Shamblin III lesion. Neither perioperative neurologic events nor recurrences occurred after a mean follow-up of 42 months.

Flow velocities in the external carotid artery following carotid revascularization.

OBJECTIVE: To study the changes in peak systolic velocities of the ipsilateral external carotid artery (ECA) following carotid revascularization. METHODS: All patients randomized to carotid artery stenting (CAS) or carotid endarterectomy (CEA) in the International Carotid Stenting Study (ICSS; ISRCTN25337470) in our center were included. Peak systolic velocities (PSV) were assessed with duplex ultrasound (DUS) at baseline, at 30 days, and at 12 and 24 months after treatment. Our primary outcome measure was the change in blood flow velocities in the ECA (ΔPSVECA). Secondary outcome measure was the prevalence of post interventional ECA occlusion. RESULTS: Of 270 patients enrolled in ICSS at our center, 224 patients (mean age, 68.8 years; 154 males) were included in the present study (116 CAS, 108 CEA). Baseline PSV in the ipsilateral ECA was similar between the groups. Following CAS, PSV gradually increased during follow-up, whereas PSV remained relatively stable after CEA; mean difference of PSV between CAS and CEA: 23 cm/s (95% CI, -5 to 52), 58 cm/s (95% CI, 27-89), and 69 cm/s (95% CI, 31-107) at 30 days, 12 months, and 24 months. One new ECA occlusion occurred after CAS and two after CEA. CONCLUSION: Blood flow velocities in the ipsilateral ECA increase significantly after CAS but not after CEA. However, this does not lead to a higher rate of ECA occlusion in the first 2 years after revascularization. We conclude that CAS is not inferior to CEA in preserving the ECA as a possible potential collateral pathway for cerebral blood supply within 2 years following revascularization.

Postoperative changes in the superficial temporal artery and the external carotid artery duplex sonography after extra-intracranial bypass surgery in European Moyamoya disease.

INTRODUCTION: Despite Duplex ultrasonography being a noninvasive, easily repeatable, readily available and economical tool, this examination and its normal ranges are rarely described in Moyamoya disease (MMD). METHODS: Duplex ultrasonography examinations of the superficial temporal artery (STA) and external carotid artery (ECA) were performed preoperatively, postoperatively (within 30 days) and as follow-up exams (6 months postoperatively) after 32 cerebral revascularization procedures in 20 European patients with MMD. RESULTS: A significant higher mean diastolic flow of STA compared to preoperative values was found in postoperative (p<.000) and follow-up exams (p<.001) in Duplex ultrasonography. Postoperative and follow-up Duplex sonography of STA also showed a significantly higher mean systolic flow compared to preoperative values (p<.05 and p<.05). Also ECA showed significantly changes after bypass surgery (p<.05). CONCLUSION: Duplex ultrasonography of STA is a reliable and non-invasive tool to investigate hemodynamic changes after bypass surgery and to detect bypass patency in European patients with MMD.

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.