Cost-effectiveness of carotid endarterectomy in symptomatic patients.

BACKGROUND: Medical therapy for stroke prevention has improved significantly over the past 30 years. Recent analyses of medically treated cohorts have suggested that early rates of stroke may have reduced, and reports of the safety of carotid surgery have also shown improvements. Since the effectiveness of carotid surgery versus medical therapy was established in the 1990s, there is an urgent need to evaluate whether surgery remains cost-effective in the UK. METHODS: A decision model was developed to estimate the lifetime costs and utilities of modern medical therapy with and without carotid endarterectomy in patients with symptomatic stenosis from the perspective of the UK National Health Service. The base-case population consisted of adults aged 70 years with 70-99 per cent stenosis. Model data were obtained from clinical studies and wider literature. Univariate and probabilistic sensitivity analyses were carried out. RESULTS: In the base-case scenario, the 5-year absolute risk reduction with carotid endarterectomy was 5 per cent, and the incremental cost-effectiveness ratio was €12 021 (exchange rate £1 GBP = €1.1125 (Tuesday 1 January 2019)) per quality-adjusted life-year. Surgery was more cost-effective if performed rapidly after presentation. In patients with 50-69 per cent carotid stenosis, surgery appeared less clinically effective. However, there was considerable uncertainty. CONCLUSION: Surgery may not now be clinically effective and cost-effective in those with moderate carotid stenosis. However, these results are uncertain because of the limited data on modern medical therapy and an RCT may be justified.

Meta-Analysis of Duplex Surveillance Following Lower Limb Endovascular Intervention.

INTRODUCTION: The aim of this systematic review was to identify the evidence in the literature for limb salvage with the introduction of duplex surveillance. METHODS: A systematic review and meta-analysis was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines (PRISMA) methodology for all studies which compared a group undergoing clinical surveillance with a group undergoing combined clinical and duplex surveillance after endovascular therapy for peripheral arterial disease. MEDLINE, EMBASE, the Cochrane Database for Systematic Reviews, and ClinicalTrials.gov were searched for relevant studies by 2 reviewers. Studies were quality assessed using the ROBINS-I tool. An individual patient data survival analysis and meta-analysis for 1- and 2-year amputation outcomes using a random-effects model were performed. RESULTS: Two low-quality nonrandomized studies met the inclusion criteria. There was a statistically and clinically significant reduction in major amputation in patients undergoing combined clinical and duplex surveillance (log-rank p<0.001). The number needed to treat to prevent 1 amputation at 2 years was 5 patients. At 1 year, the odds ratio (OR) for amputation was 0.22, 95% confidence interval (CI)=0.10-0.48, with no statistical heterogeneity. At 2 years, the numbers of patients were low and the effect on amputation was less certain OR=0.25, 95% CI=0.04-1.58. CONCLUSIONS: Preliminary, low-quality data suggests that there may be a clinically significant reduction in major amputation with the introduction of duplex surveillance. It is recommended that a randomized controlled trial is performed to confirm these findings and identify the anatomical subgroups that benefit the most from surveillance. CLINICAL IMPACT: "Two low-quality studies reveal a significant clinical impact: combined clinical and duplex surveillance markedly reduces major amputations (log-rank p<0.001). At 1-year, the odds ratio for amputation is 0.22 (95% CI=0.10-0.48), emphasizing limb salvage benefits. Despite less certainty at 2-years, a notable absolute risk reduction of 19% is seen, with a number needed to treat of 5. This underscores the urgent need for a randomized controlled trial to validate findings and identify key subgroups. The meta-analysis strongly advocates implementing duplex surveillance for a year post-endovascular interventions, especially in patients fit for reintervention, with important considerations for cost-effectiveness and focused clinical trials."

Systematic Review and Meta-Analysis of the Pooled Rate of Post-Thrombotic Syndrome After Isolated Distal Deep Venous Thrombosis.

OBJECTIVE: To identify the rate of post-thrombotic syndrome (PTS) after isolated distal deep venous thrombosis (IDDVT) by performing a meta-analysis of the rate of PTS across randomised and observational studies. DATA SOURCES: MEDLINE, Embase, the Cochrane Controlled Trials Register, Clinicaltrials.gov, European Union Clinical Trials, International Standard Randomised Controlled Trial Number, and the Australian and New-Zealand Trials Registries. REVIEW METHODS: This review followed PRISMA guidelines using a registered protocol (CRD42021282136). Databases were searched up to December 2021 and prospective studies reporting the development of post-thrombotic syndrome were included; these were pooled with the meta-analysis. RESULTS: The results showed a post-thrombotic rate of 17% (95% CI 11 - 26%) (seven studies, 217 cases, 1 105 participants). Heterogeneity was high (I2 = 89%). On meta-regression, the rate of post-thrombotic syndrome was not correlated with the length of follow up (p = .71). Three studies (302 participants) reported the severity of post-thrombotic syndrome: 78% were mild (Villalta score 5 - 9); 11% were moderate (Villalta score 10 - 14), and 11% were severe (Villalta score ≥ 15). CONCLUSION: The risk of post-thrombotic syndrome after IDDVT was one in five and the risk of severe clinical manifestations, including ulceration, was one in 50. There was significant clinical, methodological, and statistical heterogeneity between studies and a substantial risk of bias from pooled studies. Randomised trials to support interventions for prevention of post-thrombotic syndrome are urgently needed.

Systematic review of the use of cyanoacrylate glue in addition to standard wound closure in the prevention of surgical site infection.

Surgical site infection (SSI) is associated with increased morbidity, length of stay, and cost. Cyanoacrylate glue is a low-cost, fluid-proof, antimicrobial barrier. The aim of this systematic review is to assess the use of cyanoacrylate glue after standard wound closure versus dressings in the reduction of SSI. Medline, Embase, Cochrane Library, and clinical trial registries were searched with no restrictions in accordance with PRISMA guidelines. Eligibility criteria were prospective studies comparing glue versus dressings after standardised wound closure. Two reviewers independently screened articles and utilised GRADE for quality assessment. Meta-analysis was not performed because of the heterogeneity of the data. Three articles were included in the review. Study quality was uniformly low. Incidence of SSI was low, between 0% and 4%. No significant differences were reported in the single randomised controlled trial. A single non-randomised parallel group trial reported a significant reduction in the incidence of SSI in the cyanoacrylate group. There was no consistent evidence demonstrating reduction in SSI as a result of the use of cyanoacrylate glue. Future studies should assess the use of cyanoacrylate in procedures with a higher rate of SSI, for example, lower limb bypass.

Antithrombotic Therapy Following Venous Stenting: International Delphi Consensus.

OBJECTIVE/BACKGROUND: Deep venous stenting is increasingly used in the treatment of deep venous obstruction; however, there is currently no consensus regarding post-procedural antithrombotic therapy. The aim of the present study was to determine the most commonly used antithrombotic regimens and facilitate global consensus. METHODS: An electronic survey containing three clinical scenarios on venous stenting for non-thrombotic iliac vein lesions, acute deep vein thrombosis (DVT), and post-thrombotic syndrome was distributed to five societies whose members included vascular surgeons, interventional radiologists, and haematologists. The results of the initial survey (phase 1) were used to produce seven consensus statements, which were distributed to the respondents for evaluation in the second round (phase 2), along with the results of phase 1. Consensus was defined a priori as endorsement or rejection of a statement by ≥ 67% of respondents. RESULTS: Phase 1 was completed by 106 experts, who practiced in 78 venous stenting centres in 28 countries. Sixty-one respondents (58% response rate) completed phase 2. Five of seven statements met the consensus criteria. Anticoagulation was the preferred treatment during the first 6-12 months following venous stenting for a compressive iliac vein lesion. Low molecular weight heparin was the antithrombotic agent of choice during the first 2-6 weeks. Lifelong anticoagulation was recommended after multiple DVTs. Discontinuation of anticoagulation after 6-12 months was advised following venous stenting for a single acute DVT. No agreement was reached regarding the role of long-term antiplatelet therapy. CONCLUSIONS: Consensus existed amongst respondents regarding anticoagulant therapy following venous stenting. At present, there is no consensus regarding the role of antiplatelet agents in this context.

An Inferior Vena Cava Aneurysm in a Patient with Klippel-Trenaunay Syndrome.

Aneurysms of the inferior vena cava (IVC) are rare, with only 54 cases reported in the literature. They carry a significant morbidity and mortality risk. A case of an IVC aneurysm in a patient with Klippel-Trenaunay syndrome (KTS) is reported. Open aneurysmorrhaphy of the type III aneurysm was successfully performed. The patient's leg swelling, back pain, and exercise tolerance improved. IVC aneurysms are not known to be associated with KTS. However, clinicians should have a high index of suspicion for great vessel aneurysms in these patients as they are associated with greater thromboembolic risk.

Simulated Wound Assessment Using Digital Planimetry versus Three-Dimensional Cameras: Implications for Clinical Assessment.

BACKGROUND: Clinical management of wounds can benefit from objective measures of response to treatment. Wound surface area and volume are objective measures of wound healing. Using a synthetic wound model, we compare the accuracy and reproducibility of 2 commercially available 3-dimensional (3D) cameras against planimetry and water displacement. METHODS: Twelve ulcers of various sizes and colors were reproduced in modeling clay and cured. Five naive observers used digital planimetry, water displacement, Eykona camera (Fuel 3D, UK), and Silhouette camera (ARANZ, New Zealand) to measure the wounds. RESULTS: When compared with traditional planimetry, wound surface area measurement with Eykona and Silhouette tended to underestimate wounds by 1.7% and 3.7%, respectively. Spearman correlation coefficients were 0.94 (Eykona) and 0.92 (Silhouette). Intraclass correlations for planimetry and the 2 cameras were all 1. Eykona and Silhouette tended to underestimate wound volumes when compared with water displacement by 58% and 23%, respectively. Spearman correlation coefficients were 0.92 (Eykona) and 0.72 (Silhouette). Intraclass correlations for water displacement and the two cameras were all 1. DISCUSSION: Serial accurate objective area measurements are feasible as part of ongoing clinical assessment of wounds. 3D cameras are reliable but have not shown superior accuracy to manual planimetry, and financial concerns and IT integration may limit general clinical usage. Volume measurements of wounds are practicable as part of clinical care.

Systematic review of perioperative outcomes following laparoscopic abdominal aortic aneurysm repair.

OBJECTIVE: To collate information available in the literature regarding perioperative outcomes following elective laparoscopic abdominal aortic aneurysm repair. MATERIALS AND METHODS: Electronic databases were searched and a systematic review was performed. In total, 1256 abstracts were screened, from which 10 studies were included for analysis. Perioperative and technical outcomes were analysed. RESULTS: In the totally laparoscopic repair of infra-renal aneurysms (n = 302), 30-day mortality ranged between 0% and 6% and in the laparoscopic-assisted cases (n = 547) ranged between 0% and 7%. Of the former group, 5-30% of cases were converted to open repair, with 6% reintervention rate, whereas there was a 5-10% conversion and 3% reintervention rate in the latter group. CONCLUSIONS: The outcomes from selected patients in selected centres demonstrate that elective laparoscopic repair of aortic aneurysms is feasible and comparable in safety to open repair; it remains unclear, however, whether there are substantial advantages of this method compared with open and endovascular repair.

A 2-Stage Approach in Managing Diabetic Forefoot Ulcers.

BACKGROUND: Forefoot plantar ulcers in patients with diabetic neuropathy are considered to be primarily the result of increased shear forces applied over prominent plantar bony prominences. The purpose of this article is to describe a 2-stage treatment pathway utilizing an outpatient percutaneous tendon-Achilles lengthening (TAL) as the first stage procedure and subsequent proximal metatarsal osteotomy (MTO) as a second stage procedure for a persistent or recurrent ulcer. METHODS: A consecutive 112 patients (146 feet), who presented to our Multidisciplinary Diabetic Foot Team clinics since February 2019 with plantar nonischemic forefoot ulcers were included in this study. Excluding the patients who died or were lost to follow-up, 96 feet were followed for a minimum 12 months (range 12-36 months). After TAL, patients were encouraged to walk in a walking cast for 6 weeks and were followed for a minimum 12 months. Patients with persistent or recurrent ulcers were investigated with magnetic resonance imaging scan, and based on intramedullary osteomyelitis and septic destruction of distal metatarsal, we describe a second-stage MTO with the 3 most common clinical presentations. RESULTS: Of 96 feet, none had infection or wound-related problems following TAL. Complete transection of the tendon was noted in 4 patients (4%) and heel callosity in 1 patient. In 92 feet (96%), the ulcers healed within 10 weeks (±4 weeks) after TAL but, in 12 feet (10%), the ulcer failed to heal or recurred. At a minimum 12 months after the second-stage MTO, none in this subgroup had recurrence of ulcer or a transfer lesion. CONCLUSION: TAL followed with a walking cast as an outpatient procedure was effective in healing forefoot ulcers in 96% of feet. Comparable to the widely practiced hand surgery Wide Awake Local Anesthesia No Tourniquet (WALANT) procedure, our approach involved active control of the degree of ankle dorsiflexion by the patient, and the procedure was proven to be safe and well tolerated. When the second-stage MTO was required to offload the forefoot, in our small cohort, patients had ulcer-free outcome for a minimum 12 months. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Dose-dependent artifact in the far wall of the carotid artery at dynamic contrast-enhanced US.

PURPOSE: To quantify a pseudoenhancement phenomenon observed during dynamic contrast material-enhanced ultrasonography (US) of the carotid artery, both in vitro and in vivo. MATERIALS AND METHODS: Ethical approval was obtained prior to commencing this prospective case series, and each patient gave written informed consent. Thirty-one patients with 50%-99% internal carotid artery stenosis underwent dynamic contrast-enhanced US of the carotid bifurcation with use of 2 mL of microbubbles. In the final 10 patients, an additional 1 mL bolus was administered after 15 minutes. Raw linear digital imaging and communications in medicine data were analyzed offline. Regions of interest were drawn within the common carotid artery lumen and immediately adjacent to the lumen in the near and far wall adventitia. Peak intensity was measured. An in vitro experiment with a single-channel flow phantom was also performed. This apparatus consisted of an 8-mm-diameter latex tube placed in a tissue-mimicking fluid. Microbubble concentrations of 0.02%, 0.1%, 0.5%, 1%, and 2% were pumped into the tube. Regions of interest were drawn in a similar fashion to the in vivo experiments, and peak intensity was measured. The Wilcoxon signed rank and paired t tests were used to compare the difference between the near and far wall signal intensities at each dose; a multiplication factor comparing near and far wall signal intensity was derived. RESULTS: The far wall of the common carotid artery was significantly more echogenic than the near wall at 2 mL contrast agent doses (P<.0001, n=31), and the far wall signal intensity increased synchronously with that of the lumen. The difference in signal intensity between near and far wall regions was significantly greater at 2 mL than at 1 mL (P=.012, n=10). In vitro, the phantom tubing demonstrated a similar pattern and magnitude of enhancement to that seen in vivo. CONCLUSION: A dose-dependent, nonlinear propagation artifact known as pseudoenhancement occurs in the far wall adventitia of the carotid artery and should not be mistaken as a marker of plaque vulnerability.

Risk of intracerebral aneurysm rupture during carotid revascularization.

OBJECTIVE: Robust guidelines exist for the treatment of carotid stenosis and intracranial aneurysms independently, however, the management of tandem carotid stenosis and intracranial aneurysms remains uncertain. Although the prevalence of tandem pathologies is small (1.9%-3.2%), treating carotid stenosis can alter intracranial hemodynamics potentially predisposing to aneurysm rupture. In this review, our aim was to assess the safety of intervention in this cohort, by analyzing outcomes from the published literature. METHODS: The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were used to conduct the review. Articles from 1947 to 2012 were searched using EMBASE Classic and EMBASE (November, 1947 -March, 2012) and Ovid MEDLINE(R) In-Process and other NonIndexed Citations and Ovid MEDLINE(R) on Ovid SP, http://ClinicalTrials.gov, http://controlled-trials.com and the Cochrane review database using a predefined search strategy. RESULTS: One hundred forty-one patients from 27 articles were included. Interventions ranged from single (n=104, 74%), staged (n=26, 18%) to simultaneous procedures (n=11, 8%). The largest cohort of patients was treated by carotid endarterectomy alone (n=92, 66%). The majority of patients presented with a symptomatic carotid stenosis and an asymptomatic ipsilateral intracranial aneurysm (n=70, 50%). Five subarachnoid hemorrhages occurred (4% [5/140], three within 30 days of the procedure and two thereafter) of which two were fatal. All five occurred in patients who underwent carotid endarterectomy as a single procedure (5%). Two of the five patients presented with ruptured posterior communicating artery aneurysms. CONCLUSIONS: Published reports of perioperative aneurysm rupture are rare in individuals with tandem carotid stenosis and intracranial aneurysms. This is the first analysis of all published cases. However, it is limited by the small number of studies and the possible underreporting due to publication bias and underdiagnosis where angiography was not performed. Although we report a low incidence of subarachnoid hemorrhage, analysis of registry data with a larger cohort is warranted to confirm these findings.

Periprocedural outcomes after surgical revascularization and stenting for postradiotherapy carotid stenosis.

BACKGROUND: Treatment of head and neck malignancy commonly involves radiotherapy, which is associated with the development of carotid artery stenosis. There is little evidence to guide clinicians on how to intervene in significant postradiotherapy carotid stenosis. This systematic review collated data pertaining to perioperative outcomes of carotid artery surgery and carotid stenting in postradiotherapy carotid stenosis to aid the clinical decision-making process. METHODS: A systematic review of the literature, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 guidelines, was performed. We screened 575 articles related to carotid artery surgery or stenting in postradiotherapy carotid stenosis, from which 21 studies were included for quantitative analysis. The primary outcome was stroke or death ≤ 30 days of the procedure. Secondary outcomes included cranial nerve injury, restenosis, stroke, and death at >30 days. RESULTS: Nine publications recorded 211 surgical procedures in 179 patients. In symptomatic patients, the 30-day mortality rate was 2.6% and the stroke or death rate was 2.7%. In asymptomatic patients, the 30-day mortality rate was 0% and the stroke or death rate was 1.1%. Permanent cranial nerve palsy was experienced by 0.6% of patients. Twelve publications recorded 510 carotid artery stenting procedures in 482 patients. In symptomatic patients, the 30-day mortality rate was 5.1%, and the stroke or death rate was 5.1%. In asymptomatic patients, the 30-day mortality rate was 1.4%, and the stroke or death rate was 2.1%. There was no statistically significant difference in 30-day stroke or death rate between surgical revascularization and carotid artery stenting in all (odds ratio [OR], 0.54; 95% confidence interval [CI] 0.17-1.70; P = .43), symptomatic (OR, 0.52; 95% CI, 0.14-1.98; P = .38), or asymptomatic patients (OR, 0.55; 95% CI, 0.06-5.42; P = .99). CONCLUSIONS: The published outcomes from high-volume centers demonstrate that surgical revascularization and stenting are both technically feasible in postradiotherapy carotid stenosis and have similar safety profiles to nonirradiated necks. Radiation should therefore not be considered a contraindication to surgical intervention.

Total endoluminal repair of aorto-oesophageal fistula.

A woman in her 50s presented to the Emergency Department, following massive haematemesis, having swallowed a single tooth denture 3 years previously. Endoscopy initially revealed profuse bleeding at 20cm from the incisors, initially treated with an oesophageal covered stent. Following ongoing haematemesis, a thoracic and abdominal CT angiogram demonstrated an aorto-oesophageal fistula, which was successfully treated with a thoracic endograft and left tube thoracostomy. The patient remains well to 1 year. This is the first case to demonstrate successful use of covered stents in both the aorta to stop exsanguination, as well as the oesophagus to prevent mediastinitis and avoid the need for thoracotomy and hypothermic circulatory arrest in a critically ill patient.

Thyroid Hemiagenesis: Narrative Review and Clinical Implications.

Thyroid Hemiagenesis (THA) is an uncommon, congenital anomaly defined by the absence of one thyroid lobe with or without the isthmus. Reports suggest it may be found more often in regions endemic for hypothyroidism. Genetic abnormalities are thought to have a role based on findings in monozygotic twins. Most cases are sporadic, however familiar clusters have also been documented. It is found more frequently in females. A majority of patients report no symptoms and THA is found incidentally during investigations or intraoperatively. THA is usually associated with normal thyroid function, but it can present with thyroid hypofunction. Since a majority of patients are asymptomatic, there are no specific recommendations for management. Ultrasound imaging and thyroid scintigraphy using technetium or iodine are useful in diagnosis. Its clinical importance occurs when the remnant thyroid lobe requires excision leading to the lifelong requirement for thyroxine supplementation. Published English literature (Medline, PubMed, and Embase databases) was searched. Medical subject headings (MeSH) terms used were "thyroid hemiagenesis," "one thyroid lobe," and "thyroid aplasia". Case reports, case series, and original articles were selected to provide a framework for this review. Articles reviewed were published in the past 20 years. The association of THA with thyroid cancer was explored. In this group, the F:M ratio was 3.25:1. Left THA constituted 53% of cases, right THA in 29.4%, and isthmus absence in 17.6% of cases. Also, the authors investigated the link between THA and hyperparathyroidism, both left and right THA are seen in an equal number of cases in the hyperparathyroidism subgroup. In patients with THA and Grave's disease, left THA was seen in a majority of cases (86.7%), while an equal number of left and right THA was observed in patients with Hashimoto's thyroiditis. In addition, congenital abnormalities associated with THA were observed, the left THA was seen in 60% and right THA in 40% of cases of this subgroup. The summative review provided a detailed insight into the epidemiology, aetiopathogenesis, genetics, symptomatology, diagnosis, and treatment for THA by combining findings and results from almost a hundred research papers from around the world. THA remains a poorly understood, often incidentally detected, abnormality in euthyroid patients undergoing investigations and treatment for other thyroid disorders.

Late-phase contrast-enhanced ultrasound reflects biological features of instability in human carotid atherosclerosis.

BACKGROUND AND PURPOSE: Development of translational functional imaging modalities for atherosclerosis risk stratification is sought for stroke prediction. Our group has developed late-phase contrast-enhanced ultrasound (LP-CEUS) to quantify microbubble contrast retention within carotid atherosclerosis and shown it to separate asymptomatic plaques from those responsible for recent cerebrovascular events. We hypothesized that microbubbles are retained in areas of plaque inflammation, aiming to examine whether LP-CEUS signal reflects plaque biology. METHODS: Subjects awaiting carotid endarterectomy (n=31) underwent axial LP-CEUS and diseased intimal segments were symmetrically divided in the long axis. Half-specimens underwent quantitative immunohistochemical analysis for CD68 (macrophages) and CD31 (angiogenesis). Half-specimens were processed for atheroma cell culture and supernatant collected at 24 hours for multianalyte profiling for 34 analytes. RESULTS: Percentage area immunopositivity was significantly higher in subjects in which normalized plaque late-phase intensity was ≥0 versus <0 (CD68 mean 11.8 versus 6.68, P=0.004; CD31 mean 9.45 versus 4.82, P=0.025). Interleukin-6, matrix metalloproteinase-1, and matrix metalloproteinase-3 were significantly higher by multianalyte profiling when LP-CEUS was ≥0. CONCLUSIONS: LP-CEUS reflects biological features of inflammation and angiogenesis, key features predisposing to plaque rupture. Further investigation of LP-CEUS as a tissue-specific marker of inflammation for risk stratification of carotid atherosclerosis is warranted.

Silent cerebral events in asymptomatic carotid stenosis.

BACKGROUND: Approximately 20% of strokes are attributable to carotid stenosis. However, the number of asymptomatic patients needed to prevent one stroke or death with endarterectomy is high at 17 to 32. There is a clear need to identify asymptomatic individuals at high risk of developing future ischemic events to improve the cost-effectiveness of surgery. Our aim was to examine the evidence for subclinical microembolization and silent brain infarction in the prediction of stroke in asymptomatic carotid stenosis using transcranial Doppler (TCD), computed tomography (CT), and magnetic resonance imaging (MRI). METHODS: The review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Articles regarding humans between 1966 and 2010 were identified through systematic searches of Pubmed, MEDLINE, and EMBASE electronic databases using a predetermined search algorithm. RESULTS: Fifty-eight full text articles met the inclusion criteria. A median of 28% of microemboli positive patients experienced a stroke or transient ischemic attack during follow-up compared with 2% of microemboli negative patients (P = .001). The same was true for the end point of stroke alone with a median of 10% of microemboli positive patients experiencing a stroke vs 1% of microemboli negative patients (P = .004). A specific pattern of silent CT infarctions was related to future stroke risk (odds ratio [OR] = 4.6; confidence interval [CI] = 3.0-7.2; P < .0001). There are no prospective MRI studies linking silent infarction and stroke risk. CONCLUSIONS: There is level 1 evidence for the use of TCD to detect microembolization as a risk stratification tool. However, this technique requires further investigation as a stroke prevention tool and would be complemented by improvements in carotid plaque imaging.