Stavros K. Kakkos

Asymptomatic internal carotid artery stenosis and cerebrovascular risk stratification

BACKGROUND The purpose of this study was to determine the cerebrovascular risk stratification potential of baseline degree of stenosis, clinical features, and ultrasonic plaque characteristics in patients with asymptomatic internal carotid artery (ICA) stenosis. METHODS This was a prospective, multicenter, cohort study of patients undergoing medical intervention for vascular disease. Hazard ratios for ICA stenosis, clinical features, and plaque texture features associated with ipsilateral cerebrovascular or retinal ischemic (CORI) events were calculated using proportional hazards models. RESULTS A total of 1121 patients with 50% to 99% asymptomatic ICA stenosis in relation to the bulb (European Carotid Surgery Trial [ECST] method) were followed-up for 6 to 96 months (mean, 48). A total of 130 ipsilateral CORI events occurred. Severity of stenosis, age, systolic blood pressure, increased serum creatinine, smoking history of more than 10 pack-years, history of contralateral transient ischemic attacks (TIAs) or stroke, low grayscale median (GSM), increased plaque area, plaque types 1, 2, and 3, and the presence of discrete white areas (DWAs) without acoustic shadowing were associated with increased risk. Receiver operating characteristic (ROC) curves were constructed for predicted risk versus observed CORI events as a measure of model validity. The areas under the ROC curves for a model of stenosis alone, a model of stenosis combined with clinical features and a model of stenosis combined with clinical, and plaque features were 0.59 (95% confidence interval [CI] 0.54-0.64), 0.66 (0.62-0.72), and 0.82 (0.78-0.86), respectively. In the last model, stenosis, history of contralateral TIAs or stroke, GSM, plaque area, and DWAs were independent predictors of ipsilateral CORI events. Combinations of these could stratify patients into different levels of risk for ipsilateral CORI and stroke, with predicted risk close to observed risk. Of the 923 patients with ≥ 70% stenosis, the predicted cumulative 5-year stroke rate was <5% in 495, 5% to 9.9% in 202, 10% to 19.9% in 142, and ≥ 20% in 84 patients. CONCLUSION Cerebrovascular risk stratification is possible using a combination of clinical and ultrasonic plaque features. These findings need to be validated in additional prospective studies of patients receiving optimal medical intervention alone.

Validation of the new venous severity scoring system in varicose vein surgery

OBJECTIVES We performed this observational study to validate the three components of a new venous severity scoring (VSS) system, ie, venous clinical severity score (VCSS), venous segmental disease score (VSDS), and venous disability score (VDS), and to evaluate VCSS, VDS, and CEAP clinical class and score in quantifying outcome of varicose vein surgery. Patients and methods The study included 45 patients who underwent superficial venous surgery in 48 legs with primary varicose veins. Venous color duplex scanning, clinical examination, and a questionnaire were used preoperatively and at 6 weeks and 6 months postoperatively to assign VSS and CEAP clinical class and score. RESULTS CEAP clinical score, VCSS, and VDS demonstrated a linear association with CEAP clinical class (P <.001, P <.001, P =.002, respectively). Good correlation among all severity scores was found, particularly between CEAP clinical score and VCSS (r = 0.94; P <.001). CEAP clinical score was also highly correlated with CEAP clinical class (r = 0.84; P <.001) and VDS (r = 0.70; P <.001). Similarly, VCSS correlated with CEAP clinical class (r = 0.83; P <.001) and also VDS (r = 0.72; P <.001). The anatomic severity marker VSDS demonstrated a weak correlation with clinical severity indicators VCSS (r = 0.29; P =.048) and VDS (r = 0.31; P =.03) but not with age, gender, or CEAP clinical class and score. Six months after surgery the median (interquartile range) percent change in VCSS (73%; range, 50%-100%) and CEAP clinical score (70%; range, 50%-100%) were both significantly greater (P <.001) than the corresponding change in CEAP clinical class (17%; range, 0%-50%). In legs with high VDS at baseline, median (interquartile range) percent change in VDS was 100% (range, 50%-100%), significantly greater (P <.001) than the corresponding change in CEAP clinical class (0%; range, 0%-17%). CONCLUSIONS Venous severity scores are significantly higher in advanced venous disease, demonstrating correlation with anatomic extent. Both venous clinical severity scores, VCSS and CEAP clinical score, are equally sensitive and significantly better for measuring changes in response to superficial venous surgery than is the already in use CEAP clinical class. VDS demonstrated comparable and even better performance. Although the assignment of CEAP clinical class might be adequate for daily clinical purposes, venous severity scoring systems should be used in clinical studies to quantify venous outcome.

Relative risk of cancer in sonographically detected thyroid nodules with calcifications.

The aim of this prospective study was to evaluate the significance of sonographically detected thyroid calcifications in the diagnosis of thyroid cancer.

Delayed presentation of aortic injury by pedicle screws: Report of two cases and review of the literature

OBJECTIVES Perforation of the aorta by pedicle screws is a rare but serious complication of spine fixation surgery. This article reviews the clinical presentation and management of this complication. METHODS Presented are two cases of thoracic aorta perforation by a pedicle screw and a review of the appropriate literature performed using a MEDLINE search. RESULTS Literature review identified eight additional patients. In most cases, aortic perforation was recognized and managed within 18 months of the spine surgery. Clinical presentation included acute bleeding, necessitating urgent exploration in two patients, and pseudoaneurysm formation in five cases, two of which were infected. Depending on the extent of aortic damage and the presence or absence of infection, management ranged from endovascular grafting, to screw burring with closure of the perforation site, to aortic reconstruction with a tube graft and complete orthopedic hardware removal. Outcome was favorable in all patients who were operated on. CONCLUSIONS The small number of reported cases indicates either the rarity of this complication or unawareness of its existence. The true incidence of this complication is probably under-reported. Orthopedic and vascular surgeons should be aware of this potentially fatal problem. Prevention remains the best treatment. Once encountered, a variety of techniques are available to manage this complication with reasonable outcome.

Silent embolic infarcts on computed tomography brain scans and risk of ipsilateral hemispheric events in patients with asymptomatic internal carotid artery stenosis

OBJECTIVES This study tested the hypothesis that silent embolic infarcts on computed tomography (CT) brain scans can predict ipsilateral neurologic hemispheric events and stroke in patients with asymptomatic internal carotid artery stenosis. METHODS In a prospective multicenter natural history study, 821 patients with asymptomatic carotid stenosis graded with duplex scanning who had CT brain scans were monitored every 6 months for a maximum of 8 years. Duplex scans were reported centrally, and stenosis was expressed as a percentage in relation to the normal distal internal carotid criteria used by the North American Symptomatic Carotid Endarterectomy Trialists. CT brain scans were reported centrally by a neuroradiologist. In 146 patients (17.8%), 8 large cortical, 15 small cortical, 72 discrete subcortical, and 51 basal ganglia ipsilateral infarcts were present; these were considered likely to be embolic and were classified as such. Other infarct types, lacunes (n = 15), watershed (n = 9), and the presence of diffuse white matter changes (n = 95) were not considered to be embolic. RESULTS During a mean follow-up of 44.6 months (range, 6 months-8 years), 102 ipsilateral hemispheric neurologic events (amaurosis fugax in 16, 38 transient ischemic attacks [TIAs], and 47 strokes) occurred, 138 patients died, and 24 were lost to follow-up. In 462 patients with 60% to 99% stenosis, the cumulative event-free rate at 8 years was 0.81 (2.4% annual event rate) when embolic infarcts were absent and 0.63 (4.6% annual event rate) when present (log-rank P = .032). In 359 patients with <60% stenosis, embolic infarcts were not associated with increased risk (log-rank P = .65). In patients with 60% to 99% stenosis, the cumulative stroke-free rate was 0.92 (1.0% annual stroke rate) when embolic infarcts were absent and 0.71 (3.6% annual stroke rate) when present (log-rank P = .002). In the subgroup of 216 with moderate 60% to 79% stenosis, the cumulative TIA or stroke-free rate in the absence and presence of embolic infarcts was 0.90 (1.3% annual rate) and 0.65 (4.4% annual rate), respectively (log-rank P = .005). CONCLUSION The presence of silent embolic infarcts can identify a high-risk group for ipsilateral hemispheric neurologic events and stroke and may prove useful in the management of patients with moderate asymptomatic carotid stenosis.

Effect of Image Normalization on Carotid Plaque Classification and the Risk of Ipsilateral Hemispheric Ischemic Events: Results from the Asymptomatic Carotid Stenosis and Risk of Stroke Study:

The aim of this study was to determine the effect of image normalization on plaque classification and the risk of ipsilateral ischemic neurologic events in patients with asymptomatic carotid stenosis. The first 1,115 patients recruited to the Asymptomatic Carotid Stenosis and Risk of Stroke (ACSRS) study with a follow-up of 6 to 84 months (mean 37.1 months) were included in this study. Duplex ultrasonography was used for grading the degree of internal carotid artery stenosis and for plaque characterization (types 1–5), which was performed before and after image normalization. One hundred sixteen ipsilateral ischemic hemispheric events occurred. Image normalization resulted in 60% of plaques being reclassified. Before image normalization, a high event rate was associated with all types of plaque. After image normalization, 109 (94%) of the events occurred in patients with plaque types 1 to 3. For patients with European Carotid Stenosis Trial (ECST) 70 to 99% diameter stenosis (equivalent to North American Symptomatic Carotid Endarterectomy Trial [NASCET] 50–99%) with plaque types 1 to 3, the cumulative stroke rate was 14% at 7 years (2% per year), and for patients with plaque types 4 and 5, the cumulative stroke rate was 0.9% at 7 years (0.14% per year). The results suggest that asymptomatic patients with plaque types 4 and 5 classified as such after image normalization are at low risk irrespective of the degree of stenosis.

Primary Everolimus-Eluting Stenting Versus Balloon Angioplasty With Bailout Bare Metal Stenting of Long Infrapopliteal Lesions for Treatment of Critical Limb Ischemia

Purpose: To report the long-term outcomes of a single-center prospective study investigating primary placement of everolimus-eluting metal stents for recanalization of long infrapopliteal lesions compared to a matched historical control group treated with plain balloon angioplasty and provisional placement of bare metal stents in a bailout manner. Methods: The study included 81 patients (63 men; mean age 71 years, range 45–85) suffering from critical limb ischemia (CLI) and angiographically proven long-segment (at least 1 lesion >4.5 cm) de novo infrapopliteal artery disease who underwent below-the-knee revascularization with either primary placement of everolimus-eluting stents (n = 47, 51 limbs, 102 lesions) or angioplasty and bailout bare metal stenting (n=34, 36 limbs, 72 lesions). Clinical and angiographic follow-up was collected at regular time intervals. Primary clinical and angiographic endpoints included patient survival, major amputationfree survival, angiographic primary patency, angiographic binary restenosis (>50%), and overall event-free survival. Results were stratified according to endovascular treatment received. Multivariable Cox proportional hazards regression analysis was applied to adjust for confounding factors of heterogeneity. Results: Baseline demographics were well matched. No significant differences were identified between the 2 groups with regard to overall 3-year patient survival (82.2% versus 65.7%; p=0.90) and amputation-free survival (77.1% versus 86.9%; p=0.20). Up to 3 years, lesions fully covered with everolimus-eluting stents were associated with significantly higher primary patency [hazard ratio (HR) 7.98, 95% CI 3.69 to 17.25, p<0.0001], reduced binary restenosis (HR 2.94, 95% CI 1.74 to 4.99, p<0.0001), and improved overall event-free survival (HR 2.19, 95% CI 1.16 to 4.13, p=0.015) versus the matched historical control group. Conclusion: Primary infrapopliteal everolimus-eluting stenting for CLI treatment significantly inhibits restenosis and improves long-term angiographic patency and overall patient event-free survival compared to balloon angioplasty and bailout bare metal stenting.

A Review of Noninvasive Ultrasound Image Processing Methods in the Analysis of Carotid Plaque Morphology for the Assessment of Stroke Risk

Noninvasive ultrasound imaging of carotid plaques allows for the development of plaque-image analysis methods associated with the risk of stroke. This paper presents several plaque-image analysis methods that have been developed over the past years. The paper begins with a review of clinical methods for visual classification that have led to standardized methods for image acquisition, describes methods for image segmentation and denoizing, and provides an overview of the several texture-feature extraction and classification methods that have been applied. We provide a summary of emerging trends in 3-D imaging methods and plaque-motion analysis. Finally, we provide a discussion of the emerging trends and future directions in our concluding remarks.

Editor's Choice – Management of Descending Thoracic Aorta Diseases : Clinical Practice Guidelines of the European Society for Vascular Surgery (ESVS)

Editors Choice - Management of Descending Thoracic Aorta Diseases : Clinical Practice Guidelines of the European Society for Vascular Surgery (ESVS).

Predictors and clinical significance of progression or regression of asymptomatic carotid stenosis

OBJECTIVE To determine baseline clinical and ultrasonographic plaque factors predictive of progression or regression of asymptomatic carotid stenosis and the predictive value of changes in stenosis severity on risk of first ipsilateral cerebral or retinal ischemic events (including stroke). METHODS A total of 1121 patients with asymptomatic carotid stenosis of 50% to 99% in relation to the bulb diameter (European Carotid Surgery Trial [ECST] method) underwent six monthly clinical assessments and carotid duplexes for up to 8 years (mean follow-up, 4 years). Progression or regression was considered present if there was a change of at least one grade higher or lower, respectively, persisting for at least two consecutive examinations. RESULTS Regression occurred in 43 (3.8%), no change in 856 (76.4%), and progression in 222 (19.8%) patients. Younger age, high grades of stenosis, absence of discrete white areas in the plaque, and taking lipid lowering therapy were independent baseline predictors of increased incidence of regression. High serum creatinine, male gender, not taking lipid lowering therapy, low grades of stenosis, and increased plaque area were independent baseline predictors of progression. One hundred and thirty first ipsilateral cerebral or retinal ischemic events, including 59 strokes, occurred. Forty (67.8%) of the strokes occurred in patients whose stenosis was unchanged, 19 (32.2%) in those with progression, and zero in those with regression. For the entire cohort, the 8-year cumulative ipsilateral cerebral ischemic stroke rate was zero in patients with regression, 9% if the stenosis was unchanged, and 16% if there was progression (average annual stroke rates of 0%, 1.1%, and 2.0%, respectively; log-rank, P = .05; relative risk in patients with progression, 1.92; 95% confidence interval, 1.14-3.25). For patients with baseline stenosis 70% to 99% in relation to the distal internal carotid (North American Symptomatic Carotid Endarterectomy Trial [NASCET] method), in the absence of progression (n = 349), the 8-year cumulative ipsilateral cerebral ischemic stroke rate was 12%. In the presence of progression (n = 77), it was 21% (average annual stroke rates of 1.5% and 2.6%, respectively; log-rank, P = .34). Only nine (30%) of the 30 strokes occurred in the progression group. CONCLUSIONS Progressive asymptomatic carotid stenosis identified a subgroup with about twice the risk of ipsilateral stroke compared with those without progression. However, the clinical value of screening for progression simply for selecting patients for carotid procedures is limited because of the low frequency of progression and its relatively low associated stroke rate. The cost effectiveness of screening for change in stenosis severity to better direct current optimal medical treatment needs testing.