Validating common carotid stenosis by duplex ultrasound with carotid angiogram or computed tomography scan.

BACKGROUND: No consensus exists for duplex ultrasound criteria in the diagnosis of significant common carotid artery (CCA) stenosis. In general, peak systolic velocity (PSV) >150 cm/s with poststenotic turbulence indicates a stenosis >50%. The purpose of our study is to correlate CCA duplex velocities with angiographic findings of significant stenosis >60%. METHODS: We reviewed the carotid duplex records from 2008 to 2011 looking for patients with isolated CCA stenosis and no ipsilateral internal or contralateral carotid artery disease who received either a carotid angiogram or a computed tomography scan. We identified 25 patients who had significant CCA disease >60%. We also selected 74 controls without known CCA stenosis. We performed receiver operating characteristics analysis to correlate PSV and end-diastolic velocity (EDV) with angiographic stenosis >60%. The degree of stenosis was determined by measuring the luminal stenosis in comparison to the proximal normal CCA diameter. RESULTS: Most patients had a carotid angiogram (21/25), four only had a computed tomography angiography and four had both. Eighteen patients had history of neck radiation. The CCA PSV ≥250 cm/s had a sensitivity of 98.7% (81.5%-100%) and a specificity of 95.7% (92.0%-99.9%), CCA PSV ≥300 cm/s had a sensitivity of 90.9% (69.4%-98.4%) and a specificity of 98.7% (92.0%-99.9%). The CCA EDV ≥40 cm/s had a sensitivity of 95.5% (95% confidence interval of 75.1-99.8%) and specificity of 98.7% (92.0%-99.9%), EDV ≥60 cm/s had a sensitivity of 100% (75.1%-99.8%) and specificity of 87% (94.1-100%), and EDV ≥70 cm/s had a sensitivity of 86.4% (64.0%-96.4%) and specificity of 100% (94.1%-100%). The presence of both PSV <250 cm/s and EDV <60 cm/s had a 98.7% negative predictive value, and the presence of both PSV ≥250 cm/s and EDV ≥60 cm/s had 100% positive predictive value. CONCLUSIONS: Establishing CCA duplex criteria to screen patients with significant stenosis is crucial to identify those who will need further imaging modality or treatment. In our laboratory, CCA PSV ≥250 cm/s and EDV ≥60 cm/s are thresholds that can be used to identify significant (>60%) CCA stenosis with a high degree of accuracy.

A prospective study of a hand-held ultrasound device in abdominal aortic aneurysm evaluation.

PURPOSE: Effective treatment of abdominal aortic aneurysm (AAA) requires both early detection and timely repair to reduce aneurysm-related mortality. The purpose of this prospective study was to evaluate the utility of a hand-held ultrasonography (US) device in AAA screening in a Veterans Affairs vascular surgical service. METHODS: During a 16-month period, patients with risk factors for AAA were evaluated in a blinded fashion with a hand-held US device performed by physicians. A conventional abdominal duplex US examination was also performed by a certified vascular ultrasonographer. Results of the hand-held US was compared with the conventional duplex US examination. RESULTS: A total of 104 patients were evaluated (97 men, mean age 67 +/- 6.3 years). The mean times for hand-held and conventional duplex US examinations were 5.3 +/- 3.2 minutes and 3.1 +/- 2.4 minutes (not significant), respectively. Using the conventional duplex US as a reference, the sensitivity and specificity of the hand-held device in detecting a AAA were 93% and 97%, respectively. The positive and negative predictive values of the hand-held device were 89% and 98%, respectively. The likelihood ratios of positive and negative tests of the hand-held US device examination were 82 and 0.14, respectively. The diagnostic accuracy of the hand-held US device as compared with the conventional duplex US was 98%. CONCLUSIONS: A hand-held portable US device is effective and accurate in AAA screening with results comparable to the conventional abdominal duplex examination. Moreover, hand-held portable US for AAA screening can be performed expeditiously during physical examination. It should be used as an extension in routine physical examination in vascular patients.

Carotid artery stenting with routine cerebral protection in high-risk patients.

BACKGROUND: Carotid artery stenting has emerged as an alternative treatment modality in carotid occlusive disease. This study examined our experience of carotid stenting with routine cerebral embolization protection in high-risk patients. METHODS: Clinical variables and treatment outcome of high-risk patients who underwent carotid stenting with neuroprotection were analyzed during a 26-month period. RESULTS: Sixty-eight high-risk patients with 72 carotid artery stenoses were treated. Procedural success was achieved in 70 cases (97%), and symptomatic lesions existed in 17 (24%) patients. Monorail Wallstents stents were used in all cases. Neuroprotective devices used were PercuSurge (28%) and Filterwire (72%). There was no periprocedural mortality or neuroprotective device-related complications. The 30-day stroke and death rate was 2.7%, and the overall complication rate was 6.9%. All stented vessels remained patent during the follow-up period (mean 15.3 +/- 4.2, range 1 to 23 months). Two asymptomatic in-stent restenosis (3%) occurred at 6 and 8 months, which were both successfully treated with balloon angioplasty. CONCLUSIONS: Our study showed that percutaneous carotid stenting with routine use of a cerebral protection device is a feasible and effective treatment in high-risk patients with carotid occlusive disease.

The impact of anesthetic modality on the outcome of carotid endarterectomy.

BACKGROUND: Carotid endarterectomy (CEA) reduces the risk of stroke in patients with high-grade carotid artery stenosis. This study evaluates the clinical outcome of CEA performed under local anesthesia (LA) versus general anesthesia (GA). METHODS: Clinical variables and treatment outcomes were analyzed in 548 CEAs performed under either LA or GA during a 30-month period. Factors associated with morbidity were also analyzed. RESULTS: A total of 263 CEAs under LA and 285 CEA under GA were analyzed. The LA group was associated with a lower incidence of shunt placement, operative time, and perioperative hemodynamic instability compared to the GA group. No differences in neurologic complications or mortality were found between the 2 groups. Hyperlipidemia was a risk factor for postoperative morbidity in both the LA and GA groups, while age greater than 75 years was associated with increased overall morbidity in the GA group but not the LA group. CONCLUSIONS: This study demonstrates that increased age is associated with increased morbidity in CEA under GA, while hyperlipidemia is associated with increased morbidity in CEA regardless of the anesthetic choice.

Ultrasound criteria for severe in-stent restenosis following carotid artery stenting.

PURPOSE: In-stent restenosis (ISR) is a known complication following carotid artery stenting (CAS). However, ultrasound criteria determining ISR are not well established. We evaluated alternative ultrasound velocity criteria for >70% ISR in our institution. METHODS: Clinical records of 256 patients undergoing 282 consecutive CAS procedures over a 42-month period were reviewed. Follow-up ultrasounds were available for analysis in 237 patients. Selective angiograms and repeat interventions were performed for >70% ISR. Ultrasound criteria including peak systolic velocity (PSV), end diastolic velocity (EDV), and internal carotid to common carotid artery ratios (ICA/CCA) were examined. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for PSV (200, 250, 300, 350, and 400 cm/s), EDV (70, 80, 90, 100 cm/s), and CCA/ICA (3, 3.5, 4, 4.5, 5). RESULTS: Twenty-two carotid angiograms were performed and 18 lesions had confirmations of >70% ISR in 11 patients including prior CEA in five patients and neck irradiation in two patients. Receiver operator characteristics (ROC) was analyzed for PSV, EDV, and CCA/ICA ratio. For 70% or greater angiographic ISR, PSV > 300 cm/s correlated to a 94% sensitivity, 50% specificity, 90% positive predictive value (PPV), and 67% negative predictive value (NPV); EDV > 90 cm/s correlated to an 89% sensitivity, 100% specificity, 100% PPV, and 67% NPV; and ICA/CCA > 4 had a 94.4% sensitivity, 75% specificity, 94% PPV, and 75% NPV. A significant color flow disturbance was detected in one patient who did not meet the aforementioned ultrasound velocity criteria. Further statistical analysis showed that an EDV of 90 cm/s provided the best discriminant value. CONCLUSION: Our study demonstrated that PSV > 300 cm/s, EDV > 90 cm/s, and ICA/CCA > 4 correlated well with >70% ISR. Although still rudimentary, these velocity criteria combined with color flow patterns can reliably predict severe ISR in our vascular laboratory. However, due to the relatively infrequent cases of severe ISR following CAS, a multicentered study is warranted to establish standard post-CAS ultrasound surveillance criteria for severe ISR.

Carotid artery stenting with distal protection using the carotid wallstent and filterwire neuroprotection: single-center experience of 380 cases with midterm outcomes.

Emerging data have supported the clinical efficacy of carotid artery stenting (CAS) in stroke prevention in high-risk surgical patients. This study was performed to evaluate the midterm clinical outcome of CAS using the Carotid Wallstent and FilterWire distal protection (both Boston Scientific, Natick, MA) at an academic institution. Risk factors for in-stent restenosis (ISR) were also analyzed. Clinical variables and treatment outcome of high-risk patients who underwent Carotid Wallstent placement with FilterWire EX/EZ neuroprotection were analyzed during a recent 54-month period. Three hundred eighty CAS procedures were performed in 354 patients. Technical success was achieved in 372 cases (98%), and symptomatic lesions existed in 85 (24%) patients. No patient experienced periprocedural mortality or neuroprotective device-related complication. The 30-day stroke and death rate was 2.7%, and the overall complication rate was 6.9%. The overall major or fatal stroke rates in symptomatic and asymptomatic patients were 4.6% and 1.3%, respectively (not significant). The overall stroke and death rates between the symptomatic and asymptomatic groups were 5.8% and 2.4%, respectively (not significant). The median follow-up period was 29 months (range 1-53 months). With Kaplan-Meier analysis, the rates of freedom from 60% or greater ISR after CAS procedures at 12, 24, 36, and 48 months were 97%, 94%, 92%, and 90%, respectively. The rates of freedom from all fatal and nonfatal strokes at 12, 24, 36, and 48 months were 97%, 91%, 89%, and 85%, respectively. Multivariable analysis of significant univariate predictors identified that postendarterectomy stenosis (odds ratio [OR] 3.98, p = .02) and multiple stent placement (OR 3.68, p = .03) were independent predictors of ISR. Our study yielded favorable short-term and midterm clinical results using Carotid Wallstent with FilterWire neuroprotection. Late follow-up results showed low rates of fatal and nonfatal stroke and favorable ISR rates compared with other carotid stent trials. Postendarterectomy and multiple stent placement were associated with subsequent ISR.

Contrast-enhanced Duplex surveillance after endovascular abdominal aortic aneurysm repair: improved efficacy using a continuous infusion technique.

INTRODUCTION: Currently, postoperative endoleak surveillance after endovascular aortic aneurysm repair (EVAR) is primarily done by computed tomography (CT). The purpose of this study was to determine the efficacy of contrast-enhanced ultrasonography scans to detect endoleaks by using a novel infusion method and compare these findings with those of CT angiography (CTA). METHODS: Twenty male patients (mean age, 70.4 years) underwent surveillance utilizing both CTA and contrast-enhanced color Duplex imaging. One 3-mL vial of Optison (Perfluten Protein A microspheres for injection) and 57 mL normal saline, for a total of 60 mL, were administered to each patient as a continuous infusion at 4 mL/min via a peripheral vein. Each study was optimized with harmonic imaging, and a reduced mechanical index of 0.4 to 0.5, compression of 1 to 3, and a focal zone below the aorta to minimize microsphere rupture. One minute was allowed from the time of infusion to the appearance of contrast in the endograft. Flow was evaluated within the lumen of the graft and its components, as was the presence or absence of endoleaks. Findings were compared with standard color-flow Duplex imaging and CT utilizing CTA reconstruction protocols. RESULTS: All patients evaluated had modular endografts implanted for elective aneurysm repair. Contrast-enhanced duplex scans identified nine endoleaks: one type I and eight type II. No additional endoleaks were seen on CTA. However, CTA failed to recognize three type II endoleaks seen by contrast-enhanced ultrasound. The continuous infusion method allowed for longer and more detailed imaging. An average of 46.8 mL of the contrast infusion solution was used per patient. CONCLUSIONS: Contrast enhanced Duplex ultrasonography accurately demonstrates endoleaks after EVAR and may be considered as a primary surveillance modality. Continuous infusion permits longer imaging time.