Pseudo-tandem stenosis of the internal carotid artery

Two cases of pseudo-tandem stenosis of the internal carotid artery are presented. Proximal stenosis was produced by a large, focal atherosclerotic plaque. The severe intracranial "stenosis" was thought to be an angiographic artifact. Repeat cerebral angiography after carotid endarterectomy revealed normal intracranial arteries. The recognition of this entity is important because a decision to operate is based largely upon angiographic findings.     

Combined carotid endarterectomy and coronary artery bypass grafting in asymptomatic carotid artery stenosis

The role of combined carotid endarterectomy (CEA) and coronary artery bypass grafting (CABG) in patients with severe asymptomatic carotid artery disease and concurrent symptomatic coronary artery disease is controversial. The objective of this report is to investigate the safety of combined CEA/CABG. The medical records of 30 patients who underwent combined CEA/CABG for coexistent asymptomatic carotid and symptomatic coronary artery occlusive disease were reviewed. All patients were scheduled for either elective or urgent myocardial revascularization due to their symptomatic coronary artery disease. Color-flow duplex scanning identified internal carotid artery stenosis of 80 to 99 per cent in 28 patients (93%) and 50 to 79 per cent in 2 patients (7%). Seventeen patients (57%) were male. The mean age was 64 +/- 10 years (range, 42-84 years). Contralateral internal carotid artery occlusion was present in four patients. Severe left main coronary artery disease was present in 12 patients (40%) and 7 patients (23%) had an ejection fraction of less than 50 per cent. There were no perioperative deaths or strokes. One patient suffered a myocardial infarction on postoperative day 1. This study demonstrates the safety of combined CEA/CABG for coexistent coronary and asymptomatic carotid disease. Using this surgical approach for critical coexistent disease may minimize the incidence of perioperative cerebrovascular complications in patients undergoing CABG.     

How does carotid artery stenosis increase?

In 25 patients with carotid artery stenosis equal or higher than 40% colour doppler examinations were performed 105 times. The aim of this study was estimate the dynamics of progress of carotid artery stenosis. The mean time of observation was 22.5 months. In 11 (44%) patients there was no progress of stenosis, in 6 (24%) a leap progress over 30% of arterial lumen, and in 8 (32%) patients the progress of carotid artery stenosis were gradual and slow. The leap progress of carotid artery stenosis was usually caused by eruption or dissection of atherosclerotic plaque located in carotid bifurcation and this situation poses especially high risk of stroke.     

Prediction of cure of hypertension in atherosclerotic renal artery stenosis

We analysed the outcome of 63 consecutive, adequate interventions for atherosclerotic renal artery stenosis and hypertension: 34 patients had percutaneous transluminal renal angioplasty, and 29 had surgical correction. Hypertension was cured in 21% of patients and improved in 47%, but 32% failed to respond. We analyzed clinical variables predictive of cure. Duration of hypertension, level of diastolic blood pressure, and sex were found to be predictive of cure. The highest probability of cure was found in men with a duration of hypertension of less than 10 years and an initial diastolic blood pressure of greater than 80 mm Hg. Use of these clinical variables in a tree-based model correctly classified 80% of cases, with a sensitivity of 92% and a specificity of 77%. We conclude that a tree-based clinical algorithm based on only three clinical criteria correctly predicted cure of hypertension in most patients with renal artery stenosis and may be useful in decision making. A prospective analysis will be required to evaluate the clinical validity of the algorithm.     

Impaired dynamic cerebral autoregulation in carotid artery stenosis

BACKGROUND AND PURPOSE: If it could be determined whether cerebral blood flow can be maintained (autoregulated) during transient falls in arterial blood pressure, we might be able to identify patients with carotid stenosis who are at risk of stroke. However, conventional methods of determining autoregulation in such patients are invasive and/or expensive. METHODS: We used a new noninvasive method to estimate dynamic cerebral autoregulation in 27 patients with carotid stenosis and 21 age-matched normal controls. After a stepwise fall in arterial blood pressure, we determined the rate of rise of middle cerebral artery blood flow velocity compared with that of arterial blood pressure. We compared the method with a conventional method of determining cerebral hemodynamics, CO2 reactivity. RESULTS: Autoregulatory index (ARI) was significantly reduced in middle cerebral arteries ipsilateral to a stenosed/ occluded carotid artery: mean +/- SD 3.3 +/- 2.2 compared with normal controls (6.3 +/- 1.1; P < .0001) and nonstenosed carotid arteries in patients (5.9 +/- 2.1; P < .002). A subgroup of patients with severe impairment was identified. ARI returned to normal after carotid endarterectomy was performed. In a number of cases, ARI was impaired in the presence of CO2 reactivity. CONCLUSIONS: This simple technique allows identification of impaired autoregulation in patients with carotid artery disease. It may allow identification of patients at risk from transient falls of blood pressure as may occur at the onset of antihypertensive therapy and during surgery. It may allow a subgroup of patients with asymptomatic carotid stenosis who are at risk of hemodynamic stroke to be identified.     

Stenting of symptomatic stenosis of the intracranial internal carotid artery

Sarcoidosis presenting solely as a granulomatous colitis is rare and appears identical to Crohn's disease. A 56-yr-old woman developed a Crohn's-like illness, which remitted after 5-ASA therapy. Two months later, she developed fever, adenopathy, muscle weakness, and peripheral neuropathy. A diagnosis of sarcoidosis was made after an extensive search for an infectious or rheumatological cause. This case illustrates the utility of serum angiotensin converting enzyme level in differentiating sarcoidosis from Crohn's disease.     

Elective stenting of carotid artery stenosis in patients with severe coronary artery disease

AIMS: To evaluate the feasibility and safety of elective carotid stent implantation in patients with carotid stenoses and concomitant coronary artery disease, as an alternative to combined carotid and coronary surgery. METHODS: We treated 50 patients with >70%, stenoses in 53 carotid arteries with balloon angioplasty followed by elective stent implantation. All patients had severe coronary artery disease, and/or mitral insufficiency, aortic stenosis, rhythm disorders or generalized arteriosclerosis. In three patients the opposite carotid artery was occluded; nine patients had bilateral stenoses of which two received stents bilaterally. RESULTS: Fifty-six successful stent implantations (42 Wallstents, eight BeStents, two AVE-Microstents, one Palmaz Schatz stent, three Sito stents) were performed, reducing the baseline percent stenosis from 78 +/- 18%, to 13 +/- 11%. Complications included three transient ischaemic attacks, one minor and one major stroke. Follow-up was available for 46 patients over a mean of 10 months. Three asymptomatic restenoses and one deformation of a BeStent occurred. CONCLUSION: Our preliminary results indicate that carotid artery stenting in patients with concomitant severe coronary artery disease is feasible, safe, and may be an alternative to combined carotid and coronary surgery.     

Outcome of moderate carotid artery stenosis in patients who are asymptomatic

PURPOSE: The incidence rate of disease progression and stroke after the diagnosis of a moderate (50% to 79%) carotid stenosis was determined by means of color-flow duplex scanning. METHODS: During a 4-year period, 344 male veterans with moderate internal carotid artery stenoses, on one or both sides, were examined at regular intervals for a mean period of 25 months. Carotid color-flow scans were obtained semiannually. Clinical follow-up was performed to determine the incidence rate of amaurosis fugax, transient ischemic attacks, nonhemispheric symptoms, and strokes. RESULTS: New neurologic symptoms developed in 75 patients (21.8%). Fifty-one (14.8%) had ipsilateral symptoms during follow-up: 18 amaurosis fugax (5.2%), 14 transient ischemic attacks (4%), 5 nonhemispheric symptoms (1.4%), and 14 strokes (4%). Twenty-four patients (6.9%) had contralateral symptoms: 20 strokes (5.8%) and 4 transient ischemic attacks (1.2%). Life-table analysis showed that the annual rate of ipsilateral neurologic events was 8.1%, and the annual rate of stroke was 2.1%. Seventy-five patients (22%) died in the follow-up period. Disease progression to 80% to 99% stenosis or occlusion occurred in 71 of 458 vessels (15.5%). The internal carotid arteries that showed evidence of disease progression had a significantly higher initial peak systolic velocity (251 vs 190 cm/s; P <.0001) and end diastolic velocity (74 vs 52 cm/s; P < 0.0001). Black patients and patients with ischemic heart disease were at a higher risk for disease progression. We could not identify any atherosclerotic risk factors that reliably predicted patients in whom future ipsilateral neurologic symptoms were more likely to develop. However, there was an increased risk of stroke associated with progression of disease. CONCLUSION: Patients who are asymptomatic and who have moderate carotid stenoses are at significant risk for neurologic symptoms and death, but have a relatively low incidence rate of ipsilateral events. The initial flow characteristics in the stenotic vessel are predictive of future disease progression, but they are not helpful in identifying patients in whom symptoms will develop.     

A prospective study of disease progression in patients with atherosclerotic renal artery stenosis

The natural history of renal artery stenosis (RAS) has been difficult to document because serial arteriography is rarely justified. Duplex scanning is a noninvasive technique that is ideally suited for both screening and follow-up of RAS. In this approach, renal arteries are classified as normal, < 60% stenosis, > or = 60% stenosis, or occluded, and disease progression is defined as a change in the duplex classification. The purpose of this study was to determine the rate of disease progression in atherosclerotic RAS by serial duplex scanning. At least one abnormal renal artery was identified in each of 76 patients being screened for RAS. Of the 152 renal arteries, 20 were excluded (14 prior interventions, 5 occlusions, 1 technically inadequate duplex scan), leaving 132 for the natural history follow-up protocol. The patient group included 36 men and 40 women, with a mean age of 67 years, who were followed for a mean of 32 months (maximum 55 months). The initial status of the 132 renal arteries was normal in 36, < 60% stenosis in 35, and > or = 60% stenosis in 61. The cumulative incidence of progression from normal to > or = 60% RAS was 0% at 1 year, 0% at 2 years, and 8% at 3 years. The cumulative incidence of progression from < 60% to > or = 60% RAS was 30% at 1 year, 44% at 2 years, and 48% at 3 years. All 4 renal arteries that progressed to occlusion had > or = 60% stenoses at the initial visit, and for those arteries with a > or = 60% stenosis, the cumulative incidence of progression to occlusion was 4% at 1 year, 4% at 2 years, and 7% at 3 years. Progression of RAS occurred at an average rate of 7% per year for all categories of baseline disease combined. Progression of atherosclerotic RAS is relatively common, particularly from < 60% to > or = 60% stenosis.     

Four-year follow-up of Palmaz-Schatz stent revascularization as treatment for atherosclerotic renal artery stenosis

Approximately 30% of multiple myelomas (MMs) express cyclin D1 when assessed using immunohistochemical techniques. Cyclin D1 expression correlates with greater tumor burden in MM, because cyclin D1-positive cases are more frequently associated with extensive bone marrow involvement, i.e., high pathologic stage, than are cyclin D1-negative cases. The mechanisms that explain this association are unknown. To explore other differences between cyclin D1-positive and cyclin D1-negative MMs, we assessed 59 MMs immunohistochemically for several G1 cell-cycle regulatory proteins, including cyclin D1, E2F-1, p53, mdm-2, and p21waf-1, using routinely fixed and processed, paraffin-embedded bone marrow specimens. Twenty MMs (34%) were cyclin D1 positive, and 39 (66%) were cyclin D1 negative. Eighteen (90%) of 20 cyclin D1-positive MMs were Stage III, in contrast to 19 (49%) of 39 cyclin D1-negative MMs (P = .003). Cyclin D1-positive MMs were more likely to express E2F-1 (16/20 vs. 4/39, P < .001), p53 (11/20 vs. 10/39, P = .041), and p21waf-1 (12/20 vs. 7/39, P = .003). There was no significant difference in mdm-2 expression between these groups. We also assessed proliferation rate using an antibody specific for the Ki-67 antigen. A relatively high percentage (> 20%) of Ki-67-positive cells was found in cyclin D1-positive MMs compared with cyclin D1-negative MMs (13/20 vs. 3/39, P < 0.001). These results suggest that cyclin D1-positive MMs are more likely to possess additional derangements involving other G1 cell-cycle regulatory proteins. We speculate that these abnormalities might result in increased proliferation, thereby explaining the correlation between cyclin D1 expression and greater tumor burden.     

Asymptomatic carotid artery stenosis and stroke in patients undergoing cardiopulmonary bypass

PURPOSE: This study was undertaken to assess the natural history of carotid artery stenosis in patients undergoing cardiopulmonary bypass (CPB) at a Veterans Administration Medical Center. METHODS: Between January 1989 and August 1993, all patients undergoing CPB were offered preoperative carotid artery ultrasound screening as part of an investigative protocol. Patients were monitored in-hospital for the occurrence of perioperative neurologic deficit. RESULTS: A total of 582 patients underwent carotid artery ultrasound screening. Greater than 50% stenosis or occlusion of one or both internal carotid arteries was present in 130 patients (22%), with 80% or greater stenosis or occlusion of one or both arteries present in 70 patients (12%). In-hospital stroke or death occurred in 12 (2.1%) and 36 (6.2%) patients, respectively. Of the 12 strokes, five were global and seven were hemispheric in distribution. Of the five patients who had global events, none had evidence of carotid artery stenosis. However, of the seven patients who had hemispheric events, five had significant 50% or greater stenosis or occlusion of the internal carotid artery ipsilateral to the hemispheric stroke. Therefore the presence of carotid artery stenosis or occlusion was significantly associated with hemispheric stroke (no stenosis 0.34% vs stenosis 3.8%; p = 0.0072). Furthermore, the risk of hemispheric stroke in patients with unilateral 80% to 99% stenosis, bilateral 50% to 99% stenosis, or unilateral occlusion with contralateral 50% or greater stenosis was 5.3% (4 of 75). No strokes occurred in patients with unilateral 50% to 79% stenosis (n = 52). CONCLUSIONS: It is concluded that carotid atherosclerosis is a risk factor for hemispheric stroke in patients undergoing CPB.     

Transcranial Doppler ultrasound battery reliably identifies severe internal carotid artery stenosis

BACKGROUND: The clinical significance of plasma concentration of matrix metalloproteinase 9 (MMP-9) was investigated in patients with gastric cancer. METHODS: Plasma was obtained from 138 healthy individuals and 70 patients who underwent gastrectomy for gastric cancer at Aichi Cancer Centre between August 1994 and July 1995. Plasma concentrations of MMP-9 were measured using a one-step sandwich enzyme immunoassay employing monoclonal antibodies. RESULTS: Patients with gastric cancer had plasma higher concentrations of MMP-9 than normal subjects. Postoperative concentrations of MMP-9 were lower than preoperative levels. In addition to patients with advanced cancer, those with early gastric cancer also exhibited higher mean values of and positivity rates for MMP-9 than healthy individuals. Preoperative plasma MMP-9 concentration correlated closely with Union Internacional Contra la Cancrum tumour node metastasis (pTNM) stage, severity of T, N and M classification, and tumour size. CONCLUSION: Plasma MMP-9 concentration can be used for detection of primary or recurrent gastric cancer, and for estimation of tumour extent.     

Diagnosis of carotid artery stenosis: comparison of oculoplethysmography and Doppler supraorbital examination

Both Doppler supraorbital examination (OSM) and oculoplethysmography (OPG) were administered to 101 patients (202 arteries) to document the presence or absence of hemodynamically significant lesions of the internal carotid artery prior to angiography. There was no significant difference between the OSM and OPG with respect to diagnostic sensitivity or specificity, incidence of false-negative or false-positive results, and overall diagnostic accuracy. The diagnostic accuracy for the OSM and the OPG were 94.2% and 91.6%, respectively. In 171/202 (84.6%) arteries, the OSM and OPG were in diagnostic agreement, and the overall diagnostic accuracy of the combined tests was 97%. However, when the OSM and OPG did not agree (31/202 arteries, 15.4%), the diagnostic accuracy of neither the OSM nor the OPG was acceptable. Although the best diagnostic accuracy was obtained using two means of noninvasive cerebrovascular testing, in those instances where only one test may be available, the OPG would appear to be the test of choice. In those laboratories in which high diagnostic accuracy is obtained with the OSM, the addition of OPG testing will increase the overall diagnostic accuracy to a very high level. The presence of a midcervical bruit was found to have a very poor correlation with the incidence of hemodynamically significant stenoses of the internal carotid artery. Although both the OSM and OPG have minimal value in patients with symptomatic cerebrovascular disease, these tests play a very important role in screening patients for asymptomatic carotid stenosis or atypical cerebrovascular symptoms.     

Temporal variability of asymptomatic embolization in carotid artery stenosis and optimal recording protocols

BACKGROUND AND PURPOSE: Although asymptomatic embolization can be detected in patients with carotid artery stenosis, its temporal variability is unclear. An understanding of this is important in designing optimal recording protocols for future prospective studies of the predictive value of embolic signals (ES). We determined the effect of repeating and extending recording times in patients with symptomatic and asymptomatic carotid stenosis. METHODS: In 20 asymptomatic and 20 symptomatic subjects with > 60% carotid stenosis, we used transcranial Doppler ultrasound to record for ES in the ipsilateral middle cerebral artery. Three 1-hour recordings were performed on three separate days, and on one occasion (not necessarily the first) the recording was extended to 2 hours. The recordings were saved onto digital tape for subsequent blinded analysis. RESULTS: Marked temporal variability was seen in symptomatic patients in whom the cumulative proportion of subjects with ES increased from 10 (50%) after a single hour of recording to 12 (60%) and 15 (75%) after two and three recordings, respectively. Extending the recording to 2 hours increased the yield of ES-positive patients from 6 (30%) to 8 (40%). In symptomatic patients there was excellent agreement between whether patients were positive for ES during each of two consecutive 1-hour recordings (kappa = 0.78, P = 0.0003) but poor agreement between the results of two single-hour recordings performed on different days (kappa = 0.22, P = 0.27). In asymptomatic patients, 4 (20%) were ES positive during the first hour; this increased to 5 (25%) after the recording was repeated once, with no further increase after the third recording. Extending the recording to 2 hours increased the yield from 3 (15%) to 7 (35%). In contrast to symptomatic stenoses, in patients with asymptomatic stenoses there was fair agreement between whether patients were ES positive on two consecutive 1-hour recordings (kappa = 0.49, P = 0.01) or two single-hour recordings performed on different days (kappa = 0.48, P = 0.02). Symptomatic subjects were more likely to have ES (when all 1-hour recordings were considered, 24/60 versus 10/60; P = 0.0046). ES in symptomatic subjects had a higher relative intensity increase than in asymptomatic subjects (P = 0.01). CONCLUSIONS: The temporal variability of ES needs to be taken into account in the design of optimal recording protocols and comparisons of results from different studies. Extending the duration of recording beyond an hour in symptomatic stenoses is of less value, but repeating the recording on a different day will often identify additional subjects with ES. In intervention studies in symptomatic patients, the time since last symptoms must be considered. In asymptomatic stenosis, extending the duration of recording beyond an hour will increase the proportion of patients positive for ES.     

Is plaque formation in the common carotid artery representative for plaque formation and luminal stenosis in other atherosclerotic peripheral arteries? A post mortem study

A simple high-performance liquid chromatographic method was developed for the determination of ranitidine in human plasma. Prior to analysis, ranitidine and the internal standard (metoprolol) were extracted from alkalinized plasma samples using dichloromethane. The mobile phase was 0.05 M potassium dihydrogenphosphate-acetonitrile (88:12, v/v) adjusted to pH 6.5. Analysis was run at a flow-rate of 1.3 ml/min and at a detection wavelength of 229 nm. The method is sensitive with a detection limit of 1 ng/ml at a signal-to-noise ratio of 3:1, while the quantification limit was set at 15 ng/ml. The calibration curve was linear over a concentration range of 15-2000 ng/ml. Mean recovery value of the extraction procedure was about 90%, while the within-day and between-day coefficients of variation and percent error values of the assay method were all less than 15%.