Use of intraoperative duplex ultrasonography and routine patch angioplasty in patients undergoing carotid endarterectomy.

OBJECTIVE: To determine the value of routine patch angioplasty and intraoperative duplex ultrasonography (US) during carotid endarterectomy (CEA) for high-grade internal carotid artery stenosis. PATIENTS AND METHODS: The charts of 102 consecutive patients who underwent CEA with routine patching and intraoperative duplex US for treatment of high-grade carotid stenosis between June 1991 and January 1997 were reviewed retrospectively. Recurrent stenosis was defined as a narrowing in the common or internal carotid artery of more than 40%. RESULTS: Of 102 patients, 65 (63.7%) were men, and 37 (36.3%) were women (mean age, 72.4 years). Thirteen patients (12.7%) had bilateral CEAs. Intraoperative duplex US revealed abnormalities during 29 (25.2%) of 115 CEAs; 14 abnormalities (12.2%) were major and underwent immediate revision. No perioperative neurologic events or deaths occurred. Mean length of follow-up was 21.3 months (range, 1.3-72.6 months). Late neurologic events occurred in 2 patients, and 5 patients died during follow-up. All neurologic events and deaths were unrelated to the patients' carotid surgery. Twelve patients (11.8%) developed moderate restenosis (40%-69%). In 4 of these patients restenosis resolved during further follow-up. No patient developed severe recurrent carotid stenosis. CONCLUSION: Morbidity and mortality following CEA with routine patch angioplasty and intraoperative duplex US appear to be low. Routine intraoperative duplex US detects correctable technical problems that subsequently lead to a low incidence of symptomatic stenosis. The low incidence of recurrent stenosis suggests that routine postoperative follow-up may not be necessary or cost-effective unless the patient has symptoms or a contralateral stenosis.     

Diagnosing carotid stenosis by Doppler sonography: state of the art.

OBJECTIVE: The goal of this review article is to present the state of the art in the clinical applications and technical performance and interpretation of carotid sonographic examinations. METHODS: Relevant publications regarding color and duplex Doppler sonography (CDDS) of the carotid arteries extracted from a computerized database (MEDLINE) and from references cited in these articles not appearing on the Internet were reviewed. RESULTS: The ability to quickly and efficiently identify stenosis in the carotid artery is an important goal for clinicians and vascular surgeons. Identification of potentially treatable carotid stenosis enables selection of appropriate candidates for endarterectomy or stent implantation. Advances in performance and interpretation of carotid sonographic studies over the last 20 years have been driven by technological improvements in gray scale and CDDS examinations and have made carotid sonography an important means to reach this goal. On the basis of CDDS, intima-media thickness measurements and plaque location and characterization on gray scale imaging, flow disturbance and areas of stenosis on color Doppler sonography, and flow velocities on spectral Doppler sonography are obtained. The degree of the diameter of a stenosis of the internal carotid artery is the main parameter used for therapeutic approaches. Advantages and limitations of the method are included. CONCLUSIONS: Carotid sonography is a unique imaging method for the investigation of carotid abnormalities. Noninvasive, accurate, and cost-effective, it provides morphologic and functional information. It is increasingly becoming the first and often the sole imaging study before endarterectomy, whereas costly and invasive procedures are reserved for special cases.     

Duplex sonographic criteria for measuring carotid stenoses

PURPOSE: The aim of this retrospective study was to determine optimal duplex sonographic criteria for use in our institution for diagnosing severe carotid stenoses and to correlate those findings with angiographic measurements obtained by the European Carotid Surgery Trial (ECST), North American Symptomatic Carotid Endarterectomy Trial (NASCET), and Common Carotid (CC) methods of grading carotid stenoses. METHODS: We analyzed the angiographic data using the ECST, NASCET, and CC methods and compared the results with the duplex sonographic findings. We then calculated the sensitivity, specificity, positive and negative predictive values, and accuracy of the duplex sonographic method. Taking these parameters into account, the optimal intrastenotic peak systolic velocity (PSV) and end diastolic velocity (EDV) were derived for diagnosing severe stenoses according to the 3 angiographic methods. RESULTS: Optimal PSV and EDV values for diagnosing a 70% or greater stenosis in our laboratory were as follows: with the NASCET method of angiographic grading of stenoses, PSV 220 cm/second or greater and EDV 80 cm/second or greater, and with the ECST and CC methods, PSV 190 cm/second or greater, and EDV 65 cm/second or greater. The optimal PSV and EDV for diagnosing a stenosis of 80% or greater with the ECST grading method were 215 cm/second or greater and 90 cm/second or greater, respectively. CONCLUSIONS: Duplex sonography is a sensitive and accurate tool for evaluating severe carotid stenoses. Optimal PSVs and EDVs vary according to the angiographic method used to grade the stenosis. They are similar for stenoses 70% or greater with the NASCET method and for stenoses 80% or greater with the ECST method.     

Frequency,clinical significance and impact on therapy of duplex sonographic vascular findings in renal allograft dysfunction

Objective: The aim of this study was to establish the frequency of vascular findings by color-coded duplex sonography in renal allografts with dysfunction. Furthermore, we estimated the clinical significance of these findings and their impact on therapy. Methods: A total of 184 duplex scans were performed in 119 patients (68 male, 51 female) with insufficient or declining diuresis and/or rising creatinine. Color-coded duplex sonography was used to examine the entire length of the iliac vessels as well as the central and peripheral renal arteries and veins. Results: A total of 45 abnormal vascular findings were identified in 37 patients (31%, including 21 transplant artery stenoses (7 > 50%), 5 iliac stenoses, 11 AV fistulas and 8 venous stenoses. Of all vascular findings, 4 were determined to be responsible for functional deterioration, including 2 high grade kinking stenoses of the transplant artery in the early post-operative period, 1 transplant artery stenosis in the middle segment and 1 high-grade iliac artery stenosis. The other abnormal vascular findings did not appear to cause renal dysfunction. Biopsy results did not explain the functional deterioration in 1.6% of patients without vascular findings but in 13% of patients with vascular findings. Conclusions: Abnormal duplex sonographic vascular findings occur frequently in renal allografts but only a few of them are responsible for deterioration of graft function. Histologic findings insufficient to explain renal dysfunction possibly indicate a potential vascular cause. Due to its non-invasiveness, color-coded duplex sonography is a useful diagnostic tool but all findings need to be interpreted strictly in a clinical context.     

Duplex sonography in patients with hemispheric symptoms

Many patients with hemispheric neurologic symptoms do not have operative stenoses of the extracranial carotid arteries. In order to assess the frequency of such atherosclerotic lesions, 154 patients with documented hemispheric events underwent duplex Doppler examinations of the extracranial carotid bifurcation to assess if operative stenosis (70% to 80% stenosis) was present. Seventy-two patients with transient ischemic attacks (TIA), 62 patients with cerebrovascular accidents (CVA), and 20 patients with amaurosis fugax (AF) were studied. Sixty-nine percent of patients with TIAs demonstrated a less than 50% stenosis, 52% of patients with CVAs demonstrated a less than 50% stenosis, and 65% of patients with AF demonstrated a less than 50% stenosis on duplex Doppler examination. Intra-arterial digital subtraction angiography (IADSA) was performed in 35 of 154 patients. In all of these 35 cases, ultrasound and angiographic studies agreed with respect to whether or not a greater than 50% stenosis was present. Our findings support the use of duplex Doppler sonography as a triage procedure in patients with hemispheric events in order to determine those patients who have significant carotid stenoses and who may be potential operative candidates.     

Duplex ultrasonography is an efficient diagnostic tool for the detection of moderate to severe internal carotid artery stenosis

BACKGROUND: The aim of this prospective national multicentre study with 10 participating university and county hospitals was to establish the diagnostic accuracy of carotid duplex sonography in the identification of >or=70% internal carotid artery (ICA) stenosis defined according to European Carotid Surgery Trial (ECST) criteria. METHODS: In 134 patients, aged 69 +/- 9 years, ICA stenoses were identified by routine carotid duplex ultrasonography, confirmed angiographically within 2 months, and graded according to ESCT criteria. The accuracy of carotid duplex to detect ICA stenosis >or=70% was assessed using receiver operating characteristic (ROC) analysis with carotid angiography as a reference. RESULTS: Measurement of peak systolic velocity in ICA (PSV(ICA)) identified ICA stenosis >or=70% with high diagnostic accuracy that was Doppler angle dependent resulting in different optimal PSV(ICA) cut points within the angle range 0 degrees -49 degrees (1 x 7 m s(-1)) and 50 degrees -62 degrees (2 x 3 m s(-1)). The diagnostic discrimination was significantly better when narrow Doppler angles (0 degrees -49 degrees ) were used (P<0 x 01) providing the sensitivity of 98 +/- 2% and specificity of 94 +/- 4%. DISCUSSION: Ultrasound duplex technique identifies moderate to severe (>or=70%) ICA stenoses (ECST criteria) with high degree of accuracy that can be further improved by the use of Doppler angle specific optimal PSV(ICA) cut points.     

Color duplex sonography of occlusion of the common carotid artery with reversed flow in the extracranial internal carotid artery

In a small percentage of cases with an occluded common carotid artery (CCA), the patency of the arteries beyond the carotid bulb is preserved. Color duplex sonography is useful for assessing blood flow in these vessels. We present a case of retrograde flow in an internal carotid artery (ICA) with an occluded ipsilateral CCA identified using color duplex sonography in a 70-year-old man with diabetes and known atherosclerotic disease. Color duplex sonography revealed that the right CCA was totally occluded near its origin and that flow was re-established at the bulb. Flow in the right ICA was directed cephalad, with a low-frequency, damped waveform; flow in the right external carotid artery (ECA) was bidirectional, with increased reversed diastolic flow. Extensive atherosclerotic lesions were also found in the left side. Endarterectomy of the left carotid bifurcation was performed. Follow-up color duplex sonography 3 months later revealed a small increase of stenosis in the left CCA and mild stenosis in the left ICA. The right CCA remained occluded, but reversed flow with a high-resistance flow pattern was seen in the ipsilateral ICA that supplied the ECA, which had cephalad-directed flow.     

Ultrasonographic findings that predict carotid restenosis after endoarterectomy

Objective: To analyze ultrasonographic changes after carotid endoarterectomy and to relate the changes to recurrent carotid stenosis. Methods: Eighty patients who underwent carotid endarterectomy have been followed-up by duplex scanning. The B-mode ultrasonography was performed at 7 days, 1 month, 3 months, 6 months, and every 6 months after the operation. The postoperative echotomographic findings have been correlated to the appearance of the restenosis. The patients were divided into two groups: group A with postoperative restenosis (12 cases) and group B without restenosis (68 cases). The findings have been considered as normal (visibility of the suture line, and limits of the endarterectomy) and pathological (intimal flaps, lesions from clamp, residual fragments of the plaque, ectasia of the endarterectomized segment, visibility of the blood flow in the jugular vein). Results: The time of appearance of the neointima was significantly shorter in group A than in group B. The visibility of blood flow in B-mode echograms was significantly more present in patients of group A (75%) than in patients of group B (4.4%). Conclusions: This study confirms that patients with a high risk of postoperative restenosis are those with visibility of the blood flow in the jugular vein associated to early appearance of the neointima (within 3 months after the operation). On the other hand, other factors as the visibility of the suture line, the transition points between the endarterectomized portion of the vessel, the intimal flaps and the ectasia of the treated segment are not correlated to the appearance of restenosis.     

Color-coded duplex ultrasound compared to CT angiography for detection and quantification of carotid artery stenosis.

OBJECTIVE: The purpose of this study was to compare findings on color-coded duplex ultrasound and CT angiography for grading internal carotid artery stenosis, and to investigate whether both these imaging modalities are necessary for an accurate diagnosis of carotid stenosis in the pre-surgical assessment of the internal carotid artery. PATIENTS AND METHODS: We examined 92 internal carotid arteries from 46 randomly chosen patients with suspected carotid stenosis by color-coded duplex ultrasound and by three-dimensional CT angiography (CTA). This retrospective study adhered to international guidelines with gradings of mild, moderate, severe, and occlusive carotid disease. RESULTS: The study demonstrated agreement between the degree of stenosis found on color-coded duplex ultrasound and that found on CTA in 78% of cases overall and in 79% of patients requiring surgical intervention. When compared to CTA, color-coded duplex ultrasound yielded a sensitivity of 78.9% and a specificity of 96.3%. Although findings on color-coded duplex ultrasound and CTA were comparable, disagreement affecting treatment decision occurred in 10:92 arteries. CONCLUSION: CTA was not found to be beneficial for patients exhibiting mild stenosis on color-coded duplex ultrasound, as none of the mild groupings found by sonography were interpreted as severe or occluded by CTA. However, CTA may be an important adjunct to color-coded duplex ultrasound regarding the categories of moderate, severe and occluded when carotid endarterectomy is considered.     

312例颅内外动脉支架置入术后再狭窄的危险因素研究

目的:探讨颅内外动脉支架置入术后再狭窄的危险因素。方法:对312例成功实施颅内外动脉支架置入的患者随访1年,观察随访期血管腔再狭窄情况、术后用药及危险因素。应用单因素和Logistic多因素回归分析。结果:312例患者中,24例(7.7%)血管腔再狭窄。单因素分析显示:再狭窄与非再狭窄患者中吸烟、糖尿病、2个以上部位狭窄、术后规范用药者所占比例差异有统计学意义(P<0.05)。颅外颈动脉再狭窄率显著低于椎动脉和大脑中动脉(P<0.05)。Logistic回归分析显示:吸烟、2个以上部位狭窄与再狭窄呈正相关(OR值分别为4.358和6.981);支架部位(颈动脉)、术后规范服药与再狭窄呈负相关(OR值分别为0.893和0.931)。发生心肌梗死11例,脑出血3例,脑梗死8例;死亡5例(1.6%);同侧脑梗死发病率为1.6%。结论:吸烟、2个部位以上狭窄、支架部位、术后规范用药是支架置入术后血管腔再狭窄的独立危险因素。     

Characteristic Sonographic Findings of Early Restenosis After Carotid Endarterectomy

Objective. Restenosis of the carotid artery after carotid endarterectomy (CEA) is a major complication. The frequency, time of occurrence, and tissue characteristics of carotid restenosis were assessed with sonography. Methods. Two hundred sixteen patients who had CEA for carotid stenosis were studied; follow‐up sonography and magnetic resonance angiography were done 2 weeks, 3 months, and then every year after CEA. On sonography, restenosis was defined as an internal carotid artery (ICA) with a peak systolic velocity of 170 cm/s or greater or a maximum area of stenosis of 90% or greater. Results. During 605 artery‐years of follow‐up, 18 patients (7.5%) were found to have restenosis on sonography: 4 at 3 months, 11 at 1 year, and 3 at 2 years after CEA. At the time that restenosis was detected, in all 18 ICAs the peak systolic velocity exceeded 200 cm/s and had more than doubled since the last measurement (mean ± SD, 103 ± 27 to 321 ±107 cm/s), whereas the area of stenosis exceeded 90% in 6 patients, and magnetic resonance angiography revealed stenosis of 60% or greater in 8 patients. On sonography, all of the restenotic plaques were isoechoic and concentric. The restenosis was asymptomatic in 17 patients. Vascular risk factors or the severity of initial carotid stenosis before CEA were not associated with development of restenosis. Eleven patients had successful endovascular therapy, and the others received medical treatment. Conclusions. A marked increase in the flow velocity through an operated ICA is a good indication of restenosis. The isoechogenicity and concentricity of the restenotic plaques suggest that the restenosis is primarily the result of intimal hyperplasia.     

Contrast-enhanced power Doppler sonography of the intestinal wall in the differentiation of hypervascularized and hypovascularized intestinal obstructions in patients with Crohn's disease.

OBJECTIVE: To use power Doppler sonography to quantify the vascularization in the area of stenosed bowel segments in patients with Crohn's disease and to draw conclusions from these findings with regard to the development of these stenoses. METHODS: The study collective included 11 patients with confirmed Crohn's disease and sonographically visualized stenoses of the small bowel together with intermittent abdominal cramping as a clinical correlate. Power mode examination was repeated after application of a sonographic signal-enhancing agent. Semiquantitative evaluation based on the sonographically indicated degree of vascularization led to the presumptive diagnosis of either inflammatory or cicatricial intestinal obstruction. Sonographic diagnoses were compared with the findings of surgery and subsequent histologic examination or with patients' clinical responses to conservative therapy. RESULTS: Nine of 11 patients underwent surgery within 1 year of examination. All 3 cases in which sonography had facilitated the diagnosis of cicatricial stenosis were confirmed at postoperative histologic examination; similarly, the surgical and histologic findings in the other 6 patients confirmed the sonographic diagnosis of inflammatory stenosis. CONCLUSIONS: Power Doppler sonography in combination with the use of a signal-enhancing agent appears to be effective in the recognition of predominantly cicatricial stenoses in patients with Crohn's disease.     

Carotid stenosis: diagnosis, patient selection, therapy

Atheromatosis frequently develops in the carotid bifurcation, leading to significant stenoses of the internal carotid artery. The associated risk of stroke reaches 20-25% during the first three years for a high-grade symptomatic stenosis and 2-3% per year for a high-grade asymptomatic stenosis. The diagnosis of carotid stenosis is made after occurrence of a cerebral ischemic event or during an angiologic examination, mainly using Doppler/Duplex-sonography. Ultrasonography also enables an accurate determination of the grade of stenosis and accordingly the risk of stroke. Non-invasive MR- or CT-angiography is presently preferred to digital subtraction angiography to confirm the sonographic findings and prepare for an intervention. The intervention has to be decided individually for each patient. It is mandatory that the estimated risks of operation + best medical therapy be significantly lower than the risks of medical therapy alone; otherwise, the benefit of the intervention is lost for the patient. Only the mortality and major morbidity are taken into consideration to estimate the risks of an intervention. Local and systemic complications are transitory and do not influence the final outcome. A high-grade symptomatic stenosis (70-99%) should be operated upon whenever possible. A middle-grade symptomatic stenosis (50-69%) is treated operatively only if the associated risk of stroke is estimated to be high. A high-grade asymptomatic stenosis is operated upon only if the estimated perioperative risks are very low (< 3%). A middle-grade asymptomatic stenosis as well as low-grade stenoses (< 50%) should not be operated, but treated with the best medical therapy available. Carotid endarterectomy is established as method of first choice to treat a carotid artery stenosis. A major complication rate as low as 1% can be expected in experienced centres. The long-term results of carotid endarterectomy are well documented and the incidence of restenosis is very low. Endovascular angioplasty with stenting is increasingly performed as an alternative to the open operation. Presently, the scientific evidence is still lacking to recommend this method as primary therapy; however, progress in the field is constant and we expect new technical improvements which should increase the safety and efficacy of the procedure in the near future.     

Sonographic evaluation of vascular injuries.

OBJECTIVE: The purpose of this presentation is to highlight the color Doppler duplex sonographic features of procedure-related and blunt or penetrating trauma-related vascular injuries. METHODS: Different kinds of vascular complications such as pseudoaneurysms, arteriovenous fistulas, dissection, and thrombosis are discussed. Cases of vascular injuries in the extremities, neck, and abdomen are presented to illustrate the spectrum of sonographic appearances. RESULTS: Color Doppler duplex sonography is valuable in the diagnosis and monitoring of most vessel injuries and in the treatment of pseudoaneurysms. It is useful for flow analysis and for follow-up after treatment. However, because of limitations inherent to sonography, such as bones, air, casts, skin burns, and relatively slow performance of the test, magnetic resonance imaging, computed tomography, and angiography are necessary for further evaluation in selected cases. CONCLUSIONS: Color Doppler duplex sonography is a widely available, noninvasive, and accurate technique for evaluating vascular injuries and should be the first-line imaging modality in most patients.     

Noninvasive estimation of the pressure gradient across stenoses using sonographic contrast: in vitro validation.

OBJECTIVE: Because velocity measurements to estimate the degree of arterial stenosis are susceptible to local and systemic factors, we aimed to investigate the feasibility of estimating the pressure gradient across a stenosis noninvasively by using sonographic contrast. METHODS: Using a gravity-fed flow system, a 1:4000 dilution of a contrast agent in water was circulated through silicone tubes that had either focal or long-segment stenoses of varying severity in a water bath. We measured the cross-sectional areas of the normal and stenotic regions with B-mode sonography and the flow velocity with spectral Doppler sonography and calculated the pressure gradients across the stenoses using the empirically derived Young mathematical model and the simplified Bernoulli equation. Estimated gradients were compared with those measured manometerically. RESULTS: Both methods yielded estimates of pressure gradients that correlated with measured gradients (r > 0.988). In focal and long-segment stenoses, the Young model yielded gradients that agreed more closely with manometerically measured values than the Bernoulli equation (+/- 8% versus -24%-57%). Both methods were highly dependent on the ability to measure the luminal cross-sectional area. The presence of sonographic contrast in the vascular lumen highlighted the inner wall, allowing the accurate measurement of the luminal area to +/- 3.0%. CONCLUSIONS: The pressure gradient can be estimated across stenoses noninvasively. The Young model was more accurate than the simplified Bernoulli equation in this model using steady flow. Estimated gradients are highly dependent on the definition of the vascular lumen, a process aided by the use of sonographic contrast.     

Prospective study of the effectiveness and durability of carotid endarterectomy

In a series of 252 consecutive patients who underwent 282 carotid endarterectomies, we conducted clinical and angiographic follow-up for 2 to 6 years (mean, 3.2 years). Digital subtraction angiography (DSA) was done postoperatively in 95% of cases. Clinical follow-up was achieved in 97% of cases, and DSA follow-up was obtained in 66% of cases. The overall group had a 1% operative minor morbidity (three cases of minimal new neurologic deficit), no major morbidity, and a 0.7% mortality (one death from stroke and one from myocardial infarction). Complications correlated well with the patient's preoperative risk category. During follow-up, 10 minor strokes, only 1 of which was attributable to the reconstructed artery, and 10 transient ischemic attacks, 3 of which were presumably related to recurrent stenosis, occurred. Asymptomatic mild to moderate restenosis of the internal carotid or common carotid artery was identified in 10% of follow-up DSAs and severe stenosis or occlusion in 3%. Stenosis in the opposite common carotid or internal carotid artery progressed in 48 cases (26% of follow-up DSAs and ultrasound studies), and 10 of these became symptomatic. An actuarial analysis of patients who had endarterectomy indicated that the cumulative probability of ipsilateral stroke was 1.5% at 1 month and 2% at 5 years. The cumulative probability of ipsilateral stroke, transient ischemic attack, or reversible ischemic neurologic deficit was 4% at 1 month and 8% at 5 years or less than 1% per year after the first month, with censoring at the time of the second surgical procedure.     

Duplex features of vein graft stenosis and the success of percutaneous transluminal angioplasty.

PURPOSE: To determine if criteria exist that are correlated to a successful outcome after balloon angioplasty for vein graft stenosis. METHODS: During a 5-year period, duplex surveillance of 380 infrainguinal vein bypasses identified 76 hemodynamically failing grafts (87 stenoses) requiring intervention. Percutaneous transluminal angioplasty (PTA) was selected over surgical repair based on 3 criteria: time interval from primary grafting procedure, vein graft diameter, and stenosis length. The 28 (32%) stenoses (20 grafts) treated by PTA were used in a retrospective analysis to test if any variables favored a successful outcome. Patient and lesion characteristics, graft patency, and restenosis following PTA were correlated with duplex features of the stenosis recorded prior to, immediately after, and at 3- to 6-month intervals postprocedurally. RESULTS: Lesion characteristics that correlated with a successful outcome were vein size > or = 3.5 mm, lesion length < 2 cm, and appearance > 3 months after surgery. Conduit type, PTA site, patient demographics, and indication for bypass did not correlate with PTA durability. Nineteen lesions in 13 grafts met these criteria (group 1), while 9 stenoses in 7 grafts did not (group 2). Lesion severity based on duplex velocity measurements were similar in both groups before (p = 0.40) and after (p = 0.32) treatment. During the mean 21-month follow-up, group 1 grafts required less intervention (p = 0.035). At last follow-up, hemodynamic changes were durable in group 1 (p = 0.0068) but not in group 2 (p = 0.39). CONCLUSIONS: Selection of vein graft stenoses for treatment by PTA can be based on temporal and duplex data. PTA of short (< 2 cm) stenoses in good caliber veins (> or = 3.5 mm) appearing > 3 months after bypass placement was durable with a late intervention rate of approximately 10%. Direct surgical repair or replacement is recommended for early (< 3 months) and/or long segment stenoses that develop in small caliber conduits.     

Carotid sonography and transesophageal echocardiography in patients with ischemic stroke or transient ischemic attack in the territory of the carotid artery

PURPOSE: To assess the benefit of combining carotid sonography and transesophageal echocardiography (TEE) for the evaluation of patients with stroke or transient ischemic attack (TIA) in the territory of the carotid artery. METHODS: During a 2-year period in Turku University Hospital, consecutive in patients with stroke or TIA who were candidates for carotid endarterectomy and for oral anticoagulation were evaluated with carotid sonography for symptomatic moderate (50-69%) or severe (>or=70%) internal carotid artery (ICA) stenosis, and with TEE for potential cardiac sources of embolism. RESULTS: In 20% (40/197) of patients, a severe symptomatic ICA stenosis and/or a major risk factor for a cardiac source of embolism were found. In 56% (110/197) of patients, a moderate or severe symptomatic ICA stenosis and/or a potential cardiac source of embolism were found, whereas 11% (21/197) of patients had both a moderate or severe symptomatic ICA stenosis and a potential cardiac source of embolism. CONCLUSIONS: This study suggests that the presence of a moderate or severe symptomatic ICA stenosis does not exclude the presence of a potential cardiac source of embolism and vice versa. Carotid sonography and TEE complement each other and are valuable diagnostic tools that should be recommended in patients with ischemic stroke or TIA in the territory of the carotid artery when they are candidates for carotid endarterectomy and for oral anticoagulation.     

Short- and long-term outcome after carotid artery stenting with neuroprotection: single-center experience within a prospective registry

BACKGROUND : Carotid artery stenting is an alternative method to surgical endarterectomy for treatment of carotid artery stenosis. METHODS AND RESULTS : Three hundred and seventy-one consecutive patients (71+/-9 years) undergoing 405 carotid artery interventions at a single cardiologic center were studied prospectively within a therapy registry. In general, the interventional procedure was performed using neuroprotective devices to prevent distal embolization. Stents were used routinely whenever possible. Independent neurological assessment took place prior to and after carotid stenting. The neurological event rate was assessed in the early (<30 days) and late post interventional period. In asymptomatic patients, 286 interventions were done with a 30-day stroke rate of 1.3% (ipsilateral 1.0%). In symptomatic patients, strokes occurred in a significantly (p<0.005) higher rate of 5.0% after 119 interventions (all ipsilateral). At long-term follow-up (mean 728+/-548 days) additional strokes occurred ipsilateral to the side of carotid intervention in 0.4% of asymptomatic patients (1.7% of symptomatic patients); contralateral strokes were seen at long-term follow-up in 1.1% of asymptomatic (1.7% of symptomatic) patients. Due to their comorbidities, 1.6% of patients died early, and an additional 11.1% late after carotid stenting. CONCLUSION : Carotid artery stenting with the general use of neuroprotective devices yields acceptable shortterm results with respect to neurological events. Asymptomatic patients have significantly less periprocedural strokes than symptomatic patients. Neurological events during long-term follow-up are rare, in particular ipsilateral to the side of carotid stenting. Thus, carotid artery stenting with neuroprotection is a safe method for carotid revascularization, with acceptable periprocedural events, particularly in asymptomatic patients, and a good long-term neurologic outcome.     

New Doppler parameters for carotid stenosis

The recently published clinical trials of carotid endarterectomy marked a turning point in carotid sonography, because they provided justification for seeking carotid stenosis with ultrasound in both symptomatic and asymptomatic patients. These trials also were a turning point because they set a new standard for measuring carotid stenosis from arteriograms, based on the comparison of the least diameter of the residual internal carotid artery (ICA) lumen and the diameter of the normal, distal ICA. The adoption of this new standard for arteriographic measurement has necessitated the redefinition of velocity criteria for duplex Doppler diagnosis of ICA stenosis. This article discusses the methods for establishing Doppler velocity criteria for the identification of clinically significant carotid ICA stenosis, based on the new standard for arteriographic measurement.