Endarterectomy for mild cervical carotid artery stenosis in patients with ischemic stroke events refractory to medical treatment

A 62-year-old man and a 44-year-old man with unilateral cervical carotid artery stenosis (less than 50% with echolucent plaque and ulceration) suffered recurrent ischemic stroke events despite treatment with antiplatelet and anticoagulation drugs. Carotid endarterectomy (CEA) was performed under transcranial Doppler monitoring for the detection of micro-emboli using a microscope inserted through a skin incision to minimize pressure on the carotid arteries. The atheroma plaque included an ulcer with fresh thrombi in both patients. Both patients awoke from anesthesia without new neurological deficits, and no ischemic stroke events have recurred since CEA. Endarterectomy is an effective method for preventing stroke in patients with severe carotid stenosis (>70%), but the efficacy of this procedure for mild carotid stenosis (<50%) remains uncertain, regardless of carotid plaque characteristics. The present cases suggest that even mild stenosis of the cervical carotid artery may result in ischemic stroke events that are refractory to medical treatment if the stenosis is associated with echolucent plaque with ulceration. Endarterectomy is recommended to prevent further stroke in such patients.     

Surgical treatment of internal carotid artery occlusion

PURPOSE: Nonoperative treatment of recent internal carotid artery (ICA) occlusion is associated with increased recurrent stroke rates. We analyzed our results of carotid endarterectomy (CEA) for treatment of symptomatic recent ICA occlusion to evaluate its feasibility, safety, and outcomes. METHODS: From 1990 to 2002, all patients with transient ischemic attack (TIA), amaurosis fugax, and minor stroke underwent duplex ultrasound (US) scanning and arteriography to confirm the diagnosis of ICA occlusion. Within 2 weeks of symptom onset, patients underwent operative exploration with attempted CEA. ICA occlusion was detected at preoperative angiography and confirmed at surgery. Patients with extensive ICA plaque not amenable to endarterectomy underwent external CEA with ICA ligation. RESULTS: Over 12 years, 87 patients with symptomatic ICA occlusion underwent 90 operations for ICA exploration. In 30 patients (18 men, 12 women) with TIA (45%), amaurosis fugax (19%), or minor stroke (36%), CEA to treat ICA occlusion was technically successful. There was 1 postoperative stroke, 2 asymptomatic internal carotid occlusions, and no restenoses (mean follow-up, 26 months; range, 1-93 months). In 57 patients (37 men, 20 women) with TIA (41%), amaurosis fugax (27%), or stroke (32%) in whom CEA was unsuccessful, external CEA was performed. In this group there were no postoperative strokes, 2 asymptomatic external carotid artery occlusions, and 1 restenosis (>70%) (mean follow-up, 22 months; range, 1-73 months). There were no late strokes in either group. CONCLUSION: Operative exploration and endarterectomy to treat symptomatic ICA occlusion is feasible and safe. Patients with symptomatic ICA occlusion should be considered candidates for CEA.     

转流管在颈动脉内膜切除术中的应用(附11例报告)

目的:评价转流管在颈动脉内膜切除术中的所提供保护作用。方法:回顾性分析本科2002年10月以来11例施行颈动脉内膜切除术中使用转流管的经验,此11例病人全部合并对侧颈内动脉闭塞或重度狭窄,均在颈动脉转流管保护下完成手术。结果:术中、术后无死亡,且无中风等严重并发症发生。结论:在严格掌握适应证的前提下,颈动脉内膜切除术中使用转流管是安全的,对脑组织具有良好的保护作用。     

Carotid artery endarterectomy solely based on duplex scan findings

The purpose of this study was to review experience with carotid artery surgery based on findings obtained solely from duplex scanning with special regard to unexpected findings during surgery and the early outcome. From January 1993 through December 1999, 271 consecutive patients underwent 287 carotid endarterectomies (CEAs), 229 (80%) of which were performed solely based on duplex scan findings. During the study period 5,932 carotid artery duplex scans were performed in 4,466 patients. Of 589 patients with internal carotid artery (ICA) stenosis 70%, 246 underwent CEA compared to 25 of 156 with 50-69% ICA stenosis. The indications for CEA were transient ischemic attack (TIA) in 88 (30.7%), amaurosis fugax in 60 (20.9%), previous stroke in 91 (31.7%) and asymptomatic disease in 48 (16.7%) cases. There were no statistically significant differences between the groups operated on with and without preoperative angiography with respect to the indications for surgery, associated risk factors, or the degree of stenosis on the contralateral side. In patients undergoing surgery without angiography, there were no unexpected findings that influenced the performance of surgery, in all except 1. There were no significant differences in perioperative morbidity and mortality in patients undergoing surgery with and without conventional angiography. The combined mortality and major stroke rates were 3.4% and 2.2%, respectively. It is concluded that CEA can safely be performed without preoperative angiography in cases with conclusive duplex scan findings.     

颅外段颈动脉狭窄的治疗策略

目的：探讨颅外段颈动脉粥样硬化性狭窄的治疗方法。方法回顾性分析上海中山医院血管外科2012年1～6月51例颅外段颈动脉粥样硬化性狭窄患者的临床资料,16例行颈动脉内膜剥脱术（carotid endarterectomy,CEA）,35例行颈动脉支架置入术（ carotid artery stenting ,CAS）。结果51例手术均获成功,1例CAS术后即刻脑卒中,1例CEA术后第3天短暂性脑缺血发作（transient ischemic attack,TIA）,1例CAS术后颈动脉窦压迫。全组术后随访9～15个月,平均13．6月,复查颈动脉B超,无严重再狭窄。结论根据颅外段颈动脉粥样硬化性狭窄患者的相关医学资料,对于有下列情况之一的患者我们倾向于行CEA：①6个月内1次或多次TIA,且颈动脉狭窄度≥70％;②6个月内1次或多次轻度非致残性卒中发作,症状或体征持续超过24小时且颈动脉狭窄度≥70％;③对于经颈部血管CTA和颈动脉全脑血管造影发现的颈动脉狭窄段≥2 cm。对于有下列情况之一的患者我们倾向于行CAS：①无症状性颈动脉狭窄度≥70％;②有症状性狭窄度范围50％～69％;③无症状性颈动脉狭窄度＜70％,但血管造影或其他检查提示狭窄病变处于不稳定状态。     

Improvement of carotid blood flow after carotid endarterectomy--evaluation using intraoperative ultrasound flow measurement.

OBJECTIVES: to examine the relationship between the degree of extracranial internal carotid artery (ICA) stenosis and changes in the ipsilateral ICA blood flow after carotid endarterectomy (CEA). MATERIALS AND METHODS: in a prospective study we studied 51 patients with unilateral 60-99% ICA stenosis (median degree 84%, asymptomatic stenosis n = 13, symptomatic stenosis n = 38). The degree of ICA diameter stenosis was determined by ex-vivo plastination of the surgically removed atherosclerotic specimen and video-assessed planimetry. Intraoperative transit time ultrasound flow measurements of the carotid arteries were performed before and after CEA. Blood flow changes were assessed by mathematical approximations. Statistics were done by use of the Wilcoxon signed Rank test. RESULTS: common carotid artery (CCA) and ICA median blood flow increased after CEA from 370 and 130 ml/min to 450 and 282 ml/min, respectively (p <.001). The relative increase of ICA blood flow was 5% and 18% for 60-69% and 70-79% ICA stenosis (n.s.) but 70% and 247% for 80-89% and 90-99% stenosis (p <.001 each). Mathematical evaluation (fourth-polynomal function) determined a significant increase of carotid blood flow after CEA in ICA stenosis of > or =82.3%. CONCLUSIONS: in the absence of severe contralateral ICA occlusive disease a significant increase of ipsilateral ICA blood flow by CEA can be expected in patients with an ICA stenosis of > or =82.3% (linear degree of stenosis, ECST criteria).     

Carotid artery disease: clinical features and management

The most common single cause of ischaemic carotid territory stroke is thromboembolism from stenoses in the extracranial internal carotid artery (ICA). In the majority, embolism is preceded by an acute change in plaque morphology predisposing the patient to overlying thrombus formation and embolization. The management of patients with carotid artery disease mandates risk factor modification, antiplatelet and statin therapy in everyone. There is grade A, level I evidence that recently symptomatic patients with 50–99% NASCET stenoses gain significant benefit from carotid endarterectomy (CEA), despite a small risk of perioperative stroke. Maximum benefit is conferred if the patient undergoes surgery as soon as possible after onset of symptoms. The management of patients with asymptomatic disease remains controversial. The 2018 European Society for Vascular Surgery (ESVS) carotid guidelines now advise that asymptomatic patients with a 60–99% stenosis who have one or more clinical/imaging features that might make them at higher risk for stroke on medical therapy should be considered for CEA, with the remainder being treated medically. The 2018 ESVS carotid guidelines also advise that carotid artery stenting may be an alternative to CEA in ‘average risk’ symptomatic and asymptomatic patients, although CEA is still the preferred option when treating patients within 14 days of symptom onset.     

Outcome in Patients with Symptomatic Occlusion of the InternalCarotid Artery

OBJECTIVES: to assess whether the risk of recurrent ischaemic stroke in patients with symptomatic internal carotid artery (ICA) occlusion has changed over the past decades, to determine risk factors for the occurrence of ischaemic stroke and to assess the risk of endarterectomy (CEA) of a severe contralateral ICA stenosis. DESIGN: retrospective cohort study. PATIENTS AND METHODS: patients with symptomatic ICA occlusion were identified from duplex registry files between 1991 and 1995. Information was obtained on vascular risk factors, performance of CEA for a contralateral ICA stenosis and on recurrence of ischaemic stroke. The rate of complications occurring within 30 days after CEA of the contralateral ICA in patients with symptomatic ICA occlusion was compared with the risk of CEA in patients with asymptomatic ICA occlusion and severe contralateral ICA stenosis (symptomatic or asymptomatic). RESULTS: ninety-seven patients were identified. Mean follow-up time was 26 months. The annual risk of (non-)fatal stroke was 5.3% for all strokes (95% CI 2. 9%-9.6%) and 3.8% for ipsilateral stroke (95% CI 1.9%-7.7%). Hyperlipidaemia and severe stenosis of the contralateral ICA were independent risk factors. Twenty-two of 32 patients with a severe stenosis of the contralateral ICA underwent CEA, of which one patient died and three suffered a minor ischaemic stroke. The perioperative risk of CEA in the control group of 20 patients with asymptomatic contralateral ICA occlusion was 0% (0 of 20). CONCLUSIONS: outcome in patients with symptomatic ICA occlusion has not substantially improved over the years. CEA for severe stenosis of the contralateral ICA carried a relatively high risk in our series, but deserves to be studied in a controlled design.     

Magnetic resonance angiography, digital subtraction angiography and Doppler ultrasonography in detection of carotid artery stenosis: a comparison with findings from histological specimens

Background

Patients' life expectancy, clinical symptomatology and the extent of carotid stenosis are the most important factors when deciding whether to perform carotid endarterectomy (CEA) in patients with carotid stenosis. Therefore, the accuracy of measuring carotid stenosis is of utmost importance.

Methods

Patients with internal carotid artery (ICA) stenosis were investigated by digital subtraction angiography (DSA), Doppler ultrasonography (DUS) and magnetic resonance angiography (MRA). Atherosclerotic plaque specimens were transversally cut into smaller segments and histologically processed. The slides were scanned and specimens showing maximal stenosis were determined; the minimal diameter and the diameter of the whole plaque were measured. DSA, DUS and MRA measurements were obtained in 103 patients. A comparison between preoperative and histological findings was performed. In addition, correlation coefficients were computed and tested.

Results

Results show a significant correlation for each of the diagnostic procedures. Mean differences in the whole cohort between preoperative measurements and the histological measurements are as follows: angiographic measurement of carotid stenosis underestimated histological measurement by 14.5% and MRA by 0.7%, but DUS overestimated by 6.6%. The results in severe stenosis (≥70%) are as follows: angiographic measurement underestimated the histological measurements by 2.3%, but MRA overestimated by 12.1% and DUS by 11.3%. The results in moderate stenosis (50–69%): angiographic measurement underestimated the histological measurements by 12.3%, but MRA overestimated by 0.2% and DUS by 7.2%. The results in mild stenosis (30–49%): angiographic measurement underestimated the histological measurements by 24.7% and MRA by 7.6%, but DUS overestimated by 3.3%.

Conclusions

Our study confirms that DSA underestimates moderate and mild ICA stenosis. DUS slightly overestimated moderate ICA stenosis and highly overestimated high-grade ICA stenosis. MRA proved to be accurate in detecting moderate ICA stenosis, but slightly underestimated mild stenosis and overestimated high-grade stenosis. The surgeon should be aware of these discrepancies when deciding whether to perform CEA in patients with ICA stenosis.     

Prevalence of micro-emboli in symptomatic high grade carotid artery disease: a transcranial Doppler study.

BACKGROUND AND PURPOSE: Echolucent carotid plaques, as well as downstream micro-embolisation, may be associated with an increased risk of stroke. However, the relationship between carotid plaque ultrasound characteristics and micro-embolic signals (MES) detected in the middle cerebral artery (MCA) is still controversial. The purpose of this study was to investigate the prevalence of MES in patients with symptomatic high-grade internal carotid artery (ICA) stenosis and to identify predisposing factors, such as plaque echogenicity and intra stenotic blood flow velocity pattern. METHODS: 197 patients (mean age 69.5+/-8.6, 161 males) with confirmed symptomatic high-grade ICA stenosis and anti-platelet treatment underwent bilateral MES monitoring for 30 minutes within the anterior circulation, using Power M-mode transcranial Doppler techniques (TCD). Carotid artery plaques were characterized by Gray-Weale scaling. RESULTS: In 32.0% of the patients, we detected MES by TCD within the MCA on the symptomatic side, but the same finding was made in only 4.5% on the corresponding asymptomatic site (p<0.0001). The presence or absence of MES was associated with neither ultrasonic plaque characteristics nor the intrastenotic blood flow velocities at peak systole and end diastole. The median time since the last ischemic event symptoms was shorter in the patient group with MES [+] than in MES [-] (p=0.013). CONCLUSIONS: Despite optimum standard anti-platelet therapy, cerebral micro-embolisation occurs in 30% of patients with symptomatic carotid artery disease, which might therefore be a possible risk factor for recurrent neurological symptoms. However, the presence of MES is independent of intrastenotic blood flow disturbances and grey scale ultrasound plaque characteristics. The presence of MES as an indicator of unstable plaque and thereby a possible risk factor for stroke should be evaluated prospectively using various algorithms for plaque classifications.     

Carotid endarterectomy in patients with contralateral internal carotid artery occlusion without intraoperative shunting

BACKGROUND: Controversy about the optimal method of performing a carotid endarterectomy (CEA) exists despite its widespread application and support from various randomized clinical trials. Many surgeons selectively or routinely use electroencephalography (EEG) monitoring as well as shunting when performing this operation. ETHODS: We conducted this retrospective study to assess the maximum carotid clamp time without shunting or EEG monitoring during a CEA without the development of neurological deficits in an already compromised cerebral circulation. RESULTS: Fifteen consecutive patients who underwent CEAs between 1988 and 1999 met our criteria of angiographically documented ipsilateral internal carotid artery (ICA) stenosis with contralateral ICA occlusion. The patient presentations included asymptomatic (14%), transient ischemic attack (TIA) (50%), and stroke (36%). All patients were operated under general anesthesia without shunting and only 4 patients underwent EEG monitoring. On angiography, all 15 patients had ipsilateral ICA stenosis (70-99%) and contralateral occlusion. In 54% of patients, the vertebral arteries (VAs) were both patent, while in 46% of patients only 1 VA was patent. Eighty-five percent of patients had at least 1 patent anterior communicating (Pcomm) artery, while 15% had nonvisualized Pcomm arteries bilaterally. Of the 15 patients, 14 had a patent anterior communicating artery. The mean clamp time of the CCA was 18.5 minutes (range 14-30 minutes). None of the 15 patients had new neurological changes immediately postoperatively or during the 6 weeks of follow-up. CONCLUSION: We propose that shunting may not be necessary during CEA for high-grade stenosis with contralateral ICA occlusion, presumably because of adequate distal small vessel collaterals.     

Inability of vascular smooth muscle cells to proceed beyond S phase of cell cycle,and increased apoptosis in symptomatic carotid artery disease

OBJECTIVE: Microemboli passing through the cerebral artery downstream from high-grade carotid artery stenosis produce transient ischemic symptoms and may result in stroke. Rupture of carotid artery plaque is the main source of microemboli in high-grade internal carotid artery stenosis. However, the mechanisms underlying plaque rupture are unclear. We hypothesized that vascular smooth muscle cells (VSMC) from plaque in patients with symptoms of carotid artery stenosis undergo increased apoptosis and decreased proliferation, compared with VSMC in patients without symptoms. METHODS: VSMC were isolated by means of enzymatic dissociation from plaque removed at carotid endarterectomy in patients with symptoms of carotid artery stenosis, eg, hemispheric transient ischemic attacks, amaurosis fugax, or stroke, and patients with high-grade stenosis without symptoms. VSMC were cultured and immunostained with smooth muscle alpha-actin and caldesmon antibodies to ensure purity. TUNEL assay and annexin V labeling were performed to identify VSMC undergoing apoptosis. Proliferation assay with [(3)H] thymidine incorporation was performed in VSMC stimulated with fetal bovine serum (FBS), and cell cycle profile was analyzed with DNA staining with Vindelov reagent. RESULTS: We isolated VSMC from symptomatic plaque that showed gross ulceration, and asymptomatic plaque. Apoptosis, as measured with the TUNEL assay, in VSMC from symptomatic plaque was 5.45% +/- 0.8%, and in asymptomatic plaque was 1.20% +/- 0.2%. Annexin V labeling revealed that 26.8% +/- 3.8% cells were labeled for phosphatidylserine in VSMC in symptomatic plaque, compared with 4.8% +/- 0.3% cells in asymptomatic plaque. VSMC in asymptomatic plaque showed significantly increased uptake of [(3)H] thymidine at all concentrations of FBS, compared with symptomatic plaque. In the presence of 10% FBS, VSMC from asymptomatic plaque progressed through the S phase of the cell cycle, whereas significantly increased numbers of VSMC from symptomatic plaque were arrested in the S phase. CONCLUSION: Increased numbers of VSMC from symptomatic plaque undergo apoptosis, compared with VSMC from asymptomatic plaque. This could be due to inability of VSMC from symptomatic plaque to progress beyond the S phase of the cell cycle. Decreased proliferation and increased loss of VSMC as a result of apoptosis in symptomatic plaque may result in plaque rupture, leading to development of symptoms.     

Progression of atherosclerosis in asymptomatic carotid arteries after contralateral endarterectomy: a 10-year prospective study

OBJECTIVE: The best way to manage both symptomatic and asymptomatic severe carotid stenoses has been thoroughly demonstrated by large randomized clinical trials, but less is known about the natural history and management of the contralateral asymptomatic internal carotid artery (ICA). This prospective study was undertaken to determine whether disease progressed in the contralateral ICA of patients who had undergone carotid endarterectomy (CEA) and were followed up clinically and by duplex ultrasound (US) scan. METHODS: The contralateral asymptomatic ICAs of 599 patients who had undergone CEA for severe carotid disease over a 10-year period were followed up clinically and with duplex US scan at 1 month and then every 6 months. ICA stenosis was classified as mild (30%-49%), moderate (50%-69%), severe (70%-99%), or occlusion. Progression was defined as an increase in ICA stenosis of 50% or more for ICAs with a less than 50% baseline lesion or as an increase to a higher category if the baseline stenosis was 50% or more. End points of the study were the incidence of contralateral disease progression and late neurologic events. Kaplan-Meier analysis was used to estimate freedom from disease progression and from neurologic events. The relationship between progression and risk factors was also analyzed. RESULTS: Overall, disease progressed in 25.2% of patients (151/599) after a mean follow-up of 4.1 years. Disease progressed in 34.3% of patients (101/294) with mild stenosis vs 47.9% of patients with moderate stenosis (47/98; P = .016). Three additional patients with mild lesions at baseline progressed to severe lesions. The median time to progression was 29.8 months for mild and 18.5 months for moderate stenoses (P = .033). The rate of late neurologic events referable to the contralateral ICA was 3.2% (19/599) for the entire series and 4.8% (19/392) for patients with a 30% or greater ICA stenosis: these included 4 (0.7%) strokes and 15 (2.5%) transient ischemic attacks. All but 3 events (16.3%; 16/98) occurred in patients with disease progression from moderate to severe stenosis. Overall, 53 late CEAs were performed. CONCLUSIONS: This prospective analysis has shown that disease progression in contralateral asymptomatic ICAs after CEA is relatively common in patients with a diseased ICA at the baseline and strongly supports duplex US surveillance, approximately every 6 months, in patients with more than mild disease. A baseline lesion is significantly predictive of progression to severe stenosis, and progression from moderate to severe stenosis is strongly associated with neurologic clinical events. No demographic or clinical factor proved useful in identifying patients likely to experience disease progression.     

Comparative assessment of the results of open carotid endarterectomy and carotid aftery stenting

A comparative study of 48 carotid stent grafting and 23 open carotid endarterectomies was carried out. Patients of both groups were comparable by cerebrovascular insufficiency degree and concomitant diseases. General rate of complications after carotid stent grafting (CSG) was 5.1%. There was a small ischemic stroke with right-sided hemiparesis and aphasia in one patient during CSG. Complete regress of the neurological symptoms was seen on the 5th day. In the nearest postoperative period after CSG there was a big ischemic stroke in the territory of MCA in one patient. Rate of complications after open carotid endarterectomy (OCEAE) was 8.7% Transient ischemic attacks were seen in 2 patients in early postoperative period. Paresis of the IX cranial nerves was in one patient. In long-term postoperative period after CSG 2 patients died due to cardiac causes. One patient died 18 months after OCEAE due to ischemic stroke. In long-term period after OCEAE restenosis of the internal carotid artery was seen in 4.5% cases, while there were no restenosis after CSG. It is concluded that CSG is an effective method of treatment of carotid stenosis with lower lethality and postoperative complications rate compared with OCEAE. Indications for CSG are symptomatic stenosis of ICA (>60%), asymptomatic stenosis of ICA(>70%), two-sided lesions of the carotid arteries, carotid stenosis with lesions of other brachiocephalic arteries, insufficiency of Willis circle.     

Carotid Endarterectomy for Symptomatic,but “Haemodynamically Insignificant” Carotid Stenosis

ObjectiveCarotid endarterectomy (CEA) guidelines in symptomatic carotid stenosis are based on NASCET and ECST criteria with 70% or greater carotid stenosis as estimated from a catheter angiogram the major indication. This has several problems: (1) lack of reliable correlation between non-invasive imaging and catheter angiography, which has been largely superseded by non-invasive imaging in investigating carotid stenosis; (2) errors inherent in estimating the degree of stenosis from catheter angiography; (3) disregard for the fact that stroke risk also depends on plaque stability, and number of ischaemic events.MethodsA retrospective review of ischaemic events, imaging results, operative findings, surgical complications and stroke-free follow-up in 31 patients presenting over a 23 year period with TIA/stroke (symptoms lasting > 24 h and/or imaging evidence of infarction) who had 70% or less carotid stenosis (on non-invasive imaging), but nonetheless underwent CEA.ResultsNineteen patients had small strokes, 7 had TIAs and 5 had ocular events; 28 patients had features of unstable plaque on imaging; 19 patients experienced multiple events before CEA. All had haemorrhagic, ruptured plaque at CEA. One patient suffered an intra-operative stroke, only 1 patient suffered a further stroke/TIA (mean follow-up 4.2 years).ConclusionTo predict the likelihood of major stroke in symptomatic carotid stenosis and the benefit of CEA, plaque stability and the number of ischaemic events might be as important as an estimate of the degree of stenosis.     

Progression of asymptomatic carotid stenosis: A natural history study in 1004 patients

Purpose: The purpose of this study was to delineate the natural history of the progression of asymptomatic carotid stenosis. Methods: In a 10-year period, 1701 carotid arteries in 1004 patients who were asymptomatic were studied with serial duplex scans (mean follow-up period, 28 months; mean number of scans, 2.9/patient). At each visit, stenoses of the internal carotid artery (ICA) and the external carotid artery (ECA) were categorized as none (0 to 14%), mild (15% to 49%), moderate (50% to 79%), severe (80% to 99%), preocclusive, or occluded. Progression was defined as an increase in ICA stenosis to ≥50% for carotid arteries with a baseline of <50% or as an increase to a higher category of stenosis if the baseline stenosis was ≥50%. The Cox proportional hazards model was used for data analysis. Results: The risk of progression of ICA stenosis increased steadily with time (annualized risk of progression, 9.3%). With multivariate modeling, the four most important variables that affected the progression (P < .02) were baseline ipsilateral ICA stenosis ≥50% (relative risk [RR], 3.34), baseline ipsilateral ECA stenosis ≥50% (RR, 1.51), baseline contralateral ICA stenosis ≥50% (RR, 1.41), and systolic pressure more than 160 mm Hg (RR, 1.37). Ipsilateral neurologic ischemic events (stroke/transient ischemic attack) occurred in association with 14.0% of the carotid arteries that were studied. The progression of ICA stenosis correlated with these events (P < .001), but baseline ICA stenosis was not a significant predictor. Conclusion: In contrast to recently published studies, we found that the risk of progression of carotid stenosis is substantial and increases steadily with time. Baseline ICA stenosis was the most important predictor of the progression, but baseline ECA stenosis also was identified as an important independent predictor. Contralateral ICA stenosis and systolic hypertension were additional significant predictors. We found further that the progression of ICA stenosis correlated with ischemic neurologic events but not baseline stenosis. The data provide justification for the use of serial duplex scans to follow carotid stenosis and suggest that different follow-up intervals may be appropriate for different patient subgroups. (J Vasc Surg 1999;29:208-16.)     

Systematic review of randomized controlled trials of patch angioplasty versus primary closure and different types of patch materials during carotid endarterectomy

BACKGROUND: Patch angioplasty during carotid endarterectomy (CEA) may reduce the risk for perioperative or late carotid artery recurrent stenosis and subsequent ischemic stroke. We performed a systematic review of randomized controlled trials to assess the effect of routine or selective carotid patch angioplasty compared with CEA with primary closure, and the effect of different materials used for carotid patch angioplasty. METHODS: Randomized trials were included if they compared carotid patch angioplasty with primary closure in any patients undergoing CEA or use of one type of carotid patch with another. RESULTS: Thirteen eligible randomized trials were identified. Seven trials involving 1281 operations compared primary closure with routine patch closure, and 8 trials with 1480 operations compared different patch materials (2 studies compared both). Patch angioplasty was associated with a reduction in risk for stroke of any type (P = .004), ipsilateral stroke (P = .001), and stroke or death during both the perioperative period (P = .007) and long-term follow-up (P = .004). Patching was also associated with reduced risk for perioperative arterial occlusion (P = .0001) and decreased recurrent stenosis during long-term follow-up (P < .0001). Seven trials that compared different patch types showed no difference in the risk for stroke, death, or arterial recurrent stenosis either perioperatively or at 1-year follow-up. One study of 180 patients (200 arteries) compared collagen-impregnated Dacron (Hemashield) patches with polytetrafluoroethylene patches. There was a significant increase in risk for stroke (P = .02), combined stroke and transient ischemic attack (P = .03), and recurrent stenosis (P = .01) at 30 days, and an increased risk for late recurrent stenosis greater than 50% (P < .001) associated with Dacron compared with polytetrafluoroethylene. CONCLUSIONS: Carotid patch angioplasty decreases the risk for perioperative death or stroke, and long-term risk for ipsilateral ischemic stroke. More data are required to establish differences between various patch materials.     

Thickness of carotid artery atherosclerotic plaque and ischemic risk

Noninvasive duplex scanning of carotid artery atherosclerotic plaque was performed in 286 consecutive patients referred to a cerebrovascular diagnostic laboratory. The presence and thickness of such plaque in the region of the carotid bifurcation were examined for association with the degree of vessel stenosis, age, sex, smoking history, history of prior transient ischemic attack or stroke, and systemic manifestations of atherosclerotic disease. Atherosclerotic plaque thickness was positively correlated with degree of vessel stenosis (P less than 0.0001). Both parameters were independent predictors of cerebrovascular events but plaque thickness was a better predictor of prior transient ischemic attacks (P less than 0.05), and vessel stenosis was a better predictor of prior stroke (P less than 0.005). Patient age (P less than 0.001) and pack-years of cigarette use (P less than 0.001) were independent positive predictors of carotid atherosclerotic plaque thickness. The greatest effect of smoking and atherosclerotic plaque thickness was seen in heavy smokers younger than age 55. Both carotid artery plaque thickness and pack-years of smoking were significant independent predictors of other systemic manifestations of atherosclerotic disease (P less than 0.05). Such noninvasive scanning of carotid artery atherosclerotic plaque demonstrates the significant role of age and smoking in the progression of disease. It also suggests a significant role for carotid atherosclerotic artery plaque in the pathophysiology of cerebrovascular events, especially transient ischemic attacks, even prior to the production of a flow-limiting stenosis. Finally, noninvasive screening of carotid artery plaque may provide a useful marker for the patient at risk for systemic atherosclerotic disease and identify the patient for whom maximal atherosclerotic risk factor modification is needed.     

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.     

Carotid artery disease: clinical features and management

The most common cause of ischaemic carotid territory stroke, around 50% of cases, is thromboembolism from stenoses at the origin of the extracranial internal carotid artery (ICA). Embolism is usually preceded by acute changes in plaque morphology, which predisposes towards overlying thrombus formation and embolization. The management of patients with carotid artery disease involves cardiovascular risk factor modification, antiplatelet and statin therapy in everyone. There is grade A, level I evidence that recently symptomatic patients with 50–99% stenoses gain significant benefit from carotid endarterectomy (CEA), despite a small risk of perioperative stroke. Maximum benefit is conferred if CEA is performed as soon as possible after onset of symptoms. Carotid artery stenting (CAS) is an alternative to CEA. Excluding operative risks, 9-year rates of ipsilateral stroke are virtually identical (i.e. CAS is durable), but (at present) 30-day death/stroke is significantly higher after CAS, compared to CEA. The management of patients with asymptomatic carotid stenoses (ACS) remains controversial. The 2018 European Society for Vascular Surgery (ESVS) carotid guidelines advise that patients with a 60–99% ACS who have one or more clinical/imaging features that make them ‘higher risk for stroke’ on best medical therapy (BMT) should be considered for CEA, with the remainder being treated medically.