颈内动脉虹吸部狭窄的三维构型分析

目的 分析颈内动脉虹吸部狭窄患者与正常人在局部血管三维构型中的差别.方法 虹吸部狭窄组共29例,其中男20例,女9例,平均年龄58.6岁,吸烟者9例;对照组31例,男17例,女14例,平均年龄67.5岁,吸烟者5例.对2组病例的动脉狭窄易患因素进行统计学比较.对性别、吸烟情况进行x2检验,对动脉收缩压、血糖浓度、血脂浓度进行Student-t检验.所有狭窄组和对照组的MRA原始数据在计算机上以Mimics软件进行后处理,对虹吸部的2个弯曲在各自的平面上进行外接圆的拟合,计算拟合出来的曲率半径(ACR)的几何平均值.以配对t检验检验对照组双侧ACR之间是否存在差别.根据虹吸部狭窄的部位不同,将虹吸部狭窄组分为C2段狭窄组和C4段狭窄组.对C2段狭窄组、C4段狭窄组和对照组的ACR以多组秩和检验进行统计学比较.此外,以配对t检验对单侧C2段狭窄的患者进行狭窄侧和正常侧ACR的统计学比较.结果 虹吸部狭窄组和对照组在性别、吸烟数量的差异没有统计学意义(χ2=1.63,P＞0.05;χ2=1.86,P＞0.05).虹吸部狭窄组收缩压为(146.6±21. 3)mm Hg(1 mm Hg=0.133 kPa),对照组为(140.3±17.3)mm Hg;虹吸部狭窄组血糖浓度为(5.94±1. 89)mmol/L,对照组为(6.79±3.57)mmol/L;虹吸部狭窄组血清总胆固醇和甘油三酯水平分别为(4.57±0.87)和(1.34 ±0.63)mmol/L,对照组为(4.75±1.70)和(1.54±0.72)mmol/L,它们的差异均没有统计学意义(t值分别为1.24、1.16、0.71和1.16,P值均＞0.05).对照组中左侧ACR为(3.82±0.69)mm,右侧ACR为(4.08±1.04)mm,配对t检验显示两者之间差异无统计学意义(t=-1.44,P＞0.05).多组秩和检验显示对照组与C2、C4狭窄组3组之间的差异具有统计学意义(χ2=6.67,P＜0.05).两两比较表明在对照组和C2段狭窄组之间差异有统计学意义(t=2.63,P＜0.05),而C4段狭窄组与其他2组之间的差异无统计学意义.单侧C2段狭窄的患者中,正常侧的ACR为(3.96±1.04)mm,狭窄侧的ACR为(3.41 ±0.61)mm,配对t检验显示狭窄侧和正常侧之间有存在差异的统计学趋势(t=2.09,P=0.05).结论 颈内动脉虹吸部C2段狭窄患者的局部构型与正常人相比,具有更小的曲率半径,这意味着颈内动脉虹吸部的局部构型可能影响狭窄的发生.     

外伤性颈内动脉虹吸段假性动脉瘤的介入治疗

目的探讨颈内动脉（internal carotid artery，ICA）虹吸段假性动脉瘤血管内介入治疗的方法和疗效。方法12例外伤性ICA虹吸段假性动脉瘤，经DSA确诊后即行Willis环侧支循环功能试验，根据Willis环前、后侧支循环代偿情况采用不同的治疗方法。10例行ICA完全闭塞，1例应用电解可脱弹簧圈（GDC）填塞动脉瘤，1例未行治疗。结果12例动脉瘤中，9例行ICA闭塞后痊愈。3例脑Willis环循环功能不良，其中1例采用GDC行动脉瘤填塞治愈；1例Willis环前、后侧支循环代偿功能不良，行患侧ICA球囊闭塞（balloon test occlusion，BTO）试验30min，患者：意识、肢体活动正常，用可脱性球囊闭塞ICA，48h后死亡；1例未行栓塞，行改善侧支循环功能训练期间鼻出血死亡。结论ICA虹吸段假性动脉瘤经脑Willis环BTO试验筛选后可行ICA闭塞治疗。     

犬颈总动脉实验性虹吸段血管模型的建立

目的 探讨截取一侧颈总动脉节段与另一侧颈总动脉端端吻合建立颅底段颈内动脉（虹吸段）血管模型的可行性.方法 对8只成年家犬应用显微外科技术,将玻璃管制成“S”形,一侧颈总动脉（CCA）作为母体动脉,截取另一侧颈总动脉节段穿过玻璃管模型与对侧CCA端端吻合.2周后作血管造影（CTA/DSA）证实模型内血流通畅.结果 8只犬均成功地建成颅底段颈内动脉（虹吸段）血管模型.结论 应用犬一侧颈总动脉节段与另一侧颈总动脉端端吻合建立颅底段颈内动脉（虹吸段）血管模型切实可行.     

Routine MR imaging of the internal carotid artery siphon: angiographic correlation with cervical carotid lesions

This study correlates the appearance of the cavernous segment of the carotid artery on MR images with the presence of significant stenosis or occlusion of the cervical carotid artery as seen on angiograms in 100 patients who had brain MR imaging and arteriography within a 1-week period. Four patients demonstrated isointense signal within the carotid artery's cavernous segment; two of these findings correlated with complete carotid occlusion as seen angiographically, while partial compromise was seen angiographically in the other two. Four other patients had variable signal intensity and irregularity of the luminal outline in the carotid siphon, correlating with angiographic evidence of atheromatous disease in three patients and of dissection in one patient. The demonstration of normal signal void within a normal-appearing cavernous segment of the internal carotid artery in the remaining 92 patients correlated with absence of significant stenosis within the cervical segment in 86 patients. In the remaining six, significant disease of the internal carotid artery was found. Isointensity within the intracranial carotid artery can indicate either complete occlusion or very slow flow. Therefore, angiography is still necessary to completely exclude potentially treatable disease that produces very slow flow leading to isointensity. The presence of normal flow void in the intracranial segment does not exclude significant compromise of the cervical segment of the carotid artery.     

Direct B-mode NASCET-style stenosis measurement and Doppler ultrasound as parameters for assessment of internal carotid artery stenosis

Doppler ultrasound grading of internal carotid artery (ICA) stenosis using the two parameters of spectral analysis and internal carotid to common carotid artery peak systolic velocity (ICA/CCA PSV) ratio is well established. The improvements in B-Mode ultrasound image quality now make direct ultrasound NASCET-style stenosis measurement possible. We demonstrate that longitudinal B-mode imaging can produce accurate North American Symptomatic Carotid Endarterectomy Trial (NASCET) style measurements which have good correlation with angiographic images. Ultrasound B-mode stenosis measurement provides a third parameter which can be used in conjunction with the two Doppler parameters for the assessment of ICA stenosis. Taking the highest grade of stenosis of the three parameters produces a sensitivity of 100% for the detection of greater than 50% and greater than 80% stenosis with specificity of 66 and 90%, respectively. The performance of satisfactory B-mode imaging against digital subtraction angiography (DSA) was very encouraging. When the B-mode stenosis measurement showed a normal ICA, the positive predictive value (PPV) of the DSA being normal was 94%. When the B-mode stenosis measurement was 35% or less, the PPV of the DSA stenosis being 35% or less was 93%. These excellent results support the use of good quality B-Mode NASCET style stenosis measurement as the initial ultrasound measurement, with Doppler ultrasound only being performed when the B-mode stenosis measurement is greater than 35% or if the B-mode image is unsatisfactory. This approach would save considerable time enabling better utilization of ultrasound resources.     

Utility of covered stents for extracranial internal carotid artery stenosis

To our knowledge, the utility of coronary covered stents in the treatment of atherosclerotic carotid artery stenosis has not been defined in the English-language literature. Covered stents may prevent microembolic complications in select atherosclerotic carotid lesions, as they exclude the atherosclerotic lesion from the circulation by pressing the plaque against the vessel wall. Our early clinical experience has shown that use of these stents can be a therapeutic option in select cases of atherosclerotic stenosis of the cervical internal carotid artery.     

颈内动脉TIA患者脑动脉狭窄的分布特征

目的探讨不同年龄颈内动脉短暂性脑缺血发作（TIA）患者动脉狭窄的分布特征。方法分析研究我院收治的173例颈内动脉TIA发作患者的脑血管造影资料,将存在动脉狭窄的患者按年龄段分为青年组、中年组和老年组,对不同年龄段患者脑动脉狭窄情况进行对比研究。结果 173例中,154例（89.0%）检出存在不同程度的脑动脉狭窄;病变血管共304支,其中颅内动脉狭窄212支（69.7%）,颅外动脉狭窄92例（30.3%）,颅内动脉狭窄发生率明显高于颅外动脉（P〈0.05）。青年组以单纯颅内动脉狭窄为主,占79.3%;中年组以单纯颅内动脉狭窄和颅内、外动脉狭窄并发为主,占90.0%;老年组以单纯狭窄为主,占86.6%。3组间单纯颅内动脉狭窄发生率未见明显差异（P〉0.05）,单纯颅外动脉狭窄发生率中年组高于青年组,老年组高于中年组（P〈0.05）,中年组颅内、外动脉狭窄并存发生率明显高于青年组和老年组（P〈0.05）。结论不同年龄TIA患者脑动脉狭窄的空间分布明显不同,DSA检查有助于明确血管性病变原因。     

Overestimation of contralateral internal carotid artery stenosis before ipsilateral surgical endarterectomy

Objective

The aim of this study was to investigate a possible overestimation of the degree of contralateral carotid artery stenosis by duplex in patients with significant bilateral carotid stenoses who are to undergo carotid endarterectomy (CEA).

Methods

A retrospective analysis was performed of all patients undergoing CEA in our center over a period of 11 years. Pre- and postoperative duplex ultrasonography measurements of peak systolic velocity (PSV) and end diastolic velocity (EDV) were compared and used to classify the degree of stenosis. Univariate analysis was performed to indicate possible predictors for contralateral stenosis overestimation.

Results

A total of 384 CEA procedures in 357 patients were performed in our hospital. Pre- and postoperative bilateral duplex measurements were available in 135 patients. Forty-four out of 135 patients (33%) were preoperatively identified as having significant stenosis (>60%) of the internal carotid artery on both sides. In these patients, postoperative duplex measurements of the contralateral carotid showed a decrease in mean (SD) PSV from 2.53 (1.11) m s⁻¹ to 1.97 (0.87) m s⁻¹ (P < 0.01) and a decrease in EDV from 0.87 (0.60) m s⁻¹ to 0.60 (0.36) m s⁻¹ (P < 0.01). The absolute changes in contralateral PSV and EDV after CEA were larger among patients with a higher degree of stenosis preoperatively. These changes led to reclassification of stenosis to a lesser degree in 24 (55%) patients. In 16 cases (36%), this resulted in a measured stenosis on the contralateral side of less than 60%.

Conclusions

One-third of the patients with duplex measurements consistent with bilateral significant carotid stenosis did not have a significant contralateral stenosis by duplex after CEA. Therefore, additional postoperative duplex measurement is advisable before planning contralateral CEA.     

颈动脉狭窄的支架治疗

目的:分析探讨颈动脉支架成形术治疗颈动脉狭窄的安全性。方法:本组34例患者,在球囊扩张及支架释放过程中,全部使用保护伞,并对颈动脉狭窄程度大于70%的16例患者进行预扩张,扩张后根据狭窄长度置入自膨式支架,未扩张的18例患者直接置入自膨式支架,其中有3例未扩张的患者,支架释放后未完全膨胀,但狭窄的直径超过了80%,血流通畅,未进行后扩张。结果:支架置入成功率100%,无1例患者出现脑出血、脑梗塞等严重并发症,支架置入后,支架膨胀良好,血流通畅,患者临床症状得到明显改善。结论:颈动脉支架置入治疗颈动脉狭窄是一种新的治疗方法,亦能代替经典颈动脉内膜剥离术,并对颈动脉狭窄引起的卒中的预防和治疗发挥了重要作用。     

Evaluation of distal extracranial internal carotid artery by transoral carotid ultrasonography in patients with severe carotid stenosis

BACKGROUND AND PURPOSE: Conventional ultrasonography techniques do not allow visualization of the distal cervical segment of the internal carotid artery (ICA). In a study of patients with severe ICA stenosis, we performed transoral carotid ultrasonography (TOCU) to assess its ability to image this segment of the artery. METHODS: The study participants consisted of 20 consecutive patients who had severe carotid stenosis and who underwent carotid endarterectomy between 1999 and 2000. TOCU, conventional carotid ultrasonography, and cerebral angiography were prospectively performed before and after carotid endarterectomy. RESULTS: In all patients, the distal portion of the ICA could be clearly detected by B mode using TOCU and no plaque was observed. The diameter of the distal portion of the ICA significantly increased after carotid endarterectomy (3.9 +/- 0.5 mm [mean +/- SD]), compared with before (3.5 +/- 0.8 mm), when it was estimated by TOCU (P <.01). In seven patients, the postoperative diameter of the distal ICA increased >10%. The mean increase in the postoperative diameter was estimated to be 15.0 +/- 23.0% by TOCU, which significantly correlated with the findings (23.9 +/- 33.7%) based on cerebral angiography (P <.01). The diameter increased >10% postoperatively in 71% of the patients with the degree of cross-sectional stenosis >95% as shown by carotid ultrasonography and in 86% of the patients whose preoperative diameter was <3.0 mm. CONCLUSION: TOCU provides additional information regarding the characteristics of the distal ICA that can be obtained neither by conventional carotid ultrasonography nor by angiography.     

Intracranial carotid anastomosis and partial aplasia of an internal carotid artery

Summary A rare arterial anastomosis between the right and left internal carotid arteries at the base at the skull, with aplasia of the cervical part of the left internal carotid artery is reported. The case is unusual because, in addition to the vascular anomaly of the carotid artery, there is an aneurysm of the anterior communicating artery and bilateral renal cysts. The condition is a complex malformation syndrome caused by defective regression of the third branchial artery. Because of the characteristic angiographic aspects such a case should be called transverse carotid anastomosis.Dedicated to Professor Dr. Friedrich Loew on his 60th birthday     

Transcranial color-coded duplex sonography for detection of distal internal carotid artery stenosis

BACKGROUND AND PURPOSE: Gradation of high-grade intracranial internal carotid artery (ICA) stenosis poses a challenge to noninvasive neurovascular imaging, which seems critical for angioplasty in the ICA segments C1 and C5. We investigated cutoff values of intracranial ICA stenosis for transcranial color-coded sonography (TCCS) and compared this method with the “gold standard,” digital subtraction angiography (DSA).Materials and METHODS: Forty patients (mean age, 58.9 ± 13.8 years) with intracranial ICA lesions were prospectively examined by using TCCS and DSA. Two standard TCCS coronal imaging planes were used to evaluate the intracranial ICA. In addition, a control group of 128 volunteers without cerebrovascular disease (mean age, 48.8 ± 15.9 years) was investigated to establish standard velocity values.RESULTS: DSA confirmed 96 stenoses and 8 occlusions of the intracranial ICA in the study population. In 9% and 7% of cases, stenosis confined to the C1 or C5 segment was >50% and 70%, respectively. Receiver-operating curves demonstrated cutoff values for >70% stenosis in C1 when the peak systolic velocity (PSV) was >200 cm/s (specificity, 100%; sensitivity, 71%) or the C1/submandibular ICA index was >3 (specificity, 93%; sensitivity, 86%).CONCLUSIONS: TCCS is a reliable adjunctive method to detect and quantify significant stenosis of the intracranial ICA. The assessment of the C1/ICA index and peak systolic velocities maximizes the diagnostic accuracy of C1 stenosis to >70% when extracranial ICA stenosis coexists. Further studies need to be performed to compare the diagnostic accuracies of MR angiography and TCCS with that of DSA.

Detection of atherosclerotic narrowing of intracranial cerebral arteries is important in stroke management and aids in the identification of patients with high risk for vascular events.^1–3 Ischemic stroke due to atherosclerosis of intracranial large arteries has been reported in approximately 8%–29% of adults in general, with a higher prevalence in African and Asian populations.^4–6 The intracranial internal carotid artery (ICA) is the most common location for intracranial stenosis of >50%; such cases compose up to 49% of all intracranial artery stenoses.^1,7 Patients with severe (≥70%) intracranial stenosis have a higher risk of stroke than patients with moderate (50%–69%) intracranial stenosis.⁸ Treatment of significant stenosis relies on antiplatelet and antithrombotic agents as well as on aggressive lipid-lowering therapies.^9,10 Endovascular treatments involving angioplasty for 50%–99% ICA stenosis have also been applied but are considered experimental approaches in need of validation by controlled studies.^11–13Because the course of intracranial ICA is complicated due to its tortuosity and variability, classification of this portion of the vessel may differ between authors,^14–16 in turn complicating interpretation of the data. The “gold standard” used to assess the intracranial ICA remains digital subtraction angiography (DSA). DSA is usually performed only after noninvasive imaging procedures, such as MR angiography (MRA) and, to a lesser degree, conventional transcranial Doppler (TCD) sonography, have suggested intracranial stenosis. With TCD sonography, intracranial ICA stenosis is considered when flow velocities exceed normal values and/or exhibit abnormal flow patterns. Unlike cases of extracranial ICA disease, stenosis gradation of the intracranial ICA has not been calculated.^17,18 With MRA, intracranial ICA stenosis in the C5 as well as the C3 and C1 segments is frequently indicated by flow-void artifacts, especially when using time-of-flight sequences, because of the inherent signal-intensity loss of parallel imaging, which can only be compensated in part by the use of MR imaging contrast agents.¹⁹ Due to these MRA artifacts, calculation of ICA stenosis gradation is difficult, and semiquantitative scales, rather than percentages of stenosis, are frequently used to describe the lesion.²⁰Although the criteria for detecting significant (>50%) stenosis of basal cerebral arteries has been defined for transcranial color-coded sonography (TCCS),^21–24 little data can be found on grading intracranial ICA stenosis. The aim of this study was to elaborate the TCCS criteria for detection and quantification of significant intracranial ICA stenosis and to correlate them with conventional DSA criteria as the standard of reference.     

Treatment of restenosis after percutaneous transluminal angioplasty for internal carotid artery stenosis

The efficacy of repeated percutaneous transluminal angioplasty (PTA) and carotid endarterectomy (CEA) was examined in patients with restenosis after PTA for carotid stenosis. After percutaneous transluminal angioplasty (PTA) for 63 cases of internal carotid stenoses 13 cases of restenosis appeared. They were treated by PTA or carotid endarterectomy. The treatment was chosen by the patient after explanation of each treatment. We initially treated seven patients by repeat PTA and six by carotid endarterectomy. The degree of stenosis improved from 82 % to 30 % on average after repeated PTA. However, one patient in the PTA group had restenosis, and carotid endarterectomy was then performed. The other cases also had restenosis and were treated by PTA. The six cases treated by carotid endarterectomy were successfully treated without difficulty. The success rate of PTA was 5/7 (71 %) in the restenosis cases. Patients with a greater residual stenosis after initial PTA had significantly more frequent restenosis. Repeat PTA and CEA both appeared effective treatment for restenosis after initial PTA, although PTA had a restenosis rate similar to that of initial PTA. Received: 21 December 1998 Accepted: 21 July 1999