External carotid artery revascularization: indications, operative techniques and results.

The external carotid artery (ECA) is an important collateral pathway in patients with ipsilateral internal carotid artery (ICA) occlusion and recurrent symptoms. An ipsilateral ECA revascularization can improve cerebral perfusion or eliminate an embolic source. In the past 11 years 11 patients underwent operation, 6 times for amaurosis fugax and 5 times for transient ischaemic attacks. Eight times ECA endarterectomy was performed for stenosis and/or ulceration. Eight times closure or separation of the ICA stump with thrombus was carried out. There were no perioperative neurological deficits or deaths, with the exception of 3 patients who already had a long-standing deficit due to the ICA occlusion. All patients were relieved of their ocular or hemispheric symptoms in a follow-up period of 8 years. Two late strokes occurred after 1 1/4 and 4 years. Ipsilateral ECA revascularization is an effective and safe operation and has good long-term results.     

Internal carotid artery stenosis and external carotid artery occlusion with unusual extracranial collateral pathway: case report

A patient with stenosis of the internal carotid artery and occlusion of the external carotid artery associated with an unusual extracranial collateral pathway is presented. A 63-year-old man was hospitalized for sudden onset of black-out after urination. He was alert, and no neurological deficit was found. MRI showed multiple lacunae in the bilateral putamens. Cerebral angiogram demonstrated severe stenosis of the left internal carotid artery at its cervical segment and complete occlusion of the left external carotid artery at its origin. The ascending pharyngeal artery originated from the left internal carotid artery above its stenotic lesion and the superior thyroid artery originated from the left common carotid artery. The sternocleidomastoid branch from the left superior thyroid artery and the muscular branch from the left vertebral artery anastomosed with the muscular branch of the ascending pharyngeal artery. The ascending pharyngeal artery maintained patency of the internal carotid artery. It is important to perform vertebral angiography when there is proximal occlusion and severe stenosis of the internal carotid artery, and when the ascending pharyngeal artery has not been clearly identified as a branch from the ipsilateral external carotid artery on the common carotid angiogram.     

The haemodynamic value of external carotid artery collateral blood supply in carotid artery disease

In the presence of severe obstruction of the internal carotid artery (ICA) blood supply to the ipsilateral hemisphere may be provided by collaterals. Whereas the circle of Willis in many cases makes a substantial contribution to cerebral perfusion, the value of collateral blood supply originating from the external carotid artery (ECA) is not clear. In thirty-five patients undergoing carotid endarterectomy (24 with proven external carotid artery collaterals) intra-arterial blood pressures were measured across the ICA stenosis, prior to endarterectomy. In order to evaluate the haemodynamic value of ECA collaterals, the distal ICA pressure was measured with and without the ECA clamped. In addition, volume blood flow in the common carotid artery was measured with and without the ECA clamped, before and after endarterectomy. No significant change in distal ICA pressure was observed when the ECA was clamped, whether or not external carotid artery collaterals had been demonstrated preoperatively. The greatest reduction in mean distal ICA pressure observed upon ECA clamping was 8 mmHg. However, this only occurred in three of 11 patients with a severe pressure reduction across the stenosis. ICA blood flow increased significantly following endarterectomy whereas ECA flow was reduced. This study indicates that ECA collaterals in most cases do not contribute substantially to cerebral perfusion. Endarterectomy of the ECA, in order to improve cerebral circulation, seems justified only in selected cases, where the distal ICA pressure has been shown to be severely reduced.     

Transcranial Doppler ultrasound in internal carotid artery and middle cerebral artery disease

Using noninvasive transcranial Doppler sonography, we studied cerebral collateral patterns in 30 patients with stenosis and/or occlusion of the extracranial internal carotid artery (ICA). All patients with unilateral ICA stenosis ⩽ 80% had normal transcranial Doppler findings. 80% of patients with unilateral and 50% of patients with bilateral ICA stenosis of more than 80% including those with occlusion showed a collateralization via the ipsilateral anterior and/or posterior cerebral artery. 20% of patients with unilateral and 50% of patients with bilateral ICA stenoses of more than 80% (including occlusion) had two or three collateral pathways, including the ophthalmic artery. Another ten patients with stenosis or spasm of the middle cerebral artery (MCA) showed increased flow velocities with turbulence in the narrow segment. In four patients with severe MCA disease with a systolic peak velocity of more than 200 cm/s, the Doppler waveform distal to the lesion was damped. Decreased regional cerebral blood flow (rCBF) measured by^99mTc-HMPAO-SPECT was found in two patients with severe MCA stenosis. Another patient with moderate MCA stenosis with a systolic peak velocity of 140 cm/s showed a normal cerebral perfusion pattern.     

The role of external carotid endarterectomy in the treatment of ipsilateral internal carotid occlusion: collective review

Complete occlusion of the internal carotid artery (ICA) may result in a variety of clinical states. Neurologic symptoms in the setting of ICA occlusion may be due to embolic events through the external carotid artery (ECA) circulation, hemodynamic insufficiency resulting from inadequate collateral development, or propagation of clot intracranially. External carotid reconstruction has been used to prevent neurologic events from the first two mechanisms. This review attempts to place in perspective the current indications for, techniques of, and results from ECA revascularization. A discussion of the cerebral collateral circulation is included for reference. Twenty-three series were collected from the literature. Cases were excluded in which procedures other than ECA reconstruction were undertaken, leaving 218 cases for analysis. These represented 195 EC endarterectomies and 23 ECA bypasses. Resolution of symptoms was seen in 83% of patients with another 7% showing marked improvement. The perioperative mortality rate was 3%; neurologic deaths accounted for most perioperative deaths. The overall neurologic complication rate was 5%. More recent reports were notable for improved mortality and morbidity. A diseased contralateral carotid artery was associated with higher neurologic morbidity whereas disease in the vertebral arteries had no impact on outcome. The best results were obtained when surgery was performed to relieve specific hemispheric or retinal symptoms as opposed to nonspecific neurologic complaints or previous stroke. The symptomatic patient with ICA occlusion has a poor neurologic prognosis. In selected circumstances ECA reconstruction should be considered among the treatment options in this clinical setting.     

Vidian artery as a collateral channel between the external and occluded internal carotid arteries--case report--

A 68-year-old man presented with occlusion of the internal carotid artery (ICA) manifesting as a 6-month history of progressive sensory and motor disturbance of the left lower limb. Angiography clearly demonstrated a collateral arterial network between the ICA and external carotid artery (ECA) through the vidian artery, a small branch of both the ICA and ECA. The vidian artery may form an unusual but important ECA-ICA collateral pathway in patients with occlusive lesion of the ICA.     

External carotid endarterectomy in the treatment of symptomatic patients with internal carotid artery occlusion

In patients with internal carotid artery (ICA) occlusion, the external carotid artery (ECA) can be both a source of collateral flow and a pathway for emboli. We identified 11 patients with ICA occlusion and ipsilateral ECA stenosis who underwent ECA endarterectomy to determine its role in treating extracranial cerebrovascular disease. Follow-up ranged from 1–65 months, with a mean of 27 months. Seven of eight patients with unilateral disease remained symptom free. The eighth patient had recurrent symptoms that were subsequently diagnosed as hemi-Parkinsonism. Two of three patients with bilateral occlusive disease had developed non-hemispheric symptoms at 12 and 24 months, respectively; the third remains asymptomatic after extracranial-intracranial bypass. None of the seven patients who presented with amaurosis fugax had recurrent visual symptoms. ECA endarterectomy is a safe and effective operation in treating symptomatic patients with ICA occlusion, especially those with transient monocular blindness or unilateral occlusive disease. It is less effective in those patients who have diffuse bilateral occlusive disease.     

The contribution of the external carotid artery to cerebral perfusion in carotid disease

PURPOSE: In the presence of carotid occlusion, the external carotid artery (ECA) becomes an important source of cerebral blood flow, especially if the circle of Willis is incomplete. The contribution of the ECA to hemispheric blood flow in patients with severe ipsilateral carotid stenosis has never been previously investigated. METHODS: One hundred eight patients were monitored during sequential cross-clamping of the external (ECA) and then ipsilateral internal carotid artery (ICA) during carotid endarterectomy using transcranial Doppler sonography (TCD) (Neuroguard CDS, Los Angeles, Calif), to measure middle cerebral artery blood flow velocity, and near-infrared spectroscopy, to measure regional cerebral oxygen saturation (CsO(2)) (Invos 3100A; Somanetics, Troy, Mich). RESULTS: On the ipsilateral ECA cross-clamp, the median fall in CsO(2) was 3% (interquartile range, 1%-4%; P <.0001). On addition of the ICA cross-clamp there was a further fall of 3% and a total fall of 6% (3%-9%; P <.0001). The median percentage fall in middle cerebral artery blood flow velocity on ECA clamping was 12% (4%-24%; P <.0001); on ICA clamping it was 48% (25%-74%; P <.0001). Falls in TCD on ECA clamping were greater with increasing severity of ipsilateral ICA stenosis. The correlation between CsO(2) and TCD on external clamping, although less strong than that on internal clamping, was statistically significant r = 0.32; P =.01; Spearman rank correlation). CONCLUSIONS: The falls in TCD and CsO(2) were of a similar order of magnitude and must therefore reflect a fall in cerebral perfusion. The ipsilateral ECA contributes significantly to intracranial blood flow and oxygen saturation in severe carotid stenosis.     

Transvascular treatment of giant aneurysms of the cavernous carotid and vertebral arteries: Functional investigation and embolization

Functional angiographic investigation and percutaneous embolization using detachable balloons in nine carotid cavernous aneurysms, three petrous aneurysms, one vertebral artery aneurysm, and one posterior inferior cerebellar aneurysm are reported. A double-lumen balloon catheter is used to evaluate acute tolerance to occlusion of the carotid or vertebral arteries. Occlusion is tested under systemic heparinization. Local perfusion of heparinized saline, proximal as well as distal, to the balloon occlusion is used. The procedure was successful in all but one cavernous aneurysm. The arterial lumen was sacrificed in all cases. Clinical improvement occurred in all successful cases. Retroorbital pain was relieved in all. Ocular cranial nerve palsies improved or resolved in most. One delayed ophthalmic episode that improved represents the only complication. No such embolic problems occurred in any case in which the cavernous carotid artery was occluded by balloon trapping. The delayed embolic complications after carotid artery occlusion are related to the collateral vessels to the C-4 and C-5 segments of the artery. Balloon trapping decreases the length of the thrombosed segment and prevents retrograde filling of the aneurysm.     

Cerebral hemodynamics in patients with carotid artery occlusion and contralateral moderate or severe internal carotid artery stenosis

OBJECT: The purpose of this study was to evaluate cerebral hemodynamics in patients suffering from occlusion of the carotid artery (CA) and contralateral CA stenosis. METHODS: Using transcranial Doppler ultrasonography, the cerebrovascular reactivity to hypercapnia in the middle cerebral arteries was evaluated by calculating the breath-holding index (BHI) of 69 symptomatic patients suffering from internal CA (ICA) occlusion and moderate or severe contralateral ICA stenosis. To evaluate which variables influenced BHIs ipsilateral to the site of ICA occlusion, a multiple stepwise linear regression analysis was performed that included the following factors: patient age, percentage of contralateral ICA stenosis, contralateral BHI, number of collateral pathways, and presence of hypertension, diabetes, smoking, and hyperlipidemia. An analysis of variance was conducted to evaluate the impact of the type of collateral vessels on the BHI. A regression analysis showed that the BHI ipsilateral to the site of ICA occlusion could be accounted for by the contralateral BHI (which was entered at the first step of the analysis, p < 0.001) and by the number of collateral pathways (which was entered at the second step, p = 0.033). Neither the degree of contralateral ICA stenosis nor the other variables could be added to improve the model. The analysis demonstrated that the absence of collateral pathways and the presence of the anterior communicating artery (ACoA) alone were associated with lower BHI values than those found in the presence of two or three collateral vessels, regardless of the presence of an anterior collateral pathway. CONCLUSIONS: On the basis of these data one can infer that the cerebral hemodynamic status of patients with occlusive disease of the CA is influenced by individual anatomical and functional characteristics. Because improvement in contralateral hemodynamics after surgical correction of an ICA stenosis can only be expected in the presence of an ACoA, the planning of strategies for influencing cerebral blood flow distal to an ICA occlusion and, in particular, the consideration of a contralateral carotid endarterectomy, should be preceded by a careful evaluation of the intracranial hemodynamic adaptive status of the patient. Particular attention should be paid to cerebrovascular reactivity and the number and type of collateral vessels that are present.     

Proximal ligation of the parent artery for symptomatic tandem stenosis of the extradural internal carotid artery: a case report

A 72-year-old man suffered blindness due to right central retinal artery occlusion. Cerebral angiography revealed tandem stenosis in the cervical, petrosal and cavernous portions of the right internal carotid artery (ICA). Blood flow from the vertebrobasilar artery via the right posterior communicating artery mainly perfused the right cerebral hemisphere. In addition, significant stenosis was observed in the left cervical carotid artery and the origin of the left vertebral artety. First, the patient underwent left carotid endarterectomy and vertebral artery to subclavian artery transposition. Two months later, ligation of the right ICA at its origin was performed. Postoperative course was uneventful and the patient has not experienced further ischemic events. We suggest that proximal ligation of the parent artery is a useful procedure for medically-refractory extradural ICA stenosis when surgical direct revascularization and percutaneous transluminal angioplasty cannot be performed.     

Effect of carotid artery stenting on the external carotid artery

OBJECTIVE: We studied the fate of the ipsilateral external carotid artery (ECA) after stenting of the internal carotid artery (ICA) compared with the contralateral ECA. SUBJECTS AND METHODS: One hundred twenty-one ipsilateral ECAs in 112 consecutive patients who underwent carotid artery Wallstent placement were prospectively studied with color-coded duplex sonographic scanning (CCDS) and compared with 83 contralateral ECAs over 2 years. CCDS was scheduled for the day before (day 0), the day after (day 1) and 3, 6, 12, and 24 months after stenting. Development of ECA occlusive disease was evaluated with ECA-common carotid artery flow ratio (peak systolic velocity). For estimation of ECA stenosis 70% or greater, flow ratio 4.1 was used as the cutoff point. RESULTS: Before and after stenting, two and three (one additional) ECA occlusions were seen. Median grade of ECA stenosis on day 1 did not significantly change at angiography (P = 1.0; tendency of increase) or CCDS (P =.27; tendency of decrease).At follow-up (day 1-24 months, CCDS only), frequency of stenosis 70% or greater in the ipsilateral ECA was 21 of 120 (17.5%) on day 1 and 41 of 107 (38.32%) at 24 months, and 3 of 107 (2.5%) and 5 of 107 (4.67%) ECA occlusions were registered at the two time points. Progression of disease, as demonstrated by increase in flow ratio over time, was much more pronounced in the ipsilateral ECAs compared with the contralateral ECAs (P =.0002).In stented ICA, 2 (1.85%) asymptomatic recurrent stenoses 70% or greater were found at CCDS.One of three patients with new ECA occlusions reported jaw claudication for 10 days. Perioperative stroke (one major, four minor) occurred in 5 of 121 patients (4.46%). Two minor strokes caused by embolization occurred during the first year. CONCLUSION: The more pronounced progression of arteriosclerotic disease at the orifice of the ipsilateral ECAs during the first year after carotid stenting might be due to local factors of the ICA stent. Its clinical significance in respect to the effect of the ECA as collateral supply to the brain might depend on the incidence of carotid stent rerecurrent stenosis, which was low in the present study.     

Ruptured dissecting aneurysm of the vertebral artery associated with occlusive internal carotid artery dissection--case report

A 64-year-old male presented with subarachnoid hemorrhage. Angiography showed a dissecting aneurysm of the right vertebral artery (VA), and severe stenosis of the right internal carotid artery (ICA). He was treated conservatively in the early stage. Repeat angiography showed enlargement of the dissecting aneurysm of the VA and partial resolution of the stenosis of the right ICA. Intraaneurysmal coil embolization with proximal coil occlusion was performed following a balloon occlusion test. The postoperative course was uneventful. Based on the neuroradiological findings, the stenotic lesion of the right ICA was considered to be due to dissection. Analysis of serial changes in dissecting lesions in the craniocervical arteries is important for the correct choice of treatment, especially in patients with multi-vessel dissections. The surgical options should be determined on an individual basis.     

Local intraarterial fibrinolysis in central retinal artery occlusion: case report

The authors report a case of local intraarterial fibrinolysis (LIF) in central retinal artery occlusion (CRAO). A 79-year-old man with stenosis of the left internal carotid artery (ICA) suffered sudden loss of vision in his left eye. LIF was carried out using a microcatheter in the origin of the ophthalmic artery on the side of the CRAO. Treatment was performed with 120,000 IU of urokinase. After LIF, marked improvement of vision was established. No complication occurred during LIF. One month later, carotid artery stenting was performed for the left ICA stenosis. We consider LIF in CRAO is effective treatment.     

Management of internal carotid artery occlusion

Although attempts to restore patency of occluded internal carotid arteries are now rarely made, endarterectomy in the contralateral artery, external carotid endarterectomy and until recently EC/IC bypass have remained surgical options in the management of such patients. Over a four-year period at this institution 104 patients underwent carotid endarterectomy for stenosis. In this group the contralateral carotid was patent (Group A). Fifty-four patients with unilateral carotid artery occlusion underwent contralateral endarterectomy (Group B), 8 underwent ECA/ICA bypass (Group C) and 4 an ECA endarterectomy (Group D). No statistically significant difference was noted in perioperative stroke and death rates for Groups A and B were (1% and 1%) and (3.7% and 1.9%) respectively. One Group C patient died from perioperative stroke (12.5%). For late events the life table adjusted annual rates for stroke and mortality were similar, Group A (stroke 2.1% and death 5%), and Group B (stroke 1.6% and death 5%). In Group C stroke rate was 10% and death 3%. All four patients undergoing ECA endarterectomy were relieved of their symptoms. It is concluded that in patients with internal carotid artery occlusion TEA may be performed with perioperative morbidity and mortality rates comparable to those when the opposite carotid artery is patent. The late outcome for stroke compares favorably with the reported natural history of the disease and outcome for such patients treated medically in the Joint Study of Extracranial Occlusion and EC-IC Bypass Study. External carotid artery endarterectomy appears useful in the treatment of embolic events on the occluded side. ECA/ICA bypass does not appear to confer benefit.     

Carotid artery stenting using the proximal or dual protection method for near occlusion of the cervical internal carotid artery

The treatment for patients with near occlusion of the cervical internal carotid artery (ICA) is controversial. The aim of this study was to examine the results of carotid artery stenting (CAS) as a surgical treatment for ICA near occlusion. Between April 2008 and September 2012, 14 patients (all men; mean age, 75.4 years) with ICA near occlusion were treated with CAS. This represents 5.2 % of a total of 267 patients treated with CAS during the study period. All patients were treated with CAS using an embolic protection device. The proximal balloon protection method was performed in five patients, and the dual protection method using a proximal balloon and distal filter protection was used in nine patients. We examined the change of stenotic lesion, hyperintensity spot in diffusion-weighted imaging (DWI), and perioperative complications after CAS. All near occlusions were successfully dilated. Among 2 of 14 patients, DWI showed 1 and 4 hyperintensity spots. Transient and persistent complications, including neurological deficits, did not occur in any patients. In this small number of cases, CAS using the proximal or dual embolic protection method seems to be a safe and beneficial treatment for ICA near occlusion.     

Internal carotid and ipsilateral type II proatlantal artery stenoses causing simultaneous hemispheric and vertebrobasilar transient ischemia

A case of persistent proatlantal artery (PA) is described in a 60-year-old woman who presented with cerebellar ataxia, homonymous hemianopia, and aphasia. Both Doppler scan and magnetic resonance angiography (MRA) showed agenesis of both vertebral arteries, 80% stenosis of the left internal carotid artery (ICA), and an anastomotic vessel between the left external carotid artery (ECA) and the left vertebral artery (LVA) with a tight stenosis at the origin. It was thought to be a type II PA. Both lesions were successfully treated by ICA endarterectomy and common carotid artery to PA bypass. This case demonstrates the clinical significance of persistent PA in the evolution of an ischemic cerebrovascular disease.     

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 angioplasty with internal carotid artery flow reversal is well tolerated in the awake patient

OBJECTIVE: The purpose of this study was to evaluate the neurologic tolerance and changes in ipsilateral hemispheric oxygen saturation during transcervical carotid artery stenting with internal carotid artery (ICA) flow reversal for embolic protection. PATIENTS AND METHODS: This was a prospective study of 10 patients (mean age 68 years) undergoing transcervical carotid angioplasty and stenting. All ICA stenoses were greater that 70%. Seven patients had an ipsilateral hemispheric stroke (3) or transient ischemic attack (4), two patients had a contralateral stroke, and one patient was asymptomatic. Nine procedures were done under local anesthesia. Cerebral protection was established through a cervical common carotid (CCA) cutdown to create an external fistula between the ICA and the internal jugular vein with temporally CCA occlusion. Venous oxygen saturation (SVO(2)) was continuously monitored through a catheter placed in the distal internal jugular vein. Mental status and motor-sensory changes were categorized and assessed throughout and after the procedure. RESULTS: All procedures were technically successful without significant residual stenosis. Mean ICA flow reversal time was 22 minutes (range, 15 to 32). Common carotid artery (CCA) occlusion produced a slight (SVO(2) = 72.6%+/-9.4) but significant decrease (P =.012) in SVO(2), compared with baseline (SVO(2) = 77% +/-10.5). During ICA flow reversal (SVO(2) = 72.4% +/-10.1) cerebral oxygen saturation did not change compared with CCA occlusion alone (P =.85). Transient balloon occlusion during angioplasty of the ICA (SVO(2) = 64.6%+/-12.9) produced a significant decrease in cerebral SVO(2) compared with CCA occlusion (P =.015) and compared with CCA occlusion with ICA flow reversal (P =.018). No mental status changes or ipsilateral hemispheric focal symptoms occurred during CCA occlusion with ICA flow reversal. One patient with contralateral ICA occlusion sustained brief upper extremity weakness related to the contralateral hemisphere. Five patients sustained a vasovagal response during balloon dilatation, four did not require treatment, and one had asystole requiring atropine injection. Mean SVO(2) saturation was not different in these five patients compared with the five who did not sustain a vasovagal response. No deaths or neurologic deficits occurred within 30 days after the procedure. CONCLUSIONS: Our data suggest that transcervical carotid angioplasty and stenting with ICA flow reversal is well tolerated in the awake patient, even in the presence of symptomatic carotid artery disease. Cerebral oxygenation during ICA flow reversal is comparable to that during CCA occlusion. ICA angioplasty balloon inflation produces a decrease in cerebral SVO(2) significantly greater than that occurring during ICA flow reversal.     

Carotid Endarterectomy for Vertebrobasilar Insufficiency Caused by Severe Stenosis of Primitive Hypoglossal Artery: A Technical Case Report and Literature Review

Persistent primitive hypoglossal artery (PHA) originating from the external carotid artery (ECA) is a rare anomaly. Reports of carotid endarterectomy (CEA) for ECA stenosis associated with this anomaly are even rarer. A 76-year-old woman presented to a medical clinic with a major complaint of refractory dizziness. Carotid ultrasound study suggested severe stenosis of the left cervical carotid bifurcation; therefore, she was referred to our department for a possible CEA. The imaging results indicated severe stenosis of the left carotid bifurcation and that the ECA was a PHA and the origin of the dominant vertebrobasilar artery (VBA). CEA was performed with the special caution of providing VBA collateral flow during clamping and preventing microembolisms during declamping of the ECA. Postoperative head magnetic resonance imaging revealed no new findings of cerebral infarction, and her dizziness disappeared. CEA associated with stenosis of the PHA as the origin of a dominant VBA was safely performed with an appropriate understanding of possible collateral pathways during cross-clamping.