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.     

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 role of external carotid revascularization in the treatment of ocular ischemia

During the past 13 years, 16 patients with visual disturbances, ipsilateral internal carotid artery (ICA) occlusion, and external carotid artery (ECA) stenosis have had ECA reconstruction. Indications for operation included amaurosis fugax (AF) in five patients, AF and transient ischemic attacks in four patients, ischemic optic neuropathy in two patients, retinal artery occlusion in one patient, and blurry vision and scotomata in four patients. In 12 cases (75%), there were hemodynamically significant contralateral ICA lesions, including four contralateral ICA occlusions. EC endarterectomies were performed in 15 patients, whereas one patient was treated with a bypass graft. One transient neurologic event occurred in the perioperative period (6%). There were no deaths nor permanent neurologic deficits. Patients were followed up for periods of 1 to 60 months (mean 18.4 months). Two patients had AF postoperatively; in one instance, AF was associated with ECA thrombosis 53 months after operation. One patient had a transient ischemic attack when the ECA thrombosed 24 months after operation. This study demonstrates that visual symptoms can occur despite ipsilateral ICA occlusion. ECA revascularization is effective and can be performed with acceptable morbidity and mortality.     

Protection of anastomotic pathways to the vertebral artery during stenting of external carotid artery stenosis

A 61-year-old man presented with a severe external carotid artery (ECA) stenosis with concomitant ipsilateral internal carotid artery (ICA) occlusion manifesting as amaurosis fugax. The left ophthalmic artery was supplied from the left ECA. The left intracranial ICA was supplied by the collateral flow from the contralateral ICA and ipsilateral ECA through the ophthalmic artery. The left vertebral artery also participated in the latter collateral pathway through the left occipital artery and ascending pharyngeal artery. Percutaneous revascularization of the ECA was performed using a nitinol self-expanding stent. To prevent embolic complications through the ophthalmic or vertebral arteries, distal protection was performed using a balloon. During a 22-month follow-up period, the patient was completely free from any ocular or neurological symptoms. The present case of severe ECA stenosis with ipsilateral ICA occlusion showed that percutaneous balloon angioplasty with stenting is feasible and effective. This intervention requires cautious evaluation of the anastomotic pathways connecting the ECA to the cerebral circulation to avoid embolic complications.     

External carotid revascularization: review of a ten-year experience

In the presence of ipsilateral internal carotid artery (ICA) occlusion, external carotid artery (ECA) revascularization can improve cerebral perfusion or eliminate an embolic source. From 1974 through 1984, 37 patients at The Cleveland Clinic underwent 42 ECA reconstructions; autologous patch angioplasty and intraluminal shunting were used when feasible. Thirty procedures were limited to primary ECA revascularization, whereas 12 extended procedures were performed as reoperations after previous ECA endarterectomy or required complementary subclavian or intracranial bypass. There were no early postoperative deaths nor neurologic morbidity in the limited group, but one death, four ipsilateral hemispheric strokes, and one retinal embolism occurred in the extended group. Ten patients have died during a follow-up interval of 1 to 72 months (mean 27 months). Five late deaths were caused by myocardial infarction, only one of which was complicated by a contralateral stroke. Two additional strokes have occurred; one involved the ipsilateral and one the contralateral cerebral hemisphere. Five other patients experienced recurrent cerebral or ocular ischemic symptoms. In conclusion, extended ECA reconstruction is associated with a higher operative risk than limited revascularization. Late follow-up is necessary to detect those patients who may eventually require additional management of recurrent cerebrovascular symptoms or incidental coronary artery disease.     

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.     

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.     

Impact of external carotid artery occlusion at declamping of the external and common carotid arteries during carotid endarterectomy on development of new postoperative ischemic cerebral lesions

Objective

The external carotid artery (ECA) is inadvertently occluded during carotid endarterectomy (CEA). The importance of ECA occlusion has been emphasized as a loss of extracranial to intracranial collaterals, a source of chronic embolization, or a site for extended thrombosis during wound closure. This study aimed to determine whether ECA occlusion that inadvertently developed during endarterectomy and that was eventually detected using blood flow measurement of the ECA after declamping of all carotid arteries is a risk factor for development of new postoperative ischemic lesions at declamping of the ECA and common carotid artery (CCA) while clamping the internal carotid artery (ICA). This study also aimed to determine whether intraoperative transcranial Doppler (TCD) monitoring predicts the risk for development of such lesions.

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.     

Operative strategies in patients with symptomatic internal carotid artery occlusion

A 15-year experience with 98 patients who underwent extracranial artery reconstruction for symptomatic internal carotid artery occlusion is reviewed. Thromboendarterectomy of the occluded carotid artery resulted in unacceptably high mortality and morbidity rates, and long-term patency of the internal carotid artery was rarely achieved. Carotid endarterectomy on the side opposite the occlusion proved to be successful in relieving nonlateralizing symptoms of cerebral ischemia, whereas results were less encouraging in patients with focal symptoms in the hemisphere ipsilateral to the occlusion. External carotid artery reconstruction on the side of the occlusion was successful in relieving focal symptoms. Surgical treatment in patients with symptomatic internal carotid artery occlusion should be planned in each patient on the basis of symptoms and anatomic pattern.     

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。     

External carotid endarterectomy with internal carotid artery transposition flap angioplasty for symptomatic internal carotid artery occlusion

The external carotid artery is an important collateral pathway for cerebral perfusion when the internal carotid artery is occluded. After internal carotid artery occlusion, there is a definite risk of ipsilateral neurological events. The authors retrospectively examined their experience with endarterectomy of the external carotid artery for symptomatic internal carotid artery occlusion. Results based on the authors' experience and on historical data show external carotid endarterectomy to be a safe procedure. Obliteration of the cul-de-sac appears to be a very important factor in the prevention of reocclusion or recurrence of symptoms after external carotid endarterectomy. Use of the internal carotid artery stump for patching of the endarterectomized external carotid artery is both safe and effective in treating symptomatic internal carotid artery occlusion.     

External carotid artery shunting during carotid endarterectomy: an alternative for cerebral protection?

OBJECTIVES: to assess the application of external carotid artery (ECA) shunting in cerebral protection during carotid endarterectomy (CEA). DESIGN: prospective study. MATERIALS AND METHODS: the study comprised 137 consecutive patients who underwent CEA under locoregional anaesthesia. Transcranial Doppler was used to monitor the mean velocity of the middle cerebral artery (mv-MCA): (1) before carotid clamping; (2) after clamping both the common and external carotid arteries; (3) after clamping the internal carotid artery alone ("ECA test"). The decision to shunt was based on the occurrence of neurological deficit during carotid clamping. If the ECA test revealed mv-MCA approaching the pre-clamping values ECA shunting was used, whereas the remaining patients in need of a shunt had a standard internal carotid artery (ICA) shunt. RESULTS: shunting was necessary in 12/137 cases (9%). The ECA test indicated that in four cases - 3% of the whole series or 33% of the shunted cases. In these four patients ECA shunting reversed the neurological deficit, and CEA was successfully performed without any complications. CONCLUSIONS: ECA shunting could be considered as an alternative to standard ICA shunting. Suitable cases can be identified on the basis of the ECA test.     

Surgical therapy for recent total occlusion of the internal carotid artery

From January 1980 until May 1983, 24 patients had surgical exploration of the carotid bifurcation for suspected recent total occlusion of the internal carotid artery (ICA). All patients had recent onset of neurologic symptoms related to the ipsilateral cerebral hemisphere. Selective carotid angiography determined preoperative total occlusion of the ICA. Because surgery failed to reopen the ICA in nine patients, they had endarterectomy of the external carotid artery. Fifteen patients had initially successful thromboendarterectomy of the ICA. Prior to patient dismissal, patency was documented by B-mode ultrasound or digital subtraction angiography (DSA). All 15 patients had another B-mode ultrasound scan or DSA at least 45 days after thromboendarterectomy. On reexamination four ICAs were reoccluded, but only one patient became symptomatic. There were no operative deaths and no increase in preoperative neurologic deficits. The natural history of patients with total occlusion of the ICA is variable. The most important factor influencing a therapeutic decision is the patient's neurologic status. This study supports an aggressive, early surgical intervention for recent total occlusion in carefully selected patients.     

Jaw claudication in the era of carotid stenting

Jaw claudication could result from external carotid artery (ECA) occlusive disease. Carotid artery stenting (CAS) has been shown to worsen the disease in the ECA. This could potentially worsen the symptoms in patients with pre-existing jaw claudication undergoing CAS. Meanwhile, ECA endarterectomy is routinely done during internal carotid artery endarterectomy (CEA). This has been shown to alleviate jaw claudication symptoms. We report a case of a high-risk patient for CEA who presented with symptomatic carotid disease as well as bilateral jaw claudication. Both symptoms resolved after CEA. We also present the case of another patient treated for recurrent high-grade carotid disease with CAS resulting in acute ECA occlusion and jaw claudication. High-risk patients with symptomatic carotid disease and jaw claudication should be considered for CEA and not only CAS.     

Carotid stump syndrome: outcome from surgical management.

OBJECTIVES: in patients with occluded internal carotid arteries the carotid stump is a potential source of microemboli resulting in the persistence of retinal or cerebral ischaemic symptoms. We report 25 patients who had persistent cerebral and retinal ischaemic symptoms with an occluded ipsilateral ICA and a carotid stump who underwent surgical exclusion of the stump. METHODS: between January 1988 and January 1998, 332 patients underwent carotid endarterectomy. Twenty-five patients (20 males: five females; mean age 58.9 (range 44-78 years)) had carotid stump exclusion. Indications for surgery were transient ischaemic attack (22), amaurosis fugax (eight) and cerebrovascular accident (13). Three patients had undergone contralateral carotid endarterectomy and 12 had significant contralateral stenosis. Twenty patients were being treated with aspirin and four with warfarin at the time of presentation. RESULTS: the diagnosis of carotid stump was made in 22 patients by angiography. In the remaining three patients duplex alone was diagnostic in two patients. In the third case duplex was combined with magnetic resonance angiography (MRA) to confirm the diagnosis. Stump exclusion was carried out by oversewing the ICA origin. All but one patient remained symptom free at follow-up. CONCLUSION: carotid stump syndrome should be considered as a likely clinical entity in patients with an occluded ICA and persisting cerebral and retinal microembolic symptoms. Surgical exclusion of the carotid stump is a safe and effective method of treatment.     

Correlation of postoperative and two-year follow-up angiography with neurological function in 99 carotid endarterectomies in 86 consecutive patients.

Eighty-six consecutive patients in 1982 underwent 99 endarterectomies and routine postoperative digital subtraction angiography. Ten vessels were closed primarily and 89 with a patch graft. Minor morbidity was 2%, major morbidity 0%, and mortality 1%, but these varied according to the patient's preoperative medical and neurological function and angiographic findings. Postoperative patency for the common carotid artery (CCA) and internal carotid artery (ICA) was 100% and for the external carotid artery (ECA) 97%. Seventy-nine vessels were evaluated by a DSA 2 years after surgery. There was one asymptomatic occlusion in follow-up and one symptomatic re-stenosis in a patient with a proven heparin induced hypercoagulability state. The three postoperative ECA occlusions were associated with a lethal postoperative stroke, the only ICA occlusion in follow-up, and a 50% stenosis of the CCA in follow-up at the site of ECA occlusion. Vein patch grafting protected the ICA but not the CCA from recurrent stenosis. The carotid slim sign on preoperative angiograms is judged to indicate a patient at high risk of stroke morbidity.     

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.     

Ventromediale Lagevariante der A. carotis interna

Anatomy and geometry of the carotid bifurcation are extremely complex. Medial and ventromedial positions of the internal carotid artery (ICA) account for approximately 6%. This is not rare enough that technical problems related to carotid TEA would not be encountered. However, medial and ventromedial positions of the ICA in combination with a high carotid bifurcation with implications for carotid endarterectomy are extremely rare. Three cases (two women and one man, mean age: 70 years) with symptomatic ICA stenosis and medial or ventromedial position of the ICA underwent carotid thrombendarterectomy (TEA). In two patients conventional TEA without sacrificing the ECA was not feasible. A “medial” eversion TEA was performed. The third patient with medial position of the ICA and low position of the carotid bifurcation underwent conventional TEA with patch plasty. In a few cases a medial and ventromedial position of the ICA may require a modified technical procedure. “Medial” carotid eversion TEA can easily be performed in these cases.     

Ischemic events due to intraoperative microemboli developing in the cerebral hemisphere contralateral to carotid endarterectomy in a patient with preoperative cerebral hemodynamic impairment

A 74-year-old man with a history of asymptomatic right internal carotid artery (ICA) occlusion experienced amaurosis fugax in the left eye. Angiography showed left cervical ICA stenosis in addition to right cervical ICA occlusion. The right anterior and middle cerebral artery (MCA) territories were perfused from the left ICA via the anterior communicating artery. Brain perfusion single-photon emission computed tomography revealed reduced cerebral blood flow and reduced cerebrovascular reactivity to acetazolamide only in the right cerebral hemisphere. The patient underwent left carotid endarterectomy (CEA). Transcranial Doppler monitoring showed microembolic signals in the left MCA during dissection of the left ICA, but intraoperative monitoring suggested absence of global hypoperfusion or ischemia in the bilateral cerebral hemispheres during left ICA clamping. Transient and slight motor weakness of the left upper extremity was noted on recovery from anesthesia. Diffusion-weighted magnetic resonance imaging demonstrated the development of new spotty ischemic lesions only in the right cerebral hemisphere. The present case suggests that intraoperative cerebral embolism causing postoperative neurological deficits can develop exclusively in the cerebral hemisphere contralateral to CEA if the hemisphere has preoperative hemodynamic impairment and collateral circulation via the anterior communicating artery from the ICA ipsilateral to CEA.