The treatment of cerebral ischemia by external carotid artery revascularization

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.

Staged Cerebral Revascularization in a Patient With an Occluded Common Carotid Artery

Background and Purpose— We report a management strategy for cerebral revascularization in a patient with an occluded common carotid artery by first performing a subclavian to external carotid artery bypass, followed by superficial temporal artery middle cerebral artery (STA-MCA) bypass.

Methods— The patient presented with symptomatic left hemispheric hemodynamic insufficiency, associated with occlusion of the ipsilateral internal and common carotid arteries. The STA was not detectable. The patient was treated initially with a subclavian to external carotid artery bypass, with partial improvement in symptoms.

Results— Angiography demonstrated improvement in perfusion and STA filling, which was used for STA-MCA bypass, with resolution of symptoms.

Conclusion— Our experience with this case has led us to consider a staged approach for management of patients with an occluded common carotid artery.

Thyrocervical trunk—external carotid artery bypass for positional cerebral ischemia due to common carotid artery occlusion

✓ Medically refractory positional cerebral ischemia (PCI) and concomitant orthostatic hypotension associated with chronic common carotid artery (CCA) occlusion are rare. In this technical report, the authors describe an extracranial bypass in which the thyrocervical trunk was used as a donor vessel to treat three cases of CCA occlusion with PCI. Postoperatively, although orthostatic hypotension remained, ischemia-related symptoms resolved in all three patients and long-term graft patency was demonstrated. It is possible to treat cerebral ischemia due to CCA occlusion with extracranial bypass surgery. In these patients, the thyrocervical trunk proved to be a suitable donor vessel for the reconstitution of blood flow within the external carotid artery.

Thyrocervical trunk–external carotid artery bypass for positional cerebral ischemia due to common carotid artery occlusion

Medically refractory positional cerebral ischemia and concomitant orthostatic hypotension associated with chronic common carotid artery (CCA) occlusion are rare. The authors detail their experience with three cases treated exclusively by an extracranial bypass in which the thyrocervical trunk was used as the donor vessel. Postoperatively grafts were patent and symptoms resolved in all three patients, although orthostatic hypotension remained. Postural cerebral ischemia due to CCA occlusion can be treated by extracranial bypass surgery. The thyrocervical trunk is a suitable donor for reconstruction of the external carotid artery in these cases.

External carotid endarterectomy for amaurosis fugax in the presence of internal carotid artery occlusion

Two patients with occlusion of the internal carotid artery who were experiencing repeated episodes of transient monocular blindness in the ipsilateral eye were successfully treated with external carotid endarterectomy. The mechanisms for the production of symptoms in the presence of an internal carotid occlusion are discussed, including the anatomical pathways for embolization through collaterals between the internal and external carotid arteries. The indications, technique and results of external carotid endarterectomy are reviewed.

Extrathoracic bypass procedures for proximal common carotid artery lesions

During a 10-year period ending in December 1991, 31 extrathoracic bypass procedures were performed in 29 patients for proximal common carotid artery atherosclerotic stenosis or occlusion. This included 16 men and 13 women, with a mean age of 63 years. Indications for surgery included transient ischemic attacks in 23 patients (79%), nonfocal symptoms in 4 patients (14%), and asymptomatic proximal common carotid artery stenosis associated with near-total occlusion of the internal carotid artery in 2 patients (7%). Severe proximal stenosis or complete occlusion of the common carotid artery was demonstrated angiographically in all cases. Subclavian-to-carotid bypass was performed in 26 cases and carotid-to-carotid bypass in 5 cases. Seventy-four percent of the bypass procedures were to the common carotid artery and 26% to the external carotid artery. Endarterectomy of the common carotid bifurcation was performed in conjunction with the bypass procedure in 13 cases and vertebral artery transposition in 2 other cases. Saphenous vein was used as the bypass conduit in 65% and prosthetic grafts in 35% of cases. There were no perioperative strokes or deaths in this series, and the mean postoperative hospital stay was 5 days. Follow-up ranged from 2 to 118 months (mean: 38.4 months). Graft occlusion occurred in two cases during the follow-up period (3-year patency rate: 90%), with recurrence of symptoms in one patient, which necessitated revision. Three patients had persistence or recurrence of symptoms despite patency of the graft, one other patient sustained a posterior circulation infarct, and there was one death unrelated to carotid vascular disease during the follow-up period. This experience shows that extrathoracic bypass procedures are safe and well tolerated for symptomatic proximal common carotid artery stenosis or occlusion. This method of reconstruction has excellent long-term patency and protection against further anterior circulation neurologic events.

Is there a conduit of preference for a bypass between the carotid and subclavian arteries?

The conduit of choice for a bypass between the carotid and subclavian arteries remains controversial. We retrospectively evaluated 32 patients who underwent bypass between the carotid and subclavian arteries. Perioperative mortality was limited to a single patient who sustained a myocardial infarction. Long-term follow-up (mean: 46 months) revealed an 87% stroke-free survival rate, a 74% neurologic symptom-free survival rate, and a 77% primary patency rate at 5 years. No overall difference was discerned between a prosthetic or autogenous vein conduit. However, in bypasses constructed from the subclavian artery to the level of the carotid bifurcation, 100% (nine of nine) of vein bypasses remained primarily patent compared with 40% (two of five) of prosthetic grafts (p < 0.05). No distinct patency difference was identified between a short vein or a prosthetic bypass constructed between the proximal common carotid artery and subclavian artery. A vein bypass results in superior patency compared with a prosthetic graft for longer bypasses constructed from the subclavian artery to the carotid artery bifurcation.

An external carotid artery shunt to prevent cerebral ischaemia during carotid surgery

The contribution of the external carotid artery to cerebral blood flow in the presence of an internal carotid occlusion or severe stenosis is well documented. This study was undertaken in order to try and exploit the external carotid artery as a collateral pathway to avoid cerebral ischaemia during carotid surgery. The main problem is to ascertain when the external carotid artery is relevant to cerebral perfusion, and to assess if the insertion of a shunt from the common to the external carotid artery is a useful way of ensuring adequate cerebral perfusion in patients with cerebral ischaemia during carotid clamping. In order to do this, it was necessary to assay the haemodynamic role of the external carotid artery by means of a technique which monitors cerebral function in a reliable way. We tried to evaluate this possibility by an intra-operative haemodynamic study during carotid surgery in 35 patients operated on under local anaesthesia. The insertion of a shunt between the common and external carotid artery was able to reverse brain ischaemia during clamping in four of eight patients with a neurological deficit during temporary carotid occlusion. In selected cases therefore cerebral protection with an external carotid shunt might be a valuable adjunct in the performance of carotid surgery.

Subclavian-external carotid artery bypass graft. Restoring blood flow to the brain

This article describes an unusual surgery for a type of carotid artery disease. The perioperative nurse has an important role on the vascular team when performing this procedure. For this reason, a thorough knowledge of the events and possible complications are important in the care of these patients. Careful preoperative nursing assessment and postoperative follow-up will help prevent any complications and promote a successful outcome in these patients.

Current management of the patient with internal carotid artery occlusion

Despite the recent controversy concerning surgical therapy of patients with carotid artery disease, rational therapeutic plans can be developed based on available data. The patient who is symptomatic from occlusion of one or both internal carotid arteries is at particularly high risk for development of stroke and can ill-afford indecision. All symptomatic patients, therefore, with any of the extracranial occlusive disease patterns described are potential surgical candidates. Conversely, among the asymptomatic patients with these same patterns of occlusion, only those with internal carotid occlusion and contralateral stenosis should be considered for surgical therapy. Treatment must be individualised and directed at revascularising stenotic (not occluded) internal carotid arteries, or important collateral vessels such as the external carotid artery and in fewer cases the vertebral artery. The asymptomatic patient with unilateral internal carotid artery occlusion and no contralateral lesions should be monitored closely with Duplex scanning for development of a contralateral stenosis. When a stenosis of 80% or greater is encountered, strong consideration should be given to prophylactic endarterectomy in these patients due to their high risk for stroke. Endarterectomy for a 50-60% stenosis may also be reasonable in a single patent internal carotid artery. In the absence of a significant contralateral stenosis, no treatment is necessary. Individuals with internal carotid artery occlusion and symptoms referable to a contralateral carotid stenosis should also be managed with endarterectomy of the stenotic carotid artery.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

OODG-Ulrich and OPG-Gee: a comparative study

For an adequate assessment of both the ophthalmological and the neurological consequences of carotid obstruction measurement of the blood pressure in the carotid flow area is essential. To this end there are two objective, registrating methods available at the moment: OPG-Gee and OODG-Ulrich. A comparative study was made into the basic principles, calibration curves and application methods of these systems. By both methods the systolic retinal--and ciliary--as well as the diastolic ocular blood pressure can be measured. OODG is more exact for the differentiation and measurement of the two systolic blood pressures. OPG-Gee, however, offers the unique additional possibility of a judgement on the systolic blood pressure in the carotid siphon without, however, taking into account a (difference in) pre-existing intraocular pressure. Our own investigation shows that in order to obtain a correct assessment of the carotico-brachial relation both blood pressures should be measured simultaneously. The results of the graphic analysis of the curves are compared to those by Ulrich. For the diagnosis of carotid obstructions this analysis of the shape had no advantages over the determination of the pressure values. Finally, a survey is given of possible applications of OPG and OODG in various other syndromes.

Subclavian-external carotid bypass for symptomatic severe cerebral ischemia from common and internal carotid artery occlusion

Occlusion of the common and internal carotid arteries in a patient with symptomatic severe cerebral ischemia, with or without contralateral carotid disease, portends a poor prognosis. The present study has described our experience with subclavian and external carotid artery revascularization for symptomatic severe cerebral ischemia from common and internal carotid artery occlusion. Nine patients (five men and four women) with a mean age of 62 (range 41 to 82 years) were diagnosed as having symptomatic severe cerebral ischemia. All patients had ipsilateral hemispheric symptoms, seven had amaurosis fugax, and two had associated syncope. Four patients (three men and one woman) were hypertensive, four (two men and two women) had diabetes, eight smoked, and all had a history of coronary artery disease. All of the patients had noninvasive laboratory studies and preoperative angiography, and three had postoperative angiography. Five patients were successfully revascularized to a patent external carotid artery despite nonvisualization by angiography. Six patients had unilateral and three bilateral occlusion of the common and internal carotid arteries appropriate to their symptoms. Using regional anesthesia, four patients underwent a subclavian-external carotid bypass with polytetrafluoroethylene; saphenous vein was used in five; and three had concomitant axilloaxillary bypass grafting with polytetrafluoroethylene. Neurologic improvement (that is, no subsequent deficit and no progression of symptoms) was noted in all nine patients with a follow-up of 4 to 28 months (mean 11.2 months). Two patients died from myocardial infarction 4 and 7 months after operation. Subclavian-external carotid artery bypass is a safe addition to the options for the treatment of symptomatic severe cerebral ischemia with occlusion of the common and internal carotid arteries, visualization of a superior thyroid collateral vessel on the recipient end, and nonvisualization of the external carotid artery.

Stump embolization from an occluded internal carotid artery. Case report

A patient with known internal carotid artery occlusion developed transient ischemic attacks in the distribution of the occluded vessel. Arteriography demonstrated a thrombus clearly originating from the internal carotid artery stump, which was unassociated with significantly stenotic atherosclerotic disease of the ipsilateral common or external carotid arteries. Stump angioplasty and endarterectomy led to complete and sustained cessation of further symptoms.

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.

Is external carotid endarterectomy a durable procedure?

Thirteen patients with internal carotid occlusion underwent 14 primary external carotid revascularization procedures over a 31 month period. Ten patients had obliteration of their internal carotid stump combined with patch angioplasty of the external carotid artery, and 3 had vein bypasses from the common carotid artery to the external carotid artery. Eleven patients were symptomatic with either amaurosis fugax or hemispheric transient ischemic attacks. Two patients were asymptomatic. All patients had serial carotid noninvasive tests (B-mode ultrasonography, spectral analysis, and oculoplethysmography). The mean follow-up was 22 months. Recurrent amaurosis fugax secondary to recurrent stenoses developed in two patients. These were correctly predicted by B-mode imaging and altered flow characteristics on spectral analysis. Both patients were successfully treated with reoperative procedures to prevent failure of the primary reconstruction. External carotid revascularization is a safe and durable procedure, but careful periodic follow-up is necessary to detect stenoses developing at or remote from the initial operative site. Carotid noninvasive tests appear to be helpful in detecting recurrent disease. Carotid revascularization is superior to other forms of therapy in patients who have development of neurologic symptoms ipsilateral to a chronically occluded internal carotid artery.

Internal carotid artery stump angioplasty for the treatment of cerebrovascular occlusive disease

Nineteen patients underwent a total of 21 stump angioplasty procedures for an occluded internal carotid artery. Indications for surgery included the preparation of the donor vessel for a subsequent extracranial-intracranial bypass procedure, the occurrence of emboli to the intracranial vasculature from the external carotid artery circulation, and the association with symptomatic occlusive disease of the external carotid artery accompanying occlusion of the ipsilateral internal carotid artery. The technique utilized and the results obtained in these 19 patients are presented. In select patients, the removal of an occluded internal carotid artery stump via a stump angioplasty is beneficial in preventing the catastrophic sequela of embolic cerebrovascular disease.

Internal carotid artery occlusion: clinical and therapeutic implications

Five hundred patients referred to the Cerebrovascular Clinic of the Johannesburg Hospital were examined by a battery of noninvasive tests and angiography. Thirty four occlusions of the internal carotid artery were found in 32 patients. These patients were prospectively evaluated, including clinical examination, analysis of risk factors and subsequent management. This group of patients was followed up for a mean period of 18 months, and the clinical and laboratory findings and follow up data of this group were compared to an age and sex matched group of patients with matched presenting symptoms, but with patent internal carotid arteries on angiography. Four clinical patterns emerged in the patients with occluded carotid arteries; asymptomatic (3), TIA's (17), initial fixed stroke (7), and TIA with subsequent stroke (5). Follow up of the occluded group revealed 19 patients (59%) with no further symptoms and no indication for surgical intervention. Nine patients required surgery; 4 external carotid endarterectomies (ipsilateral), 4 internal carotid endarterectomies (contralateral), and one extracranial to intracranial bypass. Two were lost to follow up and one died. After 18 months mean follow up 29 patients (91%) were well and asymptomatic. Follow up for a similar period of the non-occluded group revealed three deaths, three late strokes and three myocardial infarctions. None were lost to follow up. After 19 months mean follow up 26 patients (81%) were well with no new neurological symptoms. The prognosis of appropriately treated patients with total occlusion of the internal carotid artery does not appear to be worse than in patients with similar presenting features and patent carotid arteries.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebro-retinal ischemia after bilateral occlusion of internal carotid artery. A study with prospective follow-up

Seven patients with occlusion of internal carotid arteries (ICAs) were prospectively followed during a mean period of 14 months. Prior to demonstration of occlusions, four patients suffered a mild stroke, and three isolated transient ischemic attacks (TIAs) or amaurosis fugax. All patients remained alive and with an unchanged functional ability. During follow-up, one patient suffered amaurosis fugax and TIAs followed by a mild stroke, three suffered isolated TIAs or amaurosis fugax, two suffered reversible cerebro-retinal ischemia of more than 24 hours, and one remained symptom free. In three cases, delayed cerebro-retinal ischemia distal to one of the occluded ICAs was systematically triggered by orthostatic, cardiogenic or iatrogenic hypotension, and resolved after adequate medical treatment or restoration of a functional collateral circulation by endarterectomy of a tightly stenosed ipsilateral external carotid artery (ECA), suggesting hemodynamic phenomena. In three cases, micro-emboli originating from a stump or an ulcerated ipsilateral common carotid artery and migrating through well-developed ECA collateral channels explained delayed episodes of ipsilateral TIAs or amaurosis fugax, which disappeared in two cases after adequate anticoagulant therapy was introduced. Bilateral occlusion of ICA may be a relatively benign condition, if the patients are carefully controlled and treated.

Surgical and nonsurgical treatment of total carotid artery occlusion

The natural history of totally occluded internal and common carotid arteries was studied in 102 patients (109 arteries) with a 97 percent follow-up (mean 39.7 months.) Symptomatic occlusions occurred in 72.6 percent of the patients, the reconstructed group (46 patients) having a greater number of symptomatic vessels than the nonreconstructed group (63 patients) (p less than 0.05). Contralateral disease was encountered in 46 percent. Initial mortality was 5 percent. Twenty patients (19.6 percent) were dead at the time of follow-up. Half of these deaths were from strokes and three fourths from atherosclerotic causes. Persisting neurologic symptoms were present in 14 percent of the patients and new events occurred in 5 percent. Fifteen percent of initially asymptomatic vessels were symptomatic at last follow-up. Twenty-one percent of the symptomatic occluded vessels were symptomatic on follow-up, 16 percent being in the reconstructed group and 26 percent in the nonreconstructed group.

Occlusion of internal carotid artery. Further clinical angiographic, and therapeutic considerations

Patients with occlusion of ICA have been reviewed. Further ischemic attacks have been observed in 25-30%. The cause of the ischemia was generally embolization by way of collateral circulation through the ECA. Treatment of these patients is considered.