Contralateral Internal Carotid Occlusion Research Articles

Cerebral Neuromonitoring During Carotid Endarterectomy and Impact of Contralateral Internal Carotid Occlusion

Single-center review of patients who underwent carotid endarterectomy (CEA) between September 2008 and July 2010. The authors performed 118 consecutive eversion CEAs under local anesthesia for symptomatic (66%; n = 78) and asymptomatic (34%; n = 40) carotid stenosis. Selective shunting was performed only for patients who developed neurologic changes after carotid clamping, regardless of stump pressure (SP) and was required in 10% (12) of cases. The mean SP in shunted patients was 23 mm Hg and was < 31 mm Hg in all 12 patients. Shunting was required in 50% (4/8) of patients with contralateral occlusion, who had significantly lower mean SP. Shunting was three times more likely in patients with preop stroke (21%; 8/38) vs those without preop stroke (6%; 4/72). The results suggest that mean SP < 31 mm Hg is a reliable and safe threshold for determining the need for shunting during CEA under general anesthesia.

Cerebral Neuromonitoring during Carotid Endarterectomy and Impact of Contralateral Internal Carotid Occlusion

The aim of this study was to identify the reliability of carotid artery stump pressure (SP) in predicting the neurologic changes and correlation with contralateral internal carotid artery (ICA) occlusion in patients undergoing eversion carotid endarterectomy (CEA). The optimal method for monitoring cerebral perfusion during CEA, performed under either local or general anesthesia, is still controversial. We prospectively analyzed 118 consecutive patients undergoing eversion CEA under local anesthesia. We had 78 symptomatic (66%) and 40 asymptomatic patients (33.9%). Selective shunting was performed in patients who developed neurologic changes after carotid clamping regardless of SP. Correlation of preoperative symptom status, a degree of stenosis, status of contralateral ICA, arterial blood pressure, SP value, and the intraoperative need for shunting due to neurologic changes was evaluated for both groups: shunted and nonshunted. Selective shunting was performed in 12 patients (10%). There was no significant difference among the groups regarding the demographic characteristics. Mean carotid clamping time was 14.57 minutes. We had no perioperative mortality, stroke, or myocardial infarction. None of the patients required conversion to general anesthesia. We found a mean SP of 31 mm Hg as a reliable threshold for shunting (P < .001; sensitivity 92.3%; specificity 91.3%). Contralateral carotid occlusion was correlated with the significantly lower SP (27 ± 13 mm Hg; P = .001) and the higher need for shunt (50%). SP measurement is a reliable and simple method for monitoring the collateral cerebral perfusion and can predict the need for shunting during CEA. Patients with the contralateral ICA occlusion showed significantly lower SP, although it did not have impact on the outcome.

Contralateral carotid artery occlusion is not a contraindication to carotid endarterectomy even if shunts are not routinely used

Although controversial, carotid artery stenting (CAS) has been proposed as being safer than carotid endarterectomy (CEA) for patients with a contralateral internal carotid occlusion (CCO). Arguably, with a CCO, CAS should be even safer than CEA if a shunt is not used. Accordingly, we reviewed our experience with 2183 CEAs performed routinely without a shunt to evaluate the risk of CEA performed in a subset of 147 patients with a CCO. Between 1988 and 2011, 147 CEAs (111 men [75%], 36 women [25%]) were routinely performed without a shunt despite CCO. Of these patients, 76% were asymptomatic. CEAs were performed by seven surgeons using standard techniques (not eversion), with patients under general anesthesia and blood pressure maintained at >130 mm Hg. All patients received heparin (7500 U), and protamine reversal was routine. Median cross-clamp time was 20 minutes (range, 14-40 minutes). Three neurologic events occurred ≤ 30 days (2.0%). One transient ischemic attack (TIA) occurred immediately, and one occurred on the first postoperative day due to occlusion of the endarterectomy site. One patient sustained an immediate stroke and died of a large computed tomography-documented atheroembolic shower. Our data demonstrate the safety of CEA in the presence of a CCO, even when performed without a shunt. It is unlikely that the stroke or delayed TIA could be attributed to nonshunting or CCO. Even if so, the stroke and death rates would be lower than those previously reported for patients undergoing CEA in the presence of a CCO. This may be due to short cross-clamp times, careful technique, general anesthesia, and blood pressure support. Given these low adverse event rates, our experience refutes the assumption that patients with a CCO are at such a high risk for CEA that the only alternative is CAS.

Invited commentary

In this retrospective study, Samson and colleagues present excellent results (2% neurologic event rate, 0.7% mortality, and no clinically apparent myocardial infarctions) in 147 consecutive contralateral carotid occlusion patients, who underwent carotid endarterectomy (CEA) without shunting. They attribute their success to the use of general anesthesia with careful maintenance of systolic blood pressure above 130 mm Hg. Their results add fuel to the controversies over neurologic risk in contralateral occlusion patients and over the role of shunting. While provocative, the study is not definitive. It suffers from the weaknesses inherent in retrospective analyses. The credibility of the outcome data suffers from the absence of independent routine pre- and post-CEA neurologic assessment and of a set protocol for post-CEA brain imaging. It is almost certain that there were more perioperative strokes than they report, though these events were clinically silent or subtle. Furthermore, given the authors' use of phenylephrine-induced hypertension as a means of cerebral protection, their failure to routinely monitor postoperative cardiac enzymes represents a missed opportunity to confirm the safety of their protocol. Theoretically, at least, the routine use of vasopressors will add to the hemodynamic stress of the surgery, thereby raising the risk of perioperative cardiac morbidity. Despite these shortcomings, this report confirms four facts: (1) Well-trained surgeons, working with detail-oriented anesthesiologists and adhering to well-defined management protocols, can achieve excellent results with CEA even in putatively high-risk patients. (2) CEA patients with contralateral occlusion are not necessarily at high neurologic risk. (3) The argument that contralateral occlusion represents an indication for carotid stenting is specious. (4) Contralateral occlusion is not an absolute indication for shunt placement during CEA. The report does not establish the superiority of the authors' practices, but it does establish their management protocol as one acceptable approach to the management of CEA patients with contralateral occlusion. Those who achieve excellent results in this patient population with carotid stenting or with CEA with shunting are not likely to be converted by these data, but now have another standard against which to measure their outcomes. Controversy over the risk associated with contralateral occlusion and the role of shunting will continue. In the face of ongoing controversy, surgeons will continue to adopt and report those practices that provide optimal results for their patients. Contralateral carotid artery occlusion is not a contraindication to carotid endarterectomy even if shunts are not routinely usedJournal of Vascular SurgeryVol. 58Issue 4PreviewAlthough controversial, carotid artery stenting (CAS) has been proposed as being safer than carotid endarterectomy (CEA) for patients with a contralateral internal carotid occlusion (CCO). Arguably, with a CCO, CAS should be even safer than CEA if a shunt is not used. Accordingly, we reviewed our experience with 2183 CEAs performed routinely without a shunt to evaluate the risk of CEA performed in a subset of 147 patients with a CCO. Full-Text PDF Open Archive

Contralateral occlusion is not a clinically important reason for choosing carotid artery stenting for patients with significant carotid artery stenosis

Contralateral carotid artery occlusion by itself carries an increased risk of stroke. Carotid endarterectomy (CEA) in the presence of contralateral carotid artery occlusion has high reported rates of perioperative morbidity and mortality. Our objective was to determine if there is a clinical benefit to patients who receive carotid artery stenting (CAS) compared to CEA in the presence of contralateral carotid artery occlusion. We conducted a retrospective medical chart review over a 4.5-year institutional experience of persons with contralateral carotid artery occlusion and ipsilateral carotid artery stenosis who underwent CAS or CEA. The main outcome measures were 30-day cardiac, stroke, and mortality rate, and midterm mortality. Of a total of 713 patients treated for carotid artery stenosis during this time period, 57 had contralateral occlusion (~8%). Thirty-nine of these patients were treated with CAS, and 18 with CEA. The most common indications for CAS were prior neck surgery (18), contralateral internal carotid occlusion (nine), and prior neck radiation (seven). The average age was 70 ± 8.5 for CEA and 66.7 ± 9.3 for CAS (P = .20). Both groups were predominantly men (CEA 12 of 18; CAS 28 of 39; P = .76), with similar prevalence of symptomatic lesions (CEA 8 of 18, CAS 20 of 39; P = .77). Two patients died within 30 days in the CAS group (5%). No deaths occurred within 30 days in the CEA group (P = .50); the mortality rate for CAS and CEA combined was 3.5%. No perioperative strokes or myocardial infarction occurred in either group. Two transient ischemic attacks occurred after CAS. At mean follow-up of 29.4 ± 16 months (CEA) and 28 ± 14.4 months (CAS; range, 1.5-48.5 months), seven deaths occurred in the CAS group and one in the CEA group (17.9% vs 5.5%; P = .40). There were two reinterventions in the CAS group for in-stent restenosis and there were no reoperations in the CEA group. Although CEA and CAS can both be performed with good perioperative results and acceptable midterm mortality, the observed outcomes do not support use of contralateral carotid artery occlusion as a selection criterion for CAS over CEA in the absence of other indications.

Bilateral spontaneous internal carotid artery dissection with both early and very late recanalization: A case report

Spontaneous bilateral internal carotid artery dissection has frequently been described in the literature as a cause of stroke. In more than half of the patients with internal carotid artery dissection, recanalization occurs early after the event and is unusual later than 6 months after onset of the dissection. We describe a patient with ischemic stroke due to left internal carotid artery occlusion in the extracranial segment. The patient was treated with anticoagulants and early vessel recanalization did not occur. Ten months later, he developed contralateral internal carotid occlusion in the intracranial tract, which was followed by early complete recanalization. Anticoagulation therapy was continued and, 16 months after the initial event, the left internal carotid artery unexpectedly also reopened.

“Protected” Wallstenting of Atheromatous Stenoses at the Carotid Bifurcation

Atheromatous stenoses at the carotid bifurcation were treated by angioplasty and Wallstenting with cerebral protection obtained in most cases by temporary occlusion of the internal carotid artery. 287 carotid stenoses were treated in 233 patients. The stenosis was symptomatic in 79% of cases. All patients presented either a stenosis of >70% with significant impairment of the cerebral circulation (281 cases) or a symptomatic ulcerated plaque (six cases). A self-mounted protection system was used in 177 cases, the Percusurge Guardwire protection device in 98 cases an EPI filter in 12 cases. There was a contralateral internal carotid occlusion in 13% of cases. A combined stenting (vertebral, siphon, subclavian) was performed in 14% of cases. A Rolling membrane Wallstent was used in 84 patients, a first generation Easy Wallstent in 38 cases, a "Carotid" Easy Wallstent 35 in 55 cases and monorail 14 in 110 cases. Full opening of the stenosis was obtained in 98% of patients with correction of the arterial curve and improvement of the cerebral vascular supply. There were 0.7% cases with transient symptomatic neurological complications and 2% with permanent sequelae mainly related to avoidable inadequacy in flushing or to the insufficient radial force of the first generation Easy Wallstent. There were no per and one post-procedural cardiac complication (0.6%) in the s165 cases performed with the "Carotid" Easy Wallstent. Follow-up angiograms showed 0.7% of restenoses. Still in evolution, endovascular treatment of atheromatous stenoses at the carotid bifurcation with cerebral protection and stenting is a promising alternative technique to surgery. The association of Carotid Easy Wallstent 14 monorail and Percusurge Guardwire appears to be currently satisfactory.

EEG as a Criterion for Shunt Need in Carotid Endarterectomy

The efficacy of continuous intraoperative electroencephalographic (EEG) monitoring as a criterion for selective shunt use during carotid endarterectomy is evaluated in a group of 1661 operations in which the EEG was the sole criterion for shunt insertion. EEG monitoring is measured by the intraoperative stroke rate. Carotid stump pressure measurements were recorded as an additional observation in 1517 operations and represent a subset of the study group allowing comparison of this technique with EEG. Intraoperative stroke rate for the 1661 operations in the study group was 0.03% (five strokes). A statistically significant increase in intraoperative stroke rate was associated with the development of an abnormal EEG (1.1%), contralateral internal carotid artery occlusion (1.8%), and the combination of both abnormal EEG and contralateral internal carotid occlusion (3.3%). The EEG remained normal in 1295 operations including 75 operations with contralateral internal carotid artery occlusion. One minor intraoperative stroke (0.08%) which resolved in 1 week occurred in the absence of an EEG change with no intraoperative strokes in the 75 operations in which the contralateral internal carotid artery was occluded. Intraoperative EEG monitoring accurately (99.92%) identified patients who may safely have carotid endarterectomy without the need of a shunt.

頚動脈内膜剥離術と冠動脈バイパス術との同時手術 Ｏｆｆ ｐｕｍｐ ＣＡＢＧとの同時手術の有用性

The role of combined carotid endarterectomy (CEA) and coronary artery bypass grafting (CABG) in patients with severe carotid artery stenosis and concurrent coronary artery stenosis is still controversial. However, patients with severe carotid stenosis experience a higher rate of perioperative cerebrovascular events, compared with those without serious stenosis. Simultaneous operations have been performed in our institute since 1999, and we report the efficacy of combined CEA and CABG especially without cardiopulmonary bypass (off-pump CABG=OPCABG).Five combined oprations were performed between December 1999 and March 2001. All patients had multiple coronary lesions with more than 75% unilateral carotid stenosis. One patient had contralateral internal carotid occlusion and 1 had the tandem lesions at the distal internal carotid artery and middle cerebral artery concomitantly. Four were asymptomatic neurologically and 1 was symptomatic. Cerebral hemodynamics in all patients was examined with single photon emission CT (SPECT) and cerebral angiography, but none of them demonstrated hemodynamic compromise before operation. Three patients were treated with CEA and off-pump CABG, and 2 were CEA and CABG with cardiopulmonary bypass. CEA preceded CABG, but the saphenous veins were taken in the course of endarterectomy. After CEA, the operative field was turned over to the cardiovascular team with the cervical wound being opened. Subsequently the cardiovascular team performed CABG with off-pump or pump. Off-pump CABG brought less blood loss from the cervical wound for the minimum anticoagulant than CABG with cardiopulmonary bypass.No cardiac event occurred perioperatively, but 1 patient with transient neurological ischemic attack with tandem lesions had a transient neurological ischemic attack during hemodialysis on the day after the operation. All the patients were discharged without neurological deterioration.Preoperative screening to the supra-aortic artery is helpful for evaluating the presence of carotid or intracranial vessels in patients undergoing CABG, and cerebral blood flow studies to clarify the cerebral hemodynamics are important for patients with both carotid and coronary occlusive diseases. It is still not clear what patients are suitable for the combined operation, but all the patients with high grade carotid stenosis can undergo the combined operation with off-pump CABG with the benefits of low morbidity and patient convenience.

Treatment of Recurrent Cerebrovascular Disease Review of a 10-Year Experience

The authors determined whether carotid endarterectomy in patients with recurrent cerebrovascular disease poses a greater perioperative risk than for those individuals undergoing first-time carotid endarterectomy. A percentage of patients undergoing carotid endarterectomy for atherosclerosis experience recurrent cerebrovascular disease. Reoperation may be difficult because of postoperative scarring of the soft tissues of the neck and the carotid artery itself. Such patients were believed to be at greater risk for perioperative morbidity than those undergoing first-time carotid endarterectomy. To address this concern, the authors retrospectively reviewed their experience with 69 patients who underwent repeat carotid endarterectomies over a recent 10-year period of time. This subgroup represented 6.4% of 1072 total carotid endarterectomies performed during the same time period. The average extent of stenosis on the operated side was 81% and the time elapsed after previous endarterectomy averaged 83 months. Twelve patients (17.4%) had contralateral internal carotid occlusion, and 30 patients (43.5%) had undergone previous endarterectomies on the contralateral side. Complications within 30 days of operation included two deaths (2.9%) and one stroke (1.4%), for a combined stroke and death rate of 4.3%. Six patients developed cervical hematomas requiring drainage; one of these had rupture of a saphenous vein patch. No patient had a significant cranial nerve injury in the reoperative group, whereas 2.0% of patients undergoing first-time carotid endarterectomy had cranial nerve injuries. Overall, these results compared favorably with a combined stroke and death rate of 4.0% among 1003 patients who underwent first-time carotid endarterectomy during the same period. This review suggests that repeat carotid endarterectomy can be performed safely in individuals with severe recurrent carotid stenosis, with morbidity and mortality rates similar to those for patients undergoing first-time carotid endarterectomies. For this population, reoperative carotid endarterectomy represents a safe and important mechanism for the prevention of stroke.

The selection for shunting in patients with severe bilateral carotid lesions

Patients with severe bilateral carotid lesions (stenosis and contralateral internal carotid occlusion) are at high risk of having a stroke, and carotid endarterectomy has been proposed as the best treatment. In spite of improvements in surgical technique, this operation is still associated with significant perioperative complications (5-13%) which are frequently (up to 40%) correlated with intolerance to internal carotid artery clamping. For this reason, intraoperative cerebral monitoring able to accurately detect ischaemia during surgery would be useful. Reviewing our experience from the last 7 years in 74 patients operated on for stenosis and contralateral occlusion of the internal carotid artery, we found a 1.3% neurological morbidity and 1.3% mortality rate. Presenting symptoms included focal transient ischaemia attacks (TIAs) in 57 patients, stroke in 16 patients and two patients were asymptomatic. Half of these patients (37) were operated on under general anaesthesia with electroencephalogram (EEG) monitoring, stump pressure measurement and selective shunting. In this group, two patients (5.4%) sustained a postoperative stroke, one of which was fatal. The remaining 37 patients were operated on under local-regional anaesthesia with selective shunting on the basis of neurological deficit onset or loss of consciousness during the test clamp. There were no postoperative neurological complications in this group but one patient died of acute myocardial infarction on the 6th postoperative day. This experience suggests that it is possible to perform carotid endarterectomy in patients with severe bilateral lesions with a postoperative complication rate similar to that in patients with less complicated obstructive lesions if accurate intraoperative cerebral monitoring is used.

Carotid endarterectomy for high plaques

Seventeen instances of high plaque (plaque extending up to the level of the second cervical vertebra) were encountered out of a total of 454 carotid endarterectomies (3.7 percent). With careful dissection and knowledge of anatomy superior to hypoglossal nerve, carotid endarterectomy was accomplished without resorting to mandibular subluxation or dislocation. There was no operative mortality or perioperative strokes. One patient had perioperative myocardial infarction and another sustained temporary glossopharyngeal nerve dysfunction. High carotid plaques were more common in male patients with bilateral stenoses or contralateral internal carotid occlusion and could be suspected by findings of preoperative carotid arteriography in some instances. In the majority of cases, extension of high plaque in a tongue-shaped manner on the posterior wall of the internal carotid artery was an unexpected finding at the time of carotid endarterectomy.

Postoperative stroke and late neurologic complications after carotid endarterectomy.

From 1969 through 1973, 335 consecutive patients (mean age, 60 years) underwent 390 carotid endarterectomies using hypercarbic general anesthesia and no carotid shunting. Early neurologic complications were most common among patients with previous neurologic symptoms and among those with subtotal stenosis or occlusion of the contralateral internal carotid artery. The introduction of routine carotid shunting without hypercarbia during a subsequent series of 626 procedures from 1974 through 1978 has been associated with significantly fewer operative strokes in comparable groups of patients. Complete follow-up information during a mean interval of 8.6 years is available for 95% of 325 operative survivors. Late completed strokes have occurred in 17% of patients but have involved the cerebral hemisphere on the side of previous carotid endarterectomy in only 7%. Of 93 operative survivors who had subtotal stenosis of the contralateral internal carotid artery, 45 underwent contralateral endarterectomy as an elective procedure and 48 did not. The late contralateral stroke rates for these two groups of patients were 4% and 16%, respectively, although these differences did not attain statistical significance. Forty-nine (78%) of 63 patients with contralateral internal carotid occlusion have had no late neurologic symptoms following unilateral carotid endarterectomy.