Intracerebral hemorrhage after carotid endarterectomy associated with asymptomatic perioperative cerebral ischemia detected by cerebral perfusion imaging: case report

BACKGROUND: Risk factors for intracerebral hemorrhage following carotid endarterectomy (CEA) include perioperative cerebral ischemia, postoperative cerebral hyperperfusion, and postoperative anticoagulation therapy, and at least 2 of these risk factors are typically present in the context of intracerebral hemorrhage (ICH). CASE DESCRIPTION: A 75-year-old man with severe bilateral cervical internal carotid artery stenosis and a minor stroke resulting in left motor weakness underwent a right CEA. The operation was uneventful, and the patient did not experience new neurologic deficits upon recovery from anesthesia. Brain single photon emission computed tomography (SPECT) obtained immediately after CEA showed a perfusion defect in the right parietal lobe and absence of cerebral hyperperfusion. A computed tomography (CT) scan showed no new abnormal findings. Aspirin therapy was instituted postoperatively. On the second postoperative day, the patient experienced abrupt worsening of left hemiparesis, and subsequent CT imaging demonstrated a hematoma in the right parietal lobe. Cerebral hyperperfusion was absent on repeat SPECT. CONCLUSION: Perioperative cerebral ischemia can result in intracerebral hemorrhage after CEA even in the absence of cerebral hyperperfusion and/or anticoagulation therapy. Further, cerebral perfusion imaging performed immediately after CEA is a useful modality for the identification of occult cerebral ischemia or hyperperfusion that may lead to intracerebral hemorrhage.     

Magnetic resonance imaging in patients with cerebral hyperperfusion and cognitive impairment after carotid endarterectomy

OBJECT: Cerebral hyperperfusion after carotid endarterectomy (CEA) impairs cognitive function and is often detected on cerebral blood flow (CBF) imaging. The purpose of the present study is to investigate structural brain damage seen on magnetic resonance (MR) images obtained in patients with cerebral hyperperfusion and cognitive impairment after CEA. METHODS: One hundred and fifty-eight patients with ipsilateral internal carotid artery stenosis (> or = 70%) underwent CEA. Neuropsychological testing was performed preoperatively and at the 1st postoperative month. Cerebral blood flow was measured using single-photon emission computed tomography before, immediately after, and 3 days after surgery. Magnetic resonance imaging was performed before and 1 day after surgery. In patients with post-CEA hyperperfusion (defined as a CBF increase > or = 100% compared with preoperative values) on CBF imaging, MR images were also obtained on the 3rd postoperative day, the day on which hyperperfusion syndrome developed, and 1 month after the operation. RESULTS: The incidence of postoperative cognitive impairment was significantly higher in patients with post-CEA hyperperfusion on CBF imaging (12 [75%] of 16 patients) than in those without (6 [4%] of 142 patients; p < 0.0001). Only 1 of 5 patients with cerebral hyperperfusion syndrome developed reversible brain edema in the cerebral hemisphere ipsilateral to the CEA on MR images obtained on the day hyperperfusion syndrome occurred. However, postoperative cognitive impairment developed in all 5 patients with cerebral hyperperfusion syndrome regardless of the presence or absence of new lesions on MR images. In addition, postoperative cognitive impairment developed in 5 (45%) of 11 patients with asymptomatic cerebral hyperperfusion on CBF imaging despite the absence of new lesions on any postoperative MR images. CONCLUSIONS: Although cerebral hyperperfusion syndrome after CEA sometimes results in reversible brain edema visible on MR imaging, postoperative cerebral hyperperfusion -- even when asymptomatic -- often results in impaired cognitive function without structural brain damage on MR imaging.     

Urgent endarterectomy using pretreatment with free radical scavenger, edaravone, and early clamping of the parent arteries for cervical carotid artery stenosis with crescendo transient ischemic attacks caused by mobile thrombus and hemodynamic cerebral ischemia. Case report

A 68-year-old man with left cervical internal carotid artery stenosis suffered crescendo transient ischemic attacks caused by mobile thrombus detected by carotid echography and secondary impairment of cerebral hemodynamic reserve demonstrated by positron emission tomography. Urgent carotid endarterectomy (CEA) was performed following pretreatment with edaravone and early clamping of the carotid arteries without intraluminal shunting. The postoperative course was uneventful, and postoperative magnetic resonance imaging and single-photon emission computed tomography revealed no new cerebral ischemic lesions and no findings of cerebral hyperperfusion, respectively. The risks associated with CEA are higher for patients with evolving stroke or crescendo transient ischemic attacks than that for patients with stable disease. This case demonstrates that urgent endarterectomy for cervical carotid artery stenosis with crescendo transient ischemic attacks caused by mobile thrombi and hemodynamic cerebral ischemia can be successfully performed following pretreatment with edaravone and early clamping of the carotid arteries.     

Postoperative cerebral hyperperfusion associated with impaired cognitive function in patients undergoing carotid endarterectomy

OBJECT: Cognitive impairment occurs in 20 to 30% of patients following carotid endarterectomy (CEA). The purpose of the present study was to determine whether postoperative cerebral hyperperfusion is associated with impairment of cognitive function in patients undergoing that procedure. METHODS: Cerebral blood flow (CBF) was measured using single-photon emission computerized tomography scanning before and immediately after CEA and on the 3rd postoperative day in 92 patients with ipsilateral internal carotid artery stenosis of 70% or greater. Hyperperfusion post-CEA was defined as a 100% increase or greater in CBF compared with preoperative values. Neuropsychological testing was also performed preoperatively and at the 1-, 3-, and 6-month follow-up examinations. At the 1-month postoperative neuropsychological assessment, 11 patients (12%) displayed evidence of cognitive impairment. In addition, the incidence of postoperative cognitive impairment in patients with post-CEA hype perfusion (seven [58%] of 12 patients) was significantly higher than that in patients without post-CEA hyperperfusion (four [5%] of 80 patients; p < 0.0001). A logistic regression analysis demonstrated that post-CEA hyperperfusion was the only significant independent predictor of postoperative cognitive impairment. Of the seven patients in whom post-CEA hyperperfusion and cognitive impairment were identified 1 month postoperatively, four (including three patients with hyperperfusion syndrome) remained cognitively impaired at the 3- and 6-month follow-up examinations. CONCLUSIONS: Postoperative cerebral hyperperfusion is associated with impairment of cognitive function in patients undergoing CEA. Furthermore, the development of hyperperfusion syndrome is associated with the persistence of postoperative cognitive impairment.     

Normalization of cerebral hemodynamics and metabolism after carotid stenting in patients unfit for major surgery

There is increasing evidence that stenting is a useful strategy for internal carotid artery (ICA) stenosis in patients unfit for drastic surgery. However, it should be remembered that perioperative complications including seizure or intracerebral hemorrhage due to hyperperfusion are not so rare. The authors describe a case with severe ICA stenosis, who successfully underwent stenting as a result of intensive medical care for postoperative hyperperfusion. A 77-year-old man with a recent history of angina pectoris and transient ischemic attack was referred to our hospital. Cerebral angiography showed subtotal occlusion of the left ICA. SPECT/PET studies revealed a disturbed reactivity to acetazolamide and an increase in regional oxygen extraction fraction in the left hemisphere, suggesting a marked reduction in cerebral perfusion pressure. He successfully underwent carotid stenting. Intraoperative near-infrared monitoring showed an increase in the concentration of total and oxidized hemoglobin in the left frontal area after stenting. A SPECT study just after stenting also demonstrated hyperperfusion in the left middle cerebral artery territory. His blood pressure was carefully controlled to avoid "hyperperfusion syndrome" including headache, seizure and intracerebral hemorrhage. Follow-up SPECT/PET studies showed a normalization of hemodynamic and metabolic parameters. SPECT/PET studies are quite valuable to predict and prevent hyperperfusion syndrome after carotid stenting, and result in good clinical outcome.     

The value of acetazolamide single photon emission computed tomography scans in the preoperative evaluation of asymptomatic critical carotid stenosis.

PURPOSE: Acetazolamide (ACZ)-enhanced single photon emission computed tomography (SPECT) scans can assess both cerebral perfusion and vascular reactivity. Patients with asymptomatic critical carotid artery stenosis were evaluated for cerebral vascular reactivity to determine the effect of extracranial occlusive disease and the effect of carotid endarterectomy (CEA) on intracerebral reactivity. METHODS: In 44 patients with asymptomatic critical carotid artery stenosis, cerebral perfusion and vascular reactivity were assessed before CEA with resting and ACZ-enhanced SPECT scans. All patients had a 70% or greater ipsilateral internal carotid artery stenosis. Preoperative ACZ-enhanced SPECT scans were obtained, usually 5 days before CEA. Postoperative ACZ-enhanced SPECT scans were obtained in 30 patients. RESULTS: Preoperative SPECT scans were asymmetric, revealing focal (n = 19) or global (n = 15) decreased reactivity in 34 patients (77%). Ten patients had symmetric or normal reactivity. After CEA, 23 patients demonstrated an improvement in reactivity ipsilateral to the side of surgery. The remaining seven patients failed to improve after surgery. CONCLUSION: Although all patients had a high-grade internal carotid stenosis, nearly a quarter of the patients had excellent intracerebral collateral flow. Only 71% of patients demonstrated improved intracerebral vasoreactivity after CEA. The lack of improvement in the other patients may have resulted from intracerebral pathology or lack of improvement in the extracranial carotid hemodynamics.     

Effects of the free radical scavenger, edaravone, on the development of postoperative cognitive impairment in patients undergoing carotid endarterectomy

BACKGROUND: Some patients undergoing carotid endarterectomy (CEA) experience postoperative cognitive impairment. The purpose of the present case cohort study with historical control was to determine whether pretreatment with a novel free radical scavenger, edaravone, could prevent development of cognitive impairment after CEA. METHODS: Fifty-five patients with ipsilateral internal carotid artery (ICA) stenosis (> or =70%) underwent CEA with administration of edaravone before ICA clamping. Neuropsychological testing was performed preoperatively and at the first postoperative month. Cerebral blood flow was also measured using single-photon emission computed tomography before and immediately after CEA and on the third postoperative day. RESULTS: Postoperative cognitive impairment was observed in only 1 (2%) patient, who exhibited postoperative cerebral hyperperfusion (cerebral blood flow increase > or =100% compared with preoperative values). Incidence of postoperative cognitive impairment in the control group (92 CEA patients without administration of edaravone) was significantly higher (12%) (P = .0298, control vs treatment group). Logistic regression analysis demonstrated that postoperative cerebral hyperperfusion and absence of pretreatment with edaravone were significant independent predictors of postoperative cognitive impairment. CONCLUSION: Pretreatment with edaravone can prevent development of cognitive impairment after CEA.     

Hyperperfusion phenomenon after percutaneous transluminal angioplasty for atherosclerotic stenosis of the intracranial vertebral artery. Case report

The authors report on a patient who underwent percutaneous transluminal angioplasty (PTA) for stenosis of the intracranial vertebral artery (VA). This 67-year-old man's dizziness while walking was caused by infarction of the left cerebellar peduncle. On angiograms, his left VA manifested 90% stenosis at the intracranial portion and his right VA ended at the posterior inferior cerebellar artery. Because single-photon emission computerized tomography (SPECT) showed low perfusion and poor perfusion reserve in the posterior circulation, the authors performed PTA of the left VA, which was only 35% dilated due to stenosis. Although the patient's postoperative course was uneventful, postoperative hemodynamic studies (SPECT and transcranial Doppler [TCD] ultrasonography) revealed the hyperperfusion phenomenon. A 100% increase of regional cerebral blood flow in the posterior circulation was demonstrated on SPECT studies and TCD ultrasonography revealed a doubling of blood flow velocity in the VA compared with preoperative values. Careful control of the patient's blood pressure resulted in resolution of the hyperperfusion phenomenon within I week post-PTA. Although hyperperfusion syndrome following carotid endarterectomy is not rare, it is seldom seen after reconstruction of the posterior circulation, and the possibility of its occurrence must be kept in mind when the posterior circulation is reconstructed.     

Prediction and monitoring of cerebral hyperperfusion after carotid endarterectomy by using single-photon emission computerized tomography scanning

OBJECT: The purpose of this study was to determine whether the preoperative measurement of acetazolamide-induced changes in cerebral blood flow (CBF), which is performed using single-photon emission computerized tomography (SPECT) scanning, can be used to identify patients at risk for hyperperfusion following carotid endarterectomy (CEA). In addition, the authors investigated whether monitoring of CBF with SPECT scanning after CEA can be used to identify patients at risk for hyperperfusion syndrome. METHODS: Cerebral blood flow and cerebrovascular reactivity (CVR) to acetazolamide were measured before CEA in 51 patients with ipsilateral internal carotid artery stenosis (> or = 70% stenosis). Cerebral blood flow was also measured immediately after CEA and on the 3rd postoperative day. Hyperperfusion (an increase in CBF of > or = 100% compared with preoperative values) was observed immediately after CEA in eight of 12 patients with reduced preoperative CVR. Reduced preoperative CVR was the only significant independent predictor of post-CEA hyperperfusion. Forty-three patients in whom hyperperfusion was not detected immediately after CEA did not exhibit hyperperfusion on the 3rd postoperative day and did not experience hyperperfusion syndrome. In two of eight patients in whom hyperperfusion occurred immediately after CEA, CBF progressively increased and hyperperfusion syndrome developed, but intracerebral hemorrhage did not occur. In the remaining six of eight patients in whom hyperperfusion was detected immediately after CEA, the CBF progressively decreased and the hyperperfusion resolved by the 3rd postoperative day. CONCLUSIONS: Preoperative measurement of acetazolamide-induced changes in CBF, which is performed using SPECT scanning, can be used to identify patients at risk for hyperperfusion after CEA. In addition, post-CEA monitoring of CBF performed using SPECT scanning results in the timely and reliable identification of patients at risk for hyperperfusion syndrome.     

Unilateral carotid stenosis and impaired cerebral hemispheric vascular reserve

Single photon emission computed tomography (SPECT) scanning with 99TcHMPAO (Ceretec) was used to demonstrate regional cerebral blood flow (rCBF) in sixteen patients with hemodynamically significant unilateral carotid stenosis. All patients were demonstrated by cerebral computed tomography to be without cerebral infarction. When dysautoregulation was induced by intravenous acetazolamide, eight patients demonstrated a perfusion defect ipsilateral to carotid stenosis. Repeat SPECT scanning with dysautoregulation following carotid endarterectomy showed improved or normal cerebral perfusion in seven of these patients. The results suggest that a hemodynamic mechanism for cerebral ischemic events, including transient ischemic attacks (TIA) may be more common than previously suspected. Carotid disobliteration usually improves ipsilateral cerebrovascular reserve in patients with a preoperative perfusion defect.     

Stepwise revascularization for prevention of postoperative hyperperfusion

Abrupt normalization of cerebral blood flow (CBF) after surgical procedures to improve excessive cerebral hypoperfusion can cause irreversible brain parenchymal damage. Such hyperperfusion, which is caused by inflow at normal blood pressure into maximally dilated fine vessels, is an important complication following carotid endarterectomy (CEA). Strict control of blood pressure in the perioperative period can prevent this complication except in a few patients, who have severe cerebral hypoperfusion and poor cerebrovascular reserve due to extremely severe stenosis of the ipsilateral or the bilateral carotid arteries, for which CEA is indicated. The requirement for improved CBF and the risk of postoperative hyperperfusion conflict in the pathogenesis of these patients. We tried to prevent abrupt improvement in perfusion by attempting gradual restoration of CBF. Superficial temporal artery-middle cerebral artery anastomosis was first performed to improve the poor cerebrovascular reserve by allowing insufficient blood flow. A few weeks later, CEA was performed to completely restore CBF. This surgical approach obtained good results without postoperative problems in four patients. The indications of this surgical management and efficacy of stepwise restoration of CBF to prevent postoperative hyperperfusion depend on careful preoperative evaluation of perfusion studies.     

A case of emergency carotid endarterectomy for severe stenosis of the cervical internal carotid artery presenting with progressing stroke: importance of managing blood pressure postoperatively

We report a case treated successfully by emergency carotid endarterectomy (CEA) for progressing stroke resulting from pseudo-occlusion of the internal carotid artery (ICA). A 67-year-old male was admitted to our hospital with dysarthria. Neurological examination on admission revealed mild left-sided motor weakness and dysarthria. Computed tomography (CT) showed cerebral infarction in the territory of the perforating artery of right middle cerebral artery (MCA). Magnetic resonance (MR) imaging indicated similar findings and cervical MR angiography revealed occlusion of right cervical ICA. Cerebral conventional angiography and CT angiography revealed pseudo-occlusion of the right ICA. ECD-single photon emission tomography (SPECT) indicated low perfusion in the territory of the right ICA. Conservative therapy was performed using free radical scavengers and antiplatelet drugs, but neurological signs deteriorated. Revascularization using CEA was therefore performed. After surgery, the patient was restless with neurological abnormalities, and trans-cranial Doppler (TCD), INVOS-3100 and MRA revealed hyperperfusion. Strict control of blood pressure under propofol anesthesia allowed effective management of hyperperfusion syndrome. After a 1-month follow-up period, the patient was discharged with only mild left hemiparesis.     

Neurological deterioration due to cerebral hyperperfusion following carotid endarterectomy. Case report]

Recently attention has been drawn to postoperative cerebral hyperperfusion after carotid endarterectomy (CEA) associated with a preoperative state of impaired cerebral hemodynamics. Rarely postoperative neurological deficits are caused by cerebral edema due to hyperperfusion. The patient was a 65-year-old male with dysarthria and right hemiparesis. Because of the presence of severe stenosis of the left carotid artery, CEA was performed. On the 6th postoperative day, he developed severe right hemiparesis and aphasia due to cerebral edema in the subcortical region of the left cerebral hemisphere. Left carotid angiography showed normal circulation without evidence of the carotid stenosis. Later the cerebral edema and the neurological deficits gradually disappeared.     

Evaluation of carotid distal pressure for prevention of hyperperfusion after carotid endarterectomy

BACKGROUND: Sometimes preoperative cerebral misery perfusion induces an occurrence of hyperperfusion after carotid endarterectomy (CEA). We intraoperatively measured carotid proximal and distal pressures and evaluated their role in predicting hyperperfusion. METHODS: Twenty-one sites with an indication of CEA were preoperatively assessed based on the bilateral perfusional state of the cerebral blood flow (CBF) and delta CBF by single photon emission computed tomography (SPECT). Postoperative SPECT was performed immediately and on the fifth day after surgery. The distal and proximal pressures were intraoperatively measured through an internal shunt tube, and the evaluated relationship against hyperperfusion was shown on postoperative SPECT. RESULTS: Despite strict control of blood pressure, 7 patients postoperatively showed hyperperfusion on SPECT and 2 of them had transient neurological symptoms. The distal pressure was significantly different between the postoperative hyperperfusion group and the normal one; however, proximal pressure and the difference between proximal and distal pressures were not significantly different. In the hyperperfusion group, delta pressure was apparently higher, and delta CBF and distal pressure were significantly lower than those of the normal group. CONCLUSION: Intraoperative measurement of distal pressure as well as preoperative estimation of the cerebrovascular perfusion and the reserve is of importance in predicting postoperative hyperperfusion.     

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.     

Association of carotid artery atheromatous plaque types with cerebral perfusion

Background: In an attempt to define the association of internal carotid artery atheromatous plaque morphology with potential cerebral ischaemia, we have investigated the relationship of different carotid plaque types with defects in cerebral perfusion. Methods: In 130 patients requiring surgical correction of internal carotid artery stenoses greater than 70%, defects in cerebral perfusion due to both haemodynamic insufficiency and intracerebral vessel occlusion were identified using single photon emission computed tomography scans (SPECT). Carotid artery plaques in these patients were classified as homogeneous or heterogeneous based on preoperative Doppler Duplex Scanning and on the macroscopic characteristics of the plaques recorded by the surgeon during carotid endarterectomy, with sub‐classification into potentially embolus‐generating and non‐ embolus‐generating plaques. In individual patients, plaque types were then correlated with the perfusion defects found in the SPECT scans. Results: Of 130 patients, 112 (86%) had cerebral perfusion defects. In 56 asymptomatic patients in the study, 48 (85.7%) had perfusion defects as did 64 (86.5%) of 74 symptomatic patients. Cerebral infarcts were seen in 41 (31.5%). Occlusive infarcts (66%) were twice as frequent as haemodynamic insufficiency infarcts (34%). Eighteen patients with small cerebral infarcts on SPECT scanning gave no medical history of cerebral symptoms. Statistical analysis of the results revealed that there was no statistically identifiable association between carotid plaque type and the generation of cerebral symptoms or infarction. Conclusion: This study found that internal carotid plaque morphology has no statistically significant association with perfusion defects, symptoms or cerebral infarction in patients with significant internal carotid artery stenosis. Also, it is suggested that haemodynamic cerebral infarction may be more common that previously believed (34% of infarcts identified in the study). Further, it is suggested that plaque morphology alone is not an indication for carotid endarterectomy.     

颈动脉狭窄患者围手术期脑部并发症的诊治

目的 探讨颈动脉狭窄患者围手术期脑部并发症的原因及其防治措施.方法 回顾性分析2004年5月至2009年6月间接受外科治疗的133例颈动脉狭窄患者围手术期脑部并发症的原因及其处理方式.结果 本组133例颈动脉狭窄患者,其中男97例,女36例;年龄62～78岁,平均(67±8)岁.其中94例接受颈动脉内膜剥脱术(carotid endarterectomy,CEA),39例接受颈动脉支架植入术(carotid artery stenting,CAS);围手术期16例出现脑部并发症,其中3例发病次数在2次以上;术前5例出现短暂性脑缺血发作(transient ischemic attacks,TIA)及一过性脑供血不足等并发症;CEA术中5例、CAS术中4例出现TIA发作和脑过度灌注综合征(cerebral hyperperfusion syndrome,CHPS)等并发症;术后8例患者出现TIA发作、脑过度灌注综合征、脑梗死及脑出血等并发症.结论 有效控制围手术期脑部并发症的发生是外科治疗颈动脉狭窄成败的关健,脑部并发症的防治应贯穿整个围手术期.     

颈动脉内膜剥脱与支架置入术患者围手术期脑灌注对比分析

目的:通过全脑CT灌注成像(WBCTP)分析并比较颈动脉内膜剥脱术(CEA)与颈动脉支架成形术(CAS)对颈动脉狭窄患者围手术期脑灌注的影响及差异。方法:参照北美症状性颈动脉内膜切除术(NASCET)标准,选择32例经全脑动脉造影确诊颈动脉狭窄的患者,其中行CEA 11例、行CAS 21例。所有患者术前、术后1周均行WBCTP检查采集脑灌注数据,分析并比较两组相对脑血流量(r CBF)、相对脑血容量(r CBV)、相对平均通过时间(r MTT)的变化及差异。结果:与术前比较,两组患者术后r CBF、r CBV、r MTT均明显改善(均P0.05),两组间以上指标变化程度均无统计学差异(均P0.05)。结论:CEA、CAS两种术式均可改善颈动脉狭窄患者脑灌注,且疗效相似。     

Perioperative and Long-term Outcomes of Carotid Endarterectomy for Japanese Asymptomatic Cervical Carotid Artery Stenosis: A Single Institution Study

As the recently developed medical treatments for asymptomatic cervical carotid artery stenosis (ACCAS) have shown excellent stroke prevention, carotid endarterectomy (CEA) should be carried out for more selected patients and with lower complication rates and better long-term outcomes. We have performed CEA for Japanese ACCAS patients with a uniform surgical technique and strict perioperative management. In this study, we retrospectively investigated the perioperative complications and long-term outcomes of our CEA series. A total of 147 CEAs were carried out in 139 Japanese ACCAS patients. All patients were routinely checked for their cardiac function and high risk coronary lesions were preferentially treated before CEA. All CEAs were performed under general anesthesia using a shunt system. The postoperative cerebral blood flow was routinely measured under continued sedation to prevent postoperative hyperperfusion. The 30-day perioperative morbidity rate was 2.04%, including a perioperative stroke rate of 0.68%. There were no perioperative deaths. With regard to the long-term outcomes of the 134 followed-up patients, 9 patients were dead and 5 patients suffered from strokes, including 2 patients with ipsilateral hemispheric ischemia. The annual rates of death, all stroke and ipsilateral ischemic stroke were 1.15%, 0.64%, and 0.25%, respectively. These results showed that the perioperative morbidity and mortality rates of our CEAs were lower than those in the previous large trials. Furthermore, the long-term outcomes of this series were favorable to those reported in the latest medical treatment trials for ACCAS patients. CEA may be useful for preventing ischemic stroke in Japanese ACCAS patients.     

Cognitive impairment associated with intraoperative and postoperative hypoperfusion without neurologic deficits in a patient undergoing carotid endarterectomy

BACKGROUND: Neuropsychological testing detects cognitive impairment in 20% to 30% of patients after carotid endarterectomy (CEA). CASE DESCRIPTION: A 51-year-old man with asymptomatic right cervical internal carotid artery (ICA) stenosis underwent a CEA. Intraoperative transcranial regional cerebral oxygen saturation monitoring revealed ischemia in the right cerebral hemisphere during ICA clamping and transient hyperemia subsequent to ICA declamping. The patient recovered without the appearance of new neurologic deficits. Brain single-photon emission computed tomography performed immediately after CEA showed a decrease in cerebral blood flow in the right cerebral hemisphere. Diffusion-weighted magnetic resonance imaging showed no new abnormal findings. Positron emission tomography performed 2 months after surgery revealed decreased cerebral metabolic rate of oxygen in the right cerebral hemisphere, and neuropsychological testing demonstrated a decline in performance IQ relative to preoperative levels. CONCLUSIONS: Intraoperative ischemia and postischemic delayed hypoperfusion in CEA can impair cognition even in the absence of development of postoperative neurologic deficit.