Intracerebral hemorrhage after carotid endarterectomy associated with ipsilateral fibrinoid necrosis: a consequence of the hyperperfusion syndrome?

Cerebral hyperperfusion syndrome resulting in subarachnoid hemorrhage after carotid artery stenting

A 64-year-old, right-handed man underwent endovascular treatment for internal carotid artery stenosis after experiencing a left-hemispheric transient ischemic attack. ¹⁵O-gas and H ₂¹⁵ O positron emission tomography revealed slightly reduced cerebral blood flow (CBF), elevated cerebral blood volume, and severely reduced cerebral vasoreactivity in the ipsilateral hemisphere as determined by an acetazolamide challenge test. The patient underwent left carotid artery stenting (CAS) via a prefemoral approach under local anesthesia without any complications. Follow-up examinations performed 20 h postoperatively showed subarachnoid hemorrhage (SAH) and cerebral hyperperfusion syndrome (CHS) in the left frontal lobe. Although it is a relatively rare phenomenon, SAH resulting from CHS was determined to be specifically caused by CAS. In this case, the causes of SAH may have been related to multiple factors including increased regional CBF, loss of cerebrovascular autoregulation, contrast agent-mediated disruption of major cerebral vessels, and strong antiplatelet therapy.

Leptomeningeal collateral vessels are a major risk factor for intracranial hemorrhage after carotid stenting in patients with carotid atherosclerotic plaque

AIM

To evaluate the relationship between leptomeningeal collaterals and intracranial hemorrhage (ICH) after carotid artery stenting (CAS).

METHODS

A retrospective study was undertaken of 228 patients (median age 75 years (range 44-90); 187 men and 41 women) who underwent CAS due to unilateral carotid atherosclerotic plaque from January 2009 to December 2013. Cerebral angiographic findings were classified into three patterns: type I, normal visualization of the anterior and middle cerebral arteries without leptomeningeal collaterals; type II, visualization of the middle cerebral artery only without leptomeningeal collaterals; and type III, visualization of leptomeningeal collateral flow.

RESULTS

For all cerebral angiographic findings, 146 (64.0%) were type I, 61 (26.8%) were type II, and 21 (9.2%) were type III. Four patients (1.8%) died with fatal ICH after CAS and had type III angiographic findings (19%). The prevalence of ICH in patients with leptomeningeal collateral vessels was significantly higher than in patients without leptomeningeal collateral vessels (19% vs 0%, p<0.0001). The percentage of carotid stenosis in patients with ICH based on North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria was significantly higher than in patients without ICH (89.8±3.6% vs 72.8±12.8%, p=0.014).

CONCLUSIONS

Leptomeningeal collateral vessels are a major risk factor for ICH after CAS in patients with carotid atherosclerotic plaque.

Intraprocedural prediction of hemorrhagic cerebral hyperperfusion syndrome after carotid artery stenting

Hyperperfusion syndrome (HPS) is a rare but severe complication after carotid artery stenting (CAS). Reliable methods for predicting HPS remain to be developed. We aimed to establish a predictive value of hemorrhagic HPS after CAS. Our retrospective study included 136 consecutive patients who had undergone CAS. We determined the cerebral circulation time (CCT) by measuring the interval between the point of maximal opacification of the terminal portion of the internal carotid artery and the cortical vein. We calculated intraprocedural CCT changes (ΔCCT) by subtracting postprocedural CCT values from preprocedural CCT values. The mean ΔCCT was 0.9 ± 0.9 seconds; 3 patients (2.2%) with prolonged ΔCCT (2.7, 5.4, and 5.8 seconds) developed HPS. The cutoff time of 2.7 seconds predicted hemorrhagic HPS retrospectively with 100% sensitivity and 99% specificity. Our findings suggest that post-CAS HPS can be predicted by using the ΔCCT value obtained by intraprocedural digital subtraction angiography. Patients with a ΔCCT >2.7 seconds require careful intensive hemodynamic and neurologic monitoring after CAS.

Hyperperfusion syndrome after carotid revascularization

Cerebral hyperperfusion syndrome is a rare, serious complication of carotid revascularization either after carotid endarterectomy or carotid stent placement. Impaired cerebral autoregulation and post-revascularization changes in cerebral hemodynamics are the main mechanisms involved in the development of the syndrome. Hyperperfusion syndrome may be fatal once an intracranial hemorrhage occurs. This article reviews the literature, intending to make a synthesis of all new data concerning the clinical manifestations of hyperperfusion syndrome, the pathophysiologic pathways involved in its development, the prediction, and the appropriate management. Also, a review of the most recent series of hyperperfusion syndrome following carotid revascularization, both with classic open endarterectomy and carotid artery stenting has been performed.

Intracranial hemorrhage associated with cerebral hyperperfusion syndrome following carotid endarterectomy and carotid artery stenting: retrospective review of 4494 patients

Object

Intracranial hemorrhage associated with cerebral hyperperfusion syndrome (CHS) following carotid endarterectomy (CEA) or carotid artery stenting (CAS) is a rare but potentially devastating complication. In the present study the authors evaluated 4494 patients with carotid artery stenosis who had undergone CEA or CAS to clarify the clinicopathological features and outcomes of those with CHS and associated intracranial hemorrhage.

Methods

Patients with postoperative CHS were retrospectively selected, and clinicopathological features and outcomes were studied.

Results

Sixty-one patients with CHS (1.4%) were identified, and intracranial hemorrhage developed in 27 of them (0.6%). The onset of CHS peaked on the 6th postoperative day in those who had undergone CEA and within 12 hours in those who had undergone CAS. Results of logistic regression analysis demonstrated that poor postoperative control of blood pressure was significantly associated with the development of intracranial hemorrhage in patients with CHS after CEA (p = 0.0164). Note, however, that none of the tested variables were significantly associated with the development of intracranial hemorrhage in patients with CHS after CAS. Mortality (p = 0.0010) and morbidity (p = 0.0172) rates were significantly higher in patients with intracranial hemorrhage than in those without.

Conclusions

Cerebral hyperperfusion syndrome after CEA and CAS occurs with delayed classic and acute presentations, respectively. Although strict control of postoperative blood pressure prevents intracranial hemorrhage in patients with CHS after CEA, there appears to be no relationship between blood pressure control and intracranial hemorrhage in those with CHS after CAS. Finally, the prognosis of CHS in patients with associated intracerebral hemorrhage is poor.

Cerebral hyperperfusion syndrome

Cerebral hyperperfusion syndrome (CHS) after carotid endarterectomy is characterised by ipsilateral headache, hypertension, seizures, and focal neurological deficits. If not treated properly it can result in severe brain oedema, intracerebral or subarachnoid haemorrhage, and death. Knowledge of CHS among physicians is limited. Most studies report incidences of CHS of 0-3% after carotid endarterectomy. CHS is most common in patients with increases of more than 100% in perfusion compared with baseline after carotid endarterectomy and is rare in patients with increases in perfusion less than 100% compared with baseline. The most important risk factors in CHS are diminished cerebrovascular reserve, postoperative hypertension, and hyperperfusion lasting more than several hours after carotid endarterectomy. Impaired autoregulation as a result of endothelial dysfunction mediated by generation of free oxygen radicals is implicated in the pathogenesis of CHS. Treatment strategies are directed towards regulation of blood pressure and limitation of rises in cerebral perfusion. Complete recovery happens in mild cases, but disability and death can occur in more severe cases. More information about CHS and early institution of adequate treatment are of paramount importance in order to prevent these potentially severe complications.

Hyperperfusion Syndrome after Carotid Endarterectomy

The hyperperfusion syndrome is a rare delayed postoperative complication of carotid endarterectomy (CEA) characterized by headache and seizure, with or without intracranial edema or hemorrhage. Between January 1996 and December 2003, 1,602 CEAs were performed. Six patients (0.4%) developed symptoms of hyperperfusion within 2 weeks of surgery. All patients had critical stenoses, five > or =90% and one 80-90%, with poor backbleeding from the distal internal carotid artery noted at operation in all cases. Five patients were asymptomatic prior to operation; one had a hemispheric transient ischemic attack. Three patients had severe contralateral internal carotid disease (two occlusions and one severe stenosis). Two patients developed severe, self-limiting headache that prolonged hospitalization. Three patients had ipsilateral intracranial bleeding, two occurring after an uneventful postoperative course. After initial discharge from the hospital, severe intracranial hemorrhage caused death in two patients. One patient experienced focal seizures 1 week after discharge. Hypertension did not appear to be related to the symptoms in any case. During the study period, the hyperperfusion syndrome caused three of five perioperative strokes (60%) and two of seven deaths (29%) in the entire endarterectomy population. Although rare, the hyperperfusion syndrome accounts for a significant percentage of the neurological morbidity and mortality following CEA.

The Incidence of Ischemic Stroke versus Intracerebral Hemorrhage after Carotid Endarterectomy: A Review of 2452 Cases

Carotid endarterectomy is a frequently performed vascular procedure. The most common major perioperative neurologic complication is ischemic stroke. Intracerebral hemorrhage has been traditionally viewed as less common. It has been recently proposed that as technical advances are made, the rate of ischemic stroke and other complications has decreased, causing hemorrhagic stroke to attain increasing importance as a perioperative complication. A review of 2452 consecutive endarterectomies performed by a single surgeon from 1983 to 2000 was performed and rates of ischemic and hemorrhagic strokes were analyzed. There were five hemorrhagic strokes for a rate 0.20% (13.5% of postoperative neurologic complications) and 32 with ischemic strokes for a rate of 1.31% (86.5% of postoperative neurologic complications). From these data we conclude that hemorrhagic stroke remains uncommon and ischemic stroke continues to be the most frequent cause of postoperative neurologic complication after carotid endarterectomy.

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 hyperperfusion (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.

Pretreatment with the Free Radical Scavenger Edaravone Prevents Cerebral Hyperperfusion after Carotid Endarterectomy

OBJECTIVE:

Cerebral hyperperfusion syndrome after carotid endarterectomy (CEA) is a rare but potentially devastating complication. The purpose of the present study, which was not a randomized controlled trial but a case cohort study with historical control, was to determine whether pretreatment with a novel free radical scavenger, edaravone, could prevent occurrence of cerebral hyperperfusion after CEA.

METHODS:

Fifty patients with ipsilateral internal carotid artery stenosis (≥70%) underwent CEA with administration of edaravone before internal carotid artery clamping. Preoperative cerebral blood flow and cerebrovascular reactivity (CVR) to acetazolamide were assessed with single-photon emission computed tomography (SPECT). Cerebral blood flow also was measured immediately after CEA and on the 3rd postoperative day.

RESULTS:

Cerebral hyperperfusion (cerebral blood flow increase ≥100% compared with preoperative values) was revealed by SPECT performed immediately after CEA in only one patient (2%), who also exhibited reduced preoperative CVR. The incidence of post-CEA hyperperfusion as revealed by SPECT in the control group (51 CEA patients without administration of edaravone) was significantly higher (16%) (P= 0.0310, control versus treatment group). In addition, in a subgroup of patients with reduced preoperative CVR, the incidence of post-CEA hyperperfusion as revealed by SPECT in the edaravone group (7%) was significantly lower than that in the control group (67%) (P= 0.0029). Logistic regression analysis demonstrated that reduced preoperative CVR and absence of pretreatment with edaravone were significant independent predictors of post-CEA hyperperfusion as revealed by SPECT.

CONCLUSION:

Pretreatment with edaravone can prevent occurrence of cerebral hyperperfusion after CEA.

Intracerebral Haemorrhage Following Carotid Endarterectomy

OBJECTIVES

To determine risk factors for the development of hyperperfusion and intra-cerebral haemorrhage following carotid endarterectomy and formulate potential protocols for prevention.

METHODS

MEDLINE database search of the English language literature (1966-2002) was performed using the words 'cerebral haemorrhage', 'intracranial haemorrhage' and 'carotid endarterectomy'. Other articles were cross-referenced by hand.

RESULTS

There are no data from randomised trials confirming the significance of any single risk factor. The evidence suggests that the following may have a role: pre-operative hypertension, recent ipsilateral non-haemorrhagic stroke, previous ischaemic cerebral infarction, surgery for a > 90% ipsilateral internal carotid artery (ICA) stenosis, impaired cerebrovascular reserve, intra-operative haemodynamic or embolic ischaemia, post-operative hypertension, an ipsilateral increase of > or =175% in peak middle cerebral artery velocity (MCAV) and/or a > or =100% increase in pulsatility index.

CONCLUSIONS

A critical ICA stenosis with impaired cerebrovascular reserve resulting in maximal intracerebral vasodilatation and post-operative hyperperfusion (impaired autoregulation) appear to be central to the development of ICH. Appropriate pre-operative screening and post-operative monitoring in high risk patients might identify those who would benefit from manipulation of the haemodynamic events that appear to promote ICH.

Intracranial hemorrhage and hyperperfusion syndrome following carotid artery stenting: risk factors, prevention, and treatment

OBJECTIVES

The study defined the incidence of cerebral hyperperfusion syndrome and intracranial hemorrhage (ICH) and the risk factors for their development following carotid artery stenting (CAS).

BACKGROUND

Hyperperfusion syndrome and ICH can complicate carotid revascularization, be it endarterectomy or CAS. Although extensive effort has been devoted to reducing the incidence of ischemic stroke complicating CAS, little is known about the incidence, etiology, and prevention strategies for hyperperfusion and ICH following CAS.

METHODS

We retrospectively reviewed the prospective database of 450 consecutive patients who were treated with CAS in our department to identify patients who developed hyperperfusion syndrome and/or ICH.

RESULTS

The mean age of the patients was 72.7 +/- 10.9 years, and the mean diameter narrowing was 84 +/- 12.8%. Five (1.1% [95% confidence interval 0.4% to 2.6%]) patients developed hyperperfusion. Three (0.67%) of the five developed ICH. Two of these patients died (0.44%). Symptoms developed within a median of 10 h (range, 6 h to 4 days) following stenting. All five patients had correction of a severe internal carotid stenosis (mean 95.6 +/- 3.7%) with a concurrent contralateral stenosis >80% or contralateral occlusion and peri-procedural hypertension. These same risk factors are involved in cerebral hyperperfusion following carotid endarterectomy. The use of platelet glycoprotein IIb/IIIa receptor blockers did not appear to increase the risk ICH.

CONCLUSIONS

The hyperperfusion syndrome occurs infrequently following CAS, and ICH occurs in 0.67% of patients. Patients with severe bilateral carotid stenoses may be predisposed to ICH, particularly if there is concurrent arterial hypertension. Patients with these factors may require more intensive hemodynamic monitoring after CAS, including prolongation of hospitalization in some cases.

Delayed Cerebral Hyperperfusion Syndrome Caused by Prolonged Impairment of Cerebrovascular Autoregulation after Carotid Endarterectomy: Case Report

OBJECTIVE AND IMPORTANCE

Cerebral hyperperfusion syndrome is a rare but potentially devastating complication that typically occurs within several days after carotid endarterectomy.

CLINICAL PRESENTATION

A 66-year-old man experienced asymptomatic cerebral hyperperfusion as demonstrated by single-photon emission computed tomography (SPECT) during a 2-week period after undergoing right carotid endarterectomy. This phenomenon occurred despite intensive pharmacological control of blood pressure. On the 28th postoperative day, repeat SPECT demonstrated resolution of hyperperfusion, and intensive blood pressure control was discontinued.

INTERVENTION

Twelve hours later, the patient experienced left motor seizures with secondary generation. SPECT performed 36 hours after the onset of seizures demonstrated the reappearance of hyperperfusion. Intensive blood pressure control was reinstituted and maintained until the 36th postoperative day. On the next day, SPECT demonstrated resolution of hyperperfusion.

CONCLUSION

The present case suggests that cerebral hyperperfusion syndrome may occur at later time points (e.g., 1 mo) after carotid endarterectomy. This delayed hyperperfusion syndrome may be related to prolonged impairment of cerebrovascular autoregulation.

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.

Risk, types, and severity of intracranial hemorrhage in patients with symptomatic carotid artery stenosis

BACKGROUND AND PURPOSE

We sought to report the occurrence and risk factors of intracranial hemorrhage during long-term follow-up of patients with internal carotid artery stenosis, with and without carotid endarterectomy.

METHODS

From the prospective data of the North American Symptomatic Carotid Endarterectomy Trial, 3 types of intracranial hemorrhage were recognized: petechiae within infarction (PTI), intracerebral hematoma (ICH), and subarachnoid hemorrhage (SAH). The 30-day and 5-year risks of intracranial hemorrhage (PTI or ICH) were estimated from Kaplan-Meier event-free survival curves. Cox proportional-hazards regression modeling was used to identify risk factors.

RESULTS

Of 1039 strokes that occurred in 749 of 2885 patients during an average follow-up of 5 years, there were 24 PTIs, 14 ICHs, and 1 SAH. The 5-year risk of intracranial hemorrhage was 1.7% in both medically and surgically treated patients, but the 30-day risk of 0.64% in surgically treated patients was 10 times higher than the risk of 0.07% in medically treated patients (P=0.01). Approximately 50% of all intracranial hemorrhages were either disabling or fatal, and ICHs were more likely to be fatal than PTIs. Old age, a history of hypertension, intermittent claudication and smoking, and infarct on brain images were risk factors for intracranial hemorrhage in medically treated patients, whereas diabetes mellitus was the sole risk factor in surgically treated patients.

CONCLUSIONS

Intracranial hemorrhages are uncommon in patients with internal carotid artery stenosis but are associated with high mortality and morbidity. The risk factors for intracranial hemorrhage are different between medically and surgically treated patients.

Transcranial regional cerebral oxygen saturation monitoring during carotid endarterectomy as a predictor of postoperative hyperperfusion

OBJECTIVE

Hyperperfusion syndrome is a rare but potentially devastating complication that can occur after carotid endarterectomy (CEA). The purpose of this study was to determine whether intraoperative transcranial regional cerebral oxygen saturation (rSO(2)) monitoring via near-infrared spectroscopy could be reliably used to identify patients at risk for post-CEA hyperperfusion.

METHODS

rSO(2) was intraoperatively monitored for 50 patients undergoing CEA for treatment of ipsilateral internal carotid artery stenosis (>/=70%). Cerebral blood flow (CBF) was also assessed, with single-photon emission computed tomography, before and immediately after CEA.

RESULTS

Post-CEA hyperperfusion (CBF increase of >/=100%, compared with preoperative values) was observed for six patients. A significant linear correlation was observed between the rSO(2) increases immediately after declamping of the internal carotid artery and the CBF increases immediately after CEA (r(2) = 0.247, P = 0.0002). The sensitivity and specificity of the rSO(2) increases for detection of post-CEA hyperperfusion were 100 and 86.4%, respectively, with a cutoff point of 5%. A strong linear correlation was observed between the rSO(2) increases at the end of the procedure and the CBF increases immediately after CEA (r(2) = 0.822, P < 0.0001). Both the sensitivity and the specificity of the rSO(2) increases for detection of post-CEA hyperperfusion were 100% with a cutoff point of 10%. Hyperperfusion syndrome developed for one patient with post-CEA hyperperfusion, but intracerebral hemorrhage did not occur.

CONCLUSION

Intraoperative rSO(2) monitoring can reliably identify patients at risk for hyperperfusion after CEA.

Drug-induced iatrogenic intraparenchymal hemorrhage

Intracerebral hemorrhage is bleeding into the brain parenchyma with possible extension into the ventricles and subarachnoid space. Each year, approximately 37,000 to 52,400 people suffer from intraparenchymal hemorrhage (IPH) in the United States. This rate is expected to rise dramatically in the next few decades as a result of the increasing age of the population and a change in racial demographics. IPH accounts for 8% to 13% of all stroke cases and is associated with the highest mortality rate.

Cerebral vasoreactivity and internal carotid artery flow help to identify patients at risk for hyperperfusion after carotid endarterectomy

BACKGROUND AND PURPOSE

Hyperperfusion syndrome is a rare but potentially devastating complication after carotid endarterectomy (CEA). The aim of this study was to investigate whether preoperative measurement of cerebral vasoreactivity (CVR) and intraoperative measurement of internal carotid artery (ICA) flow could identify patients at risk for hyperperfusion after CEA.

METHODS

For 26 patients with unilateral ICA stenosis >/=70%, cerebral blood flow (CBF) and CVR were investigated before and 1 month after CEA, with resting and acetazolamide-challenge single-photon emission CT. CBF on the first postoperative day was also measured. ICA flow was measured before and after reconstruction by electromagnetic flowmeter during surgery.

RESULTS

Ipsilateral CBF on the first postoperative day significantly increased relatively (56.6+/-53.2%) as well as absolutely (37.9+/-8.8 to 57.7+/-18.0 mL/100 g per minute) in the reduced CVR group (CVR <12%) but not in the normal CVR group (CVR >/=12%) (10.3+/-15.5% and 40.6+/-7.9 to 43.9+/-5.7 mL/100 g per minute, respectively). One month later, this difference almost disappeared. Two patients showed ipsilateral CBF increase of >/=100%. A significant association of intracerebral steal with hyperperfusion (CBF increase >/=100%) on the first postoperative day was also observed. ICA flow increase after reconstruction significantly correlated with CBF increase on the first postoperative day in the reduced CVR group but not in the normal CVR group. The threshold of ICA flow increase for hyperperfusion was estimated to be 330 mL/min in the reduced CVR group.

CONCLUSIONS

Single-photon emission CT with acetazolamide challenge and ICA flow measurement during surgery could identify patients at risk for hyperperfusion after CEA, in whom careful monitoring and control of blood pressure should be initiated even intraoperatively.

Transcranial Doppler monitoring during carotid endarterectomy helps to identify patients at risk of postoperative hyperperfusion

OBJECTIVES

to investigate whether transcranial Doppler (TCD) monitoring can identify patients at risk of hyperperfusion, and whether active postoperative treatment of selected patients decreases the risk of intracerebral haemorrhage (ICH).

DESIGN

a case cohort study of 688 patients undergoing carotid endarterectomy (CEA) with intraoperative TCD monitoring.

METHODS

sixty-two patients (9%) fulfilled the TCD criteria for hyperperfusion, i.e. >100% increase of peak blood flow velocity or pulsatility index of the middle cerebral artery, compared to preclamp baseline values. In these patients, blood pressure was closely monitored and controlled postoperatively.

RESULTS

postoperatively, seven of these patients (11%) exhibited clinical signs or symptoms of hyperperfusion but no cerebral haemorrhage (ICH). This is a significantly better outcome (p <0.005) compared to a 2% incidence of ICH after CEA in previous years in our hospital.

CONCLUSIONS

patients at risk of hyperperfusion syndrome after CEA can be identified intraoperatively by TCD monitoring. In these selected patients, immediate and adequate postoperative treatment of hypertension results in a decreased risk of intracerebral haemorrhage.

Intracerebral hemorrhage after carotid endarterectomy: incidence, contribution to neurologic morbidity, and predictive factors

PURPOSE

With a diminishing rate of cardiac and neurologic events after carotid endarterectomy, intracerebral hemorrhage is gaining increasing importance as a cause of perioperative morbidity and mortality. To date, information has been largely anecdotal, and there has been no comparison with a control group of patients.

METHODS

The records of all patients experiencing symptomatic intracerebral hemorrhage after carotid endarterectomy were reviewed and compared with data from 50 randomly selected patients who did not experience intracranial bleeding. Univariate analyses were performed, using the Fisher exact test for dichotomous data and the Student t test for continuous data.

RESULTS

During a 6-year period, symptomatic intracranial hemorrhage developed in 11 (0.75%) of 1471 patients undergoing carotid endarterectomy, accounting for 35% of the 31 total perioperative neurologic events. Hemorrhage occurred a median of 3 days postoperatively (range, 0 to 18 days). Signs and symptoms included hypertension in all 11 patients, headache in 7 conscious patients (64%), and bradycardia in 6 patients (55%). Massive hemorrhage with herniation and death occurred in 4 patients (36%). Moderate hemorrhage developed in 5 patients (45%); 3 of these patients had partial recovery, and 2 had complete recovery. Petechial hemorrhage occurred in the remaining 2 patients (18%), 1 with partial and 1 with complete recovery. In comparison with the control group, there were no differences in respect to sex, indication for operation, smoking or diabetic history, and antiplatelet therapy or perioperative heparin management. Patients with intracranial hemorrhage were, however, younger, more frequently hypertensive, had a higher degree of ipsilateral and contralateral carotid stenosis, and had a higher rate of contralateral carotid occlusion.

CONCLUSION

Intracranial hemorrhage occurs with notable frequency after carotid endarterectomy and accounts for a significant proportion of neurologic morbidity and mortality. Younger patients, hypertensive patients, and patients with severe cerebrovascular occlusive disease appear to be at greatest risk for the complication.