Arterial blood pressure management during carotid endarterectomy and early cognitive dysfunction

The effect of controlled vs uncontrolled hypertension on outcomes of carotid revascularization procedures

BACKGROUND

Hypertension (HTN) has been implicated as a strong predictive factor for poorer outcomes in patients undergoing various vascular procedures. However, limited research is available that examines the effect of uncontrolled HTN (uHTN) on outcomes after carotid revascularization. We aimed to determine which carotid revascularization procedure yields the best outcome in this patient population.

METHODS

We studied patients undergoing carotid endarterectomy (CEA), transfemoral carotid artery stenting (TFCAS), or transcarotid artery revascularization (TCAR) from April 2020 to June 2022 using data from the Vascular Quality Initiative. Patients were stratified into two groups: those with cHTN and those with uHTN. Patients with cHTN were those with HTN treated with medication and a blood pressure of <130/80 mm Hg. Patients with uHTN had a blood pressure of ≥130/80 mm Hg. Our primary outcomes were in-hospital stroke, death, myocardial infarction (MI), and 30-day mortality. Our secondary outcomes were postoperative hypotension or HTN, reperfusion syndrome, prolonged length of stay (LOS) (>1 day), stroke/death, and stroke/death/MI. We used logistic regression models for the multivariate analysis.

RESULTS

A total of 34,653 CEA (uHTN, 11,347 [32.7%]), 8199 TFCAS (uHTN, 2307 [28.1%]), and 17,309 TCAR (uHTN, 4990 [28.8%]) patients were included in this study. There was no significant difference in age between patients with cHTN and patients with uHTN for each carotid revascularization procedure. However, compared with patients with cHTN, patients with uHTN had significantly more comorbidities. uHTN was associated with an increased risk of combined in-hospital stroke/death/MI after CEA (adjusted odds ratio [aOR], 1.56; 95% confidence interval [CI], 1.30-1.87; P < .001), TFCAS (aOR, 1.59; 95% CI, 1.21-2.08; P < .001), and TCAR (aOR, 1.39; 95% CI, 1.12-1.73; P = .003) compared with cHTN. Additionally, uHTN was associated with a prolonged LOS after all carotid revascularization methods. For the subanalysis of patients with uHTN, TFCAS was associated with an increased risk of stroke (aOR, 1.82; 95% CI, 1.39-2.37; P < .001), in-hospital death (aOR, 3.73; 95% CI, 2.25-6.19; P < .001), reperfusion syndrome (aOR, 6.24; 95% CI, 3.57-10.93; P < .001), and extended LOS (aOR, 1.87; 95% CI, 1.51-2.32; P < .001) compared with CEA. There was no statistically significant difference between the outcomes of TCAR compared with CEA.

CONCLUSIONS

The results from this study show that patients with uHTN are at a higher risk of stroke and death postoperatively compared with patients with cHTN, highlighting the importance of treating HTN before undergoing elective carotid revascularization. Additionally, in patients with uHTN, TFCAS yields the worst outcomes, whereas CEA and TCAR proved to be safer interventions. Patients with uTHN with symptomatic carotid disease treated with CEA or TCAR have better outcomes compared with those treated with TFCAS.

Optimization of cerebral oxygenation based on regional cerebral oxygen saturation monitoring during carotid endarterectomy: a Phase III multicenter, double-blind randomized controlled trial

BACKGROUND

Whether the optimization of cerebral oxygenation based on regional cerebral oxygen saturation (rSO2) monitoring reduces the occurrence of cerebral ischemic lesions is unknown.

METHODS

This multicenter, randomized, controlled trial recruited adults admitted for scheduled carotid endarterectomy. Patients were randomized between the standard of care or optimization of cerebral oxygenation based on rSO2 monitoring using near-infrared spectroscopy. In the intervention group, in case of a decrease in rSO2 in the intervention, the following treatments were sequentially recommended: (1) increasing oxygenotherapy, (2) reducing the tidal volume, (3) legs up-raising, (4) performing a fluid challenge and (5) initiating vasopressor support. The primary endpoint was the number of new cerebral ischemic lesions detected using magnetic resonance imaging pre- and postoperatively. Secondary endpoints included new neurological deficits and mortality on day 120 after surgery.

RESULTS

Among the 879 patients who were randomized, 665 (75.7%) were men. There was no statistically significant difference between groups for the mean number of new cerebral ischemic lesions per patient up to 3 days after surgery: 0.35 (±1.05) in the standard group vs. 0.58 (±2.83), in the NIRS group; mean difference, 0.23 [95% CI, -0.06 to 0.52]; estimate, 0.22 [95% CI, -0.06 to 0.50]. New neurological deficits up to day 120 after hospital discharge were not different between the groups: 15 (3,39%) in the standard group vs. 42 (5,49%) in the NIRS group; absolute difference, 2,10 [95% CI, -0,62 to 4,82]. There was no significant difference between groups for the median [IQR] hospital length of stay: 4.0 [4.0-6.0] in the standard group vs. 5.0 [4.0-6.0] in the NIRS group; mean difference, -0.11 [95% CI, -0.65 to 0.44]. The mortality rate on day 120 was not different between the standard group (0.68%) vs. the NIRS group (0.92%); absolute difference = 0.24% [95% CI, -0.94 to 1.41].

CONCLUSIONS

Among patients undergoing carotid endarterectomy, optimization of cerebral oxygenation based on rSO2 did not reduce the occurrence of cerebral ischemic lesions postoperatively compared with controlled hypertensive therapy.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01415648.

Near-Infrared Spectroscopy-Guided, Individualized Arterial Blood Pressure Management for Carotid Endarterectomy under General Anesthesia: A Randomized, Controlled Trial

Background: Differences in blood pressure can influence the risk of brain ischemia, perioperative complications, and postoperative neurocognitive function in patients undergoing carotid endarterectomy (CEA). Methods: In this single-center trial, patients scheduled for CEA under general anesthesia were randomized into an intervention group receiving near-infrared spectroscopy (NIRS)-guided blood pressure management during carotid cross-clamping and a control group receiving standard care. The primary endpoint was postoperative neurocognitive function assessed before surgery, on postoperative days 1 and 7, and eight weeks after surgery. Perioperative complications and cerebral autoregulatory capacity were secondary endpoints. Results: Systolic blood pressure (p < 0.001) and norepinephrine doses (89 (54-122) vs. 147 (116-242) µg; p < 0.001) during carotid cross-clamping were lower in the intervention group. No group differences in postoperative neurocognitive function were observed. The rate of perioperative complications was lower in the intervention group than in the control group (3.3 vs. 26.7%, p = 0.03). The breath-holding index did not differ between groups. Conclusions: Postoperative neurocognitive function was comparable between CEA patients undergoing general anesthesia in whom arterial blood pressure during carotid cross-clamping was guided using NIRS and subjects receiving standard care. NIRS-guided, individualized arterial blood pressure management resulted in less vasopressor exposition and a lower rate of perioperative complications.

Peri-Procedural Management of Hemodynamic Instability in Patients Undergoing Carotid Revascularization

Acute perioperative changes in arterial pressure occur frequently, particularly in patients with cardiovascular disease or those receiving vasoactive medications, or in relation to certain cardiovascular surgical procedures. Hemodynamic Instability (HI) are common in patients undergoing carotid revascularization because of unique patho-physiological and surgical factors. The operation, by necessity, disrupts the afferent pathway of the baroreflex, which can lead to postendarterectomy HI. Poor arterial pressure control is associated with increased morbidity and mortality after carotid revascularization, but good control of arterial pressure is often difficult to achieve in practice. The incidence, implications, and etiology of HI associated with carotid surgery are reviewed, and some recommendations made for its management. Close monitoring and titration of therapy are probably the most important considerations rather than specific choice of agents.

[Anesthetic and Perioperative Management in Carotis Endarterectomy (CEA) - Part 2: Neurological Assessment]

The second part of "Anesthetic and Perioperative Management in Carotid Endarterectomy (CEA)" reviews the apparative/diagnostic and clinical techniques regarding neurological monitoring and perioperative complications. In particular, advantages and disadvantages concerning different methods of neurological assessment will be presented. Perioperative complications and their management will be discussed.

Management of neurophysiological monitoring changes during carotid endarterectomy exposure

BACKGROUND

Carotid endarterectomy (CEA) is a safe and effective operation in the management of carotid stenosis. Intraoperative neurophysiologic monitoring (IONM) changes during carotid clamping has been well studied, but there is scant evidence detailing IONM changes during carotid exposure.

OBJECTIVE

We analyzed our experience with IONM changes during CEA exposure to determine whether multimodal IONM changes during exposure predict outcomes and how best to manage this challenging clinical scenario.

METHODS

We reviewed all CEAs performed at our medical center between January 2015 and June 2020 and identified patients with multimodal IONM changes during exposure of the carotid artery. Our primary outcomes were perioperative stroke and functional outcomes. Functional outcomes were measured by modified Rankin scale (mRS), with good functional outcome defined at mRS scores 0-3. We also reviewed our intraoperative IONM change management strategies.

RESULTS

Five patients (4 males, 1 female) with an average age of 67 ± 12 years had intraoperative IONM changes during carotid exposure. Among these, three patients were discharged with good functional outcome, and four patients had a good functional outcome at last follow-up. Two patients had perioperative stroke, half of which resulted in significant disability. One patient was transferred to the neuroendovascular suite intraoperatively for evaluation for thromboembolism followed by angioplasty and stenting with distal protection.

CONCLUSION

Intraoperative IONM changes during carotid exposure predict outcomes in CEA. We propose that transition to the neuroendovascular suite following significant IONM changes during carotid exposure may be a useful strategy for management of this challenging clinical scenario. This approach provides the opportunity to evaluate and treat thromboembolism and still complete carotid revascularization when appropriate. This algorithm may be particularly useful in the era of dual trained vascular neurosurgeons.

Defining the awake baseline blood pressure in patients undergoing carotid endarterectomy

BACKGROUND

To minimize the incidence of intraoperative stroke following carotid endarterectomy (CEA) under general anesthesia, blood pressure (BP) is suggested to be maintained between "awake baseline" BP and 20% above. However, there is neither a widely accepted protocol nor a definition to determine this awake BP. In this study, we analyzed the BP during hospital admission in the days before CEA and propose a definition of how to determine awake BP.

METHODS

In our cohort of 1180 CEA-patients, all noninvasive BP measurements were retrospectively analyzed. BP was measured during preoperative outpatient screening (POS), the last three days before surgery at the ward and in the operating room (OR) directly before anesthesia. Primary outcome was the comparability of all these preoperative BP measurements. Secondary outcome was the comparability of preoperative BP measurements stratified for postoperative stroke within 30 days.

RESULTS

POS BP (148±22/80±12 mmHg [mean arterial pressure, MAP: 103±14 mmHg]) and the BP measured on the ward 3, 2, 1 days before surgery and on the day of surgery (146±25/77±13 [MAP: 100±15]), (142±23/76±13 [MAP: 98±15]), (145±23/76±12 [MAP: 99±14]) and (144±22/75±12 mmHg [MAP: 98±14]) were comparable (all P=NS). However, BP in the OR directly before anesthesia was higher, (163±27/88±15 mmHg [MAP: 117±18mmHg]) (P<0.01 vs. all other preoperative moments). A significant higher preinduction systolic BP and MAP was observed in patients suffering a stroke within 30 days compared to patients without (P=0.03 and 0.04 respectively).

CONCLUSIONS

Awake BP should be determined by averaging available BP values collected preoperatively on the ward and POS. BP measured in the OR directly before induction of anesthesia overestimates "awake" BP; and therefore, it should not be used.

A pilot protocol and review of triple neuroprotection with targeted hypothermia, controlled induced hypertension, and barbiturate infusion during emergency carotid endarterectomy for acute stroke after failed tPA or beyond 24-hour window of opportunity

An alternative to tissue plasminogen activator (tPA) failure has been a daunting challenge in ischemic stroke management. As tPA is time-dependent, delays can occur in definitive treatment while passively waiting to observe a clinical response to intravenous thrombolysis. Until today, uncertainty exists in the management strategy of wake-up stroke patients or those presenting beyond the therapeutic tPA window. Clinical dilemmas in these situations can prolong the transitional period of inertia, resulting in an adverse neurological outcome. We propose and review an innovative approach called triple neuro-protection (TNP), which encompasses three technical domains-targeted hypothermia, systemic induced hypertension, and barbiturates infusion, to protect the brain during carotid endarterectomy after failed tPA and/or beyond the 24-hour therapeutic mechanical thrombectomy window. This proposal assimilates discussion on the clinical evidence of the individual domains of TNP with our own clinical experience with TNP. Our first TNP was successfully employed in a 55-year-old man in 2015 while performing emergency carotid endarterectomy after he was referred to us 72 hours post tPA failure. The patient had a successful clinical outcome despite being in therapeutic inertia with 90–99% ipsilateral carotid stenosis and contralateral occlusion on presentation. In the last five years, we have safely used TNP in 25 selected cases with favourable clinical outcomes.

Decrease of Coronal Optic Nerve Sheath Diameter is Associated With Postoperative Cognitive Decline in Patients Undergoing Carotid Endarterectomy

OBJECTIVE

Patients undergoing carotid endarterectomy (CEA) have a significant possibility of developing postoperative cognitive decline (POCD). POCD after surgery could be result from cerebral hypotension induced by cross-clamping or postoperative hyperperfusion. Optic nerve sheath diameter (ONSD) exhibits an excellent correlation with invasive intracranial pressure monitoring, Here, the authors explored the risk factors of POCD in patients undergoing CEA, paying close attention to ONSD to test the hypothesis that decrease of coronal ONSD was related to the incidence of POCD.

DESIGN

Observational retrospective review.

SETTING

Single tertiary academic center.

PARTICIPANTS

One hundred sixteen patients undergoing CEA from January 1, 2019 to December 31, 2019.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

A multivariate logistic regression, scatter diagrams, and a receiver operating curve were used to evaluate the ability to predict POCD though the change in coronal ONSD. This study ultimately enrolled 84 patients and the incidence of POCD within postoperative two days was 28.6%. Decrease of coronal ONSD (odds ratio [OR], 0.438; 95% confidence interval [CI] 0.217-0.881; p = 0.021) and total intravenous anesthesia (TIVA) (OR, 25.541, 95% CI 2.100-310.614, p = 0.011) were independent risk factors for POCD. Changes in coronal ONSD had an area under the curve to distinguish POCD of 0.716 (95% CI 0.531-0.902). Using a cutoff of 0.05 cm, changes of coronal ONSD had a sensitivity of 66.7% and specificity of 66.7%.

CONCLUSIONS

Decrease of coronal ONSD, measured by ultrasonography and TIVA, were associated with POCD. Change in coronal ONSD was a moderate predictor of incidence of POCD.

Investigating Association between Intraoperative Hypotension and Postoperative Neurocognitive Disorders in Non-Cardiac Surgery: A Comprehensive Review

Postoperative delirium (POD) and postoperative cognitive decline (deficit) (POCD) are related to a higher risk of postoperative complications and long-term disability. Pathophysiology of POD and POCD is complex, elusive and multifactorial. Intraoperative hypotension (IOH) constitutes a frequent and vital health hazard in the perioperative period. Unfortunately, there are no international recommendations in terms of diagnostics and treatment of neurocognitive complications which may arise from hypotension-related hypoperfusion. Therefore, we performed a comprehensive review of the literature evaluating the association between IOH and POD/POCD in the non-cardiac setting. We have concluded that available data are quite inconsistent and there is a paucity of high-quality evidence convincing that IOH is a risk factor for POD/POCD development. Considerable heterogeneity between studies is the major limitation to set up reliable recommendations regarding intraoperative blood pressure management to protect the brain against hypotension-related hypoperfusion. Further well-designed and effectively-performed research is needed to elucidate true impact of intraoperative blood pressure variations on postoperative cognitive functioning.

Long-term cognitive decline and mortality after carotid endarterectomy

OBJECTIVES

To date no studies have evaluated long term cognitive decline after carotid endarterectomy (CEA). We evaluated whether participants who had CEA were at increased risk of cognitive decline over participants who didn't undergo CEA.

PATIENTS AND METHODS

The patients in the study were participants in the Cardiovascular Health Study (CHS), a study of 5201 men and women over the age of 65 who were recruited from four communities (Pittsburgh, Pennsylvania; Sacramento, California; Winston-Salem, North Carolina; Hagerstown, Maryland) in 1988-89. The outcomes measured were 1) Decline in 3MSE and digit symbol substitution test (DSST) scores after CEA compared to before CEA. 2) All-cause mortality in CHS cohort among participants who did and did not have CEA.

RESULTS

CEA patients had significantly greater annual decrease in the DSST scores -2.43 (SD 4.21) compared to those who did not have a CEA -1.1 (SD 2.57) (p < 0.001) but this was not seen in the 3MSE scores. CEA patients had increased the risk of decline in DSST (OR 2.41, 95 % CI 1.49, 3.88) and 3MSE (OR 2.17, 95 % CI 1.35, 3.48) scores after adjusting for age, gender, race and educational status. CEA was associated with all-cause mortality in the long term with a HR of 2.72 (95 % CI 2.22, 3.34) after adjusting for covariates. Participants with lower baseline 3MSE scores HR 1.39 (1.27, 1.51), lower DSST scores <34 HR 1.69(1.54, 1.85) were more likely deceased.

CONCLUSIONS

CEA patients are at increased risk of lower scores on 3MSE and DSST testing in the long term. Mortality in the CHS cohort was higher in participants who underwent CEA. Further, lower 3MSE and DSST scores increased the risk of mortality.

Safety of Triple Neuroprotection with Targeted Hypothermia, Controlled Induced Hypertension, and Barbiturate Infusion during Emergency Carotid Endarterectomy for Acute Stroke after Missing the 24 Hours Window Opportunity

BACKGROUND

The aim of this study is to establish the initial safety of triple neuroprotection (TNP) in an acute stroke setting in patients presenting outside the window for systemic tissue plasminogen activator (tPA).

METHODS

Over 12,000 patients were referred to our vascular services with carotid artery disease, of whom 832 had carotid intervention with a stroke rate of 0.72%. Of these, 25 patients presented (3%), between March 2015 and 2019, with acute dense stroke. These patients had either failed tPA or passed the recommended timing for acute stroke intervention. Fifteen (60%) had hemi-neglect with evidence of acute infarct on magnetic resonance imaging of the brain and a Rankin score of 4 or 5. Ninety-six percent had an 80-99% stenosis on the symptomatic side. Mean ABCD3-I score was 11.35. All patients underwent emergency carotid endarterectomy (CEA) with therapeutically induced hypothermia (32-34°C), targeted hypertension (systolic blood pressure 180-200 mm Hg), and brain suppression with barbiturate.

RESULTS

There were no cases of myocardial infarction, death, cranial nerve injury, wound hematoma, or procedural bleeding. Mean hospital stay was 8.4 (±9.5) days. All cases had resolution of neurological symptoms, except 3 who had failed previous thrombolysis. Eighty percent had a postoperative Rankin score of 0 on discharge and 88% of patients were discharged home with 3 requiring rehabilitation.

CONCLUSIONS

Positive neurological outcomes and no serious adverse events were observed using TNP during emergency CEA in patients with acute brain injury. We recommend TNP for patients who are at an increased risk of stroke perioperatively, or who have already suffered from an acute stroke beyond the recommended window of 24 hr. Certainly, the positive outcomes are not likely reproducible outside of high-volume units and patients requiring this surgery should be transferred to experienced surgeons in appropriate tertiary referral centers.

Effect of Phenylephrine and Ephedrine on Cerebral (Tissue) Oxygen Saturation During Carotid Endarterectomy (PEPPER): A Randomized Controlled Trial

Background

Short-acting vasopressor agents like phenylephrine or ephedrine can be used during carotid endarterectomy (CEA) to achieve adequate blood pressure (BP) to prevent periprocedural stroke by preserving the cerebral perfusion. Previous studies in healthy subjects showed that these vasopressors also affected the frontal lobe cerebral tissue oxygenation (rSO₂) with a decrease after administration of phenylephrine. This decrease is unwarranted in patients with jeopardized cerebral perfusion, like CEA patients. The study aimed to evaluate the impact of both phenylephrine and ephedrine on the rSO₂ during CEA.

Methods

In this double-blinded randomized controlled trial, 29 patients with symptomatic carotid artery stenosis underwent CEA under volatile general anesthesia in a tertiary referral medical center. Patients were preoperative allocated randomly (1:1) for receiving either phenylephrine (50 µg; n = 14) or ephedrine (5 mg; n = 15) in case intraoperative hypotension occurred, defined as a decreased mean arterial pressure (MAP) ≥ 20% compared to (awake) baseline. Intraoperative MAP was measured by an intra-arterial cannula placed in the radial artery. After administration, the MAP, cardiac output (CO), heart rate (HR), stroke volume, and rSO₂ both ipsilateral and contralateral were measured. The timeframe for data analysis was 120 s before, until 600 s after administration.

Results

Both phenylephrine (70 ± 9 to 101 ± 22 mmHg; p < 0.001; mean ± SD) and ephedrine (75 ± 11 mmHg to 122 ± 22 mmHg; p < 0.001) adequately restored MAP. After administration, HR did not change significantly over time, and CO increased 19% for both phenylephrine and ephedrine. rSO₂ ipsilateral and contralateral did not change significantly after administration at 300 and 600 s for either phenylephrine or ephedrine (phenylephrine 73%, 73%, 73% and 73%, 73%, 74%; ephedrine 72%, 73%, 73% and 75%, 74%, 74%).

Conclusions

Within this randomized prospective study, MAP correction by either phenylephrine or ephedrine showed to be equally effective in maintaining rSO₂ in patients who underwent CEA.

Clinical Trial Registration ClincalTrials.gov, NCT01451294.

[Cerebral protection from ischaemia during carotid endarterectomy]

The purpose of this study was to assess efficacy of cerebral protection during carotid endarterectomy by means of controlled systemic hypertension in patients presenting with various levels of retrograde pressure in the internal carotid artery. The study enrolled a total of 150 patients subjected to carotid endarterectomy. The operation was carried out under general anaesthesia with artificial pulmonary ventilation and was accompanied by haemodynamic monitoring with invasive control of arterial pressure, as well as primary and additional correction of central haemodynamics. Cerebral perfusion was assessed by measuring retrograde pressure in the internal carotid artery. The retrograde pressure index was calculated, according to which the patients were subdivided into three groups: those with values less than 30, with values from 30 to 39, and with values of 40 and more. Controlled systemic arterial hypertension was used as cerebral protection during the period of cross-clamping of the internal carotid artery, with phenylephrine and norepinephrine administered for this purpose. The parameters of central haemodynamics, time intervals of the operation, and the duration of internal carotid artery cross-clamping in the groups did not statistically differ (p>0.05). A statistically significant difference was revealed in the level of systolic arterial pressure necessary for cerebral protection (p<0.05). There were no cerebral circulation impairments, myocardial infarctions, nor lethal outcomes. A conclusion was drawn that individualized correction of central haemodynamics ensured a sufficient level of collateral compensation of the cerebral blood flow, thus making it possible to refuse from using intraluminal shunts.

Noninvasive continuous arterial pressure monitoring with Clearsight during awake carotid endarterectomy: A prospective observational study

BACKGROUND

Continuous noninvasive blood pressure (CNBP) measurement using the volume-clamp method is a less invasive alternative compared with invasive intra-arterial monitoring for awake patients during carotid endarterectomy (CEA) under regional anaesthesia.

OBJECTIVE

We investigated the agreement of blood pressure (BP) recorded with invasive and CNBP methods during awake CEA.

DESIGN

A prospective observational study for assessing agreement with Bland-Altman plots, agreement-tolerability indices (ATI), concordance and interchangeability.

SETTING

Azienda Ospedaliera Universitaria G. Martino, Messina, a University tertiary referral centre in Italy.

PATIENTS

In 30 consecutive patients, we recorded continuously ipsilateral invasive and noninvasive BPs, from 3 min before carotid cross-clamping to 5 min after unclamping.

MAIN OUTCOME MEASURES

Primary outcome was bias, 95% limits of agreement, ATI, concordance and interchangeability for mean arterial pressure (MAP). Secondary outcomes were agreements for systolic arterial pressure and diastolic arterial pressure. Tracking of changes was assessed with four-quadrant polar plots and the trend interchangeability method. Optimal bias was defined as 5 mmHg or less.

RESULTS

A total of 2672 invasive and CNBP paired measurements (93% of overall data) were analysed, with a median of 92 readings per patient [IQR 76 to 100]. Mean (SD) bias for MAP, systolic arterial pressure and DAP were -6.8 (6.7), -3.0 (9.7) and -9.0 (5.4) mmHg, respectively. The ATIs were 0.88, 0.95 and 0.71, respectively, where ATI of 1.0 or less and at least 2.0 defined acceptable, marginal and unacceptable agreements. The four-quadrant plot analysis for beat-to-beat differences showed concordance rates of 97.3%, 99.98% and 96.4%, respectively. Polar plot analysis showed 95% limits of agreement of -3 to 3, -2 to 2 and -2 to 2 mmHg respectively. Trend interchangeability method showed an interchangeability rate of 95% for MAP.

CONCLUSION

During CEA performed under regional anaesthesia, CNBP offers a less invasive approach for BP monitoring. We found acceptable agreement for MAP defined by an ATI of 0.88 and an excellent 95% global interchangeability rate. A suboptimal bias of 7 mmHg was found with CNBP for MAP.

Perioperative Quality Initiative consensus statement on intraoperative blood pressure, risk and outcomes for elective surgery

BACKGROUND

Intraoperative mortality is now rare, but death within 30 days of surgery remains surprisingly common. Perioperative myocardial infarction is associated with a remarkably high mortality. There are strong associations between hypotension and myocardial injury, myocardial infarction, renal injury, and death. Perioperative arterial blood pressure management was thus the basis of a Perioperative Quality Initiative consensus-building conference held in London in July 2017.

METHODS

The meeting featured a modified Delphi process in which groups addressed various aspects of perioperative arterial pressure.

RESULTS

Three consensus statements on intraoperative blood pressure were established. 1) Intraoperative mean arterial pressures below 60-70 mm Hg are associated with myocardial injury, acute kidney injury, and death. Injury is a function of hypotension severity and duration. 2) For adult non-cardiac surgical patients, there is insufficient evidence to recommend a general upper limit of arterial pressure at which therapy should be initiated, although pressures above 160 mm Hg have been associated with myocardial injury and infarction. 3) During cardiac surgery, intraoperative systolic arterial pressure above 140 mm Hg is associated with increased 30 day mortality. Injury is a function of arterial pressure severity and duration.

CONCLUSIONS

There is increasing evidence that even brief durations of systolic arterial pressure <100 mm Hg and mean arterial pressure <60-70 mm Hg are harmful during non-cardiac surgery.

Simultaneous Multi-Supra-Aortic Artery Bypass Successfully Implemented in 17 Patients with Type I Takayasu Arteritis

OBJECTIVE

Type I Takayasu arteritis is common in Chinese patients and usually leads to cerebral ischaemia. There are limited data regarding simultaneous multi-supra-aortic artery (SMSAA) bypass in patients with type I Takayasu arteritis. The present study shares experience of using this method.

METHODS

Seventeen patients with Takayasu arteritis who received SMSAA bypass from June 2012 to March 2016 were included in this analysis. Demographic features and basic information were recorded. Follow up results, including major complications, patency rates, and survival rates, were also obtained. The EQ-5D questionnaire was also administered to evaluate the quality of life of patients.

RESULTS

Among these 17 patients, there were 77 supra-aortic arteries affected by TA and 37 arteries were reconstructed, 10 with great saphenous vein and 27 with artificial blood vessels. All the operations were technical successes and the mean operation time was 396.6 ± 93.4 min. The patients were followed for a mean of 25.2 ± 12.3 months. Two graft restenoses were found, and both were successfully recanalised by balloon dilatation. One patient suffered a minor stroke but was free from obvious sequelae. No major complications, recurrent symptoms, or deaths occurred during the follow up period. The EQ-5D questionnaire scores were significantly improved after the operation compared with the pre-operative scores (87.14 ± 8.25 vs. 58.93 ± 14.4, p < .01), and all the patients enjoyed a satisfactory quality of life.

CONCLUSION

SMSAA bypass in type I Takayasu arteritis can be effectively and safely performed with rigorous peri-operative management. Maintaining the patency of the bypass graft relieves the symptoms of cerebral ischaemia and helps sustain patients' quality of life.

Easily Screenable Characteristics Associated with Cognitive Improvement and Dysfunction After Carotid Endarterectomy

BACKGROUND

Carotid endarterectomy (CEA) is an effective treatment for the prevention of stroke in patients with carotid artery stenosis. We aimed to clarify the incidence and risk factors for early cognitive dysfunction (eCD) and early cognitive improvement (eCI), defined as change in cognitive performance ≤24 hours after surgery, using a battery of neuropsychometric tests.

METHODS

In total, 585 patients undergoing CEA were tested with neuropsychometric tests before and after surgery; 155 patients undergoing "simple" spine surgery were the reference group. Patient performance for each test was evaluated by z scores. Cognitive change was defined as eCD (or eCI) if: 1) patients had a z score ≤-2 (or ≥2) in ≥2 cognitive domains or 2) patients had mean z scores across all domains ≤-1.5 (or ≥1.5). Associations between the categorical cognitive outcomes and variables of interest were modeled using the proportional odds model.

RESULTS

Of the 585 subjects, 24% had eCD, 6% had eCI, and 70% had "no change." Patients who had eCD were more likely to be statin naïve (odds ratio [OR] 1.23 [1.03-1.48], P = 0.02) or women (OR 1.27 [1.06-1.53], P = 0.02). Those with eCI were less likely to have less formal education (OR 0.95 [0.90-1.00], P = 0.04) and less likely to have diabetes mellitus (OR 0.8 [0.65-0.99], P = 0.04).

CONCLUSIONS

Patients having CEA may develop eCD or eCI postoperatively. Medications likely to be associated with less eCD are statins and aspirin, which correlate most strongly in asymptomatic patients. In addition to confirming previous findings, we found that women were more likely than men to develop eCD. More sex-specific studies and analysis are needed to better explore these findings.

Perioperative hyperglycemia and neurocognitive outcome after surgery: a systematic review

INTRODUCTION

Preliminary evidence suggest a possible relationship between perioperative hyperglycemia, postoperative delirium (POD) or cognitive dysfunction (POCD). We aim to present the available clinical evidence related to chronic (i.e. diabetes mellitus) or acute perioperative hyperglycemia as risk factors for POD/POCD.

EVIDENCE ACQUISITION

A literature search of EMBASE (via Ovid, 1974-present) online medical database and MEDLINE (via PubMed or Ovid, 1946-present) was performed. All types of clinical studies including randomized controlled trials, prospective, as well as retrospective cohort studies were screened. Clinical studies that reported original information on the relationship between diabetes mellitus (DM) and/or acute perioperative abnormal glucose levels and POD or POCD were selected. Reviews and editorials (i.e. articles not presenting original preclinical or clinical research) were excluded and case-reports were not considered for analysis.

EVIDENCE SYNTHESIS

Our search resulted in 2356 papers for screening, from which we selected 29 studies that met our inclusion criteria. DM was investigated in 24 observational papers, acute perioperative hyperglycemia in six observational studies and two randomized controlled trials examined the effect of perioperative glucose lowering on POD/POCD. Diabetes was associated with POD or POCD in 18/24 observational studies and 6/6 of the included observational studies found that perioperative hyperglycemia was associated with POD/POCD, independent of diabetes. The two randomized controlled trials had a different trial design and reported conflicting results.

CONCLUSIONS

According to the available evidence, DM and acute perioperative hyperglycemia may be associated with an increased risk for POD/POCD. These conclusions are based mostly on observational studies and deserve more and dedicated research. This systematic review may direct the design of future studies.

Comparison of Monitoring of Cerebral Blood Flow by c-FLOW and Transcranial Doppler in Carotid Endarterectomy

OBJECTIVE

To prospectively compare the use of the cerebral blood flow monitor (c-FLOW) and transcranial Doppler (TCD) as 2 techniques for assessing brain perfusion during carotid endarterectomy.

METHODS

This was a prospective, single-center, observational study. All patients were monitored using c-FLOW and TCD during the operation. Changes from baseline values of cerebral blood flow index and blood flow velocity of middle cerebral artery (V-MCA) were recorded following carotid artery clamping and unclamping. The correlation analysis was conducted for c-FLOW and TCD monitoring values.

RESULTS

Seventy-three consecutive patients were enrolled from August 2015 to March 2016. No death or stroke occurred during the postoperative hospitalization. Fresh infarction was identified on magnetic resonance imaging in 17 patients. Ten patients showed a significant decrease of V-MCA following carotid clamping. A shunt was placed for only 4. The Pearson correlation index between CFI and V-MCA was 0.647 (P < 0.001). A cut-off of 21% decrease of CFI was proposed as optimal to detect intraoperative hypoperfusion. Seven patients were diagnosed as having hyperperfusion by TCD monitoring. The Pearson correlation index between CFI and V-MCA was 0.286 (P = 0.014). A cut-off of 15% increase of CFI following carotid unclamping was suggested as optimal to detect the postoperative hyperperfusion.

CONCLUSIONS

c-FLOW could continuously and noninvasively monitor the cerebral blood flow in real-time during carotid endarterectomy and effectively detect the intraoperative hypoperfusion and postoperative hyperperfusion as defined by TCD so that it may serve as a favorable modality in future intraoperative monitoring.

Hypertension and Risk of Post-Operative Cognitive Dysfunction (POCD): A Systematic Review and Meta-Analysis

Background:

Post-operative cognitive dysfunction (POCD) occurs frequently after major surgery. Hypertension is well-established as a risk factor for age-related cognitive impairment, but it is unclear whether or not it also increases the risk of POCD.

Objective:

To evaluate the role of hypertension in POCD risk in a systematic review and meta-analysis.

Method:

PubMed, Ovid SP and the Cochrane Database of Systematic Reviews were searched for longitudinal studies of adults undergoing surgery with reporting of hypertension, blood pressure and/or anti-hypertensive treatment associations with POCD as relative risks or odds ratios. Fixed-effects meta-analyses were performed using Review Manager (version 5.3).

Results:

Twenty-four studies on 4317 patients (mean age 63 years) were included. None of the studies had set out to assess hypertension as a risk factor for POCD. Hypertension was used as a categorical predictor throughout and only 2 studies adjusted for potential confounders. Across all 24 studies, hypertension was not significantly associated with POCD risk (RR 1.01; 95% CI 0.93, 1.09; p=0.82), though among 8 studies with >75% males, we found hypertension associations with a 27% increased risk of POCD (RR 1.27, 95% CI 1.07, 1.49; p=0.005).

Conclusion:

Our findings do not support the hypothesis that hypertension is a risk factor for POCD. However, since none of the studies included in our analysis were hypothesis-driven and most did not adjust for potential confounders, further systematic investigations are needed to evaluate the role of hypertension in the epidemiology of POCD.

Spies C, Pischon T. Cognitive Reserve and the Risk of Postoperative Cognitive Dysfunction

BACKGROUND

Post-operative cognitive dysfunction (POCD) occurs in 10 to 54% of older patients during the first few weeks after surgery, but little is known about risk factors predisposing to POCD.

METHODS

Systematic literature review and meta-analysis of cognitive reserve indicators and POCD risk.

RESULTS

Fifteen studies on 5104 patients were included. Follow-up periods spanned 1 day to 6 months. Educational level was the most commonly assessed cognitive reserve indicator, and a longer time spent in education was associated with a reduced risk of POCD (relative risk [RR] per year increment 0.90; 95% confidence interval: [0.87; 0.94]), i.e. each year increase in education was associated with a 10% reduced risk. Similar findings were made for some analyses on education as a categorical predictor (high school versus further/higher education, RR 1.71, [1.30; 2.25]; lower than high school versus further/higher education, RR 1.69, [1.17; 2.44]) though risk was equivalent for patients with high school education and those with lower than high school education (RR 1.02; [0.78; 1.32]).

CONCLUSION

Patients with a relatively higher level of education are at reduced risk of POCD. Risk stratification of surgical patients according to educational level may prove useful.

Atherosclerotic carotid stenosis and cognitive function

Atherosclerosis carotid stenosis is associated with stroke and cognitive impairment. Progressive cognitive decline may be an even greater problem than stroke, but it has not been widely recognized and therefore must be adequately addressed. Although both Carotid Endarterectomy (CEA) and Carotid Artery Stenting (CAS) have been proven can prevent future stroke in patients with atherosclerotic carotid stenosis, the influence of CEA and CAS on cognitive function is not clear. In the first part of this review, we evaluated the literature concerning carotid stenosis and the risk of cognitive impairment. Studies have suggested that both symptomatic and asymptomatic carotid stenosis are associated with cognitive impairment. In the second part, we reviewed the impact of CEA and CAS on cognitive function, some studies have shown benefits, but others have not.

Impact of Cognitive Dysfunction on Survival in Patients With and Without Statin Use Following Carotid Endarterectomy

BACKGROUND:

Early cognitive dysfunction (eCD) is a subtle form of neurological injury observed in ∼25% of carotid endarterectomy (CEA) patients. Statin use is associated with a lower incidence of eCD in asymptomatic patients having CEA.

OBJECTIVE:

To determine whether eCD status is associated with worse long-term survival in patients taking and not taking statins.

METHODS:

This is a post hoc analysis of a prospective observational study of 585 CEA patients. Patients were evaluated with a battery of neuropsychometric tests before and after surgery. Survival was compared for patients with and without eCD stratifying by statin use. At enrollment, 366 patients were on statins and 219 were not. Survival was assessed by using Kaplan-Meier methods and multivariable Cox proportional hazards models.

RESULTS:

Age ≥75 years (P = .003), diabetes mellitus (P &lt; .001), cardiac disease (P = .02), and statin use (P = .014) are significantly associated with survival univariately (P &lt; .05) by use of the log-rank test. By Cox proportional hazards model, eCD status and survival adjusting for univariate factors within statin and nonstatin use groups suggested a significant effect by association of eCD on survival within patients not taking statin (hazard ratio, 1.61; 95% confidence interval, 1.09–2.40; P = .018), and no significant effect of eCD on survival within patients taking statin (hazard ratio, 0.98; 95% confidence interval, 0.59–1.66; P = .95).

CONCLUSION:

eCD is associated with shorter survival in patients not taking statins. This finding validates eCD as an important neurological outcome and suggests that eCD is a surrogate measure for overall health, comorbidity, and vulnerability to neurological insult.

Anaesthesia for carotid endarterectomy - general or loco-regional?

Carotid endarterectomy has been widely used for the surgical treatment of carotid stenosis, and may be performed under either general or loco-regional anaesthesia. The greatest risks of carotid endarterectomy are the neurologic complications and the myocardial infarction. Anaesthetic and surgical techniques are constantly under scrutiny to try to reduce the relatively high incidence of morbidity and mortality of an operation which in itself is only preventative. Loco-regional anaesthesia is an alternative to general anaesthesia which has attracted considerable attention amid claims of a reduction in operative morbidity and mortality. This review describes the problems and some solutions for providing loco-regional or general anaesthesia for carotid endarterectomy.

Regional anaesthesia for carotid endarterectomy

Summary Regional anaesthesia is a popular choice for patients undergoing carotid endarterectomy (CEA). Neurological function is easily assessed during carotid cross-clamping; haemodynamic control is predictable; and hospital stay is consistently shorter compared with general anaesthesia (GA). Despite these purported benefits, mortality and stroke rates associated with CEA remain around 5% for both regional anaesthesia and GA. Regional anaesthetic techniques for CEA have improved with improved methods of location of peripheral nerves including nerve stimulators and ultrasound together with a modification in the classification of cervical plexus blocks. There have also been improvements in local anaesthetic, sedative, and arterial pressure-controlling drugs in patients undergoing CEA, together with advances in the management of patients who develop neurological deficit after carotid cross-clamping. In the UK, published national guidelines now require the time between the patient's presenting neurological event and definitive treatment to 1 week or less. This has implications for the ability of vascular centres to provide specialized vascular anaesthetists familiar with regional anaesthetic techniques for CEA. Providing effective regional anaesthesia for CEA is an important component in the armamentarium of techniques for the vascular anaesthetist in 2014.

Clinical Outcome after Intra-Arterial Stroke Therapy in the Very Elderly: Why is it so Heterogeneous?

Very elderly patients (i.e., ≥80 years) are disproportionally affected by acute ischemic stroke. They account for a third of hospital stroke admissions, but two-thirds of overall stroke-related morbidity and mortality. There is some evidence of clinical benefit in treating selected very elderly patients with intravenous thrombolysis (IVT). For very elderly patients ineligible or non-responsive to IVT, intra-arterial therapy (IAT) may have promise in improving clinical outcome. However, its unequivocal efficacy in the general population remains to be proven in randomized trials. Small cohort studies reveal that the rate of good clinical outcome for very elderly patients after IAT is highly variable, ranging from 0 to 28%. In addition, they experience higher rates of futile reperfusion than younger patients. Thus, it is imperative to understand the factors that impact on clinical outcome in very elderly patients after IAT. The aim of this review is to examine the factors that may be responsible for the heterogeneous clinical response of the very elderly to IAT. This will allow the reader to integrate the current available evidence to individualize intra-arterial stroke therapy in very elderly patients. Placing emphasis on pre-stroke independent living, smaller infarct core size, short procedure times, and avoiding general anesthesia where feasible, will help improve rates of good clinical outcome.