Nasal Intubation is not Associated with "Smoother" Emergence from General Anesthesia for Carotid Endarterectomy: A Case-Cohort Study

BACKGROUND

Postoperative hematoma after carotid endarterectomy (CEA) is a devastating complication and may be more likely in patients with uncontrolled hypertension and coughing on emergence from anesthesia. We sought to determine if intubation with a nasal endotracheal tube (ETT)-instead of an oral ETT-is associated with "smoother" (i.e., less hemodynamic instability) emergence from general anesthesia for CEA.

METHODS

Patients receiving CEA between December 2015 and September 2021 at a single tertiary academic medical center were included. We examined the electronic anesthesia records for 323 patients who underwent CEA during the 6-year study period and recorded consecutive systolic blood pressure (SBP) values during the 10 minutes before extubation as a surrogate for "smoothness" of the emergence.

RESULTS

Intubation with a nasal ETT, when compared with intubation with an oral ETT, was not associated with any difference in maximum, minimum, average, median, or standard deviation of serial SBP values in the 10 minutes before extubation. The average SBP on emergence for patients with an oral ETT was 141 mm Hg and with a nasal ETT was 144 mm Hg (P = 0.562). The maximum SBP for patients with oral and nasal ETTs were 170 mm Hg and 174 mm Hg, respectively (P = 0.491). There were also no differences in the qualitative "smoothness" of emergence or in the percentage of patients who required an intravenous dose of 1 or more antihypertensive medications. The incidence of postoperative complications was similar between the 2 groups.

CONCLUSIONS

When SBP is used as a surrogate for smoothness of emergence from general anesthesia for CEA, intubation with a nasal ETT was not associated with better hemodynamic stability compared to intubation with an oral ETT.

Redefining postoperative hypertension management in carotid surgery: a comprehensive analysis of blood pressure homeostasis and hyperperfusion syndrome in unilateral vs. bilateral carotid surgeries and implications for clinical practice

Background

This study evaluates the implications of blood pressure homeostasis in bilateral vs. unilateral carotid surgeries, focusing on the incidence of postoperative hypertension, hyperperfusion syndrome, and stroke as primary outcomes. It further delves into the secondary outcomes encompassing major adverse cardiovascular events and all-cause mortality.

Methods

Spanning two decades (2002-2023), this comprehensive retrospective research encompasses 15,369 carotid referrals, out of which 1,230 underwent carotid interventions. A subset of 690 patients received open carotid procedures, with a 10-year follow-up, comprising 599 unilateral and 91 bilateral surgeries. The Society for Vascular Surgery Carotid Reporting Standards underpin our methodological approach for data collection. Both univariate and multivariate analyses were utilized to identify factors associated with postoperative hypertension using the Statistical Package for the Social Sciences (SPSS) Version 22 (SPSS®, IBM® Corp., Armonk, N.Y., USA).

Results

A marked acute elevation in blood pressure was observed in patients undergoing both unilateral and bilateral carotid surgeries (p < 0.001). Smoking (OR: 1.183, p = 0.007), hyperfibrinogenemia (OR: 0.834, p = 0.004), emergency admission (OR: 1.192, p = 0.005), severe ipsilateral carotid stenosis (OR: 1.501, p = 0.022), and prior ipsilateral interventions (OR: 1.722, p = 0.003) emerged as significant factors that correlates with postoperative hypertension in unilateral surgeries. Conversely, in bilateral procedures, gender, emergency admissions (p = 0.012), and plaque morphology (p = 0.035) significantly influenced postoperative hypertension. Notably, 2.2% of bilateral surgery patients developed hyperperfusion syndrome, culminating in hemorrhagic stroke within 30 days. Intriguingly, postoperative stage II hypertension was identified as an independent predictor of neurological deficits post-secondary procedure in bilateral CEA cases (p = 0.004), attributable to hyperperfusion syndrome. However, it did not independently predict myocardial infarction or mortality outcomes. The overall 30-day stroke rate stood at 0.90%. Lowest incidence of post operative hypertension or any complications were observed in eversion carotid endartrertomy.

Conclusion

The study identifies postoperative hypertension as a crucial independent predictor of perioperative stroke following bilateral carotid surgery. Moreover, the study elucidates the significant impact of bilateral CEA on the development of post-operative hyperperfusion syndrome or stroke, as compared to unilateral CEA. Currently almost 90% of our carotid practice is eversion carotid endartrerectomy.

Measuring pulsatile cortical blood flow and volume during carotid endarterectomy

Carotid endarterectomy (CEA) involves removal of plaque in the carotid artery to reduce the risk of stroke and improve cerebral perfusion. This study aimed to investigate the utility of assessing pulsatile blood volume and flow during CEA. Using a combined near-infrared spectroscopy/diffuse correlation spectroscopy instrument, pulsatile hemodynamics were assessed in 12 patients undergoing CEA. Alterations to pulsatile amplitude, pulse transit time, and beat morphology were observed in measurements ipsilateral to the surgical side. The additional information provided through analysis of pulsatile hemodynamic signals has the potential to enable the discovery of non-invasive biomarkers related to cortical perfusion.

Short-term outcomes after selective shunt during carotid endarterectomy: a propensity score matching analysis

INTRODUCTION AND OBJECTIVES

Carotid cross-clamping during carotid endarterectomy might lead to intraoperative neurologic deficits, increasing stroke/death risk. If deficits are detected, carotid shunting has been recommended to reduce the risk of stroke. However, shunting may sustain a specific chance of embolic events and subsequently incurring harm. Current evidence is still questionable regarding its clear benefit. The aim is to determine whether a policy of selective shunt impacts the complication rate following an endarterectomy.

MATERIAL AND METHODS

From January 2013 to May 2021, all patients undergoing carotid endarterectomy under regional anesthesia with intraoperative neurologic alteration were retrieved. Patients submitted to selective shunt were compared to a non-shunt group. A 1:1 propensity score matching (PSM) was performed. Differences between the groups and clinical outcomes were calculated, resorting to univariate analysis.

RESULTS

Ninety-eight patients were selected, from which 23 were operated on using a shunt. After PSM, 22 non-shunt patients were compared to 22 matched shunted patients. Concerning demographics and comorbidities, both groups were comparable to pre and post-PSM, except for chronic heart failure, which was more prevalent in shunted patients (26.1%, P=0.036) in pre-PSM analysis. Regarding 30-day stroke and score Clavien-Dindo ≥2, no significant association was found (P=0.730, P=0.635 and P=0.942, P=0.472, correspondingly, for pre and post-PSM).

CONCLUSIONS

In this cohort, resorting to shunting did not demonstrate an advantage regarding 30-day stroke or a Clavien-Dindo ≥ 2 rates. Nevertheless, additional more extensive studies are mandatory to achieve precise results concerning the accurate utility of carotid shunting in this subset of patients under regional anesthesia.

Hemodynamic Safety and Effect of Dexmedetomidine on Superficial Cervical Block Quality for Carotid Endarterectomy: A Prospective Study

OBJECTIVE

Dexmedetomidine as an adjuvant to local anesthetics (LAs) in regional anesthesia has demonstrated a positive effect on the quality of regional blocks, but there are no studies on usage in superficial cervical block (SCB) for carotid endarterectomy (CEA), in which the management of mean arterial pressure is essential. The authors designed a prospective, randomized, double-blinded study to investigate the effects of the addition of dexmedetomidine on the hemodynamic management and quality of SCB.

DESIGN

A prospective, randomized, double-blinded study.

SETTING

A single-center study at a university hospital center.

PARTICIPANTS

Ultrasound-guided SCB was performed on 60 patients classified as American Society of Anesthesiologists Grades II and III undergoing elective CEA surgery who were assigned into 2 groups randomly.

INTERVENTION(S)

Both groups received 2 mg/kg of 0.5% levobupivacaine with 2 mg/kg of 2% lidocaine. The intervention group additionally received 50 μg of dexmedetomidine.

MEASUREMENTS AND MAIN RESULTS

The onset and duration of sensory block and analgesia, hemodynamic parameters, and adverse effects were recorded. There were minimum effects on hemodynamic parameters and no differences in the incidence of adverse effects. The time to first analgesia was longer in the intervention group than in the control group (N = 30). There was no difference in the duration of the sensory block between groups. The log-rank test indicated a significant difference in the probability of the Numeric Pain Rating Scale <3.

CONCLUSION

The addition of 50 μg of dexmedetomidine to 0.5% levobupivacaine and 2% lidocaine for SCB did not influence the hemodynamics and frequency of adverse effects. The median sensory block duration time showed no statistical difference between the groups, but the quality of analgesia postoperatively was much improved in the study group.

Combined Arterial Hypertension and Ischemic Stroke Exaggerate Anesthesia-Related Hypotension and Cerebral Oxygenation Deficits: A Preclinical Study

BACKGROUND

Intraoperative arterial hypotension (IOH) is a common side effect of general anesthesia (GA), associated with poor outcomes in ischemic stroke. While IOH is more prevalent with hypertension, it is unknown whether IOH may differ when GA is induced during ischemic stroke, versus other clinical settings. This is important given that many stroke patients receive GA for endovascular thrombectomy.

METHODS

We evaluate the cardiovascular responses to volatile GA (isoflurane in 100% o2 ) before and during middle cerebral artery occlusion stroke in rats instrumented to record blood pressure (BP) and cerebral tissue oxygenation (p o2 ) in the projected penumbra, in clinically relevant cohorts of normotensive (Wistar rat, n = 10), treated hypertensive (spontaneously hypertensive [SH] + enalapril, n = 12), and untreated hypertensive (SH rat, n = 12).

RESULTS

During baseline induction of GA, IOH was similar in normotensive, treated hypertensive, and untreated hypertensive rats during the induction phase (first 10 minutes) (-24 ± 15 vs -28 ± 22 vs -48 ± 24 mm Hg; P > .05) and across the procedure (-24 ± 13 vs -30 ± 35 vs -39 ± 27 mm Hg; P > .05). Despite the BP reduction, cerebral p o2 increased by ~50% in all groups during the procedure. When inducing GA after 2 hours, all stroke groups showed a greater magnitude IOH compared to baseline GA induction, with larger falls in treated (-79 ± 24 mm Hg; P = .0202) and untreated(-105 ± 43 mm Hg; P < .001) hypertensive rats versus normotensives (-49 ± 21 mm Hg). This was accompanied by smaller increases in cerebral p o2 in normotensive rats (19% ± 32%; P = .0144 versus no-stroke); but a decrease in cerebral p o2 in treated (-11% ± 19%; P = .0048) and untreated (-12% ± 15%; P = .0003) hypertensive rats. Sham animals (normotensive and hypertensive) showed similar magnitude and pattern of IOH when induced with GA before and after sham procedure.

CONCLUSIONS

Our findings are the first demonstration that ischemic stroke per se increases the severity of IOH, particularly when combined with a prior history of hypertension; this combination appears to compromise penumbral perfusion.

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.

The Gupta Perioperative Risk for Myocardial Infarct or Cardiac Arrest (MICA) Calculator as an Intraoperative Neurologic Deficit Predictor in Carotid Endarterectomy

Background: Patients undergoing carotid endarterectomy (CEA) may experiment intraoperative neurologic deficits (IND) during carotid cross-clamping. This work aimed to assess the impact of the Gupta Perioperative Myocardial Infarct or Cardiac Arrest (MICA) risk calculator in the IND. Methods: From January 2012 to April 2021, patients undergoing CEA with regional anaesthesia for carotid stenosis with IND and consecutively control operated patients without IND were selected. A regressive predictive model was created, and a receiver operating characteristic (ROC) curve was applied for comparison. A multivariable dependence analysis was conducted using a classification and regression tree (CRT) algorithm. Results: A total of 97 out of 194 included patients developed IND. Obesity showed aOR = 4.01 (95% CI: 1.66–9.67) and MICA score aOR = 1.21 (1.03–1.43). Higher contralateral stenosis showed aOR = 1.29 (1.08–1.53). The AUROC curve was 0.656. The CRT algorithm differentiated obese patients with a MICA score ≥ 8. Regarding non-obese patients, the model identified the presence of contralateral stenosis ≥ 55% with a MICA ≥ 10. Conclusion: MICA score might play an additional role in stratifying patients for IND in CEA. Obesity was determined as the best discrimination factor, followed by a score ≥ 8. A higher ipsilateral stenosis degree is suggested to have a part in avoiding procedure-related IND. Larger studies might validate the benefit of MICA score regarding the risk of IND.

Preoperative evaluation and perioperative management of patients undergoing major vascular surgery

Patients undergoing major vascular surgery have an increased risk of perioperative major adverse cardiovascular events (MACE). Accordingly, in this population, it is of particular importance to appropriately risk stratify patients' risk for these complications and optimize risk factors prior to surgical intervention. Comorbidities that portend a higher risk of perioperative MACE include coronary artery disease, heart failure, left-sided valvular heart disease, and significant arrhythmic burden. In this review, we provide a current approach to risk stratification prior to major vascular surgery and describe the strengths and weaknesses of different cardiac risk indices; discuss the role of noninvasive and invasive cardiac testing; and review perioperative pharmacotherapies.

Intraoperative Transcranial Doppler Monitoring Predicts the Risk of Cerebral Hyperperfusion Syndrome After Carotid Endarterectomy

OBJECTIVE

Cerebral hyperperfusion syndrome (CHS) is a rare but serious complication following carotid endarterectomy (CEA). The aim of this study was to identify intraoperative transcranial Doppler (TCD) hemodynamic predictors of CHS after CEA.

METHODS

Between January 2013 and December 2018, intraoperative TCD monitoring was performed for 969 patients who underwent CEA. The percentage increase in the mean velocity of the middle cerebral artery (MCAV%) at 3 postdeclamping time points (immediately after declamping, 5 minutes after declamping, and after suturing the skin) over baseline was compared between CHS and non-CHS patients.

RESULTS

CHS was diagnosed in 31 patients (3.2%), including 11 with intracranial hemorrhage. The MCAV% values at the 3 postdeclamping time points over baseline were 177% (81%-275%), 90% (41%-175%), and 107% (55%-191%) in the CHS group, significantly higher than those in the non-CHS group (40% [14%-75%], 15% [1%-36%], and 18% [3%-41%], respectively, all P < 0.001). Receiver operating characteristic curve analysis showed that the 3 intraoperative MCAV% parameters all had excellent accuracy in identifying CHS (areas under the curve: 0.854, 0.839, and 0.858, respectively, all P < 0.001). The predictive value of the model consisting only of preoperative parameters was significantly increased by adding the intraoperative TCD hemodynamic parameters (area under the curve: 0.747 vs. 0.858, P = 0.006). Multivariate analyses identified the intraoperative MCAV% immediately after declamping (odds ratio: 9.840, 95% confidence interval: 2.638-36.696, P < 0.001) as an independent predictor of CHS.

CONCLUSIONS

Our results indicate that intraoperative TCD monitoring helps predict CHS after CEA at an early stage.

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.

Incidence of postoperative, major, adverse cardiac events in patients undergoing carotid endarterectomy: A single-center, retrospective study

OBJECTIVE

This study aimed to determine the incidence of postoperative major adverse cardiac events for patients undergoing carotid endarterectomy.

METHODS

This single-center, retrospective study recruited 171 carotid endarterectomy patients between January 1999 and June 2018. Patients who received a carotid endarterectomy in conjunction with other surgery were excluded. The primary outcomes were the incidences of major adverse cardiac events (comprising myocardial infarction, significant arrhythmias, congestive heart failure, and cardiac death) within 7 days, 7-30 days, and > 30 days-1 year, postoperatively. The secondary outcomes were the factors related to major adverse cardiac events and the incidence of postoperative stroke. The patients' charts were reviewed, and direct contact was made with them to obtain information on their status post discharge.

RESULTS

The incidences of major adverse cardiac events within 7 days, 7-30 days, and >30 days-1 year of the carotid endarterectomy were 3.5% of patients (95% confidence interval: 0.008-0.063), 1.2% (95% confidence interval: 0.004-0.028), and 1.8% (95% confidence interval: 0.002-0.037), respectively. The major adverse cardiac events occurring within 7 days were arrhythmia (2.3% of patients), cardiac arrest (1.8%), myocardial infarction (1.2%), and congestive heart failure (1.2%), while the corresponding postoperative stroke rate was 4.7%.

CONCLUSION

The 7-day incidence of major adverse cardiac events after the carotid endarterectomy was 3.5%. The most common major adverse cardiac event during that period was cardiac arrhythmia.

Cerebral and Systemic Stress Parameters in Correlation with Jugulo-Arterial CO2 Gap as a Marker of Cerebral Perfusion during Carotid Endarterectomy

Intraoperative stress is common to patients undergoing carotid endarterectomy (CEA); thus, impaired oxygen and metabolic balance may appear. In this study, we aimed to identify new markers of intraoperative cerebral ischemia, with predictive value on postoperative complications during CEA, performed in regional anesthesia. A total of 54 patients with significant carotid stenosis were recruited and submitted to CEA. Jugular and arterial blood samples were taken four times during operation, to measure the jugulo-arterial carbon dioxide partial pressure difference (P(j-a)CO₂), and cortisol, S100B, L-arginine, and lactate levels. A positive correlation was found between preoperative cortisol levels and all S100B concentrations. In addition, they are positively correlated with P(j-a)CO₂ values. Conversely, postoperative cortisol inversely correlates with P(j-a)CO₂ and postoperative S100B values. A negative correlation was observed between maximum systolic and pulse pressures and P(j-a)CO₂ after carotid clamp and before the release of clamp. Our data suggest that preoperative cortisol, S100B, L-arginine reflect patients' frailty, while these parameters postoperatively are influenced by intraoperative stress and injury. As a novelty, P(j-a)CO₂ might be an emerging indicator of cerebral blood flow during CEA.

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.

Influence of Eversion Endarterectomy and Patch Reconstruction on Postoperative Blood Pressure After Carotid Surgery

BACKGROUND

Post carotid blood pressure fluctuation and hypertension (PEH) are associated with increased risk for adverse outcome; there is limited evidence on the impact of eversion endarterectomy (E-CEA) versus conventional endarterectomy with patch closure (C-CEA) on postoperative blood pressure course.

PATIENTS AND METHODS

In this retrospective observational study, 859 consecutive carotid endarterectomy procedures between 2004 and 2014 (C-CEA n = 585 vs. E-CEA n = 274), were evaluated. Pre- and postoperative blood pressure values were recorded from recovery room until third postoperative day and compared between both techniques; influences on the dichotomous target variable "at least one postoperative blood pressure peak", that is need for postoperative vasodilators, were analyzed by a logistic regression model. Influences on postoperative systolic blood pressure were evaluated by a linear mixed effects regression model.

RESULTS

Preoperative baseline blood pressure was not different between both comparison groups. During postoperative course, significantly increased mean systolic blood pressure values in the E-CEA group from recovery room to second postoperative day (recovery room C-CEA: 129.2 mm Hg vs. E-CEA: 136.5 mm Hg; P < 0.001; first postoperative day C-CEA: 132.4 mm Hg vs. E-CEA: 139.3 mm Hg; P = 0.0002; second postoperative day C-CEA: 138.6 mm Hg vs. E-CEA: 143.1 mm Hg; P = 0.023) were observed. No hyperperfusion syndrome was detected as wells as no difference in postoperative complication rate. Frequency of antihypertensive interventions was also elevated in E-CEA group (C-CEA 22.1 % vs. E-CEA 31.8 %; P = 0.003). E-CEA (OR 1.591, 95% CI [1.146; 2.202]; P = 0.005) and presence of preoperatively elevated systolic readings (OR 1.015, 95%CI [1.006;1.024]; P < 0.001) was also associated with increased need for antihypertensive interventions.

CONCLUSION

E-CEA was associated with significantly elevated postoperative blood pressure, compared to C-CEA. C-CEA was associated with postoperative blood pressure decrease; however, no difference as to neurologic and surgical complications was detected between both surgical techniques in clinical practice.

Variation in perioperative cerebral and hemodynamic monitoring during carotid endarterectomy

BACKGROUND

Hemodynamic disturbances cause half of the perioperative strokes following carotid endarterectomy (CEA). Guidelines strongly recommend strict pre- and postoperative blood pressure (BP) monitoring in CEA patients, but do not provide firm practical recommendations. Although in the Netherlands 50 centres perform CEA, no national protocol on perioperative hemodynamic, and cerebral monitoring exists. To assess current monitoring policies of all Dutch CEA-centres, a national survey was conducted.

METHODS

Between May and July 2017 all 50 Dutch CEA-centres were invited to complete a 42-question survey addressing perioperative hemodynamic and cerebral monitoring during CEA. Nonresponders received a reminder after 1 and 2 months. By November 2017 the survey was completed by all centres.

RESULTS

Preoperative baseline BP was based on a single bilateral BP-measurement at the outpatient-clinic in the majority of centres (n = 28). In 43 centres (86%) pre-operative monitoring (transcranial Doppler (TCD, n = 6), electroencephalography (EEG, n = 11), or TCD + EEG (n = 26)) was performed as a baseline reference. Intraoperatively, large diversity for type of anaesthesia (general: 45 vs. local [LA]:5) and target systolic BP (>100 mm hg - 160 mm hg [n = 12], based on preoperative outpatient-clinic or admission BP [n = 18], other [n = 20]) was reported. Intraoperative cerebral monitoring included EEG + TCD (n = 28), EEG alone (n = 13), clinical neurological examination with LA (n = 5), near-infrared spectroscopy with stump pressure (n = 1), and none due to standard shunting (n = 3). Postoperatively, significant variation was reported in standard duration of admission at a recovery or high-care unit (range 3-48 hr, mean:12 hr), maximum accepted systolic BP (range >100 mm hg - 180 mm Hg [n = 32]), postoperative cerebral monitoring (standard TCD [n = 16], TCD on indication [n = 5] or none [n = 24]) and in timing of postoperative cerebral monitoring (range directly postoperative - 24 hr postoperative; median 3 hr).

CONCLUSIONS

In Dutch centres performing CEA the perioperative hemodynamic and cerebral monitoring policies are widely diverse. Diverse policies may theoretically lead to over- or under treatment. The results of this national audit may serve as the baseline dataset for development of a standardized and detailed (inter)national protocol on perioperative hemodynamic and cerebral monitoring during CEA.

Janus Kinase 3 Deficiency Promotes Vascular Reendothelialization-Brief Report

[Figure: see text].

Red blood cell distribution width is associated with hypoperfusion in carotid endarterectomy under regional anesthesia

BACKGROUND

A subset of patients submitted to carotid endarterectomy under regional anesthesia develop intraoperative neurologic deficit during carotid artery crossclamping related to critical cerebral perfusion, which may be owing to low flow or embolic phenomena. This subgroup is deemed prone to worse outcomes, which highlights its clinical relevance. The main aim of this study was to identify clinical and hematological predictors for intraoperative neurologic deficit. The secondary aim was to evaluate the perioperative prognostic value of postcarotid artery crossclamping manifestations of cerebral ischemia.

METHODS

Between January 2012 to January 2020, patients submitted to carotid endarterectomy under regional anesthesia in a tertiary referral center who presented intraoperative neurologic deficit were prospectively and consecutively included. This group constituted 8% of the total carotid endarterectomy performed in the center during this timeframe. The control group of patients was the subsequent patient submitted to carotid endarterectomy without intraoperative neurologic deficit in a 1:1 ratio. Blood samples were collected before surgery (<2 weeks). Propensity score matching was used to identify well-matched pairs of patients.

RESULTS

A total of 180 patients were included, with 90 (50% of the cohort and 8% of total carotid endarterectomies) presenting intraoperative neurologic deficit associated to clamping. Mean age was 71.4 ± 9.27 years in the study group and 68.8 ± 8.36 years in the control group. The clinical variables presenting significance after multivariate analysis include: age (adjusted odds ratio: 1.04, 5-95% confidence interval, [1.003-1.078]; P = .034), obesity (adjusted odds ratio: 3.537 [1.445-8.658]; P = .006), lower ipsilateral carotid stenosis grade (adjusted odds ratio: 0.725 [0.525-0.997]; P = .049), and higher contralateral carotid stenosis grade (adjusted odds ratio: 1.266 [1.057-1.516]; P = .010). Red cell distribution width coefficient of variation demonstrated statistical significance in predicting intraoperative neurologic deficit with an adjusted odds ratio of 1.394 (1.076-1.805); P = .012. The 30-day stroke rate was significantly higher in the intraoperative neurologic deficit group, with an adjusted odds ratio of 5.13 (5-95% confidence interval [1.058-24.87]; P = .042) after propensity score matching. Postoperative complications (Clavien-Dindo ≥2) were also associated with intraoperative neurologic deficit (after propensity score matching adjusted odds ratio of 2.748 [5-95% confidence interval, 0.976-7.741]; P = .051).

CONCLUSION

In this study, increased red cell distribution width coefficient of variation demonstrated value to predict intraoperative neurologic deficit. Additionally, age, obesity, a lower degree of ipsilateral carotid stenosis, and a higher degree of contralateral carotid stenosis also demonstrated ability to predict intraoperative neurologic deficit. Moreover, intraoperative neurologic deficit was an independent risk factor for 30-day stroke and postoperative complications Clavien-Dindo ≥2.

Impact of intraoperative neurologic deficits in carotid endarterectomy under regional anesthesia

OBJECTIVE

Patients undergoing carotid endarterectomy (CEA) may experiment neurologic deficits during the carotid cross-clamping due to secondary cerebral hypoperfusion. An associated risk of postoperative stroke incidence is also well established. This work aimed to assess the postoperative adverse events related to neurologic deficits in the awake test after clamping and to determine its predictive factors. Methods. From January 2012 to January 2018, 79 patients from a referral hospital that underwent CEA with regional anesthesia for carotid stenosis and manifested neurologic deficits were gathered. Consecutively selected controls (n = 85) were submitted to the same procedure without developing neurological changes. Postoperative complications such as stroke, myocardial infarction, all-cause death, and Clavien-Dindo classification were assessed 30 days after the procedure. Univariate and binary logistic regressions were performed for data assessment. Results. Patients with clamping associated neurologic deficits were significantly more obese than the control group (aOR = 9.30; 95% CI: 2.57-33.69; p = .01). Lower degree of ipsilateral stenosis and higher degree of contralateral stenosis were independently related to clamping intolerance (aOR = 0.70; 95% CI: 0.49-0.99; p = .047 and aOR = 1.30; 95% CI: 1.06-1.50; p = .009, respectively). Neurologic deficits were a main 30-day stroke predictor (aOR = 4.30; 95% CI: 1.10-16.71; p = .035). Conclusions. Neurologic deficits during carotid clamping are a predictor of perioperative stroke. Body mass index > 30 kg/m², a lower degree of ipsilateral stenosis, and a higher degree of contralateral stenosis are independent predictors of neurologic deficits and, therefore, might play a role in the prevention of procedure-related stroke.

Cerebrovacular Reserve Predicts the Cerebral Hyperperfusion Syndrome After Carotid Endarterectomy

BACKGROUND

Cerebral hyperperfusion syndrome is a rare but potentially severe complication of carotid artery revascularisation that develops under conditions of resistant postoperative hypertension and impaired cerebrovascular autoregulation.

OBJECTIVE

Was to determine which preoperative and operative factors affect the development of cerebral hyperperfusion syndrome after carotid endarterectomy.

METHODS

This prospective observational study enrolled 93 asymptomatic patients who underwent carotid endarterectomy. Cerebral hyperperfusion was registered in patients who had 100% postoperative increase in mean flow in middle cerebral artery registered by Transcranial Doppler ultrasound. Cerebral hyperperfusion syndrome was diagnosed in patients with cerebral hyperperfusion who postoperatively developed at least one of the symptoms. Pre-operative and operative risk factors for cerebral hyperperfusion syndrome were analysed by multivariate binary logistic regression.

RESULTS

Out of 93 operated patients, cerebral hyperperfusion was registered in 23 and cerebral hyperperfusion syndrome in 18 patients. Risk factors for cerebral hyperperfusion syndrome were included in the binary logistic regression model. Incomplete Circle of Willis morphology on 3D TOF magnetic resonance image (p = 0.002), Breath holding index below the 0.69 cut-off (p = 0.006), positive criteria for insufficient collateral flow through circle of Willis registered by TCD (p = 0.03), and poorly controlled hypertension (p = 0.023) showed statistically significant independent predictive value for cerebral hyperperfusion syndrome. The model was statistically significant (p = 0.012) and correctly classified 90.3 % of patients.

CONCLUSIONS

Incomplete circle of Willis and insufficient collateral flow, low cerebrovascular reserve, and poorly regulated hypertension are significant predictors of post- carotid endarterectomy hyperperfusion development.

Perioperative baseline -blockers: An independent protective factor for post-carotid endarterectomy hypertension

OBJECTIVE

Post-carotid endarterectomy hypertension is a well-recognized phenomenon closely related to surgical complications. This study aimed to determine whether different kinds of perioperative antihypertensive drugs had a protective effect on post-carotid endarterectomy hypertension and influence on intraoperative hemodynamics.

METHOD

We retrospectively investigated 102 carotid stenosis patients who underwent conventional endarterectomy with a perioperative baseline antihypertensive regimen. Post-carotid endarterectomy hypertension was defined as a postoperative peak systolic blood pressure ≥160 mmHg and/or a requirement for any additional antihypertensive therapies. We compared the clinical characteristics and types of baseline perioperative antihypertensive drugs between patients with and without post-carotid endarterectomy hypertension and then determined the significant independent effect of antihypertensive drugs on post-carotid endarterectomy hypertension through multivariate regression and detected their influence on intraoperative hypertension (induction-related systolic blood pressure and vasodilators consumption) and hemodynamic depression (intra-arterial systolic blood pressure ≤100 mmHg and/or heart rate ≤50 beats/min). We also investigated adverse events such as stroke, death, myocardial infarction, and cerebral hyperperfusion syndrome during the postoperative hospitalization.

RESULTS

A total of 52/102 (51.0%) patients were defined as having post-carotid endarterectomy hypertension during the first three days postoperative, including eight patients with a postoperative systolic blood pressure that exceeded 160 mmHg at least once, 31 patients requiring postoperative antihypertensive treatment in addition to their baseline regimen, and 13 patients with both. The incidence of stroke/death/myocardial infarction and cerebral hyperperfusion syndrome after conventional endarterectomy during hospitalization were both 1.9%. A significantly increased risk of composite postoperative complications (including cerebral hyperperfusion syndrome, hyperperfusion-related symptoms, transient ischemic attacks, stroke, death, and cardiac complications) was observed in patients with post-carotid endarterectomy hypertension than without (15.4% versus 2.0%, p = 0.032). Patients free of post-carotid endarterectomy hypertension had a higher incidence of perioperative baseline β-blocker use than patients who suffered from post-carotid endarterectomy hypertension (46.0% versus 21%, p = 0.008). In multivariate analysis, β-blocker use was a significant independent protective factor for post-carotid endarterectomy hypertension (OR = 0.356, 95% CI: 0.146-0.886, p = 0.028). Patients taking β-blockers had a lower postoperative peak systolic blood pressure than the β-blocker-naïve population (137.1 ± 12.1 mmHg versus 145.0 ± 11.2 mmHg, p = 0.008), but the postoperative mean systolic blood pressure showed no intergroup difference. However, the incidence of hemodynamic depression during conventional endarterectomy was higher in patients with perioperative β-blocker use than in those without (44.1% versus 25.0%, p = 0.050). The difference in intraoperative hemodynamic depression became more prominent between the β-blocker and non-β-blocker groups (81.8% versus 33.3%, p = 0.014) for whose preoperative baseline heart rate was equal to or lower than 70 beats/min.

CONCLUSION

The perioperative use of β-blockers is a protective factor for post-carotid endarterectomy hypertension and contributes to stabilizing the postoperative peak systolic blood pressure three days after conventional endarterectomy. However, β-blockers might also lead to intraoperative hemodynamic depression, especially for patients with a low baseline heart rate.

Risk Factors for Postoperative Hypotension and Hypertension following Carotid Endarterectomy

BACKGROUND

Patients undergoing carotid endarterectomy (CEA) often experience postoperative hemodynamic changes that require intravenous medications for hypo- and hypertension. Prior studies have found these changes to be associated with increased risks of 30-day mortality, stroke, myocardial infarction (MI), and length of stay (LOS). Our aim is to investigate preoperative risk factors associated with the need for postoperative intravenous medications for blood pressure control.

METHODS

A retrospective review of an internally maintained prospective database of patients undergoing carotid interventions between January 2014 and March 2019 was performed. Demographic data, clinical history, and perioperative data were recorded. Carotid artery stents and reinterventions were excluded. Our primary end points were the need to intervene with intravenous medication for either postoperative hypotension [systolic blood pressure (SBP) <100 mm Hg] or postoperative hypertension (SBP >160 mm Hg).

RESULTS

A total of 221 patients were included in the study after excluding those with a prior ipsilateral CEA or carotid artery stent. The mean age was 72.3 (±8.9) years, 157 (71%) patients were male, and 78 (35.3%) were Caucasian. Following CEA, 151 (68.3%) patients were normotensive, while 33 (14.9%) and 37 (16.7%) required medication for hypotension and hypertension, respectively. A univariate logistic regression identified 5 variables as being associated with postoperative blood pressure including race, history of MI, prior percutaneous transluminal coronary angioplasty (PTCA), statin use, and angiotensin-converting enzyme-inhibitor/angiotensin-receptor blocker (ARB) use. A stepwise regression selection found race, prior MI, and statin use to be associated with our primary end points. The hypertensive group was more likely to have a history of MI compared to the hypotensive and normotensive groups (40.5% vs. 27.3% vs. 18.5%, P = 0.02), PTCA (43.2% vs. 39.4% vs. 23.8%, P = 0.03), and statin use (94.6% vs. 93.9% vs. 78.8%, P = 0.01). Mean LOS was also the highest for the hypertensive group, followed by hypotensive and normotensive patients [2.0 (±1.6) vs. 1.8 (±2.4) vs. 1.3 (±0.8), P = 0.002]. Multivariable logistic regression demonstrated that non-Caucasian patients [odds ratio (OR) 2.72, 95% confidence interval (CI) 1.26-5.86, P = 0.01] and those with a history of MI (OR 2.98, 95% CI 1.33-6.67) were more likely to have postoperative hypertension compared to patients who were Caucasian or had no history of MI.

CONCLUSIONS

Postoperative hypertension is associated with non-Caucasian race and a history of MI. Given the potential implications for adverse perioperative outcomes including MI, mortality, and LOS, it is important to continue to elucidate potential risk factors in order to further tailor the perioperative management of patients undergoing CEA.

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.

Benefit of selective shunt use during carotid endarterectomy under regional anesthesia

Objectives

Carotid cross-clamping during endarterectomy exposes the patient to intraoperative neurological deficits due to embolism or cerebral hypoperfusion. To prevent further cerebrovascular incidents, resorting to shunt is frequently recommended. However, since this method is also considered a stroke risk factor, the use is still controversial. This study aims to shed some light on the best approach regarding the use of shunt in symptomatic cerebral malperfusion after carotid artery cross-clamping.

Methods

From January 2012 to January 2018, 79 patients from a tertiary referral hospital who underwent carotid endarterectomy with regional anesthesia for carotid artery stenosis and manifested post-clamping neurologic deficits were prospectively gathered. Shunt use was left to the decision of the surgeon and performed in 31.6% (25) of the patients. Demographics, comorbidities, imaging tests, and clinical/intraoperative features were evaluated. For data assessment, univariate analysis was performed.

Results

Regarding 30-day stroke, 30-day postoperative complications (stroke, surgical hematoma, hyperperfusion syndrome), and cranial nerve injury, no significant differences were found ( P = 0.301, P = 0.460, and P = 0.301, respectively) between resource to shunt and non-shunt. Clamping and surgery times were significantly higher in the shunt group ( P < 0.001 and P = 0.0001, respectively).

Conclusions

Selective-shunting did not demonstrate superiority for patients who developed focal deficits regarding stroke or other postoperative complications. However, due to the limitations of this study, the benefit of shunting cannot be excluded. Further randomized trials are recommended for precise results on this matter with current sparse clinical evidence.

Pathophysiological and clinical considerations in the perioperative care of patients with a previous ischaemic stroke: a multidisciplinary narrative review

With an ageing population and increasing incidence of cerebrovascular disease, an increasing number of patients presenting for routine and emergency surgery have a prior history of stroke. This presents a challenge for pre-, intra-, and postoperative management as the neurological risk is considerably higher. Evidence is lacking around anaesthetic practice for patients with vascular neurological vulnerability. Through understanding the pathophysiological changes that occur after stroke, insight into the susceptibilities of the cerebral vasculature to intrinsic and extrinsic factors can be developed. Increasing understanding of post-stroke systemic and cerebral haemodynamics has provided improved outcomes from stroke and more robust secondary prevention, although this knowledge has yet to be applied to our delivery of anaesthesia in those with prior stroke. This review describes the key pathophysiological and clinical considerations that inform clinicians providing perioperative care for patients with a prior diagnosis of stroke.

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.

Technical improvements in carotid revascularization based on the mechanism of procedural stroke

The benefit of carotid revascularization in patients with severe carotid artery stenosis is hampered by the risk of stroke due to the intervention itself. The risk of periprocedural strokes is higher for carotid artery stenting (CAS) as compared to carotid endarterectomy (CEA). Over the past years, the pathophysiological mechanism responsible for periprocedural stroke seems to unfold step by step. Initially, all procedural strokes were thought to be the result of technical errors during surgical repair: cerebral ischemia due to clamping time of the carotid artery, cerebral embolization of atherosclerotic debris due to manipulation of the atheroma or thrombosis of the artery. Following improvements in surgical techniques, technical skills, new intraoperative monitoring technologies such as angioscopy, and the results of the first large clinical randomized controlled trials (RCT) it was believed that most periprocedural strokes were of thromboembolic nature, while a large part of these caused by technical error. Nowadays, analyses of underlying pathophysiological mechanisms of procedural stroke make a clinically relevant distinction between intra-procedural and postprocedural strokes. Intra-procedural stroke is defined as hypoperfusion due to clamping (CEA) or dilatation (CAS) and embolization from the carotid plaque (both CEA and CAS). Postprocedural stroke can be caused by thrombo-embolisation but seems to have a primarily hemodynamic origin. Besides thrombotic occlusion of the carotid artery, cerebral hyperperfusion syndrome (CHS) due to extensively increased cerebral revascularization is the most reported pathophysiological mechanism of postprocedural stroke. Multiple technical improvements have attempted to lower the risk of periprocedural stroke. The introduction of antiplatelet therapy (APT) has significantly reduced the risk of thromboembolic events in patients with carotid stenosis. Over the years, recommendations regarding APT changed. While for a long time APT was discontinued prior to surgery because of a fear of increased bleeding risk, nowadays continuation of APT during carotid intervention (aspirin monotherapy or even dual APT including clopidogrel) is found to be safe and effective. In CAS patients, dual APT up to three months' postprocedural is considered best. Stent design and cerebral protection devices (CPD) for CAS procedure are continuously under development. Trials have suggested a benefit of closed-cell stent design over open-cell stent design in order to reduce procedural stroke, while the benefit of CPD during stenting is still a matter of debate. Although CPD reduce the risk of procedural stroke, a higher number of new ischemic brain lesions detected on diffusion weighted imaging was found in patients treated with CPD. In patients undergoing CEA under general anesthesia, adequate use of cerebral monitoring (EEG and transcranial Doppler [TCD]) has reduced the number of intraoperative stroke by detecting embolization and thereby guiding the surgeon to adjust his technique or to selectively shunt the carotid artery. In addition, TCD is able to adequately identify and exclude patients at risk for CHS. For CAS, the additional value of periprocedural cerebral monitoring to prevent strokes needs urgent attention. In conclusion, this review provides an overview of the pathophysiological mechanism of stroke following carotid revascularization (both CAS and CEA) and of the technical improvements that have contributed to reducing this stroke risk.

Anesthesia type determines risk of cerebral infarction after carotid endarterectomy

OBJECTIVE

Silent and symptomatic cerebral infarctions occur in up to 34% of patients after carotid endarterectomy (CEA). This prospective study compared the risk of new brain infarctions detected by magnetic resonance imaging (MRI) in patients with internal carotid artery stenosis undergoing CEA with local anesthesia (LA) vs general anesthesia (GA).

METHODS

Consecutive patients with internal carotid artery stenosis indicated for CEA were screened at two centers. Patients without contraindication to LA or GA were randomly allocated to the LA or GA group by ZIP code randomization. Brain MRI was performed before and 24 hours after CEA. Neurologic examination was performed before and 24 hours and 30 days after surgery. The occurrence of new infarctions on the control magnetic resonance images, stroke, transient ischemic attack, and other complications was statistically evaluated.

RESULTS

Of 210 randomized patients, 105 underwent CEA with LA (67 men; mean age, 68.3 ± 8.1 years) and 105 with GA (70 men; mean age, 63.4 ± 7.5 years). New infarctions were more frequently detected on control magnetic resonance images in patients after CEA under GA compared with LA (17.1% vs 6.7%; P = .031). Stroke or transient ischemic attack occurred within 30 days of CEA in three patients under GA and in two under LA (P = 1.000). There were no significant differences between the two types of anesthesia in terms of the occurrence of other complications (14.3% for GA and 21.0% for LA; P = .277).

CONCLUSIONS

The risk of silent brain infarction after CEA as detected by MRI is higher under GA than under LA.

Post-carotid Endarterectomy Hypertension. Part 2: Association with Peri-operative Clinical, Anaesthetic, and Transcranial Doppler Derived Parameters

OBJECTIVE/BACKGROUND

The first paper in this series observed that pre-operative baroreceptor dysfunction and poorly controlled hypertension were independently predictive for identifying patients who went on to require treatment for post-endarterectomy hypertension (PEH). The second paper examines the influence of intra-operative patient, transcranial Doppler (TCD) ultrasound, and anaesthetic variables on the incidence of PEH.

METHODS

In total, 106 patients underwent carotid endarterectomy (CEA) under general anaesthesia. Systolic blood pressure (SBP) changes, anaesthetic and vasoactive agents, analgesia, and post-operative pain scores, as well as TCD derived changes in middle cerebral artery (MCA) velocity during surgery were recorded. Patients who met pre-existing unit criteria for treating PEH after CEA (SBP > 170 mmHg without symptoms or SBP > 160 mmHg with headache/seizure/neurological deficit) were treated according to an established and validated protocol.

RESULTS

In total, 40/106 patients (38%) required treatment for PEH following CEA (26 in theatre recovery [25%], 27 back on the vascular surgery ward [25%]), whereas seven (7%) had SBP surges > 200 mmHg on the ward. Patients requiring treatment for PEH had significantly higher pre-induction SBP (174 ± 21 mmHg vs. 153 ± 21 mmHg; p < .001), the greatest decreases in SBP after induction of anaesthesia (median decrease 100 ± 32 mmHg vs. 83 ± 24 mmHg; p = .01) and were significantly more likely to experience moderate/severe pain scores post-operatively (p = .003). Logistic regression analysis of the pre- and intra-operative data revealed that higher pre-induction mean SBP and lower pre-operative (impaired) BRS were the only independent predictors of PEH.

CONCLUSION

This analysis of intra-operative variables has demonstrated that patients with poorly controlled and/or labile hypertension at induction of general anaesthesia were those at greatest risk of requiring treatment for PEH in the post-operative period after CEA. No other variables, including use of vasopressors, treatment of hypotension, anaesthetic agents, or changes in MCA velocity after clamp release and restoration of flow were able to predict who might go on to require treatment for PEH. Identification of at-risk individuals and aggressive blood pressure control in the post-operative period remains the mainstay of treatment.

Carotid endarterectomy: What difference does a clinical protocol make?

BACKGROUND

The initial eight hours after carotid endarterectomy (CEA) are crucial to patient outcome as many potential complications can occur during this period. Hypotension is one of the most common issues observed after patients have returned to the surgical ward. Postoperative management of patients undergoing CEA varies between facilities, with reported direct intensive care unit or surgical high dependence unit admission. Patients that underwent a CEA procedure at the study hospital were monitored in the Recovery Unit for a minimum of four hours before being transferred to the surgical ward. Episodes of hypotension, on return to the surgical ward, were one of the main issues identified. This observation resulted in revision of the CEA management policy with collaboration from all specialties involved in the care of patients undergoing a CEA. The aim of this study was to compare whether there was any difference in short-term clinical outcomes between preupdate and postupdate of the carotid management policy in a tertiary referral hospital in New South Wales.

METHODOLOGY

Retrospective review of health care records was undertaken for the following two time intervals: prepolicy change from July 2008 to June 2009; postpolicy change from June 2011 to May 2012. Hypotension was defined as a systolic blood pressure less than 90 mm Hg. State SE 12.1 was used for data analysis.

RESULTS

After assessing for potential confounding factors-such as postoperative heart rate, risk factors, gender, and age-patients from the postpolicy change group were less likely to receive vasoactive medications to manage blood pressure deviation (OR, 0.33; 95% CI, 0.12-0.91; P = 0.026), the odds of receiving vasoactive medications was 0.33 times lower than that of the pre-policy change group patients, and is 95% confident that the true association lies between 0.12 and 0.91 in the underlying population. Over 90% of intensive care unit admission was avoided in patients from the postpolicy change group with estimated cost saving of $807 Australian dollars per patient.

CONCLUSIONS

The study hospital postoperative carotid surgery management policy has driven practice change with an extended Recovery Unit observation. This is a cost effective and safer management method. The Clinical Nurse Consultant was essential for clinical policy development, implementation, and evaluation.

Post-Carotid Endarterectomy Hypertension. Part 1: Association with Pre-operative Clinical, Imaging, and Physiological Parameters

OBJECTIVE/BACKGROUND

Post-endarterectomy hypertension (PEH) is a well recognised, but poorly understood, phenomenon after carotid endarterectomy (CEA) that is associated with post-operative intracranial haemorrhage, hyperperfusion syndrome, and cardiac complications. The aim of the current study was to identify pre-operative clinical, imaging, and physiological parameters associated with PEH.

METHODS

In total, 106 CEA patients undergoing CEA under general anaesthesia underwent pre-operative evaluation of 24 hour ambulatory arterial blood pressure (BP), baroreceptor sensitivity, cerebral autoregulation, and transcranial Doppler measurement of cerebral blood flow velocity (CBFv) and pulsatility index. Patients who met pre-existing criteria for treating PEH after CEA (systolic BP [SBP] > 170 mmHg without symptoms or SBP > 160 mmHg with headache/seizure/neurological deficit) were treated according to a previously established protocol.

RESULTS

In total, 40/106 patients (38%) required treatment for PEH at some stage following CEA (26 in theatre recovery [25%], 27 while on the vascular surgical ward [25%]), while seven (7%) had SBP surges > 200 mmHg back on the ward. Patients requiring treatment for PEH had a significantly higher pre-operative SBP (144 ± 11 mmHg vs. 135 ± 13 mmHg; p < .001) and evidence of pre-existing impairment of baroreceptor sensitivity (3.4 ± 1.7 ms/mmHg vs. 5.3 ± 2.8 ms/mmHg; p = .02). However, PEH was not associated with any other pre-operative clinical features, CBFv, or impaired cerebral haemodynamics. Paradoxically, autoregulation was better preserved in patients with PEH. All four cases of hyperperfusion associated symptoms were preceded by PEH. Length of hospital stay was significantly increased in patients with PEH (p < .001).

CONCLUSION

In this study, where all patients underwent CEA under general anaesthesia, PEH was associated with poorly controlled pre-operative BP and impaired baroreceptor sensitivity, but not with other peripheral or central haemodynamic parameters, including impaired cerebral autoregulation.

Carotid baroreceptor stimulation blood pressure response mapped in patients undergoing carotid endarterectomy (C-Map study)

OBJECTIVE

Continuous stimulation of the carotid baroreceptors has been shown to evoke a sustained systolic blood pressure (SBP) reduction in hypertensive subjects. This study conducted a detailed mapping of the SBP and heart rate response to electrical stimulus at different locations in the carotid sinus region in patients undergoing a carotid endarterectomy (CEA).

METHODS

The Carotid Sinus Autonomic Response Mapping (C-Map) Study is a multicenter, prospective, non-randomized, acute feasibility study conducted in 10 hypertensive subjects undergoing CEA. Electrode pairs were placed in multiple locations in the region of the carotid sinus for acute stimulation, and the tests were repeated after plaque removal and vessel repair.

RESULTS

The configuration that elicited the largest pressure reduction in 8 of 10 patients was with the electrodes arranged longitudinally along the medial (in relation to the bifurcation) wall of the internal carotid artery (ICA) near the bifurcation (11.2±8.1mmHg, p<0.05). There was no difference in average maximum response pre vs. post plaque removal. Spontaneous baroreflex sensitivity increased from 6.0±3.2ms/mmHg pre-CEA to 8.2±5.4ms/mmHg post-CEA (p=0.040).

CONCLUSIONS

Endarterectomy surgery did not affect maximal acute stimulation response but improved baroreflex sensitivity acutely. Acute extravascular baroreceptor stimulation (BRS) mapping demonstrated that blood pressure reductions are dependent on electrode location and orientation. In most subjects, the largest SBP reductions were elicited in the region of the medial wall of the ICA. This area can be targeted for future BRS lead design and implant.

A Prospective Nonrandomized Study on Carotid Surgery Performed under General Anesthesia without Intraoperative Cerebral Monitoring

BACKGROUND

The purpose of this study was to assess our experience of carotid surgery habitually performed under general anesthesia without intraoperative intracerebral monitoring, and following a pre-established perioperative protocol, which includes extensive use of an intraoperative shunt (IOS).

METHODS

This study included 311 consecutive carotid operations performed over 32 months. This patient cohort represents 14% of our total experience in carotid surgery (2219 operations, major stroke/mortality rate: 1.4%). The IOS was inserted routinely in the presence of intraoperative blood pressure instability during cross-clamping and when the predictable clamping time might have exceeded 20 minutes. A moderate and stable hypertension was maintained throughout surgery without IOS.

RESULTS

Overall, 120 (38.6%) endarterectomies were performed with primary closure, 73 (23.5%) with eversion technique, 113 (36.3%) with patch angioplasty, and 5 (1.6%) with other techniques. Out of 113 patch angioplasties, 111 (98.2%) were performed with an IOS. This was utilized in only 3 cases of direct carotid reconstructions or other carotid endarterectomy techniques (1.5%). Overall, the IOS placement rate was 36.7%. Postoperatively, 2 major strokes (.64%), 2 minor strokes (.64%), 4 hyperperfusion syndromes (1.3%), and no mortality were recorded. No cases of cross-clamp ischemia/shunt-related perioperative strokes were observed.

CONCLUSIONS

The low perioperative stroke rate reported in this prospective study proves the advantages of wide use of IOS during carotid surgery. This coupled with a large experience in carotid surgery and close monitoring and support of blood pressure, are the major determinants of these results that demonstrate the low risk of shunt-related complications for surgeons who regularly utilize an IOS.

Prediction of Cerebral Hyperperfusion Syndrome with Velocity Blood Pressure Index

Background:

Cerebral hyperperfusion syndrome is an important complication of carotid endarterectomy (CEA). An >100% increase in middle cerebral artery velocity (MCAV) after CEA is used to predict the cerebral hyperperfusion syndrome (CHS) development, but the accuracy is limited. The increase in blood pressure (BP) after surgery is a risk factor of CHS, but no study uses it to predict CHS. This study was to create a more precise parameter for prediction of CHS by combined the increase of MCAV and BP after CEA.

Methods:

Systolic MCAV measured by transcranial Doppler and systematic BP were recorded preoperatively; 30 min postoperatively. The new parameter velocity BP index (VBI) was calculated from the postoperative increase ratios of MCAV and BP. The prediction powers of VBI and the increase ratio of MCAV (velocity ratio [VR]) were compared for predicting CHS occurrence.

Results:

Totally, 6/185 cases suffered CHS. The best-fit cut-off point of 2.0 for VBI was identified, which had 83.3% sensitivity, 98.3% specificity, 62.5% positive predictive value and 99.4% negative predictive value for CHS development. This result is significantly better than VR (33.3%, 97.2%, 28.6% and 97.8%). The area under the curve (AUC) of receiver operating characteristic: AUC_VBI= 0.981, 95% confidence interval [CI] 0.949–0.995; AUC_VR= 0.935, 95% CI 0.890–0.966, P = 0.02.

Conclusions:

The new parameter VBI can more accurately predict patients at risk of CHS after CEA. This observation needs to be validated by larger studies.

Hemodynamic changes and baroreflex sensitivity associated with carotid endarterectomy and carotid artery stenting

Atherosclerotic carotid lesion is a major cause of stroke which accounts for up to 20% of ischemic stroke. Aggressive treatment of carotid stenosis may prevent stroke. Currently, carotid endarterectomy (CEA) and carotid artery stenting (CAS) are the first-line treatments for severe carotid stenosis. CEA is superior to medical therapy in preventing stroke and cardiovascular death. CAS has emerged as an alternative to CEA in recent years due to its less invasive nature. However, both CEA and CAS may be associated with adverse hemodynamic changes as well as a variation of carotid baroreflex sensitivity. There is no consensus on which of these two methods is more advantageous concerning the procedure-related hemodynamic changes. This article reviews the hemodynamic changes and baroreflex sensitivity after CEA and CAS.