Local versus general anaesthesia for carotid endarterectomy

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.

Intraoperative Cerebral Monitoring During Carotid Surgery: A Narrative Review

BACKGROUND

Intra-operative neurological monitoring (IONM) during carotid endarterectomy (CEA) aims to reduce neurological morbidity of surgery.

OBJECTIVE

This narrative review analyses the role and results of different methods of IONM.

METHODS

review articles on PUBMED and Cochrane Library, by searching key words related to IONM and CEA, from 2000 up to date.

RESULTS

regional anesthesia in some centers represents the "gold standard". The most often used alternative techniques are: stump pressure, electroencephalogram, somatosensory evoked potentials, transcranical doppler ultrasound, near infrared spectroscopy and routine shunting. Every technique shows limitations. Regional anesthesia can make difficult prompt intubation when needed. Stump pressure shows a wide operative range. Electroencephalogram is unable to detect ischemia in sub-cortical regions of the brain. Somatosensory evoked potentials certainly demonstrate the presence of cerebral ischemia, but are no more specific or sensitive than the electroencephalogram. Transcranical doppler monitoring is undoubtedly operator-dependent and suffers from the limitations that the probe has to be placed relatively near to the surgical site and may impede the operator, especially if it needs constant adjustments; moreover, an acoustic window may not be found in 10% -20% of the subjects. Near infrared spectroscopy appears to have a high negative predictive value for cerebral ischemia, but has a poor positive predictive value and low specificity, because predominantly estimates venous oxygenation as this makes up about 80% of cerebral blood volume. The data on the use of Routine Shunting (RS) from RCTs are limited.

CONCLUSIONS

currently, with no clear consensus on monitoring technique, choice should be guided by local expertise and complication rates. With reflection, best practice may dictate that a standard technique is selected as suggested above and this remains the default position for individual practice. Nevertheless, current techniques for monitoring cerebral perfusion during CEA are associated with false negative and false positive resulting in inappropriate shunt insertion.

Outcomes of Carotid Endarterectomy according to the Anesthetic Method: General versus Regional Anesthesia

Background

The surgical strategies for carotid endarterectomy (CEA) vary in terms of the anesthesia method, neurological monitoring, shunt usage, and closure technique, and no gold-standard procedure has been established yet. We aimed to analyze the feasibility and benefits of CEA under regional anesthesia (RA) and CEA under general anesthesia (GA).

Methods

Between June 2012 and December 2017, 65 patients who had undergone CEA were enrolled, and their medical records were prospectively collected and retrospectively reviewed. A total of 35 patients underwent CEA under RA with cervical plexus block, whereas 30 patients underwent CEA under GA. In the RA group, a carotid shunt was selectively used for patients who exhibited negative results on the awake test. In contrast, such a shunt was used for all patients in the GA group.

Results

There were no cases of postoperative stroke, cardiovascular events, or mortality. Nerve injuries were noted in 4 patients (3 in the RA group and 1 in the GA group), but they fully recovered prior to discharge. Operative time and clamp time were shorter in the RA group than in the GA group (119.29±27.71 min vs. 161.43±20.79 min, p<0.001; 30.57±6.80 min vs. 51.77±13.38 min, p<0.001, respectively). The hospital stay was shorter in the RA group than in the GA group (14.6±5.05 days vs. 18.97±8.92 days, p=0.022). None of the patients experienced a stroke or restenosis during the 27.23±20.3-month follow-up period.

Conclusion

RA with a reliable awake test reduces shunt use and decreases the clamp and operative times of CEA, eventually resulting in a reduced length of hospital stay.

General Anesthesia Versus Local Anesthesia in Carotid Endarterectomy: A Systematic Review and Meta-Analysis

OBJECTIVE

The choice of anesthetic technique in carotid endarterectomy (CEA) has been controversial. This study compared the outcomes of general anesthesia (GA) and local anesthesia (LA) in CEA.

DESIGN

Systematic review and meta-analysis of comparative studies.

SETTING

Hospitals.

PARTICIPANTS

Adult patients undergoing CEA with either LA or GA.

INTERVENTIONS

The effects of GA and LA on CEA outcomes were compared.

MEASUREMENTS AND MAIN RESULTS

PubMed, OVID, Scopus, and Embase were searched to June 2018. Thirty-one studies with 152,376 patients were analyzed. A random effect model was used, and heterogeneity was assessed with the I² and chi-square tests. LA was associated with shorter surgical time (weighted mean difference -9.15 min [-15.55 to -2.75]; p = 0.005) and less stroke (odds ratio [OR] 0.76 [0.62-0.92]; p = 0.006), cardiac complications (OR 0.59 [0.47-0.73]; p < 0.00001), and in-hospital mortality (OR 0.72 [0.59-0.90]; p = 0.003). Transient neurologic deficit rates were similar (OR 0.69 [0.46-1.04]; p = 0.07). Heterogeneity was significant for surgical time (I² = 0.99, chi-square = 1,336.04; p < 0.00001), transient neurologic deficit (I² = 0.41, chi-square = 28.81; p = 0.04), and cardiac complications (I² = 0.42, chi-square = 43.32; p = 0.01) but not for stroke (I² = 0.22, chi-square = 30.72; p = 0.16) and mortality (I² = 0.00, chi-square = 21.69; p = 0.65). Randomized controlled trial subgroup analysis was performed, and all the aforementioned variables were not significantly different or heterogenous.

CONCLUSION

The results from this study showed no inferiority of using LA to GA in patients undergoing CEA. Future investigations should be reported more systematically, preferably with randomization or propensity-matched analysis, and thus registries will facilitate investigation of this subject. Anesthetic choice in CEA should be individualized and encouraged where applicable.

Case Series about the Changed Antiplatelet Protocol for Carotid Endarterectomy in a Teaching Hospital: More Patients with Complications?

Introduction  In the Netherlands, clopidogrel monotherapy increasingly replaces acetylsalicylic acid and extended release dipyridamole as the first-choice antiplatelet therapy after ischemic stroke. It is unknown whether the risk of peri- and postoperative hemorrhage in carotid artery surgery is higher in patients using clopidogrel monotherapy compared with acetylsalicylic acid and extended release dipyridamole. We therefore retrospectively compared occurrence of perioperative major and (clinical relevant) minor bleedings during and after carotid endarterectomy of two groups using different types of platelet aggregation inhibition after changing our daily practice protocol in our center.

Material and Methods  A consecutive series of the most recent 80 carotid endarterectomy patients (November 2015–August 2017) treated with the new regime (clopidogrel monotherapy) were compared with the last 80 (January 2012–November 2015) consecutive patients treated according to the old protocol (acetylsalicylic acid and dipyridamole). The primary endpoint was any major bleeding during surgery or in the first 24 to 72 hours postoperatively. Secondary outcomes within 30 days after surgery included minor (re)bleeding postoperative stroke with persistent or transient neurological deficit, persisting or transient neuropraxia, asymptomatic restenosis or occlusion, (transient) headache. Reporting of this study is in line with the ‘Strengthening the Reporting of Observational Studies in Epidemiology’ statement.

Results  Although statistical differences were observed, from a clinical perspective both patients groups were comparable. Postoperative hemorrhage requiring reexploration for hemostasis occurred in none of the 80 patients in the group of the clopidogrel monotherapy (new protocol) and it occurred in one of the 80 patients (1%) who was using acetylsalicylic acid and dipyridamole (old protocol). In three patients (4%) in the clopidogrel monotherapy and one patient (1%) in the acetylsalicylic acid and extended release dipyridamole protocol an ipsilateral stroke was diagnosed.

Conclusion  In this retrospective consecutive series the incidence of postoperative ischemic complications and perioperative hemorrhage after carotid endarterectomy (CEA) seemed to be comparable in patients using clopidogrel monotherapy versus acetylsalicylic acid and extended release dipyridamole for secondary prevention after a cerebrovascular event. This study fuels the hypothesis that short- and midterm complications of clopidogrel and the combination acetylsalicylic acid and extended release dipyridamole are comparable.

Lactate/pyruvate monitoring during carotid endarterectomy under general anaesthesia versus cervical plexus block: A randomised controlled study

BACKGROUND AND AIMS

Carotid endarterectomy (CEA) reduces the risk of stroke in patients with significant carotid stenosis and may be performed under general anaesthesia (GA) or regional anaesthesia (RA). This study aimed to compare RA and GA with regard the jugular venous bulb blood lactate and pyruvate levels.

METHODS

This randomised-controlled trial was done between October-2013 and September-2015. Thirty-six patients were randomised into either GA or RA groups, with six excluded after randomisation. In the RA group, combined deep and superficial cervical plexus blocks were performed. In the GA group, anaesthesia was induced with propofol and fentanyl. In both groups, monitoring of neurological function was done. Sampling of the contralateral jugular bulb blood was done. The main outcome measures were lactate and pyruvate in the jugular venous blood. For comparing categorical data, Chi-square test was used, and for the numerical variables, t-test was used.

RESULTS

Demographics were comparable in the two Groups. Serum lactate and pyruvate levels were higher in the GA group than RA group. At 120 min under anaesthesia, lactate and pyruvate levels under RA vs. GA, respectively were 0.76±0.03 mEq/L vs. 1.14±0.06, p-0.001 mEq/L, and 0.08± 0.00 mEq/L vs. 0.10±0.01 mEq/L, p=0.006. Lactate/ pyruvate ratios were normal in both groups. The mean blood pressure was significantly lower in the GA group during anaesthesia.

CONCLUSION

In patients undergoing Carotid endarterectomy, serum levels of both lactate and pyruvate were higher under general versus regional anaesthesia.

Perioperative time course of matrix metalloproteinase-9 (MMP-9), its tissue inhibitor TIMP-1 & S100B protein in carotid surgery

Background & objectives:

Ischaemic stroke is a life burdening disease for which carotid endarterectomy (CEA) is considered a gold standard intervention. Pro-inflammatory markers like matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) and S-100 Beta (S100B) may have a role in the early inflammation and cognitive decline following CEA. This study was aimed to describe the perioperative time courses and correlations between of MMP-9, TIMP-1 and S100B following CEA.

Methods:

Fifty four patients scheduled for CEA were enrolled. Blood samples were collected at four time points, T₁: preoperative, T₂: 60 min after cross-clamp release, T₃: first postoperative morning, T₄: third postoperative morning. Twenty atherosclerotic patients were included as controls. Plasma MMP-9, TIMP-1 and S100B levels were estimated by ELISA.

Results:

TIMP-1 was decreased significantly in the CEA group (P<0.01). Plasma MMP-9 was elevated and remained elevated from T_1-4 in the CEA group (P<0.05) with a marked elevation in T₃ compared to T₁ (P<0.05). MMP-9/TIMP-1 was elevated in the CEA group and increased further by T₂ and T₃ (P<0.05). S100B was elevated on T₂ and decreased on T_3-4 compared to T₁.

Interpretation & conclusions:

Our study provides information on the dynamic changes of MMP-9-TIMP-1 system and S100B in the perioperative period. Preoperative reduction of TIMP-1 might be predictive for shunt requirement but future studies are required for verification.

Benefits of using dexmedetomidine during carotid endarterectomy: A review

As per current recommendation, patients with acute ischemic stroke should be offered carotid endarterectomy (CEA) within 24-72 hours. The same applies to patients with recurrent transient ischemic attacks (TIA). This time is usually less for hemodynamic optimization of patients who’ve suffered acute ischemic stroke. Hence’ they are hemodynamically labile and can have accelerated hypertension on induction/extubation. This can have disastrous outcomes. It is a common practice among anesthesiologists to avoid angiotensin converting enzyme(ACE) inhibitors or angiotensin receptor blockers on the day of surgery. This also adds to hypertensive issues perioperatively. Dexmedetomidine is a wonderful drug which can be used during CEA. Due to its centrally mediated sympatholytic effect, it confers good hemodynamic control during induction, intraoperatively, and during extubation. We did a search on PubMed and Google for carotid endarterectomies done under general and locoregional anesthesia during which dexmedetomidine was used. The keywords used by us during the search were as follows: anesthesia, carotid endarterectomy, anesthesia. We also searched for use of dexmedetomidine infusion to attenuate hypertensive response to intubation and for providing stability in major surgeries like CABG, craniotomies, bariatric surgeries, and valve replacements.

Effectiveness of preoperative beta-blockade on intra-operative heart rate in vascular surgery cases conducted under regional or local anesthesia

BACKGROUND

Preoperative β-blockade has been posited to result in better outcomes for vascular surgery patients by attenuating acute hemodynamic changes associated with stress. However, the incremental effectiveness, if any, of β-blocker usage in blunting heart rate responsiveness for vascular surgery patients who avoid general anesthesia remains unknown.

METHODS

We reviewed an existing database and identified 213 consecutive vascular surgery cases from 2005-2011 conducted without general anesthesia (i.e., under monitored anesthesia care or regional anesthesia) at a tertiary care Veterans Administration medical center and categorized patients based on presence or absence of preoperative β-blocker prescription. For this series of patients, with the primary outcome of maximum heart rate during the interval between operating room entry to surgical incision, we examined the association of maximal heart rate and preoperative β-blocker usage by performing crude and multivariate linear regression, adjusting for relevant patient factors.

RESULTS

Of 213 eligible cases, 137 were prescribed preoperative β-blockers, and 76 were not. The two groups were comparable across baseline patient factors and intraoperative medication doses. The β-blocker group experienced lower maximal heart rates during the period of evaluation compared to the non-β-blocker group (85 ± 22 bpm vs. 98 ± 36 bpm, respectively; p = 0.002). Adjusted linear regression confirmed a statistically-significant association between lower maximal heart rate and the use of β-blockers (Beta = -11.5; 95% CI [-3.7, -19.3] p = 0.004).

CONCLUSIONS

The addition of preoperative β-blockers, even when general anesthesia is avoided, may be beneficial in further attenuating stress-induced hemodynamic changes for vascular surgery patients.

Regional anaesthesia techniques for carotid surgery: the state of art

PURPOSE

This review will analyse some aspects of regional anaesthesia (RA) for carotid endarterectomy (CEA), a surgical procedure which requires a strict monitoring of patient's status. RA remains an important tool for the anaesthesiologist. Some debates remain about type and definition of regional anaesthesia, efficacy and safety of the different cervical block techniques, the right dose, concentration and volume of local anaesthetic, the use of adjuvants, the new perspectives: ultrasonography, the future directions.

METHODS

A literature search was performed for journal articles in English language in the PubMed Embase and in The Cochrane Library database, from January 2000 to December 2013. The electronic search strategy contained the following medical subject headings and free text terms: local anaesthesia versus general anaesthesia for endarterectomy, superficial and deep cervical block, complications of cervical nerve block, ultrasound guidance of superficial and deep cervical plexus block.

CONCLUSIONS

The gold standard for RA will be achieved after overcoming a number of limitations by a more extensive use of ultrasonography, by combining general and regional anaesthesia, including conscious anaesthesia, by defining the appropriate volume, concentration and dosage of local agents and by addition of adjuvants.

Surgery Versus Stenting in Symptomatic Patients

Symptomatic carotid artery stenosis is an important cause of stroke with significant morbidity and mortality. Revascularization with carotid endarterectomy reduces the recurrence of stroke and until recently was considered the gold standard of therapy. Carotid artery stenting has emerged as an alternative method of revascularization in both high-risk and standard-risk patients. This review appraises the role of surgery versus stenting for patients with symptomatic carotid stenosis.

Anesthetic technique and acute kidney injury in endovascular abdominal aortic aneurysm repair

OBJECTIVE

Prior studies suggest that general anesthesia (GA) is associated with worse cardiopulmonary outcomes after endovascular abdominal aortic aneurysm repair (EVAR). Patients undergoing EVAR are at a high risk of developing perioperative acute kidney injury (AKI), and the relationship between anesthetic technique and AKI in these patients is not well-characterized. The authors sought to determine if anesthetic technique affected the risk of AKI in patients undergoing EVAR.

DESIGN

Retrospective, observational cohort study analyzed using a multivariate logistic regression model to assess the effects of anesthetic technique on renal outcome.

SETTING

Multiple institutions, mainly in North America.

PARTICIPANTS

Patients in the American College of Surgeons National Surgical Quality Improvement Program from 2005-2010 undergoing EVAR.

INTERVENTIONS

The authors investigated the association between anesthetic techniques, comparing GA to alternative (non-GA) techniques, and AKI.

MEASUREMENTS AND MAIN RESULTS

AKI was defined as an increase in the creatinine level of>2 mg/dL and/or dialysis. Of 13,026 patients, 84.4% underwent GA and 15.6% underwent non-GA techniques. AKI developed in 2.0% of the GA group and 1.4% of the non-GA group (unadjusted odds ratio [OR] 1.43, p = 0.075; adjusted OR [aOR] 1.00, p = 0.99). Risk factors for AKI include ASA class, ruptured aneurysm, preoperative renal dysfunction, symptomatic cardiovascular disease, and perioperative blood transfusion.

CONCLUSIONS

Anesthetic technique is not independently associated with the risk of AKI in patients undergoing EVAR.

The need for treatment of hemodynamic instability following carotid endarterectomy is associated with increased perioperative and 1-year morbidity and mortality

OBJECTIVE

The objective of this study was to evaluate the outcomes of patients after carotid endarterectomy (CEA) who developed postoperative hypertension or hypotension requiring the administration of intravenous vasoactive medication (IVMED).

METHODS

We examined consecutive, primary elective CEA performed by 128 surgeons within the Vascular Study Group of New England (VSGNE) database (2003-2010) and compared outcomes of patients who required postoperative IVMED to treat hyper- or hypotension with those who did not. Outcomes included perioperative death, stroke, myocardial infarction (MI), congestive heart failure (CHF), hospital length of stay, and 1-year stroke or death. Propensity score matching was performed to facilitate risk-adjusted comparisons. Multivariable regression models were used to compare the association between IVMED and outcomes in unmatched and matched samples. Factors associated with use of IVMED in postoperative hypertension and hypotension were evaluated, and predictive performance of multivariable models was examined using receiver operating characteristic (ROC) curves.

RESULTS

Of 7677 elective CEAs identified, 23% received IVMED for treatment of either postoperative hypertension (11%) or hypotension (12%). Preoperative neurological symptomatic status (20%) was similar across cohorts. In the crude sample, the use of IVMED to treat postoperative hypertension was associated with increased 30-day mortality (0.7% vs 0.1%; P < .001), stroke (1.9% vs 1%; P = .018), MI (2.4% vs 0.5%; P < .001), and CHF (1.9% vs 0.5%; P < .001). The use of IVMED to treat postoperative hypotension was also associated with increased perioperative mortality (0.8% vs 0.1%; P < .001), stroke (3.2% vs 1.0%; P < .001), MI (2.7% vs 0.5%; P < .001), and CHF (1.7% vs 0.5%; P < .001), as well as 1-year death (5.1% vs 2.9%; P < .001) or stroke (4.2% vs 2.1%; P < .001). Hospital length of stay was significantly longer among patients who needed IVMED for postoperative hypertension (2.8 ± 4.7 days vs 1.7 ± 5.5 days; P < .001) and hypotension (2.8 ± 5.9 days vs 1.7 ± 5.5 days; P < .001). In multivariable analysis, IVMED for postoperative hypertension was associated with increased MI, stroke, or death (odds ratio, 2.6; 95% confidence interval [CI], 1.6-4.1; P < .001). Similarly, IVMED for postoperative hypotension was associated with increased MI, stroke, or death (odds ratio, 3.2; 95% CI, 2.1-5.0; P < .001), as well as increased 1-year stroke or death (hazard ratio, 1.6; 95% CI, 1.2-2.2; P = .003). Smoking, coronary artery disease, and clopidogrel (ROC, 0.59) were associated with postoperative hypertension requiring IVMED, whereas conventional endarterectomy and general anesthesia were associated with postoperative hypotension requiring IVMED (ROC, 0.58). The unitization of IVMED varied between 11% and 38% across VSGNE, and center effect did not affect outcomes.

CONCLUSIONS

Postoperative hypertension requiring IVMED after CEA is associated with increased perioperative mortality, stroke, and cardiac complications, whereas significant postoperative hypotension is associated with increased perioperative mortality, cardiac, or stroke complications, as well as increased 1-year death or stroke following CEA. The utilization of IVMED varied across centers and, as such, further investigation into this practice needs to occur in order to improve outcomes of these at-risk patients.

Research studies that have influenced practice of neuroanesthesiology in recent years: A literature review

Through evolving research, recent years have witnessed remarkable achievements in neuromonitoring and neuroanesthetic techniques, with a huge body of literature consisting of excellent studies in neuroanaesthesiology. However, little of this work appears to be directly important to clinical practice. Many controversies still exist in care of patients with neurologic injury. This review discusses studies of great clinical importance carried out in the last five years, which have the potential of influencing our current clinical practice and also attempts to define areas in need of further research. Relevant literature was obtained through multiple sources that included professional websites, medical journals and textbooks using key words “neuroanaesthesiology,” “traumatic brain injury,” “aneurysmal subarachnoid haemorrhage,” “carotid artery disease,” “brain protection,” “glycemic management” and “neurocritical care.” In head injured patients, administration of colloid and pre-hospital hypertonic saline resuscitation have not been found beneficial while use of multimodality monitoring, individualized optimal cerebral perfusion pressure therapy, tranexamic acid and decompressive craniectomy needs further evaluation. Studies are underway for establishing cerebroprotective potential of therapeutic hypothermia. Local anaesthesia provides better neurocognitive outcome in patients undergoing carotid endarterectomy compared with general anaesthesia. In patients with aneurysmal subarachnoid haemorrhage, induced hypertension alone is currently recommended for treating suspected cerebral vasospasm in place of triple H therapy. Till date, nimodipine is the only drug with proven efficacy in preventing cerebral vasospasm. In neurocritically ill patients, intensive insulin therapy results in substantial increase in hypoglycemic episodes and mortality rate, with current emphasis on minimizing glucose variability. Results of ongoing multicentric trials are likely to further improvise our practice.

The diagnosis, treatment and follow-up of extracranial carotid stenosis

BACKGROUND

Extracranial atherosclerotic lesions of the carotid bifurcation cause 10% to 20% of all cases of cerebral ischemia. Until now, there have been no comprehensive evidence- and consensus-based recommendations for the management of patients with extracranial carotid stenosis in Germany and Austria.

METHODS

The literature was systematically searched for pertinent publications (1990-2011). On the basis of 182 randomized clinical trials (RCTs) and 308 systematic reviews, 30 key questions were answered and evidence-based recommendations were issued.

RESULTS

The prevalence of extracranial carotid stenosis is more than 5% from age 65 onward. Men are affected twice as frequently as women. The most important diagnostic technique is Doppler- and color-coded duplex ultrasonography. RCTs have shown that the treatment of high-grade asymptomatic carotid stenosis with carotid endarterectomy (CEA) can lower the 5-year risk of stroke from 11% to 5%. Intensive conservative treatment may lower the stroke risk still further. Moreover, RCTs have shown that CEA for symptomatic 50% to 99% carotid stenosis lowers the 5-year stroke risk by 5% to 16%. Meta-analyses of the 13 available RCTs comparing carotid artery stenting (CAS) with CEA have shown that CAS is associated with a 2% to 2.5% higher risk of periprocedural stroke or death and with a 0.5% to 1% lower risk of periprocedural myocardial infarction. If no particular surgical risk factors are present, CEA is the standard treatment for high-grade carotid stenosis. CAS may be considered as an alternative to CEA if the rate of procedure-related stroke or death can be kept below 3% or 6% for asymptomatic and symptomatic stenosis, respectively.

CONCLUSION

Further studies are needed so that better selection criteria can be developed for individually tailored treatment.

Regional anesthesia for vascular surgery

Vascular surgical patients are a diverse group of patients who tend to be elderly, with multiple comorbidities, while vascular procedures may involve significant blood loss and ischemia of tissues beyond the arterial obstruction. Regional anesthesia techniques may offer benefits to patients undergoing vascular surgery because of their cardiorespiratory comorbidities. However, this group of patients is commonly receiving multiple medications, including anticoagulants, so regional techniques are not without risks. This review will discuss this topic based around 3 fundamental revascularization procedures, carotid, abdominal aortic aneurysm repair, and infrainguinal surgery, discussing the clinical applications of regional techniques relevant to each key area.

Prevention of Intra-operative Cerebral Ischemia during Carotid Endarterectomy, Loco-regional versus General Anesthesia

Carotid endarterectomy (CEA), as a prophylactic operation is becoming more popular. It is performed in patients who are at risk of stroke from dislodged atheromatous plaque at the carotid bifurcation. The major concern during CEA is the detection of cerebral hypoperfusion or ischemia during carotid cross clamping. Some studies have shown that the introduction of loco-regional anesthesia has lowered the incidence of major complications compared with general anesthesia since ischemia detection is easier in conscious patient.

Restenosis after microsurgical non-patch carotid endarterectomy in 586 patients

Background

Carotid endarterectomy (CEA) reduces the risk of stroke in patients with symptomatic (>50%) and asymptomatic (>60%) carotid artery stenosis. Here we report the midterm results of a microsurgical non-patch technique and compare these findings to those in the literature.

Methods

From 1998 to 2009 we treated 586 consecutive patients with CEA. CEA was performed, under general anesthesia, with a surgical microscope using a non-patch technique. Somatosensory evoked potential and transcranial Doppler were continuously monitored. Cross-clamping was performed under EEG burst suppression and adaptive blood pressure increase. Follow-up was performed by an independent neurologist. Mortality at 30 days and morbidity such as major and minor stroke, peripheral nerve palsy, hematoma and cardiac complications were recorded. The restenosis rate was assessed using duplex sonography 1 year after surgery.

Results

A total of 439 (75%) patients had symptomatic and 147 (25%) asymptomatic stenosis; 49.7% of the stenoses were on the right-side. Major perioperative strokes occurred in five (0.9%) patients [n = 4 (0.9%) symptomatic; n = 1 (0.7%) asymptomatic patients]. Minor stroke was recorded in six (1%) patients [n = 4 (0.9%) symptomatic; n = 2 (1.3%) asymptomatic patients]. Two patients with symptomatic stenoses died within 1 month after surgery. Nine patients (1.5%) had reversible peripheral nerve palsies, and nine patients (1.5%) suffered a perioperative myocardial infarction. High-grade (>70%) restenosis at 1 year was observed in 19 (3.2%) patients [n = 12 (2.7%) symptomatic; n = 7 (4.7%) asymptomatic patients].

Conclusions

The midterm rate of restenosis was low when using a microscope-assisted non-patch endarterectomy technique. The 30-day morbidity and mortality rate was comparable or lower than those in recently published surgical series.

Prolonged Dyspnea after Interscalene Block: Attributed to Undiagnosed Addison's Disease and Myasthenia Gravis

This report describes a patient who had a series of daily interscalene nerve blocks to treat pain following a shoulder manipulation for postsurgical stiffness. She experienced acute respiratory compromise that persisted for many weeks. All typical and unusual causes of these symptoms were ruled out. Her treating pulmonologist theorized that the ipsilateral carotid body had been injured. However, it was subsequently determined that the constellation of symptoms and their prolonged duration were best explained by a poor stress response from Addison's disease coupled with exacerbation of early onset myasthenia gravis. This patient's case is not a typical reaction to interscalene nerve blocks, and thus preoperative testing would not be recommended for myasthenia gravis or Addison's disease without underlying suspicion. We describe this report to inform physicians to consider a workup for these diagnoses if a typical workup rules out all usual causes of complications from an interscalene block.

[Anesthesia for carotid endarterectomy: a review]

Cardiovascular diseases are associated with high rates of morbidity and mortality. Carotid artery stenosis causes between 20% and 25% of ischemic strokes, especially when an embolism is the underlying cause. Carotid endarterectomy is the treatment of choice when stenosis exceeds 60%. It is important to have an understanding of how to manage perioperative factors that can decrease the risk of stroke, infarction, and death. In contrast to the findings of earlier meta-analyses, the recent GALA trial of general versus local anesthesia concluded that the rates of stroke, myocardial infarction, and mortality during or soon after surgery are similar for both types of anesthesia.

Local versus general anaesthesia for carotid endarterectomy

BACKGROUND

Carotid endarterectomy reduces the risk of stroke in people with recently symptomatic, severe carotid artery stenosis. However, there are significant perioperative risks which may be lessened by performing the operation under local rather than general anaesthetic. This is an update of a Cochrane review first published in 1996, and previously updated in 2004.

OBJECTIVES

To assess the risks of endarterectomy under local compared with general anaesthetic.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched December 2007), MEDLINE (1966 to April 2007) EMBASE (1980 to April 2007) and Index to Scientific and Technical Proceedings (ISTP, 1980 to April 2007). We also handsearched six relevant journals to April 2007, and searched the reference lists of articles identified. For the previous version of this review we handsearched a further seven journals to 2002 and in August 2001 advertised the review in Vascular News, a newspaper for European vascular specialists.

SELECTION CRITERIA

Randomised trials and non-randomised studies comparing carotid endarterectomy under local versus general anaesthetic.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial quality and extracted the data independently.

MAIN RESULTS

Nine randomised trials involving 812 operations, and 47 non-randomised studies involving 24,181 operations were included. Meta-analysis of the randomised studies showed that there was no evidence of a reduction in the odds of operative stroke, but the use of local anaesthetic was associated with a significant reduction in local haemorrhage (odds ratio 0.30, 95% confidence interval 0.12 to 0.77) within 30 days of the operation. However, the randomised trials were too small to allow reliable conclusions to be drawn, and in some studies intention-to-treat analyses were not possible because of exclusions. Meta-analsis of the non-randomised studies showed that the use of local anaesthetic was associated with significant reductions in the odds of stroke (38 studies), death (42 studies), stroke or death (27 studies), myocardial infarction (27 studies), and pulmonary complications (seven studies), within 30 days of the operation. The methodological quality of the non-randomised trials was questionable. Thirteen of the non-randomised studies were prospective and 36 reported on a consecutive series of patients. In eleven non-randomised studies the number of arteries, as opposed to the number of patients, was unclear.

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomised trials comparing carotid endarterectomy performed under local and general anaesthetic. Non-randomised studies suggest potential benefits with the use of local anaesthetic, but these studies may be biased.