Shunt intention during carotid endarterectomy in the early symptomatic period and perioperative stroke risk

Current Practices in Carotid Surgery

We outline the indications and contraindications of carotid endarterectomy (CEA) and appraise four key areas still debated to this day; shunting versus non-shunting, patch angioplasty (PA) versus primary closure (PC) and local anaesthesia (LA) versus general anaesthesia (GA). Importantly, we compare CEA with Best Medical Therapy (BMT), which is an area that is still largely debated, principally because many of the studies conducted to date do not reflect the era of modern BMT practices, and these outcomes are eagerly awaited. Literature searches were conducted using Pubmed with the keywords 'carotid', and 'endarterectomy', which provided a wide variety of journals and articles. We further stratified our data by using only randomised control trials (RCTs), meta-analyses, and systematic reviews, and then excluded studies with asymptomatic disease, diabetes, and plaque-imaging studies, including studies that did not fit our four desired topics for discussion. For each of the different domain's, results demonstrated similar peri-operative outcomes when comparing shunting vs. non-shunting and modality of anaesthesia and therefore practice still remains dependent on operator experience and preference. Patch-angioplasty reduces the risk of subsequent stroke, transient ischaemic attack (TIA), and re-stenosis compared to PC. In carotid stenosis >50% BMT offers limited benefits without accompanying surgical intervention and BMT alone tends to be advantageous primarily for patients with <50% carotid stenosis. Where CEA is appraised in terms of superiority of the procedural components; the literature does not support wildly contrasting outcomes to change majority practice. However, the area of considerable interest is superiority of BMT to surgical intervention in terms of both carotid artery stenting (CAS) and CEA and more studies need to be conducted in this area.

Safety of Shunting Strategies During Carotid Endarterectomy: A Vascular Quality Initiative Data Analysis

OBJECTIVE

This study aimed to evaluate in hospital outcomes after carotid endarterectomy (CEA) according to shunt usage, particularly in patients with contralateral carotid occlusion (CCO) or recent stroke. Data from CEAs registered in the Vascular Quality Initiative database between 2012 and 2020 were analysed, excluding surgeons with < 10 CEAs registered in the database, concomitant procedures, re-interventions, and incomplete data.

METHODS

Based on their rate of shunt use, participating surgeons were divided in three groups: non-shunters (< 5%), selective shunters (5 - 95%), and routine shunters (> 95%). Primary outcomes of in hospital stroke, death, and stroke and death rate (SDR) were analysed in symptomatic and asymptomatic patients.

RESULTS

A total of 113 202 patients met the study criteria, of whom 31 147 were symptomatic and 82 055 were asymptomatic. Of the 1 645 surgeons included, 12.1% were non-shunters, 63.6% were selective shunters, and 24.3% were routine shunters, with 10 557, 71 160, and 31 579 procedures in each group, respectively. In the univariable analysis, in hospital stroke (2.0% vs. 1.9% vs. 1.6%; p = .17), death (0.5% vs. 0.4% vs. 0.4%; p = .71), and SDR (2.2% vs. 2.1% vs. 1.8%; p = .23) were not statistically significantly different among the three groups in the symptomatic cohort. The asymptomatic cohort also did not show a statistically significant difference for in hospital stroke (0.9% vs. 1.0% vs. 0.9%; p = .55), death (0.2% vs. 0.2% vs. 0.2%; p = .64), and SDR (1.0% vs. 1.1% vs. 1.0%; p = .43). The multivariable model did not show a statistically significant difference for the primary outcomes between the three shunting cohorts. On subgroup analysis, the SDRs were not statistically significantly different for patients with CCO (3.3% vs. 2.5% vs. 2.4%; p = .64) and those presenting with a recent stroke (2.9% vs. 3.4% vs. 3.1%; p = .60).

CONCLUSION

No statistically significant differences were found between three shunting strategies for in hospital SDR, including in patients with CCO or recent stroke.

Brazilian Angiology and Vascular Surgery Society Guidelines for the treatment of extracranial cerebrovascular disease

Extracranial cerebrovascular disease has been the subject of intense research throughout the world, and is of paramount importance for vascular surgeons. This guideline, written by the Brazilian Society of Angiology and Vascular Surgery (SBACV), supersedes the 2015 guideline. Non-atherosclerotic carotid artery diseases were not included in this document. The purpose of this guideline is to bring together the most robust evidence in this area in order to help specialists in the treatment decision-making process. The AGREE II methodology and the European Society of Cardiology system were used for recommendations and levels of evidence. The recommendations were graded from I to III, and levels of evidence were classified as A, B, or C. This guideline is divided into 11 chapters dealing with the various aspects of extracranial cerebrovascular disease: diagnosis, treatments and complications, based on up-to-date knowledge and the recommendations proposed by SBACV.

Interventions in Carotid Artery Surgery: An Overview of Current Management and Future Implications

Atherosclerotic carotid artery disease has been well studied over the last half-century by multiple randomized controlled trials attempting to elucidate the appropriate modality of therapy for this disease process. Surgical techniques have evolved from carotid artery endarterectomy and transfemoral carotid artery stenting to the development of hybrid techniques in transcarotid artery revascularization. In this article, the authors provide a review of the available literature regarding operative and medical management of carotid artery disease.

Update in Carotid Disease

This review of the literature analyzes publications over the past five years on various problems associated with carotid endarterectomy: 1. Is the eversion or classical technique of surgery with plastic repair of the reconstruction area with a patch more effective? 2. Carotid endarterectomy or carotid angioplasty with stenting is more optimal? 3. When should brain revascularization be performed after the development of ischemic stroke? 4. Should a temporary shunt be used to protect the brain during carotid endarterectomy? 5. How to prevent and treat different types of intraoperative ischemic strokes? 6. What tactics of treatment of patients with combined lesions of the carotid and coronary arteries is more effective? 7. What are the causes and methods of elimination of restenosis of the internal carotid artery known? 8. Is carotid endarterectomy safe in old age?

A systematic review & meta-analysis on perioperative cerebral and hemodynamic monitoring methods during carotid endarterectomy

OBJECTIVE

To compare outcomes between different strategies of perioperative cerebral and hemodynamic monitoring during carotid endarterectomy.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, and Cochrane CENTRAL databases were searched.

METHODS

This review was performed according to the PRISMA guidelines and prospectively registered in the international prospective register of systematic reviews (CRD42021241891). The GRADE approach was used to describe the methodological quality of the studies and certainty of the evidence. The primary outcome was 30-day stroke rate. Secondary outcomes measures are 30-day ipsilateral stroke, 30-day mortality, shunt rate and complication rates.

RESULTS

The search identified 3 460 articles. Seventeen RCTs, three prospective observational studies and seven registries were included, reporting on 236 983 patients. The overall pooled 30-day stroke rate is 1.8% (95% CI 1.4 - 2.2%), ranging from 0 - 12.6%. In RCT's the pooled 30-day stroke rate is 2.7% (95% CI 1.6 - 3.7%) compared to 1.3% (95%CI 0.8 - 1.8%) in the registries. The overall stroke risk decreased from 3.7% before the year 2000 to 1.6% after 2000. No significant differences could be identified between different monitoring and shunting strategies, although a trend to higher stroke rates in routine no shunting arms of RCTs was observed. Overall 30-day mortality, myocardial infarction and nerve injury rates are 0.6% (95%CI 0.4 - 0.8), 0.8% (95%CI 0.6-1.0) and 1.3% (95%CI 0.4-2.2), respectively.

CONCLUSIONS

No significant differences between the compared shunting and monitoring strategies are found. However, routine no shunting is not recommended. The available data is too limited to prefer one method of neuromonitoring over another method when selective shunting is applied.

Outcomes and role of shunting during carotid endarterectomy for symptomatic patients

OBJECTIVE

Shunt placement during carotid endarterectomy (CEA) is often advocated to protect the ischemic penumbra in patients with symptomatic carotid stenosis. This study assesses the effect of shunt placement on postoperative stroke risk in symptomatic patients undergoing CEA.

METHODS

We queried the American College of Surgeons National Surgical Quality Improvement Program database (2016-2019) for CEA cases with complete CEA procedure-targeted data. Symptomatic patients were identified as having a preoperative diagnosis of stroke on presentation (DS), transient ischemic attack (TIA), amaurosis fugax (AF), or temporary monocular blindness (TMB). DS patients were further analyzed according to the severity of their stroke based on their modified Rankin Scale (mRS). To better assess the effect of shunt placement on stroke rate, we compared cases of CEA with patch angioplasty technique, with and without the use of intraoperative shunt. Patients who underwent carotid eversion or primary closure were excluded. Baseline demographics and perioperative outcomes were compared using Chi-square and Mann-Whitney U test. Multivariate analysis was performed to identify independent risk factors for postoperative stroke and cranial nerve injury.

RESULTS

We identified 4,652 cases of CEA with patch angioplasty in symptomatic patients, including 1,889 (40.6%) with shunt placement and 2,763 (59.4%) without. Age, race, and sex distributions were similar for both procedures. Compared to patients without shunt, those with shunt had significantly higher rates of emergency (9.1% vs 7.0%, P = .010) and non-elective surgery (40.3% vs 37.2%, P = .035), general anesthesia (97.0% vs 86.3%, P < .001), and bleeding disorders (27.2% vs 22.7%, P < .001). Thirty-day incidence of postoperative stroke was similar between patients who had shunt placement (3.2%) and those who did not (2.6%) (P = .219). Additionally, subgroup analysis failed to show any benefit of shunting on postoperative stroke regardless of preoperative symptoms or neurologic disability. In contrast, shunt placement was associated with increased rate of cranial nerve injury (4.1% vs 2.4%, P = .001). Multivariate analysis revealed that non-elective surgery (OR 1.99, 95% CI 1.36-2.91, P < .001) and DS (vs TIA/AF/TMB) (OR 1.64, 95% CI 1.12-2.41, P = .012) were predictive of 30-day postoperative stroke. After adjusting for confounders, shunt placement had no effect on stroke risk at 30 days but remained an independent risk factor for cranial nerve injury (aOR 1.87, 95% CI 1.32-2.64, P < .001).

CONCLUSIONS

In symptomatic patients undergoing CEA with patch angioplasty, shunting is associated with increased risk of cranial nerve injury without reduction in postoperative stroke risk.

Unplanned Shunting Is Associated with Higher Stroke Risk after Eversion Carotid Endarterectomy

BACKGROUND

Shunting during eversion carotid endarterectomy (eCEA) may be technically challenging. Whether shunting practice patterns modify perioperative stroke risk after eCEA is unclear. We aimed to compare eCEA outcomes based on shunting practice.

METHODS

The Vascular Quality Initiative (2011-2019) was queried for eCEAs performed for symptomatic and asymptomatic carotid stenosis. Univariable and multivariable analyses compared outcomes based on whether shunting was routine practice, preoperatively-indicated, intraoperatively-indicated, or not performed.

RESULTS

There were 13,207 eCEAs identified. Average age was 71.4 years and 59.4% of patients were male sex. Ipsilateral carotid stenosis was >80% in 45.6% and there was severe contralateral carotid stenosis in 8.6%. Early ipsilateral symptoms within 14 days of eCEA were transient ischemic attack in 5.6% and stroke in 7%. The majority of cases were performed under general anesthesia (82.7%). Electroencephalogram monitoring and stump pressures were utilized in 30.9% and 14.7%, respectively. Shunting was routine (25.4%), preoperatively-indicated (1.9%), intraoperatively-indicated (4.7%), or not implemented (68%). Preoperatively-indicated shunting was more often performed in patients with early symptomatic carotid stenosis or severe contralateral carotid stenosis. After routine shunting, preoperatively-indicated shunting, intraoperatively-indicated shunting, and no shunting, median operative duration was 110, 101, 112, and 97 min, respectively (P < 0.001), and ipsilateral perioperative stroke prevalence was 0.6%, 1.2%, 1.9%, and 0.7%, respectively (P = 0.004). On multivariable analysis, longer operative time was associated with routine shunting (MR 1.17, 95% CI 1.15-1.19, P < 0.001), preoperatively-indicated shunting (MR 1.09, 95% CI 1.04-1.15, P < 0.001), and intraoperatively-indicated shunting (MR 1.12, 95% CI 1.09-1.16, P < 0.001) compared with no shunting. Compared with no shunting, routine shunting (OR 0.91, 95% CI 0.54-1.54, P = 0.74) and preoperatively-indicated shunting (OR 1.53, 95% CI 0.47-4.99, P = 0.48) were not associated with stroke; however, intraoperatively-indicated shunting was associated with increased stroke (OR 2.74, 95% CI 1.41-5.3, P = 0.003). Shunting type was not associated with perioperative mortality.

CONCLUSIONS

Intraoperatively-indicated shunting during eCEA was associated with longest operative duration and increased perioperative stroke risk. Surgeon familiarity with shunting and planning to shunt in advance may permit more expeditious shunting and prevent stroke.

Impact of Shunting Practice Patterns During Carotid Endarterectomy for Symptomatic Carotid Stenosis

BACKGROUND

We aimed to assess the effect of surgeons' shunting practice and shunt use on the early outcomes of carotid endarterectomy (CEA) in recently symptomatic patients.

METHODS

We conducted a retrospective observational study based on a multicenter national prospective database. The Vascular Quality Initiative database (2010-2019) was queried for CEAs performed within 14 days after an ipsilateral stroke or transient ischemic attack. Surgeons were gauged as routine shunters if they shunted in >95% of CEAs, otherwise were classified as selective shunters. In-hospital stroke and death rates were compared between routine and selective shunters, stratifying by type of index event (transient ischemic attack versus stroke) and timing of CEA (≤2 versus >2 days).

RESULTS

Thirteen thousand four hundred sixty-nine CEAs were performed after a transient ischemic attack (43%) or stroke (57%), 3186 (24%) by routine shunters, and 10 283 (76%) by selective shunters. Comparing routine and selective shunters, in-hospital stroke (1.9% versus 2.4%; P=0.09) and death (0.4% versus 0.5%; P=0.73) rates were similar. A lower stroke rate (1.5% versus 4.2%; P=0.02) was achieved by routine shunters for CEA performed <2 days after an ischemic stroke. Among selective shunters, a higher stroke rate occurred in case of shunt use (2.9% versus 2.3%; P<0.01), mainly due to cases presenting with stroke (3.5% versus 2.4%; P<0.01) but not transient ischemic attack (1.8% versus 1.5%; P=0.57). Awake anesthesia was adopted in 7.8% of cases by selective shunters and in 0.8% by routine shunters, without impact on the perioperative stroke rate (1.8% versus 2.3%; P=0.349).

CONCLUSIONS

In this large national cohort, the overall outcomes of CEA were similar between routine and selective shunters. A lower postoperative stroke rate was achieved by routine shunters in CEA performed <2 days after an ischemic stroke. Among selective shunters, intraoperatively indicated shunting determined an increased stroke rate, likely due to intraoperative hypoperfusion. These data may guide the decision regarding timing of CEA and shunting intention in symptomatic patients.

Routine or selective carotid artery shunting for carotid endarterectomy (and different methods of monitoring in selective shunting)

BACKGROUND

Temporary interruption of cerebral blood flow during carotid endarterectomy can be avoided by using a shunt across the clamped section of the carotid artery. The shunt may improve the outcome. This is an update of a Cochrane review originally published in 1996 and previously updated in 2002, 2009, and 2014.

OBJECTIVES

To assess the effect of routine versus selective or no shunting, and to assess the best method for selective shunting on death, stroke, and other complications in people undergoing carotid endarterectomy under general anaesthesia.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched April 2021), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2021, Issue 4), MEDLINE (1966 to April 2021), Embase (1980 to April 2021), and the Science Citation Index Expanded (SCI-EXPANDED) (1980 to April 2021). We also searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform, and handsearched relevant journals, conference proceedings, and reference lists.

SELECTION CRITERIA

Randomised and quasi-randomised trials of routine shunting compared with no shunting or selective shunting, and trials that compared different shunting policies in people undergoing carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

Three independent review authors performed data extraction, selection, and analysis. A pooled Peto odds ratio (OR) and 95% confidence interval (CI) were computed for all outcomes of interest. Best and worse case scenarios were also calculated in case of unavailable data. Two authors independently assessed risk of bias, and quality of evidence using GRADE.

MAIN RESULTS

No new trials were found for this updated review. Thus, six trials involving 1270 participants are included in this latest review: three trials involving 686 participants compared routine shunting with no shunting, one trial involving 200 participants compared routine shunting with selective shunting, one trial involving 253 participants compared selective shunting with and without near-infrared refractory spectroscopy monitoring, and the other trial involving 131 participants compared shunting with a combination of electroencephalographic and carotid pressure measurement with shunting by carotid pressure measurement alone. Only three trials comparing routine shunting and no shunting were eligible for meta-analysis. Major findings of this comparison found that the routine shunting had less risk of stroke-related death within 30 days of surgery (best case) than no shunting (Peto odds ratio (OR) 0.13, 95% confidence interval (CI) 0.02 to 0.96, I² not applicable, P = 0.05, low-quality evidence), the routine shunting group had a lower stroke rate within 24 hours of surgery (Peto odds ratio (OR) 0.15, 95% CI 0.03 to 0.78, I² = not applicable, P = 0.02, low-quality evidence), and ipsilateral stroke within 30 days of surgery (best case) (Peto OR 0.41, 95% CI 0.18 to 0.97, I² = 52%, P = 0.04, low-quality evidence) than the no shunting group. No difference was found between the groups in terms of postoperative neurological deficit between selective shunting with and without near-infrared refractory spectroscopy monitoring. However, this analysis was inadequately powered to reliably detect the effect. There was no difference between the risk of ipsilateral stroke in participants selected for shunting with the combination of electroencephalographic and carotid pressure assessment compared with pressure assessment alone, although again the data were limited.

AUTHORS' CONCLUSIONS

This review concluded that the data available were too limited to either support or refute the use of routine or selective shunting in carotid endarterectomy when performed under general anaesthesia. Large-scale randomised trials of routine shunting versus selective shunting are required. No method of monitoring in selective shunting has been shown to produce better outcomes.

"Timing to carotid endarterectomy affects early and long term outcomes of symptomatic carotid stenosis."

OBJECTIVE

The aim of this study is to evaluate early and long-term outcomes according to the timing to carotid endarterectomy (CEA) of symptomatic carotid stenosis.

METHODS

Consecutive CEAs with selective shunting for symptomatic carotid stenosis ≥50% performed between 2009 and 2020. Patients had acute neurological impairment on presentation, defined as <5 points on the National Institutes of Health Stroke Scale(NIHSS). We grouped patients according to time between index event and CEA: the first group was operated between 0-2 days, the second group between 3 and 7 days, the third group between 8 and 14 days and the last group after 15 days. Thirty-day neurological status improvement was defined as a decrease (≥1) in the 30-day NIHSS score vs. NIHSS score immediately before surgery.

RESULTS

500 CEAs were performed. The perioperative combined stroke and mortality rate was 3.6% (18/500), representing a perioperative mortality rate of .2 (n=1) and stroke rate of 3.4% (n=17). Overall freedom from stroke was 95% at 1 year, 89 % at 6 years, and 88% at 10 years. Annual stroke rate was 0.6% after the 30-day period. Thirty-day improvement in neurologic status occurred in 103 patients (20.6%), while in 380 (76%) neurologic status was unchanged, and 17 (3.4%) experienced worsening of their neurologic status. Patients treated within 7 days from the index event had significant benefit (OR=2.6) in the 30-day neurological improvement vs. those treated after 7 days from the index event. Timing to CEA <2 days increased significantly the risk of late stroke (OR=9.7).

CONCLUSIONS

The ideal timing for performing CEA is between 3 and 7 days from the index event if NIHSS <5 as it is associated with the best rates of improvement in neurological status and durability in the long term. Very early CEA (<48 hours) was associated with increased late stroke occurrence.

Early outcomes of routine delayed shunting in carotid endarterectomy for symptomatic patients

BACKGROUND

The role of shunting during carotid endarterectomy (CEA) in symptomatic patients is unclear. The aim was to evaluate early outcomes of CEA with routine "delayed" shunt insertion, for patients with symptomatic carotid stenosis.

METHODS

we conducted a single-center retrospective review of symptomatic patients undergoing CEA (2009-2020). All CEAs were performed under general anesthesia using a standardized technique, based on delayed routine shunt insertion after plaque removal. Primary endpoints were 30-days mortality and stroke. A logistic regression was performed to identify clinical and procedural factors predictors of post-operative stroke. A literature systematic review was conducted using the terms "carotid endarterectomy" "stroke", "transient ischemic attack", "symptomatic carotid stenosis", and "shunt".

RESULTS

two-hundred-sixty-three CEAs were performed for TIA (n=178, 47%) or acute ischemic stroke (n=85, 32%). Mean delay of surgery was 6±19 days, and early CEA (<48 hours) was performed in 98 cases (37%). Conventional CEA was performed in 171 patients (67%), eversion CEA in 83 (33%). Early (30-days) mortality was 0.3%. Stroke/death rate was 2.3%. Female sex (OR 5.14, 95%CI 1.32-24.93; P=.023), use of anticoagulants (OR 10.57, 95%CI 2.67-51.86; P=.001), preoperative stroke (OR 5.34, 95%CI 1.62-69.21; P=.006), and the presence of preoperative CT/MRI cerebral ischemic lesions (OR 5.96, 95%CI 1.52-28.59; P=.013) were associated with early neurological complications. Statin medication (OR 0.18, 95%CI 0.04-0.71; P=.019) and CEA timing <2 days (OR 0.14, 95%CI 0.03-0.55; P=.005) were protective from postoperative stroke. CEA outcomes were independent from time period (P=.201) and operator's volume (P=.768). Four studies described the CEA outcomes with routine shunting in symptomatic patients, with a large variability in the selection of patients, surgical technique, and description of the results.

CONCLUSIONS

Routine delayed shunting after plaque removal seems to be a safe and effective technique, that contributed to maintain a low complication rate in neurologically symptomatic patients. Statin use and expedited timing were associated with improved outcomes using this technique.

Identifying a Safe Carotid Stump Pressure Threshold for Selective Shunting During Carotid Endarterectomy

BACKGROUND

There is no current consensus on the best criteria for selective shunting during carotid endarterectomy (CEA). The choice of continuous neurologic assessment during awake CEA, intraoperative electroencephalogram, or carotid stump pressure monitoring as the basis for shunt placement is primarily dependent on surgeon preference. Our goal is to define a safe stump pressure threshold as a guide for selective shunting.

METHODS

The study is a single-surgeon retrospective review of consecutive patients who underwent CEA under general anesthesia with selective shunting based on intraoperative stump pressure measurements from 2001 to 2019. Demographic and periprocedural variables were analyzed using standard statistical techniques.

RESULTS

Among 399 patients, 68% were male with a mean age of 70. One-third of the patients were symptomatic, with amaurosis fugax in 12%, transient ischemic attack in 7%, and stroke in 16%. In total, 60 (15%) patients underwent shunting: 34 for a confirmed preoperative acute ischemic stroke, 22 for a stump pressure <30 mm Hg, and 4 for other indications. Overall 30-day death, ischemic ipsilateral stroke, myocardial infarction, and cranial nerve palsy rates were 0.5%, 0.8%, 1.8%, and 1.0%, respectively. No strokes occurred due to hypoperfusion, and all stroke symptoms resolved prior to discharge with a mean length of stay of 1.6 days.

CONCLUSIONS

This is one of the largest contemporary series of CEA using a 30 mm Hg threshold for selective shunting that demonstrated exceedingly low 30-day death and stroke events. Intraoperative carotid stump pressure measurements are a useful guide for selective shunting and reduction in perioperative stroke complications after CEA.