Anaesthesia 2025, 80, 109–111
doi:10.1111/anae.16456
Science Letter
Safety of anaesthesia techniques in patients undergoing
carotid endarterectomy: a systematic review with metaanalysis of randomised clinical trials
Each year, approximately 3000–3500 patients undergo
respiratory complications; quality of life one month after
carotid endarterectomy in the UK, and over 150,000
surgery; and haemodynamic parameters. Screening and
worldwide [1, 2]. It is thought that the selection of
data collection were conducted in duplicate by independent
anaesthetic method – whether cervical plexus block,
reviewers. We assessed risk of bias in individual studies
general anaesthesia or a mix of both – can impact
using the Risk of Bias 2 tool and judged the certainty of
haemodynamic parameters differently and the oxygenation
evidence according to GRADE recommendations (online
and perfusion of the brain and heart. This variability may
Supporting Information Figure S1).
have an impact on the risk of stroke, myocardial infarction
We categorised the interventions into four groups for
and mortality [3]. We conducted a systematic review to
the Bayesian network meta-analyses: epidural; regional (i.e.
compare the safety and clinical outcomes of different
cervical plexus block and/or local infiltration); general; and
anaesthetic techniques in patients undergoing carotid
combined regional and general anaesthesia. We also
endarterectomy.
performed Bayesian pairwise meta-analyses comparing
This analysis was based on data from a systematic
regional with general anaesthesia. Overall, 24 studies
review, the protocol of which was registered prospectively.
encompassing 5341 patients were included in the analyses.
We included randomised clinical trials that enrolled patients
We did not find any significant differences between the
aged ≥ 18 y undergoing carotid endarterectomy. The
interventions for the primary outcomes of stroke and
studies included comparisons between any two anaesthesia
myocardial infarction within 30 days of surgery (Table 1
techniques (general, local/regional, combined regional and
and Fig. 1). However, there was significantly less use of an
general). Our primary outcomes were stroke and myocardial
arterial shunt with regional compared with general
infarction within 30 days of surgery. We also included
anaesthesia (relative risk (95% credible interval) 0.33
studies
reporting
postoperative
pain
data
on
within
death
24 h;
within
30 days;
(0.17–0.66), Table 1). No significant differences were found
arteries
shunted;
for the remaining outcomes.
postoperative haematoma; time course of arterial occlusion;
Our study did not yield results to inform decision-
patient satisfaction; surgeon satisfaction; postoperative
making regarding choice of anaesthetic technique for
cognitive dysfunction; duration of surgery, ICU stay and
carotid endarterectomy. No significant differences were
hospital stay; need for reintervention; cranial nerve injury;
observed for most outcomes. However, readers should not
Table 1 Results of the Bayesian pairwise meta-analyses comparing regional with general anaesthesia for four outcomes.
Outcome
Relative risk (95%CrI)
Probability of
improvement with
regional anaesthesia
I2
Certainty of evidence according
to GRADE
Stroke
(seven studies; 4184 patients)
1.05 (0.64–1.90)
45.0%
0.0%
Very low
Due to risk of bias and relevant imprecision
Myocardial infarction
(six studies; 3891 patients)
1.08 (0.53–2.23)
41.4%
0.0%
Very low
Due to risk of bias and relevant imprecision
Mortality
(seven studies; 4188 patients)
0.76 (0.39–1.51)
81.1%
0.0%
Very low
Due to risk of bias and relevant imprecision
Need for arterial shunt
(11 studies; 4356 patients)
0.33 (0.17–0.66)
99.7%
78%
Low
Due to heterogeneity and imprecision
95% CrI, 95% credible interval.
© 2024 Association of Anaesthetists.
109
Science Letter
Figure 1 Forest plots with the comparative network effect sizes of four interventions. Black squares, estimated network effect
sizes; black bars, 95% credible intervals. Values are reported as relative risks. Note: some effect sizes fall outside the range of
0.1–10, with some black squares non-visible. Shunt, need for arterial shunt; regional, cervical plexus block and/or local
infiltration; epidural, epidural anaesthesia; general, general anaesthesia; NA, not available.
interpret these findings as evidence of equivalence as they
inadequate sedation might lead to tachycardia and
may reflect insufficient data.
hypertension, increasing the risk of myocardial ischaemia in
While our findings show reduced use of arterial shunt
this high-risk cohort of patients. This adds complexity, as
with the use of regional anaesthesia, there is a possibility
different techniques may affect key outcomes like stroke
that this result is due to chance, given the number of
and myocardial infarction differently. Future research might
analyses performed. Applying a Bonferroni correction
consider evaluating composite or more critical outcomes,
would render this significant difference non-significant. Our
such as mortality.
results also indicate that regional anaesthesia may reduce
Although
our
findings
do
not
provide
strong
mortality within 30 days of surgery (Table 1 and Fig. 1).
evidence to inform clinical decision-making, they do
However, it is important to emphasise that this was not
suggest a potential difference between anaesthetic
statistically significant, the certainty of evidence is very low,
techniques in relation to important outcomes such as
and this finding should not be used to inform clinical
the need for arterial shunt and mortality. These findings
practice.
are consistent with observational data and may be
Other researchers have summarised data from
associated with the incidence of stroke and myocardial
randomised trials and observational studies [3–5]. While
infarction [3, 5]. As such, our results underscore the
observational data suggest improved outcomes with
need for further research to determine whether any
regional anaesthesia [3, 5], including a reduced incidence of
specific technique or combination of techniques may
stroke, myocardial infarction and death, these results were
improve patient outcomes.
not confirmed by a previous summary of randomised
studies [4], and not by our updated analysis.
In conclusion, the current evidence does not provide
robust support for the selection of any specific anaesthetic
While regional anaesthesia may improve outcomes by
technique for carotid endarterectomy. We did not observe
blocking nociceptive pathways and increasing cerebral
significant differences for most outcomes, and the one
blood flow, it is also possible that uncovered nerve fibres or
observed difference may be attributable to chance.
110
© 2024 Association of Anaesthetists.
13652044, 2025, 1, Downloaded from https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/10.1111/anae.16456 by Test, Wiley Online Library on [17/12/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License
Anaesthesia 2025, 80, 109–111
Acknowledgements
This systematic review was prospectively registered with
PROSPERO (CRD42024505658).
Clıstenes C. de Carvalho
Idrys H. L. Guedes
Federal University of Campina Grande,
Campina Grande, Brazil
Email: clistenescristian@hotmail.com
Anna L. S. Holanda
Centro Universit
ario Unifacisa,
Campina Grande, Brazil
Anaesthesia 2025, 80, 109–111
endarterectomy. Ann Vasc Surg 2023; 88: 9–17. https://doi.
org/10.1016/j.avsg.2022.08.007.
3. Hajibandeh S, Hajibandeh S, As A, Torella F, Antoniou GA. Metaanalysis and trial sequential analysis of local vs. general
anaesthesia for carotid endarterectomy. Anaesthesia 2018; 73:
1280–9. https://doi.org/10.1111/anae.14320.
4. Rerkasem A, Orrapin S, Howard DPJ, Nantakool S, Rerkasem K.
Local versus general anaesthesia for carotid endarterectomy.
Cochrane Database Syst Rev 2021; 10: CD000126. https://doi.
org/10.1002/14651858.CD000126.
5. Harky A, Chan JSK, Kot TKM, et al. General anesthesia versus
local anesthesia in carotid endarterectomy: a systematic review
and meta-analysis. J Cardiothorac Vasc Anesth 2020; 34: 219–
34. https://doi.org/10.1053/j.jvca.2019.03.029.
doi:10.1111/anae.16456
Yuri S. C. Costa
Hospital Santa Izabel/SCM-BA,
Salvador, Brazil
Supporting Information
Additional supporting information may be found online via
References
1. Watson S, Johal A, Li Q, et al. National Vascular Registry:
2023 State of the Nation Report. 2023. https://www.vsqip.org.
uk/wp-content/uploads/2024/04/NVR-2023-State-of-the-NationReport.pdf (accessed 24/09/2024).
2. Brown CS, Osborne NH, Hider A, Kemp MT, Albright J, Scheidel
C, Henke PK. Assessment of determinants of value in carotid
© 2024 Association of Anaesthetists.
the journal website.
Figure S1. Risk of bias at outcome level according to Risk of
Bias 2 tool: (a) stroke; (b) myocardial infarction; (c) mortality;
(d) need for arterial shunt.
111
13652044, 2025, 1, Downloaded from https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/10.1111/anae.16456 by Test, Wiley Online Library on [17/12/2024]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License
Science Letter