We thank Dr Stoneham1 for his interest in and his insightful comments concerning the previously published Pro & Con debate about general or regional anaesthesia for carotid endarterectomy.2–4
First, there is still insufficient evidence to support the use of regional anaesthesia over general anaesthesia in patients undergoing carotid endarterectomy.3 More importantly, whichever anaesthetic technique is chosen, cerebral blood flow should be optimised, cardiac stress minimised and the risk of ischaemia decreased by maintaining a normal-to-high perfusion pressure. In the GALA (general anaesthesia versus local anaesthesia for carotid surgery) study discussion, the authors pointed out that carotid surgery needs a small incision and it is associated with minimal blood loss and ischaemia re-perfusion compared with many other vascular operations. Thus, despite of severe comorbidity, the stress response is likely to be small and the frequency of complications may also be expected to be small.5
With regard to the estimated 30-day cardiac event rates (cardiac death and myocardial infarction), asymptomatic carotid surgical interventions are low risk (<1%), and symptomatic carotid surgery is intermediate-risk surgery (1 to 5%).6 Endarterectomy has an inherent risk of perioperative stroke. But, one-quarter of perioperative strokes associated with carotid endarterectomy occur during the procedure, of which the large majority are embolic.7 Far fewer strokes are the result of low cerebral blood flow, because of low systemic pressure and contralateral disease, poor collateral circulation or reduced cerebrovascular reserve.7
Second, the GALA study failed to find a significant difference between the two anaesthetic techniques in terms of the survival rate at 1 year (P = 0.094).5 A sufficiently large (about 20 000 patients) randomised trial should be performed in the future to reliably confirm or refute the possible effect on mortality.
The results of the GALA study showed that regional anaesthesia was associated with a substantial reduction in the use of arterial shunts (14% regional anaesthesia vs. 43% general anaesthesia), but shunting was used purely at the discretion of the clinicians (at least in the general anaesthesia group) rather than because of detected neurological deficit.5 Surprisingly, the shunt was routine in 50% of general anaesthesia patients. On the other hand, in 40% of regional anaesthesia patients, the shunt was inserted without neurological deterioration.8 Accordingly, and accepting the randomised criteria of the study, it can be assumed that an equal number of 8 to 14% shunts would have been necessary in general anaesthesia patients, instead of the 43% used. A potential advantage of this study, to demonstrate an additional benefit over general anaesthesia in accurately predicting the need for a shunt, was lost, as the study did not include only selective shunting.8
Acknowledgements related to this article
Assistance with the reply: none.
Financial support and sponsorship: none.
Conflicts of interest: none.
1. Stoneham MD. Regional or general anaesthesia for carotid endarterectomy. Eur J Anaesthesiol
2. Licker M. Regional or general anaesthesia for carotid endarterectomy: does it matter? Eur J Anaesthesiol
3. Unic-Stojanovic D, Jovic M. Local anaesthesia for carotid endarterectomy: con: decrease the stress for all. Eur J Anaesthesiol
4. Cedergreen P, Swiatek F, Nielsen HB. Local anaesthesia for carotid endarterectomy. Pro: protect the brain. Eur J Anaesthesiol
5. Lewis SC, Warlow CP, Bodenham AR, et al. General anaesthesia versus local anaesthesia for carotid surgery (GALA): a multicentre, randomised controlled trial. Lancet
6. Kristensen SD, Knuuti J, Saraste A, et al. 2014 ESC/ESA guidelines on noncardiac surgery: cardiovascular assessment and management. Eur Heart J
7. Erickson KM, Cole DJ. Carotid artery disease: stenting vs endarterectomy. Br J Anaesth
2010; 105 (Suppl 1):i34–i49.
8. Moulakakis KG, Avgerinos ED, Liapis CD. The hypothesis regarding the benefit of carotid endarterectomy under locoregional anesthesia in prevention of stroke may be unanswered. Angiology