Your recently published ‘Regional or general anaesthesia for carotid endarterectomy’ debate1–3 was interesting, but there may be more to the story when comparing regional and general anaesthetic techniques.
First, patients undergoing carotid endarterectomy have significant comorbidity and may experience significant cardiovascular and neurological complications during surgery, which obviously contribute to operative morbidity and mortality. One's ability as an anaesthetist to ‘intervene’ when looking after such patients is governed in part by how early one receives information about such complications – the earlier information is received, the sooner meaningful interventions can be made which can terminate or treat the complication. Thus, the neurological status of patients with a cross-clamped common carotid artery can be determined earlier when they are awake compared with any of the neurological monitoring modalities utilised under general anaesthesia.4 Titration of blood pressure and additional oxygenation against the patient's neurological status may then be used to help reverse that complication.5,6
Second, in their discussion of the general anaesthesia versus local anaesthesia for carotid surgery (GALA) trial, Unic-Stojanovic and Jovic3 pointed out the divergence of the survival curves of patients in the GALA trial with a smaller percentage of patients in the general anaesthesia group surviving for 1 year. Although this difference did not achieve statistical significance, the curves were still diverging at 12 months without explanation, yet, because of a lack of funding, there was no follow-up after 12 months.
In the GALA trial,7 underpowered as it was to detect a difference in mortality, the only significant difference between the two groups was the percentage of patients who received internal carotid artery shunting during the procedure. It is intriguing whether this in itself might in some way contribute to outcome. There is other evidence available that shunting may itself be deleterious to patient outcome, including increased risk of carotid re-stenosis8 and alterations in early postoperative cognitive function.9
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1. Licker M. Regional or general anaesthesia for carotid endarterectomy: does it matter? Eur J Anaesthesiol
2. Cedergreen P, Swiatek F, Nielsen HB. Local anaesthesia for carotid endarterectomy. Pro: protect the brain. Eur J Anaesthesiol
3. Unic-Stojanovic D, Jovic M. Local anaesthesia for carotid endarterectomy. Con: decrease the stress for all. Eur J Anaesthesiol
4. Guay J, Kopp S. Cerebral monitors versus regional anesthesia to detect cerebral ischemia in patients undergoing carotid endarterectomy: a meta-analysis. Can J Anaesth
5. Stoneham MD, Warner O. Blood pressure manipulation during awake carotid surgery to reverse neurological deficit after carotid cross-clamping. Br J Anaesth
6. Stoneham MD, Martin T. Increased oxygen administration during awake carotid surgery can reverse neurological deficit following carotid cross-clamping. Br J Anaesth
7. Lewis SC, Warlow CP, Bodenham AR, et al. General anaesthesia versus local anaesthesia for carotid surgery (GALA): a multicentre, randomised controlled trial. Lancet
8. Mazul-Sunko B, Hromatko I, Tadinac M, et al. Subclinical neurocognitive dysfunction after carotid endarterectomy: the impact of shunting. J Neurosurg Anesthesiol
9. Hudorovic N, Lovricevic I, Hajnic H, et al. Postoperative internal carotid artery restenosis after local anesthesia: presence of risk factors versus intraoperative shunt. Interact Cardiovasc Thorac Surg