General or local anaesthesia for carotid endarterectomy?

Abstract

Stroke is the most common cause of adult neurological disability in the developed world. It is the third leading cause of death in the UK. The incidence in England and Wales is .130 000 each year. Costs to the NHS and to society were estimated at approximately £7 billion in 2005; both incidence and costs are predicted to increase as the population ages. Carotid endarterectomy (CEA) is performed as a preventative procedure to prevent disabling or fatal stroke in patients with significant carotid stenosis. These patients may have been asymptomatic or have already suffered a transient ischaemic attack (TIA) or minor stroke. The aim of this article is to discuss some recent trends and changes in the perioperative management of patients presenting for carotid surgery. Large randomized prospective studies in the 1990s showed that CEA improves outcomes of symptomatic patients with .70% carotid stenosis, compared with the best medical management (reduction in arterial pressure, antiplatelet drugs, statins or diet to reduce serum cholesterol, stopping smoking, and reducing alcohol intake). The Asymptomatic Carotid Surgery Trial subsequently demonstrated that CEA improves outcome in those with carotid stenosis .60% but no symptoms, though the absolute risk reduction is lower than that in symptomatic patients and is better for younger patients (,75 yr). It has long been known that a TIA or minor stroke increases the risk of a subsequent major stroke, causing death or significant disability. However, it has recently become clear that the risk of fatal or disabling stroke is exceedingly high in the first few days after minor stroke or TIA. The risk is 10–20% within a month, and the highest risk is within 72 h after TIA or minor stroke. In addition, the greatest benefits from CEA are gained if it is performed within 2 weeks of the last symptom. This target has now been incorporated into recent NICE guidelines and has led to important changes to UK practice with an imperative that CEA should be performed within 2 weeks of neurological symptoms and within 48 h if possible. Because there are risks associated with CEA, patients only benefit from CEA when perioperative risks are low and medium-term survival (2 yr or more) is good, so all possible attempts should be made to minimize risks. The major complications of CEA are intraand postoperative stroke, myocardial infarction (MI), and death; their combined 30 day incidence should be ,5% in centres performing surgery. Any co-morbidities, such as ischaemic heart disease, hypertension, diabetes, and chronic obstructive pulmonary disease, should be optimized appropriately before surgery but the imperative to perform CEA urgently poses increased challenges for the medical, surgical, and anaesthetic teams as the time for optimization of co-morbidities is reduced. Furthermore, arterial pressure is actually more labile in the 2 weeks after a stroke, so is potentially more difficult to control. Studies in these areas are ongoing but recent reviews have emphasized the need for control of arterial pressure before, during, and after CEA.