Makindo Medical Notes

It is recommended that CEA is offered in Carotid stenosis of 50-99% (NASCET) or 70-99% (ECST) in those with TIA or non-disabling stroke preferably within 48 hours but not later than 2 weeks

Diagram

Evidence and Indications

• Carotid endarterectomy is not a new operation having been developed in the 1950s. There was a concern that there was no real evidence base to select those who would benefit and surgery rates were higher with no clear evidence base. However, with several well-publicized trials its role in the management of stroke has become better defined.
• CEA should ideally be performed within 2 weeks of TIA as this is the time at which further stroke occurs and many are now operating within days. There is some evidence to suggest that even to delay CEA for several months means that it has no benefit. CEA is of no use if the vessel is occluded as any downstream damage has already occurred.
• CEA are only done following TIA or mild stroke with good recovery and the artery is patent with a 70% + stenosis. There are some who would operate on lesser degrees of symptomatic stenosis such as 50-70% but the benefits are less so. It is recommended that to minimise complications that the operator and team should perform a minimum number of procedures per year and have a known risk of complications.
• The most important and influential trial was the North American Symptomatic Carotid Endarterectomy Trial (NASCET). Patients were randomised to either medical or surgical therapy for TIA or mild, disabling stroke ipsilateral to a 70% to 99% narrowing of the internal carotid artery. The evidence was that the best outcome was in those treated surgically. Again patients with moderately severe, symptomatic carotid stenosis were shown to have clear benefits with surgery in the European Carotid Surgery Trial (ECST) which looked at patients with slightly less degree of stenosis. There are benefits but less marked in those with 50% to 69% symptomatic stenosis.
• % stenosis = ( 1 - ( minimal diameter ) / ( post-stenotic diameter ) ) - 100%.

Investigations

• Investigations of carotid artery stenosis include most commonly USS Doppler.
• Often a second test may be used to confirm stenosis
• Contrast enhanced MRA or CT angiography may be used.

Procedure

• The procedure can be done under local anaesthesia or General anaesthesia in some cases. The carotid artery is accessed through an incision in the neck. Heparin may be given. The carotid is clamped above and below the incision, and a shunt may be inserted to maintain blood flow.
• The Plaque lining the artery is removed and the shunt is taken out and the incisions are repaired or a patch may be used to close the artery. The procedure lasts between 60 and 90 minutes and usually requires an overnight stay in the ICU to monitor blood pressure and neurologic status.
• Patients usually are able to go home the next day. Postoperative activity restrictions are very few and most patients are back to full activity in one week.

Complications

Best Medical Therapy

• Carotid endarterectomy is done in addition to optimising medical treatment
• Smoking cessation, antiplatelets (aspirin 75 mg od or clopidogrel 75 mg od) and high dose statin and management of hypertension.
• Exercise and other lifestyle dietary measures and alcohol usage are wise.

Secondary prevention of stroke with carotid surgery

There is some benefit of surgery for 50-70% stenosis, except in women and those with ocular events. The benefit of surgery is modest in patients with ocular events, lacunar infarcts, contralateral carotid occlusion, and the collapse of the vessel distal to very severe stenosis. The benefit of surgery is greatest within days of the relevant cerebrovascular event and declines rapidly over time so that it is minimal after 3-6 months. There is little benefit for surgery in patients with asymptomatic carotid stenosis