Carotid endarterectomy: indications and benefits

Giancarlo Bracale, Massimo Porcellini, Benedetto Bernardo, Lucio Selvetella,
Maria Baldassarre

Cattedra e Scuola di Specializzazione in Chirurgia Vascolare
Università Federico II,  Napoli

Though much progress has been made in carotid surgery in the last years, there is still controversy to perform emergent, urgent, or elective surgery on patients with unstable strokes, slowly progressing strokes and crescendo TIA's, as well as on asymptomatic patients with significant stenosis.
As to indications in cases for which carotid endarterectomy effectiveness is undoubtful, the American Health Association has set the following guide lines: 1) symptomatic patients with unilateral carotid stenosis >= 70% and intervention effected by a surgeon, whose surgical morbidity and mortality is less than 6%; 2) asymptomatic carotid stenosis >= 60% and intervention effected by a surgeon, whose surgical morbidity and mortality is less than 3%. Furthermore, carotid endarterectomy is acceptable also for carotid stenoses within 50-60%, with soft or ulcerated plaque, which has caused recurrent TIA events.
A number of factors are involved in the incidence of stroke: plaque morphology, status of cerebral collateral circulation, status of the opposite carotid, external carotid, and vertebral arteries.
There are several methods of perioperative cerebral monitoring; the stump pressure measure, though it furnishes valid informations, is not 100% reliable; evoked potentials, continuous EEG and TransCranial Doppler are much more reliable methods but they are available only in some Centres of Vascular Surgery. Their use is justified in cases of bilateral stenosis or associated lesions, when a temporary shunt is not available or its application is not suggested.
Methods of cerebral protection during carotid clamping includes the use of a temporary bypass shunt, that is employed routinely or selectively on the basis of an assessment of cerebral circulation, or never by different surgeons.
The results of ECST and NASCET trials show that a symptomatic carotid stenosis greater than 70% in patients without persisting neurological deficit should be treated by surgery with good results and a decrease of the long-term incidence of stroke compared with medical therapy.
Also selected asymptomatic patients with high-grade carotid stenosis may benefit from carotid endarterectomy with a reduced incidence of long-term stroke.
Though these clear advantages, conventional surgery is still associated to appreciable perioperative morbidity (3-7%), including also cranial nerve lesions, wound infections, neck ematomas and cardiovascular complicances. So that it was unavoidable that angioplastique and stenting techniques could invade also the sector of cerebrovascular diseases, though the different physiopathologic aspects comparing to peripheral districts. But it must be underlined that short and long term results and over all at distance results are still not standardised, being therefore of difficult interpretation.
On the contrary, owing to several randomised trials conducted on patients with cerebrovascular insufficiency (NASCET, ECST, ACAS), carotid endarterectomy can be at moment defined the "gold standard" in the treatment of patients affected by carotid bifurcation atherosclerosis and the best Stroke prevention procedure.