Introduction: Carotid endarterectomy (CEA) guidelines in symptomatic carotid stenosis are based on NASCET and ECST criteria with 70% or greater carotid stenosis as estimated from a catheter angiogram, the major determinant for CEA. This has several problems: (1) discrepancy between the methods used to estimate angiographic stenosis: 70% stenosis on ECST is a 50% stenosis on NASCET; (2) discrepancy between NASCET and ESCT angiographic criteria and duplex ultrasound, now often the sole method of estimating stenosis; (3) estimates of stenosis ignore the fact that the risk of stroke is also based on plaque stability and number of ischaemic events. We investigated the outcome of CEA in 30 symptomatic patients with 70% or less carotid stenosis.
Methods: As a retrospective case series we reviewed clinical events, timing of events, imaging results, surgical complications and stroke-free follow-up in 30 patients over a 23 year period presenting to a major tertiary hospital, with TIA or minor stroke, and 70% or less carotid stenosis.
Results: Eighteen patients had small strokes, 7 TIAs and 5 ocular events; 21 patients had ultrasonogaphic features of unstable plaque; 18 patients experienced multiple events before CEA. All had haemorrhagic, ruptured plaque at CEA; none had significant post-operative complications and for up to 20 years after surgery only 1 patient suffered a further stroke/TIA.
Conclusion: To predict the likelihood of major stroke in symptomatic carotid stenosis and the benefit of CEA, plaque stability and number of ischaemic events may be as important as an estimate of the degree of stenosis.