Why do some patients with > 80% stenosis of the internal carotid artery not undergo surgery? A retrospective review.

Background: Carotid endarterectomy is known to benefit both symptomatic and asymptomatic patients with high-grade internal carotid artery stenosis. Duplex scanning is the 'gold standard' for non-invasive preoperative investigation of carotid artery stenosis. The aim of the present study was to analyse the indications for duplex scanning and to identify other factors that influenced the management of patients with high-grade stenosis who did not undergo carotid endarterectomy. Methods: A total of 271 patients was observed to have > 80% stenosis of the internal carotid artery on duplex scanning during the period of review. Of these patients, 85 did not undergo carotid endarterectomy. The vascular laboratory database and hospital records of these patients were retrospectively reviewed. Results: The indications for requesting a carotid duplex scan in the 85 patients were transient ischaemic attack (22%), stroke (25%), symptomatic bruit (7%), asymptomatic bruit (12%), and stroke and symptomatic bruit combined (7%). Falls and preoperative carotid assessment prior to coronary surgery were the commonest indications in the remaining patients. The main risk factors were cardiac (68%), hypertension (60%), respiratory (21%), diabetes (25%), peripheral vascular disease (19%), neoplasm (16%) and renal disease (16%). Twenty-five per cent of the patients were over 80 years of age. Conclusion: In the present study risk factors associated with increased perioperative morbidity and mortality were the commonest explanation for patients with high-grade stenosis of the internal carotid artery not undergoing surgery. These patients would generally not meet the inclusion criteria for the major carotid endarterectomy trials.