Identifying risk factors and proposing a risk-profile scoring scale for perioperative ischemic complications in carotid endarterectomies

BACKGROUND: Carotid endarterectomy can reduce the risk of stroke in patients with severe symptomatic carotid artery stenosis, but the benefit of the procedure can be significantly influenced-by the risk of perioperative ischemic complications. We conducted a retrospective study in order to assess the safety of the procedure in a low-volume single Neurosurgical Department and identify potential risk factors that are associated with the occurrence of a perioperative ischemic event. METHODS: The records of 218 procedures performed over a period of ten years were reviewed. The records were abstracted for demographics, neurologic history, degree of stenosis, comorbidities and ischemic complications within 30 days of surgery. RESULTS: The overall mortality was zero but 12 patients (5.5%) suffered from a perioperative ischemic event, half of which were non-reversible; four of them had a complete stroke and 2 an amaurosis. A postoperative ischemic complication was more likely for patients with a history of complete stroke (RR, 5.93; 95% CI, 1.7-23.0), contralateral vessel stenosis (RR, 11.6; 95% CI, 1.6-244.0), diabetes mellitus (RR: 3.3; 95% CI: 1.13-10.09), hypercholesterolemia (RR: 3.4; 95% CI: 1.13-10.44) and hypertriglyceridemia (RR: 4.6; 95% CI: 1.31-12.42). Using these factors we created a scoring system that stratifies patients into low, medium and high risk. All but two of the patients with perioperative ischemic events fall into the high risk group. Patients with the aforementioned risk factors may have an elevated risk of adverse outcomes. CONCLUSIONS: Carotid endarterectomies can be performed with exceptional safety in low-volume-centers, but patients with a history of stroke, contralateral internal carotid artery stenosis and three or more atherosclerotic factors are at a higher risk of perioperative ischemic complications. Our scoring system could prove a valuable tool when weighting the risk-to-benefit ratio for an individual patient.