Perioperative stroke is a devastating complication associated with significant morbidity and mortality ranging from 20% to 60%. Approximately 50% of perioperative strokes occur within postoperative days 1–3, with a significant proportion of these occurring intraoperatively. Most perioperative strokes are ischemic, primarily embolic after cardiac and carotid surgeries, and embolic or thrombotic after noncardiac surgeries. Hemorrhagic strokes comprise only 1–4% of all perioperative strokes.
Incidence of Perioperative Stroke
The incidence of stroke varies with the type of surgery and the patient’s comorbidities and is highest with cardiac, carotid, and neurologic surgeries (Figure 26-1).1 The incidence of stroke after cardiac surgeries ranges from 0.4% to 14% in different studies. The incidence of stroke after carotid artery stenting (CAS) and carotid endarterectomy (CEA) has been reported to be 3.6% and 2.2%, respectively. After neurological surgeries, the incidence of stroke has been reported to be 0.6%.
Incidence of Perioperative Stroke.
The incidence of overt perioperative stroke after noncardiac, noncarotid, nonneurologic surgery in multiple studies has been reported to be less than 1% overall; less than 0.5% for patients without a history of prior stroke and 1–2% for patients with a history of prior stroke. The incidence of covert stroke after elective noncardiac surgeries in patients ≥ 65 years old has been reported to be 7% and the incidence of cognitive decline in this group of patients at 1 year was reported to be 42%.2
Mechanisms and pathophysiology of perioperative stroke vary with the type of surgery and risk factors. Large vessel and cardioembolic etiologies are the most common, especially in the anterior circulation, though the stroke etiology may not be classified in 25–30% of the cases. Inflammation and hypercoagulability in the perioperative period predispose to thrombogenesis and plaque rupture, especially in patients with multiple preexisting risk factors. Cardioembolic ischemic stroke may occur in the perioperative setting in patients with prior or new-onset atrial fibrillation (compounded by interruption of antithrombotics in the perioperative period) or in patients with direct manipulation of the heart or aortic arch during cardiac surgeries. Another potential mechanism by which perioperative ischemic stroke may occur is cerebral hypoxia in the setting of anemia and hemodilution, reduction in cardiac output, and antagonism of ß-2 mediated cerebral vasodilation (e.g., by weakly ß-1 or nonselective beta-blockers such as metoprolol) resulting in unopposed α-receptor mediated vasoconstriction.
For patients at high risk of perioperative stroke, a risk-benefit discussion should occur prior to proceeding with elective surgery along with risk factor modification and discussion on the appropriate timing of the elective surgery.
Any modifiable cardiovascular risk factors should be optimized prior to elective surgeries (Table 26-1).1...