Postoperative ischemic stroke is a rare but major complication associated with significant morbidity, mortality, and prolonged hospitalization. Its reported incidence varies widely depending on the type of surgery and patient population, ranging from less than 0.1% after low-risk noncardiac procedures to more than 5% in selected high-risk cardiac and vascular surgeries. Understanding the risk factors that predispose patients to postoperative ischemic stroke is essential for perioperative risk stratification, informed consent, and the development of targeted preventive strategies.
Patient-related factors play a central role in determining postoperative stroke risk. Advanced age is consistently one of the strongest predictors, reflecting the cumulative burden of cerebrovascular disease and reduced physiologic reserve. A prior history of ischemic stroke or transient ischemic attack markedly increases the likelihood of recurrence in the perioperative period. Chronic conditions such as hypertension, diabetes mellitus, hyperlipidemia, and smoking contribute to atherosclerotic disease and impaired cerebrovascular autoregulation. Atrial fibrillation, whether pre-existing or newly diagnosed, is particularly important due to its association with cardioembolic stroke, especially when perioperative anticoagulation is interrupted. Chronic kidney disease, heart failure, and anemia have also been linked to higher postoperative stroke risk, likely through a combination of endothelial dysfunction, inflammation, and impaired oxygen delivery.
Surgery-related factors also substantially influence the risk of postoperative ischemic stroke. Cardiac surgery, especially procedures involving cardiopulmonary bypass, carries the highest risk due to aortic manipulation, embolization of atheromatous debris, and systemic inflammatory responses. Major vascular surgeries, such as carotid endarterectomy and aortic repair, also pose significant risk through direct arterial manipulation and potential cerebral hypoperfusion. Certain noncardiac surgeries, including major orthopedic and thoracic procedures, have been associated with increased stroke risk, particularly in patients with underlying cardiovascular disease. Prolonged operative time and emergency surgery further amplify risk, reflecting greater physiologic stress and reduced opportunity for preoperative optimization.
Intraoperative and anesthetic factors contribute to both stroke risk and the degree of injury in the event of a stroke. Episodes of sustained intraoperative hypotension may compromise cerebral perfusion, especially in patients with impaired autoregulation or significant carotid stenosis, leading to poorer outcomes if stroke occurs. Conversely, perioperative hypertension can precipitate plaque rupture or promote hemorrhagic transformation of ischemic injury. Embolic phenomena may arise from air, thrombus, or atherosclerotic debris during instrumentation or intravascular catheter use. The type of anesthesia itself appears less important than meticulous hemodynamic control, oxygenation, and avoidance of large fluctuations in carbon dioxide levels, all of which influence cerebral blood flow.
Postoperative factors are increasingly recognized as critical determinants of ischemic stroke risk. New-onset atrial fibrillation is common after major surgery and is strongly associated with early postoperative stroke. A hypercoagulable state induced by surgical stress, inflammation, and immobility can promote thrombus formation, particularly when combined with delayed resumption of antithrombotic therapy. Postoperative anemia, infection, and hypoxia further exacerbate cerebral vulnerability. Early neurological symptoms may be subtle or masked by sedation and analgesia, leading to delayed diagnosis and treatment.
Postoperative ischemic stroke results from a complex interplay of patient-specific risk factors, surgical characteristics, and perioperative physiological disturbances. Recognition of these factors enables clinicians to identify high-risk individuals, optimize perioperative management, and implement vigilant postoperative monitoring. As surgical populations continue to age and accumulate comorbidities, heightened awareness and multidisciplinary prevention strategies will remain central to reducing the burden of postoperative stroke.