Perioperative stroke is a serious medical event that can occur around the time of surgery. It represents a significant concern for patients and healthcare providers due to its potential impact on recovery and long-term health.
What is Perioperative Stroke?
Perioperative stroke refers to a brain infarction, either ischemic or hemorrhagic, that develops during surgery or within 30 days following a surgical procedure, including after recovery from anesthesia. While rare in low-risk non-vascular surgeries, with an incidence around 0.1-1.9%, the risk can rise considerably in high-risk cardiac or neurosurgical procedures, potentially exceeding 5%.
Most perioperative strokes are ischemic, meaning they result from a blockage of blood flow to the brain. Hemorrhagic strokes, caused by bleeding in the brain, are less common in this setting, accounting for approximately 1-4% of all perioperative strokes. The onset of symptoms can vary, with many strokes occurring, on average, seven days after general surgery, though intraoperative events are more common in high-risk operations like cardiovascular surgery.
Why Does It Happen?
Perioperative strokes arise from patient-specific characteristics and surgical factors. Advanced age is a significant patient-related risk factor, with the incidence of perioperative stroke rising to 7% in patients older than 65 years. A history of previous stroke or transient ischemic attack (TIA) also increases susceptibility.
Pre-existing medical conditions like hypertension, diabetes mellitus, atrial fibrillation, and carotid artery disease are also associated with a higher risk. Renal insufficiency and chronic obstructive pulmonary disease also contribute to risk.
Surgical factors also play a role, including the type and duration of the procedure. Major vascular and cardiac surgeries carry a higher risk due to the manipulation of large blood vessels and the potential for embolic events. Intraoperative complications such as significant blood pressure fluctuations, including both high and low blood pressure, can compromise blood flow to the brain. Additionally, inflammation and a hypercoagulable state, where blood is more prone to clotting, can be triggered by the surgical process itself.
Recognizing and Diagnosing Perioperative Stroke
Recognizing a perioperative stroke can be challenging because the signs and symptoms may be subtle or masked by the effects of anesthesia and pain medications. Common indicators of a stroke include new weakness on one side of the body, difficulty speaking or understanding speech, vision changes, or sudden confusion. These symptoms might be mistaken for other postoperative complications, delaying diagnosis.
Prompt recognition by medical staff and family is important. If a stroke is suspected, immediate brain imaging is performed to confirm the diagnosis and determine the type of stroke. A non-contrast computed tomography (CT) scan is often the initial imaging choice to quickly differentiate between an ischemic and hemorrhagic stroke. Magnetic resonance imaging (MRI) can provide more detailed information about the extent of brain damage.
Minimizing Risk and Treatment Approaches
Medical teams employ strategies to minimize the risk of perioperative stroke. A thorough preoperative assessment helps identify patients at higher risk by evaluating their medical history and comorbidities. Optimizing pre-existing conditions, such as controlling blood pressure and glucose levels, is important. Guidelines suggest delaying elective surgery for at least 6 months, and preferably 9 months, after a stroke to reduce the risk.
During surgery, blood pressure management is important, especially in patients at moderate or high risk. Avoiding significant drops in blood pressure helps ensure adequate blood flow to the brain. The appropriate use of antiplatelet or anticoagulant medications before and after surgery is carefully considered, balancing the risk of stroke with the risk of bleeding.
If a perioperative stroke occurs, acute management focuses on restoring blood flow to the affected brain region and providing supportive care. For ischemic strokes caused by a clot, interventions like intravenous thrombolysis (clot-busting medication) can be administered within 4.5 hours of symptom onset if appropriate. Mechanical thrombectomy, a procedure to physically remove a large blood clot, may be performed for large vessel occlusions. Postoperative care includes close neurological monitoring, managing complications like fever or arrhythmias, and addressing factors such as volume depletion or blood loss.
Navigating Recovery
The recovery process after a perioperative stroke varies significantly among individuals, depending on the stroke’s severity and the specific areas of the brain affected. Rehabilitation helps regain lost functions and improve quality of life. This often begins as soon as 24 to 48 hours after the stroke, while the patient is still in the hospital.
Rehabilitation programs typically involve a multidisciplinary team, including physical therapists, occupational therapists, and speech therapists. Physical therapy focuses on improving muscle strength, coordination, and mobility, helping patients relearn how to walk or use mobility aids. Occupational therapy assists with daily living skills, while speech therapy addresses difficulties with speaking, understanding, reading, and writing. Continued medical follow-up is necessary to manage any ongoing challenges and to address underlying risk factors to help prevent future strokes.