Cerebral small-vessel disease and postoperative delirium in elderly non-cardiac surgical patients.

Abstract

Postoperative delirium is common in elderly surgical patients and is associated with complications and prolonged hospitalization. Cerebral small-vessel disease, a leading cause of dementia, is highly prevalent in elderly surgical patients. However, the relationship between cerebral small-vessel disease and postoperative delirium remains unknown. We therefore test the primary hypothesis that cerebral small-vessel disease is associated with postoperative delirium in elderly non-cardiac surgical patients. We prospectively evaluated patients 65 to 85 years old who had inpatient elective non-cardiac surgery at five academic centers in China. Independent neuroradiologists, masked to clinical data, quantified preoperative magnetic resonance markers of cerebral small-vessel disease, including lacune, white matter hyperintensity, perivascular space, cerebral microbleed, to estimate vascular abnormalities which were converted into a cerebral small-vessel disease burden score. Postoperative delirium was assessed twice daily during the initial 3 postoperative days using the Confusion Assessment Method for Intensive Care patients. Between July 8, 2020, and Sep 30, 2024, we enrolled 804 patients of whom 69 (9%) had a postoperative delirium. The risk of postoperative delirium progressively increased with higher cerebral small-vessel disease burden scores, reaching 28% in the most severely affected patients. Pre-existing high cerebral small-vessel disease burden was associated with an increased risk of postoperative delirium (adjusted odds ratio 1.95, 95% CI 1.15, 3.31, P=0.023). The attributable risk was estimated at 4.9% (95% CI 3.4%, 6.4%), with an estimated attributable risk percentage of 44% (95% CI 37%, 51%), indicating that nearly half of all postoperative delirium cases in this cohort were potentially attributable to pre-existing high cerebral small-vessel disease burden. Lacunes were especially associated with an increased risk of postoperative delirium (adjusted odds ratio 2.96, 95% CI 1.71, 5.10, P<0.001), as were white matter hyperintensities (adjusted odds ratio 3.32, 95% CI 1.97, 5.61, P<0.001). Pre-existing cerebral small-vessel disease burden measured by magnetic resonance imaging is associated with doubled odds of postoperative delirium in elderly non-cardiac surgical patients. Cerebral small-vessel disease thus appears to be a novel risk factor for postoperative delirium risk.