Cerebral Small-vessel Disease and Postoperative Delirium in Elderly Noncardiac Surgical Patients

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. The authors therefore tested the primary hypothesis that cerebral small-vessel disease is associated with postoperative delirium in elderly noncardiac surgical patients.

The authors prospectively evaluated patients 65 to 85 yr old who had inpatient elective noncardiac 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, and 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 Unit.

Between July 8, 2020, and Sep 30, 2024, the authors enrolled 804 patients, of whom 69 (9%) had 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. Preexisting high cerebral small-vessel disease burden was associated with an increased risk of postoperative delirium (adjusted odds ratio, 1.95; 95% CI, 1.15 to 3.31; P = 0.023). The attributable risk was estimated at 4.9% (95% CI, 3.4% to 6.4%), with an estimated attributable risk percentage of 44% (95% CI, 37% to 51%), indicating that nearly half of all postoperative delirium cases in this cohort were potentially attributable to preexisting 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 to 5.10; P < 0.001), as were white matter hyperintensities (adjusted odds ratio, 3.32; 95% CI, 1.97 to 5.61; P < 0.001).

Preexisting cerebral small-vessel disease burden measured by magnetic resonance imaging is associated with doubled odds of postoperative delirium in elderly noncardiac surgical patients. Cerebral small-vessel disease thus appears to be a novel risk factor for postoperative delirium risk.