Surgery May Be a Major Contributor for Postoperative Delirium in Patients With Elective Thoracic Aortic Aneurysm Procedures.

AIMS: Postoperative delirium (POD) is relatively common and is associated with poor outcomes. Age is a risk factor for POD. This single-center observational study is designed to determine whether surgery is a major contributor to the development of POD and inflammatory response. METHODS: Patients with elective procedures to repair thoracic aortic aneurysm were recruited to the study. Confusion Assessment Method was used to assess POD. Their blood and cerebrospinal fluids were harvested for analysis of inflammatory and neuronal injury indicators. RESULTS: A total of 67 patients were included in this study: 32 had stent placement under general anesthesia and 35 had open surgery to repair the aneurysm. No patients in the stent placement group had POD, but 9 patients in the open surgery group had POD (25.7%). Patients with POD had a lower body temperature at the end of surgery than patients without POD [36.3°C (35.7°C-36.6°C) vs. 36.7°C (36.3°C-37.0°C), p = 0.046]. This parameter was identified as a risk factor for POD. Patients in the open surgery group had increased interleukin 1β and neurofilament light chain in the blood. However, there was no change in these biomarkers in the cerebrospinal fluids at 10 and 24 h after surgery. CONCLUSION: Our results suggest that surgery is a major contributor to POD, inflammatory response, and neuronal injury. Low body temperature at the end of surgery is a potential risk factor for POD in patients with open repair for thoracic aortic aneurysm.