Cerebrovascular Disease and Perioperative Neurologic Vulnerability: A Prospective Cohort Study

Abstract

Background: Stroke is a devastating perioperative complication without effective methods for prevention or diagnosis. The objective of this study was to analyze evidence-based strategies for detecting cerebrovascular vulnerability and injury in a high-risk cohort of non-cardiac surgery patients. Methods: This was a single-center, prospective cohort study. Fifty patients undergoing non-cardiac surgery were recruited −25 with known cerebrovascular disease and 25 matched controls. Neurologic vulnerability was measured with intraoperative cerebral oximetry as the primary outcome. Perioperative neurocognitive testing and serum biomarker analysis (S-100β, neuron specific enolase, glial fibrillary acid protein, and matrix metalloproteinase-9) were measured as secondary outcomes. Results: Cerebral desaturation events (an oximetry decrease ≥20% from baseline or <50% absolute value for ≥3 min) occurred in 7/24 (29%) cerebrovascular disease patients and 2/24 (8.3%) controls (relative risk 3.5, 95% CI 0.81–15.2; P = 0.094). Cognitive function trends were similar in both groups, though overall scores (range: 1,500–7,197) were ~1 standard deviation lower in cerebrovascular patients across the entire perioperative period (−1,049 [95% CI −1,662, −436], P < 0.001). No significant serum biomarker differences were found between groups over time. One control patient experienced intraoperative hypoxic-ischemic injury, but no robust biomarker or oximetry changes were observed. Conclusions: Cerebrovascular disease patients did not demonstrate dramatic differences in cerebral oximetry, cognitive trajectory, or molecular biomarkers compared to controls. Moreover, a catastrophic hypoxic-ischemic event was neither predicted nor detected by any strategy tested. These findings support the need for novel research into cerebrovascular risk and vulnerability.

Stroke in Surgical Patients

“…A recent prospective cohort study of noncardiac surgery patients revealed that modified National Institutes of Health (Bethesda, Maryland) stroke scale changes were common postoperatively. 71 Increased scores, compared with preoperative baseline, were found in 20% of low-risk patients and more than 30% of high-risk patients. Such tools may thus have a low positive predictive value in the immediate postoperative setting.…”

“…However, currently, there are no clinically validated, reliable biomarkers for detecting cerebral ischemia and infarction. 71 Thus, currently available clinical screening tools and serum biomarkers are not presently recommended for routine postoperative screening. A targeted examination that focuses on signs and symptoms of large-vessel occlusion (table 3) may improve stroke detection.…”

“…Current clinical assessment tools and serum biomarkers do not appear to have high specificity in the perioperative setting. 71 Neurophysiologic methods (e.g., electroencephalography, transcranial Doppler, bioimpedance) could be tested for detecting cerebrovascular vulnerability postoperatively. Last, a perioperative stroke registry could be created to curate granular detail on preoperative risk factors, surgical subtypes, intraoperative physiology and events, postoperative management, reported etiologies, and long-term trajectory.…”

Correlation between brain tissue oxygen tension and regional cerebral oximetry in uninjured human brain under conditions of changing ventilation strategy

“…The absolute value of rSO 2 is difficult to interpret without context. Indeed, we have reported catastrophic ischemic neurological injury without noteworthy perturbation in cerebral oximetry values [15] and, despite meta-analysis, the effect of perioperative NIRS monitoring of the brain remains uncertain [16]. Trend monitoring has been previously suggested as the most appropriate application for cerebral oximetry [3]; our data support no more than this use.…”

Effect of low vs high haemoglobin transfusion trigger on cardiac output in patients undergoing elective vascular surgery: Post‐hoc analysis of a randomized trial

“…That animal model corroborates the present findings and suggests that haemodiluting Hb below 7‐8 g/dL is too large to maintain cerebral oxygenation although increased arterio‐venous O 2 ‐extraction may secure cerebral oxygen consumption. Carotid atherosclerosis is seen in 20%‐30% of vascular surgical patients 1,4 and may reduce brain perfusion pressure, the capacity to increase oxygen extraction, and impair cerebral autoregulation 24 . Cerebral perfusion is sensitive to changes in MAP 25 but MAP was identical in the two groups.…”