Neurologic complications remain a major cause of morbidity in patients undergoing surgical repair of acute type A aortic dissection (ATAAD). Near-infrared spectroscopy (NIRS) is used for continuous, noninvasive monitoring of cerebral oxygenation during cardiopulmonary bypass; however, its utility in predicting perioperative stroke remains inadequately defined. A retrospective cohort study was conducted in 175 patients who underwent ATAAD repair between 2015 and 2023. Patients were stratified by the occurrence of perioperative stroke (n = 47, 26.9%). Intraoperative NIRS data, including cerebral regional oxygen saturation (crSO₂) values at key procedural timepoints and signal variability with band power and crest factor, were analyzed in conjunction with demographic, anatomic, and postoperative variables. Patients with stroke exhibited significantly lower minimum NIRS values during deep hypothermic circulatory arrest (DHCA) (left: 46.7 (15.7–69.4) vs. 52.2 (22.0–81.6); right: 47.0 (23.3–78.5) vs. 56.3 (20.2–85.0); p = 0.03 and p < 0.01). Within the stroke group, NIRS signal variability was significantly greater (crest factor and standard deviation; p < 0.05) and showed blunted recovery post-DHCA. crSO₂ values below 50% were more frequent in the stroke group (p = 0.04). Right common carotid artery dissection was more prevalent in the stroke group (40% vs. 23%, p = 0.04). ICU length of stay was significantly increased in patients with stroke. Cerebral desaturation and NIRS signal instability during DHCA are significantly associated with perioperative stroke in ATAAD repair. These findings support the prognostic value of intraoperative cerebral oximetry in detecting critical ischemic thresholds and identifying at-risk perfusion patterns.

Background: Acute kidney injury (AKI) is common after acute type A aortic dissection (ATAAD) repair. We investigated whether intraoperative cerebral near-infrared spectroscopy (NIRS) was associated with postoperative AKI. Methods: This retrospective single-center study included 288 adults undergoing open repair of acute aortic dissection with hypothermic circulatory arrest between 2015 and 2023, predominantly for ATAAD, including seven non-A non-B dissections. Bilateral cerebral NIRS was recorded at five predefined time points. AKI was defined using modified creatinine/renal replacement therapy-based KDIGO criteria. Multivariable logistic regression included cardiopulmonary bypass (CPB) duration, DeBakey type I, and anatomical renal artery involvement; additional adjustment examined baseline NIRS. Results: AKI occurred in 181 patients (62.8%), including stage 3 in 94 (32.6%). Left-sided NIRS was lower with AKI before CPB (69% vs. 73%, p = 0.020) and five minutes before CPB completion (72% vs. 75%, p = 0.004). In multivariable analysis (n = 273), CPB duration (OR 1.016/minute, 95% CI 1.009–1.022, p < 0.001), renal artery involvement (OR 2.041 per additional artery, 95% CI 1.167–3.569, p = 0.012), and left-sided NIRS near CPB completion (OR 0.965/%, 95% CI 0.938–0.992, p = 0.011) were associated with AKI. The NIRS association attenuated after baseline adjustment (OR 0.976, 95% CI 0.946–1.006, p = 0.117). In-hospital mortality was higher with AKI (27.6% vs. 7.5%, p < 0.001). Conclusions: AKI affected nearly two thirds of patients undergoing ATAAD repair. Lower left-sided cerebral NIRS near CPB completion was associated with AKI after adjustment for bypass duration and renal artery involvement, but the association attenuated after baseline adjustment. This exploratory finding requires prospective validation.