Postoperative Neurological Dysfunction Research Articles

Intraoperative changes in electrophysiological monitoring can be used to predict clinical outcomes in patients with spinal cavernous malformation.

The study aimed to evaluate the sensitivity and specificity of these monitoring parameters in predicting postoperative neurological dysfunction. In this study, a total of 85 patients with spinal cavernous malformations (SCMs) treated at Xuanwu Hospital, Capital Medical University, from November 2012 to August 2017 were included. During the surgical procedures, all patients underwent monitoring of motor evoked potentials (MEP) and somatosensory evoked potentials (SEP). The criteria for warning included a reduction of ≥80% in MEP amplitude and ≥50% in SEP amplitude. Among 85 patients, 40 (47.1%) had SCMs located in the thoracic segment, 35 (41.2%) in the cervical segment, 6 (7.1%) in the cervical thoracic segment, and 4 (4.7%) in the lumbar segment. MEP recordings were obtained from 81 patients, and the preoperative McCormick score was 1.53 ± 0.69. The sensitivity of multimodal monitoring combined with the criteria of 80% reduction in MEP amplitude and SEP was 83.9%, with a specificity of 69%, a positive predictive value of 69%, and a negative predictive value of 90.4%. This study emphasizes the crucial role of electrophysiological monitoring, particularly MEP and SEP, during the surgical resection of SCMs. The findings demonstrate that this approach is effective in predicting and preventing postoperative neurological dysfunction, thereby improving patient outcomes.

Effects of temperature on transient neurologic dysfunction after total arch replacement.

The relationship between cooling status during aortic surgery with hypothermic circulatory arrest and postoperative neurologic dysfunction remains unknown. In the present study, we evaluated the effect of cooling status on transient neurologic dysfunction after total arch replacement. We studied patients who underwent elective total arch replacement with hypothermic circulatory arrest and antegrade selective cerebral perfusion from December 2011 to January 2021. Changes in tympanic temperature trends recorded during surgery were plotted. Several parameters, including the nadir temperature, cooling speed, and degree of cooling (cooling area, or the area under the curve of inverted temperature trends from cooling to rewarming as calculated by the integral method), were analyzed. The relationships between these variables and transient neurologic dysfunction were evaluated. Transient neurologic dysfunction was observed in 33 (14.5%) of the 228 included patients. In the transient neurologic dysfunction group, the cooling area was larger (2417.3 vs. 1920.8°Cmin; P < 0.001) and the cooling speed was higher (0.68 vs. 0.51°C/min; P < 0.001) than in the non-transient neurologic dysfunction group. A multivariate logistic model revealed that both the cooling area (odds ratio = 1.13 per 100°Cmin; P < 0.001) and cooling speed (odds ratio = 3.69 per °C/min; P = 0.041) were independent risk factors for transient neurologic dysfunction. Both the cooling area, which indicates the degree of cooling, and cooling speed had significant relationships with transient neurologic dysfunction after total arch replacement. Together, these findings indicate that overcooling and rapid cooling may contribute to brain injury.

Electrical impedance tomography provides information of brain injury during total aortic arch replacement through its correlation with relative difference of neurological biomarkers

Postoperative neurological dysfunction (PND) is one of the most common complications after a total aortic arch replacement (TAAR). Electrical impedance tomography (EIT) monitoring of cerebral hypoxia injury during TAAR is a promising technique for preventing the occurrence of PND. This study aimed to explore the feasibility of electrical impedance tomography (EIT) for warning of potential brain injury during total aortic arch replacement (TAAR) through building the correlation between EIT extracted parameters and variation of neurological biomarkers in serum. Patients with Stanford type A aortic dissection and requiring TAAR who were admitted between December 2021 to March 2022 were included. A 16-electrode EIT system was adopted to monitor each patient’s cerebral impedance intraoperatively. Five parameters of EIT signals regarding to the hypothermic circulatory arrest (HCA) period were extracted. Meanwhile, concentration of four neurological biomarkers in serum were measured regarding to time before and right after surgery, 12 h, 24 h and 48 h after surgery. The correlation between EIT parameters and variation of serum biomarkers were analyzed. A total of 57 TAAR patients were recruited. The correlation between EIT parameters and variation of biomarkers were stronger for patients with postoperative neurological dysfunction (PND(+)) than those without postoperative neurological dysfunction (PND(−)) in general. Particularly, variation of S100B after surgery had significantly moderate correlation with two parameters regarding to the difference of impedance between left and right brain which were MRAIabs and TRAIabs (0.500 and 0.485 with p < 0.05, respectively). In addition, significantly strong correlations were seen between variation of S100B at 24 h and the difference of average resistivity value before and after HCA phase (ΔARVHCA), the slope of electrical impedance during HCA (kHCA) and MRAIabs (0.758, 0.758 and 0.743 with p < 0.05, respectively) for patients with abnormal S100B level before surgery. Strong correlations were seen between variation of TAU after surgery and ΔARVHCA, kHCA and the time integral of electrical impedance for half flow of perfusion (TARVHP) (0.770, 0.794 and 0.818 with p < 0.01, respectively) for patients with abnormal TAU level before surgery. Another two significantly moderate correlations were found between TRAIabs and variation of GFAP at 12 h and 24 h (0.521 and 0.521 with p < 0.05, respectively) for patients with a normal GFAP serum level before surgery. The correlations between EIT parameters and serum level of neurological biomarkers were significant in patients with PND, especially for MRAIabs and TRAIabs, indicating that EIT may become a powerful assistant for providing a real-time warning of brain injury during TAAR from physiological perspective and useful guidance for intensive care units.

Application of neurophysiological monitoring during tethered cord release in children

ObjectiveThe objective of this study was to explore the effect of intraoperative neurophysiological monitoring (IONM) on tethered spinal cord release in children.MethodsThe clinical data of 454 children with tethered cord syndrome who underwent surgery for tethered cord release were retrospectively analyzed. The children were divided into two groups: the non-IONM group and the IONM group. SPSS 26.0 software was used for statistical analysis. The evaluation indices included the effective rate and incidence of new neurological dysfunction.ResultsThe short-term results showed that the effective rate of the non-IONM group was 14.8%, while that of the IONM group was 15.2%. Additionally, the incidence of new neurological dysfunction was 7.8% in the non-IONM group and 5.6% in the IONM group. However, there was no significant difference between the two groups (P > 0.05). The medium- to long-term follow-up had significant difference (P < 0.05), the response rate was 32.1% in the IONM group and 23.7% in the non-IONM group, and deterioration rates regarding neurological dysfunction were 3.3% in the IONM group and 8.5% in the non-IONM group.ConclusionThis study revealed that the use of IONM does not significantly improve the short-term treatment effect of patients undergoing surgery for tethered cord release or reduce the short-term incidence of postoperative new neurological dysfunction. However, the medium- to long-term prognoses of patients in the IONM group were better than those of patients in the non-IONM group.

Is axillary artery cannulation necessary in type II hybrid aortic arch repair for acute type A aortic dissection?

Axillary artery cannulation (AAC) has been widely employed in total arch replacement surgeries using the frozen elephant trunk (FET) technique for acute type A aortic dissection (ATAAD), showing better clinical results than femoral artery cannulation (FAC). Nevertheless, in type II hybrid arch repair (HAR), FAC is crucial for lower body perfusion. Hence, it is unclear whether AAC remains necessary or if AAC represents a more advantageous method for initiating cardiopulmonary bypass. We conducted a study involving patients diagnosed with ATAAD who underwent type II HAR from August 2021 to December 2022. Demographic baseline and intraoperative data were collected, and the postoperative outcomes of patients receiving FAC only were compared with those receiving AAC. There were no significant differences in baseline demographics between patients who underwent FAC alone (n = 46) and those who underwent AAC (n = 39). Patients who underwent AAC showed a lower incidence of transient neurological dysfunction (TND) post-surgery compared to those who underwent FAC (12.8% vs 32.6%, p = .032). There were no significant differences between the groups in terms of postoperative mortality within 30days, permanent neurological dysfunction (PND), length of stay in the intensive care unit (ICU) and postoperative ward, duration of mechanical ventilation, and other complications. Axillary artery cannulation may decrease the incidence of postoperative transient neurological dysfunction (TND) in type II HAR for ATAAD. Nonetheless, studies with larger sample sizes are necessary.

A nomogram-based model to predict postoperative transient neurological dysfunctions in patients receiving acute type A aortic dissection surgery.

The purposes of this study were to develop and validate a nomogram for predicting postoperative transient neurological dysfunctions (TND) in patients with acute type A aortic dissection (AAAD) who underwent modified triple-branched stent graft implantation. This retrospective study developed a nomogram-based model in a consecutive cohort of 146 patients. Patient characteristics, preoperative clinical indices, and operative data were analyzed. Univariate and multivariable analyses were applied to identify the most useful predictive variables for constructing the nomogram. Discrimination and the calibrationof the model was evaluated through the receiver operating characteristic curve (ROC), the Hosmer-Lemeshow goodness-of-fit test and the decision curve analysis (DCA). At the same time, to identify and compare long-term cumulative survival rate, Kaplan-Meier survival curve was plotted. The incidence rate of postoperative TND observed in our cohort were 40.9%. Supra-aortic dissection with or without thrombosis, creatinine >115μmol and albumin <39.7g/L, selective antegrade cerebral perfusion (SACP) time >7min and total operation time >303min, were confirmed as independent predictors that enhanced the likelihood of TND. Internal validation showed good discrimination of the model with under the ROC curve (AUC) of 0.818 and good calibration (Hosmer-Lemeshow test, p>.05). DCA revealed that the nomogram was clinically useful. In the long-term survival there was no significant difference between patients with or without TND history. The results showed the predict model based on readily available predictors has sufficient validity to identify TND risk in this population, that maybe useful for clinical decision-making.

Effectiveness of MEP and SSEP Monitoring in the Diagnosis of Neurological Dysfunction Immediately After Craniotomy Aneurysm Clipping.

To explore the diagnostic accuracy of motor-evoked potential (MEP) and somatosensory-evoked potential (SSEP) monitoring in predicting immediate neurological dysfunction after craniotomy aneurysm clipping. A total of 184 patients with neurosurgery aneurysms in the Affiliated Hospital of Qingdao University from April 2019 to December 2021 were retrospectively included. All patients underwent craniotomy aneurysm clipping, and MEP and SSEP were used to monitor during the operation. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff value for early warning of MEP and SSEP amplitude decline and to evaluate the effectiveness of MEP and SSEP changes in predicting immediate postoperative neurological dysfunction. Among the 184 patients with intracranial aneurysms, the incidences of immediate postoperative neurological dysfunction were 44.4% (12/27) and 3.2% (5/157) in patients with intraoperative MEP changes and without changes, respectively. For SSEP, The incidence rates were 52.6% (10/19) and 4.2% (7/165), respectively, and the differences were statistically significant ( P <0.001). Significant changes in intraoperative MEP and SSEP were significantly associated with the development of immediate postoperative neurological deficits ( P <0.05). The critical values for early warning of MEP and SSEP amplitude decrease were: 61.6% ( P < 0.001, area under the curve 0.803) for MEP amplitude decrease and 54.6% ( P <0.001, area under the curve 0.770) for SSEP amplitude decrease. The sensitivity and specificity of MEP amplitude change in predicting immediate postoperative neurological dysfunction were 70.6% and 91.0%, respectively. For SSEP amplitude changes, the sensitivity and specificity were 58.8% and 95.8%, respectively. Motor-evoked potential and SSEP monitoring have moderate sensitivity and high specificity for immediate postoperative neurological dysfunction after craniotomy aneurysm clipping. Motor-evoked potential is more accurate than SSEP. Patients with changes in MEP and SSEP are at greatly increased risk of immediate postoperative neurologic deficits.

Effects of Remote Ischemic Preconditioning on Delirium and Neurological Function in Patients Undergoing Cardiac Surgery: A Multicenter Randomized Controlled Trial.

Postoperative delirium (POD) and neurological dysfunction are very common following cardiac surgery and deteriorate the patient's prognosis and the outcome of surgical procedures. A clinically effective management strategy or drug is not yet available for POD. Additionally, it is unknown whether remote ischemic preconditioning (RIPC) has neuroprotective and anti-delirium benefits in patients who undergo cardiac surgery. This study examined whether RIPC can improve POD and neurological function in cardiac surgery patients. We screened 510 consecutive adult patients aged 18 and older who underwent cardiac surgery between January 2018 and December 2022. Then, 448 of these patients were recruited in the trial as the intention to treat (ITT) group, who were then randomly assigned to receive either a control (n = 223) or RIPC treatment (n = 225). The primary outcome measures were hospitalization postoperative delirium, six-month modified Rankins scale (mRS), hospital cerebral infarction, 30-day overall mortality, neuron-specific enolase (NSE) and S-100b levels, related adverse effects, hospital costs, and hospital stay. A statistically significant variation was not observed between the two groups in terms of the baseline clinical data. In contrast to the control group, the POD in the RIPC group was considerably alleviated. RIPC treatment also decreased the levels of NSE and S-100b, which alleviated nerve injury. The adverse impacts of RIPC-induced objective indicators of tissue or neurovascular damage were similar in both groups, showing no significant variations between the two. The hospital stays and hospitalization costs also decreased significantly in the RIPC-treated patients. The study findings suggested that RIPC may benefit cardiac surgery patients by reducing POD, alleviating injury, and lowering hospital expenditures and length of stay. Cardiac surgery patients can be treated with RIPC, which is an effective and safe technique.

Impact of multimodal intraoperative neurophysiological monitoring of the spinal cord during spine and spinal cord surgeries

BackgroundThere is growing evidence of the valuable role of multimodal intraoperative neurophysiological monitoring (IONM) during spine and spinal cord surgeries, as it provides an opportunity to recognize functional changes of the neural elements, usually in the reversible stage, during complex surgical manipulations. Therefore, it may reduce the risk of postoperative neurological dysfunction and improve functional outcomes. The aim of the current study was to evaluate the efficacy of multimodal IONM for preventing and predicting iatrogenic neurological dysfunction during spinal cord and spine surgeries.ResultsSignificant alerts had occurred in 9 out of 24 patients; however, all the changes were reversible and did not contribute to postoperative clinical deterioration. Only one case got worsened in the early postoperative follow-up period, with stable intraoperative monitoring.ConclusionIntraoperative monitoring is a valuable tool in spine and spinal cord surgeries. Combined transcranial motor-evoked potential (TcMEP), somatosensory-evoked potential (SSEP), and spontaneous electromyography (EMG) monitoring may prevent permanent motor deficit and enhance the postoperative outcomes.

Extra-anatomic revascularization and a new cannulation strategy for preoperative cerebral malperfusion due to severe stenosis or occlusion of supra-aortic branch vessels in acute type A aortic dissection

ObjectivesAcute type A aortic dissection (ATAAD) with severe stenosis or occlusion of the true lumen of aortic arch branch vessels often leads to an increased incidence of severe postsurgical neurological complications and mortality rate. In this study, we aimed to introduce our institutional extra-anatomic revascularization and cannulation strategy with improved postoperative outcomes for better management of patients with cerebral malperfusion in the setting of ATAAD. MethodsTwenty-eight patients with ATAAD complicated by severe stenosis or occlusion of the aortic arch branch vessels, as noted on combined computed tomography angiography of the aorta and craniocervical artery, between January 2021 and June 2022 were included in this study. Basic patient characteristics, surgical procedures, hospitalization stays, and early follow-up results were analyzed. ResultsThe median follow-up duration was 16.5 months (interquartile range: 11.5–20.5), with a 100% completion rate. The 30-day mortality rates was 7.1% (2/28 patients); two patients had multiple cerebral infarctions on preoperative computed tomography and persistent coma. Postoperative transient neurological dysfunction occurred in 10.7% (3/28) of the patients, and no new permanent neurological dysfunction occurred. Of all the patients, 3.6% (1/28) had novel acute renal failure. No other deaths, secondary surgeries, or serious complications occurred during the early follow-up period. ConclusionsUse of extra-anatomic revascularization and a new cannulation strategy before cardiopulmonary bypass is safe and feasible and may reduce the high incidence of postoperative neurological complications in patients with ATAAD and cerebral malperfusion.

Apolipoprotein E4 allele is genetically associated with risk of the short- and medium-term postoperative cognitive dysfunction: A meta-analysis and trial sequential analysis.

The aim of systematic review and meta-analysis was to investigate whether APOE4 was associated with postoperative neurologic dysfunction occurrence in short- or medium-term among surgical patients and to study the potential genetic association among these two entities. We searched electronic databases for reserch studies to evaluate the association of APOE4 with postoperative delirium (POD) or short- and medium term postoperative cognitive dysfunction (POCD). Twenty-two trials (16 prospective and six retrospective) with 6734 patients were included. APOE4 alleles was shown significantly associated with POCD within 1 week (odds ratio, OR, 1.89, 95% confidence interval, CI, 1.36 to 2.6278, p < 0.01) in the random-effects model. A significant association was also noted between APOE4 and POCD in medium-term, 1-3 months, after surgery (OR: 1.67, 95% CI: 1.003-2.839, p = 0.049). However, APOE4 was not significantly associated with POCD 1 year after surgery (OR: 0.98, 95% CI: 0.57-1.70, p = 0.9449) and POD (OR: 1.28, 95% CI: 0.85-1.91, p = 0.23). In conclusion, APOE4 alleles was genetically associated with short- and medium-term postoperative neurological dysfunction and future screening or preventive strategies derived is highly potential to improve outcomes.

Application of Intraoperative Electromyography Intelligent Monitoring in Orthopedic Surgery under General Anesthesia.

To study the application of intraoperative EMG intelligent monitoring in orthopedic surgery under general anesthesia, a total of 53 patients who underwent orthopedic surgery from February 2021 to February 2022 were selected. The combined monitoring of somatosensory evoked potential (SEP), motor evoked potential (MEP), and electromyography (EMG) was used to analyze the monitoring efficiency. In 38 of the 53 patients, the intraoperative signal was normal, and there was no postoperative neurological dysfunction; one case had abnormal signal, and the abnormality still existed after debugging, but no obvious neurological dysfunction was found after operation; the remaining 14 cases had abnormal signal. There were 13 early warnings in SEP monitoring; 12 early warnings in MEP monitoring; 10 early warnings in EMG monitoring. There were 15 cases of early warning in the joint monitoring of the three, and the sensitivity of the combined monitoring of SEP + MEP + EMG was significantly higher than that of the single monitoring of SEP, MEP, and EMG (p < 0.05). There was no significant difference in specificity, positive predictive value, and negative predictive value between combined monitoring and single monitoring (p > 0.05). The combined monitoring of EMG, MEP, and SEP in orthopedic surgery can significantly improve the safety of surgery, its sensitivity and negative predictive value were significantly higher than the monitoring effects of the two alone.

Predictive value of neurophysiological monitoring during posterior communicating artery aneurysm clipping for postoperative neurological deficits.

This study aimed to evaluate the diagnostic effect of intraoperative neurophysiological monitoring in identifying intraoperative ischemic events and predicting postoperative neurological dysfunction during PCoA aneurysm clipping, as well as to explore the safe duration of intraoperative temporary clipping of the parent artery. All 71 patients with PCoA aneurysm underwent craniotomy and aneurysm clipping. MEP and SSEP were used for monitoring during operation to evaluate the influence of MEP/SSEP changes on postoperative neurological function. Receiver operating characteristic (ROC) curve analysis was used to calculate optimal duration of intraoperative temporary clipping. Patients with intraoperative MEP/SSEP changes were more likely to develop short-term and long-term neurological deficits than those without MEP/SSEP changes (P < 0.05). From the ROC curve analysis, the safe time from the initiation of temporary clipping during the operation to the early warning of neurophysiological monitoring was 4.5 min (AUC = 0.735, 95%CI 0.5558-0.912). Taking 4.5 min as the dividing line, the incidence of short-term and long-term neurological dysfunction in patients with temporary clipping >4.5 min was significantly higher than that in patients with temporary clipping ≤4.5 min (P = 0.015, P = 0.018). Intraoperative MEP/SSEP changes are significantly associated with postoperative neurological dysfunction in patients with PCoA aneurysms. The optimal duration of temporary clipping of the parent artery during posterior communicating aneurysm clipping was 4.5 min under neurophysiological monitoring.

Monitoring of regional cerebral oximetry by near-infrared spectroscopy during off-pump coronary artery bypass grafting to evaluate the impact on postoperative neurocognitive dysfunction – A prospective study

Abstract Background and Aims: Postoperative neurological dysfunction is a common noncardiac complication following cardiac surgery. Primary objective of our study was to evaluate the effects of cerebral oxygen desaturation on the neurological outcome in the postoperative period by monitoring regional cerebral oxygen saturation in off-pump coronary artery bypass grafting (OPCABG). Secondary objective was to study the correlation between regional cerebral oxygen saturation and mean arterial pressure (MAP) during grafting. Setting and Design: It was a prospective observational study in 100 patients of the American Society of Anesthesiologists physical status grading II-III of either sex, having triple vessel coronary artery disease undergoing OPCABG. Patient, having left ventricular ejection fraction (LVEF) &lt;35%, carotid artery disease, on extracorporeal membrane oxygenator or intra-aortic balloon pump, preexisting neurological disorder with standardized mini-mental state examination (SMMSE) score &lt;23, undergoing emergency surgery, re-do surgery, and co-existing valvular diseases were excluded from the study. Surgeries were conducted under general anesthesia with midazolam 0.1 mg/kg, fentanyl 5 μg/kg, and vecuronium 0.1 mg/kg. Anesthesia was maintained with intermittent boluses of fentanyl, vecuronium, and isoflurane. Materials and Methods: The SMMSE was performed preoperatively, 8 and 12 h after extubation. Patients with postoperative SMMSE score of 24–30 were allocated to Group A and patients with SMMSE score ≤ 23, were allocated to Group B. The cerebral oxygen saturation (rSO2), heart rate, MAP, and arterial blood gas were monitored perioperatively. Statistical Analysis: The Chi-square test was used to compare categorical variables and independent Samples t-test was used to compare continuous variables. Pearson bivariate correlation test was used to correlate between the continuous variables. Results: The mean difference of right and left rSo2, between baseline value, and during saphenous vein graft (SVG) to obtuse marginal grafting were 8.70 ± 3.38, 8.78 ± 3.19 in group A and 18.8 ± 2.40, 18.91 ± 1.88, respectively, in group B and were found to be statistically significant. The mean difference of right and left rSO2, between baseline value and during SVG to posterior descending artery grafting were 6.48 ± 3.91, 7.10 ± 3.67 in group A and 18.1 ± 3.57, 17.9 ± 3.60 in group B and were found to be statistically significant. Mean difference and percentage variation from baseline of right and left rSo2 and MAP from preinduction to grafting from left internal mammary artery to left anterior descending artery were found to be statistically insignificant. Conclusion: A decrease of regional cerebral saturation value by 25% from baseline or an absolute reduction of rSO2 value by 50% and reduction in MAP from baseline, during the period of grafting was associated with postoperative neurocognitive dysfunction.

Clinical application of 3D Slicer combined with Sina/MosoCam multimodal system in preoperative planning of brain lesions surgery

To explore the clinical advantages of 3D Slicer combined with Sina/MosoCam multimodal system in preoperative planning of brain lesions surgery. By collecting the data of brain lesions patients undergoing craniotomy under the preoperative positioning of 3D Slicer combined Sina/MosoCam multimodal system in the people's Hospital of Wuhan University from January 2021 to October 2021, the preoperative planning of patients was introduced, and the size of surgical bone window, operation time, preoperative and postoperative neurological dysfunction were counted. We collected the case data of 35 patients who were reconstructed by 3D Slicer and located by Sina/MosoCam projection. There were 14 cases of malignant tumors (7 cases of glioma, 2 cases of diffuse large B-cell lymphoma, 5 cases of metastatic cancer) and 21 cases of benign tumors (17 cases of meningioma, 1 case of central neurocytoma, 2 cases of cavernous hemangioma and 1 case of arachnoid cyst). All 35 patients were located accurately before operation, the lesions were found quickly during operation, and the postoperative imaging data confirmed that the lesions were removed completely, of which 28 cases (80%) had significantly improved neurological symptoms one month after operation. 3D Slicer combined with Sina/MosoCam multimodal system has many advantages, such as simple and easy to learn, convenient operation, accurate positioning and free. It is considered to be a new technology that is practical, reliable, convenient for diagnosis and preoperative planning. It is suitable for popularization and use in neurosurgery and other operating rooms of all medical institutions.

O107 / #726 MIDLINE ISOLATION AND NEUROMONITORING WITH HIGH-DENSITY MICROELECTRODE ARRAYS FROM THE SURFACE OF THE SPINAL CORD: TRACK 4: CARDIOVASCULAR DISORDERS / NEURAL ENGINEERING

Intraoperative neuromonitoring (IONM) reduces the risk for postoperative neurological dysfunction during spinal cord surgery (1–4). Common IONM techniques do not record directly from the spinal cord, but instead rely on indirect measures, including evoked motor and sensory potentials. However, the exposed cord provides an untapped potential for direct assessment of function and pathology. Direct recordings from the spinal cord could lower the amount of stimulation required to capture responses and allow for continual monitoring (5–7). Here, we present results from human spinal cord recordings using highly conformable microelectrode arrays with high-density spatial coverage. Future clinical application of this technology would include treatment of spinal cord injury (SCI) and chronic pain.

Elective aortic arch surgery: cerebral perfusion flows and transient neurological dysfunctions.

Selective antegrade cerebral perfusion technique is a method of cerebral protection used worldwide during aortic arch surgery. This study was designed to identify a potential correlation between perfusion flows and the development of postoperative transient neurological dysfunctions. From January 2015 to May 2020, 175 patients underwent elective surgical replacement of the aortic arch using selective antegrade cerebral perfusion at the Cardiac Surgery Unit of Sant'Orsola Hospital in Bologna. Considering that patients who developed a permanent neurological dysfunction and those who died before a possible evaluation of neurological status were excluded, the study population included 160 patients. The perfusion flows were collected and analyzed. Univariate and multivariate analyses were performed to identify the statistical risk factors involved in the onset of transient neurological dysfunctions. The study population was divided into two groups: 138 patients (86.3%) without and 22 (13.8%) with postoperative transient neurological complications. Among the intra-operative parameters collected in the study, the univariate analysis showed that the indexed medium perfusion flow of selective antegrade cerebral perfusion was significantly lower in the transient neurological dysfunctions group (11.63 ± 2.41 ml/kg/min vs 12.62 ± 2.39 ml/kg/min, P -value = 0.03). The multivariate logistic regression analysis showed that the female gender ( P = 0.004, OR = 4.816, IC = 1.636-14.174) was predictor of transient neurological dysfunctions. The results of the study showed that lower perfusion flows seem to be related to a higher probability of developing transient neurological dysfunctions. However, the analysis of a wider population is required to confirm these preliminary data.

Application of retrograde cerebral perfusion in aortic root replacement combined with right half aortic arch replacement.

After cardiac surgery involving the aortic arch, the incidence of neurological complications remains high, therefore it is very important to take measures to protect brain. This study is to investigate the safety and effectiveness of deep hypothermic circulatory arrest and retrograde cerebral perfusion for aortic root combined with right half aortic arch replacement. Clinical data of 31 patients, who underwent aortic root and right half aortic arch replacement with deep hypothermic circulatory arrest and retrograde cerebral perfusion in Xiangya Hospital, Central South University, were retrospectively analyzed. This cohort included 23 aortic aneurysms and 8 aortic dissections. Aortic root replacement was conducted in 26 patients by Bentall procedures, and 5 patients by David procedures. Time of deep hypothermic circulatory arrest and retrograde cerebral perfusion in surgery was (21.9±5.2) min. The in-hospital mortality, postoperative neurological dysfunction and other major adverse complications were observed and recorded. No in-hospital death and permanent neurological dysfunction occurred. Two patients had transient neurological dysfunction and 2 patients with aortic dissection requiring long-time ventilation due to hypoxemia, 1 patient underwent resternotomy. During 6-36 months of follow-up, all patients recovered satisfactorily. Deep hypothermic circulatory arrest and retrograde cerebral perfusion can be safely and effectively applied in aortic root and right half aortic arch replacement, and which can simplify the surgical procedures and be worth of clinical promotion.

Can regional cerebral oxygen saturation monitoring during circulatory arrest time predict postoperative neurological dysfunction in patients undergoing surgical pulmonary thromboendarterectomy? Useful index for short- and long-term outcomes.

A hypothermic circulatory arrest is usually used to correct thoracic aorta pathologies. The emergency treatment of acute type A aortic dissection and elective repair of aortic arch pathologies are the most common indications for using hypothermic circulatory arrest. A hypothermic circulatory arrest can also be used for surgical pulmonary thromboendarterectomy in patients with chronic thromboembolic pulmonary hypertension. Intervals with total circulatory arrest offer a clear surgical field for thrombus and emboli removal from the pulmonary artery branches. The price to pay for intermittent circulatory arrest during pulmonary thromboendarterectomy is postoperative neurological dysfunction due to brain hypothermia and hypoperfusion. A noninvasive method for cerebral monitoring during cardiac surgery is real-time regional cerebral oxygen saturation (rSO2 ). Liu et al. report that continuous monitoring of rSO2 during surgical pulmonary thromboendarterectomy may reduce the long cerebral hypoperfusion time and prevent postoperative neurological dysfunction.

Impact of supra-aortic vessel dissection on the neurological outcome in surgery for acute type A aortic dissection.

We investigated whether supra-aortic vessel (SAV)s dissection is a risk factor for neurological dysfunction (ND) after surgical repair for type A acute aortic dissection (TAAAD). A retrospective review was done in 178 patients with TAAAD undergoing aortic repair between 2015 and 2019, comparing those with SAV dissection to those without it. Preoperatively, 93 patients (54.4%) had SAV dissection. Postoperatively, ND occurred in 26 patients (14.6%), 17 of whom (65.4%) already had been present with preoperative ND. Patients with SAV dissection were more likely to have postoperative ND than those without it (21.5% vs 7.7%; p = 0.02). The severity of preoperative dissection-related stenosis in common carotid artery significantly related to postoperative ND (right; p =0.0071, left; p < 0.0001). Multivariable analysis showed dissection-related stenosis of > 75% in brachiocepharic and left common carotid arteries, and thrombosed false lumen in common carotid arteries were independent risk factors for postoperative ND. However, SAV dissection was not related to new onset of ND. Dissection with stenosis of > 75% in SAVs were significantly decreased after aortic repair and even after ascending aorta/hemiarch replacement. In conclusion, ND after surgical repair for TAAAD is closely related to SAV dissection, especially to stenosis of > 75% and thrombosed false lumen in common carotid arteries. Aortic repair significantly decreased SAV dissection and severity of stenosis.