Role of Intraoperative Neuromonitoring to Predict Postoperative Delirium in Cardiovascular Surgery.

OBJECTIVE: Postoperative delirium (POD) can occur in up to 50% of older patients undergoing cardiovascular surgery, resulting in hospitalization and significant morbidity and mortality. This study aimed to determine whether intraoperative neurophysiologic monitoring (IONM) modalities can be used to predict delirium in patients undergoing cardiovascular surgery. DESIGN: Adult patients undergoing cardiovascular surgery with IONM between 2019 and 2021 were reviewed retrospectively. Delirium was assessed multiple times using the Intensive Care Delirium Screening Checklist (ICDSC). Patients with an ICDSC score ≥4 were considered to have POD. Significant IONM changes were evaluated based on a visual review of electroencephalography (EEG) and somatosensory evoked potentials data and documentation of significant changes during surgery. SETTING: University of Pittsburgh Medical Center hospitals. PARTICIPANTS: Patients 18 years old and older undergoing cardiovascular surgery with IONM monitoring. MEASUREMENTS AND MAIN RESULTS: Of the 578 patients undergoing cardiovascular surgery with IONM, 126 had POD (21.8%). Significant IONM changes were noted in 134 patients, of whom 49 patients had delirium (36.6%). In contrast, 444 patients had no IONM changes during surgery, of whom 77 (17.3%) patients had POD. Upon multivariate analysis, IONM changes were associated with POD (odds ratio 2.12; 95% CI 1.31-3.44; p < 0.001). Additionally, baseline EEG abnormalities were associated with POD (p = 0.002). CONCLUSION: Significant IONM changes are associated with an increased risk of POD in patients undergoing cardiovascular surgery. These findings offer a basis for future research and analysis of EEG and somatosensory evoked potential monitoring to predict, detect, and prevent POD.

Diagnostic utility of different types of somatosensory evoked potential changes in pediatric idiopathic scoliosis correction surgery.

PURPOSE: To evaluate the diagnostic accuracy of intraoperative somatosensory evoked potential (SSEP) monitoring and types of SSEP changes in predicting the risk of postoperative neurological outcomes during correction surgery for idiopathic scoliosis (IS) in the pediatric age group (≤ 21 years). METHODS: Database review was performed to identify literature on pediatric patients with IS who underwent correction with intraoperative neuromonitoring. The sensitivity, specificity, and diagnostic odds ratio (DOR) of transient and persistent SSEP changes and complete SSEP loss in predicting postoperative neurological deficits were calculated. RESULTS: Final analysis included 3778 patients. SSEP changes had a sensitivity of 72.9%, specificity of 96.8%, and DOR of 102.3, while SSEP loss had a sensitivity of 41.8%, specificity of 99.3%, and DOR of 133.2 for predicting new neurologic deficits. Transient and persistent SSEP changes had specificities of 96.8% and 99.1%, and DORs of 16.6 and 59, respectively. CONCLUSION: Intraoperative SSEP monitoring can predict perioperative neurological injury and improve surgical outcomes in pediatric scoliosis fusion surgery. LEVEL OF EVIDENCE: Level 2. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Cost-benefit analysis of intraoperative neuromonitoring for cardiac surgery.

BACKGROUND: Intraoperative neuromonitoring (IONM) can detect large vessel occlusion (LVO) in real-time during surgery. The aim of this study was to conduct a cost-benefit analysis of utilizing IONM among patients undergoing cardiac surgery. METHODS: A decision-analysis tree with terminal Markov nodes was constructed to model functional outcome, as measured via the modified Rankin Scale (mRS), among 65-year-old patients undergoing cardiac surgery. Our cost-benefit analysis compares the use of IONM (electroencephalography and somatosensory evoked potential) against no IONM in preventing neurological complications from perioperative LVO during cardiac surgery. The study was performed over a lifetime horizon from a societal perspective in the United States. Base case and one-way probabilistic sensitivity analyses were performed. RESULTS: At a baseline LVO rate of 0.31%, the mean attributable lifetime expenditure for IONM-monitored cardiac surgeries relative to unmonitored cardiac surgeries was $1047.41 (95% CI, $742.12 - $1445.10). At a critical LVO rate of approximately 3.67%, the costs of both monitored and unmonitored cardiac surgeries were the same. Above this critical rate, implementing IONM became cost-saving. On one-way sensitivity analysis, variation in LVO rate from 0% - 10% caused lifetime costs attributable to receiving IONM to range from $1150.47 - $29404.61; variations in IONM cost, percentage of intervenable LVOs, IONM sensitivity, and mechanical thrombectomy cost exerted comparably minimal influence over lifetime costs. DISCUSSION: We find considerable cost savings favoring the use of IONM under certain parameters corresponding to high-risk patients. This study will provide financial perspective to policymakers, clinicians, and patients alike on the appropriate use of IONM during cardiac surgery.

Utility of transcranial motor-evoked potential changes in predicting postoperative deficit in lumbar decompression and fusion surgery: a systematic review and meta-analysis.

PURPOSE: The primary aim of this study was to evaluate whether TcMEP alarms can predict the occurrence of postoperative neurological deficit in patients undergoing lumbar spine surgery. The secondary aim was to determine whether the various types of TcMEP alarms including transient and persistent changes portend varying degrees of injury risk. METHODS: This was a systematic review and meta-analysis of the literature from PubMed, Web of Science, and Embase regarding outcomes of transcranial motor-evoked potential (TcMEP) monitoring during lumbar decompression and fusion surgery. The sensitivity, specificity, and diagnostic odds ratio (DOR) of TcMEP alarms for predicting postoperative deficit were calculated and presented with forest plots and a summary receiver operating characteristic curve. RESULTS: Eight studies were included, consisting of 4923 patients. The incidence of postoperative neurological deficit was 0.73% (36/4923). The incidence of deficits in patients with significant TcMEP changes was 11.79% (27/229), while the incidence in those without changes was 0.19% (9/4694). All TcMEP alarms had a pooled sensitivity and specificity of 63 and 95% with a DOR of 34.92 (95% CI 7.95-153.42). Transient and persistent changes had sensitivities of 29% and 47%, specificities of 96% and 98%, and DORs of 8.04 and 66.06, respectively. CONCLUSION: TcMEP monitoring has high specificity but low sensitivity for predicting postoperative neurological deficit in lumbar decompression and fusion surgery. Patients who awoke with new postoperative deficits were 35 times more likely to have experienced TcMEP changes intraoperatively, with persistent changes indicating higher risk of deficit than transient changes. LEVEL OF EVIDENCE II: Diagnostic Systematic Review.

A systematic review of cognitive function after carotid endarterectomy in asymptomatic patients.

OBJECTIVE: Asymptomatic carotid stenosis has been associated with a progressive decline in neurocognitive function. However, the effect of carotid endarterectomy (CEA) on this process is poorly understood. We aimed to evaluate preoperative and postoperative cognitive function changes in asymptomatic patients after CEA. METHODS: A systematic review of the existing reports in PubMed/MEDLINE, Embase, and Cochran databases was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement recommendations. All original retrospective or prospective studies (including cohort, cross-sectional, case-control, pilot studies, etc) and clinical trials that compared pre and postoperative neurocognitive function in asymptomatic patients with carotid stenosis after CEA, which were published from January 2000 to April 2021 were identified and considered eligible for inclusion in the study. RESULTS: Thirteen studies (502 CEAs) comparing cognitive function changes before and after CEA were identified. In 7 studies with a total 272 patients, a mean age range of 67.3 ± 4.8 to 76.35 years old, and follow-up ranging between 1 and 12 months, overall cognitive function improved after CEA. However, in 6 studies with a total sample of 230, a mean age range of 68.6 ± 6.9 to 74.4 ± 6.1 years, and follow-up ranged from 24 hours to 3 years, showed no change or decline in overall cognitive function after procedures. CONCLUSIONS: The lack of standardization of specific cognitive tests and cognitive function assessment timing after CEA does not allow for definite conclusions to be made. However, improving brain perfusion with a combination of CEA and statin therapy may be a protective strategy against cognitive function decline.

Predicting Unplanned Health Care Utilization and Cost: Comparing Patient-reported Outcomes Measurement Information System and Claims.

OBJECTIVES: There is little literature describing if and how payers are utilizing patient-reported outcomes to predict future costs. This study assessed if Patient-reported Outcomes Measurement Information System (PROMIS) domain scores, collected in routine practice at neurology clinics, improved payer predictive models for unplanned care utilization and cost. STUDY DESIGN: Retrospective cohort analysis of private Health Plan-insured patients with visits at 18 Health Plan-affiliated neurology clinics. METHODS: PROMIS domains (Anxiety v1.0, Cognitive Function Abilities v2.0, Depression v1.0, Fatigue v1.0, Pain Interference v1.0, Physical Function v2.0, Sleep Disturbance v1.0, and Ability to Participate in Social Roles and Activities v2.0) are collected as part of routine care. Data from patients' first PROMIS measures between June 27, 2018 and April 16, 2019 were extracted and combined with claims data. Using (1) claims data alone and (2) PROMIS and claims data, we examined the association of covariates to utilization (using a logit model) and cost (using a generalized linear model). We evaluated model fit using area under the receiver operating characteristic curve (for unplanned care utilization), akaike information criterion (for unplanned care costs), and sensitivity and specificity in predicting top 15% of unplanned care costs. RESULTS: Area under the receiver operating curve values were slightly higher, and akaike information criterion values were similar, for PROMIS plus claims covariates compared with claims alone. The PROMIS plus claims model had slightly higher sensitivity and equivalent specificity compared with claims-only models. CONCLUSION: One-time PROMIS measure data combined with claims data slightly improved predictive model performance compared with claims alone, but likely not to an extent that indicates improved practical utility for payers.

Predictive Factors of Perioperative Stroke-Related Mortality Following Vascular Surgery: A Retrospective Analysis.

OBJECTIVE: Vascular surgical procedures have one of the highest risks of perioperative stroke and stroke-related mortality, yet the independent risk factors contributing to this increased mortality have not been described. Perioperative strokes are thought to result from a combination of embolism and hypoperfusion mechanisms. The purpose of this study is to describe the independent predictors of perioperative stroke-related mortality in the vascular surgical population using the Pennsylvania Health Care Cost Containment Council (PHC4) database which collects cause of death data. METHODS: This retrospective, case-control study evaluated 4,128 patients aged 18-99 who underwent a vascular, non-carotid surgical procedure and subsequently suffered perioperative mortality. Common surgical comorbidities and risk factors for perioperative stroke, including carotid stenosis and atrial fibrillation, were evaluated in multivariate regression analysis. RESULTS: Patients with carotid stenosis were 2.6 (aOR, 95% CI 1.4-4.5) times more likely to suffer perioperative mortality from stroke than from other causes. Additionally, in-hospital stroke, history of stroke, admission from a healthcare facility, and cancer were all positive predictive factors, whereas atrial fibrillation, emergency admission, hypertension, and diabetes were associated with decreased risk of perioperative stroke-related mortality. CONCLUSIONS: Identification of vascular surgical population-specific predictors of stroke-related mortality can help to enhance preoperative risk-stratification tools and guide perioperative management of identified high-risk patients. Increased neurophysiologic monitoring in the perioperative period to prevent delays in diagnosis of perioperative stroke offers a strategy to reduce risk of perioperative stroke-related mortality in vascular surgical patients.

Diagnostic accuracy of somatosensory evoked potentials during intracranial aneurysm clipping for perioperative stroke.

Somatosensory evoked potentials (SSEPs) are utilized during aneurysm clipping to detect intraoperative ischemia. We assess the diagnostic accuracy of SSEPs in predicting perioperative stroke during aneurysm clipping. A retrospective review was conducted of 429 consecutive patients who underwent surgical clipping for ruptured and unruptured cerebral aneurysms with intraoperative SSEP monitoring from 2006 to 2013. The relationship between perioperative stroke and SSEP changes was analyzed by calculating the sensitivity, specificity, and area under a Receiving Operating Characteristic curve. Sensitivity and specificity were 42% and 90%, respectively. Area under the curve was 0.66 (95% confidence interval, 0.53-0.79). Reclassification of reversible temporary clip changes to correct for paradoxical classification of SSEP false positives raised the sensitivity from 42 to 65% (p = 0.041, Chi squared test). EEG (electroencephalography) changes increased the specificity (98% vs. 90%, p < 0.001, McNemar's test), but not sensitivity (48% vs. 42%, p = 0.621, McNemar's test) of SSEPs for perioperative stroke. A stepwise logistic regression model selected SSEP amplitude loss (p = 0.006, OR = 3.7 [95% CI 1.5-9.2]) and the SSEP change duration (p = 0.034, OR = 1.8 [95% CI 1.1-3.1]) as independent predictors of perioperative stroke. SSEP changes induced by temporary clipping were highly reversible compared to other SSEP changes (94% vs. 60%, p = 0.003, Fisher exact test), and typically responded to clip removal or readjustment. SSEP changes have high specificity and modest sensitivity for perioperative stroke. Stroke risk is a function of both the magnitude of SSEP amplitude loss and the duration of its loss. Given the modest sensitivity, patients may benefit from multimodal monitoring including motor-evoked potentials during cerebral aneurysm surgery.

Perioperative Stroke and Readmissions Rates in Noncardiac Non-Neurologic Surgery.

BACKGROUND AND AIM: Perioperative stroke is a feared and potentially disastrous complication of surgery. Postdischarge care, specifically hospital readmissions, can significantly impact postsurgical recovery and provides a useful metric for quality care. Our primary aim was examining 30-day readmissions for patients who had a perioperative stroke undergoing noncardiac non-neurosurgery. METHODS: We analyzed data from the State Inpatient Database, a database of community hospital discharges, in California between 2008 and2011. Surgical patients undergoing one of the 10 highest-volume procedures were included; patients less than 18 years old, undergoing pregnancy-related procedures, or who died in-hospital were excluded. Our dataset covariates included demographic and clinical variables, comorbidities, and discharge location. After running an initial bivariate analysis using Chi-square and t-tests and testing for multicollinearity, logistical models were run to calculate adjusted odds ratios and confidence intervals for readmission predictors. RESULTS: 30-day readmissions for patients with perioperative stroke (n = 1613) occurred at a rate of 21.08% (340 patients), compared to 6.29% (63,856 patients) for patients without perioperative stroke (adjusted OR = 1.40, 95% CI 1.23-1.59, P < .0001). Demographic predictors of 30-day readmissions included male sex and African-American race. Clinical predictors of 30-day readmissions included several comorbidities (i.e. liver disease, hypertension), and discharge to a postacute care facility. Key 30-day readmission diagnoses for perioperative stroke patients included septicemia, stroke, aspiration pneumonitis, and urinary tract infections. CONCLUSIONS: Patients with perioperative stroke have high 30-day readmissions rates. A number of demographic and clinical factors increase readmission risk in this population. Further research is warranted to better support patients with perioperative stroke undergoing care transitions.

Independent Predictors of Perioperative Stroke-Related Mortality after Cardiac Surgery.

BACKGROUND AND PURPOSE: Perioperative stroke remains a devastating complication after cardiac surgery and is associated with significant morbidity and mortality. Despite the significant contribution of stroke to perioperative mortality, risk factors for perioperative stroke-related mortality have not been well characterized. Our aim was to identify independent predictors of perioperative stroke-related mortality after cardiac surgery, using the Pennsylvania Health Care Cost Containment Council (PHC4) database which provides information on cause of death. METHODS: We retrospectively examined patient medical records from 2012 to 2014 of 3345 patients (ages 18-99) who underwent a cardiac surgical procedure and suffered perioperative (30-day) mortality. Perioperative stroke-related mortality was identified by International Classification of Diseases, Tenth Revision, Clinical Modification cause of death codes. We performed Fisher's exact test and multivariate analysis to identify comorbidities that independently predict perioperative stroke-related mortality. RESULTS: After controlling for all variables with multivariate analysis, we found that patients with carotid stenosis were 4.9 (adjusted odds ratio [aOR], 95% confidence interval [CI] 1.8-12.8) times more likely to die from a stroke than from other causes, when compared to patients without carotid stenosis. Other independent predictors of perioperative stroke-related mortality included in-hospital stroke (aOR 108.8, 95%CI 48.2-245.9), history of stroke (aOR 17.1, 95%CI 3.3-88.4), and age ≥ 80 (aOR 4.9, 95%CI 2.1-11.2). CONCLUSIONS: This is the first study to establish carotid stenosis, among other comorbidities, as an independent predictor of perioperative stroke-related mortality after cardiac surgery. Understanding risk factors for mortality from stroke will help enhance the efficacy of preoperative screening, intraoperative neurophysiological monitoring, and potential treatments for stroke. Interventions to manage carotid stenosis and other identified risk factors prior to, during, or immediately after surgery may have the potential to reduce perioperative stroke-related mortality after cardiac surgery.

Last Electrically Well: Intraoperative Neurophysiological Monitoring for Identification and Triage of Large Vessel Occlusions.

INTRODUCTION: Intra-operative stroke (IOS) is associated with poor clinical outcome as detection is often delayed and time of symptom onset or patient's last known well (LKW) is uncertain. Intra-operative neurophysiological monitoring (IONM) is uniquely capable of detecting onset of neurological dysfunction in anesthetized patients, thereby precisely defining time last electrically well (LEW). This novel parameter may aid in the detection of large vessel occlusion (LVO) and prompt treatment with endovascular thrombectomy (EVT). METHODS: We performed a retrospective analysis of a prospectively maintained AIS and LVO database from May 2018-August 2019. Inclusion criteria required any surgical procedure under general anesthesia (GA) utilizing EEG (electroencephalography) and/or SSEP (somatosensory evoked potentials) monitoring with development of intraoperative focal persistent changes using predefined alarm criteria and who were considered for EVT. RESULT: Five cases were identified. LKW to closure time ranged from 66 to 321 minutes, while LEW to closure time ranged from 43 to 174 min. All LVOs were in the anterior circulation. Angiography was not pursued in two cases due to large established infarct (both patients expired in the hospital). EVT was pursued in two cases with successful recanalization and spontaneous recanalization was noted in one patient (mRS 0-3 at 90 days was achieved in all 3 cases). CONCLUSIONS: This study demonstrates that significant IONM changes can accurately identify patients with an acute LVO in the operative setting. Given the challenges of recognizing peri-operative stroke, LEW may be an appropriate surrogate to quickly identify and treat IOS.

Risk factors for positioning-related somatosensory evoked potential changes in 3946 spinal surgeries.

The goal of this study was to evaluate the risk factors associated with positioning-related SSEP changes (PRSC). The study investigated the association between 18 plausible risk factors and the occurrence of intraoperative PRSC. Risk factors investigated included demographic variables, comorbidities, and procedure related variables. All patients were treated by the University of Pittsburgh Medical Center from 2010 to 2012. We used univariate and multivariate statistical methods. 69 out of the 3946 (1.75%) spinal surgeries resulted in PRSC changes. The risk of PRSC was increased for women (p < 0.001), patients older than 65 years of age (p = 0.01), higher BMI (p < 0.001) patients, smokers (p < 0.001), and patients with hypertension (p < 0.001). No associations were found between PRSC and age greater than 80 years, diabetes mellitus, cardiovascular disease, and peripheral vascular disease. Three surgical situations were associated with PRSC including abnormal baselines (p < 0.001), patients in the "superman" position (p < 0.001), and patients in surgical procedures that extended over 200 min (p = 0.03). Patients with higher BMIs and who are undergoing spinal surgery longer than 200 min, with abnormal baselines, must be positioned with meticulous attention. Gender, hypertension, and smoking were also found to be risk factors from their odds ratios.

Carotid Artery Disease as a Predictor of In-Hospital Postoperative Stroke After Coronary Artery Bypass Grafting From 1999 to 2011.

BACKGROUND: In this study, the risk factors for stroke after coronary artery bypass grafting (CABG) were examined. In particular, the role of asymptomatic carotid artery stenosis (both unilateral and bilateral) as a predictor of in-hospital postoperative stroke was investigated. Finally, the trends surrounding in-hospital postoperative stroke from 1999 to 2011 also were examined. The purpose of the study was to appropriately identify patients at high risk for stroke after CABG and spark discussion about the perioperative management of such patients. MATERIALS AND METHODS: Data from the Nationwide Inpatient Sample from 1999 to 2011 were analyzed retrospectively. The study cohort was identified using the International Classification of Diseases, Ninth Revision, Clinical Modification and Projection Clinical Classification Software codes. Exploratory statistics, univariate analyses, and multivariable regression were used for this study. RESULTS: The analysis demonstrated that both asymptomatic unilateral and bilateral carotid stenoses were independent risk factors for in-hospital postoperative stroke. In addition, increasing age, female sex, increasing van Walraven score, paralysis, neurologic disorders, history of infective endocarditis, asymptomatic basilar stenosis, and cerebral occlusion all were demonstrated to be statistically significant predictors of stroke. Patients with carotid stenosis and a van Walraven score >14 were found to be particularly vulnerable to in-hospital postoperative stroke. Lastly, predictors of carotid stenosis were examined, and increasing age, female sex, and increasing van Walraven score all were found to be significant predictors of asymptomatic carotid stenosis. CONCLUSIONS: This study examined risk factors for stroke after CABG in a large, longitudinal, and population-based database. The study found that both unilateral and bilateral asymptomatic carotid stenoses are indeed risk factors for in-hospital postoperative stroke. In addition, a number of other predictors were identified. These results can be used to identify patients at high risk for perioperative stroke and hopefully decrease the rate of a devastating complication of CABG.

The Prevalence and Impact of Status Epilepticus Secondary to Intracerebral Hemorrhage: Results from the US Nationwide Inpatient Sample.

BACKGROUND: Status epilepticus (SE) has been identified as a predictor of morbidity and mortality in many acute brain injury patient populations. We aimed to assess the prevalence and impact of SE after intracerebral hemorrhage (ICH) in a large patient sample to overcome limitations in previous small patient sample studies. METHODS: We queried the Nationwide Inpatient Sample for patients admitted for ICH from 1999 to 2011, excluding patients with other acute brain injuries. Patients were stratified into SE diagnosis and no SE diagnosis cohorts. We identified independent risk factors for SE and assessed the impact of SE on morbidity and mortality with multivariable logistic regression models. Logistic regression was used to evaluate the trend in SE diagnoses over time as well. RESULTS: SE was associated with significantly increased odds of both mortality and morbidity (odds ratios (OR) 1.18 [confidence intervals (CI) 1.01-1.39], and OR 1.53 [CI 1.22-1.91], respectively). Risk factors for SE included female sex (OR 1.17 [CI 1.01-1.35]), categorical van Walraven score (vWr 5-14: OR 1.68 [CI 1.41-2.01]; vWr > 14: OR 3.77 [CI 2.98-4.76]), sepsis (OR 2.06 [CI 1.58-2.68]), and encephalopathy (OR 3.14 [CI 2.49-3.96]). Age was found to be associated with reduced odds of SE (OR 0.97 [CI 0.97-0.97]). From 1999 to 2011, prevalence of SE diagnosis increased from 0.25 to 0.61% (p < 0.001). Factors associated with SE were female sex, medium and high risk vWr score, sepsis, and encephalopathy. Independent predictors associated with increased mortality from SE were increased age, pneumonia, myocardial infarction, cardiac arrest, and sepsis. CONCLUSIONS: SE is a significant, likely underdiagnosed, predictor of morbidity and mortality after ICH. Future studies are necessary to better identify which patients are at highest risk of SE to guide resource utilization.

Perioperative strokes following combined coronary artery bypass grafting and carotid endarterectomy: A nationwide perspective.

BACKGROUND: To assess the risk of perioperative stroke on in-hospital morbidity and mortality following combined coronary artery bypass grafting (CABG) and carotid endarterectomy (CEA). MATERIALS AND METHODS: Data from the National Inpatient Sample (NIS) database for all patients who underwent CABG with CEA were identified using ICD-9 codes. Combined procedures were identified as CEA and CABG procedures that happened on the same day. Various preoperative and perioperative risk factors and their association with in-hospital mortality and morbidity were studied. RESULTS: A total of 8457 patients underwent combined CABG and CEA from 1999 to 2011. The average age of the patient population was 69.98 years. A total of 6.17% (n = 521) of the patients developed perioperative strokes following combined CABG and CEA. An in-hospital mortality of 4.96% and morbidity of 66.35% was observed in the patient cohort. Patients with perioperative strokes showed a mortality of 19% and a morbidity of 89.34%. Other notable risk factors for in-hospital mortality and morbidity were heart failure, paralysis, renal failure, coagulopathy, weight loss and fluid and electrolyte disturbances, and postoperative myocardial infarction. CONCLUSION: A strong association was found to exist between perioperative stroke and in-hospital mortality and morbidity after combined CABG and CEA. CEA procedures are thought to mitigate the high stroke rate of 3-5% post-CABG, but our study found that combined procedures exhibit a similar stroke risk undercutting their effectiveness. Further investigative studies on combined CABG+CEA are needed to assess risk-stratification for better patient selection and examine other preventative strategies to minimize the risk of ischemic strokes.

Perioperative Strokes Following Surgical Correction of Mitral Valves: A Systematic Review and Meta-Analysis.

OBJECTIVE: The primary aim of this meta-analysis was to quantify the impact of perioperative strokes on stroke-related mortality after open mitral valve (MV) procedures were performed. METHODS: An electronic search of the PubMed, Embase, and the Web of Science databases was performed to retrieve articles published up to December 2015, relevant to patients undergoing MV procedures. Data were extracted from the final list of 25 studies to calculate a summary OR for 30-day stroke-related mortality. RESULTS: The stroke rate in the total sample population was 1.62% (73/4,498). The 30-day all-cause mortality rate was 3.51% (158/4,498). The percentage of total deaths caused by stroke was 6.87%. The summary OR of stroke-related mortality following MV procedures was estimated to be 7.22 (95% CI 4.13-12.63, p < 0.0001). A subgroup analysis was done for studies involving concomitant MV surgery and coronary artery bypass grafting. The summary estimate of the subgroup showed an OR of 8.508 (95% CI 1.552-46.622, p = 0.0136). CONCLUSION: Perioperative strokes following open MV procedures may be associated with more than 7 times greater odds of 30-day stroke-related mortality. They appear to be more commonly occurring than what is reported by current literature, making further studies investigating possible mechanisms and preventive measures a priority.

Perioperative Strokes and Early Outcomes in Mitral Valve Surgery: A Nationwide Analysis.

OBJECTIVE: To demonstrate the role of perioperative stroke as an independent risk factor for in-hospital morbidity and mortality after mitral valve surgery and review the trends in the early outcomes of mitral valve surgery over the past decade. DESIGN: Using data from the National Inpatient Sample database for analysis, all patients who underwent isolated mitral valve procedures were identified using International Classification of Diseases-Ninth Revision codes. Univariate and multivariate analyses of risk factors of in-hospital mortality and morbidity were performed. SETTING: Multi-institutional. PARTICIPANTS: The study comprised patients who underwent mitral valve procedures from 1999 to 2011. INTERVENTIONS: Mitral valve repair or replacement. MEASUREMENTS AND MAIN RESULTS: Data on 21,821 patients showed an in-hospital mortality of 5.5% and morbidity of 63.30% (p<0.05). Perioperative strokes were experienced by 3.89% of the cohort after isolated mitral valve surgery (p<0.05). Independent predictors of adverse outcomes were age, female sex, emergency surgery, arrhythmias, hypertension, renal failure, coagulopathy, neurologic disorders, weight loss, anemia, postoperative cardiac arrest, and myocardial infarction. Perioperative strokes were found to be the strongest risk factor for postoperative mortality (odds ratio 2.34, 95% confidence interval 1.83-2.98) and morbidity (odds ratio 4.53, 95% confidence interval 3.34-6.15). CONCLUSION: Age, female sex, emergency surgery, arrhythmias, hypertension, renal failure, coagulopathy, neurologic disorders, weight loss, fluid and electrolyte imbalance, anemia, postoperative cardiac arrest, and myocardial infarction were found to be significant predictors of morbidity and mortality after mitral valve surgery, with perioperative strokes posing the strongest risk. The trends in the last 10 years indicated a decrease in mortality and an increase in morbidity. Preoperative risk stratification and intraoperative identification for impending strokes appear warranted.

Delirium Following Transcatheter Aortic Valve Replacement: National Inpatient Sample Analysis.

OBJECTIVE: To investigate the risk factors for postoperative delirium and the impact of delirium on mortality and morbidity following transcatheter aortic valve implantation (TAVI). DESIGN: Patients who underwent TAVI were identified using the International Classification of Diseases, 9th revision clinical modification codes from the National Inpatient Sample database. Statistical analysis of preoperative and perioperative risk factors was done to identify the independent risk factors for delirium after TAVI. SETTING: Multi-institutional. PARTICIPANTS: Patients who underwent TAVI from 2012 to 2013. INTERVENTIONS: TAVI. MEASUREMENTS AND MAIN RESULTS: Over the period of 2 years (2012-2013), 7,566 patients underwent TAVI. The incidence of delirium post-TAVI was 4.57% (345). Age >85 (odds ratio [OR] 1.03; 95% confidence interval [CI] 1.01-1.05; p = 0.003), electrolyte abnormalities (OR 1.83; 95% CI 1.17-2.87; p = 0.008), prior neurologic illness (OR 1.67; 95% CI 1.10-3.15; p = 0.01), and weight loss in the hospital (OR 1.77; 95% CI 1.05-2.99; p = 0.03) were independent risk factors for postoperative delirium (POD). Unilateral or bilateral carotid stenosis did not predispose to the development of delirium. POD was an independent risk factor for procedural morbidity (OR 3.29; 95% CI 2.05-5.28; p < 0.001). POD did not increase the risk of in-house mortality after TAVI. CONCLUSION: Age of >85, electrolyte disturbance, pre-existing neurologic disease and weight loss were found to be independent risk factors for delirium. POD was associated significantly with morbidity. Owing to a significant increase in the morbidity, a thorough screening protocol and effective strategies to predict, prevent, and treat postoperative delirium would reduce the cost associated with TAVI.

Transcranial Doppler Monitoring in Carotid Endarterectomy: A Systematic Review and Meta-analysis.

OBJECTIVES: To evaluate the efficacy of intraoperative transcranial Doppler monitoring in predicting perioperative strokes after carotid endarterectomy (CEA). METHODS: An electronic search of PubMed, Embase, and Web of Science databases was conducted for studies on transcranial Doppler monitoring in CEA published from January 1970 through September 2015. All titles and abstracts were independently screened on the basis of predetermined inclusion criteria, which included randomized clinical trials and prospective or retrospective cohort reviews, patients who underwent CEA with intraoperative transcranial Doppler monitoring (either middle cerebral artery velocity [MCAV] or cerebral microembolic signals [MES]) and postoperative neurologic assessments up to 30 days after the surgery, and studies including an abstract, published in English on adult humans 18 years and older with a sample size of 50 or greater. RESULTS: A total of 25articles with a sample population of 4705 patients were analyzed. Among the study patients, 189 developed perioperative strokes. Transcranial Doppler monitoring (either MCAV or MES) showed specificity of 72.7% (95% confidence interval [CI], 61.2%-81.8%) and sensitivity of 56.1% (95% CI, 46.8%-65.0%) for predicting perioperative strokes. Intraoperative MCAV changes during CEA showed strong specificity of 84.1% (95% CI, 74.4%-90.6) and sensitivity of 49.7% (95% CI, 40.6%-58.8) for predicting perioperative strokes. CONCLUSIONS: Patients with perioperative strokes are 4 times more likely to have had transcranial Doppler changes (either MCAV or MES) during CEA compared to patients without strokes. Simultaneous MCAV and MES monitoring by transcranial Doppler sonography and combined intraoperative monitoring of transcranial Doppler sonography with somatosensory evoked potentials and electroencephalography during CEA to predict perioperative stroke could not be evaluated because of a lack of clinical studies combining these measures.

Alarm criteria for motor evoked potentials.

OBJECTIVE: To evaluate three commonly used alarm criteria for interpreting the significance and diagnostic value of transcranial motor evoked potential (TcMEP) changes during spinal surgery. MATERIALS AND METHODS: A systematic literature search was performed using PubMed/MEDLINE, Web of Science, and EMBASE from 1945 to January 2014. We included all those studies that were (1) randomized controlled trials, prospective studies, or retrospective cohort studies, (2) conducted among patients undergoing surgery on the spine or spinal cord with TcMEP monitoring, (3) conducted in a group of ≥50 patients, (4) that were inclusive of immediate postoperative neurological assessment (within 24 h), and (5) which were published in English. RESULTS: Twenty-five studies involving 9409 patients were included. The incidence of neurological deficits was 1.82%. The overall sensitivity and specificity of all reported TcMEP changes was 82.1% (95% confidence interval [CI]: 73-88.6%) and 95.7% (95% CI: 93.7-97.1%), respectively. The sensitivity and specificity of each alarm criteria were evaluated: 50% reduction in amplitude, sensitivity 63.2% (95% CI: 47-76.8%), and specificity 96.7% (95% CI: 96.4-99.2%); 80% reduction in amplitude, sensitivity 71.7% (95% CI; 42-89.9%), and specificity 98.3% (95% CI: 96.4-99.2%); total signal loss, sensitivity 30% (95% CI: 17.6-46.4%), and specificity 99.3% (95% CI: 98.6-99.7%). CONCLUSIONS: No statistically significant differences between using reductions in amplitude of 50% and 80% as alarm criteria were found in terms of sensitivity and specificity. Total loss was found to have a statistically significant increase in specificity. TcMEP monitoring is a highly specific and sensitive diagnostic tool for the detection of neurological defects during spinal surgery.