Evaluation of simulation models in neurosurgical training according to face, content, and construct validity: a systematic review.

BACKGROUND: Neurosurgical training has been traditionally based on an apprenticeship model. However, restrictions on clinical exposure reduce trainees' operative experience. Simulation models may allow for a more efficient, feasible, and time-effective acquisition of skills. Our objectives were to use face, content, and construct validity to review the use of simulation models in neurosurgical education. METHODS: PubMed, Web of Science, and Scopus were queried for eligible studies. After excluding duplicates, 1204 studies were screened. Eighteen studies were included in the final review. RESULTS: Neurosurgical skills assessed included aneurysm clipping (n = 6), craniotomy and burr hole drilling (n = 2), tumour resection (n = 4), and vessel suturing (n = 3). All studies assessed face validity, 11 assessed content, and 6 assessed construct validity. Animal models (n = 5), synthetic models (n = 7), and VR models (n = 6) were assessed. In face validation, all studies rated visual realism favourably, but haptic realism was key limitation. The synthetic models ranked a high median tactile realism (4 out of 5) compared to other models. Assessment of content validity showed positive findings for anatomical and procedural education, but the models provided more benefit to the novice than the experienced group. The cadaver models were perceived to be the most anatomically realistic by study participants. Construct validity showed a statistically significant proficiency increase among the junior group compared to the senior group across all modalities. CONCLUSION: Our review highlights evidence on the feasibility of implementing simulation models in neurosurgical training. Studies should include predictive validity to assess future skill on an individual on whom the same procedure will be administered. This study shows that future neurosurgical training systems call for surgical simulation and objectively validated models.

International practice variation in perioperative laboratory testing in glioblastoma patients-a retrospective cohort study.

PURPOSE: Although standard-of-care has been defined for the treatment of glioblastoma patients, substantial practice variation exists in the day-to-day clinical management. This study aims to compare the use of laboratory tests in the perioperative care of glioblastoma patients between two tertiary academic centers-Brigham and Women's Hospital (BWH), Boston, USA, and University Medical Center Utrecht (UMCU), Utrecht, the Netherlands. METHODS: All glioblastoma patients treated according to standard-of-care between 2005 and 2013 were included. We compared the number of blood drawings and laboratory tests performed during the 70-day perioperative period using a Poisson regression model, as well as the estimated laboratory costs per patient. Additionally, we compared the likelihood of an abnormal test result using a generalized linear mixed effects model. RESULTS: After correction for age, sex, IDH1 status, postoperative KPS score, length of stay, and survival status, the number of blood drawings and laboratory tests during the perioperative period were 3.7-fold (p < 0.001) and 4.7-fold (p < 0.001) higher, respectively, in BWH compared to UMCU patients. The estimated median laboratory costs per patient were 82 euros in UMCU and 256 euros in BWH. Furthermore, the likelihood of an abnormal test result was lower in BWH (odds ratio [OR] 0.75, p < 0.001), except when the prior test result was abnormal as well (OR 2.09, p < 0.001). CONCLUSIONS: Our results suggest a substantially lower clinical threshold for ordering laboratory tests in BWH compared to UMCU. Further investigating the clinical consequences of laboratory testing could identify over and underuse, decrease healthcare costs, and reduce unnecessary discomfort that patients are exposed to.

Incidence and Outcomes of Registry-Based Acute Myocardial Infarction After Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Acute myocardial infarction (AMI) is the rarest and least studied cardiac complication of aneurysmal subarachnoid hemorrhage (aSAH). Precise estimates of the incidence of AMI after aSAH are unavailable. Our goal was to estimate the incidence of registry-based AMI (rb-AMI) after aSAH and determine its association with clinical outcomes. METHODS: Adult patients with aSAH in the National Inpatient Samples from 2002 to 2014 were included in the study. We evaluated risk factors for rb-AMI using univariate and multivariate regression models. Clinical outcomes that were assessed included functional status at discharge, in-patient mortality, length of stay, and total hospitalization cost, adjusting for patient demographics and cardiovascular risk factors through an inverse probability weighted analysis. Subgroup analyses were further performed stratified by rb-AMI type (ST-segment elevation myocardial infarction [STEMI] vs. non-STEMI [NSTEMI]). RESULTS: A total of 139,734 patients with aSAH were identified, 3.6% of whom had rb-AMI. NSTEMI was the most common type of rb-AMI occurring after aSAH (71% vs. 29% for NSTEMI vs. STEMI, respectively). Patient characteristics associated with higher odds of rb-AMI included age, female sex, poor aSAH grade, and various cardiovascular risk factors. Rb-AMI was also associated with poor functional status at discharge, higher in-hospital mortality, and a longer and more costly hospital stay. CONCLUSIONS: Rb-AMI occurs in 3.6% of patients with aSAH and is associated with poor functional status at discharge, higher in-patient mortality, and a longer and more costly hospitalization. Differentiating between different types of rb-AMI would be important in optimizing the management of patients with aSAH. Our definition of rb-AMI likely includes patients with neurogenic stress cardiomyopathy, which may confound the results.

Survival prediction of glioblastoma patients-are we there yet? A systematic review of prognostic modeling for glioblastoma and its clinical potential.

Glioblastoma is associated with a poor prognosis. Even though survival statistics are well-described at the population level, it remains challenging to predict the prognosis of an individual patient despite the increasing number of prognostic models. The aim of this study is to systematically review the literature on prognostic modeling in glioblastoma patients. A systematic literature search was performed to identify all relevant studies that developed a prognostic model for predicting overall survival in glioblastoma patients following the PRISMA guidelines. Participants, type of input, algorithm type, validation, and testing procedures were reviewed per prognostic model. Among 595 citations, 27 studies were included for qualitative review. The included studies developed and evaluated a total of 59 models, of which only seven were externally validated in a different patient cohort. The predictive performance among these studies varied widely according to the AUC (0.58-0.98), accuracy (0.69-0.98), and C-index (0.66-0.70). Three studies deployed their model as an online prediction tool, all of which were based on a statistical algorithm. The increasing performance of survival prediction models will aid personalized clinical decision-making in glioblastoma patients. The scientific realm is gravitating towards the use of machine learning models developed on high-dimensional data, often with promising results. However, none of these models has been implemented into clinical care. To facilitate the clinical implementation of high-performing survival prediction models, future efforts should focus on harmonizing data acquisition methods, improving model interpretability, and externally validating these models in multicentered, prospective fashion.

Fibrinolytics and Intraventricular Hemorrhage: A Systematic Review and Meta-analysis.

Intraventricular hemorrhage (IVH) is an independent poor prognostic factor in subarachnoid and intra-parenchymal hemorrhage. The use of intraventricular fibrinolytics (IVF) has long been debated, and its exact effects on outcomes are unknown. A systematic review and meta-analysis were performed in accordance with the PRISMA guidelines to assess the impact of IVF after non-traumatic IVH on mortality, functional outcome, intracranial bleeding, ventriculitis, time until clearance of third and fourth ventricles, obstruction of external ventricular drains (EVD), and shunt dependency. Nineteen studies were included in the meta-analysis, totaling 1020 patients. IVF was associated with lower mortality (relative risk [RR] 0.58; 95% confidence interval [CI] 0.47-0.72), fewer EVD obstructions (RR 0.41; 95% CI 0.22-0.74), and a shorter time until clearance of the ventricles (median difference [MD] - 4.05 days; 95% CI - 5.52 to - 2.57). There was no difference in good functional outcome, RR 1.41 (95% CI 0.98-2.03), or shunt dependency, RR 0.93 (95% CI 0.70-1.22). Correction for publication bias predicted an increased risk of intracranial bleeding, RR 1.67 (95% CI 1.01-2.74) and a lower risk of ventriculitis, RR 0.68 (95% CI 0.45-1.03) in IVH patients treated with IVF. IVF was associated with improved survival, faster clearance of blood from the ventricles and fewer drain obstructions, but further research is warranted to elucidate the effects on ventriculitis, long-term functional outcomes, and re-hemorrhage.

Hyperosmolar Therapy in Pediatric Severe Traumatic Brain Injury-A Systematic Review.

OBJECTIVES: Traumatic brain injury is a leading cause of hospital visits for children. Hyperosmolar therapy is often used to treat severe traumatic brain injury. Hypertonic saline is used predominantly, yet there remains disagreement about whether hypertonic saline or mannitol is more effective. DATA SOURCES: Literature search was conducted using Pubmed, Cochrane, and Embase. Systematic review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. STUDY SELECTION: Retrospective and prospective studies assessing use of hyperosmolar therapy in pediatric patients with severe traumatic brain injury were included. DATA EXTRACTION: Two independent authors performed article review. Two-thousand two-hundred thirty unique articles were initially evaluated, 11 were included in the final analysis, with a total of 358 patients. Study quality was assessed using Modified Newcastle-Ottawa Scale and Jadad score. DATA SYNTHESIS: Of the 11 studies, all evaluated hypertonic saline and four evaluated both hypertonic saline and mannitol. Nine reported that hypertonic saline lowered intracranial pressure and two reported that mannitol lowered intracranial pressure. The studies varied significantly in dose, concentration, and administrations schedule for both hypertonic saline and mannitol. Five studies were prospective, but only one directly compared mannitol to hypertonic saline. The prospective comparison study found no difference in physiologic outcomes. Clinical outcomes were reported using different measures across studies. For hypertonic saline-treated patients, mechanical ventilation was required for 6.9-9 days, decompressive craniectomy was required for 6.25-29.3% of patients, ICU length of stay was 8.0-10.6 days, in-hospital mortality was 10-48%, and 6-month mortality was 7-17%. In mannitol-treated patients, ICU length of stay was 9.5 days, in-hospital mortality was 56%, and 6-month mortality was 19%. CONCLUSIONS: Both hypertonic saline and mannitol appear to lower intracranial pressure and improve clinical outcomes in pediatric severe traumatic brain injury, but the evidence is extremely fractured both in the method of treatment and in the evaluation of outcomes. Given the paucity of high-quality data, it is difficult to definitively conclude which agent is better or what treatment protocol to follow.

Predicting discharge placement after elective surgery for lumbar spinal stenosis using machine learning methods.

PURPOSE: An excessive amount of total hospitalization is caused by delays due to patients waiting to be placed in a rehabilitation facility or skilled nursing facility (RF/SNF). An accurate preoperative prediction of who would need a RF/SNF place after surgery could reduce costs and allow more efficient organizational planning. We aimed to develop a machine learning algorithm that predicts non-home discharge after elective surgery for lumbar spinal stenosis. METHODS: We used the American College of Surgeons National Surgical Quality Improvement Program to select patient that underwent elective surgery for lumbar spinal stenosis between 2009 and 2016. The primary outcome measure for the algorithm was non-home discharge. Four machine learning algorithms were developed to predict non-home discharge. Performance of the algorithms was measured with discrimination, calibration, and an overall performance score. RESULTS: We included 28,600 patients with a median age of 67 (interquartile range 58-74). The non-home discharge rate was 18.2%. Our final model consisted of the following variables: age, sex, body mass index, diabetes, functional status, ASA class, level, fusion, preoperative hematocrit, and preoperative serum creatinine. The neural network was the best model based on discrimination (c-statistic = 0.751), calibration (slope = 0.933; intercept = 0.037), and overall performance (Brier score = 0.131). CONCLUSIONS: A machine learning algorithm is able to predict discharge placement after surgery for lumbar spinal stenosis with both good discrimination and calibration. Implementing this type of algorithm in clinical practice could avert risks associated with delayed discharge and lower costs. These slides can be retrieved under Electronic Supplementary Material.

Non-electrographic Seizures Due to Subdural Hematoma: A Case Series and Review of the Literature.

Seizures due to subdural hematoma (SDH) are a common finding, typically diagnosed using electroencephalography (EEG). At times, aggressive management of seizures is necessary to improve neurologic recovery and outcomes. Here, we present three patients who had undergone emergent SDH evacuation and showed postoperative focal deficits without accompanying electrographic epileptiform activity. After infarction and recurrent hemorrhage were ruled out, seizures were suspected despite a negative EEG. Patients were treated aggressively with AEDs and eventually showed clinical improvement. Long-term monitoring with EEG revealed electrographic seizures in a delayed fashion. EEG recordings are an important tool for seizure detection, but should be used as an adjunct to, rather than a replacement for, the clinical examination in the acute setting. At times, aggressive treatment of suspected postoperative seizures is warranted despite lack of corresponding electrographic activity and can improve clinical outcomes.

Venous thromboembolism and intracranial hemorrhage after craniotomy for primary malignant brain tumors: a National Surgical Quality Improvement Program analysis.

Venous thromboembolism (VTE), including deep venous thrombosis (DVT) and pulmonary embolism (PE), frequently complicates the postoperative course of primary malignant brain tumor patients. Thromboprophylactic anticoagulation is commonly used to prevent VTE at the risk of intracranial hemorrhage (ICH). We extracted all patients who underwent craniotomy for a primary malignant brain tumor from the National Surgical Quality Improvement Program (NSQIP) registry (2005-2015) to perform a time-to-event analysis and identify relevant predictors of DVT, PE, and ICH within 30 days after surgery. Among the 7376 identified patients, the complication rates were 2.6, 1.5, and 1.3% for DVT, PE, and ICH, respectively. VTE was the second-most common major complication and third-most common reason for readmission. ICH was the most common reason for reoperation. The increased risk of VTE extends beyond the period of hospitalization, especially for PE, whereas ICH occurred predominantly within the first days after surgery. Older age and higher BMI were overall predictors of VTE. Dependent functional status and longer operative times were predictive for VTE during hospitalization, but not for post-discharge events. Admission two or more days before surgery was predictive for DVT, but not for PE. Preoperative steroid usage and male gender were predictive for post-discharge DVT and PE, respectively. ICH was associated with various comorbidities and longer operative times. This multicenter study demonstrates distinct critical time periods for the development of thrombotic and hemorrhagic events after craniotomy. Furthermore, the VTE risk profile depends on the type of VTE (DVT vs. PE) and clinical setting (hospitalized vs. post-discharge patients).

Development of machine learning algorithms for prediction of discharge disposition after elective inpatient surgery for lumbar degenerative disc disorders.

OBJECTIVEIf not anticipated and prearranged, hospital stay can be prolonged while the patient awaits placement in a rehabilitation unit or skilled nursing facility following elective spine surgery. Preoperative prediction of the likelihood of postoperative discharge to any setting other than home (i.e., nonroutine discharge) after elective inpatient spine surgery would be helpful in terms of decreasing hospital length of stay. The purpose of this study was to use machine learning algorithms to develop an open-access web application for preoperative prediction of nonroutine discharges in surgery for elective inpatient lumbar degenerative disc disorders.METHODSThe American College of Surgeons National Surgical Quality Improvement Program was queried to identify patients who underwent elective inpatient spine surgery for lumbar disc herniation or lumbar disc degeneration between 2011 and 2016. Four machine learning algorithms were developed to predict nonroutine discharge and the best algorithm was incorporated into an open-access web application.RESULTSThe rate of nonroutine discharge for 26,364 patients who underwent elective inpatient surgery for lumbar degenerative disc disorders was 9.28%. Predictive factors selected by random forest algorithms were age, sex, body mass index, fusion, level, functional status, extent and severity of comorbid disease (American Society of Anesthesiologists classification), diabetes, and preoperative hematocrit level. On evaluation in the testing set (n = 5273), the neural network had a c-statistic of 0.823, calibration slope of 0.935, calibration intercept of 0.026, and Brier score of 0.0713. On decision curve analysis, the algorithm showed greater net benefit for changing management over all threshold probabilities than changing management on the basis of the American Society of Anesthesiologists classification alone or for all patients or for no patients. The model can be found here: https://sorg-apps.shinyapps.io/discdisposition/.CONCLUSIONSMachine learning algorithms show promising results on internal validation for preoperative prediction of nonroutine discharges. If found to be externally valid, widespread use of these algorithms via the open-access web application by healthcare professionals may help preoperative risk stratification of patients undergoing elective surgery for lumbar degenerative disc disorders.

An introduction and overview of machine learning in neurosurgical care.

BACKGROUND: Machine learning (ML) is a branch of artificial intelligence that allows computers to learn from large complex datasets without being explicitly programmed. Although ML is already widely manifest in our daily lives in various forms, the considerable potential of ML has yet to find its way into mainstream medical research and day-to-day clinical care. The complex diagnostic and therapeutic modalities used in neurosurgery provide a vast amount of data that is ideally suited for ML models. This systematic review explores ML's potential to assist and improve neurosurgical care. METHOD: A systematic literature search was performed in the PubMed and Embase databases to identify all potentially relevant studies up to January 1, 2017. All studies were included that evaluated ML models assisting neurosurgical treatment. RESULTS: Of the 6,402 citations identified, 221 studies were selected after subsequent title/abstract and full-text screening. In these studies, ML was used to assist surgical treatment of patients with epilepsy, brain tumors, spinal lesions, neurovascular pathology, Parkinson's disease, traumatic brain injury, and hydrocephalus. Across multiple paradigms, ML was found to be a valuable tool for presurgical planning, intraoperative guidance, neurophysiological monitoring, and neurosurgical outcome prediction. CONCLUSIONS: ML has started to find applications aimed at improving neurosurgical care by increasing the efficiency and precision of perioperative decision-making. A thorough validation of specific ML models is essential before implementation in clinical neurosurgical care. To bridge the gap between research and clinical care, practical and ethical issues should be considered parallel to the development of these techniques.

The endoscopic endonasal approach is not superior to the microscopic transcranial approach for anterior skull base meningiomas-a meta-analysis.

OBJECT: In the past decade, the endonasal transsphenoidal approach (eTSA) has become an alternative to the microsurgical transcranial approach (mTCA) for tuberculum sellae meningiomas (TSMs) and olfactory groove meningiomas (OGMs). The aim of this meta-analysis was to evaluate which approach offered the best surgical outcomes. METHODS: A systematic review of the literature from 2004 and meta-analysis were conducted in accordance with the PRISMA guidelines. Pooled incidence was calculated for gross total resection (GTR), visual improvement, cerebrospinal fluid (CSF) leak, intraoperative arterial injury, and mortality, comparing eTSA and mTCA, with p-interaction values. RESULTS: Of 1684 studies, 64 case series were included in the meta-analysis. Using the fixed-effects model, the GTR rate was significantly higher among mTCA patients for OGM (eTSA: 70.9% vs. mTCA: 88.5%, p-interaction < 0.01), but not significantly higher for TSM (eTSA: 83.0% vs. mTCA: 85.8%, p-interaction = 0.34). Despite considerable heterogeneity, visual improvement was higher for eTSA than mTCA for TSM (p-interaction < 0.01), but not for OGM (p-interaction = 0.33). CSF leak was significantly higher among eTSA patients for both OGM (eTSA: 25.1% vs. mTCA: 10.5%, p-interaction < 0.01) and TSM (eTSA: 19.3%, vs. mTCA: 5.81%, p-interaction < 0.01). Intraoperative arterial injury was higher among eTSA (4.89%) than mTCA patients (1.86%) for TSM (p-interaction = 0.03), but not for OGM resection (p-interaction = 0.10). Mortality was not significantly different between eTSA and mTCA patients for both TSM (p-interaction = 0.14) and OGM resection (p-interaction = 0.88). Random-effect models yielded similar results. CONCLUSION: In this meta-analysis, eTSA was not shown to be superior to mTCA for resection of both OGMs and TSMs.

The Timing of Tracheostomy and Outcomes After Aneurysmal Subarachnoid Hemorrhage: A Nationwide Inpatient Sample Analysis.

BACKGROUND: The goal of this study was to investigate the association of tracheostomy timing with outcomes after aneurysmal subarachnoid hemorrhage (SAH) in a national population. METHODS: Poor-grade aneurysmal SAH patients were extracted from the Nationwide Inpatient Sample (2002-2011). Multivariable linear regression was used to analyze predictors of tracheostomy timing and multivariable logistic regression was used to evaluate the association of timing of intervention with mortality, complications, and discharge to institutional care. Covariates included patient demographics, comorbidities, severity of subarachnoid hemorrhage (measured using the NIS-SAH severity scale), hospital characteristics, and other complications and length of stay. RESULTS: The median time to tracheostomy among 1380 poor-grade SAH admissions was 11 (interquartile range: 7-15) days after intubation. The mean number of days from intubation to tracheostomy in SAH patients at the hospital (p < 0.001) was the strongest predictor of tracheostomy timing for a patient, while comorbidities and SAH severity were not significant predictors. Mortality, neurologic complications, and discharge disposition did not differ significantly by tracheostomy time. However, later tracheostomy (when evaluated continuously) was associated with greater odds of pulmonary complications (p = 0.004), venous thromboembolism (p = 0.04), and pneumonia (p = 0.02), as well as a longer hospitalization (p < 0.001). Subgroup analysis only found these associations between tracheostomy timing and medical complications in patients with moderately poor grade (NIS-SAH severity scale 7-9), while there were no significant differences by timing of intervention in very poor-grade patients (NIS-SAH severity scale > 9). CONCLUSIONS: In this analysis of a large, national data set, variation in hospital practices was the strongest predictor of tracheostomy timing for an individual. In patients with moderately poor grade, later tracheostomy was independently associated with pulmonary complications, venous thromboembolism, pneumonia, and a longer hospitalization, but not with mortality, neurological complications, or discharge disposition. However, tracheostomy timing was not significantly associated with outcomes in very poor-grade patients.

Intracranial Pressure Monitoring-Review and Avenues for Development.

Intracranial pressure (ICP) monitoring is a staple of neurocritical care. The most commonly used current methods of monitoring in the acute setting include fluid-based systems, implantable transducers and Doppler ultrasonography. It is well established that management of elevated ICP is critical for clinical outcomes. However, numerous studies show that current methods of ICP monitoring cannot reliably define the limit of the brain's intrinsic compensatory capacity to manage increases in pressure, which would allow for proactive ICP management. Current work in the field hopes to address this gap by harnessing live-streaming ICP pressure-wave data and a multimodal integration with other physiologic measures. Additionally, there is continued development of non-invasive ICP monitoring methods for use in specific clinical scenarios.

Readmission After Aneurysmal Subarachnoid Hemorrhage: A Nationwide Readmission Database Analysis.

BACKGROUND AND PURPOSE: The goal of this nationwide study is to evaluate the suitability of readmission as a quality indicator in the aneurysmal subarachnoid hemorrhage (SAH) population. METHODS: Patients with aneurysmal SAH were extracted from the Nationwide Readmission Database (2013). Multivariable Cox proportional hazard regression was used to evaluate predictors of a 30-day readmission, and multivariable linear regression was used to analyze the association of hospital readmission rates with hospital mortality rates. Predictors screened included patient demographics, comorbidities, severity of SAH, complications from the SAH hospitalization, and hospital characteristics. RESULTS: The 30-day readmission rate was 10.2% (n=346) among the 3387 patients evaluated, and the most common reasons for readmission were neurological, hydrocephalus, infectious, and venous thromboembolic complications. Greater number of comorbidities, increased severity of SAH, and discharge disposition other than to home were independent predictors of readmission (P≤0.03). Although hydrocephalus during the SAH hospitalization was associated with readmission for the same diagnosis, other readmissions were not associated with having sustained the same complication during the SAH hospitalization. Hospital mortality rate was inversely associated with hospital SAH volume (P=0.03) but not significantly associated with hospital readmission rate; hospital SAH volume was also not associated with SAH readmissions. CONCLUSIONS: In this national analysis, readmission was primarily attributable to new medical complications in patients with greater comorbidities and severity of SAH rather than exacerbation of complications from the SAH hospitalization. Additionally, hospital readmission rates did not correlate with other established quality metrics. Therefore, readmission may be a suboptimal quality indicator in the SAH population.

Timing of Decompressive Hemicraniectomy for Stroke: A Nationwide Inpatient Sample Analysis.

BACKGROUND AND PURPOSE: Previous clinical trials were not designed to discern the optimal timing of decompressive craniectomy for stroke, and the ideal surgical timing in patients with space-occupying infarction who do not exhibit deterioration within 48 hours is debated. METHODS: Patients undergoing decompressive craniectomy for stroke were extracted from the Nationwide Inpatient Sample (2002-2011). Multivariable logistic regression evaluated the association of surgical timing with mortality, discharge to institutional care, and poor outcome (a composite end point including death, tracheostomy and gastrostomy, or discharge to institutional care). Covariates included patient demographics, comorbidities, year of admission, and hospital characteristics. However, standard stroke severity scales and infarct volume were not available. RESULTS: Among 1301 admissions, 55.8% (n=726) underwent surgery within 48 hours. Teaching hospital admission was associated with earlier surgery (P=0.02). The timing of intervention was not associated with in-hospital mortality. However, when evaluated continuously, later surgery was associated with increased odds of discharge to institutional care (odds ratio, 1.17; 95% confidence interval, 1.05-1.31, P=0.005) and of a poor outcome (odds ratio, 1.12; 95% confidence interval, 1.02-1.23; P=0.02). When evaluated dichotomously, the odds of discharge to institutional care and of a poor outcome did not differ at 48 hours after hospital admission, but increased when surgery was pursued after 72 hours. Subgroup analyses found no association of surgical timing with outcomes among patients who had not sustained herniation. CONCLUSION: s-In this nationwide analysis, early decompressive craniectomy was associated with superior outcomes. However, performing decompression before herniation may be the most important temporal consideration.

Validation of an International Classification of Disease, Ninth Revision coding algorithm to identify decompressive craniectomy for stroke.

BACKGROUND: Although International Classification of Disease, Ninth Revision, Clinical Modification (ICD9-CM) coding is the basis of administrative claims data, no study has validated an ICD9-CM algorithm to identify patients undergoing decompressive craniectomy for space-occupying supratentorial infarction. METHODS: Patients who underwent decompressive craniectomy for stroke at our institution were retrospectively identified and their associated ICD9-CM codes were extracted from billing data. An ICD9-CM algorithm was generated and its accuracy compared against physician review. RESULTS: A total of 10,925 neurosurgical operations were performed from December 2008 to March 2015, of which 46 (0.4%) were decompressive craniectomy for space-occupying stroke. The ICD9-CM procedure code for craniectomy (01.25) was only encoded in 67.4% of patients, while craniotomy (01.24) was used in 19.6% and lobectomy (01.39, 01.53, 01.59) in 13.1%. The ICD-9-CM algorithm included patients with a diagnosis codes for cerebral infarction (433.11, 434.01, 434.11, and 434.91) and a procedure code for craniotomy, craniectomy, or lobectomy. Patients were excluded with an ICD9-CM diagnosis code for brain tumor, intracranial abscess, subarachnoid hemorrhage, vertebrobasilar infarction, intracranial aneurysm, Moyamoya disease, intracranial venous sinus thrombosis, vertebral artery dissection, congenital cerebrovascular anomaly, head trauma or an ICD9-CM procedure code for laminectomy. This algorithm had a sensitivity of 97.8%, specificity of 99.9%, positive predictive value of 88.2%, and negative predictive value of 99.9%. The majority of false-positive results were patients who underwent evacuation of a primary intracerebral hematoma. CONCLUSION: An ICD-9-CM algorithm based on diagnosis and procedure codes can effectively identify patients undergoing decompressive craniectomy for supratentorial stroke.

Defensive medicine among neurosurgeons in the Netherlands: a national survey.

OBJECTIVE: In defensive medicine, practice is motivated by legal rather than medical reasons. Previous studies have analyzed the correlation between perceived medico-legal risk and defensive behavior among neurosurgeons in the United States, Canada, and South Africa, but not yet in Europe. The aim of this study is to explore perceived liability burdens and self-reported defensive behaviors among neurosurgeons in the Netherlands and compare their practices with their non-European counterparts. METHODS: A survey was sent to 136 neurosurgeons. The survey included questions from several domains: surgeon characteristics, patient demographics, type of practice, surgeon liability profile, policy coverage, defensive practices, and perception of the liability environment. Survey responses were analyzed and summarized. RESULTS: Forty-five neurosurgeons filled out the questionnaire (response rate of 33.1%). Almost half (n = 20) reported paying less than 5% of their income to annual malpractice premiums. Nearly all respondents view their insurance premiums as a minor or no burden (n = 42) and are confident that in their coverage is sufficient (n = 41). Most neurosurgeons (n = 38) do not see patients as "potential lawsuits". CONCLUSIONS: Relative to their American peers, Dutch neurosurgeons view their insurance premiums as less burdensome, their patients as a smaller legal threat, and their practice as less risky in general. They are sued less often and engage in fewer defensive behaviors than their non-European counterparts. The medico-legal climate in the Netherlands may contribute to this difference.

Thrombocytopenia and craniotomy for tumor: A National Surgical Quality Improvement Program analysis.

BACKGROUND: To the authors' knowledge, the current study is the first national analysis of the association between preoperative platelet count and outcomes after craniotomy. METHODS: Patients who underwent craniotomy for tumor were extracted from the prospective National Surgical Quality Improvement Program registry (2007-2014) and stratified by preoperative thrombocytopenia, defined as mild (125,000-149,000/µL), moderate (100,000-124,000/µL), severe (75,000-99,000/µL), or very severe (<75,000/µL). Cox proportional hazards analysis was used to evaluate the association between thrombocytopenia and 30-day mortality, and multivariable logistic regression with complications and unplanned reoperation. Covariates included patient age, sex, tumor histology, American Society of Anesthesiologists class, functional status, comorbidities, and surgical time. RESULTS: A total of 14,852 patients were included in the current study and thrombocytopenia was classified as mild in 4.4% (646 patients), moderate in 2.0% (290 patients), severe in 0.7% (105 patients), or very severe in 0.4% (66 patients) of patients. The adjusted hazard of 30-day death was significantly higher for patients with moderate (6.6%; hazard ratio [HR], 2.13 [95% confidence interval (95% CI), 1.30-3.49; P = 0.003]), severe (10.5%; HR, 2.33 [95% CI, 1.18-4.60; P = 0.02]), and very severe (10.6%; HR, 3.65 [95% CI, 1.71-7.82; P = 0.001]) thrombocytopenia, compared with patients without thrombocytopenia (2.9%), with an increased effect size noted with greater thrombocytopenia. Likewise, when the platelet count was evaluated continuously, a higher platelet count was associated with a lower hazard of 30-day mortality (HR, 0.987 [95% CI, 0.981-0.993; P<.001]), developing any complication (odds ratio, 0.985 [95% CI, 0.981-0.988; P<.001]), and reoperation (odds ratio, 0.990 [95% CI, 0.983-0.994; P = .003]). Unplanned reoperation was due to intracranial hemorrhage in 53.3% of patients with moderate thrombocytopenia. CONCLUSIONS: In this National Surgical Quality Improvement Program analysis, moderate and severe thrombocytopenia were associated with mortality and reoperation after craniotomy for tumor. Cancer 2016;122:1708-17. © 2016 American Cancer Society.

Thirty-day readmission and reoperation after surgery for spinal tumors: a National Surgical Quality Improvement Program analysis.

OBJECTIVE The goal of this study was to use a large national registry to evaluate the 30-day cumulative incidence and predictors of adverse events, readmissions, and reoperations after surgery for primary and secondary spinal tumors. METHODS Data from adult patients who underwent surgery for spinal tumors (2011-2014) were extracted from the prospective National Surgical Quality Improvement Program (NSQIP) registry. Multivariable logistic regression was used to evaluate predictors of reoperation, readmission, and major complications (death, neurological, cardiopulmonary, venous thromboembolism [VTE], surgical site infection [SSI], and sepsis). Variables screened included patient age, sex, tumor location, American Society of Anesthesiologists (ASA) physical classification, preoperative functional status, comorbidities, preoperative laboratory values, case urgency, and operative time. Additional variables that were evaluated when analyzing readmission included complications during the surgical hospitalization, hospital length of stay (LOS), and discharge disposition. RESULTS Among the 2207 patients evaluated, 51.4% had extradural tumors, 36.4% had intradural extramedullary tumors, and 12.3% had intramedullary tumors. By spinal level, 20.7% were cervical lesions, 47.4% were thoracic lesions, 29.1% were lumbar lesions, and 2.8% were sacral lesions. Readmission occurred in 10.2% of patients at a median of 18 days (interquartile range [IQR] 12-23 days); the most common reasons for readmission were SSIs (23.7%), systemic infections (17.8%), VTE (12.7%), and CNS complications (11.9%). Predictors of readmission were comorbidities (dyspnea, hypertension, and anemia), disseminated cancer, preoperative steroid use, and an extended hospitalization. Reoperation occurred in 5.3% of patients at a median of 13 days (IQR 8-20 days) postoperatively and was associated with preoperative steroid use and ASA Class 4-5 designation. Major complications occurred in 14.4% of patients: the most common complications and their median time to occurrence were VTE (4.5%) at 9 days (IQR 4-19 days) postoperatively, SSIs (3.6%) at 18 days (IQR 14-25 days), and sepsis (2.9%) at 13 days (IQR 7-21 days). Predictors of major complications included dependent functional status, emergency case status, male sex, comorbidities (dyspnea, bleeding disorders, preoperative systemic inflammatory response syndrome, preoperative leukocytosis), and ASA Class 3-5 designation (p < 0.05). The median hospital LOS was 5 days (IQR 3-9 days), the 30-day mortality rate was 3.3%, and the median time to death was 20 days (IQR 12.5-26 days). CONCLUSIONS In this NSQIP analysis, 10.2% of patients undergoing surgery for spinal tumors were readmitted within 30 days, 5.3% underwent a reoperation, and 14.4% experienced a major complication. The most common complications were SSIs, systemic infections, and VTE, which often occurred late (after discharge from the surgical hospitalization). Patients were primarily readmitted for new complications that developed following discharge rather than exacerbation of complications from the surgical hospital stay. The strongest predictors of adverse events were comorbidities, preoperative steroid use, and higher ASA classification. These models can be used by surgeons to risk-stratify patients preoperatively and identify those who may benefit from increased surveillance following hospital discharge.