The clinical utility of dual-energy CT in post-thrombectomy care: Part 2, the predictive value of contrast density and volume for delayed hemorrhagic transformation.

OBJECTIVES: Dual-energy CT allows differentiation between blood and iodinated contrast. This study aims to determine the predictive value of contrast density and volume on post-thrombectomy dual-energy CT for delayed hemorrhagic transformation and its impact on 90-day outcomes. MATERIALS AND METHODS: A retrospective analysis was performed on patients who underwent thrombectomy for anterior circulation large-vessel occlusion at a comprehensive stroke center from 2018-2021. Per institutional protocol, all patients underwent dual-energy CT immediately post-thrombectomy and MRI or CT 24 hours afterward. The presence of hemorrhage and contrast staining was evaluated by dual-energy CT. Delayed hemorrhagic transformation was determined by 24-hour imaging and classified into petechial hemorrhage or parenchymal hematoma using ECASS III criteria. Univariable and multivariable analyses were performed to determine predictors and outcomes of delayed hemorrhagic transformation. RESULTS: Of 97 patients with contrast staining and without hemorrhage on dual-energy CT, 30 and 18 patients developed delayed petechial hemorrhage and delayed parenchymal hematoma, respectively. On multivariable analysis, delayed petechial hemorrhage was predicted by anticoagulant use (OR,3.53;p=0.021;95%CI,1.19-10.48) and maximum contrast density (OR,1.21;p=0.004;95%CI,1.06-1.37;per 10 HU increase), while delayed parenchymal hematoma was predicted by contrast volume (OR,1.37;p=0.023;95%CI,1.04-1.82;per 10 mL increase) and low-density lipoprotein (OR,0.97;p=0.043;95%CI,0.94-1.00;per 1 mg/dL increase). After adjusting for potential confounders, delayed parenchymal hematoma was associated with worse functional outcomes (OR,0.07;p=0.013;95%CI,0.01-0.58) and mortality (OR,7.83;p=0.008;95%CI,1.66-37.07), while delayed petechial hemorrhage was associated with neither. CONCLUSION: Contrast volume predicted delayed parenchymal hematoma, which was associated with worse functional outcomes and mortality. Contrast volume can serve as a useful predictor of delayed parenchymal hematoma following thrombectomy and may have implications for patient management.

The clinical utility of dual-energy CT in post-thrombectomy care: Part 1, predictors and outcomes of subarachnoid and intraparenchymal hemorrhage.

OBJECTIVES: Dual-energy CT allows differentiation between blood and iodinated contrast. We aimed to determine predictors of subarachnoid and intraparenchymal hemorrhage on dual-energy CT performed immediately post-thrombectomy and the impact of these hemorrhages on 90-day outcomes. MATERIALS AND METHODS: A retrospective analysis was performed on patients who underwent thrombectomy for anterior circulation large-vessel occlusion and subsequent dual-energy CT at a comprehensive stroke center from 2018-2021. The presence of contrast, subarachnoid hemorrhage, or intraparenchymal hemorrhage immediately post-thrombectomy was assessed by dual-energy CT. Univariable and multivariable analyses were performed to identify predictors of post-thrombectomy hemorrhages and 90-day outcomes. Patients with unknown 90-day mRS were excluded. RESULTS: Of 196 patients, subarachnoid hemorrhage was seen in 17, and intraparenchymal hemorrhage in 23 on dual-energy CT performed immediately post-thrombectomy. On multivariable analysis, subarachnoid hemorrhage was predicted by stent retriever use in the M2 segment of MCA (OR,4.64;p=0.017;95%CI,1.49-14.35) and the number of thrombectomy passes (OR,1.79;p=0.019;95%CI,1.09-2.94;per an additional pass), while intraparenchymal hemorrhage was predicted by preprocedural non-contrast CT-based ASPECTS (OR,8.66;p=0.049;95%CI,0.92-81.55;per 1 score decrease) and preprocedural systolic blood pressure (OR,5.10;p=0.037;95%CI,1.04-24.93;per 10 mmHg increase). After adjusting for potential confounders, intraparenchymal hemorrhage was associated with worse functional outcomes (OR,0.25;p=0.021;95%CI,0.07-0.82) and mortality (OR,4.30;p=0.023,95%CI,1.20-15.36), while subarachnoid hemorrhage was associated with neither. CONCLUSIONS: Intraparenchymal hemorrhage immediately post-thrombectomy was associated with worse functional outcomes and mortality and can be predicted by low ASPECTS and elevated preprocedural systolic blood pressure. Future studies focusing on management strategies for patients presenting with low ASPECTS or elevated blood pressure to prevent post-thrombectomy intraparenchymal hemorrhage are warranted.

Conditional Vasospasm-Free Survival Following Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Following aneurysmal subarachnoid hemorrhage (SAH), patients are monitored closely for vasospasm in the intensive care unit. Conditional vasospasm-free survival describes the risk of future vasospasm as a function of time elapsed without vasospasm. Conditional survival has not been applied to this clinical scenario but could improve patient counseling and intensive care unit use. The objective of this study was to characterize conditional vasospasm-free survival following SAH. METHODS: This was a single institution, retrospective cohort study of patients treated for aneurysmal SAH between 1/1/2000-6/1/2020. The primary outcome was the development of vasospasm defined by the first instance of either radiographic vasospasm on computed tomography angiography, Lindegaard Index > 3.0 by transcranial doppler ultrasonography, or vasospasm-specific intraarterial therapy. Multivariable Cox regression was performed, and conditional vasospasm-free survival curves were constructed. RESULTS: A total of 528 patients were treated for aneurysmal SAH and 309 (58.5%) developed vasospasm. Conditional survival curves suggest patients who survive to postbleed day 10 without vasospasm have a nearly 90% chance of being discharged without vasospasm. The median onset of vasospasm was postbleed day 6. Age more than 50 years was associated with a lower risk (hazard ratio [HR] = .76; 95% confidence interval [CI] 0.64-0.91; p < 0.001). Higher initial systolic blood pressure (HR = 1.18; 95% CI 1.046-1.350; p = .008), Hunt-Hess grades 4 or 5 (HR = 1.304; 95% CI 1.014-1.676), and modified Fisher scale score of 4 (HR = 1.808; 95% CI 1.198-2.728) were associated with higher vasospasm than the respective lower grades. CONCLUSION: Conditional survival provides a useful framework for counseling patients and making decisions around vasospasm risk for patients with aneurysmal SAH, while risk factor-stratified plots facilitate a patient-centric, evidence-based approach to these conversations and decisions.

Creation and Validation of a Stroke Scale to Increase Utility of National Inpatient Sample Administrative Data for Clinical Stroke Research.

INTRODUCTION: The National Inpatient Sample (NIS) has led to several breakthroughs via large sample size. However, utility of NIS is limited by the lack of admission NIHSS and 90-day modified Rankin score (mRS). This study creates estimates for stroke severity at admission and 90-day mRS using NIS data for acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT). METHODS: Three patient cohorts undergoing MT for AIS were utilized: Cohort 1 (N = 3729) and Cohort 3 (N = 1642) were derived from NIS data. Cohort 2 (N=293) was derived from a prospectively-maintained clinical registry. Using Cohort 1, Administrative Stroke Outcome Variable (ASOV) was created using disposition and mortality. Factors reflective of stroke severity were entered into a stepwise logistic regression predicting poor ASOV. Odds ratios were used to create the Administrative Data Stroke Scale (ADSS). Performances of ADSS and ASOV were tested using Cohort 2 and compared with admission NIHSS and 90-day mRS, respectively. ADSS performance was compared with All Patient Refined-Diagnosis Related Group (APR-DRG) severity score using Cohort 3. RESULTS: Agreement of ASOV with 90-day mRS > 2 was fair (κ = 0.473). Agreement with 90-day mRS > 3 was substantial (κ = 0.687). ADSS significantly correlated (p < 0.001) with clinically-significant admission NIHSS > 15. ADSS performed comparably (AUC = 0.749) to admission NIHSS (AUC = 0.697) in predicting 90-day mRS > 2 and mRS > 3 (AUC = 0.767, 0.685, respectively). ADSS outperformed APR-DRG severity score in predicting poor ASOV (AUC = 0.698, 0.682, respectively). CONCLUSION: We developed and validated measures of stroke severity at admission (ADSS) and outcome (ASOV, estimate for 90-day mRS > 3) to increase utility of NIS data in stroke research.

Neighborhood Socioeconomic Status and Mechanical Thrombectomy Outcomes.

BACKGROUND/PURPOSE: Our study aimed to assess the impacts of neighborhood socioeconomic status on mechanical thrombectomy (MT) outcomes for acute ischemic stroke (AIS). METHODS: We conducted a prospective observational study of consecutive adult AIS patients treated with MT at one US comprehensive stroke center from 2012 to 2018. A composite neighborhood socioeconomic score (nSES) was created using patient home address, median household income, percentage of households with interest, dividend, or rental income, median value of housing units, percentage of persons 25 or older with high school degrees, college degrees or holding executive, managerial or professional specialty occupations. Using this score, patients were divided into low, middle and high nSES tertiles. Outcomes included 90-day functional independence, in-hospital mortality, length of hospital stay, discharge location, time to recanalization, successful recanalization, and symptomatic intracranial hemorrhage (sICH). RESULTS: 328 patients were included. Between the three nSES groups, proportion of White patients, time-to-recanalization and admission NIH stroke scale differed significantly (p<0.05). Patients in the high nSES tertile were more likely to be functionally dependent at 90 days (unadjusted OR, 95% CI, 1.91 [1.10, 3.36]) and were less likely to die in the hospital (unadjusted OR, 95% CI, 0.46, [0.20, 0.98]). Further, patients in the high nSES tertile had decreased times to recanalization (median time in minutes, low=335, mid=368, high=297, p=0.04). However, after adjusting for variance in race and severity of stroke, the differences in clinical outcomes were not significant. CONCLUSION: This study highlights how unadjusted neighborhood socioeconomic status is significantly associated with functional outcome, mortality, and time-to-recanalization following MT for AIS. Since adjustment modifies the significant association, the socioeconomic differences may be influenced by differences in pre-hospital factors that drive severity of stroke and time to recanalization. Better understanding of the interplay of these factors may lead to timelier evaluation and improvement in patient outcomes.

CYP2C19 Loss-of-Function is Associated with Increased Risk of Ischemic Stroke after Transient Ischemic Attack in Intracranial Atherosclerotic Disease.

OBJECTIVES: Intracranial atherosclerotic disease (ICAD) is responsible for 8-10% of acute ischemic strokes, and resistance to antiplatelet therapy is prevalent. CYP2C19 gene loss-of-function (up to 45% of patients) causes clopidogrel resistance. For patients with asymptomatic ICAD and ICAD characterized by transient ischemic attack (TIA), this study measures the effect of CYP2C19 loss-of-function on ischemic stroke risk during clopidogrel therapy. MATERIALS AND METHODS: From a deidentified database of medical records, patients were selected with ICD-9/10 code for ICAD, availability of CYP2C19 genotype, clopidogrel exposure, and established patient care. Dual-antiplatelet therapy patients were included. Patients with prior ischemic stroke, other neurovascular condition, intracranial angioplasty/stenting, or observation time <1 month were excluded. Time-to-event analysis using Cox regression was conducted to model first-time ischemic stroke events based on CYP2C19 loss-of-function allele and adjusted for age, gender, race, length of aspirin, length of concurrent antiplatelet/anticoagulant treatment, diabetes, coagulopathy, hypertension, heart disease, atrial fibrillation, and lipid disorder. Subset analyses were performed for asymptomatic and post-TIA subtypes of ICAD. RESULTS: A total of 337 patients were included (median age 68, 58% male, 88% Caucasian, 26% CYP2C19 loss-of-function). A total of 161 (47.8%) patients had TIA at time of ICAD diagnosis, while 176 (52.2%) were asymptomatic. First-time ischemic stroke was observed among 20 (12.4%) post-TIA ICAD patients and 17 (9.7%) asymptomatic ICAD patients. Median observation time was 2.82 [IQR 1.13-5.17] years. CYP2C19 loss-of-function allele was associated with ischemic stroke event (HR 2.2, 95% CI 1.1-4.3, p=0.020) after adjustment. Post-TIA ICAD patients had a higher risk of ischemic stroke from CYP2C19 loss-of-function (HR 3.4, 95% CI 1.4-8.2, p=0.006). CONCLUSIONS: CYP2C19 loss-of-function was associated with 3-fold increased risk of first-time ischemic stroke for ICAD patients treated with clopidogrel after TIA. This effect was not observed for asymptomatic ICAD. CYP2C19-guided antiplatelet selection may improve stroke prevention in ICAD after TIA.

Mechanical Thrombectomy in Patients With Ischemic Stroke With Prestroke Disability.

Background and Purpose- We aimed to compare functional and procedural outcomes of patients with acute ischemic stroke with none-to-minimal (modified Rankin Scale [mRS] score, 0-1) and moderate (mRS score, 2-3) prestroke disability treated with mechanical thrombectomy. Methods- Consecutive adult patients undergoing mechanical thrombectomy for an anterior circulation stroke were prospectively identified at 2 comprehensive stroke centers from 2012 to 2018. Procedural and 90-day functional outcomes were compared among patients with prestroke mRS scores 0 to 1 and 2 to 3 using χ2, logistic, and linear regression tests. Primary outcome and significant differences in secondary outcomes were adjusted for prespecified covariates. Results- Of 919 patients treated with mechanical thrombectomy, 761 were included and 259 (34%) patients had moderate prestroke disability. Ninety-day mRS score 0 to 1 or no worsening of prestroke mRS was observed in 36.7% and 26.7% of patients with no-to-minimal and moderate prestroke disability, respectively (odds ratio, 0.63 [0.45-0.88], P=0.008; adjusted odds ratio, 0.90 [0.60-1.35], P=0.6). No increase in the disability at 90 days was observed in 22.4% and 26.7%, respectively. Rate of symptomatic intracerebral hemorrhage (7.3% versus 6.2%, P=0.65), successful recanalization (86.7% versus 83.8%, P=0.33), and median length of hospital stay (5 versus 5 days, P=0.06) were not significantly different. Death by 90 days was higher in patients with moderate prestroke disability (14.3% versus 40.3%; odds ratio, 4.06 [2.82-5.86], P<0.001; adjusted odds ratio, 2.83 [1.84, 4.37], P<0.001). Conclusions- One-third of patients undergoing mechanical thrombectomy had a moderate prestroke disability. There was insufficient evidence that functional and procedural outcomes were different between patients with no-to-minimal and moderate prestroke disability. Patients with prestroke disability were more likely to die by 90 days.

Mechanical Thrombectomy in Ischemic Stroke Patients with Severe Pre-Stroke Disability.

Frequency and outcomes of mechanical thrombectomy (MT) in clinical practice for patients with severe pre-stroke disability are largely unknown. In this case series, we aim to describe the disability make-up and outcomes of 33 patients with severe pre-stroke disability undergoing MT. Patients with a permanent, severe, pre-stroke disability (modified Rankin Score, mRS, 4-5) were identified from a prospectively-maintained database of consecutive, MT-treated, anterior circulation acute ischemic stroke patients at two comprehensive stroke centers in the United States. We present details on the cause of disability and socio-demographic status as well as procedural and functional outcomes. This study, despite the lack of inferential testing due to limited sample size, provides insight into demographics and outcomes of MT-treated patients with severe pre-stroke disability. Rate of return to functional baseline as well as rates of procedural success and complications were comparable to that reported in the literature for patients without any pre-existing disability.

Preoperative Use of Statins in Carotid Artery Stenting: A Systematic Review and Meta-analysis.

PURPOSE: To determine through meta-analysis whether administration of statins before carotid artery stenting (CAS) is associated with fewer periprocedural adverse events. METHODS: All randomized and observational English-language studies of periprocedural statin administration prior to CAS that reported the outcomes of interest (stroke, transient ischemic attack, myocardial infarction, and death at 30 days) were included in a random-effects meta-analysis. The I2 statistic was used to assess heterogeneity. Meta-regression analysis was performed to determine whether an association of statin treatment with risk of outcome events was influenced by other trial-level baseline characteristics of statin-treated and untreated patients. RESULTS: Eleven studies comprising 4088 patients were included. Patients who received statins prior to CAS had a significantly lower risk of stroke (OR 0.39, 95% CI 0.27 to 0.58, p<0.01; I2=0%) and death (OR 0.30, 95% CI 0.10 to 0.96, p=0.042; I2=0%). Statin use was not associated with a reduced risk of transient ischemic attack or myocardial infarction. In meta-regression analysis, other trial-level baseline characteristics had no significant influence on the association of statin treatment with death or stroke. CONCLUSION: Statin therapy prior to CAS is associated with decreased risk of perioperative stroke and death without any effect on the rates of transient ischemic attack or myocardial infarction.

Mechanical Thrombectomy Outcomes With and Without Intravenous Thrombolysis in Stroke Patients: A Meta-Analysis.

BACKGROUND AND PURPOSE: Whether prior intravenous thrombolysis provides any additional benefits to the patients undergoing mechanical thrombectomy for large vessel, acute ischemic stroke remains unclear. METHODS: We conducted a meta-analysis of 13 studies obtained through PubMed and EMBASE database searches to determine whether functional outcome (modified Rankin Scale) at 90 days, successful recanalization rate, and symptomatic intracerebral hemorrhage rate differed between patients who underwent mechanical thrombectomy with (MT+IVT) and without (MT-IVT) pre-treatment with intravenous thrombolysis. RESULTS: MT+IVT patients compared with MT-IVT patients had better functional outcomes (modified Rankin Scale score, 0-2; summary odds ratio [OR], 1.27 [95% confidence interval (CI), 1.05-1.55]; P=0.02; n=1769/1174), lower mortality (OR, 0.71 [95% CI, 0.55-0.91]; P=0.006; n=1774/1202), and higher rate of successful recanalization (OR, 1.46 [95% CI, 1.09-1.96]; P=0.01; n=1652/1216) without having increased odds of symptomatic intracerebral hemorrhage (OR, 1.11 [95% CI, 0.69-1.77]; P=0.67; n=1471/1143). A greater number of MT+IVT patients required ≤2 passes with a neurothrombectomy device to achieve successful recanalization (OR, 2.06 [95% CI, 1.37-3.10]; P=0.0005; n=316/231). CONCLUSIONS: Our results demonstrated that MT+IVT patients had better functional outcomes, lower mortality, higher rate of successful recanalization, requiring lower number of device passes, and equal odds of symptomatic intracerebral hemorrhage compared with MT-IVT patients. The results support the current guidelines of offering intravenous thrombolysis to eligible patients even if they are being considered for mechanical thrombectomy. Because the data are compiled from studies where the 2 groups differed based on eligibility for intravenous thrombolysis, randomized trials are necessary to accurately evaluate the added value of intravenous thrombolysis in patients treated with mechanical thrombectomy.

Corticosteroids in the Management of Hyponatremia, Hypovolemia, and Vasospasm in Subarachnoid Hemorrhage: A Meta-Analysis.

BACKGROUND: Cerebral vasospasm and sodium and fluid imbalances are common sequelae of aneurysmal subarachnoid hemorrhage (SAH) and cause of significant morbidity and mortality. Studies have shown the benefit of corticosteroids in the management of these sequelae. We have reviewed the literature and analyzed the available data for corticosteroid use after SAH. METHODS: PubMed, EMBASE, and Cochrane electronic databases were searched without language restrictions, and 7 observational, controlled clinical studies of the effect of corticosteroids in the management of SAH patients were identified. Data on sodium and fluid balances, symptomatic vasospasm (SVS), and outcomes were pooled for meta-analyses using the Mantel-Haenszel random effects model. RESULTS: Corticosteroids, specifically hydrocortisone and fludrocortisone, decreased natriuretic diuresis and incidence of hypovolemia. Corticosteroid administration is associated with lower incidence of SVS in the absence of nimodipine, but does not alter the neurological outcome. CONCLUSIONS: Supplementation of corticosteroids with mineralocorticoid activity, such as hydrocortisone or fludrocortisone, helps in maintaining sodium and volume homeostasis in SAH patients. Larger trials are warranted to confirm the effects of corticosteroids on SVS and patient outcomes.

"Home Field Advantage": The Presence of a "Home" Neurosurgical Residency Training Program is Associated With Improved Match Outcomes.

BACKGROUND AND OBJECTIVES: Competition for neurosurgical residency training positions remains fierce. The support provided by applicants' home neurosurgery residency training programs (NRTP) is suspected to play a key role in the National Resident Matching Program (NRMP) process. We sought to evaluate the impact of the presence of an Accreditation Council for Graduate Medical Education-accredited NRTP at medical students' home institutions has on NRMP match outcomes. METHODS: Our cross-sectional observational study examined all US allopathic senior student Electronic Residency Application Service applications to a single NRTP from 2016 to 2022. RESULTS: We analyzed a total of 1650 Electronic Residency Application Service applications to a single NRTP, of which 1432 (86.8%) were from schools with an Accreditation Council for Graduate Medical Education-accredited NRTP (NRTP+) and 218 (13.2%) were from schools without a residency (NRTP-). NRTP+ applicants matched a higher rate on both pooled analysis (80.8% vs 71.6%, P = .002) and paired analysis (P = .02) over the seven-cycle study period. This difference was present before (82.4% vs 73.9%, P = .01) and after (77.2% vs 65.6%, P = .046) the COVID-19 pandemic. Cohorts were overall similar; however, NRTP+ applicants had more publication experiences (19.6 ± 19.0 vs 13.1 ± 10.2, P < .001) and were more likely to complete a research gap year (RGY) (25.8% vs 17.0%, P = .004). Completing a RGY was associated with an increased likelihood of matching for NRTP+ applicants but not for NRTP- applicants: NRTP+: 84.9% vs 78.1% (P = .0056); NRTP-: 70.3% vs 70.9% (P = .94). CONCLUSION: The presence of a NRTP at a medical student's home institution is associated with improved NRMP match outcomes. This held true both before and after the COVID-19 pandemic. Applicants from schools with a NRTP had more publication experiences and were more likely to complete a RGY. Completion of a RGY is associated with an increased likelihood of matching only for students with an affiliated NRTP.

Predictors of acute post-thrombectomy intracranial hemorrhage expansion in anterior circulation infarcts.

BACKGROUND: Post-mechanical thrombectomy (MT) intracranial hemorrhage (ICH) is a major source of morbidity in treated acute ischemic stroke patients with large vessel occlusion. ICH expansion may further contribute to morbidity. We sought to identify factors associated with ICH expansion on imaging evaluation post-MT. METHODS: We performed a retrospective cohort study of patients undergoing MT at a single comprehensive stroke center. Per protocol, patients underwent dual-energy head CT (DEHCT) post-MT followed by a 24-h interval non-contrast enhanced MRI. ICH expansion was defined as any increase in blood volume between the two studies if identified on the DEHCT. Univariate and multivariable analyses were performed to identify risk factors for ICH expansion. RESULTS: ICH was identified on DEHCT in 13% of patients (n = 35/262), with 20% (7/35) demonstrating expansion on interval MRI. The average increase in blood volume was 11.4 ml (SD 6.9). Univariate analysis identified anticoagulant usage (57% vs 14%, p = 0.03), petechial hemorrhage inside the infarct margins or intraparenchymal hematoma on DEHCT (ECASS-II HI2/PH1/PH2) (71% vs 14%, p < 0.01), basal ganglia hemorrhage (71% vs 21%, p = 0.02), and basal ganglia infarction (86% vs 32%, p = 0.03) as factors associated with ICH expansion. Multivariate regression demonstrated that anticoagulant usage (OR 20.3, 95% C.I. 2.43-446, p < 0.05) and ECASS II scores of HI2/PH1/PH2 (OR 11.7, 95% C.I. 1.24-264, p < 0.05) were significantly predictive of ICH expansion. CONCLUSION: Expansion of post-MT ICH on 24-h interval MRI relative to immediate post-thrombectomy DEHCT is significantly associated with baseline anticoagulant usage and petechial hemorrhage inside the infarct margins or presence of intraparenchymal hematoma (ECASS-II HI2/PH1/PH2).

Low Levels of Low-Density Lipoprotein Cholesterol Increase the Risk of Post-Thrombectomy Delayed Parenchymal Hematoma.

PURPOSE: Low levels of low-density lipoprotein cholesterol (LDL-C) have been suggested to increase the risk of hemorrhagic transformation (HT) following acute ischemic stroke. However, the literature on the relationship between LDL-C levels and post-thrombectomy HT is sparse. The aim of our study is to investigate the association between LDL-C and delayed parenchymal hematoma (PH) that was not seen on immediate post-thrombectomy dual-energy computed tomography (DECT). MATERIALS AND METHODS: A retrospective analysis was conducted on all patients with anterior circulation large vessel occlusion who underwent thrombectomy at a comprehensive stroke center from 2018-2021. Per institutional protocol, all patients received DECT immediately post-thrombectomy and magnetic resonance imaging or CT at 24 hours. The presence of immediate hemorrhage was assessed by DECT, while delayed PH was assessed by 24-hour imaging. Multivariable analysis was performed to identify predictors of delayed PH. Patients with hemorrhage on immediate post-thrombectomy DECT were excluded to select only those with delayed PH. RESULTS: Of 159 patients without hemorrhage on immediate post-thrombectomy DECT, 18 (11%) developed delayed PH on 24-hour imaging. In multivariable analysis, LDL-C (odds ratio [OR], 0.76; P=0.038; 95% confidence interval [CI], 0.59-0.99; per 10 mg/dL increase) independently predicted delayed PH. High-density lipoprotein cholesterol, triglyceride, and statin use were not associated. After adjusting for potential confounders, LDL-C ≤50 mg/dL was associated with an increased risk of delayed PH (OR, 5.38; P=0.004; 95% CI, 1.70-17.04), while LDL-C >100 mg/dL was protective (OR, 0.26; P=0.041; 95% CI, 0.07-0.96). CONCLUSION: LDL-C ≤50 mg/dL independently predicted delayed PH following thrombectomy and LDL-C >100 mg/dL was protective, irrespective of statin. Thus, patients with low LDL-C levels may warrant vigilant monitoring and necessary interventions, such as blood pressure control or anticoagulation management, following thrombectomy even in the absence of hemorrhage on immediate post-thrombectomy DECT.

Trends in utilization of standardized letters of recommendation in the 2021-2022 neurosurgery application process.

OBJECTIVE: Standardized letters of recommendation (SLORs) were introduced during the 2020-2021 neurosurgery residency application cycle, but suffered from poor interrater reliability and grade inflation. Changes were made to the SLOR template and utilization patterns in response to these shortcomings. The authors examined the second year of SLOR utilization. They hypothesized that grade inflation and interrater reliability would be improved from the first iteration. They also hypothesized that increased numbers of letters by single writers would correlate with broader rating distributions. METHODS: This cross-sectional study analyzed all SLORs submitted to a single neurosurgery residency program over the 2021-2022 cycle. Data from 7 competency domains and the overall rating were recorded and stratified by academic category of the letter writer. Interrater reliability was evaluated using Krippendorff's alpha. The frequency of letters written was evaluated using the Kruskal-Wallis H test. RESULTS: Ninety percent of SLORs rated applicants among the top 25%, but there was a significant decrease in the usage of the top 1% and top 2%-5% ratings. Interrater reliability was poor across all competencies. Writers who completed 1 SLOR rated applicants higher and had a narrower range than those who completed multiple SLORs. CONCLUSIONS: Changes in the format and subsequent utilization patterns of SLORs have slightly decreased grade inflation; however, interrater reliability remains poor. The most wide-ranging evaluators submitted the highest number of SLORs, suggesting that future evaluation and usage of SLORs should emphasize letter-writer characteristics and numbers of SLORs written. Overall, SLORs have been well and broadly accepted with subtle improvements in the second year of utilization.

Words matter: using natural language processing to predict neurosurgical residency match outcomes.

OBJECTIVE: Narrative letters of recommendation (NLORs) are considered by neurosurgical program directors to be among the most important parts of the residency application. However, the utility of these NLORs in predicting match outcomes compared to objective measures has not been determined. In this study, the authors compare the performance of machine learning models trained on applicant NLORs and demographic data to predict match outcomes and investigate whether narrative language is predictive of standardized letter of recommendation (SLOR) rankings. METHODS: This study analyzed 1498 NLORs from 391 applications submitted to a single neurosurgery residency program over the 2020-2021 cycle. Applicant demographics and match outcomes were extracted from Electronic Residency Application Service applications and training program websites. Logistic regression models using least absolute shrinkage and selection operator were trained to predict match outcomes using applicant NLOR text and demographics. Another model was trained on NLOR text to predict SLOR rankings. Model performance was estimated using area under the curve (AUC). RESULTS: Both the NLOR and demographics models were able to discriminate similarly between match outcomes (AUCs 0.75 and 0.80; p = 0.13). Words including "outstanding," "seamlessly," and "AOA" (Alpha Omega Alpha) were predictive of match success. This model was able to predict SLORs ranked in the top 5%. Words including "highest," "outstanding," and "best" were predictive of the top 5% SLORs. CONCLUSIONS: NLORs and demographic data similarly discriminate whether applicants will or will not match into a neurosurgical residency program. However, NLORs potentially provide further insight regarding applicant fit. Because words used in NLORs are predictive of both match outcomes and SLOR rankings, continuing to include narrative evaluations may be invaluable to the match process.

The cost of a plastic surgery team assisting with cranioplasty.

OBJECTIVES: Cranioplasty is a commonly performed neurosurgical procedure that restores cranial anatomy. While plastic surgeons are commonly involved with cranioplasties, the cost of performing a cranioplasty with neurosurgery alone (N) vs. neurosurgery and plastic surgery (N + P) is unknown. METHODS: A single-center, multi-surgeon, retrospective cohort study was undertaken on all cranioplasties performed from 2012 to 22. The primary exposure variable of interest was operating team, comparing N vs. N + P. Cost data was inflation-adjusted to January 2022 using Healthcare Producer Price Index as calculated by the US Bureau of Labor Statistics. RESULTS: 186 patients (105 N vs. 81 N + P) underwent cranioplasties. The N + P group has a significantly longer length-of-stay (LOS) 4.5 ± 1.6days, vs. 6.0 ± 1.3days (p < 0.001), but no significant difference in reoperation, readmission, sepsis, or wound breakdown. N was significantly less expensive than N + P during both the initial cranioplasty cost ($36,739 ± $4592 vs. $41,129 ± $4374, p 0.014) and total cranioplasty costs including reoperations ($38,849 ± $5017 vs. $53,134 ± $6912, p < 0.001). Univariable analysis (threshold p = 0.20) was performed to justify inclusion into a multivariable regression model. Multivariable analysis for initial cranioplasty cost showed that sepsis (p = 0.024) and LOS (p = 0.003) were the dominant cost contributors compared to surgeon type (p = 0.200). However, surgeon type (N vs. N + P) was the only significant factor (p = 0.011) for total cost including revisions. CONCLUSIONS: Higher costs to N + P involvement without obvious change in outcomes were found in patients undergoing cranioplasty. Although other factors are more significant for the initial cranioplasty cost (sepsis, LOS), surgeon type proved the independent dominant factor for total cranioplasty costs, including revisions.

Impact of neurovascular comorbidities and complications on outcomes after procedural management of arteriovenous malformations.

OBJECTIVE: Cerebral arteriovenous malformations (AVMs) are complex vascular lesions at perpetual risk for rupture, which can lead to significant morbidity and mortality. This study sought to evaluate the dynamic relationship between comorbidities and post-procedure complications to quantify the risk of poor discharge outcomes to create a predictive outcomes model. METHODS: The National Inpatient Sample (NIS) data from 2012 to 2015 was queried for AVM treatment using International Classification of Diseases, Ninth Revision codes. The Neurovascular Comorbidities Index (NCI) quantified patient comorbidity burden. In-hospital complications included surgical and medical complications or seizures. The primary outcome was the NIS Subarachnoid Hemorrhage Outcome Measure (NIS-SOM). RESULTS: A total of 1363 patients were included. A total of 1330 patients (98%) underwent embolization, 28 (2%) underwent resection, and 9 (0.7%) underwent radiosurgery. A higher NCI was associated with the occurrence of any complication (odds ratio [OR], 1.30 if NCI = 2; P < 0.001). Higher NCI was also significantly associated with a poor NIS-SOM outcome (OR, 2.45 if NCI = 2 and no complications; P < 0.001). A ruptured AVM with intracranial hemorrhage (ICH) increased the risk of in-hospital complications (OR, 2.16; P = 0.007) and a poor NIS-SOM outcome (OR, 3.18; P < 0.001). Various hypothetical patient scenarios and the predicted outcomes are also presented. CONCLUSION: Neurovascular comorbidities have a significant impact on poor functional outcomes at discharge in patients with and without complications following procedural management of AVMs. At the time of initial patient assessment, risk stratification strategies should take into account neurovascular comorbidities and potential complications. Such an approach would ultimately optimize patient outcomes and increase the value of care provided.

Does Plastic Surgery Involvement Decrease Complications After Cranioplasty? A Retrospective Cohort Study.

OBJECTIVES: To compare postoperative outcomes after cranioplasties performed by neurosurgery only (N) versus neurosurgery and plastic surgery combined (N+P). METHODS: A single-center, multisurgeon, retrospective cohort study was undertaken on all cranioplasties performed from November 2006 to December 2021. The primary exposure variable was operating team (N vs. N+P). The primary outcome was the need for reoperation. Secondary outcomes included surgical site infections, complications, length of stay (LOS), and length of drain placement. RESULTS: Of 188 patients undergoing cranioplasty during the study period, 106 (56%) patients were in the N group, and 82 (44%) were in the N+P group. Patient demographics were similar between the 2 groups. For the primary outcome, a total of 20 (18.9%) reoperations were seen in the N group, and 13 (15.9%) in the N+P group (P = 0.708). However, the median time to reoperation was slightly longer in the N+P group in the survival analysis. Wound dehiscence (1.9% vs. 3.7%, P = 0.454), surgical site infection (5.7% vs. 9.8%, P = 0.289), and complication rate (30.2% vs. 32.9%, P = 0.688) did not differ between the 2 groups. Furthermore, the N group had less Jackson-Pratt drain use (58.5% vs. 85.4%, P < 0.001), earlier drain removal (1.9 ± 1.6 vs. 3.4 ± 3.9 days, P < 0.001), and shorter LOS (3.8 ± 5.9 vs. 4.7 ± 3.9 days, P < 0.001). On multivariate regression analysis controlling for age, body mass index, smoking, craniectomy type, reason for craniectomy, and graft type, N+P was associated with increased drain use (odds ratio = 4.90, 95% confidence interval 2.28-11.30, P < 0.001) and longer drain duration (ß = 1.50, 95% confidence interval 0.43-2.60, P = 0.007). CONCLUSIONS: Despite similar complication and reoperation rates between groups, reoperations in the N group occurred sooner, whereas the N+P group more commonly used drains and kept drains in for longer.