Bibliometric Analysis and Applications of a Modified H-Index Examining the Research Productivity of Neurosurgery Faculty at High-Ranking Academic Institutions.

OBJECTIVE: A major critique of the h-index is that it may be inflated by noncritical authorship. We propose a modified h-index (hm), incorporating critical authorship, complementary to the h-index. We analyze its relationship to the traditional h-index, and how each varies across professional categories relevant to academic neurosurgery. This analysis is not meant to critique authorship decisions, affect career development, alter academic legacy, or imply that the concepts of team science or midlevel authorship contributions are not valuable. METHODS: H-indices and hms were gathered and computed for clinical neurosurgical faculty at the top 32 ranked academic neurosurgical programs based on the current literature. Hm was computed for faculty at each program, using articles in which the individual was first, second, last, or co-corresponding author. Individuals were further identified based on chair status, leadership status, neurosurgical subspecialty, and National Institutes of Health funding status. Further analysis was performed to determine factors influencing h-index and hm. RESULTS: The median h-index for the 225 physicians included in the final dataset is 48 (interquartile range [IQR], 39-61), whereas the median hm was 32 (IQR, 24-43). The median difference between h-index and hm is 15 (IQR, 10-23). The median hm/h was 64% (IQR, 57-74). National Institutes of Health funding and subspecialty (neurosurgical oncology, neurocritical care, and cerebrovascular) were associated with significant change from h to hm. CONCLUSIONS: The h-index can be influenced by noncritical authorship, and hm, using critical contributions, can be used as a complement reflecting critical academic output in neurosurgery. Leaders deciding on hiring or promotion should consider disparities in productivity predicated on noncritical authorship contributions.

Rapid Passive Gamma Mapping as an Adjunct to Electrical Stimulation Mapping for Functional Localization in Resection of Primary Brain Neoplasms.

OBJECTIVE: We examined the utility of passive high gamma mapping (HGM) as an adjunct to conventional awake brain mapping during glioma resection. We compared functional and survival outcomes before and after implementing intraoperative HGM. METHODS: This was a retrospective cohort study of 75 patients who underwent a first-time, awake craniotomy for glioma resection. Patients were stratified by whether their operation occurred before or after the implementation of a U.S. Food and Drug Administration-approved high-gamma mapping tool in July 2017. RESULTS: The preimplementation and postimplementation cohorts included 28 and 47 patients, respectively. Median intraoperative time (261 vs. 261 minutes, P = 0.250) and extent of resection (97.14% vs. 98.19%, P = 0.481) were comparable between cohorts. Median Karnofsky performance status at initial follow-up was similar between cohorts (P = 0.650). Multivariable Cox regression models demonstrated an adjusted hazard ratio for overall survival of 0.10 (95% confidence interval: 0.02-0.43, P = 0.002) for the postimplementation cohort relative to the preimplementation cohort. Progression-free survival adjusted for insular involvement showed an adjusted hazard ratio of 1.00 (95% confidence interval: 0.49-2.06, P = 0.999) following HGM implementation. Falling short of statistical significance, prevalence of intraoperative seizures and/or afterdischarges decreased after HGM implementation as well (12.7% vs. 25%, P = 0.150). CONCLUSIONS: Our results tentatively indicate that passive HGM is a safe and potentially useful adjunct to electrical stimulation mapping for awake cortical mapping, conferring at least comparable functional and survival outcomes with a nonsignificant lower rate of intraoperative epileptiform events. Considering the limitations of our study design and patient cohort, further investigation is needed to better identify optimal use cases for HGM.

Evaluating Surgical Cervical Arthrodesis With a Novel MRI Grading Score.

STUDY DESIGN: This was a single-institution retrospective study. OBJECTIVE: Evaluate a magnetic resonance imaging (MRI)-scoring system to differentiate arthrodesis from pseudoarthrosis following anterior cervical discectomy and fusion. SUMMARY OF BACKGROUND DATA: Diagnostic workup following fusion surgery often includes MRI to evaluate neural structures and computed tomography (CT) and/or dynamic x-rays to evaluate instrumentation and arthrodesis. The use of MRI alone for these evaluations would protect patients from harmful CT and x-ray ionizing radiation. METHODS: Neurosurgical attending evaluated CTs for arthrodesis or pseudoarthrosis. Blinded neuroradiology attending and neurosurgery senior resident evaluated independent T1 and T2 region of interest (ROI) signal intensity over instrumented disk space. Cerebral spinal fluid (CSF) at the cisterna magnum and distal adjacent uninstrumented vertebral body (VB) were also calculated. ROI interspace /ROI CSF and ROI interspace /ROI VB quotients were used to create T1- and T2-interspace interbody scores (IIS). RESULTS: Study population (n=64 patients, 50% female) with a mean age of 51.72 years and 109 instrumented levels with 45 fused levels (41.3%) were included. T1-weighted MRI, median T1-IIS CSF for arthrodesis was 176.20 versus 130.92 for pseudoarthrosis ( P <0.0001), T1-IIS VB for arthrodesis was 68.52 and pseudoarthrosis was 52.71 ( P <0.0001). T2-weighted MRI, median T2-IIS CSF for arthrodesis was 27.72 and 14.21 for pseudoarthrosis ( P <0.0001), while T2-IIS VB for arthrodesis was 67.90 and 41.02 for pseudoarthrosis ( P <0.0001). The greatest univariable discriminative capability for arthrodesis via AUROC was T1-IIS VB (0.7743). CONCLUSION: We describe a novel MRI scoring system that may help determine arthrodesis versus pseudoarthrosis following anterior cervical discectomy and fusion. Postoperative symptomatic patients may only require MRI, which would protect patients from ionizing radiation. LEVEL OF EVIDENCE: Level IV.

Defining the Clival Recess Surgical Corridor and Clival Classification System for Approach to Sellar Pathology.

BACKGROUND: Sellar masses within the pars intermedius, bordered anteriorly by normal pituitary gland/stalk, and/or with ectatic cavernous carotid anatomy are challenging and high risk when approached through the endonasal standard direct/anterior sellar approach. This approach portends itself to a higher risk of pituitary gland/stalk injury and subtotal resection with the aforementioned anatomic variants. OBJECTIVE: To describe the indirect clival recess corridor approach to sellar lesions. This corridor is a "silent" point of access to lesions in this region endoscopically. While skull base teams may have used this approach to some degree, it has not yet been described in the literature to our knowledge. METHODS: We defined the clival recess surgical corridor with skull base craniometric measurements and use a case example with aberrant anatomy to illustrate the approach. We cross-sectionally reviewed 42 patients with sellar and suprasellar masses. To describe the approach's anatomy, we devised and defined the terms dorsum sella plumb line, anatomic corridor, angle of osseous, and operative corridor. RESULTS: Created novel clival aeration grade informing surgical planning. Classified clival aeration as Grade 1 (100%-75% aeration), Grade 2 (75%-50% aeration), Grade 3 (50%-25% aeration), and Grade 4 (25%-0% aeration). This classification system determines extent of drilling of the clivus required to optimize the clival recess corridor approach and its limitations. CONCLUSION: The clival recess surgical corridor is effective for accessing pituitary lesions within the sella. Consider the indirect approach when a standard direct/anterior sellar approach has high risk for vascular injury and/or endocrinological dysfunction.

Optimal timing of radiotherapy following brain metastases surgery.

Background: There is growing evidence supporting the need for a short time delay before starting radiotherapy (RT) treatment postsurgery for most optimal responses. The timing of RT initiation and effects on outcomes have been evaluated in a variety of malignancies, but the relationship remains to be well established for brain metastasis. Methods: Retrospective study of 176 patients (aged 18-89 years) with brain metastases at a single institution (March 2009 to August 2018) who received RT following surgical resection. Time interval (≤22 and >22 days) from surgical resection to initiation of RT and any potential impact on patient outcomes were assessed. Results: Patients who underwent RT >22 days after surgical resection had a decreased risk for all-cause mortality of 47.2% (95% CI: 8.60, 69.5%). Additionally, waiting >40 days for RT after surgical resection more than doubled the risk of tumor progression; adjusted hazard ratio 2.02 (95% CI: 1.12, 3.64). Conclusions: Findings indicate that a short interval delay (>22 days) following surgical resection is required before RT initiation for optimal treatment effects in brain metastasis. Our timing of RT postsurgical resection data adds definition to current heterogeneity in RT timing, which is especially important for standardized clinical trial design and patient outcomes.

Corrigendum: Racial and Ethnic Inequities in Mortality During Hospitalization for Traumatic Brain Injury: A Call to Action.

[This corrects the article DOI: 10.3389/fsurg.2021.690971.].

Standardizing postoperative care for pediatric intradural Chiari decompressions to decrease length of stay.

OBJECTIVE: Amid national and local budget crises, cutting costs while maintaining quality care is a top priority. Chiari malformation is a relatively common pediatric neurosurgical pathology, and postoperative care varies widely. The postoperative course can be complicated by pain and nausea, which can extend the hospital stay. In this study, the authors aimed to examine whether instituting a standardized postoperative care protocol would decrease overall patient hospital length of stay (LOS) as well as cost to families and the hospital system. METHODS: A retrospective study of pediatric patients who underwent an intradural Chiari decompression with expansile duraplasty at a single institution from January 2016 to September 2019 was performed. A standardized postoperative care protocol was instituted on May 17, 2018. Pre- and postprotocol groups were primarily analyzed for demographics, LOS, and the estimated financial expense of the hospital stay. Secondary analysis included readmissions, opioid consumption, and follow-up. RESULTS: The analysis included 132 pediatric patients who underwent an intradural Chiari decompression with expansile duraplasty. The preprotocol group included 97 patients and the postprotocol group included 35 patients. Patient age ranged from 0.5 to 26 years (mean 9.5 years). The mean LOS preprotocol was 55.48 hours (range 25.90-127.77 hours), and the mean postprotocol LOS was 46.39 hours (range 27.58-77.38 hours). The comparison between means showed a statistically significant decrease following protocol initiation (95% CI 1.87-16.31 hours, p = 0.014). In the preprotocol group, 21 of 97 patients (22%) were discharged the first day after surgery compared with 14 of 35 patients (40%) in the postprotocol group (p = 0.045). The estimated cost of one night on the pediatric neurosurgical intermediate ward was approximately $4500, which gives overall cost estimates for 100 theoretical cases of $927,800 for the preprotocol group and $732,900 for the postprotocol group. CONCLUSIONS: By instituting a Chiari protocol, postoperative LOS was significantly decreased, which resulted in decreased healthcare costs while maintaining high-quality and safe care.

Racial and Ethnic Inequities in Mortality During Hospitalization for Traumatic Brain Injury: A Call to Action.

The health disparities which drive inequities in health outcomes have long plagued our already worn healthcare system and are often dismissed as being a result of social determinants of health. Herein, we explore the nature of these inequities by comparing outcomes for racial and ethnic minorities patients suffering from traumatic brain injury (TBI). We retrospectively reviewed all patients enrolled in the Trauma One Database at the Oregon Health & Science University Hospital from 2006 to October 2017 with an abbreviated injury scale (AIS) for the head or neck >2. Racial and ethnic minority patients were defined as non-White or Hispanic. A total of 6,352 patients were included in our analysis with 1,504 in the racial and ethnic minority cohort vs. 4,848 in the non-minority cohort. A propensity score (PS) model was generated to account for differences in baseline characteristics between these cohorts to generate 1,500 matched pairs. The adjusted hazard ratio for in-hospital mortality for minority patients was 2.21 [95% Confidence Interval (CI) 1.43-3.41, p < 0.001] using injury type, probability of survival, and operative status as covariates. Overall, this study is the first to specifically look at racial and ethnic disparities in the field of neurosurgical trauma. This research has demonstrated significant inequities in the mortality of TBI patients based on race and ethnicity and indicates a substantive need to reshape the current healthcare system and advocate for safer and more supportive pre-hospital social systems to prevent these life-threatening sequelae.

Changing Hands: A Rising Role of the Tumor Surgeon in Teaching Sylvian Fissure Dissection.

OBJECTIVE: The landscape of microneurosurgery has changed considerably over the past 2 decades, with a decline in indications for open surgery on cerebrovascular pathology and ever-increasing indications for open resection of brain tumors. This study investigated how these trends in case volume affected residents' training experiences in microsurgery and, specifically, Sylvian fissure dissection. METHODS: Resident case logs were reviewed, identifying open cerebrovascular operations and craniotomies for tumor. Operations involving Sylvian fissure dissection were identified through operative reports. Changes in case number by resident were plotted over time, and linear regression was applied. RESULTS: Among 23 chief residents, 3045 operations were identified, 1071 of which were for cerebrovascular pathology and 1974 for tumor. Open cerebrovascular experience decreased (P < 0.0001) while tumor volume remained unchanged (P = 0.221). The number of Sylvian fissure dissections per resident did not change over time overall (P = 0.583) or within cerebrovascular operations (P = 0.071). The number of Sylvian fissure dissections in tumor operations increased (P = 0.004). This effect was predominated by an increase in intraaxial tumors approached via Sylvian fissure dissection (P = 0.003). The proportion of Sylvian fissure dissections in tumor surgery increased from 15% in 2009 to 34% by 2019 (P = 0.003). CONCLUSIONS: Residents are seeing an increasing proportion of their Sylvian fissure dissection experience during tumor operations. The distribution of this experience will continue to evolve as surgical indications change but suggests a growing role for tumor surgeons in resident training in microsurgery.