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Background: Incontrovertible predictors of shunt malfunction remain elusive., Objective: To determine predictors of shunt failure within 30 d of index surgery., Methods: This was a single-center retrospective cohort study from January 2010 through November 2016. Using a ventricular shunt surgery research database, clinical and procedural variables were procured. An "index surgery" was defined as implantation of a new shunt or revision or augmentation of an existing shunt system. The primary outcome was shunt failure of any kind within the first 30 days of index surgery. Bivariate models were created, followed by a final multivariable logistic regression model using a backward-forward selection procedure., Results: Our dataset contained 655 unique patients with a total of 1206 operations. The median age for the cohort at the time of first shunt surgery was 4.6 yr (range, 0-28; first and third quartile, .37 and 11.8, respectively). The 30-day failure rates were 12.4% when analyzing the first-index operation only (81/655), and 15.7% when analyzing all-index operations (189/1206). Small or slit ventricles at the time of index surgery and prior ventricular shunt operations were found to be significant covariates in both the "first-index" (P < .01 and P = .05, respectively) and "all-index" (P = .02 and P < .01, respectively) multivariable models. Intraventricular hemorrhage at the time of index surgery was an additional predictor in the all-index model (P = .01)., Conclusion: This study demonstrates that only 3 variables are predictive of 30-day shunt failure when following established variable selection procedures, 2 of which are potentially under direct control of the surgeon., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: The preventable shunt revision rate (PSRR) was recently introduced in pediatric hydrocephalus as a quality metric for shunt surgery. We evaluated the PSRR in an adult hydrocephalus population., Methods: All ventricular shunt operations (January 1, 2013 to March 31, 2018) performed at a university-based teaching hospital were included. For any index surgery (de novo or revision) resulting in reoperation within 90 days, the index surgery details were collected, and a consensus decision was reached regarding whether the failure had been potentially avoidable. Preventable failure was defined as failure due to infection, malposition, disconnection, migration, or kinking. The 90-day shunt failure rate and PSRR were calculated. Bivariate analyses were performed to evaluate the individual effects of each independent variable on preventable shunt failure., Results: A total of 318 shunt operations had been performed in 245 patients. Most patients were women (62%), with a median age of 48.2 years (interquartile range, 31.2-63.2 years). Most had had ventriculoperitoneal shunts placed (86.5%), and just more than one half were new shunts (51.6%). A total of 53 cases (16.7%) in 42 patients experienced shunt failure within 90 days of the index operation. Of these, 27 failures (8.5% of the total cases; 51% of the failures) were considered potentially preventable. The most common reasons were infection (37%; n = 10) and malposition of the proximal and distal catheters (both 25.9%; n = 7). Age was the only statistically significant difference between the 2 groups, with the patients experiencing preventable shunt failure older than those without preventable shunt failure (51.4 vs. 37.1 years; P = 0.017)., Conclusions: The 90-day PSRR can be applied to an adult population and serve as a quality metric., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Pediatric supratentorial ependymomas (SEs) have distinct molecular and behavioral differences from their infratentorial counterparts., Objective: To present our experience with pediatric SEs over a 24-yr period., Methods: Clinical, operative, and radiographic information was abstracted retrospectively. Our primary outcomes were progression-free survival (PFS) and overall survival (OS). Detection of C11orf95-RELA rearrangement was performed using interphase fluorescence in situ hybridization (iFISH)., Results: Seventy-three patients were identified (41 female, 32 male); median age was 6.7 yrs (range, 1 mo-18.8 yr); median follow-up was 8.3 yrs (range, 2.0-26.3). Fifty-eight (79.5%) of 73 patients underwent gross total resection (GTR); no patient with subtotal resection had greater than 1 cm3 of residual tumor; 42 patients (57.5%) experienced subsequent disease progression with 17 patients ultimately dying of their disease. Median PFS was 3.7 yrs. Molecular analysis was available for 51 patients (70%). On bivariate analysis, PFS and OS were not statistically affected by age, tumor grade, or extent of resection, although there was a clinically significant trend for the latter in favor of aggressive resection on PFS (P = .061). Children with RELA fusion had significantly higher PFS (P = .013) than those without, although there was no difference in OS when compared with those with no C11orf95-RELA fusion or C11orf95 gene rearrangement alone., Conclusion: In our series, GTR may be associated with better PFS, but did not impact OS. Surprisingly, RELA fusion was not found to be a negative prognostic factor, raising the possibility that the deleterious effects may be overcome by aggressive resection., (Copyright © 2018 by the Congress of Neurological Surgeons.)

Background: The Preventable Shunt Revision Rate (PSRR) was recently introduced as a novel quality metric., Objective: To evaluate the PSRR across multiple centers and determine associated variables., Methods: Nine participating centers in North America provided at least 2 years of consecutive shunt operations. Index surgery was defined as new shunt implantation, or revision of an existing shunt. For any index surgery that resulted in a reoperation within 90-days, index surgery information (demographic, clinical, and procedural) was collected and a decision made whether the failure was potentially preventable. The 90-day shunt failure rate and PSRR were calculated per institution and combined. Bivariate analyses were performed to evaluate individual effects of each independent variable on preventable shunt failure followed by a final multivariable model using a backward model selection approach., Results: A total of 5092 shunt operations were performed; 861 failed within 90 days of index operation, resulting in a 16.9% combined 90-day shunt failure rate and 17.6% median failure rate (range, 8.7%-26.9%). Of the failures, 307 were potentially preventable (overall and median 90-day PSRR, 35.7% and 33.9%, respectively; range, 16.1%-55.4%). The most common etiologies of avoidable failure were infection (n = 134, 44%) and proximal catheter malposition (n = 83, 27%). Independent predictors of preventable failure (P < .05) were lack of endoscopy (odds ratio [OR] = 2.26), recent shunt infection (OR = 3.65), shunt type (OR = 2.06) and center., Conclusion: PSRR is variable across institutions, but can be 50% or higher. While the PSRR may never reach zero, this study demonstrates that overall about a third of early failures are potentially preventable., (Copyright © 2018 by the Congress of Neurological Surgeons.)

Objective: To analyze the role of industry sponsorship of randomized controlled trials (RCTs) published exclusively in 3 major North American neurosurgical journals., Methods: Our primary objective was to determine whether an association exists between study conclusion(s) in favor of industry sponsored drugs, devices/implants, or surgical techniques and industry sponsorship. The secondary objective was to describe the quality/quantity of these neurosurgical RCTs., Results: A total of 110 RCTs were analyzed, the majority were published in the Journal of Neurosurgery (85%) and were international in origin (55%). The most common subspecialty was spine (n = 29) and drug study was the most common type (n = 49). Overall quality was good with median Jadad and Detsky scores of 4 (range, 1-5) and 18 (range, 8-21), respectively. There was a statistically significant difference in RCTs with industry funding (31/40, 78%) versus those without (9/70, 13%) that published a favorable conclusion of the new drug, device/implant, or surgical technique (odds ratio [OR], 23.35; P < .0001). Multiple binomial logistic regression analysis identified "number of authors" as mildly protective (OR, 0.79; 95% confidence interval, 0.69-0.91; P = .001) and "industry funding" strongly predictive (OR, 12.34; 95% confidence interval, 2.97-51.29; P = .001) of a positive trial., Conclusion: Industry funding was associated with a much greater chance of positive findings in RCTs published in neurosurgical journals. Further efforts are needed to define the relationship between the authors and financial sponsors of neurosurgical research and explore the reasons for this finding.

Background: Shunt infections remain a significant challenge in pediatric neurosurgery. Numerous surgical checklists have been introduced to reduce infection rates., Objective: To introduce an evidence-based shunt surgery checklist and its impact on our shunt infection rate., Methods: Between January 1, 2008 and December 31, 2015, pediatric patients who underwent shunt surgery at our institution were indexed in a prospectively maintained database. All definitive shunt procedures were included. Shunt infection was defined according to the Center for Disease Control and Prevention's National Hospital Safety Network surveillance definition for surgical site infection. Clinical and procedural variables were abstracted per procedure. Infection data were compared for the 4 year before and 4 year after protocol implementation. Compliance was calculated from retrospective review of our checklists., Results: Over the 8-year study period, 1813 procedures met inclusion criteria with a total of 37 shunt infections (2%). Prechecklist (2008-2011) infection rate was 3.03% (28/924) and decreased to 1.01% (9/889; P = .003) postchecklist (2012-2015), representing an absolute risk reduction of 2.02% and relative risk reduction of 66.6%. One shunt infection was prevented for every 50 times the checklist was used. Those patients who developed an infection after protocol implementation were younger (0.95 years vs 3.40 years (P = .027)), but there were no other clinical or procedural variables, including time to infection, that were significantly different between the cohorts. Average compliance rate among required checklist components was 97% (range 85%-100%)., Conclusion: Shunt surgery checklist implementation correlated with lower infection rates that persisted in the 4 years after implementation.

Object  Primary closure of posterior fossa dura can be challenging, and postoperative cerebrospinal fluid (CSF) leaks continue to represent a common complication of the retrosigmoid approach. We describe a simple technique to allow for primary closure of the dura following retrosigmoid approaches. The incidence of CSF leaks using this method is reported. Methods  A retrospective chart review was conducted on all cases of retrosigmoid craniotomies performed by the senior surgeon from February 2009 to February 2015. The primary outcome was development of postoperative CSF leak or pseudomeningocele. Length of stay, lesion type, and other surgical complications were also reported. Results  Eighty-six patients underwent a retrosigmoid craniotomy during the study period. The most common indications for retrosigmoid craniotomy were microvascular decompression (58%) and tumor resection (36%). No allo- or autografts to repair the dural defect were needed, and no lumbar drains were used. No patients developed CSF otorrhea, rhinorrhea, or incisional leak postoperatively. Conclusion  Primary dural closure is possible in retrosigmoid approaches without the use of allo- or autografts and may prevent postoperative CSF leaks when combined with other posterior fossa closure techniques. Careful attention to the handling of the dural flap is necessary to achieve this.

OBJECTIVE There has been an increasing interest in the quantitative analysis of publishing within the field of neurosurgery at the individual, group, and institutional levels. The authors present an updated analysis of accredited pediatric neurosurgery training programs. METHODS All 28 Accreditation Council for Pediatric Neurosurgery Fellowship programs were contacted for the names of pediatric neurosurgeons who were present each year from 2011 through 2015. Faculty names were queried in Scopus for publications and citations during this time period. The 5-year institutional Hirsch index [i h(5)-index] and revised 5-year institutional h-index [i r(5)-index] were calculated to rank programs. Each publication was reviewed to determine authorship value, tier of research, clinical versus basic science research, subject matter, and whether it was pediatrics-specific. A unique 3-tier article classification system was introduced to stratify clinical articles by quality and complexity, with tier 3 being the lowest tier of publication (e.g., case reports) and tier 1 being the highest (e.g., randomized controlled trials). RESULTS Among 2060 unique publications, 1378 (67%) were pediatrics-specific. The pediatrics-specific articles had a mean of 15.2 citations per publication (median 6), whereas the non-pediatrics-specific articles had a mean of 23.0 citations per publication (median 8; p < 0.0001). For the 46% of papers that had a pediatric neurosurgeon as first or last author, the mean number of citations per publication was 12.1 (median 5.0) compared with 22.5 (median 8.0) for those in which a pediatric neurosurgeon was a middle author (p < 0.0001). Seventy-nine percent of articles were clinical research and 21% were basic science or translational research; however, basic science and translational articles had a mean of 36.9 citations per publication (median 15) compared with 12.6 for clinical publications (median 5.0; p < 0.0001). Among clinical articles, tier 1 papers had a mean of 15.0 citations per publication (median 8.0), tier 2 papers had a mean of 18.7 (median 8.0), and tier 3 papers had a mean of 7.8 (median 3.0). Neuro-oncology papers received the highest number of citations per publication (mean 25.7). The most common journal was the Journal of Neurosurgery: Pediatrics (20%). MD/PhD faculty members had significantly more citations per publication than MD faculty members (mean 26.7 vs 14.0; p < 0.0001) and also a higher number of publications per author (mean 38.6 vs 20.8). The median i h(5)- and i r(5)-indices per program were 14 (range 5-48) and 10 (range 5.6-37.2), respectively. The mean i r(5)/i h(5)-index ratio was 0.8. The top 5 fellowship programs (in descending order) as ranked by the i h(5)-index corrected for number of faculty members were The Hospital for Sick Children, Toronto; Children's Hospital of Pittsburgh; University of California, San Francisco Benioff Children's Hospital; Seattle Children's Hospital; and St. Louis Children's Hospital. CONCLUSIONS About two-thirds of publications authored by pediatric neurosurgeons are pediatrics-specific, although non-pediatrics-specific articles averaged more citations. Most of the articles authored by pediatric neurosurgeons are clinical, with basic and translational articles averaging more citations. Neurosurgeons with PhD degrees averaged more total publications and more citations per publication. In all, this is the most advanced and informative analysis of publication productivity in pediatric neurosurgery to date.

Background: Pineoblastomas are rare, supratentorial, primitive neuroectodermal tumors., Objective: To document outcomes with multimodal therapy and evaluate the impact that the degree of surgical resection has on outcome., Methods: A departmental brain tumor database was queried to identify all patients with pathologically proven pineoblastoma who were treated from January 1997 to June 2015 at St. Jude Children's Research Hospital. For each patient, we recorded demographic, pathological, radiological, surgical, and clinical follow-up data. The effect of degree of surgical resection on survival outcomes was analyzed., Results: Forty-one patients (21 male, 20 female) treated for pineoblastoma were identified. The median age at diagnosis was 5.5 years (range 0.4-28.1) and the median follow-up was 34.5 months. Nineteen patients experienced tumor relapse with a median progression-free survival of 11.3 months, and 18 ultimately succumbed to their disease. Patients who died or experienced treatment failure were younger (median, 2.69 vs 6.5 years, P = .026) and more likely to have metastatic disease at diagnosis (12 [63.2%] vs 5 [22.7%], P = .012). When analyzing only patients 5 years of age or older with focal disease at presentation, those who had a gross total resection or near-total resection-compared with subtotal resection or biopsy-had greater overall survival (75.18 vs 48.57 months), with no patients dying as a result of their cancer., Conclusion: Poor prognostic variables for children with pineoblastoma include young age, metastatic disease at presentation, and tumor relapse. For patients older than 5 years with focal disease, maximal tumor resection should be the goal., (Copyright © 2017 by the Congress of Neurological Surgeons)

Objective  This case series investigates management of glomus jugulare (GJ) tumors utilizing definitive and salvage Gamma Knife stereotactic radiosurgery (GKSRS). Methods  A retrospective chart review was performed to collect data. Statistical analysis included patient, tumor, and treatment information. Results  From 1996 to 2013, 17 patients with GJ received GKSRS. Median age was 64 years (range, 27-76). GKSRS was delivered for definitive treatment in eight (47%) and salvage in nine (53%) patients. Median tumor volume was 9.8 cm 3 (range, 2.8-42 cm 3 ). Median dose was 15 Gy (range, 13-18 Gy). Median follow-up was 123 months (range, 38-238 months). Tumor size decreased in 10 (59%), stabilized in 6 (35%), and increased in 1 patient (6%). Overall neurological deficit improved in 53%, stabilized in 41%, and worsened in 6% of patients. Overall cause-specific survival was 100%, and actuarial local control was 94%. Eighty-eight percent of patients without prior resection experienced neurologic deficit improvement, while 25% of patients with prior resection experienced neurologic improvement ( p  = 0.02). Conclusion  Gamma Knife radiosurgery provides effective long-term control of GJ and overall improvement or stabilization of neurological deficit in most patients. Patients with prior resection are less likely to experience improvement of neurologic deficit.

Background: Low-pressure hydrocephalus (LPH) is a rare phenomenon characterized by a clinical picture consistent with elevated intracranial pressure (ICP) and ventricular enlargement, but also a well-functioning shunt and low or negative ICP., Objective: To report our experience in evaluating this challenging problem., Methods: Patients with LPH were identified from several sources, including institutional procedural databases and personal case logs. Electronic medical records were reviewed to collect demographic, clinical, surgical, and radiographic data to determine the presence of LPH. Each patient's clinical course, including presentation, management, and outcome, is reported., Results: Thirty instances of LPH were identified in 29 patients. Eleven cases (37.9%) of LPH were after lumbar puncture (LP), and 19 cases (62.1%) occurred without any preceding spinal procedure. Among the post-LP patients, conservative measures alone were successful in 3 cases (27%); lumbar blood patch was successful in 2 cases (18%); and 6 cases (55%) required external cerebrospinal fluid (CSF) drainage. Of the spontaneous cases, 5 patients did not receive the full spectrum of treatment because of terminal prognosis. Of the remaining 14 patients, 11 (78.6%) required external CSF drainage. Post-LP patients required fewer days of external CSF drainage (median, 4 [range, 0-12] vs median, 11 [range, 0-90]) and had a shorter hospital stay (median, 2 [range, 2-16] vs median, 8 [range, 0-26])., Conclusion: This study represents the largest series of LPH. Although its pathophysiology remains a mystery, there are a variety of management options. Multiple procedures and a protracted hospital stay are often required to successfully treat LPH., (Copyright © 2016 by the Congress of Neurological Surgeons)

Background: We recently performed a comprehensive bibliometric analysis of 103 U.S. neurosurgical departments and found the ih(5)-index as meaningful and reproducible using public data. The present report expands this analysis by adding 14 Canadian and 2 additional U.S. programs., Methods: Departments were included if listed in the American Association of Neurological Surgeons Residency Directory. Each institution was considered a single entity, and original research articles with authors who were neurosurgeon faculty were counted only once per institution, although a single article may have been credited toward multiple institutions, if applicable. The following bibliometric indices were calculated and used to rank departments: ih(5), ig(5), ie(5), and i10(5). In addition, intradepartmental comparison of productivity among faculty members was analyzed by computing Gini coefficients for publications and citations., Results: The top 5 most academically productive North American neurosurgical programs based on ih(5)-index were found to be the University of Toronto, University of California at San Francisco, University of California at Los Angeles, University of Pittsburgh, and Brigham and Women's Hospital. The top 5 Canadian programs were the University of Toronto, University of Calgary, McGill University, University of Sherbrooke, and University of British Columbia. The median ih(5)-index for U.S. and Canadian programs was 12 and 10.5, respectively., Conclusions: This is the most accurate comprehensive analysis to date of contemporary bibliometrics among North American neurosurgery departments. Using the ih(5)-index for institutional ranking allows for informative comparison of recent scholarly efforts., (Copyright © 2016 Elsevier Inc. All rights reserved.)

OBJECTIVE Shunt surgery consumes a large amount of pediatric neurosurgical health care resources. Although many studies have sought to identify risk factors for shunt failure, there is no consensus within the literature on variables that are predictive or protective. In this era of "quality outcome measures," some authors have proposed various metrics to assess quality outcomes for shunt surgery. In this paper, the Preventable Shunt Revision Rate (PSRR) is proposed as a novel quality metric. METHODS An institutional shunt database was queried to identify all shunt surgeries performed from January 1, 2010, to December 31, 2014, at Le Bonheur Children's Hospital. Patients' records were reviewed for 90 days following each "index" shunt surgery to identify those patients who required a return to the operating room. Clinical, demographic, and radiological factors were reviewed for each index operation, and each failure was analyzed for potentially preventable causes. RESULTS During the study period, there were 927 de novo or revision shunt operations in 525 patients. A return to the operating room occurred 202 times within 90 days of shunt surgery in 927 index surgeries (21.8%). In 67 cases (33% of failures), the revision surgery was due to potentially preventable causes, defined as inaccurate proximal or distal catheter placement, infection, or inadequately secured or assembled shunt apparatus. Comparing cases in which failure was due to preventable causes and those in which it was due to nonpreventable causes showed that in cases in which failure was due to preventable causes, the patients were significantly younger (median 3.1 vs 6.7 years, p = 0.01) and the failure was more likely to occur within 30 days of the index surgery (80.6% vs 64.4% of cases, p = 0.02). The most common causes of preventable shunt failure were inaccurate proximal catheter placement (33 [49.3%] of 67 cases) and infection (28 [41.8%] of 67 cases). No variables were found to be predictive of preventable shunt failure with multivariate logistic regression. CONCLUSIONS With economic and governmental pressures to identify and implement "quality measures" for shunt surgery, pediatric neurosurgeons and hospital administrators must be careful to avoid linking all shunt revisions with "poor" or less-than-optimal quality care. To date, many of the purported risk factors for shunt failure and causes of shunt revision surgery are beyond the influence and control of the surgeon. We propose the PSRR as a specific, meaningful, measurable, and-hopefully-modifiable quality metric for shunt surgery in children.

Objective: Bradford's law describes the scatter of citations for a given subject or field. It can be used to identify the most highly cited journals for a field or subject. The objective of this study was to use currently accepted formulations of Bradford's law to identify core journals of neurosurgery and neurosurgical subspecialties., Methods: All original research publications from 2009 to 2013 were analyzed for the top 25 North American academic neurosurgeons from each subspecialty. The top 25 were chosen from a ranked career h-index list identified from previous studies. Egghe's formulation and the verbal formulation of Bradford's law were applied to create specific citation density zones and identify the core journals for each subspecialty. The databases were then combined to identify the core journals for all of academic neurosurgery., Results: Using Bradford's verbal law with 4 zone models, the authors were able to identify the core journals of neurosurgery and its subspecialties. The journals found in the most highly cited first zone are presented here as the core journals. For neurosurgery as a whole, the core included the following journals: Journal of Neurosurgery, Neurosurgery, Spine, Stroke, Neurology, American Journal of Neuroradiology, International Journal of Radiation Oncology Biology Physics, and New England Journal of Medicine. The core journals for each subspecialty are presented in the manuscript., Conclusions: Bradford's law can be used to identify the core journals of neurosurgery and its subspecialties. The core journals vary for each neurosurgical subspecialty, but Journal of Neurosurgery and Neurosurgery are among the core journals for each neurosurgical subspecialty.

Background: Minimally invasive transforaminal lumbar interbody fusion (TLIF)-or MI-TLIF-has been increasing in prevalence compared with open TLIF (O-TLIF) procedures. The use of MI-TLIF is an evolving technique with conflicting reports in the literature about outcomes., Objective: To investigate the impact of MI-TLIF in comparison with O-TLIF for early and late outcomes by using the Visual Analog Scale for back pain (VAS-back) and the Oswestry Disability Index (ODI). Secondary end points include blood loss, operative time, radiation exposure, length of stay, fusion rates, and complications between the 2 procedures., Methods: During August 2014, a systematic literature search was performed identifying 987 articles. Of these, 30 met inclusion criteria. A random-effects meta-analysis was performed by using both pooled and subset analyses based on study type., Results: Our meta-analysis demonstrated that MI-TLIF reduced blood loss (P < .001), length of stay (P < .001), and complications (P = .001) but increased radiation exposure (P < .001). No differences were found in fusion rate (P = .61) and operative time (P = .34). A decrease in late VAS-back scores was demonstrated for MI TLIF (P < .001), but no differences were found in early VAS-back, early ODI, and late ODI., Conclusion: MI-TLIF is associated with reduced blood loss, decreased length of stay, decreased complication rates, and increased radiation exposure. The rates of fusion and operative time are similar between MI-TLIF and O-TLIF. Differences in long-term outcomes in MI-TLIF vs O-TLIF are inconclusive and require more research, particularly in the form of large, multi-institutional prospective randomized controlled trials., Abbreviations: CI, confidence intervalMCID, minimal clinically important differenceMI-TLIF, minimally invasive transforaminal lumbar interbody fusionODI, Oswestry Disability IndexO-TLIF, open transforaminal lumbar interbody fusionVAS, Visual Analog Scale.

Object: Surgery for CSF diversion is the most common procedure performed by pediatric neurosurgeons. The failure rates for shunts remain frustratingly high, resulting in a burden to patients, families, providers, and healthcare systems. The goal of this study was to quantify the risk of a shunt malfunction in patients with an existing shunt who undergo an elective intradural operation., Methods: All elective intradural surgeries (cranial and spinal) at Le Bonheur Children's Hospital from January 2010 through June 2014 were reviewed to identify those patients who had a functional ventricular shunt at the time of surgery. Patient records were reviewed to collect demographic, surgical, clinical, radiological, and pathologic data, including all details related to any subsequent shunt revision surgery. The primary outcome was all-cause shunt revision (i.e., malfunction or infection) within 90 days of elective intradural surgery., Results: One hundred and fifty elective intradural surgeries were identified in 109 patients during the study period. There were 14 patients (12.8%, 13 male) who experienced 16 shunt malfunctions (10.7%) within 90 days of elective intradural surgery. These 14 patients underwent 13 craniotomies, 2 endoscopic fenestrations for loculated hydrocephalus, and 1 laminectomy for dorsal rhizotomy. Median time to failure was 9 days, with the shunts in half of our patients failing within 5 postoperative days. Those patients with failed shunts were younger (median 4.2 years [range 0.33-26 years] vs median 10 years [range 0.58-34 years]), had a shorter time interval from their previous shunt surgery (median 11 months [range 0-81 months] vs median 20 months [range 0-238 months]), and were more likely to have had intraventricular surgery (80.0% vs. 60.3%)., Conclusions: This is the first study to quantify the risk of a shunt malfunction after elective intradural surgery. The 90-day all-cause shunt failure rate (per procedure) was 10.7%, with half of the failures occurring within the first 5 postoperative days. Possible risk factors for shunt malfunction after elective intradural surgeries are intraventricular surgical approach, shorter time since last shunt-related surgery, and young age.

Object: Various bibliometric indices based on the citations accumulated by scholarly articles, including the h-index, g-index, e-index, and Google's i10-index, may be used to evaluate academic productivity in neurological surgery. The present article provides a comprehensive assessment of recent academic publishing output from 103 US neurosurgical residency programs and investigates intradepartmental publishing equality among faculty members., Methods: Each institution was considered a single entity, with the 5-year academic yield of every neurosurgical faculty member compiled to compute the following indices: ih(5), cumulative h, ig(5), ie(5), and i10(5) (based on publications and citations from 2009 through 2013). Intradepartmental comparison of productivity among faculty members yielded Gini coefficients for publications and citations. National and regional comparisons, institutional rankings, and intradepartmental publishing equality measures are presented., Results: The median numbers of departmental faculty, total publications and citations, ih(5), summed h, ig(5), ie(5), i10(5), and Gini coefficients for publications and citations were 13, 82, 716, 12, 144, 23, 16, 17, 0.57, and 0.71, respectively. The top 5 most academically productive neurosurgical programs based on ih(5)-index were University of California, San Francisco, University of California, Los Angeles, University of Pittsburgh, Brigham & Women's Hospital, and Johns Hopkins University. The Western US region was most academically productive and displayed greater intradepartmental publishing equality (median ih[5]-index = 18, median Ginipub = 0.56). In all regions, large departments with relative intradepartmental publishing equality tend to be the most academically productive. Multivariable logistic regression analysis identified the ih(5)-index as the only independent predictor of intradepartmental publishing equality (Ginipub ≤ 0.5 [OR 1.20, 95% CI 1.20-1.40, p = 0.03])., Conclusions: The ih(5)-index is a novel, simple, and intuitive metric capable of accurately comparing the recent scholarly efforts of neurosurgical programs and accurately predicting intradepartmental publication equality. The ih(5)-index is relatively insensitive to factors such as isolated highly productive and/or no longer academically active senior faculty, which tend to distort other bibliometric indices and mask the accurate identification of currently productive academic environments. Institutional ranking by ih(5)-index may provide information of use to faculty and trainee applicants, research funding institutions, program leaders, and other stakeholders.

Object: In this paper the authors present their experience treating children with recurrent craniopharyngioma who were initially managed with surgery followed by conformal radiation therapy (CRT)., Methods: A departmental oncology information system was queried to identify all children (< 18 years old) who received CRT for a craniopharyngioma between 1998 and 2010 (inclusive) and specifically those who experienced tumor progression. For each patient, the authors recorded the type of recurrence (solid, cystic, or both), the time interval to first progression and each subsequent progression, the associated treatment complications, and disease status at last follow-up evaluation., Results: Among the 97 patients that met criteria for entry into this study, 18 (18.6%) experienced tumor progression (9 cystic, 3 solid, 6 cystic and solid). The median time to first recurrence was 4.62 years (range 1.81-9.11 years). The subgroup included 6 female and 12 male patients with a median age of 7.54 years (range 3.61-13.83 years). Ten patients experienced first progression within 5 years of CRT. The 5- and 10-year treatment-free survival rates for the entire cohort were 89.0% (95% confidence interval [CI] 80.5%-93.9%) and 76.2% (95% CI 64%-85%), respectively. Seven patients had a single episode of progression and 11 had more than 1. The time interval between each subsequent progression was progressively shorter. The 18 patients underwent 38 procedures. The median follow-up duration for this group was 9.32 years (range 4.04-19.0 years). Three patients died, including 1 from perioperative complications., Conclusions: Craniopharyngioma progression after prior irradiation is exceedingly difficult to treat and local control is challenging despite repeated surgical procedures. Given our results, gross-total resection may need to be the surgical goal at the time of first recurrence, if possible. Decompressing new cyst formation alone has a low rate of long-term success.

Introduction: There are limited data evaluating intensive systolic blood pressure (SBP) control during the hyperacute phase of intracerebral hemorrhage (ICH) in patients with multiple risk factors for resistant hypertension. We evaluated the feasibility and safety of this intervention in a primary population that includes patients with multiple risk factors for resistant hypertension., Materials and Methods: We conducted a retrospective analysis of ICH patients for which intensive SBP control (<140 mm Hg)- i.e. less than or equal to 140 was targeted. All patients possessed at least 2 risk factors that have been associated with resistant hypertension. Our primary objective was to determine the percentage of patients who achieved goal SBP within 1 hour of ICH diagnosis. Secondary objectives included identifying predictors of achieving goal SBP within 6 hours., Results: Goal SBP within 1 hour was achieved in 8.1% of patients. The total number of risk factors a patient possessed was found to negatively predict ability to achieve goal SBP. For each risk factor possessed, the odds of achieving goal SBP within 6 hours are reduced by 31% (odds ratio, 0.69 [95% confidence interval, 0.54-0.89])., Conclusion: Intensive SBP control after ICH was difficult to achieve within 1 hour in those with risk factors for resistant hypertension. Patients' total risk factors were found to reduce the odds of achieving goal SBP within 6 hours., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Object: The application of bibliometric techniques to academic neurosurgery has been the focus of several recent publications. The authors provide here a detailed analysis of all active pediatric neurosurgeons in North America and their respective departments., Methods: Using Scopus and Google Scholar, a bibliometric profile for every known active pediatric neurosurgeon in North America was created using the following citation metrics: h-, contemporary h-, g-, and e-indices and the m-quotient. Various subgroups were compared. Departmental productivity from 2008 through 2013 was measured, and departments were ranked on the basis of cumulative h- and e-indices and the total number of publications and citations. Lorenz curves were created, and Gini coefficients were calculated for all departments with 4 or more members., Results: Three hundred twelve pediatric neurosurgeons (260 male, 52 female) were included for analysis. For the entire group, the median h-index, m-quotient, contemporary h-, g-, and e-indices, and the corrected g- and e-indices were 10, 0.59, 7, 18, 17, 1.14, and 1.01, respectively; the range for each index varied widely. Academic pediatric neurosurgeons associated with fellowship programs (compared with unassociated neurosurgeons), academic practitioners (compared with private practitioners), and men (compared with women) had superior measurements. There was no significant difference between American and Canadian pediatric neurosurgeons. The mean Gini coefficient for publications was 0.45 (range 0.18-0.70) and for citations was 0.53 (range 0.25-0.80)., Conclusions: This study represents the most exhaustive evaluation of academic productivity for pediatric neurosurgeons in North America to date. These results should serve as benchmarks for future studies.

Purpose: Bradford's law describes the number of core journals in a given field or subject and has recently been applied to neurosurgery. The objective of this study was to use currently accepted formulations of Bradford's law to identify core journals of pediatric neurosurgery. An additional analysis was completed to compare regional dependence on citation density among North American and European neurosurgeons., Methods: All original research publications from 2009 to 2013 were analyzed for the 25 top publishing pediatric neurosurgeons in North America and Europe, which were sampled to construct regional citation databases of all journal references. Regional differences were compared with each database. Egghe's formulation and the verbal formulation of Bradford's law were applied to create specific citation density zones and identify the core journals., Results: Regional comparison demonstrated a preference for the Journal of Neurosurgery and Child's Nervous System, respectively, but four of the top five journals were common to both groups. Applying the verbal formulation of Bradford's law to the North American citation database, a pattern of citation density was identified across the first three zones. Journals residing in the most highly cited first zone are presented as the core journals., Conclusion: Bradford's law can be applied to identify the core journals of neurosurgical subspecialties. While regional differences exist between the most highly cited and most frequently published in journals among North American and European pediatric neurosurgeons, there is commonality between the top five core journals in both groups.

Convection-enhanced delivery (CED) has been proposed as a treatment option for a wide range of neurological diseases. Neuroinfusion catheter CED allows for positive pressure bulk flow to deliver greater quantities of therapeutics to an intracranial target than traditional drug delivery methods. The clinical utility of real time MRI guided CED (rCED) lies in the ability to accurately target, monitor therapy, and identify complications. With training, rCED is efficient and complications may be minimized. The agarose gel model of the brain provides an accessible tool for CED testing, research, and training. Simulated brain rCED allows practice of the mock surgery while also providing visual feedback of the infusion. Analysis of infusion allows for calculation of the distribution fraction (Vd/Vi) allowing the trainee to verify the similarity of the model as compared to human brain tissue. This article describes our agarose gel brain phantom and outlines important metrics during a CED infusion and analysis protocols while addressing common pitfalls faced during CED infusion for the treatment of neurological disease.

Objective: The relationship between metrics, such as the h-index, and the ability of researchers to generate funding has not been previously investigated in neurosurgery. This study was performed to determine whether a correlation exists between bibliometrics and National Institutes of Health (NIH) funding data among academic neurosurgeons., Methods: The h-index, m-quotient, g-index, and contemporary h-index were determined for 1225 academic neurosurgeons from 99 (of 101) departments. Two databases were used to create the citation profiles, Google Scholar and Scopus. The NIH Research Portfolio Online Reporting Tools Expenditures and Reports tool was accessed to obtain career grant funding amount, grant number, year of first grant award, and calendar year of grant funding., Results: Of the 1225 academic neurosurgeons, 182 (15%) had at least 1 grant with a fully reported NIH award profile. Bibliometric indices were all significantly higher for those with NIH funding compared to those without NIH funding (P < .001). The contemporary h-index was found to be significantly predictive of NIH funding (P < .001). All bibliometric indices were significantly associated with the total number of grants, total award amount, year of first grant, and duration of grants in calendar years (bivariate correlation, P < .001) except for the association of m-quotient with year of first grant (P = .184)., Conclusions: Bibliometric indices are higher for those with NIH funding compared to those without, but only the contemporary h-index was shown to be predictive of NIH funding. Among neurosurgeons with NIH funding, higher bibliometric scores were associated with greater total amount of funding, number of grants, duration of grants, and earlier acquisition of their first grant., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Object: Bibliometrics is defined as the study of statistical and mathematical methods used to quantitatively analyze scientific literature. The application of bibliometrics in neurosurgery is in its infancy. The authors calculate a number of publication productivity measures for almost all academic neurosurgeons and departments within the US., Methods: The h-index, g-index, m-quotient, and contemporary h-index (hc-index) were calculated for 1225 academic neurosurgeons in 99 (of 101) programs listed by the Accreditation Council for Graduate Medical Education in January 2013. Three currently available citation databases were used: Google Scholar, Scopus, and Web of Science. Bibliometric profiles were created for each surgeon. Comparisons based on academic rank (that is, chairperson, professor, associate, assistant, and instructor), sex, and subspecialties were performed. Departments were ranked based on the summation of individual faculty h-indices. Calculations were carried out from January to February 2013., Results: The median h-index, g-index, hc-index, and m-quotient were 11, 20, 8, and 0.62, respectively. All indices demonstrated a positive relationship with increasing academic rank (p < 0.001). The median h-index was 11 for males (n = 1144) and 8 for females (n = 81). The h-index, g-index and hc-index significantly varied by sex (p < 0.001). However, when corrected for academic rank, this difference was no longer significant. There was no difference in the m-quotient by sex. Neurosurgeons with subspecialties in functional/epilepsy, peripheral nerve, radiosurgery, neuro-oncology/skull base, and vascular have the highest median h-indices; general, pediatric, and spine neurosurgeons have the lowest median h-indices. By summing the manually calculated Scopus h-indices of all individuals within a department, the top 5 programs for publication productivity are University of California, San Francisco; Barrow Neurological Institute; Johns Hopkins University; University of Pittsburgh; and University of California, Los Angeles., Conclusions: This study represents the most detailed publication analysis of academic neurosurgeons and their programs to date. The results for the metrics presented should be viewed as benchmarks for comparison purposes. It is our hope that organized neurosurgery will adopt and continue to refine bibliometric profiling of individuals and departments.