A Comparative Scientometric Analysis of the 100 Most Cited Articles of Acta Neurochirurgica (Wien) and World Neurosurgery.

BACKGROUND: Acta Neurochirurgica (ANCH) and World Neurosurgery (WN), are 2 journals of significant importance in the neurosurgical community and have been associated with international federations. These journals carry a similar impact factor. The difference is the years they have been active (ANCH starting publication in 1973 and WN in 2010). This factor allows for a unique opportunity to delve deep into comparative, scientometric parameters, to understand the evolution of neurosurgical research. METHODS: A title-specific search of the Web of Science database using the keywords "Acta Neurochirurgica," "Acta," "Neurochirurgica," "World Neurosurgery," "World," and "Neurosurgery" was performed and arranged according to number of citations. The title of the articles, authors, corresponding authors, country of origin, journal of publication, year of publication, citation count. and journal impact factor were assessed. RESULTS: The average citation for ANCH was 170.1 citations, most being original articles (83/100). The articles of WN garnered nearly 70.48 citations, averaging 8.3 citations per publication. Most corresponding authors in ANCH originated from Germany with neuro-oncology, followed by neurotrauma and vascular as subjects. In contrast, the United States followed by China were the most common countries of origin for WN, with endoscopy and skull base being the topics achieving high impact. CONCLUSIONS: Neurotrauma and consensus guidelines have been shown to have maximal citations for ANCH whereas endoscopy and skull base lesions garnered the most for WN. Author subspecialization and increased collaboration across specialties with more articles on refinement of technique and outcome have emerged as recent trends.

Factors Associated with Subsequent Subarachnoid Hemorrhages in Patients with Multiple Intracranial Aneurysms.

BACKGROUND: Detection of multiple intracranial aneurysms (MIAs) in patients with aneurysmal subarachnoid hemorrhage (aSAH) is common and the optimal management of the additional unruptured intracranial aneurysms (UIA) is often a matter of debate. We calculate the incidence and the factors associated with subsequent aSAHs from untreated additional aneurysms in a single-center group of patients with aSAH and MIAs. METHODS: Charts of patients with MIAs admitted to our neurosurgery department for aSAH between January 2000 and March 2020 were retrospectively reviewed. Incidence rate and factors associated with subsequent aSAHs were calculated with univariable and multivariable analyses. RESULTS: Of the unruptured aneurysms, 50% were preventively treated. During a median follow-up of 3 years, 20 of 174 patients (11.5%) presented with a second aSAH. Incidence of rupture of an additional untreated aneurysm was 18.05 per 1000 person/years (confidence interval, 10.69-30.47). Rupture incidence of an additional aneurysm located in the anterior circulation was 32.70 per 1000 person/years and 40.73 per 1000 person/years in the posterior circulation. Presence of untreated mirror and de novo aneurysms increased the risk of overall subsequent aSAHs by 16.9-fold and 7.6-fold, respectively. Most untreated additional aneurysms causing a subsequent aSAH were smaller than 7 mm (73.3%), with middle cerebral artery being the most frequent location (40.0%). CONCLUSIONS: Incidence of subsequent aSAHs is high in patients with aSAH-MIA. Untreated mirror and de novo aneurysms are associated with higher rupture risk. Longer follow-up and prophylactic treatment of asymptomatic aneurysms at higher rupture risk are recommended to prevent the significant poor outcome of subsequent aSAHs.

Prediction Models in Aneurysmal Subarachnoid Hemorrhage: Forecasting Clinical Outcome With Artificial Intelligence.

BACKGROUND: Predicting outcome after aneurysmal subarachnoid hemorrhage (aSAH) is known to be challenging and complex. Machine learning approaches, of which feedforward artificial neural networks (ffANNs) are the most widely used, could contribute to the patient-specific outcome prediction. OBJECTIVE: To investigate the prediction capacity of an ffANN for the patient-specific clinical outcome and the occurrence of delayed cerebral ischemia (DCI) and compare those results with the predictions of 2 internationally used scoring systems. METHODS: A prospective database was used to predict (1) death during hospitalization (ie, mortality) (n = 451), (2) unfavorable modified Rankin Scale (mRS) at 6 mo (n = 413), and (3) the occurrence of DCI (n = 362). Additionally, the predictive capacities of the ffANN were compared to those of Subarachnoid Haemorrhage International Trialists (SAHIT) and VASOGRADE to predict clinical outcome and occurrence of DCI. RESULTS: The area under the curve (AUC) of the ffANN showed to be 88%, 85%, and 72% for predicting mortality, an unfavorable mRS, and the occurrence of DCI, respectively. Sensitivity/specificity rates of the ffANN for mortality, unfavorable mRS, and the occurrence of DCI were 82%/80%, 94%/80%, and 74%/68%. The ffANN and SAHIT calculator showed similar AUCs for predicting personalized outcome. The presented ffANN and VASOGRADE were found to perform equally with regard to personalized prediction of occurrence of DCI. CONCLUSION: The presented ffANN showed equal performance when compared with VASOGRADE and SAHIT scoring systems while using less individual cases. The web interface launched simultaneously with the publication of this manuscript allows for usage of the ffANN-based prediction tool for individual data (https://nutshell-tool.com/).

Avoiding predatory publishing for early career neurosurgeons: what should you know before you submit?

BACKGROUND: Scientific research can offer the joy of discovery. For many graduating neurosurgeons, often, a seminar, class, or instructional module is their first and only formal exposure to the world of conducting research responsibly, to write down and report the results of such research. The pressure to publish scientific research is high, but any young neurosurgeon who is unaware of how predatory publishers operate can get duped by it and can lose their valuable and hard-fought research. Hence, we have attempted to provide an overview of all potentially predatory neurosurgery publications and provide some "red flags" to recognize them. METHODS: A suspected list of predatory publications was collected via a thorough review of the Neurosurgery journals listed in 4 major so-called blacklists, i.e., Beall's list, Manca's list, Cabell's blacklist, and Strinzel blacklist and then cross-referenced with UGC CARE whitelist to remove any potential legitimate journals. All journals with a scope of the Neurosurgery publication were searched using terms in the search bar: "Neurosurgery", "Neuroanatomy", "Neuropathology", and "Neurological disorder/disease". Since all predatory journals claim to be open access, all possible types of open access journals on Scimago were also searched, and thus a comparison was possible in terms of publication cost and number of legitimate open access journals when compared with predatory ones. In addition, methodologies by which these journals penetrate legitimate indexes like PubMed was investigated. RESULTS: A total of 46 predatory journals were found and were enlisted along with their publishers and web addresses. Sixty of the 360 Neurosurgery journals listed on Scimago were open access and the fee for the predatory journals was substantially lower (< $150) when compared with legitimate journals ($900-$3000). Six types of open access types exist while a total of 26 red flags in 7 stages of publication can be found in predatory journals. These journals have penetrated indexes by having similar names to legitimate journals and by publishing articles with external funding which mandate their indexing. CONCLUSION: These 46 journals were defined as predatory by 4 major blacklists, and none of them was found in the UGC Care white list. They also fulfill the 26 red-flags that define a predatory journal. The blacklist detailed here may become redundant; hence "whenever in doubt" regarding a journal with "red-flags", the authors are advised to refer to whitelists to be on the safer side. Publishing in predatory journals leads to not only loss of valuable research but also discredits a researcher among his peers and can be hindrance in career progression. Some journals are even indexed on PubMed, and they have sophisticated webpages and high-quality online presentations.

Genetic analysis of spinal dysraphism with a hamartomatous growth (appendix) of the spinal cord: a case series.

BACKGROUND: Spinal dysraphism with a hamartomatous growth (appendix) of the spinal cord is better known as herniated spinal cord. There are many arguments in favour of considering it a developmental defect. From this point of view, it is a type of neural tube disorder. Neural tube disorders can be caused by multiple factors, including a genetic factor. A common genetic defect in patients with a spinal dysraphism with a hamartomatous growth of the spinal cord is sought for. CASE PRESENTATION: In two patients with a symptomatic lesion and referred to an academic hospital a genetic analysis was performed after informed consent. Whole-exome analysis was performed. : Whole-exome analysis did not result in identification of a clinically relevant genetic variant. CONCLUSIONS: This the first study to investigate the genetic contribution to spinal dysraphism with a hamartomatous growth (appendix) of the spinal cord. We could not establish a genetic cause for this entity. This conclusion cannot be definitive due to the small sample size. However, the incidental occurrence, the lack of reports of inheritance of this disorder and the absence of contribution to syndromal disorders favours a defect of normal development of the spinal cord.

Flow diversion treatment for acutely ruptured aneurysms.

BACKGROUND AND PURPOSE: Flow diverters are sometimes used in the setting of acutely ruptured aneurysms. However, thromboembolic and hemorrhagic complications are feared and evidence regarding safety is limited. Therefore, in this multicenter study we evaluated complications, clinical, and angiographic outcomes of patients treated with a flow diverter for acutely ruptured aneurysms. METHODS: We conducted a retrospective observational study of 44 consecutive patients who underwent flow diverter treatment within 15 days after rupture of an intracranial aneurysm at six centers. The primary end point was good clinical outcome, defined as modified Rankin Scale score (mRS) 0-2. Secondary endpoints were procedure-related complications and complete aneurysm occlusion at follow-up. RESULTS: At follow-up (median 3.4 months) 20 patients (45%) had a good clinical outcome. In 20 patients (45%), 25 procedure-related complications occurred. These resulted in permanent neurologic deficits in 12 patients (27%). In 5 patients (11%) aneurysm re-rupture occurred. Eight patients died resulting in an all-cause mortality rate of 18%. Procedure-related complications were associated with a poor clinical outcome (mRS 3-6; OR 5.1(95% CI 1.0 to 24.9), p=0.04). Large aneurysms were prone to re-rupture with rebleed rates of 60% (3/5) vs 5% (2/39) (p=0.01) for aneurysms with a size ≥20 mm and <20 mm, respectively. Follow-up angiography in 29 patients (median 9.7 months) showed complete aneurysm occlusion in 27 (93%). CONCLUSION: Flow diverter treatment of ruptured intracranial aneurysms was associated with high rates of procedure-related complications including aneurysm re-ruptures. Complications were associated with poor clinical outcome. In patients with available angiographic follow-up, a high occlusion rate was observed.

NeuroForm Atlas Stent-Assisted Coiling: Preliminary Results.

BACKGROUND: Stent-assisted coiling (SAC) is increasingly being performed as intervention for wide-neck intracranial aneurysms. The NeuroForm Atlas Stent (CE-marked; Stryker, Kalamazoo, Michigan) is relatively new. OBJECTIVE: To evaluate the effectiveness and safety of NeuroForm Atlas SAC for intracranial aneurysms in the first such study. METHODS: We retrospectively analyzed data from all patients treated with the NeuroForm Atlas SAC of an intracranial aneurysm, both ruptured and unruptured, between June 2015 and December 2016. Primary end-points were favorable clinical outcomes (modified Rankin scale score 0-2) and successful aneurysm occlusion (Raymond-Roy class I/II), both at 6-mo follow-up. Secondary end-points were the occurrence of intervention-related complications leading to permanent neurological deficit, the occurrence of intervention-related stroke and neurological death, immediate aneurysm occlusion, rupture (or rerupture) of the aneurysm, and recanalization. RESULTS: Twenty-seven consecutive patients, 10 with ruptured saccular wide-neck aneurysms, were treated with NeuroForm Atlas SAC. At 6-mo follow-up, 18/26 (69.2%) survivors had successful aneurysm occlusion and 22/26 (84.6%) had favorable clinical outcome. One patient had died of a cause unrelated to treatment. No intervention-related complications leading to permanent neurological deficit occurred. However, intraprocedural thromboembolic complications occurred in 4/27 patients (14.8%), and ischemic stroke related to treatment occurred in 4/26 (15.4%). No hemorrhagic complications were observed. CONCLUSION: NeuroForm Atlas SAC is a feasible way to treat ruptured and unruptured wide-neck aneurysms that are not amenable to conventional coiling or clipping. Aneurysm occlusion and favorable clinical outcome are consistent with previously reported rates for SAC of wide-neck aneurysms with other devices.

Pathogenesis of Idiopathic Ventral Herniation of Spinal Cord: Neuropathologic Analysis.

BACKGROUND: Idiopathic ventral herniation of the spinal cord is rarely seen as a cause of gradually increasing neurologic deficit. Its cause has never been clarified. It could be the result of a developmental disorder at 30- to 60-day gestational age. Neuropathologic analysis of herniated spinal cord tissue could probably support this hypothesis. CASE DESCRIPTION: In a patient suffering from idiopathic ventral herniation of the spinal cord, a biopsy was performed in order to reduce the space-occupying effect. The biopsy was taken while intraoperative neuromonitoring was used. The patient recovered uneventfully without any additional deficit. Tissue analysis included histopathologic, immunohistochemical, and molecular examination (methylation profiling). The tissue did not appear as a normally functioning spinal cord; instead, a non-neoplastic glio-(neuronal) proliferation was found. CONCLUSION: These findings support a developmental disorder as a cause for idiopathic ventral spinal cord herniation.

Toward Shorter Hospitalization After Endoscopic Transsphenoidal Pituitary Surgery: Day-by-Day Analysis of Early Postoperative Complications and Interventions.

BACKGROUND: It is unclear which patients have the greatest risk of developing complications in the first days after endoscopic transsphenoidal pituitary surgery (ETS) and how long patients should stay hospitalized after surgery. The objective of this study is to identify which patients are at risk for early postoperative medical and surgical reinterventions to optimize the length of hospitalization. METHODS: The medical records of 146 patients who underwent ETS for a pituitary adenoma between January 2013 and July 2016 were reviewed retrospectively. Data were collected on baseline patient-related characteristics, characteristics of the pituitary adenoma, perioperative complications and interventions, and postoperative outcomes. Patients who underwent additional interventions on days 2, 3, and 4 after ETS were identified as cases, and patients who did not have any interventions after day 1 postoperatively were identified as controls. RESULTS: Diabetes mellitus (odds ratio [OR], 4.279; 95% confidence interval [CI], 1.149-15.933; P = 0.03), incomplete adenoma resection (OR, 2.840; 95% CI, 1.228-6.568; P = 0.02) and increased morning sodium concentration on day 2 after surgery (OR, 5.211; 95% CI, 2.158-12.579; P <0.001) were associated with reinterventions. Patients without interventions on day 1 or 2 had only an 18.6% chance of a reintervention (OR, 0.201; 95% CI, 0.095-0.424). CONCLUSIONS: Patients with diabetes mellitus, incomplete adenoma resection, and increased morning sodium concentration on day 2 after surgery have an increased chance on reinterventions. In addition, patients without any interventions on day 1 and 2 are at low risk for later reinterventions. These patients could be suitable candidates for early hospital discharge.

The Pathogenesis of Ventral Idiopathic Herniation of the Spinal Cord: A Hypothesis Based on the Review of the Literature.

Idiopathic ventral herniation of the spinal cord (SC) is not often encountered in daily practice. Its clinical prevalence, however, will increase through increasing awareness and more frequent use of MRI. A clear explanation of its pathophysiology has never been formulated. It was hypothesized that the findings during surgery might indicate the real causative mechanism. An extensive literature search was performed, using Embase, PubMed, and Google Scholar. Titles and abstracts were screened by two investigators, using strict inclusion and exclusion criteria. Reference lists of the full paper versions of each included article were checked. The following data were registered for the articles included: age, gender, level of herniation, relation to intervertebral disk, duration of symptoms, findings from surgery, and outcomes. Nine cases treated at our department were added. A total of 117 articles reporting on 259 patients were included. Including our cases, 268 patients were reviewed. Females outnumbered males (160/100). The mean age was 51.3 ± 12.0 years. In 236 patients, the duration of symptoms was reported: 55.5 ± 55.6 months. In 178 patients, the intraoperative findings for the herniated part of the SC were not mentioned. In 59 patients, a tumor-like extrusion was seen, without any alteration to the SC. Deformation of the SC itself was never observed. Biopsies of these structures were without clinical consequence. Based on the intraoperative findings reported in literature and the cases presented, acquired causes, such as trauma and erosion of the dura due to a herniated disk, were not plausible. We hypothesize that a non-functioning appendix to the SC can only develop during an early embryologic phase, in which several layers separate. We propose renaming this entity as congenital transdural appendix of the SC.

A Meningoencephalocele Caused by a Chronic Growing Skull Fracture in a 76-Year-Old Patient.

We present a case of a growing skull fracture in adult male, with an interval of 43 years after initial trauma. This finding is extremely rare, especially because growing skull fractures are mostly seen as an uncommon complication of pediatric head trauma with calvarial fracture. In our patient, this finding was incidental, existed for many years, and had no clinical consequences. Therefore, we advised a conservative treatment for our patient.

Aneurysm diameter as a risk factor for pretreatment rebleeding: a meta-analysis.

OBJECT: Aneurysmal rerupture prior to treatment is a major cause of death and morbidity in aneurysmal subarachnoid hemorrhage. Recognizing risk factors for aneurysmal rebleeding is particularly relevant and might help to identify the aneurysms that benefit from acute treatment. It is uncertain if the size of the aneurysm is related to rebleeding. This meta-analysis was performed to evaluate whether an association could be determined between aneurysm diameter and the rebleeding rate before treatment. Potentially confounding factors such age, aneurysm location, and the presence of hypertension were also evaluated. METHODS: The authors systematically searched the PubMed, Embase, and Cochrane databases up to April 3, 2013, for studies of patients with aneurysmal subarachnoid hemorrhage that reported the association between aneurysm diameter and pretreatment aneurysmal rebleeding. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria were used to evaluate study quality. RESULTS: Seven studies, representing 2121 patients, were included in the quantitative analysis. The quality of the studies was low in 2 and very low in 5. Almost all of the studies used 10 mm as the cutoff point for size among other classes, and only one used 7 mm. An analysis was performed with this best unifiable cutoff point. Overall rebleeding occurred in 360 (17.0%) of 2121 patients (incidence range, from study to study, 8.7%-28.4%). The rate of rebleeding in small and large aneurysms was 14.0% and 23.6%, respectively. The meta-analysis of the 7 studies revealed that larger size aneurysms were at a higher risk for rebleeding (OR 2.56 [95% CI 1.62-4.06]; p = 0.00; I (2) = 60%). The sensitivity analysis did not alter the results. Five of the 7 studies reported data regarding age; 4 studies provided age-adjusted results and identified a persistent relationship between lesion size and the risk of rebleeding. The presence of hypertension was reported in two studies and was more prevalent in patients with rebleeding in one of these. Location (anterior vs posterior circulation) was reported in 5 studies, while in 4 there was no difference in the rebleeding rate. One study identified a lower risk of rebleeding associated with posterior location aneurysms. CONCLUSIONS: This meta-analysis showed that aneurysm size is an important risk factor for aneurysmal rebleeding and should be used in the clinical risk assessment of individual patients. The authors' results confirmed the current guidelines and underscored the importance of acute treatment for large ruptured aneurysms.

An online health community for aneurysmal subarachnoid hemorrhage patients: a pilot study.

BACKGROUND: Aneurysmal subarachnoid hemorrhage (aSAH) is a condition affecting relatively young patients and has high rates of morbidity and mortality. Online health communities have emerged to fill the void for patient advocacy and information, allowing individuals with shared experiences and chronic disorders to connect. OBJECTIVE: We have developed an online health community for aSAH patients, and this pilot study was conducted to evaluate it from a patient's perspective. METHODS: We implemented an online, members-only, health community (MijnSAB, translation: MySAH) in addition to the usual aSAH care at Radboudumc, Nijmegen, the Netherlands. A questionnaire that was sent to consecutive aSAH patients was used to evaluate the usability and utility of MySAH. Answers were provided using a 5-point Likert scale. There was also one open-ended question asking about what was missing from the MySAH tool. RESULTS: In total, 66 consecutive patients with aneurysmal subarachnoid hemorrhage were informed about the online health community. Of 64 potential MySAH users, 26 patients gained access to MySAH, 20 of whom were willing to participate in the evaluation. Those who used the community were younger (P=.03) and in a better condition at discharge (P=.03). The patients were positive about MySAH's contribution to the quality of their care, but not to their quality of life. Most patients (18/20, 90%) reported that they would recommend the community to others in their position. Open suggestions on how to improve the tool included more frequent blogs, including by a rehabilitation specialist. CONCLUSIONS: This pilot study showed that the online health community, MySAH, has a beneficial effect on the aftercare of patients suffering from aSAH because it gives easy access to relevant information provided by peers or caregivers. Due to the variable clinical outcomes after aSAH, the tool will mainly be useful for a select group of patients (with a better clinical outcome).

Treatment outcome in carpal tunnel syndrome: does distribution of sensory symptoms matter?

BACKGROUND: Patients with complaints of carpal tunnel syndrome (CTS) with signs and symptoms not exclusively confined to the median nerve territory, but otherwise fulfilling the clinical criteria may erroneously be withheld from therapy. METHODS: One hundred and twenty one patients who fulfilled the clinical criteria for the diagnosis of CTS with signs and symptoms restricted to the median nerve territory (group A) and 91 patients without this restriction (group B) were included in a prospective cohort study. All patients fulfilled electrodiagnostic criteria of CTS. Outcome was determined after 7 to 9 months by means of Symptom Severity Score (SSS) and Functional Status Score (FSS) according to Levine and a patient satisfaction questionnaire. RESULTS: Response rates were 81.8% (group A) and 82.4% (group B). All patients in group B had sensory symptoms involving digit 5. There were no significant differences in improvement of SSS, FSS and patient satisfaction scores between groups after treatment. CONCLUSION: CTS patients with characteristic sensory signs and symptoms not exclusively restricted to the median nerve innervated area should be treated in the same manner as patients with CTS symptoms restricted to the median nerve innervated area and should therefore not be withheld from surgical treatment.

The value of the Charlson Co-morbidity Index in aneurysmal subarachnoid haemorrhage.

BACKGROUND: Several studies have included different co-morbid conditions in prediction models for stroke patients. For subarachnoid haemorrhage (SAH), it is not known whether the Charlson Co-morbidity Index (CCI) is associated with outcome. We evaluated if this index was associated with outcome in patients with ruptured intracerebral aneurysms. METHODS: The data of all consecutive aneurysmal SAH (aSAH) patients treated at the Radboudumc, Nijmegen, The Netherlands and entered in the database were retrospectively analysed. Clinical condition at admission was recorded using the WFNS (World Federation of Neurological Surgeons Grading System) grade was collected, as were the age and treatment modality. The burden of co-morbidity was retrospectively registered using the CCI. Outcome was dichotomised on the modified Rankin Scale (mRS; 0-2, favourable outcome; 3-6, unfavourable outcome). A binary logistic regression analysis was performed. RESULTS: Between 6th May 2008 and 31st July 2013, 457 patients were admitted because of non-traumatic SAH (aSAH). Seventy-seven (16.8 %) patients had no aneurysm. Of the 380 patients with aSAH, information on co-morbid conditions was available for 371 patients. Thirty-six of those 371 had no treatment because of: bad clinical condition in 34 (9.2 %), a non-treatable dissecting aneurysm in 1 (0.3 %) and the explicit wishes of another. Co-morbidity was present in 113 (31.5 %) patients. Binary logistic regression analysis revealed no added value of using the CCI in predicting the outcome (p = 0.91). CONCLUSIONS: This study reports that the CCI is not associated with the outcome classified on the mRS at 6 months in patients after aSAH. The CCI has no added value in case-mix correction.

Caseload as a factor for outcome in aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis.

OBJECT: Increasing evidence exists that treatment of complex medical conditions in high-volume centers is found to improve outcome. Patients with subarachnoid hemorrhage (SAH), a complex disease, probably also benefit from treatment at a high-volume center. The authors aimed to determine, based on published literature, whether a higher hospital caseload is associated with improved outcomes of patients undergoing treatment after aneurysmal subarachnoid hemorrhage. METHODS: The authors identified studies from MEDLINE, Embase, and the Cochrane Library up to September 28, 2012, that evaluated outcome in high-volume versus low-volume centers in patients with SAH who were treated by either clipping or endovascular coiling. No language restrictions were set. The compared outcome measure was in-hospital mortality. Mortality in studies was pooled in a random effects meta-analysis. Study quality was reported according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) criteria. RESULTS: Four articles were included in this analysis, representing 36,600 patients. The quality of studies was graded low in 3 and very low in 1. Meta-analysis using a random effects model showed a decrease in hospital mortality (OR 0.77 [95% CI 0.60-0.97]; p = 0.00; I(2) = 91%) in high-volume hospitals treating SAH patients. Sensitivity analysis revealed the relative weight of the 1 low-quality study. Removal of the study with very low quality increased the effect size of the meta-analysis to an OR of 0.68 (95% CI 0.56-0.84; p = 0.00; I(2) = 86%). The definition of hospital volume differed among studies. Cutoffs and dichotomizations were used as well as division in quartiles. In 1 study, low volume was defined as 9 or fewer patients yearly, whereas in another it was defined as fewer than 30 patients yearly. Similarly, 1 study defined high volume as more than 20 patients annually, and another defined it as more than 50 patients a year. For comparability between studies, recalculation was done with dichotomized data if available. Cross et al., 2003 (low volume ≤ 18, high volume ≥ 19) and Johnston, 2000 (low volume ≤ 31, high volume ≥ 32) provided core data for recalculation. The overall results of this analysis revealed an OR of 0.85 (95% CI 0.72-0.99; p = 0.00; I(2) = 87%). CONCLUSIONS: Despite the shortcomings of this study, the mortality rate was lower in hospitals with a larger caseload. Limitations of the meta-analysis are the not uniform cutoff values and uncertainty about case mix.

3'-Deoxy-3'-18F-fluorothymidine PET-derived proliferative volume predicts overall survival in high-grade glioma patients.

UNLABELLED: 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) is a radiopharmaceutical depicting tumor cell proliferation with PET. In malignancies of the lung, breast, head and neck, digestive tract, brain, and other organs, quantitative assessment of (18)F-FLT targeting has been shown to correlate with the proliferation marker Ki-67 and with clinical outcome measures such as time to progression and overall survival (OS). The aim of this study was to assess various PET segmentation methods to estimate the proliferative volume (PV) and their prognostic value for OS in patients with suspected high-grade glioma. METHODS: Twenty-six consecutive patients underwent preoperative (18)F-FLT PET/CT and T1-weighted MRI of the brain after contrast application. The maximum standardized uptake value (SUV(max)) of all tumors was calculated, and 3 different segmentation methods for estimating the PV were used: the 50% isocontour of the SUV(max) signal for the PV(50%), the signal-to-background ratio (SBR) for an adaptive threshold delineation (PV(SBR)) method, and the iterative background-subtracted relative threshold level (RTL) method to estimate the PV(RTL). The prognostic value of the SUV(max) and the different PVs for OS were assessed. RESULTS: Twenty-two patients had glioblastoma multiforme, 2 had anaplastic oligodendroglioma, 1 had anaplastic ependymoma, and 1 had anaplastic astrocytoma. The median OS was 397 d (95% confidence interval, 204-577); 19 patients died during the follow-up period. The PV(SBR) showed a significantly (P = 0.002) better association with OS than did SUV(max), PV(RTL), and PV(50%). Receiver-operating-characteristic analysis resulted in a threshold volume for the PV(SBR) of 11.4 cm(3), with a sensitivity and specificity of 70% and 83%, respectively, for the prediction of OS. Kaplan-Meier analyses showed a significant discrimination between short and long OS (P = 0.024, log rank) for this threshold. CONCLUSION: The PV as determined by (18)F-FLT PET is associated with OS in high-grade malignant gliomas. The SBR method yielded the best results to predict short and long OS.

Primary hypertension and neurovascular compression: a meta-analysis of magnetic resonance imaging studies.

OBJECT: Several studies have suggested that neurovascular compression (NVC) of the brainstem might be a cause of hypertension. Because this compression syndrome might be demonstrated by MR imaging studies, several authors have tried to assess its prevalence in small series of patients with hypertension. This article presents a meta-analysis of these studies. METHODS: The studies reviewed by the authors were based on MR imaging and included the presence of left-sided NVC of the left rostral ventrolateral medulla oblongata (RVLM) and/or the cranial nerves IX and X root entry zone in patients with apparent primary hypertension compared with normotensive patients. Several studies also included patients with secondary hypertension as an additional control group, which is analyzed separately. RESULTS: Meta-analysis included data from 14 studies (597 patients with primary hypertension and 609 controls). The effect size was OR 2.68 (95% CI 1.51-4.75, p = 0.001) (random effect), which is consistent with the hypothesis that NVC of the left RVLM is more frequent in patients with apparent primary hypertension compared with normotensive individuals. Stratification for the study design revealed an effect size for prospective studies of OR 1.97 (95% CI 0.74-5.30, p = 0.178) and for retrospective studies of OR 3.36 (95% CI 1.66-6.79, p = 0.001). CONCLUSIONS: This meta-analysis indicates a statistically significant effect size for left-sided NVC in apparent primary hypertension. However, this effect is absent if subanalysis is confined to prospective studies.