Michael Ivan | University of Miami (original) (raw)
Papers by Michael Ivan
Neuro-Oncology
BACKGROUND AND PURPOSE The goal of this study was to systematically review the existing literatur... more BACKGROUND AND PURPOSE The goal of this study was to systematically review the existing literature on neurosurgical management and outcomes of brain metastasis from pancreatic cáncer in comparison to our institutional experience of this patient cohort. METHODS Following the PRISMA guidelines, a systematic literature review was performed using PubMed, Ovid Embase, Scopus, and Web of Science databases from date of database inception to January 2022. Studies were selected based on predetermined inclusion and exclusión criteria. Simulteanously, a retrospective analysis was conducted on patients who underwent neurosurgical evaluation and treatment for intracranial metastatic lesions from pancreatic origin at a single institution. RESULTS Of the total 292 articles in the original literature search, 17 studies were ultimately selected. A total of 23 patients with brain metastases of pancreatic origin were included. Median overall survival from original diagnosis of pancreatic cancer was 22...
Neuro-Oncology
INTRODUCTION The concept of enhanced recovery after surgery (ERAS) due to standardized interventi... more INTRODUCTION The concept of enhanced recovery after surgery (ERAS) due to standardized interventions has been gaining more relevance within neurosurgery. Advances were made both in protocols for spine and cranial surgery. These experiences described many benefits such as less psychological stress, reduction in hospitalization days, and lower hospital costs, without increasing the incidence of complications. However, no experience has described to date the applicability of an ERAS program for laser ablation thermal therapy (LITT). OBJECTIVE To describe our initial experience with the first enhanced recovery program reported for laser ablation for brain tumors. Secondly, to summarize the perioperative clinical outcomes of ERAS applied to LITT. METHODS We performed a retrospective analysis of all adult patients who underwent LITT for oncological lesions from 2013 to 2021. A multidisciplinary program was created by protocolizing interventions carried out along the path of the patient...
Operative Neurosurgery, 2020
Figure S2. A longitudinal study on a single GBM patient was carried out in order to monitor the c... more Figure S2. A longitudinal study on a single GBM patient was carried out in order to monitor the changes in serum HOTAIR expression over time. 3 different time points were included in this study: pre-op (the blood was drawn right before the surgery started), post-op (at least 24Â h after surgery) and during the 2Â week follow-up (F/U) with the neurosurgeon. We show that the level of HOTAIR decreases after surgery and at the follow-up visit. (PDF 430Â kb)
Supplementary materials and methods. (DOCX 109Â kb)
Neuro-Oncology, 2021
Glioblastoma (GBM) remains the most common adult brain cancer, with a dismal average patient surv... more Glioblastoma (GBM) remains the most common adult brain cancer, with a dismal average patient survival of less than two years. No new treatments have been approved for GBM since the introduction of the alkylating agent temozolomide in 2005. Even then, temozolomide treatment only increases the average survival of GBM patients by a few months. Thus, novel therapeutic options are direly needed. The aurora kinases A and B are targetable and overexpressed in GBM, and their expression is highly correlated with patient survival outcomes. Our lab has found that small molecule aurora kinase inhibition reduces GBM tumor growth in vitro and in vivo, however, eventually tumors still grow. Computational analysis integrating compound transcriptional response signatures from the LINCS L1000 dataset with the single-cell RNA-sequencing data of patient GBM tumors resected at the University of Miami predicts that aurora inhibition targets a subset of cells present within any GBM tumor. Results of in vi...
Journal of Clinical Neuroscience, 2021
Background: During the coronavirus 19 (COVID-19) pandemic, physicians have begun adapting their d... more Background: During the coronavirus 19 (COVID-19) pandemic, physicians have begun adapting their daily practices to prevent transmissions. In this study we aimed to provide surgical neuro-oncologists with practice guidelines during the COVID-19 pandemic based on objective data from a high-volume brain tumor surgeon at the current COVID-19 epicenter. Methods: All outpatient visits and surgeries performed by the senior author during the COVID-19 pandemic were compared between the initial quarantine (3/23/20-5/4/20), the plateau period following quarantine (5/5/20-6/27/20), and the second peak (6/28/20-7/20/20). In-person and telemedicine visits were evaluated for crossovers. Surgeries were subdivided based on lesion type and evaluated across the same time period. Results: From 3/23/20-7/20/20, 469 clinic visits and 196 surgeries were identified. After quarantine was lifted, face-to-face visits increased (P < 0.01) yet no change in telehealth visits occurred. Of 327 telehealth visits, only 5.8% converted to in-person during the 4-month period with the most cited reason being patient preference (68.4%). Of the 196 surgeries performed during the pandemic, 29.1% occurred during quarantine, 49.0% during the plateau, and 21.9% occurred in the second peak. No COVID negative patients developed symptoms at follow-up. 55.6% were performed on malignant tumors and 31.6% were benign with no difference in case volumes throughout the pandemic. Conclusions: Despite exceptional challenges, we have maintained a high-volume surgical neuro-oncology practice at the epicenter of the COVID-19 pandemic. We provide the protocols implemented at our institution in order to maximize neuro-oncology care while mitigating risk of COVID-19 exposure to both patients and providers.
Journal of Neuro-Oncology, 2020
Background The most recent cIMPACT-NOW update highlighted the homozygous deletion of the Cyclin D... more Background The most recent cIMPACT-NOW update highlighted the homozygous deletion of the Cyclin Dependent Kinase Inhibitor 2A (CDKN2A) gene as a clinically important molecular alteration in IDH-mutant glioma. Correspondingly, we systematically reviewed the contemporary literature to affirm the contemporary stance of the literature on the prognostic significance of this alteration in this setting based on the current World Health Organization (WHO) Grade classification. Methods A systematic search of seven electronic databases from inception to February 2020 was conducted following PRISMA guidelines. Articles were screened against pre-specified criteria to include lower-grade glioma (LGG, WHO Grade II/III) and glioblastoma (GBM, WHO Grade IV) separately. Progression free survival (PFS) and overall survival (OS) from Kaplan-Meier and multivariable analyses were outcomes of interest. Results Nine institutional studies describing 2193 IDH-mutant gliomas satisfied criteria for evaluation, with 1756 (80%) LGG and 437 (20%) GBM. When reported, the proportion of CDKN2A homozygous deleted gliomas ranged from 9 to 43%, with a median incidence of 22%. For LGG, Kaplan-Meier analyses demonstrated shorter PFS in the presence of CDKN2A homozygous deletion in three studies (median values, 31 versus 91 months), and shorter OS in five studies (median values, 61 versus 154 months). For GBM, Kaplan-Meier analyses demonstrated shorter PFS in the presence of CDKN2A homozygous deletion in two studies (median values, 16 versus 30 months), and shorter OS in four studies (median values, 38 versus 86 months). By multivariable analyses, CDKN2A homozygous deletion was a predictor of significantly shorter PFS and OS in both LGG and GBM across all included studies. Conclusions The CDKN2A homozygous deletion is an important prognostic factor for survival outcomes of IDH-mutant glioma patients across multiple histologic WHO grades with specific molecular features likely dependent on IDH-mutant status. Greater understanding of how identifying this deletion can assist in the stratification of management for these tumors to optimize clinical course is required.
Journal of Neurological Surgery Part B: Skull Base, Feb 1, 2018
Journal of Neurological Surgery Part B: Skull Base, 2017
Neuro-Oncology
INTRODUCTION Until recent decades, thalamic gliomas had been considered largely inoperable. These... more INTRODUCTION Until recent decades, thalamic gliomas had been considered largely inoperable. These lesions are deep-seated and surrounded by vital structures. However, as technology and imaging modalities have improved, so have treatment modalities. Currently, a range of surgical approaches are used, partially dependent on the location of the lesion; although no consensus has been reached regarding optimal surgical management. OBJECTIVE To conduct a systematic review of the literature to describe the current surgical outcomes of adult thalamic gliomas. METHODS Four databases were searched with keywords “‘thalamic glioma’ AND ‘surgical intervention’ OR ‘thalamic glioma’ AND ‘surgical treatment’” for articles assessing surgical techniques of adult thalamic glioma resection. Our systematic review was reported in accordance with the PRISMA guidelines. 793 full-text studies were assessed for eligibility. Ultimately, 14 studies were included. RESULTS The mean age was of 33.57 years (18-83)...
Neuro-Oncology
INTRODUCTION Adult midline gliomas are rare entities, with a scarcity of available clinical data.... more INTRODUCTION Adult midline gliomas are rare entities, with a scarcity of available clinical data. These patients have variable courses, with limited evidence to predict outcomes. Emerging evidence suggests that biomolecular profiles may play a significant role in outcomes, so tissue diagnosis is a key component of management. However, the role of cytoreductive therapy, such as Laser Interstitial Thermal Therapy (LITT) remains unknown. To date, only a few studies have described the use of MRI-guided LITT for managing midline gliomas. OBJECTIVE To present a retrospective analysis of a single-center two-surgeon experience treating adult midline gliomas with either biopsy/LITT or biopsy alone. METHODS Patients with midline intraxial tumors surgically treated at our tertiary care referral center were identified using our established database. Twenty-one patients managed either with biopsy/LITT or needle biopsy from 2015 to 2021 were included. Demographics and clinical records including, ...
Neuro-Oncology
INTRODUCTION Increased levels of adhesion G Protein-Coupled Receptor(GPCR) CD97 have been detecte... more INTRODUCTION Increased levels of adhesion G Protein-Coupled Receptor(GPCR) CD97 have been detected in multiple metastatic cancers. Glioblastoma(GBM), also overexpress this receptor, and its levels positively correlate with more aggressive GBM invasion. Here, using primary human GBM cells we investigated the effects of CD97 knockdown and overexpression in-vitro and in-vivo. METHODS CD97 consists of two distinct domains: the large extracellular fragment interacting with ECM and other cell surface receptors and the GPCR core that activates heterotrimeric G Proteins G12/13. To investigate the mechanism of action of CD97, we generated a CD97 knockdown (shCD97) and overexpression (CD97-WT) constructs. Additionally, we generated two functional mutants: a constitutively active mutant lacking the N-Terminus (dNTF) and dominant-negative mutant (H436A) that cannot activate G-Proteins downstream. Glioma Stem Cells(GSC) were transduced by control and CD97 lentiviral constructs and implanted into...
Neuro-Oncology
INTRODUCTION Brain metastases from uterine origin have an incidence of 0.7-1.1%. Due to their rar... more INTRODUCTION Brain metastases from uterine origin have an incidence of 0.7-1.1%. Due to their rarity, there exists scarce literature entailing their neurosurgical treatment and outcomes. OBJECTIVE To report case management and outcomes of nine patients with brain metastases from uterine origin, as well as a systematic literature review findings focused on their neurosurgical treatment and outcomes. METHODS This study was divided into two parts: (1) a retrospective, single-center patient series assessing neurosurgical outcomes in patients with primary uterine cancer with brain metastases and (2) a systematic review of the literature between 1980 and 2021 assessing outcomes of patients with primary uterine cancer metastasized to the brain. RESULTS We report a case series at our single institution consisting of nine patients identified to have metastases to the brain from uterine origin that were treated with neurosurgical intervention. A total of 26 CNS lesions were identified among t...
Loss of hand function after cervical spinal cord injury severely impairs functional independence.... more Loss of hand function after cervical spinal cord injury severely impairs functional independence. We describe a method for restoring volitional control of hand grasp in a subject with complete cervical quadriplegia (C5 ASIA Impairment Scale A) using a portable fully implanted brain-computer interface (BCI) within the home environment. The BCI consists of subdural surface electrodes placed over the dominant-hand motor cortex and connects to a transmitter implanted subcutaneously below the clavicle, which allows continuous reading of the electrocorticographic (ECoG) activity. Movement-intent was used to trigger functional electrical stimulation (FES) of the dominant hand during an initial 29-week laboratory study and subsequently via a mechanical hand orthosis during in-home use. Movement intent information could be decoded consistently throughout the 29-week in-laboratory study with a mean accuracy of 89.0% (range 78-93.3%). Improvements were observed in both the speed and accuracy o...
World Neurosurgery, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
World Neurosurgery, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Neuro-Oncology
BACKGROUND AND PURPOSE The goal of this study was to systematically review the existing literatur... more BACKGROUND AND PURPOSE The goal of this study was to systematically review the existing literature on neurosurgical management and outcomes of brain metastasis from pancreatic cáncer in comparison to our institutional experience of this patient cohort. METHODS Following the PRISMA guidelines, a systematic literature review was performed using PubMed, Ovid Embase, Scopus, and Web of Science databases from date of database inception to January 2022. Studies were selected based on predetermined inclusion and exclusión criteria. Simulteanously, a retrospective analysis was conducted on patients who underwent neurosurgical evaluation and treatment for intracranial metastatic lesions from pancreatic origin at a single institution. RESULTS Of the total 292 articles in the original literature search, 17 studies were ultimately selected. A total of 23 patients with brain metastases of pancreatic origin were included. Median overall survival from original diagnosis of pancreatic cancer was 22...
Neuro-Oncology
INTRODUCTION The concept of enhanced recovery after surgery (ERAS) due to standardized interventi... more INTRODUCTION The concept of enhanced recovery after surgery (ERAS) due to standardized interventions has been gaining more relevance within neurosurgery. Advances were made both in protocols for spine and cranial surgery. These experiences described many benefits such as less psychological stress, reduction in hospitalization days, and lower hospital costs, without increasing the incidence of complications. However, no experience has described to date the applicability of an ERAS program for laser ablation thermal therapy (LITT). OBJECTIVE To describe our initial experience with the first enhanced recovery program reported for laser ablation for brain tumors. Secondly, to summarize the perioperative clinical outcomes of ERAS applied to LITT. METHODS We performed a retrospective analysis of all adult patients who underwent LITT for oncological lesions from 2013 to 2021. A multidisciplinary program was created by protocolizing interventions carried out along the path of the patient...
Operative Neurosurgery, 2020
Figure S2. A longitudinal study on a single GBM patient was carried out in order to monitor the c... more Figure S2. A longitudinal study on a single GBM patient was carried out in order to monitor the changes in serum HOTAIR expression over time. 3 different time points were included in this study: pre-op (the blood was drawn right before the surgery started), post-op (at least 24Â h after surgery) and during the 2Â week follow-up (F/U) with the neurosurgeon. We show that the level of HOTAIR decreases after surgery and at the follow-up visit. (PDF 430Â kb)
Supplementary materials and methods. (DOCX 109Â kb)
Neuro-Oncology, 2021
Glioblastoma (GBM) remains the most common adult brain cancer, with a dismal average patient surv... more Glioblastoma (GBM) remains the most common adult brain cancer, with a dismal average patient survival of less than two years. No new treatments have been approved for GBM since the introduction of the alkylating agent temozolomide in 2005. Even then, temozolomide treatment only increases the average survival of GBM patients by a few months. Thus, novel therapeutic options are direly needed. The aurora kinases A and B are targetable and overexpressed in GBM, and their expression is highly correlated with patient survival outcomes. Our lab has found that small molecule aurora kinase inhibition reduces GBM tumor growth in vitro and in vivo, however, eventually tumors still grow. Computational analysis integrating compound transcriptional response signatures from the LINCS L1000 dataset with the single-cell RNA-sequencing data of patient GBM tumors resected at the University of Miami predicts that aurora inhibition targets a subset of cells present within any GBM tumor. Results of in vi...
Journal of Clinical Neuroscience, 2021
Background: During the coronavirus 19 (COVID-19) pandemic, physicians have begun adapting their d... more Background: During the coronavirus 19 (COVID-19) pandemic, physicians have begun adapting their daily practices to prevent transmissions. In this study we aimed to provide surgical neuro-oncologists with practice guidelines during the COVID-19 pandemic based on objective data from a high-volume brain tumor surgeon at the current COVID-19 epicenter. Methods: All outpatient visits and surgeries performed by the senior author during the COVID-19 pandemic were compared between the initial quarantine (3/23/20-5/4/20), the plateau period following quarantine (5/5/20-6/27/20), and the second peak (6/28/20-7/20/20). In-person and telemedicine visits were evaluated for crossovers. Surgeries were subdivided based on lesion type and evaluated across the same time period. Results: From 3/23/20-7/20/20, 469 clinic visits and 196 surgeries were identified. After quarantine was lifted, face-to-face visits increased (P < 0.01) yet no change in telehealth visits occurred. Of 327 telehealth visits, only 5.8% converted to in-person during the 4-month period with the most cited reason being patient preference (68.4%). Of the 196 surgeries performed during the pandemic, 29.1% occurred during quarantine, 49.0% during the plateau, and 21.9% occurred in the second peak. No COVID negative patients developed symptoms at follow-up. 55.6% were performed on malignant tumors and 31.6% were benign with no difference in case volumes throughout the pandemic. Conclusions: Despite exceptional challenges, we have maintained a high-volume surgical neuro-oncology practice at the epicenter of the COVID-19 pandemic. We provide the protocols implemented at our institution in order to maximize neuro-oncology care while mitigating risk of COVID-19 exposure to both patients and providers.
Journal of Neuro-Oncology, 2020
Background The most recent cIMPACT-NOW update highlighted the homozygous deletion of the Cyclin D... more Background The most recent cIMPACT-NOW update highlighted the homozygous deletion of the Cyclin Dependent Kinase Inhibitor 2A (CDKN2A) gene as a clinically important molecular alteration in IDH-mutant glioma. Correspondingly, we systematically reviewed the contemporary literature to affirm the contemporary stance of the literature on the prognostic significance of this alteration in this setting based on the current World Health Organization (WHO) Grade classification. Methods A systematic search of seven electronic databases from inception to February 2020 was conducted following PRISMA guidelines. Articles were screened against pre-specified criteria to include lower-grade glioma (LGG, WHO Grade II/III) and glioblastoma (GBM, WHO Grade IV) separately. Progression free survival (PFS) and overall survival (OS) from Kaplan-Meier and multivariable analyses were outcomes of interest. Results Nine institutional studies describing 2193 IDH-mutant gliomas satisfied criteria for evaluation, with 1756 (80%) LGG and 437 (20%) GBM. When reported, the proportion of CDKN2A homozygous deleted gliomas ranged from 9 to 43%, with a median incidence of 22%. For LGG, Kaplan-Meier analyses demonstrated shorter PFS in the presence of CDKN2A homozygous deletion in three studies (median values, 31 versus 91 months), and shorter OS in five studies (median values, 61 versus 154 months). For GBM, Kaplan-Meier analyses demonstrated shorter PFS in the presence of CDKN2A homozygous deletion in two studies (median values, 16 versus 30 months), and shorter OS in four studies (median values, 38 versus 86 months). By multivariable analyses, CDKN2A homozygous deletion was a predictor of significantly shorter PFS and OS in both LGG and GBM across all included studies. Conclusions The CDKN2A homozygous deletion is an important prognostic factor for survival outcomes of IDH-mutant glioma patients across multiple histologic WHO grades with specific molecular features likely dependent on IDH-mutant status. Greater understanding of how identifying this deletion can assist in the stratification of management for these tumors to optimize clinical course is required.
Journal of Neurological Surgery Part B: Skull Base, Feb 1, 2018
Journal of Neurological Surgery Part B: Skull Base, 2017
Neuro-Oncology
INTRODUCTION Until recent decades, thalamic gliomas had been considered largely inoperable. These... more INTRODUCTION Until recent decades, thalamic gliomas had been considered largely inoperable. These lesions are deep-seated and surrounded by vital structures. However, as technology and imaging modalities have improved, so have treatment modalities. Currently, a range of surgical approaches are used, partially dependent on the location of the lesion; although no consensus has been reached regarding optimal surgical management. OBJECTIVE To conduct a systematic review of the literature to describe the current surgical outcomes of adult thalamic gliomas. METHODS Four databases were searched with keywords “‘thalamic glioma’ AND ‘surgical intervention’ OR ‘thalamic glioma’ AND ‘surgical treatment’” for articles assessing surgical techniques of adult thalamic glioma resection. Our systematic review was reported in accordance with the PRISMA guidelines. 793 full-text studies were assessed for eligibility. Ultimately, 14 studies were included. RESULTS The mean age was of 33.57 years (18-83)...
Neuro-Oncology
INTRODUCTION Adult midline gliomas are rare entities, with a scarcity of available clinical data.... more INTRODUCTION Adult midline gliomas are rare entities, with a scarcity of available clinical data. These patients have variable courses, with limited evidence to predict outcomes. Emerging evidence suggests that biomolecular profiles may play a significant role in outcomes, so tissue diagnosis is a key component of management. However, the role of cytoreductive therapy, such as Laser Interstitial Thermal Therapy (LITT) remains unknown. To date, only a few studies have described the use of MRI-guided LITT for managing midline gliomas. OBJECTIVE To present a retrospective analysis of a single-center two-surgeon experience treating adult midline gliomas with either biopsy/LITT or biopsy alone. METHODS Patients with midline intraxial tumors surgically treated at our tertiary care referral center were identified using our established database. Twenty-one patients managed either with biopsy/LITT or needle biopsy from 2015 to 2021 were included. Demographics and clinical records including, ...
Neuro-Oncology
INTRODUCTION Increased levels of adhesion G Protein-Coupled Receptor(GPCR) CD97 have been detecte... more INTRODUCTION Increased levels of adhesion G Protein-Coupled Receptor(GPCR) CD97 have been detected in multiple metastatic cancers. Glioblastoma(GBM), also overexpress this receptor, and its levels positively correlate with more aggressive GBM invasion. Here, using primary human GBM cells we investigated the effects of CD97 knockdown and overexpression in-vitro and in-vivo. METHODS CD97 consists of two distinct domains: the large extracellular fragment interacting with ECM and other cell surface receptors and the GPCR core that activates heterotrimeric G Proteins G12/13. To investigate the mechanism of action of CD97, we generated a CD97 knockdown (shCD97) and overexpression (CD97-WT) constructs. Additionally, we generated two functional mutants: a constitutively active mutant lacking the N-Terminus (dNTF) and dominant-negative mutant (H436A) that cannot activate G-Proteins downstream. Glioma Stem Cells(GSC) were transduced by control and CD97 lentiviral constructs and implanted into...
Neuro-Oncology
INTRODUCTION Brain metastases from uterine origin have an incidence of 0.7-1.1%. Due to their rar... more INTRODUCTION Brain metastases from uterine origin have an incidence of 0.7-1.1%. Due to their rarity, there exists scarce literature entailing their neurosurgical treatment and outcomes. OBJECTIVE To report case management and outcomes of nine patients with brain metastases from uterine origin, as well as a systematic literature review findings focused on their neurosurgical treatment and outcomes. METHODS This study was divided into two parts: (1) a retrospective, single-center patient series assessing neurosurgical outcomes in patients with primary uterine cancer with brain metastases and (2) a systematic review of the literature between 1980 and 2021 assessing outcomes of patients with primary uterine cancer metastasized to the brain. RESULTS We report a case series at our single institution consisting of nine patients identified to have metastases to the brain from uterine origin that were treated with neurosurgical intervention. A total of 26 CNS lesions were identified among t...
Loss of hand function after cervical spinal cord injury severely impairs functional independence.... more Loss of hand function after cervical spinal cord injury severely impairs functional independence. We describe a method for restoring volitional control of hand grasp in a subject with complete cervical quadriplegia (C5 ASIA Impairment Scale A) using a portable fully implanted brain-computer interface (BCI) within the home environment. The BCI consists of subdural surface electrodes placed over the dominant-hand motor cortex and connects to a transmitter implanted subcutaneously below the clavicle, which allows continuous reading of the electrocorticographic (ECoG) activity. Movement-intent was used to trigger functional electrical stimulation (FES) of the dominant hand during an initial 29-week laboratory study and subsequently via a mechanical hand orthosis during in-home use. Movement intent information could be decoded consistently throughout the 29-week in-laboratory study with a mean accuracy of 89.0% (range 78-93.3%). Improvements were observed in both the speed and accuracy o...
World Neurosurgery, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
World Neurosurgery, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.