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Simons M, Fisher G, Spanos S, Zurynski Y, Davidson A, Stoodley M, Rapport F, Ellis LA. Integrating training in evidence-based medicine and shared decision-making: a qualitative study of junior doctors and consultants. BMC Med Educ 2024; 24:418. [PMID: 38637798 PMCID: PMC11027546 DOI: 10.1186/s12909-024-05409-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 04/09/2024] [Indexed: 04/20/2024]
Abstract
BACKGROUND In the past, evidence-based medicine (EBM) and shared decision-making (SDM) have been taught separately in health sciences and medical education. However, recognition is increasing of the importance of EBM training that includes SDM, whereby practitioners incorporate all steps of EBM, including person-centered decision-making using SDM. However, there are few empirical investigations into the benefits of training that integrates EBM and SDM (EBM-SDM) for junior doctors, and their influencing factors. This study aimed to explore how integrated EBM-SDM training can influence junior doctors' attitudes to and practice of EBM and SDM; to identify the barriers and facilitators associated with junior doctors' EBM-SDM learning and practice; and to examine how supervising consultants' attitudes and authority impact on junior doctors' opportunities for EBM-SDM learning and practice. METHODS We developed and ran a series of EBM-SDM courses for junior doctors within a private healthcare setting with protected time for educational activities. Using an emergent qualitative design, we first conducted pre- and post-course semi-structured interviews with 12 junior doctors and thematically analysed the influence of an EBM-SDM course on their attitudes and practice of both EBM and SDM, and the barriers and facilitators to the integrated learning and practice of EBM and SDM. Based on the responses of junior doctors, we then conducted interviews with ten of their supervising consultants and used a second thematic analysis to understand the influence of consultants on junior doctors' EBM-SDM learning and practice. RESULTS Junior doctors appreciated EBM-SDM training that involved patient participation. After the training course, they intended to improve their skills in person-centered decision-making including SDM. However, junior doctors identified medical hierarchy, time factors, and lack of prior training as barriers to the learning and practice of EBM-SDM, whilst the private healthcare setting with protected learning time and supportive consultants were considered facilitators. Consultants had mixed attitudes towards EBM and SDM and varied perceptions of the role of junior doctors in either practice, both of which influenced the practice of junior doctors. CONCLUSIONS These findings suggested that future medical education and research should include training that integrates EBM and SDM that acknowledges the complex environment in which this training must be put into practice, and considers strategies to overcome barriers to the implementation of EBM-SDM learning in practice.
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Affiliation(s)
- Mary Simons
- Centre for Healthcare Resilience and Implementation Science, Australian Institute of Health Innovation, Macquarie University, Sydney, NSW, 2109, Australia.
- Australian Institute of Health Innovation, 75 Talavera Rd, Macquarie Park, NSW, 2109, Australia.
| | - Georgia Fisher
- Centre for Healthcare Resilience and Implementation Science, Australian Institute of Health Innovation, Macquarie University, Sydney, NSW, 2109, Australia
| | - Samantha Spanos
- Centre for Healthcare Resilience and Implementation Science, Australian Institute of Health Innovation, Macquarie University, Sydney, NSW, 2109, Australia
| | - Yvonne Zurynski
- Centre for Healthcare Resilience and Implementation Science, Australian Institute of Health Innovation, Macquarie University, Sydney, NSW, 2109, Australia
| | - Andrew Davidson
- Department of Neurosurgery, The Royal Melbourne Hospital, Parkville, VIC, 3050, Australia
| | - Marcus Stoodley
- Department of Clinical Medicine, Macquarie University, Sydney, NSW, 2109, Australia
| | - Frances Rapport
- Centre for Healthcare Resilience and Implementation Science, Australian Institute of Health Innovation, Macquarie University, Sydney, NSW, 2109, Australia
| | - Louise A Ellis
- Centre for Healthcare Resilience and Implementation Science, Australian Institute of Health Innovation, Macquarie University, Sydney, NSW, 2109, Australia
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Agarwal N, Lewis LD, Hirschler L, Rivera LR, Naganawa S, Levendovszky SR, Ringstad G, Klarica M, Wardlaw J, Iadecola C, Hawkes C, Octavia Carare R, Wells J, Bakker EN, Kurtcuoglu V, Bilston L, Nedergaard M, Mori Y, Stoodley M, Alperin N, de Leon M, van Osch MJ. Current Understanding of the Anatomy, Physiology, and Magnetic Resonance Imaging of Neurofluids: Update From the 2022 "ISMRM Imaging Neurofluids Study group" Workshop in Rome. J Magn Reson Imaging 2024; 59:431-449. [PMID: 37141288 PMCID: PMC10624651 DOI: 10.1002/jmri.28759] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/18/2023] [Accepted: 04/18/2023] [Indexed: 05/05/2023] Open
Abstract
Neurofluids is a term introduced to define all fluids in the brain and spine such as blood, cerebrospinal fluid, and interstitial fluid. Neuroscientists in the past millennium have steadily identified the several different fluid environments in the brain and spine that interact in a synchronized harmonious manner to assure a healthy microenvironment required for optimal neuroglial function. Neuroanatomists and biochemists have provided an incredible wealth of evidence revealing the anatomy of perivascular spaces, meninges and glia and their role in drainage of neuronal waste products. Human studies have been limited due to the restricted availability of noninvasive imaging modalities that can provide a high spatiotemporal depiction of the brain neurofluids. Therefore, animal studies have been key in advancing our knowledge of the temporal and spatial dynamics of fluids, for example, by injecting tracers with different molecular weights. Such studies have sparked interest to identify possible disruptions to neurofluids dynamics in human diseases such as small vessel disease, cerebral amyloid angiopathy, and dementia. However, key differences between rodent and human physiology should be considered when extrapolating these findings to understand the human brain. An increasing armamentarium of noninvasive MRI techniques is being built to identify markers of altered drainage pathways. During the three-day workshop organized by the International Society of Magnetic Resonance in Medicine that was held in Rome in September 2022, several of these concepts were discussed by a distinguished international faculty to lay the basis of what is known and where we still lack evidence. We envision that in the next decade, MRI will allow imaging of the physiology of neurofluid dynamics and drainage pathways in the human brain to identify true pathological processes underlying disease and to discover new avenues for early diagnoses and treatments including drug delivery. Evidence level: 1 Technical Efficacy: Stage 3.
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Affiliation(s)
- Nivedita Agarwal
- Neuroradiology Unit, Scientific Institute IRCCS E. Medea, Bosisio Parini, Italy
| | - Laura D. Lewis
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Lydiane Hirschler
- C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Leonardo Rivera Rivera
- Wisconsin Alzheimer’s Disease Research Center, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - Shinji Naganawa
- Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | | | - Geir Ringstad
- Department of Radiology, Oslo University Hospital Rikshospitalet, Oslo, Norway
- Department of Geriatrics and Internal Medicine, Sorlandet Hospital, Arendal, Norway
| | - Marijan Klarica
- Department of Pharmacology and Croatian Institute of Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Joanna Wardlaw
- Centre for Clinical Brain Sciences and UK Dementia Research Institute Centre, University of Edinburgh, Edinburgh, UK
| | - Costantino Iadecola
- Department of Pharmacology and Croatian Institute of Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia
| | - Cheryl Hawkes
- Biomedical and Life Sciences, Lancaster University, Lancaster, UK
| | | | - Jack Wells
- UCL Centre for Advanced Biomedical Imaging, University College of London, London, UK
| | - Erik N.T.P. Bakker
- Biomedical Engineering and Physics, Amsterdam UMC, University of Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | | | - Lynne Bilston
- Neuroscience Research Australia and UNSW Medicine, Sydney, Australia
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York, USA
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Yuki Mori
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Marcus Stoodley
- Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
- Department of Neurosurgery, Macquarie University Hospital, Sydney, Australia
| | - Noam Alperin
- Department of Radiology and Biomedical Engineering, Miller School of Medicine, University of Miami, Miami, Florida, USA
| | - Mony de Leon
- Weil Cornell Medicine, Department of Radiology, Brain Health Imaging Institute, New York City, New York, USA
| | - Matthias J.P. van Osch
- C.J. Gorter MRI Center, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
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Mariadas R, Liu S, Sachdeva M, Unnikrishnan S, Foong HY, Stoodley M. Revascularization Surgery for Moyamoya Vasculopathy: An Australian Experience. World Neurosurg 2023; 178:e65-e71. [PMID: 37419316 DOI: 10.1016/j.wneu.2023.06.129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/25/2023] [Accepted: 06/26/2023] [Indexed: 07/09/2023]
Abstract
BACKGROUND Moyamoya vasculopathy is a rare steno-occlusive cerebrovascular disorder presenting with ischemia or hemorrhage. There are racial and geographic differences in presentation and outcome. There is little information regarding moyamoya in Australia. METHODS Moyamoya patients undergoing surgery from 2001 to 2022 were studied retrospectively. The outcomes of revascularization surgery in adult and pediatric patients, with ischemic and hemorrhagic disease were analyzed, including functional outcomes, postoperative complications, bypass patency, and long-term rates of ischemic and hemorrhagic events. RESULTS A total of 68 patients with 122 revascularized hemispheres and 8 posterior circulation revascularizations were included in this study. Eighteen patients were of Asian descent and 46 were of Caucasian origin. Presentation was with ischemia in 124 hemispheres and hemorrhage in six hemispheres. There were 92 direct, 34 indirect, and 4 combined revascularization surgeries performed. Early postoperative complications occurred in 3.1% (n = 4) of operations and delayed complications (infection, subdural hematoma) occurred after 4.6% (n = 6) of operations. Mean follow-up was 6.5 years (3-252 months). There was 100% patency of direct grafts at last follow-up. There were no hemorrhagic events following surgery and 1 new ischemic event 2 years after surgery. There was significant improvement in physical health functional outcomes at most recent follow-up (P < 0.05); mental health outcomes were not different between preoperative and postoperative assessments. CONCLUSIONS The majority of Australian moyamoya patients are Caucasian and the most common clinical presentation is ischemia. Revascularization surgery had excellent outcomes with very low rates of ischemia and hemorrhage, comparing favorably to the natural history of moyamoya vasculopathy.
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Affiliation(s)
- Rachael Mariadas
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, New South Wales, Australia
| | - Shinuo Liu
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, New South Wales, Australia
| | - Mugdha Sachdeva
- Department of Neurosurgery, Diakonie Klinikum Jung Stilling Hospital, Siegen, Germany
| | - Sunil Unnikrishnan
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, New South Wales, Australia
| | - Hui Yuan Foong
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, New South Wales, Australia
| | - Marcus Stoodley
- Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, New South Wales, Australia.
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Patabendige A, Vinje V, Stoodley M. Editorial: Cerebrospinal fluid dynamics and intracranial pressure elevation-Novel insights on molecular and physiological mechanisms, and implications for neurological disease. Front Mol Neurosci 2022; 15:1119980. [PMID: 36644618 PMCID: PMC9832444 DOI: 10.3389/fnmol.2022.1119980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 12/09/2022] [Indexed: 12/29/2022] Open
Affiliation(s)
- Adjanie Patabendige
- Brain Barriers Research Group, Department of Biology, Edge Hill University, Ormskirk, United Kingdom,The School of Biomedical Sciences and Pharmacy, The University of Newcastle, Newcastle, NSW, Australia,Department of Clinical Infection, Microbiology & Immunology, Institute of Infection, Veterinary, and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom,*Correspondence: Adjanie Patabendige ✉
| | - Vegard Vinje
- Simula Research Laboratory, Department of Numerical Analysis and Scientific Computing, Oslo, Norway
| | - Marcus Stoodley
- Neurosurgery Unit, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
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Simons M, Rapport F, Zurynski Y, Stoodley M, Cullis J, Davidson AS. Links between evidence-based medicine and shared decision-making in courses for doctors in training: a scoping review. BMJ Open 2022; 12:e057335. [PMID: 35470193 PMCID: PMC9039384 DOI: 10.1136/bmjopen-2021-057335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVES This scoping review aims to synthesise the current evidence on the inclusion and effectiveness of integrating evidence-based medicine (EBM) and shared decision-making (SDM) into training courses for doctors in training to enhance patient care. Both EBM and SDM appear to be taught separately and their combined role in providing high-quality patient care has not yet been explored. DESIGN Scoping review of literature from January 2017 to June 2021. SETTING Any setting where doctors in training could undertake EBM and/or SDM courses (hospitals, universities, clinics and online). PARTICIPANTS Doctors in training (also known as junior doctors, residents, registrars, trainees, fellows) defined as medical graduates undertaking further training to establish a career pathway. METHODS Searches were conducted in the databases Medline, Embase, Scopus and Cochrane Library. Bibliographies of included articles and their cited references were hand searched and assessed for inclusion. Included studies described training and outcomes of either EBM, SDM or both. Reported outcomes included EBM knowledge and skill tests, attitude surveys, SDM checklists and surveys and patient and doctor experience data obtained from surveys, focus groups and interviews. RESULTS Of the 26 included studies, 15 described EBM training courses, 10 described SDM training courses and 1 course combined both EBM and SDM. Courses were heterogeneous in their content and outcomes, making comparisons difficult. EBM courses prioritised quantitative outcome assessments and linked knowledge and skills, such as critical appraisal, but overlooked other key elements of patient-centred care including SDM. CONCLUSIONS SDM and EBM are taught separately in most training courses. The inclusion of SDM, evaluated by qualitative assessments, is currently omitted, yet could provide a more person-centred care focus in EBM courses and should be investigated to increase our knowledge of the effectiveness of such courses and their role in improving doctors' skills and patient care. PROTOCOL A protocol for this review has been published and contains further details of the methodology.
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Affiliation(s)
- Mary Simons
- Library, Macquarie University, Sydney, New South Wales, Australia
| | - Frances Rapport
- Australian Institute of Health Innovation, Macquarie University, Sydney, New South Wales, Australia
| | - Yvonne Zurynski
- Australian Institute of Health Innovation, Macquarie University, Sydney, New South Wales, Australia
| | - Marcus Stoodley
- Macquarie Neurosurgery & Spine, Macquarie University Faculty of Medicine Health and Human Sciences, Sydney, New South Wales, Australia
| | - Jeremy Cullis
- Library, Macquarie University, Sydney, New South Wales, Australia
| | - Andrew S Davidson
- Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
- Department of Neurosurgery, The Royal Melbourne Hospital City Campus, Parkville, Victoria, Australia
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Massimi L, Peretta P, Erbetta A, Solari A, Farinotti M, Ciaramitaro P, Saletti V, Caldarelli M, Canheu AC, Celada C, Chiapparini L, Chieffo D, Cinalli G, Di Rocco F, Furlanetto M, Giordano F, Jallo G, James S, Lanteri P, Lemarchand C, Messing-Jünger M, Parazzini C, Paternoster G, Piatelli G, Poca MA, Prabahkar P, Ricci F, Righini A, Sala F, Sahuquillo J, Stoodley M, Talamonti G, Thompson D, Triulzi F, Zucchelli M, Valentini L. Diagnosis and treatment of Chiari malformation type 1 in children: the International Consensus Document. Neurol Sci 2022; 43:1311-1326. [PMID: 34097175 PMCID: PMC8789635 DOI: 10.1007/s10072-021-05317-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 05/08/2021] [Indexed: 12/21/2022]
Abstract
BACKGROUND Chiari malformation type 1 (CM1) is a rare condition where agreed classification and treatment are still missing. The goal of this study is to achieve a consensus on the diagnosis and treatment of CM1 in children. METHODS A multidisciplinary panel formulated 57 provisional statements based on a review of the literature. Thirty-four international experts (IE) participated in a Delphi study by independently rating each statement on a 4-point Likert scale ("strongly disagree," "disagree," "agree," "strongly agree"). Statements that were endorsed ("agree" or "strongly agree") by < 75% of raters were re-formulated, or new statements were added, and another Delphi round followed (up to a maximum of three). RESULTS Thirty-five IE were contacted and 34 agreed to participate. A consensus was reached on 30/57 statements (52.6%) after round 1. Three statements were added, and one removed. After round 2, agreement was reached on 56/59 statements (94.9%). Finally, after round 3, which took place during the 2019 Chiari Consensus Conference (Milan, Italy), agreement was reached on 58/59 statements (98.3%) about four main sections (Definition and Classification, Planning, Surgery, Isolated Syringomyelia). Only one statement did not gain a consensus, which is the "definition of radiological failure 24 month post-surgery." CONCLUSIONS The consensus document consists of 58 statements (24 on diagnosis, 34 on treatment), serving clinicians and researchers following children with CM1. There is a clear need for establishing an international network and registry and to promote collaborative studies to increase the evidence base and optimize the long-term care of this patient population.
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Affiliation(s)
- Luca Massimi
- Pediatric Neurosurgery, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo A. Gemelli, 8, 00168, Rome, Italy.
| | - Paola Peretta
- Pediatric Neurosurgery, AOU Citta' della Salute e della Scienza di Torino, Torino, Italy
| | - Alessandra Erbetta
- Department of Neuroradiology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Alessandra Solari
- Neuroepidemiology Unit - Scientific Directorate, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Mariangela Farinotti
- Neuroepidemiology Unit - Scientific Directorate, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Palma Ciaramitaro
- Department of Neuroscience, AOU Citta' della Salute e della Scienza di Torino, Torino, Italy
| | - Veronica Saletti
- Department of Pediatric Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Massimo Caldarelli
- Pediatric Neurosurgery, Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo A. Gemelli, 8, 00168, Rome, Italy
| | | | - Carlo Celada
- "Associazione Italiana Siringomielia e Arnold Chiari", Garino, Italy
| | - Luisa Chiapparini
- Department of Neuroradiology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Daniela Chieffo
- Clinical Psychology Unit, Fondazione Policlinico Universitario A Gemelli IRCCS and UCSC, Rome, Italy
| | - Giuseppe Cinalli
- Pediatric Neurosurgery, Santobono-Pausilipon Children's Hospital, Naples, Italy
| | - Federico Di Rocco
- Pediatric Neurosurgery Department, Université de Lyon, INSERM U1033, Hopital Femme Mère Enfant, Lyon, France
| | - Marika Furlanetto
- Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Flavio Giordano
- Department of Neurosurgery, Meyer Pediatric Hospital, Florence, Italy
| | - George Jallo
- Institute for Brain Protection Sciences, Johns Hopkins All Children's Hospital, St. Petersburg, FL, USA
| | - Syril James
- Department of Pediatric Neurosurgery, Necker Enfants Malades Hospital, Paris, France
| | - Paola Lanteri
- Department of Diagnostic and Technology, Neurophysiopathology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | | | | | - Cecilia Parazzini
- Department of Pediatric Radiology and Neuroradiology, Children Hospital V. Buzzi, Milan, Italy
| | - Giovanna Paternoster
- Department of Pediatric Neurosurgery, Necker Enfants Malades Hospital, Paris, France
| | - Gianluca Piatelli
- Department of Neurosurgery, Gaslini Children's Hospital, Genoa, Italy
| | - Maria A Poca
- Neurosurgery and Pediatric Neurosurgery, Vall d'Hebron Hospital Universitari, Neurotrauma and Neurosurgery Research Unit, and Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Prab Prabahkar
- Department of Neurology, Great Ormond Street Hospital for Children, London, UK
| | - Federica Ricci
- Pediatric Neuropsychiatric Unit, AOU Citta' della Salute e della Scienza di Torino, Torino, Italy
| | - Andrea Righini
- Department of Pediatric Radiology and Neuroradiology, Children Hospital V. Buzzi, Milan, Italy
| | - Francesco Sala
- Section of Neurosurgery, Department of Neurosciences, Biomedicine and Movement Sciences, University Hospital, Verona, Italy
| | - Juan Sahuquillo
- Neurosurgery and Pediatric Neurosurgery, Vall d'Hebron Hospital Universitari, Neurotrauma and Neurosurgery Research Unit, and Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Marcus Stoodley
- Department of Clinical Medicine, Macquarie University Clinical Associates, Sidney, Australia
| | | | - Dominic Thompson
- Department of Neurosurgery, Great Ormond Street Hospital for Children, London, UK
| | - Fabio Triulzi
- Department of Pathophysiology and Transplantation, Neuroradiology Unit, University of Milan, Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Mino Zucchelli
- Neurochirurgia Pediatrica, IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Laura Valentini
- Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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Ciaramitaro P, Massimi L, Bertuccio A, Solari A, Farinotti M, Peretta P, Saletti V, Chiapparini L, Barbanera A, Garbossa D, Bolognese P, Brodbelt A, Celada C, Cocito D, Curone M, Devigili G, Erbetta A, Ferraris M, Furlanetto M, Gilanton M, Jallo G, Karadjova M, Klekamp J, Massaro F, Morar S, Parker F, Perrini P, Poca MA, Sahuquillo J, Stoodley M, Talamonti G, Triulzi F, Valentini MC, Visocchi M, Valentini L. Correction to: Diagnosis and treatment of Chiari Malformation and syringomyelia in adults: International Consensus Document. Neurol Sci 2021; 43:1483-1484. [PMID: 34786631 DOI: 10.1007/s10072-021-05724-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Palma Ciaramitaro
- CRESSC, SSD Coordinamento Neurofisiologia Clinica and Neurosurgery Unit, Department of Neuroscience, University of Torino, Torino, Italy. .,Neuroscience Dpt, Azienda Ospedaliero-Universitaria Città della Salute e della Scienza di Torino, Presidio CTO, via Zuretti, 29, Torino, Italy.
| | - Luca Massimi
- Pediatric Neurosurgery, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Alessandro Bertuccio
- Department of Neurosurgery, "SS Antonio e Biagio e Cesare Arrigo" Hospital, Alessandria, Italy
| | - Alessandra Solari
- Neuroepidemiology Unit - Scientific Directorate, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Mariangela Farinotti
- Neuroepidemiology Unit - Scientific Directorate, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Paola Peretta
- Pediatric Neurosurgery, Ospedale Infantile ReginaMargherita, AOU Citta' della Salute e della Scienza di Torino, Torino, Italy
| | - Veronica Saletti
- Developmental Neurology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Luisa Chiapparini
- Department of Neuroradiology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Andrea Barbanera
- Department of Neurosurgery, "SS Antonio e Biagio e Cesare Arrigo" Hospital, Alessandria, Italy
| | - Diego Garbossa
- CRESSC, SSD Coordinamento Neurofisiologia Clinica and Neurosurgery Unit, Department of Neuroscience, University of Torino, Torino, Italy
| | - Paolo Bolognese
- Chiari Neuosurgical Center, Mount Sinai, South Nassau, Oceanside, NY, USA
| | - Andrew Brodbelt
- Consultant Neurosurgeon, The Walton Centre NHS Foundation Trust, Liverpool, UK
| | | | - Dario Cocito
- Istituti Clinici Scientifici Maugeri, Torino, Italy
| | - Marcella Curone
- Casa di Cura del Policlinico, Igea Headache Center, Milan, Italy
| | - Grazia Devigili
- Department of Clinical Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Alessandra Erbetta
- Service of Neuroradiology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Marilena Ferraris
- Service of Neuroradiology, Diagnostic Imaging Department, AOU Citta' della Salute e della Scienza di Torino, Torino, Italy
| | - Marika Furlanetto
- Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | | | - George Jallo
- Johns Hopkins University Department of Neurosurgery, Johns Hopkins Hospital, Baltimore, MD, USA
| | | | - Jorg Klekamp
- Christliches Krankenhaus Quakenbrück, Department of Neurosurgery, Quakenbrück, Germany
| | - Fulvio Massaro
- Department of Neurosurgery, University of Torino, Torino, Italy
| | - Sylvia Morar
- Neurosurgery Department, Reference Center Rares Diseases C-MAVEM, CHU Bicetre APHP, Paris, France
| | - Fabrice Parker
- Neurosurgery Department, Reference Center Rares Diseases C-MAVEM, CHU Bicetre APHP, Paris, France
| | - Paolo Perrini
- Department of Translational Research and of New Surgical and Medical Technologies, University of Pisa, Pisa, Italy
| | - Maria Antonia Poca
- Neurosurgery and Pediatric Neurosurgery, Vall d'Hebron Hospital Universitari, Neurotrauma and Neurosurgery Research Unit, and Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Juan Sahuquillo
- Neurosurgery and Pediatric Neurosurgery, Vall d'Hebron Hospital Universitari, Neurotrauma and Neurosurgery Research Unit, and Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Marcus Stoodley
- The Australian School of Advanced Medicine, Macquarie University, Macquarie Park, NSW, 2109, Australia
| | | | - Fabio Triulzi
- Neuroradiology Unit, Fondazione IRCCS Ca Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Maria Consuelo Valentini
- Service of Neuroradiology, Diagnostic Imaging Department, AOU Citta' della Salute e della Scienza di Torino, Torino, Italy
| | | | - Laura Valentini
- Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
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Berliner J, Hemley S, Najafi E, Bilston L, Stoodley M, Lam M. Abnormalities in spinal cord ultrastructure in a rat model of post-traumatic syringomyelia. Fluids Barriers CNS 2020; 17:11. [PMID: 32111246 PMCID: PMC7049227 DOI: 10.1186/s12987-020-0171-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 01/18/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Syringomyelia is a serious complication of spinal cord trauma, occurring in approximately 28% of spinal cord injuries. Treatment options are limited and often produce unsatisfactory results. Post-traumatic syringomyelia (PTS) is presumably related to abnormalities of cerebrospinal fluid (CSF) and interstitial fluid hydrodynamics, but the exact mechanisms are unknown. METHODS Transmission electron microscopy (TEM) was used to investigate in detail the interfaces between fluid and tissue in the spinal cords of healthy Sprague-Dawley rats (n = 3) and in a rat model of PTS (n = 3). PTS was induced by computer-controlled impact (75 kDyn) to the spinal cord between C6 and C8, followed by a subarachnoid injection of kaolin to produce focal arachnoiditis. Control animals received a laminectomy only to C6 and C7 vertebrae. Animals were sacrificed 12 weeks post-surgery, and spinal cords were prepared for TEM. Ultra-thin spinal cord sections at the level of the injury were counterstained for structural anatomy. RESULTS Spinal cords from animals with PTS displayed several abnormalities including enlarged perivascular spaces, extracellular edema, cell death and loss of tissue integrity. Additionally, alterations to endothelial tight junctions and an abundance of pinocytotic vesicles, in tissue adjacent to syrinx, suggested perturbations to blood-spinal cord barrier (BSCB) function. CONCLUSIONS These findings support the hypothesis that perivascular spaces are important pathways for CSF flow into and out of the spinal cord, but also suggest that fluid may enter the cord through vesicular transport and an altered BSCB.
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Affiliation(s)
- Joel Berliner
- Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, Sydney, NSW, 2109, Australia.
| | - Sarah Hemley
- Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, Sydney, NSW, 2109, Australia
| | - Elmira Najafi
- Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, Sydney, NSW, 2109, Australia
| | - Lynne Bilston
- Neuroscience Research Australia, Margarete Ainsworth Building, 139 Barker Street, Randwick, NSW, 2031, Australia.,Prince of Wales Clinical School, Faculty of Medicine, University of New South Wales, Randwick, NSW, 2031, Australia
| | - Marcus Stoodley
- Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, Sydney, NSW, 2109, Australia
| | - Magdalena Lam
- Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, Sydney, NSW, 2109, Australia
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Sliow A, Ma Z, Gargiulo G, Mahns D, Mawad D, Breen P, Stoodley M, Houang J, Kuchel R, Tettamanzi GC, Tilley RD, Frost SJ, Morley J, Longo L, Lauto A. Stimulation and Repair of Peripheral Nerves Using Bioadhesive Graft-Antenna. Adv Sci (Weinh) 2019; 6:1801212. [PMID: 31179205 PMCID: PMC6548953 DOI: 10.1002/advs.201801212] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 03/05/2019] [Indexed: 06/09/2023]
Abstract
An original wireless stimulator for peripheral nerves based on a metal loop (diameter ≈1 mm) that is powered by a transcranial magnetic stimulator (TMS) and does not require circuitry components is reported. The loop can be integrated in a chitosan scaffold that functions as a graft when applied onto transected nerves (graft-antenna). The graft-antenna is bonded to rat sciatic nerves by a laser without sutures; it does not migrate after implantation and is able to trigger steady compound muscle action potentials for 12 weeks (CMAP ≈1.3 mV). Eight weeks postoperatively, axon regeneration is facilitated in transected nerves that are repaired with the graft-antenna and stimulated by the TMS for 1 h per week. The graft-antenna is an innovative and minimally-invasive device that functions concurrently as a wireless stimulator and adhesive scaffold for nerve repair.
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Affiliation(s)
- Ashour Sliow
- School of Science and HealthWestern Sydney UniversityLocked Bag 1797PenrithNSW2751Australia
| | - Zhi Ma
- School of MedicineWestern Sydney UniversityPenrithNSW2751Australia
| | - Gaetano Gargiulo
- Biomedical Engineering & Neuroscience Research GroupMARCS InstituteWestern Sydney UniversityPenrithNSW2751Australia
| | - David Mahns
- School of MedicineWestern Sydney UniversityPenrithNSW2751Australia
| | - Damia Mawad
- School of Materials Science and EngineeringUniversity of New South WalesKensingtonNSW2052Australia
| | - Paul Breen
- Biomedical Engineering & Neuroscience Research GroupMARCS InstituteWestern Sydney UniversityPenrithNSW2751Australia
| | - Marcus Stoodley
- The Australian School of Advanced MedicineMacquarie UniversityNorth RydeNSW2109Australia
| | - Jessica Houang
- School of Aerospace, Mechanical and Mechatronic EngineeringUniversity of SydneySydneyNSW2006Australia
| | - Rhiannon Kuchel
- Mark Wainwright Analytical CentreUniversity of New South WalesKensingtonNSW2052Australia
| | - Giuseppe C. Tettamanzi
- School of Physical Sciences and Institute for Photonics and Advanced SensingUniversity of AdelaideAdelaideSA5005Australia
| | - Richard D. Tilley
- Mark Wainwright Analytical CentreUniversity of New South WalesKensingtonNSW2052Australia
| | - Samuel J. Frost
- School of Science and HealthWestern Sydney UniversityLocked Bag 1797PenrithNSW2751Australia
| | - John Morley
- School of MedicineWestern Sydney UniversityPenrithNSW2751Australia
| | - Leonardo Longo
- Faculty of Human SciencesUniversity of the Republic of San MarinoContrada Omerelli47890Republic of San Marino
| | - Antonio Lauto
- School of Science and HealthWestern Sydney UniversityLocked Bag 1797PenrithNSW2751Australia
- School of MedicineWestern Sydney UniversityPenrithNSW2751Australia
- Biomedical Engineering & Neuroscience Research GroupMARCS InstituteWestern Sydney UniversityPenrithNSW2751Australia
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Stoodley M, Rogers J, Gunawardena M, Morgan M. 008 Revascularisation surgery for non-moyamoya symptomatic intracranial stenosis and occlusion. J Neurol Neurosurg Psychiatry 2018. [DOI: 10.1136/jnnp-2018-anzan.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
IntroductionPrevious trials rejected a role of extracranial-to-intracranial bypass surgery for managing symptomatic atheromatous disease. However, haemodynamic insufficiency may still be a rationale for surgery, provided it can be performed with low morbidity and that patency is robust.MethodsConsecutive patients undergoing bypass surgery for non-moyamoya symptomatic intracranial arterial stenosis and occlusion were retrospectively identified. The clinical course and surgical outcomes of the cohort were evaluated at six-weeks, six-months, and annually thereafter.ResultsBetween 1992 and 2017, 112 patients underwent 127 bypasses. The angiographic abnormality was arterial occlusion in 80% and stenosis in 20%. Procedures were to prevent future stroke (76%) and stroke reversal (24%), with revascularisation using an arterial pedicle graft in 80% and venous interposition graft (VIG) in 20%. A poor outcome (bypass occlusion, new stroke, new neurological deficit, or worsening neurologic deficit) occurred in 8.9% of patients. The risk of poor outcome was significantly lower with arterial pedicle grafts (Odds ratio=0.15), bypass for prophylaxis against future stroke (Odds ratio=0.11), or anterior circulation bypass (Odds ratio=0.17). Over the first eight years following surgery there were no poor outcomes in the 66 cases exhibiting all three of these characteristics.ConclusionProphylactic arterial pedicle bypass surgery for anterior circulation ischemia is associated with high graft patency and low stroke and surgical complication rates. Higher risks are associated with acute procedures, typically for posterior circulation pathology and requiring VIGs. A carefully selected subset of individuals with haemodynamic insufficiency and ischaemic symptoms are likely to benefit from cerebral revascularisation surgery.
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Stoodley M, Gauden A, Lee V, Subramanian S, Moutrie V, Zhao Z, McRobb L. 094 Vascular targeting of phosphatidylserine causing thrombotic occlusion in an arteriovenous malformation animal model. J Neurol Neurosurg Psychiatry 2018. [DOI: 10.1136/jnnp-2018-anzan.93] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
IntroductionOne third of brain arteriovenous malformations (AVMs) are untreatable with current methods. Previous work has identified phosphatidylserine externalised in the endothelial plasma membrane after treatment with radiosurgery as a potential target for biological pro-thrombotic therapy. We hypothesise that treatment of AVMs with Gamma knife radiosurgery (GKS) and a vascular targeting agent with a thrombotic compound will cause localised thrombosis within the AVM vessels.MethodsA rat animal model was used by performing an end-to-side anastomosis of the external jugular vein (EJV) to the common carotid artery. The model AVM was treated with radiosurgery (20 Gy) using a Leksell Gamma Knife. At 3 weeks following GKS a dose of a conjugate of annexin V and thrombin was administered intravenously. Groups injected with saline or thrombin alone were used as controls. At 4 weeks, an angiogram was performed with tissue harvested for histology.ResultsThere was angiographic evidence of AVM occlusion in 69% of conjugate-treated animals and none of the control animals (p=0.002). AVM occlusion occurred in 63% of the GKS group treated with conjugate (p=0.03), and in 75% of the sham-GKS conjugate treated group (p=0.009). Histological evidence of thrombus was present within the EJV and nidus of 62.5% of animals in the GKS with conjugate group and <25% of the control groups (p=0.026).ConclusionThis study demonstrates that targeting of PS with an annexin V-thrombin conjugate is effective in causing thrombotic occlusion in a model AVM. These results are the first of their kind and indicate that ligand vascular targeting with radiation sensitisation may become a potential future treatment in brain AVMs.
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Yeo J, Cheng S, Hemley S, Lee BB, Stoodley M, Bilston L. Characteristics of CSF Velocity-Time Profile in Posttraumatic Syringomyelia. AJNR Am J Neuroradiol 2017; 38:1839-1844. [PMID: 28729294 DOI: 10.3174/ajnr.a5304] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 04/24/2017] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The development of syringomyelia has been associated with changes in CSF flow dynamics in the spinal subarachnoid space. However, differences in CSF flow velocity between patients with posttraumatic syringomyelia and healthy participants remains unclear. The aim of this work was to define differences in CSF flow above and below a syrinx in participants with posttraumatic syringomyelia and compare the CSF flow with that in healthy controls. MATERIALS AND METHODS Six participants with posttraumatic syringomyelia were recruited for this study. Phase-contrast MR imaging was used to measure CSF flow velocity at the base of the skull and above and below the syrinx. Velocity magnitudes and temporal features of the CSF velocity profile were compared with those in healthy controls. RESULTS CSF flow velocity in the spinal subarachnoid space of participants with syringomyelia was similar at different locations despite differences in syrinx size and locations. Peak cranial and caudal velocities above and below the syrinx were not significantly different (peak cranial velocity, P = .9; peak caudal velocity, P = 1.0), but the peak velocities were significantly lower (P < .001, P = .007) in the participants with syringomyelia compared with matched controls. Most notably, the duration of caudal flow was significantly shorter (P = .003) in the participants with syringomyelia. CONCLUSIONS CSF flow within the posttraumatic syringomyelia group was relatively uniform along the spinal canal, but there are differences in the timing of CSF flow compared with that in matched healthy controls. This finding supports the hypothesis that syrinx development may be associated with temporal changes in spinal CSF flow.
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Affiliation(s)
- J Yeo
- From Neuroscience Research Australia (J.Y., B.B.L., L.B.), Randwick, New South Wales, Australia
| | - S Cheng
- Department of Engineering (S.C.), Faculty of Science and Engineering
| | - S Hemley
- Australian School of Advance Medicine (S.H., M.S.), Macquarie University, Sydney, New South Wales, Australia
| | - B B Lee
- From Neuroscience Research Australia (J.Y., B.B.L., L.B.), Randwick, New South Wales, Australia
- Prince of Wales Hospital (B.B.L.), Sydney, New South Wales, Australia
- Prince of Wales Clinical School (B.B.L., L.B.), University of New South Wales, Kensington, New South Wales, Australia
| | - M Stoodley
- Australian School of Advance Medicine (S.H., M.S.), Macquarie University, Sydney, New South Wales, Australia
| | - L Bilston
- From Neuroscience Research Australia (J.Y., B.B.L., L.B.), Randwick, New South Wales, Australia
- Prince of Wales Clinical School (B.B.L., L.B.), University of New South Wales, Kensington, New South Wales, Australia
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Chen B, Zhao Z, Lee V, Reddy R, Stoodley M. Radiation-induced expression of platelet endothelial cell adhesion molecule-1 in cerebral endothelial cells. INT J RADIAT RES 2016. [DOI: 10.18869/acadpub.ijrr.14.3.181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Arteriovenous malformations (AVMs) are congenital lesions that cause brain haemorrhage in children and young adults. Current treatment modalities include surgery, radiosurgery and embolization. These treatments are generally effective only for small AVMs. Over one third of AVMs cannot be treated safely and effectively with existing options. Several animal models have been developed with the aims of understanding AVM pathophysiology and improving treatment. No animal model perfectly mimics a human AVM. Each model has limitations and advantages. Models contribute to the understanding of AVMs and hopefully to the development of improved therapies. This paper reviews animal models of AVMs and their advantages and disadvantages.
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Affiliation(s)
- Jude Amal Raj
- The Australian School of Advanced Medicine, Macquarie University, NSW 2109, Australia.
| | - Marcus Stoodley
- The Australian School of Advanced Medicine, Macquarie University, NSW 2109, Australia.
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Kashba SR, Patel NJ, Grace M, Lee VS, Raoufi-Rad N, Raj JVA, Duong TTH, Stoodley M. Angiographic, hemodynamic, and histological changes in an animal model of brain arteriovenous malformations treated with Gamma Knife radiosurgery. J Neurosurg 2015; 123:954-60. [PMID: 25884263 DOI: 10.3171/2014.10.jns1435] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Brain arteriovenous malformations (AVMs) are a major cause of stroke. Many AVMs are effectively obliterated by stereotactic radiosurgery, but such treatment for lesions larger than 3 cm is not as effective. Understanding the responses to radiosurgery may lead to new biological enhancements to this treatment modality. The aim of the present study was to investigate the hemodynamic, morphological, and histological effects of Gamma Knife surgery (GKS) in an animal model of brain AVM. METHODS An arteriovenous fistula was created by anastomosing the left external jugular vein to the side of the common carotid artery in 64 male Sprague-Dawley rats (weight 345 ± 8.8 g). Six weeks after AVM creation, 32 rats were treated with a single dose of GKS (20 Gy); 32 animals received sham radiation. Eight irradiated and 8 control animals were studied at each specified time point (1, 3, 6, and 12 weeks) for hemodynamic, morphological, and histological characterization. RESULTS Two AVMs showed partial angiographic obliteration at 6 weeks. Angiography revealed complete obliteration in 3 irradiated rats at 12 weeks. Blood flow in the ipsilateral proximal carotid artery (p < 0.001) and arterialized jugular vein (p < 0.05) was significantly lower in the irradiated group than in the control group. The arterialized vein's external diameter was significantly smaller in GKS-treated animals at 6 (p < 0.05) and 12 (p < 0.001) weeks. Histological changes included subendothelial cellular proliferation and luminal narrowing in GKS-treated animals. Neither luminal obliteration nor thrombus formation was identified at any of the time points in either irradiated or nonirradiated animals. CONCLUSIONS GKS produced morphological, angiographic, and histological changes in the model of AVM as early as 6 weeks after treatment. These results support the use of this model for studying methods to enhance radiation response in AVMs.
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Affiliation(s)
- Saleh R Kashba
- Australian School of Advanced Medicine, Macquarie University; and
| | - Nirav J Patel
- Australian School of Advanced Medicine, Macquarie University; and
| | - Michael Grace
- Genesis Cancer Care, Macquarie University Hospital, Sydney, New South Wales, Australia
| | - Vivienne S Lee
- Australian School of Advanced Medicine, Macquarie University; and
| | | | - Jude V Amal Raj
- Australian School of Advanced Medicine, Macquarie University; and
| | | | - Marcus Stoodley
- Australian School of Advanced Medicine, Macquarie University; and
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Cheng S, Fletcher D, Hemley S, Stoodley M, Bilston L. Corrigendum to “Effects of fluid structure interaction in a three dimensional model of the spinal subarachnoid space” [J. Biomech. 47 (11) (2014) 2826–2830]. J Biomech 2014. [DOI: 10.1016/j.jbiomech.2014.09.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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18
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Zhao Z, Johnson M, Chen B, Grace M, Ukath J, Lee V, Stoodley M. 203 Ionizing radiation induced phosphatidylserine externalization on endothelial cell surface – a potential target for vascular targeting. Eur J Cancer 2014. [DOI: 10.1016/s0959-8049(14)70329-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Cheng S, Fletcher D, Hemley S, Stoodley M, Bilston L. Effects of fluid structure interaction in a three dimensional model of the spinal subarachnoid space. J Biomech 2014; 47:2826-30. [DOI: 10.1016/j.jbiomech.2014.04.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Revised: 02/11/2014] [Accepted: 04/17/2014] [Indexed: 11/24/2022]
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Raoufi-Rad N, Duong H, Stoodley M. Abstract 184: Irradiation Induces Gene Expression Changes In Cultured Murine Brain Endothelial Cells. Stroke 2013. [DOI: 10.1161/str.44.suppl_1.a184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Brain arteriovenous malformations (AVMs) are abnormal connections between arteries and veins and are the leading cause of hemorrhagic stroke in children and young adults. Treatment of large and deep AVMs remains challenging, therefore new and safe treatment methods are required. Our hypothesis is that stereotactic radiosurgery can be used to selectively alter AVM endothelial cell phenotype, allowing targeted molecular therapies that spare normal vessels. This study examined the post-radiation time course of gene expression changes of potential molecular targets. A murine brain endothelial cell culture (bEnd.3) was treated with 25 Gy using a linear accelerator; non-irradiated cells were used as controls. Quantitative real-time PCR was used to measure the relative gene expression at 1, 6, 12, 24, 48, 72, 96, 120, 144, and 168 h after radiation. Genes encoding for intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were found to be significantly up-regulated post irradiation (p<0.0001), with the maximum level of gene expression for ICAM-1 being evident at 144 h (9-fold) and for VCAM-1 at 120 h (23-fold). Additionally, leukocyte-endothelial cell adhesion molecule 2 (E-selectin) and leukocyte-endothelial cell adhesion molecule 3 (P-selectin) showed significantly increased gene expression at 24 h with 1.5-fold (p<0.001) and 2-fold (p<0.0001) increases respectively. These data support the hypothesis that stereotactic radiosurgery can significantly alter endothelial cell phenotype in AVMs, potentially enabling the use of ligand-based molecular targeting therapies such as the stimulation of thrombosis for AVM treatment.
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Lauto A, Stoodley M, Barton M, Morley JW, Mahns DA, Longo L, Mawad D. Fabrication and application of rose bengal-chitosan films in laser tissue repair. J Vis Exp 2012:4158. [PMID: 23117629 DOI: 10.3791/4158] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Photochemical tissue bonding (PTB) is a sutureless technique for tissue repair, which is achieved by applying a solution of rose bengal (RB) between two tissue edges(1,2). These are then irradiated by a laser that is selectively absorbed by the RB. The resulting photochemical reactions supposedly crosslink the collagen fibers in the tissue with minimal heat production(3). In this report, RB has been incorporated in thin chitosan films to fabricate a novel tissue adhesive that is laser-activated. Adhesive films, based on chitosan and containing ~0.1 wt% RB, are fabricated and bonded to calf intestine and rat tibial nerves by a solid state laser (λ=532 nm, Fluence~110 J/cm(2), spot size~0.5 cm). A single-column tensiometer, interfaced with a personal computer, is used to test the bonding strength. The RB-chitosan adhesive bonds firmly to the intestine with a strength of 15 ± 6 kPa, (n=30). The adhesion strength drops to 2 ± 2 kPa (n=30) when the laser is not applied to the adhesive. The anastomosis of tibial nerves can be also completed without the use of sutures. A novel chitosan adhesive has been fabricated that bonds photochemically to tissue and does not require sutures.
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Affiliation(s)
- Antonio Lauto
- Bioelectronics and Neuroscience (BENS) research group, University of Western Sydney, NSW Australia.
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Liu S, Sammons V, Fairhall J, Reddy R, Tu J, Hong Duong T, Stoodley M. Molecular responses of brain endothelial cells to radiation in a mouse model. J Clin Neurosci 2012; 19:1154-8. [DOI: 10.1016/j.jocn.2011.12.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2011] [Accepted: 12/17/2011] [Indexed: 11/30/2022]
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Wong J, Hemley S, Jones N, Cheng S, Bilston L, Stoodley M. Fluid Outflow in a Large-Animal Model of Posttraumatic Syringomyelia. Neurosurgery 2012; 71:474-80; discussion 480. [DOI: 10.1227/neu.0b013e31825927d6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Sia SF, Davidson AS, Assaad NN, Stoodley M, Morgan MK. Comparative Patency Between Intracranial Arterial Pedicle and Vein Bypass Surgery. Neurosurgery 2011; 69:308-14. [DOI: 10.1227/neu.0b013e318214b300] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
BACKGROUND:
Long-term patency of extracranial-to-intracranial (EC-IC) vein bypass is poorly understood.
OBJECTIVE:
We report our experience of patency of arterial pedicle grafts and interposition vein grafts for the purpose of EC-IC bypass.
METHODS:
We analyzed 294 consecutive patients who underwent 178 intracranial arterial pedicle bypass procedures and 152 intracranial vein bypass procedures. Bypass patency was assessed by digital subtraction angiography, computed tomographic angiography, and/or Doppler ultrasound. The modified Rankin Scale (mRS) was assigned for clinical grading at the last follow-up consultation.
RESULTS:
The main indication for arterial pedicle bypass surgery was internal carotid artery occlusion (79 cases); for vein bypass surgery, it was giant aneurysms (61 cases). Procedure-related complications due to surgery occurred in 3 cases (1.7%; 95% CI: 0.4-5.1%) of arterial pedicle bypass surgery and 12 cases (7.9%; 95% CI: 4.5-13.4%) of vein bypass surgery. The patency rate at 6 weeks was 98% (95% CI: 95.0-99.7%) for arterial pedicle bypass and 93% (95% CI: 87.4-96%) for vein bypass, with almost all graft failures occurring within the first week following surgery. Beyond the first week, bypass patency was similar for both groups, with both arterial pedicle grafts and vein bypass grafts that were patent at 1 week having a long-term patency of 99%. There was no statistically significant difference in early, late, and overall patency between the 2 bypass groups.
CONCLUSION:
The surgical complication rate was greater for vein bypass. Both arterial pedicle and vein bypass have good long-term patency.
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Affiliation(s)
- Sheau Fung Sia
- Australian School of Advanced Medicine, Macquarie University, Sydney, Australia
| | | | - Nazih Nabil Assaad
- Australian School of Advanced Medicine, Macquarie University, Sydney, Australia
| | - Marcus Stoodley
- Australian School of Advanced Medicine, Macquarie University, Sydney, Australia
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Stoodley M, Reddy R, Fairhall J, Smee R, Tu J. Vascular Targeting Enhancement of Radiosurgery for AVMs. J Clin Neurosci 2009. [DOI: 10.1016/j.jocn.2009.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Stoodley M. Traumatic aneurysm. J Neurosurg Pediatr 2009; 3:542; author reply 542. [PMID: 19485744 DOI: 10.3171/2009.3.16381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Storer K, Tu J, Karunanayaka A, Smee R, Short R, Thorpe P, Stoodley M. Coadministration of low-dose lipopolysaccharide and soluble tissue factor induces thrombosis after radiosurgery in an animal arteriovenous malformation model. Neurosurgery 2007; 61:604-10; discussion 610-1. [PMID: 17881975 DOI: 10.1227/01.neu.0000290909.32600.a8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Radiosurgery for arteriovenous malformations is limited to small lesions and may take 3 years to produce total occlusion. It has recently been shown that coadministration of low-dose lipopolysaccharide (LPS) and soluble tissue factor (sTF) selectively induces thrombosis in murine tumor models, attributable perhaps to the prothrombotic phenotype of tumor vasculature. Radiosurgery may induce changes in endothelial prothrombotic molecules similar to those found in tumors. This study aimed to determine if a similar strategy could be used to stimulate thrombus formation in an animal arteriovenous malformation model. METHODS Seventeen rats underwent creation of a carotid-to-jugular anastomosis. Animals were intravenously injected with sTF, low-dose LPS, a combination of both, or placebo 24 hours after stereotactic irradiation of the anastomosis. Control animals received both agents after sham irradiation. RESULTS Coadministration of sTF and LPS led to the formation of thrombi in up to 69% of small vessels and 39% of medium-sized vessels within the target region. The irradiated vasculature demonstrated intermediate rates of thrombosis after treatment with either sTF or LPS alone as did vessels within the fistula in the control group. Logistic regression analysis demonstrated significant associations between development of thrombi and treatment with radiation, sTF, or LPS (P < 0.005). There was no evidence of systemic thrombus formation or toxicity in any group. CONCLUSION Treatment with sTF and LPS selectively induces thrombosis of irradiated vessels in a rat model of arteriovenous malformation. Stimulation of thrombosis may improve the efficacy of radiosurgery, increasing the treatable lesion size and reducing latency.
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Affiliation(s)
- Kingsley Storer
- Prince of Wales Medical Research Institute, University of New South Wales, Sydney, Australia
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Lauto A, Stoodley M, Marcel H, Avolio A, Sarris M, McKenzie G, Sampson DD, Foster LJR. In vitro and in vivo tissue repair with laser-activated chitosan adhesive. Lasers Surg Med 2007; 39:19-27. [PMID: 17066480 DOI: 10.1002/lsm.20418] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND AND OBJECTIVES Sutures are currently the gold standard for wound closure but they are still unable to seal tissue and may induce scarring or inflammation. Biocompatible glues, based on polysaccharides such as chitosan, are a possible alternative to conventional wound closure. In this study, the adhesion of laser-activated chitosan films is investigated in vitro and in vivo. In particular we examine the effect of varying the laser power, as well as adding a natural cross-linker (genipin) to the adhesive composition. STUDY DESIGN/MATERIALS AND METHODS Flexible and insoluble strips of chitosan films (surface area approximately 34 mm(2), thickness approximately 20 microm) were bonded to sheep intestine using several laser powers (0, 80, 120, and 160 mW) at 808-nm wavelength. The strength of repaired tissue was tested by a calibrated tensiometer to select the best power. A natural cross-linker (genipin) was also added to the film and the tissue repair strength compared with the strength of plain films. The adhesive was also bonded in vivo to the sciatic nerve of rats and the thermal damage induced by the laser assessed 4 days post-operatively. RESULTS Chitosan adhesives successfully repaired intestine tissue, attaining a maximum repair strength of 14.7+/-4.3 kPa (n = 30) at the laser power of 120 mW. The chitosan-genipin films achieved lower repair strength (9.1+/-2.9 kPa). The laser caused partial demyelination of axons at the site of operation, but the myelinated axons retained a normal morphology proximally and distally. CONCLUSIONS The chitosan adhesive effectively bonded to tissue causing only localized thermal damage in vivo, when the appropriate laser parameters were selected.
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Affiliation(s)
- A Lauto
- Graduate School of Biomedical Engineering, The University of New South Wales, 2052 New South Wales, Sydney, Australia.
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Papalkar D, Francis IC, Stoodley M, Kaines A, Sharma S, Kalapesi FB, Wilcsek GA. Cavernous haemangioma in the orbital apex: stereotactic-guided transcranial cryoextraction. Clin Exp Ophthalmol 2005; 33:421-3. [PMID: 16033364 DOI: 10.1111/j.1442-9071.2005.01042.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A 55-year-old Caucasian woman presented with an orbital cavernous haemangioma superior to the optic nerve in the orbital apex. Preoperative imaging demonstrated a mass involving the superomedial and superolateral quadrants of the posterior orbit. A stereotactic fronto-orbital approach was performed by the neurosurgical team, and cryoextraction of the lesion was accomplished by the ocular plastic surgical team.
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Affiliation(s)
- Daya Papalkar
- Ocular Plastics Unit, Department of Ophthalmology, Prince of Wales Hospital, and The University of New South Wales, Australia
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Yassari R, Sayama T, Jahromi BS, Aihara Y, Stoodley M, Macdonald RL. Angiographic, hemodynamic and histological characterization of an arteriovenous fistula in rats. Acta Neurochir (Wien) 2004; 146:495-504. [PMID: 15118887 DOI: 10.1007/s00701-004-0248-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND Our understanding of the pathogenesis of arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs) has been limited by the lack of adequate animal models. In this study we evaluate the time course of angiographic, hemodynamic and histopathological changes in an arteriovenous fistula in rats as a potential model. METHODS An arteriovenous fistula was created by a side-to-end anastomosis of the common carotid artery (CCA) to the external jugular vein (EJV). The animals underwent angiography of the fistula and were sacrificed 1, 7, 21, 42 or 90 days later. Flow and pressure measurements were performed in the CCA and ipsi- and contralateral EJV and detailed histological examination of whole mount sections of the fistula and cranium were done on fixed sections. Immunohistochemistry for CD31, smooth muscle alpha-actin and Ki-67 were performed. FINDINGS Hemodynamic changes occur immediately after fistula formation creating a stable high flow, low resistant state. This induces a gradual increase in the inner diameter of the EJV and transverse sinus followed by a decrease in size of the transverse sinus. This decrease is associated with increased expression of alpha-actin in the wall of the sinus. The fistula becomes angiographically and histologically stable after 21 days. CONCLUSION This model describes the time course of hemodynamic and histopathological changes after occur after AVF formation. Stabilization after 21 days makes it an attractive model for mechanistic and therapeutic studies of AVFs.
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Affiliation(s)
- R Yassari
- Section of Neurosurgery, Department of Surgery and Pritzker School of Medicine, University of Chicago Medical Center, Chicago, Illinois 60637, USA
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Macdonald RL, Ono S, Johns L, Marton LS, Weir B, Zhang ZD, Yamini B, Komuro T, Ahmed I, Stoodley M. Molecular weight interactions in experimental vasospasm. Acta Neurochir Suppl 2002; 77:115-7. [PMID: 11563267 DOI: 10.1007/978-3-7091-6232-3_25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Affiliation(s)
- R L Macdonald
- Section of Neurosurgery, Department of Surgery, Pritzker School of Medicine, University of Chicago Medical Center, Chicago, Illinois, USA
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Lüders JC, Weihl CC, Lin G, Ghadge G, Stoodley M, Roos RP, Macdonald RL. Adenoviral gene transfer of nitric oxide synthase increases cerebral blood flow in rats. Neurosurgery 2000; 47:1206-14; discussion 1214-5. [PMID: 11063115 DOI: 10.1097/00006123-200011000-00039] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE Depletion of nitric oxide may play a role in the development of vasospasm after aneurysmal subarachnoid hemorrhage. Replenishment of nitric oxide might be a useful treatment for vasospasm. Using rats, we performed intracisternal injections of replication-defective adenovirus containing the endothelial nitric oxide synthase (eNOS) gene and determined the localization of and effect on cerebral blood flow of transgene expression. METHODS Rats underwent baseline measurement of cortical cerebral blood flow using laser Doppler flowmetry. Replication-defective adenovirus containing the Escherichia coli LacZ gene (Ad327beta-Gal, n = 2/time point) or the bovine eNOS gene (AdCD8-NOS, n = 4/time point) or physiological saline solution was injected into the cisterna magna. Cerebral blood flow was measured 1, 2, 4, 7, or 14 days later, and the animals were killed. Expression of beta-galactosidase activity from the LacZ gene was examined by histochemical staining and that of eNOS was examined by polymerase chain reaction assays of messenger ribonucleic acid. Brains were histopathologically examined for inflammation. RESULTS Beta-galactosidase activity was observed throughout the leptomeninges and in some cells in the adventitia of small subarachnoid blood vessels in the Ad327beta-Gal-injected rats. Messenger ribonucleic acid for eNOS was detected in the leptomeninges and brainstem 1 and 2 days after injection of AdCD8-NOS. Rats injected with Ad327beta-Gal or physiological saline solution exhibited decreased cerebral blood flow beginning 2 days after virus injection and lasting up to 14 days after injection. Rats injected with AdCD8-NOS developed significant transient increases in cerebral blood flow 2 days after virus injection, followed by slight decreases in blood flow. There was inflammation in the subarachnoid space of all animals; the inflammation was qualitatively worse in animals injected with Ad327beta-Gal, compared with rats injected with AdCD8-NOS or saline solution. CONCLUSION Intracisternal injection of replication-defective adenovirus containing the eNOS gene can transiently increase cerebral blood flow.
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Affiliation(s)
- J C Lüders
- Section of Neurosurgery, Pritzker School of Medicine, University of Chicago Medical Center, Illinois 60637, USA
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Abstract
BACKGROUND The purpose of this study was to investigate the effects of blood pressure, temperature, and anesthetic agents on outcome in patients undergoing craniotomy for cerebral aneurysms. METHODS All ruptured and unruptured intracranial aneurysms operated on from 1992 to 1998 were reviewed retrospectively. The data included 297 aneurysms (190 ruptured and 107 unruptured). Data were collected on variables known to influence outcome after aneurysmal subarachnoid hemorrhage as well as on intraoperative factors that might influence outcome (intraoperative blood pressure, temperature, temporary clipping, anesthetic agents). Outcome was assessed at discharge using the Glasgow Outcome Scale. RESULTS In univariate analysis of patients with ruptured aneurysms, younger age, better clinical grade, lower Fisher grade, lower intraoperative blood pressure (maximum systolic and mean blood pressure), smaller decrease in intraoperative compared to preoperative systolic blood pressure, shorter duration of surgery, and use of propofol, pancuronium, or N(2)O were associated with significantly better outcome. In patients with unruptured aneurysms, increased intraoperative minimum diastolic and mean blood pressure, a decrease in the difference between multiple measures of preoperative and intraoperative blood pressure, and a shorter duration of surgery were associated with significantly better outcome. Intraoperative temperature did not affect outcome in either group. In multivariate analysis of patients with ruptured aneurysms, younger age, better clinical grade, lower maximum systolic intraoperative blood pressure, shorter duration of surgery, and use of propofol were independently associated with better outcome. CONCLUSIONS Multivariate analysis of intraoperative factors affecting outcome in patients undergoing craniotomy for ruptured aneurysms shows that decreased intraoperative blood pressure and use of propofol are associated with improved outcome. Univariate analysis suggests that decreasing the magnitude of drop in blood pressure intraoperatively from preoperative values in patients with ruptured or unruptured aneurysms is associated with better outcome. Intraoperative hypothermia did not affect outcome.
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Affiliation(s)
- M Foroohar
- Section of Neurosurgery, Department of Surgery, University of Chicago Medical Center and Pritzker School of Medicine, Chicago, Illinois 60637, USA
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Stoodley M, MacDonald RL, Weir B, Marton LS, Johns L, Du Zhang Z, Kowalczuk A. Subarachnoid hemorrhage as a cause of an adaptive response in cerebral arteries. J Neurosurg 2000; 93:463-70. [PMID: 10969945 DOI: 10.3171/jns.2000.93.3.0463] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT It is not known whether the factors responsible for vasospasm after subarachnoid hemorrhage (SAH) cause the cerebral arteries to be narrowed independent of the subarachnoid blood clot or whether the continued presence of clot is required for the entire time of vasospasm. The authors undertook the present study to investigate this issue. METHODS To distinguish between these possibilities, bilateral SAH was induced in monkeys. The diameters of the monkeys' cerebral arteries were measured on angiograms obtained on Days 0 (the day of SAH), 1, 3, 5, 7, and 9. The subarachnoid blood clot was removed surgically on Day 1, 3, or 5 or, in control animals, was not removed until the animals were killed on Day 7 or 9. The concentrations of hemoglobins and adenosine triphosphate (ATP), substances believed to cause vasospasm, were measured in the removed clots and the contractile activity of the clots was measured in monkey basilar arteries in vitro. If the clot was removed 1 or 3 days after placement, vasospasm was significantly diminished 4 days after clot removal. Clot removal on Day 5 had no marked effect on vasospasm. There was a significant decrease over time in hemoglobin and ATP concentrations and in the contractile activity of the clots, although substantial hemoglobin and contractile activity was still present on Day 7. CONCLUSIONS The authors infer from these results that vasospasm requires the presence of subarachnoid blood for at least 3 days, whereas by Day 5 vasospasm is less dependent on subarachnoid blood clot. Because the clot still contains substantial amounts of hemoglobin and contractile activity after 5 days, there may be an adaptive response in the cerebral arteries that allows them to relax in the presence of the stimulus that earlier caused contraction.
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Affiliation(s)
- M Stoodley
- Department of Surgery, Pritzker School of Medicine, University of Chicago Medical Center, Illinois, USA
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Stoodley M, Weir B. Contents of chronic subdural hematoma. Neurosurg Clin N Am 2000; 11:425-34. [PMID: 10918011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Analysis of chronic subdural hematoma membranes and contents has revealed a complex process of blood breakdown forming a milieu that stimulates neovascularization and repeated hemorrhage.
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Affiliation(s)
- M Stoodley
- Institute of Neurological Science, Prince of Wales Hospital, University of New South Wales, Sydney, Australia
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Stoodley M, Weihl CC, Zhang ZD, Lin G, Johns LM, Kowalczuk A, Ghadge G, Roos RP, Macdonald RL. Effect of adenovirus-mediated nitric oxide synthase gene transfer on vasospasm after experimental subarachnoid hemorrhage. Neurosurgery 2000; 46:1193-202; discussion 1202-3. [PMID: 10807252 DOI: 10.1097/00006123-200005000-00034] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE Evidence indicates that vasospasm after subarachnoid hemorrhage (SAH) is caused in part by a decrease in the vasodilator nitric oxide (NO), which is produced mainly in endothelial cells. This study tested whether intracisternal injection of adenovirus-expressing endothelial NO synthase (eNOS) would decrease vasospasm in dogs. METHODS In 12 dogs, baseline cerebral angiography was performed, and then SAH was produced by two injections of blood into the cisterna magna. The dogs were randomized (n = 6/group) to intracisternal injection of adenovirus-expressing lacZ (Ad327beta-Gal) or eNOS (AdCD8-NOS), administered immediately after the first blood injection. Angiography was repeated on Day 7, and then L-arginine (50 mg) was administered intracisternally, and angiography was repeated. Cerebrospinal fluid aspirated from the cisterna magna on Days 2 and 7 was analyzed for levels of NO metabolites. The dogs were killed, and their basilar arteries were removed and studied pharmacologically. Four control dogs underwent angiography on Day 0, followed by virus injection (n = 2/group). Angiography was repeated on Day 7, and the control dogs were killed. Transgene expression was detected in tissue removed on Day 7 by histochemical staining for lacZ, by polymerase chain reaction for messenger ribonucleic acid for eNOS, and by measurement of NO metabolites in cerebrospinal fluid. RESULTS Angiography showed significant vasospasm in each group (Ad327beta-Gal, -54 +/- 7% reduction in basilar artery diameter; AdCD8-NOS, -53 +/- 7%), with no significant difference between groups. Injection of L-arginine caused an insignificant increase in arterial diameter in each group. In dogs without SAH, Ad327beta-Gal caused a reduction in basilar artery diameter (-13 +/- 10%, P = 0.42; paired t test), whereas injection of AdCD8-NOS caused an increase in diameter (14 +/- 16%, P = 0.77; paired t test). Histological examination and beta-galactosidase staining of dogs given injections of Ad327beta-Gal showed staining in inflammatory cells in the subarachnoid space, in the adventitia of the cerebral vessels, and in the liver and lungs. Messenger ribonucleic acid for eNOS was detected in the leptomeninges of dogs given injections of AdCD8-NOS. Under isometric tension, basilar arteries from each group demonstrated similar relaxation to L-arginine, but arteries exposed to eNOS demonstrated significantly greater relaxation to L-arginine plus tetrahydrobiopterin than arteries exposed to lacZ. Cerebrospinal fluid levels of NO and its metabolites were significantly higher in dogs treated with AdCD8-NOS than those treated with Ad327beta-Gal 2 days after SAH. CONCLUSION These results demonstrate that adenovirus vectors can be used to transfer genes to cells in the subarachnoid space of dogs. Enough NO can be produced in the absence of SAH to dilate the basilar artery. After SAH, however, NO plus a cofactor can dilate arteries in vitro, but not enough NO is generated in the subarachnoid space to prevent vasospasm, perhaps owing to the scavenging of NO by hemoglobin.
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Affiliation(s)
- M Stoodley
- Section of Neurosurgery, Pritzker School of Medicine, University of Chicago, Illinois 60637, USA
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Abstract
Cerebral vasospasm is a gradual onset and prolonged constriction of the cerebral arteries in the subarachnoid space after subarachnoid hemorrhage. The principal cause is the surrounding blood clot. The significance of vasospasm is that flow through the constricted arteries may be reduced sufficiently to cause cerebral infarction. Subarachnoid blood clot is sufficient to cause vasospasm; it does not require additional arterial injury, intracranial hypertension or brain infarction, although these elements are often coexistent. The blood released at the time of aneurysmal rupture into the alien subarachnoid environment is an extraordinarily complex mix of cellular and extracellular elements that evolves as clotting occurs; cells disintegrate; local inflammation, phagocytosis and repair take place; severe constriction alters the metabolism and structure of the arterial wall as well as the balance of vasoconstrictor and dilator substances produced by its endothelium, neurogenic network and perhaps smooth muscle cells.
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Affiliation(s)
- B Weir
- Section of Neurosurgery, Pritzker School of Medicine, University of Chicago, USA
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Abstract
OBJECTIVE To review the principles of and the experimental and clinical results of gene therapy for cerebrovascular disease. METHODS Literature review. RESULTS Vectors for gene transfer into the brain or into the cerebral vasculature include naked plasmid deoxyribonucleic acid, cationic liposomes, and viruses such as adenovirus, retrovirus, adeno-associated virus, and herpes simplex virus. Experiments using these vectors showed that intra- or perivascular application to systemic arteries can lead to transfection and expression of a foreign transgene in the adventitia and the endothelium. Intrathecal administration can lead to transfection and foreign transgene expression in leptomeningeal cells as well as in fibroblasts of blood vessel adventitia. Biological effects demonstrated thus far include increased nitric oxide production by transfection of cerebral arterial adventitia with adenovirus expressing nitric oxide synthase. Adenoviruses carrying foreign genes have been used to decrease neuronal damage in cerebral ischemia and to decrease blood pressure in spontaneously hypertensive rats. Vectors and therapeutic applications for gene therapy are evolving rapidly. CONCLUSION Gene therapy for cerebrovascular disease is likely to have clinical application in the near future and will have a major impact on neurosurgery. Neurosurgeons will need to be aware of the literature in this area.
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Affiliation(s)
- C Weihl
- Department of Neurology, University of Chicago Medical Center and Pritzker School of Medicine, Illinois 60037, USA
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Abstract
The purpose of this manuscript is to briefly review the pathophysiology of cerebral ischemia. Ischemic thresholds are well-defined in lower animals. The concept of the ischemic penumbra may include regions of brain around deeper regions of ischemia but has also been defined in terms of brain salvageable by reperfusion or by pharmacological therapies. The principal pathophysiological processes in cerebral ischemia are energy failure, loss of cell ion homeostasis, acidosis, increased intracellular calcium, excitotoxicity, and free radical-mediated toxicity. The underlying biochemical processes are similar regardless of the amount of brain that is made ischemic or the duration of ischemia. The relative contributions of each process are believed to vary significantly especially in relation to the level of cerebral blood flow. Neurons may die by necrosis or apoptosis. In the core of an infarct where blood flow is very low, the predominant process is energy failure and rapid necrotic cell death. Reperfusion of ischemic tissue produces an influx of inflammatory cells and of oxygen that can cause increases in oxygen-derived free radicals. Free radicals are also important in prolonged ischemia. There is interest in changes in gene expression after ischemia. Induction of heat shock proteins suggests that gene expression changes may protect neurons from death. Changes in gene expression also may initiate apoptosis or other detrimental processes. Although advances have been made, there are still no proven pharmacological therapies to rescue ischemic human neurons. Such therapies do appear to be on the horizon.
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Affiliation(s)
- R L Macdonald
- Section of Neurosurgery, University of Chicago Medical Center, Illinois, USA
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