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1.
Oper Neurosurg (Hagerstown) ; 18(1): 83-91, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31323686

RESUMO

BACKGROUND: A combined drill distance control and virtual drilling image guidance feedback method was developed. OBJECTIVE: To investigate whether first-time usage of the proposed method, during anterior petrosectomy (AP), improves surgical orientation and surgical performance. The accuracy of virtual drilling and the clinical practicability of the method were also investigated. METHODS: In a simulated surgical setting using human cadavers, a trial was conducted with 5 expert skull base surgeons from 3 different hospitals. They performed 10 AP approaches, using either the feedback method or standard image guidance. Damage to critical structures was assessed. Operating time, drill cavity sizes, and proximity of postoperative drill cavities to the cochlea and the acoustic meatus, were measured. Questionnaires were obtained postoperatively. Errors in the virtual drill cavities as compared with actual postoperative cavities were calculated. In a clinical setup, the method was used during AP. RESULTS: Surgeons rated their intraoperative orientation significantly better with the feedback method compared with standard image guidance. During the cadaver trial, the cochlea was harmed on 1 occasion in the control group, while surgeons drilled closer to the cochlea and meatus without injuring them in the group using feedback. Virtual drilling under- and overestimation errors were 2.2 ± 0.2 and -3.0 ± 0.6 mm on average. The method functioned properly during the clinical setup. CONCLUSION: The proposed feedback method improves orientation and surgical performance in an experimental setting. Errors in virtual drilling reflect spatial errors of the image guidance system. The feedback method is clinically practicable during AP.


Assuntos
Neuronavegação/instrumentação , Neuronavegação/métodos , Base do Crânio/cirurgia , Craniotomia/instrumentação , Craniotomia/métodos , Humanos , Processamento de Imagem Assistida por Computador , Cirurgia Assistida por Computador/instrumentação , Cirurgia Assistida por Computador/métodos
2.
World Neurosurg ; 126: e250-e258, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30797931

RESUMO

BACKGROUND: Ultra-high-field magnetic resonance imaging (MRI) of the brain is attractive for image guidance during neurosurgery because of its high tissue contrast and detailed vessel visualization. However, high-field MRI is prone to distortion artifacts, which may compromise image guidance. Here we investigate intra- and extracranial distortions in 7-T MRI scans. METHODS: Five patients with and 5 patients without skin-adhesive fiducials received magnetization-prepared T1-weighted 7-T MRI and standard 3-T MRI scans. The 7- and 3-T images were rigidly coregistered and compared. Intracranial distortions were evaluated qualitatively, whereas shifts at the skin surface and shifts of the center positions of skin-adhesive fiducials were measured quantitatively. Moreover, we present an illustrative case of an ultra-high-field image-guided skull base meningioma resection. RESULTS: We found excellent intracranial correspondence between 3- and 7-T MRI scans. However, the average maximum skin shift was 6.8 ± 2.0 mm in group A and 5.2 ± 0.9 mm in group B. The average maximum difference between the skin-adhesive fiducial positions was 5.6 ± 3.1 mm in group B. In our tumor resection case, the meningioma blood supply could be targeted early thanks to 7-T image guidance, which made subsequent tumor removal straightforward. CONCLUSIONS: There are no visible intracranial distortions in magnetization-prepared T1-weighted 7-T MRI cranial images. However, we found considerable extracranial shifts. These shifts render 7-T images unreliable for patient-to-image registration. We recommend performing patient-to-image registration on a routine (computed tomography scan or 3-T magnetic resonance) image and subsequently fusing the 7-T magnetic resonance image with the routine image on the image guidance machine, until this issue is resolved.


Assuntos
Imageamento por Ressonância Magnética/métodos , Procedimentos Neurocirúrgicos/métodos , Cirurgia Assistida por Computador/métodos , Adesivos , Adulto , Idoso , Idoso de 80 Anos ou mais , Artefatos , Campos Eletromagnéticos , Feminino , Humanos , Masculino , Meningioma/irrigação sanguínea , Meningioma/diagnóstico por imagem , Meningioma/cirurgia , Imagens de Fantasmas , Reprodutibilidade dos Testes , Neoplasias da Base do Crânio/irrigação sanguínea , Neoplasias da Base do Crânio/diagnóstico por imagem , Neoplasias da Base do Crânio/cirurgia
3.
J Neurol Surg B Skull Base ; 79(2): 161-166, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29868321

RESUMO

Introduction Managing internal carotid artery (ICA) injury during extended endoscopic transsphenoidal surgery is an extreme challenge. We aimed to find a possible surgical treatment strategy. Methods We operated seven fresh, perfused cadaver heads with a transsphenoidal endoscopic approach of the ICA using a three-dimensional-high definition (3D-HD) endoscope. We made a paraclival ICA leak, which we tried to manage with clips and microsutures. Results Accurate transsphenoidal clip application on the ICA was impossible with standard aneurysm clips and applier. It was only feasible with a 9 mm slightly bended clip that could be opened from the inside and be applied with a dedicated flexible thin applier. Transsphenoidal suturing of an ICA leak was impossible from the ipsilateral nostril or with standard microinstruments. Suturing was only feasible from the contralateral nostril using flexible microinstruments with a thin 90-mm shaft. This was technically very challenging and involved a steep learning curve. Conclusion Tamponade with muscle or fat and a quick transfer to the angiography suite for endovascular control remains the preferable option in case of an ICA leak during endoscopic transsphenoidal surgery. If tamponade gives insufficient initial control, ICA clipping could be possible with dedicated instruments, with risk of increasing the defect, stenosis, or occlusion of the vessel. Transsphenoidal ICA suturing remains extremely difficult, and laboratory practice seems essential.

4.
World Neurosurg ; 109: e217-e228, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28966150

RESUMO

BACKGROUND: Novel audiovisual feedback methods were developed to improve image guidance during skull base surgery by providing audiovisual warnings when the drill tip enters a protective perimeter set at a distance around anatomic structures ("distance control") and visualizing bone drilling ("virtual drilling"). OBJECTIVE: To benchmark the drill damage risk reduction provided by distance control, to quantify the accuracy of virtual drilling, and to investigate whether the proposed feedback methods are clinically feasible. METHODS: In a simulated surgical scenario using human cadavers, 12 unexperienced users (medical students) drilled 12 mastoidectomies. Users were divided into a control group using standard image guidance and 3 groups using distance control with protective perimeters of 1, 2, or 3 mm. Damage to critical structures (sigmoid sinus, semicircular canals, facial nerve) was assessed. Neurosurgeons performed another 6 mastoidectomy/trans-labyrinthine and retro-labyrinthine approaches. Virtual errors as compared with real postoperative drill cavities were calculated. In a clinical setting, 3 patients received lateral skull base surgery with the proposed feedback methods. RESULTS: Users drilling with distance control protective perimeters of 3 mm did not damage structures, whereas the groups using smaller protective perimeters and the control group injured structures. Virtual drilling maximum cavity underestimations and overestimations were 2.8 ± 0.1 and 3.3 ± 0.4 mm, respectively. Feedback methods functioned properly in the clinical setting. CONCLUSION: Distance control reduced the risks of drill damage proportional to the protective perimeter distance. Errors in virtual drilling reflect spatial errors of the image guidance system. These feedback methods are clinically feasible.


Assuntos
Benchmarking , Retroalimentação Sensorial , Comportamento de Redução do Risco , Base do Crânio/cirurgia , Cirurgia Assistida por Computador/instrumentação , Cirurgia Assistida por Computador/métodos , Interface Usuário-Computador , Adulto , Desenho de Equipamento , Feminino , Humanos , Complicações Intraoperatórias/diagnóstico por imagem , Complicações Intraoperatórias/prevenção & controle , Masculino , Mastoidectomia/instrumentação , Mastoidectomia/métodos , Neurocirurgia/educação , Base do Crânio/diagnóstico por imagem , Estudantes de Medicina , Tomografia Computadorizada por Raios X/instrumentação
5.
Epilepsia ; 54(11): 1855-65, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24032627

RESUMO

Brain functioning is increasingly seen as a complex interplay of dynamic neural systems that rely on the integrity of structural and functional networks. Recent studies that have investigated functional and structural networks in epilepsy have revealed specific disruptions in connectivity and network topology and, consequently, have led to a shift from "focus" to "networks" in modern epilepsy research. Disruptions in these networks may be associated with cognitive and behavioral impairments often seen in patients with chronic epilepsy. In this review, we aim to provide an overview that would introduce the clinical neurologist and epileptologist to this new theoretical paradigm. We focus on the application of a theory, called "network analysis," to characterize resting-state functional and structural networks and discuss current and future clinical applications of network analysis in patients with epilepsy.


Assuntos
Encéfalo/fisiopatologia , Epilepsia/fisiopatologia , Rede Nervosa/fisiopatologia , Animais , Encéfalo/patologia , Mapeamento Encefálico/métodos , Cognição , Humanos , Modelos Neurológicos
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