An anatomical study of the foramen of Monro: implications in management of pineal tumors presenting with hydrocephalus.
Acta Neurochir (Wien)
; 161(5): 975-983, 2019 05.
Article
em En
| MEDLINE
| ID: mdl-30953154
ABSTRACT
BACKGROUND:
For pineal tumors presenting with hydrocephalus, simultaneous endoscopic third ventriculostomy (ETV) and tumor biopsy is commonly used as the initial step in management. To analyze the restriction which the foramen of Monro poses to this procedure, one must start with a detailed description of the microsurgical anatomy of the foramen in living subjects. However, the orientation and shape of the foramen of Monro make this description difficult with conventional imaging techniques.METHOD:
Virtual reality technology was applied on MRIs on living subject without hydrocephalus, as well as patients with hydrocephalus, to generate precise anatomical models with sub-millimeter accuracy. The morphometry of the foramen of Monro was studied in each group. In addition, displacement of the margins of the foramen was studied in detail for simultaneous ETV and pineal tumor biopsy through a single burr hole.RESULTS:
In 30 normal subjects, the foramen of Monro had oval-shaped openings averaging 5.23 mm2. The foramen was larger in people above age 55 (p = 0.007) and on the left side compared to the right (p = 0.002). For patients with clinical presentation of hydrocephalus, the average opening was 32.6 mm2. Simulated single burr hole simultaneous ETV and pineal tumor biopsy was performed in 10 specimens. Average displacement of the posterior and anterior margins of the foramen was 5.71 mm and 5.76 mm, respectively. However, maximum displacement reached 9.3 mm posteriorly and 10 mm anteriorly.CONCLUSIONS:
The foramen of Monro is an oval-shaped cylinder that changes in size and orientation in the hydrocephalic patient. If universally applied to all patients regardless of foramen and tumor size, ETV/biopsy can displace structures around the Foramen of Monro up to 1 cm, which can potentially lead to neurological damage. Careful pre-operative assessment is critical to determine if a single burr hole approach is safe.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pinealoma
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Trepanação
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Imageamento por Ressonância Magnética
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Ventriculostomia
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Terceiro Ventrículo
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Modelagem Computacional Específica para o Paciente
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Hidrocefalia
Limite:
Adolescent
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Adult
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Acta Neurochir (Wien)
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Estados Unidos