gms | German Medical Science

59th Annual Meeting of the German Society of Neurosurgery (DGNC)
3rd Joint Meeting with the Italian Neurosurgical Society (SINch)

German Society of Neurosurgery (DGNC)

1 - 4 June 2008, Würzburg

Morphometrical analysis and operative microanatomy of the lateral suboccipital approach to the cerebellopontine angle

Morphometrische Analyse und operative Mikroanatomie des lateralen suboccipitalen Zugangs zum Kleinhirnbrückenwinkel

Meeting Abstract

  • corresponding author P.A. Winkler - Labor für Neurochirurgische Mikroanatomie, Neurochirurgische Klinik, Klinikum Großhadern, LMU München
  • N. Piotrowska - Labor für Neurochirurgische Mikroanatomie, Neurochirurgische Klinik, Klinikum Großhadern, LMU München
  • E. Wenger - Kommission für Wissenschaftliche Visualisierung, Österreichische Akademie der Wissenschaften, Wien
  • A. Ardeshiri - Labor für Neurochirurgische Mikroanatomie, Neurochirurgische Klinik, Klinikum Großhadern, LMU München
  • J.-C. Tonn - Labor für Neurochirurgische Mikroanatomie, Neurochirurgische Klinik, Klinikum Großhadern, LMU München

Deutsche Gesellschaft für Neurochirurgie. Società Italiana di Neurochirurgia. 59. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3. Joint Meeting mit der Italienischen Gesellschaft für Neurochirurgie (SINch). Würzburg, 01.-04.06.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. DocP 109

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dgnc2008/08dgnc377.shtml

Published: May 30, 2008

© 2008 Winkler et al.
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Outline

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Objective: The lateral suboccipital approach represents the standard approach to lesions in the cerebellopontine angle, mainly acoustic neurinomas and meningeomas. The operative route starts with retrosigmoidal craniotomy, for which the correctly placed burr hole in the junction of transverse and sigmoid sinus is essential, and proceeds with preparation towards the cranial nerves. Since morphometrical analyses of this approach have not yet been performed, we conducted a detailed morphometrical analysis and correlative microanatomical preparations of this surgical corridor.

Methods: Fifty three magnetization prepared rapid acquisition gradient echo-sequences (MPRAGE) of individual brains without pathological lesions were analysed. We chose sections in the plane of the jugular bulb (the plane of the maximal lateral extention of the cerebellum) and marked landmarks on them (maximal lateral extension points of the cerebellum on the both sides and the midline point in the vermis between them as well as the exit points of the lower cranial nerves at brainstem on the both sides) which describe the surgical corridor. A specially designed software measured relevant distances.

Results: The lateral extension of the cerebellum had a mean distance of 47.42±6.77 mm on the right side and 47.54±6.90 mm on the left side.This distance gives an idea of the degree of retraction required during surgery and of the different types of cerebellar curvature. The distance between the point of the maximal lateral extension of the cerebellum and the entry point of the lower cranial nerves into the brain stem was 38.81±9.31 mm on the right side and 39.73±9.48 mm on the left side.These distances provide information on the length of the operative corridor.

Conclusions: The preoperative assessment of these distances can be helpful for planning the surgical approach. Knowledge of these distances and their variability can be crucial to avoid brain damage during retraction or manipulation in surgery involving the cerebellopontine angle.