Abstract
Objectives The central location and complex neurovascular structures of the posterior cranial
fossa make tumor resection in this region challenging. The traditional surgical approach
is a suboccipital craniotomy using a microscope for visualization. This approach necessitates
a large surgical window and cerebellar retraction, which can result in patient morbidity.
With the advances in endoscopic technology, minimally invasive access to the cerebellopontine
angle can be achieved with minimal manipulation of uninvolved structures, reducing
the complications associated with the suboccipital approach.
Methods An endoscopic and microscopic approach was completed on anatomic specimens. To access
the central structures of the posterior cranial fossa, a retrosigmoidal approach was
undertaken. A keyhole craniotomy was made in the occipital bone posterior to the junction
of the transverse and sigmoid sinuses. The endoscope was advanced and photographs
were obtained for review. The exposure was compared with that obtained with a microscope.
Results The endoscopic retrosigmoidal approach to the posterior cranial fossa provided increased
exposure to the midline structures while minimizing the surgical window. The relevant
anatomy was identified without difficulty.
Conclusion An endoscopic retrosigmoidal approach to the midline structures of the posterior
cranial fossa is anatomically feasible. The morbidity associated with retraction of
the cerebellum could possibly be avoided, improving patient outcomes. Retrosigmoidal
endoscopy provides access to anatomical structures that is not possible using a microscope
in a suboccipital approach. Further understanding of the endoscopic anatomy of the
posterior fossa can allow for advances in cranial base surgery with improved safety
and efficacy.
Keywords
cerebellopontine angle - keyhole approach - endoscopy-assisted microsurgery - endoscopic
retrosigmoidal approach - endoscopy-assisted microsurgery - intracranial tumor
