Meckel's cave.

OBJECTIVE: To review the microsurgical anatomy of Meckel's cave, a detailed knowledge of which is a prerequisite to devising an appropriate surgical strategy and performing successful surgery.

METHODS: The microsurgical anatomy of Meckel's cave was studied under an operating microscope in 15 human cadaver heads (30 sides). To understand the meningeal architecture and the cross-sectional anatomy of Meckel's cave, serial histologic sections were made in an additional adult human cadaver specimen.

RESULTS: Meckel's cave is a natural mouth-shaped aperture connecting with the posterior fossa that is located in the medial portion of the middle cranial fossa. The cave extends forward similar to an open-ended three-fingered glove and provides a channel for the rootlets of the trigeminal nerve; the trigeminal ganglion; and the ophthalmic (cranial nerve V(1)), maxillary (cranial nerve V(2)), and mandibular (cranial nerve V(3)) divisions until they reach their respective foramina. The average height of this oval mouth was found to be 4.2 mm (range 3-5 mm) and the average width was 7.6 mm (range 6-8 mm). The mouth of Meckel's cave was located 12 mm (range 10-15 mm) superior and medial to the internal acoustic meatus and 6.5 mm (range 5-8 mm) superior and medial to the dural point of entrance of the nervus abducens and 20 mm (range 18-23 mm) medial to the arcuate eminence.

CONCLUSIONS: Detailed and sound knowledge of the microsurgical anatomy of Meckel's cave, which borders on surgically important structures, such as the internal carotid artery and cavernous sinus, is essential to performing precise microneurosurgery in this region. This study describes the complex anatomy of Meckel's cave and surrounding structures to provide the knowledge needed to devise a more complete surgical strategy and establish accurate orientation during the surgical procedure.