Minim Invasive Neurosurg 2003; 46(2): 100-105
DOI: 10.1055/s-2003-39345
Original Article
© Georg Thieme Verlag Stuttgart · New York

The Extradural Subtemporal Keyhole Approach to the Sphenocavernous Region: Anatomic Considerations

Y.  Kocaoğullar1 , E.  Avcı2 , D.  Fossett2 , A.  Caputy3
  • 1Department of Neurosurgery, Selçuk University, Konya, Turkey
  • 2Harvey Ammerman Neurosurgical Laboratory Department of Neurosurgery, George Washington University, Washington DC/USA
  • 3Department of Neurosurgery, George Washington University, Washington DC, USA
Further Information

Publication History

Publication Date:
22 May 2003 (online)

Abstract

Fourteen cadaver specimens (28 sides) and twelve dry human skulls (24 sides) were used to study the anatomic relationships between bony, neurovascular and foraminal landmarks in the floor of the middle fossa in preparation for performing the extradural subtemporal keyhole approach to the sphenocavernous region. The interforaminal distance was largest between the foramina rotundum (FR) and ovale (FO) and was smallest between the FO and foramen spinosum (FS). The largest angle between exit foramen was the FR to FO. The greater superficial petrosal nerve (GSPN) was always found to overlie and run parallel to the petrous internal carotid artery, however, its location over the artery and its separation from it by bone was variable. With a subtemporal “keyhole” placed above the posterior zygomatic root (PZR), a 0° endoscope allowed easy visualization of the middle meningeal artery (MMA) and the mandibular nerve (V3) however, a 30° endoscope was more useful for visualizing the maxillary nerve (V2) and the ophthalmic nerve (V2). With a sphenoidotomy performed between V1 and V2, the 30° endoscope was found to be the most useful for visualizing the carotid siphon and the contralateral wall of the sphenoid sinus, while the 70° endoscope was the most useful for visualizing of the floor of the sella and the walls of the sphenoid sinus. Two venous concerns with respect to performing endoscopic approaches to the region were identified: a fibrous layer overlies a heavy venous plexus that encircles the petrous carotid artery, and the foramen Vesalius, which transmits a large emissary vein draining the cavernous sinus, was identified medial to the FO in 30 % of our dissected sides.

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Dr. Y. Kocaogullar

Selçuk Üniversitesi Tıp Fakültesi Hastanesi

Beyin Cerrahisi Anabilimdalı 42080

Konya

Turkey

Phone: +90-332 3232600-1150

Phone: +90-332 3232600-1618

Fax: +90 332 3232643

Email: kyalcin34@hotmail.com