Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Middle Fossa Approaches and Anterior Petrosectomy, Surgical Principles, and Illustrative Cases

Abstract

Introduction The middle fossa (MF) approaches encompass a group of versatile surgical accesses to pathologies in the MF, internal auditory canal (IAC), and superomedial aspect of the posterior fossa. Although many descriptions of the MF approaches have been published, a practical surgical guide that allows an easy understanding for Skull Base trainees is needed.

Methods Three formalin-fixed, colored-injected specimens were dissected under microscopic magnification (six sides). A MF craniotomy followed by IAC drilling was performed on three sides, and anterior petrosectomy (AP) was performed in the remaining three sides. The anatomical dissection was documented in stepwise three-dimensional photographic images. Following dissection, representative case applications were reviewed.

Results The MF approach provides direct access to the MF structures and IAC. The AP provides excellent access to the superomedial aspect of the posterior fossa. Key common steps include: positioning and skin incision; scalp and muscle flaps; burr holes; craniotomy flap elevation; dural dissection along the petrous ridge; division of the middle meningeal artery; and exposure of the greater superficial petrosal nerve, tegmen tympani, and V3. Then, to approach the IAC: superior IAC drilling, and longitudinal dura opening. The area drilled in the AP approach forms a pentagon limited by the petrous internal carotid artery, cochlea, IAC, petrous ridge, and lateral border of V3.

Conclusion The MF approaches are challenging. Operatively oriented skull base dissections provide a crucial foundation for learning these techniques. We describe comprehensive step-by-step approaches intended to develop familiarity in the cadaver laboratory and facilitate understanding of their potential for skull base disorders. Basic surgical principles are described to help in the operating room as well as illustrative cases.

Keywords

middle fossa - anterior petrosectomy - skull base - internal auditory canal - vestibular schwannoma - tegmen defect

• References

• 1 Parry RH. A case of tinnitus and vertigo treated by division of the auditory nerve. 1904. J Laryngol Otol 1991; 105 (12) 1099-1100
• 2 Fisch U. [Microsurgery of the temporal bone (author's transl)]. HNO 1977; 25 (06) 193-197
• 3 Rhoton Jr AL. The temporal bone and transtemporal approaches. Neurosurgery 2000; 47 (3, Suppl): S211-S265
• 4 Lambert PR. House: “surgical exposure of the internal auditory canal and its contents through the middle cranial fossa.” (Laryngoscope. 1961;71:1363-1385). Laryngoscope 1996; 106 (10) 1195-1198
• 5 Kawase T, Toya S, Shiobara R, Mine T. Transpetrosal approach for aneurysms of the lower basilar artery. J Neurosurg 1985; 63 (06) 857-861
• 6 House WF, Gardner G, Hughes RL. Middle cranial fossa approach to acoustic tumor surgery. Arch Otolaryngol 1968; 88 (06) 631-641
• 7 Dones F, Kournoutas I, Vigo V. et al. A combined extradural-intradural technique for an en bloc anterior petrosectomy: a cadaveric feasibility study. World Neurosurg 2019:S1878-8750(18)32912-7
• 8 Steiger HJ, Hänggi D, Stummer W, Winkler PA. Custom-tailored transdural anterior transpetrosal approach to ventral pons and retroclival regions. J Neurosurg 2006; 104 (01) 38-46
• 9 Leonel L, Carlstrom L, Graffeo C. et al. Foundations of advanced neuroanatomy: technical guidelines for specimen preparation, dissection, and 3D-photodocumentation in a surgical anatomy laboratory. J Neurol Surg B Skull Base 2019
• 10 Peris-Celda M, Perry A, Carlstrom LP, Graffeo CS, Driscoll CLW, Link MJ. Key anatomical landmarks for middle fossa surgery: a surgical anatomy study. J Neurosurg 2018;
• 11 El-Khouly H, Fernandez-Miranda J, Rhoton Jr AL. Blood supply of the facial nerve in the middle fossa: the petrosal artery. Neurosurgery 2008; 62 (05, Suppl 2): discussion ONS303–ONS304 ONS297-ONS303
• 12 Fisch U. Infratemporal fossa approach to tumours of the temporal bone and base of the skull. J Laryngol Otol 1978; 92 (11) 949-967
• 13 Garcia-Ibanez E, Garcia-Ibanez JL. Middle fossa vestibular neurectomy: a report of 373 cases. Otolaryngol Head Neck Surg 1980; 88: 486-490
• 14 Altieri R, Sameshima T, Pacca P. et al. Detailed anatomy knowledge: first step to approach petroclival meningiomas through the petrous apex. Anatomy lab experience and surgical series. Neurosurg Rev 2017; 40 (02) 231-239
• 15 Borghei-Razavi H, Tomio R, Fereshtehnejad SM. et al. Pathological location of cranial nerves in petroclival lesions: how to avoid their injury during anterior Petrosal approach. J Neurol Surg B Skull Base 2016; 77 (01) 6-13
• 16 Tanriover N, Sanus GZ, Ulu MO. et al. Middle fossa approach: microsurgical anatomy and surgical technique from the neurosurgical perspective. Surg Neurol 2009; 71 (05) 586-596 , discussion 596
• 17 Angeli S. Middle fossa approach: indications, technique, and results. Otolaryngol Clin North Am 2012; 45 (02) 417-438 , ix
• 18 MacDonald JD, Antonelli P, Day AL. The anterior subtemporal, medial transpetrosal approach to the upper basilar artery and ponto-mesencephalic junction. Neurosurgery 1998; 43 (01) 84-89
• 19 Falcioni M, Fois P, Taibah A, Sanna M. Facial nerve function after vestibular schwannoma surgery. J Neurosurg 2011; 115 (04) 820-826
• 20 Khrais T, Romano G, Sanna M. Nerve origin of vestibular schwannoma: a prospective study. J Laryngol Otol 2008; 122 (02) 128-131
• 21 Jackler RK, Pitts LH. Selection of surgical approach to acoustic neuroma. 1992. Neurosurg Clin N Am 2008; 19 (02) 217-238 , vi
• 22 Graffeo C, Peris-Celda M, Perry A, Carlstrom L, Driscoll C, Link M. Anatomical step-by-step dissection of complex skull base approaches for trainees: surgical anatomy of the retrosigmoid approach. J Neurol Surg B Skull Base 2020;
• 23 Miller CG, van Loveren HR, Keller JT, Pensak M, el-Kalliny M, Tew Jr JM. Transpetrosal approach: surgical anatomy and technique. Neurosurgery 1993; 33 (03) 461-469 , discussion 469
• 24 Aziz KM, Tew Jr JM, Chicoine MR, Chicoine MR. van Loveren HR. The Kawase approach to retrosellar and upper clival basilar aneurysms. Neurosurgery 1999; 44 (06) 1225-1234 , discussion 1234–1236
• 25 Diaz Day J. The middle fossa approach and extended middle fossa approach: technique and operative nuances. Neurosurgery 2012; 70 (02) , Suppl Operative ): 192-201
• 26 Sekhar LN, Kalia KK, Yonas H, Wright DC, Ching H. Cranial base approaches to intracranial aneurysms in the subarachnoid space. Neurosurgery 1994; 35 (03) 472-481 , discussion 481–483
• 27 Chang SW, Wu A, Gore P. et al. Quantitative comparison of Kawase's approach versus the retrosigmoid approach: implications for tumors involving both middle and posterior fossae. Neurosurgery 2009; 64 (3, Suppl): discussion ons51–ons52 ons44-ons51
• 28 Graffeo CS, Peris-Celda M, Perry A, Carlstrom LP, Driscoll CLW, Link MJ. Anatomical step-by-step dissection of complex skull base approaches for trainees: surgical anatomy of the posterior petrosal approach. J Neurol Surg B Skull Base 2019; 80 (04) 338-351
• 29 Fukuda H, Evins AI, Burrell JC. et al. Partial anterior petrosectomies for upper basilar artery trunk aneurysms: a cadaveric and clinical study. World Neurosurg 2014; 82 (06) 1113-1119
• 30 Figueiredo EG, Zabramski JM, Deshmukh P, Crawford NR, Spetzler RF, Preul MC. Comparative analysis of anterior petrosectomy and transcavernous approaches to retrosellar and upper clival basilar artery aneurysms. Neurosurgery 2006; 58 (1, Suppl): discussion ONS13–ONS21 ONS13-ONS21
• 31 Van Gompel JJ, Alikhani P, Youssef AS, Loveren HR, Boyev KP, Agazzi S. Anterior petrosectomy: consecutive series of 46 patients with attention to approach-related complications. J Neurol Surg B Skull Base 2015; 76 (05) 379-384
• 32 Gupta SK, Salunke P. Intradural anterior petrosectomy for petroclival meningiomas: a new surgical technique and results in 5 patients: technical note. J Neurosurg 2012; 117 (06) 1007-1012
• 33 Patel CR, Wang EW, Fernandez-Miranda JC, Gardner PA, Snyderman CH. Contralateral transmaxillary corridor: an augmented endoscopic approach to the petrous apex. J Neurosurg 2018; 129 (01) 211-219
• 34 Beer-Furlan A, Abi-Hachem R, Jamshidi AO, Carrau RL, Prevedello DM. Endoscopic trans-sphenoidal surgery for petroclival and clival meningiomas. J Neurosurg Sci 2016; 60 (04) 495-502
• 35 Jittapiromsak P, Sabuncuoglu H, Deshmukh P, Nakaji P, Spetzler RF, Preul MC. Greater superficial petrosal nerve dissection: back to front or front to back?. Neurosurgery 2009; 64 (05, Suppl 2): discussion 258–259 253-258
• 36 Garcia-Ibanez E, Garcia-Ibanez JL. Middle fossa vestibular neurectomy: a report of 373 cases. Otolaryngol Head Neck Surg 1980; 88 (04) 486-490