On the cutting edge: anterior transpetrosal approach – the middle fossa approach. Clinical application, surgical anatomy, and results

Nowadays, the middle cranial fossa approach (MFA) is one of the most useful operative procedures in skull base surgery. When performed properly, it provides a relevant adjunct to treating complex skull base lesions. MFA allows one to resect the anterior petrous bone (anterior petrosectomy), open the internal auditory canal (IAC), and access the lateral wall of the cavernous sinus and the infratemporal fossa. Knowledge of the anatomical structures of the middle cranial fossa and cavernous sinus is mandatory to perform this approach. We report in detail the standard extradural subtemporal route for the anterior petrosectomy and MFA. The main indications for this approach are intradural lesions localized medially to the trigeminal nerve, subtemporal interdural and extradural tumours and neoplasms involving the IAC (including IAC pathology). Moreover, we describe the extended middle fossa approach, consisting in the anterior extension of MFA, indicated for intradural tumours of the superior cerebello-pontine angle and of prepontine clivus (retroclival lesions, ventral brainstem tumours, and cavernomas), for infratemporal fossa lesions, and cavernous sinus pathologies. Even if the anatomical landmarks of the middle cranial fossa and lateral skull base are well known, training with cadaver dissection is necessary for any skull-base surgeon to perform an optimum MFA. The cadaver-lab dissections simplify the learning of anatomical structures, and prepare the surgeon properly for this technically challenging approach.

1. Al-Mefty O., Ayoubi S., Gaber E. Trigeminal schwannomas: removal of dumbbell-shaped tumours through the expanded Meckel cave and outcomes of cranial nerve function. J Neurosurg. 2002 Mar; 96(3): 453–463. https://doi.org/10.3171/jns.2002.96.3.0453. PMID: 11883829.

2. Day J.D., Fukushima T., Giannotta S.L. Microanatomical study of the extradural middle fossa approach to the petroclival and posterior cavernous sinus region: description of the rhomboid construct. Neurosurgery. 1994 Jun; 34(6): 1009–1016; discussion 1016. https://doi.org/10.1227/00006123-199406000-00009. PMID: 8084385.

3. Day J.D., Fukushima T., Giannotta S.L. Innovations in surgical approach: lateral cranial base approaches. Clin Neurosurg. 1996; 43: 72–90. PMID: 9247796.

4. Day J.D., Fukushima T. The surgical management of trigeminal neuromas. Neurosurgery. 1998 Feb; 42(2): 233–240; discussion 240–241. https://doi.org/10.1097/00006123-199802000-00015. PMID: 9482173.

5. Inoue T., Rhoton A.L. Jr, Theele D., Barry M.E. Surgical approaches to the cavernous sinus: a microsurgical study. Neurosurgery. 1990 Jun; 26(6): 903–932. https://doi.org/10.1097/00006123-199006000-00001. PMID: 2362670.

6. Sameshima T., Mastronardi L., Friedman A., Fukushima T. (eds) Middle fossa dissection for extended middle fossa and anterior petrosectomy approach. Fukushima’s microanatomy and dissection of the temporal bone for surgery of acoustic neuroma, and petroclival meningioma, 2007, 2nd edn. AF Neurovideo, Raleigh. P. 51–83.

7. Samii M., Migliori M.M., Tatagiba M., Babu R. Surgical treatment of trigeminal schwannomas. J Neurosurg. 1995 May; 82(5): 711–718. https://doi.org/10.3171/jns.1995.82.5.0711. PMID: 7714594.

8. Mastronardi L., Sameshima T., Ducati A., et al. Extradural middle fossa approach. Proposal of a learning method: the rule of two fans. Technical note. Skull Base. 2006 Aug; 16(3): 181–184. https://doi.org/: 10.1055/s-2006-939676. PMID: 17268592.

9. Day J.D., Kellogg J.X., Tschabitscher M., Fukushima T. Surface and superficial surgical anatomy of the posterolateral cranial base: significance for surgical planning and approach. Neurosurgery. 1996 Jun; 38(6): 1079–1083; discussion 1083-1084. PMID: 8727136.

10. Kawase T., van Loveren H., Keller J.T., Tew J.M. Meningeal architecture of the cavernous sinus: clinical and surgical implications. Neurosurgery. 1996 Sep; 39(3): 527–534; discussion 534–536. https://doi.org/10.1097/00006123-199609000-00019. PMID: 8875483.

11. Maina R., Ducati A., Lanzino G. The middle cranial fossa: morphometric study and surgical considerations. Skull Base. 2007 Nov; 17(6): 395–403. https://doi.org/10.1055/s-2007-991117. PMID: 18449332.

12. Kartush J.M., Kemink J.L., Graham M.D. The arcuate eminence. Topographic orientation in middle cranial fossa surgery. Ann Otol Rhinol Laryngol. 1985 Jan-Feb; 94 (1 Pt 1): 25–28. https://doi.org/10.1177/000348948509400106. PMID: 3970502.

13. Cokkeser Y., Aristegui M., Naguib M.B., et al. Identification of internal acoustic canal in the middle cranial fossa approach: a safe technique. Otolaryngol Head Neck Surg. 2001 Jan; 124(1): 94–98. https://doi.org/10.1067/mhn.2001.111712. PMID: 11228461.

14. El-Khouly H., Fernandez-Miranda J., Rhoton A.L. Jr. Blood supply of the facial nerve in the middle fossa: the petrosal artery. Neurosurgery. 2008 May; 62(5 Suppl 2): ONS 297–303; discussion ONS 303–304. https://doi.org/10.1227/01.neu.0000326010.53821.a3. PMID: 18596507.

15. Scheich M., Ginzkey C., Ehrmann Müller D., et al. Complications of the middle cranial fossa approach for acoustic neuroma removal. J Int Adv Otol. 2017 Aug; 13(2): 186–190. https://doi.org/10.5152/iao.2017.3585. PMID: 28816690.

16. Angeli S. Middle fossa approach: indications, technique, and results. Otolaryngol Clin North Am. 2012 Apr; 45(2): 417–438, ix. https://doi.org/10.1016/j.otc.2011.12.010. PMID: 22483825.