Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Endoscopic Endonasal Approach to the Sellar and Parasellar Regions

Abstract

Introduction Surgery of the sellar and parasellar regions can be challenging due to the complexity of neurovascular relationships. The main goal of this study is to develop an educational resource to help trainees understand the pertinent anatomy and procedural steps of the endoscopic endonasal approaches (EEAs) to the sellar and parasellar regions.

Methods Ten formalin-fixed latex-injected specimens were dissected. Endoscopic endonasal transsphenoidal transsellar, transtuberculum-transplanum, and transcavernous approaches were performed by a neurosurgery trainee, under supervision from the senior authors and a PhD in anatomy with advanced neuroanatomy experience. Dissections were supplemented with representative case applications.

Results Endoscopic endonasal transsphenoidal approaches afford excellent direct access to sellar and parasellar regions. After a wide sphenoidotomy, a limited sellar osteotomy opens the space to sellar region and medial portion of the cavernous sinus. To reach the suprasellar space (infrachiasmatic and suprachiasmatic corridors), a transplanum-prechiasmatic sulcus-transtuberculum adjunct is needed. The transcavernous approach gains access to the contents of the cavernous sinus and both medial (posterior clinoid and interpeduncular cistern) and lateral structures of the retrosellar region.

Conclusion The anatomical understanding and technical skills required to confidently remove skull base lesions with EEAs are traditionally gained after years of specialized training. We comprehensively describe EEAs to sellar and parasellar regions for trainees to build knowledge and improve familiarity with these approaches and facilitate comprehension and learning in both the surgical anatomy laboratory and the operating room.

Keywords

step-by-step description - anatomical understanding - skull base surgery - endoscopic endonasal approaches - transsellar approach - transcavernous approach - transplanum approach

• References

• 1 Emanuelli E, Zanotti C, Munari S, Baldovin M, Schiavo G, Denaro L. Sellar and parasellar lesions: multidisciplinary management. Acta Otorhinolaryngol Ital 2021; 41 (Suppl. 01) S30-S41
• 2 Das K, Spencer W, Nwagwu CI. et al. Approaches to the sellar and parasellar region: anatomic comparison of endonasal-transsphenoidal, sublabial-transsphenoidal, and transethmoidal approaches. Neurol Res 2001; 23 (01) 51-54
• 3 Louis RG, Eisenberg A, Barkhoudarian G, Griffiths C, Kelly DF. Evolution of minimally invasive approaches to the sella and parasellar region. Int Arch Otorhinolaryngol 2014; 18 (Suppl. 02) S136-S148
• 4 Spencer WR, Das K, Nwagu C. et al. Approaches to the sellar and parasellar region: anatomic comparison of the microscope versus endoscope. Laryngoscope 1999; 109 (05) 791-794
• 5 Spencer WR, Levine JM, Couldwell WT, Brown-Wagner M, Moscatello A. Approaches to the sellar and parasellar region: a retrospective comparison of the endonasal-transsphenoidal and sublabial-transsphenoidal approaches. Otolaryngol Head Neck Surg 2000; 122 (03) 367-369
• 6 Cavallo LM, Somma T, Solari D. et al. Endoscopic endonasal transsphenoidal surgery: history and evolution. World Neurosurg 2019; 127: 686-694
• 7 Isolan GR, Braga FLS, Campero A. et al. Microsurgical and endoscopic anatomy of the cavernous sinus. Arq Bras Neurocir Brazil Neurosurg 2020; 39: 83-94
• 8 Cavallo LM, Cappabianca P, Galzio R, Iaconetta G, de Divitiis E, Tschabitscher M. Endoscopic transnasal approach to the cavernous sinus versus transcranial route: anatomic study. Neurosurgery 2005; 56 (Suppl. 02) 379-389 , discussion 379–389
• 9 Oyama K, Tahara S, Hirohata T. et al. Surgical anatomy for the endoscopic endonasal approach to the ventrolateral skull base. Neurol Med Chir (Tokyo) 2017; 57 (10) 534-541
• 10 Fernandez-Miranda JC, Zwagerman NT, Abhinav K. et al. Cavernous sinus compartments from the endoscopic endonasal approach: anatomical considerations and surgical relevance to adenoma surgery. J Neurosurg 2018; 129 (02) 430-441
• 11 Truong HQ, Lieber S, Najera E, Alves-Belo JT, Gardner PA, Fernandez-Miranda JC. The medial wall of the cavernous sinus. Part 1: surgical anatomy, ligaments, and surgical technique for its mobilization and/or resection. J Neurosurg 2018; 131 (01) 122-130
• 12 Cohen-Cohen S, Gardner PA, Alves-Belo JT. et al. The medial wall of the cavernous sinus. Part 2: selective medial wall resection in 50 pituitary adenoma patients. J Neurosurg 2018; 131 (01) 131-140
• 13 Iwanaga J, Anand MK, Camacho A. et al. Surgical anatomy of the internal carotid plexus branches to the abducens nerve in the cavernous sinus. Clin Neurol Neurosurg 2020; 191: 105690
• 14 Morera Porras V, Zadeh G, Gentili F, Fernandez-Miranda J. Endoscopic anatomy and approach of the cavernous sinus. J Neurol Surg B Skull Base 2014; 75: A114
• 15 Krisht AF. Transcavernous approach to diseases of the anterior upper third of the posterior fossa. Neurosurg Focus 2005; 19 (02) E2
• 16 Wagenmann M, Schipper J. The transnasal approach to the skull base. From sinus surgery to skull base surgery. GMS Curr Top Otorhinolaryngol Head Neck Surg 2011; 10: Doc08
• 17 Di Somma A, Torales J, Cavallo LM. et al. Defining the lateral limits of the endoscopic endonasal transtuberculum transplanum approach: anatomical study with pertinent quantitative analysis. J Neurosurg 2018; 130 (03) 848-860
• 18 Martinez-Perez R, Silveira-Bertazzo G, Carrau RL, Prevedello DM. The importance of landmarks in endoscopic endonasal reinterventions: the transpterygoid transcavernous approach. Acta Neurochir (Wien) 2020; 162 (04) 875-880
• 19 Gatto F, Perez-Rivas LG, Olarescu NC. et al; on behalf of the ENEA Young Researchers Committee (EYRC). Diagnosis and treatment of parasellar lesions. Neuroendocrinology 2020; 110 (9-10): 728-739
• 20 Kocaoğullar Y, Avci E, Fossett D, Caputy A. The extradural subtemporal keyhole approach to the sphenocavernous region: anatomic considerations. Minim Invasive Neurosurg 2003; 46 (02) 100-105
• 21 Ciporen JN, Moe KS, Ramanathan D. et al. Multiportal endoscopic approaches to the central skull base: a cadaveric study. World Neurosurg 2010; 73 (06) 705-712
• 22 El-Fiki ME, Aly A, Elwany S. Binasal endoscopic approach to the sellar region: experience and outcome analysis of 80 cases. J Neurol Surg B Skull Base 2012; 73 (04) 287-291
• 23 Fernandez-Miranda JC, Gardner PA, Rastelli Jr MM. et al. Endoscopic endonasal transcavernous posterior clinoidectomy with interdural pituitary transposition. J Neurosurg 2014; 121 (01) 91-99
• 24 Kassam A, Snyderman CH, Mintz A, Gardner P, Carrau RL. Expanded endonasal approach: the rostrocaudal axis. Part I. Crista galli to the sella turcica. Neurosurg Focus 2005; 19 (01) E3
• 25 Kassam A, Snyderman CH, Mintz A, Gardner P, Carrau RL. Expanded endonasal approach: the rostrocaudal axis. Part II. Posterior clinoids to the foramen magnum. Neurosurg Focus 2005; 19 (01) E4
• 26 Leonel LCP, Carlstrom LP, Graffeo CS. 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 2021; 82 (Suppl. 03) e248-e258
• 27 Agosti E, Saraceno G, Qiu J. et al. Quantitative anatomical comparison of transnasal and transcranial approaches to the clivus. Acta Neurochir (Wien) 2020; 162 (03) 649-660
• 28 Belotti F, Doglietto F, Schreiber A. et al. Modular classification of endoscopic endonasal transsphenoidal approaches to sellar region: anatomic quantitative study. World Neurosurg 2018; 109: e281-e291
• 29 Cappabianca P, Doglietto F, Gentili F, Nicolai P. Endoscopic skull base surgery: where on the parabola?. J Neurosurg Sci 2016; 60 (04) 438-440
• 30 Peris-Celda M, Kucukyuruk B, Monroy-Sosa A, Funaki T, Valentine R, Rhoton Jr AL. The recesses of the sellar wall of the sphenoid sinus and their intracranial relationships. Neurosurgery 2013;73(suppl operative 2):ons117–ons131, discussion ons131
• 31 Nunes CF, Prevedello DMS, Carrau RL, da Fonseca COP, Landeiro JA. Morphometric analysis of the medial opticocarotid recess and its anatomical relations relevant to the transsphenoidal endoscopic endonasal approaches. Acta Neurochir (Wien) 2016; 158 (02) 319-324
• 32 Kikuchi R, Toda M, Wakahara S, Fujiwara H, Jinzaki M, Yoshida K. Analysis of the medial opticocarotid recess in patients with pituitary macroadenoma using three-dimensional images. World Neurosurg 2016; 93: 139-143
• 33 Amin SM, Nasr AY, Saleh HA, Foad MM, Herzallah IR. Endoscopic orientation of the parasellar region in sphenoid sinus with ill-defined bony landmarks: an anatomic study. Skull Base 2010; 20 (06) 421-428
• 34 Sandu K, Monnier P, Pasche P. Anatomical landmarks for transnasal endoscopic skull base surgery. Eur Arch Otorhinolaryngol 2012; 269 (01) 171-178
• 35 Labib MA, Prevedello DM, Fernandez-Miranda JC. et al. The medial opticocarotid recess: an anatomic study of an endoscopic “key landmark” for the ventral cranial base. Neurosurgery 2013;72(suppl operative 1):66–76, discussion 76
• 36 Ozcan T, Yilmazlar S, Aker S, Korfali E. Surgical limits in transnasal approach to opticocarotid region and planum sphenoidale: an anatomic cadaveric study. World Neurosurg 2010; 73 (04) 326-333
• 37 Farrell CJ, Nyquist GG, Farag AA, Rosen MR, Evans JJ. Principles of pituitary surgery. Otolaryngol Clin North Am 2016; 49 (01) 95-106
• 38 Lobo B, Heng A, Barkhoudarian G, Griffiths CF, Kelly DF. The expanding role of the endonasal endoscopic approach in pituitary and skull base surgery: a 2014 perspective. Surg Neurol Int 2015; 6: 82
• 39 Vellutini Ede AS, Beer-Furlan A, Stamm AC. Endoscopic transsellar approach to pituitary adenomas with cavernous sinus invasion: is this just a matter of lateral extension?. Pituitary 2016; 19 (03) 342-343
• 40 Taniguchi M, Hosoda K, Akutsu N, Takahashi Y, Kohmura E. Endoscopic endonasal transsellar approach for laterally extended pituitary adenomas: volumetric analysis of cavernous sinus invasion. Pituitary 2015; 18 (04) 518-524
• 41 Mascarenhas L, Moshel YA, Bayad F. et al. The transplanum transtuberculum approaches for suprasellar and sellar-suprasellar lesions: avoidance of cerebrospinal fluid leak and lessons learned. World Neurosurg 2014; 82 (1-2): 186-195
• 42 d'Avella E, De Notaris M, Enseñat J. et al. The extended endoscopic endonasal transplanum transtuberculum approach to the anterior communicating artery complex: anatomic study. Acta Neurochir (Wien) 2015; 157 (09) 1495-1503 , discussion 1503
• 43 Barazi SA, Pasquini E, D'Urso PI. et al. Extended endoscopic transplanum-transtuberculum approach for pituitary adenomas. Br J Neurosurg 2013; 27 (03) 374-382
• 44 Cavalcante R, Marques R, Santos V. et al. Expanded endoscopic endonasal transtuberculum / transplanum approach to the suprasellar area: a stepwise approach. Arq Bras Neurocir Brazil Neurosurg 2016; 35: 128-134
• 45 Yohannan DG, Krishnapillai R, Suresh R, Ramnarayan S, Peethambaran AK, John NJ. Can the angle between optic nerves indicate whether optic chiasm is prefixed, normofixed or postfixed? An anatomical study with radiologic and neurosurgical implications. Surg Radiol Anat 2016; 38 (10) 1175-1181
• 46 Omay SB, Almeida JP, Chen YN. et al. Is the chiasm-pituitary corridor size important for achieving gross-total resection during endonasal endoscopic resection of craniopharyngiomas?. J Neurosurg 2018; 129 (03) 642-647
• 47 Abuzayed B, Tanriover N, Gazioglu N, Ozlen F, Cetin G, Akar Z. Endoscopic anatomy and approaches of the cavernous sinus: cadaver study. Surg Radiol Anat 2010; 32 (05) 499-508
• 48 Harris FS, Rhoton AL. Anatomy of the cavernous sinus. A microsurgical study. J Neurosurg 1976; 45 (02) 169-180
• 49 Rindler RS, Leonel LC, Graepel S. et al. The endonasal midline inferior intercavernous approach to the cavernous sinus: technical note, cadaveric step-by-step illustration, and case presentation. Acta Neurochirurgica 2022; Jun 23: 1-8
• 50 Kassam AB, Prevedello DM, Thomas A. et al. Endoscopic endonasal pituitary transposition for a transdorsum sellae approach to the interpeduncular cistern. Neurosurgery 2008;62(3, suppl 1):–57, 72, discussion 72–74