Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

The extradural minipterional approach for the treatment of paraclinoid aneurysms: a cadaver stepwise dissection and clinical case series


Minipterional (MPT) craniotomy has recently been added to the neurosurgical armamentarium as a less invasive alternative to the pterional craniotomy for the treatment of parasellar lesions. However, its clinical applicability in the treatment of certain complex aneurysms, such as those arising in the paraclinoid region, remains unclear. To illustrate the microsurgical anatomy of a modified extradural MPT approach, which combines a classic MPT craniotomy with an extradural anterior clinoidectomy, and to demonstrate its clinical applicability in the treatment of complex paraclinoid aneurysms. A stepwise extradural MPT approach is illustrated in a cadaver study. Clinical outcome data from a series of 19 patients with 20 paraclinoid aneurysms treated surgically using the extradural MPT approach between 2016 and 2018 were retrospectively collected. In 95% of the cases, complete aneurysm occlusion was achieved. No aneurysm recurrences were seen during follow-up with a median length of 21 months. The outcome, according to the modified Rankin Scale, was 0 points in 12 patients (63%), 1 point in 6 patients (32%), and 2 points in 1 patient (5%). Four out of 6 patients (67%) with initial visual symptoms showed improvement following treatment, whereas in two (11%), vision became worse. The extradural MPT approach ensures a sufficiently large exposure of the paraclinoid region that is comparable with conventional approaches with the advantage of being minimally invasive. Our case series demonstrates the feasibility of this approach for the treatment of complex paraclinoid aneurysms.

This is a preview of subscription content, log in to check access.

Fig. 1
Fig. 2
Fig. 3
Fig. 4


  1. 1.

    Ammirati M, Bernardo A (2007) Anatomical study of the superior orbital fissure as seen during a pterional approach. J Neurosurg 106(1):151–156

  2. 2.

    Ammirati M, Spallone A, Ma J, Cheatham M, Becker D (1993) An anatomicosurgical study of the temporal branch of the facial nerve. Neurosurgery 33(6):1038–1043 discussion 1044

  3. 3.

    Andrade-Barazarte H, Kivelev J, Goehre F, Jahromi BR, Hijazy F, Moliz N, Gauthier A, Kivisaari R, Jääskeläinen JE, Lehto H, Hernesniemi JA (2015) Contralateral approach to internal carotid artery ophthalmic segment aneurysms: angiographic analysis and surgical results for 30 patients. Neurosurgery 77(1):104–112 discussion 112

  4. 4.

    Andrade-Barazarte H, Jägersberg M, Belkhair S, Tymianski R, Turel MK, Schaller K, Hernesniemi JA, Tymianski M, Radovanovic I (2017) The extended lateral supraorbital approach and extradural anterior clinoidectomy through a frontopterio-orbital window: technical note and pilot surgical series. World Neurosurg 100:159–166

  5. 5.

    Badie B (1996) Cosmetic reconstruction of temporal defect following pterional [corrected] craniotomy. Surg Neurol 45(4):383–384

  6. 6.

    Beretta F, Andaluz N, Zuccarello M (2004) Aneurysms of the ophthalmic (C6) segment of the internal carotid artery: treatment options and strategies based on a clinical series. J Neurosurg Sci 48(4):149–156

  7. 7.

    Chalouhi N, Jabbour P, Ibrahim I, Starke RM, Younes P, El Hage G, Samaha E (2013) Surgical treatment of ruptured anterior circulation aneurysms: comparison of pterional and supraorbital keyhole approaches. Neurosurgery 72(3):437–441 discussion 441-442

  8. 8.

    Chiarullo M, Mura J, Rubino P, Rabelo NN, Martinez-Perez R, Gadelha figueiredo E, Rhoton A (2019) Technical description of minimally invasive extradural anterior clinoidectomy and optic nerve decompression. Study of feasibility and proof of concept. World Neurosurg S1878875019314731

  9. 9.

    Conway JE, Raza SM, Li K, McDermott MW, Quiñones-Hinojosa A (2010) A surgical modification for performing orbitozygomatic osteotomies: technical note. Neurosurg Rev 33(4):491–500

  10. 10.

    Coscarella E, Vishteh AG, Spetzler RF, Seoane E, Zabramski JM (2000) Subfascial and submuscular methods of temporal muscle dissection and their relationship to the frontal branch of the facial nerve. Technical note. J Neurosurg 92(5):877–880

  11. 11.

    Davies JM, Lawton MT (2014) Advances in open microsurgery for cerebral aneurysms. Neurosurgery 74(Suppl 1):S7–S16

  12. 12.

    Dolenc VV (1999) A combined transorbital-transclinoid and transsylvian approach to carotid-ophthalmic aneurysms without retraction of the brain. Acta Neurochir Suppl 72:89–97

  13. 13.

    Durst CR, Starke RM, Gaughen J, Nguyen Q, Patrie J, Jensen ME, Evans AJ (2014) Vision outcomes and major complications after endovascular coil embolization of ophthalmic segment aneurysms. AJNR Am J Neuroradiol 35(11):2140–2145

  14. 14.

    Eroglu U, Shah K, Bozkurt M et al (2019) Supraorbital keyhole approach: lessons learned from 106 operative cases. World Neurosurg. https://doi.org/10.1016/j.wneu.2018.12.188

  15. 15.

    Esposito G, Dias SF, Burkhardt J-K, Fierstra J, Serra C, Bozinov O, Regli L (2019) Selection strategy for optimal keyhole approaches for middle cerebral artery aneurysms: lateral supraorbital versus minipterional craniotomy. World Neurosurg 122:e349–e357

  16. 16.

    Figueiredo EG, Deshmukh P, Nakaji P, Crusius MU, Crawford N, Spetzler RF, Preul MC (2007) The minipterional craniotomy: technical description and anatomic assessment. Neurosurgery 61(5 Suppl 2):256–264 discussion 264-265

  17. 17.

    Figueiredo EG, Deshmukh P, Zabramski JM, Preul MC, Crawford NR, Spetzler RF (2008) The pterional-transylvian approach: an analytical study. Neurosurgery 62(6 Suppl 3):1361–1367

  18. 18.

    Figueiredo EG, Teixeira MJ, Spetzler RF, Preul MC (2014) Clinical and surgical experience with the minipterional craniotomy. Neurosurgery 75(3):E324–E325

  19. 19.

    Figueiredo EG, Welling LC, Preul MC, Sakaya GR, Neville I, Spetzler RF, Teixeira MJ (2016) Surgical experience of minipterional craniotomy with 102 ruptured and unruptured anterior circulation aneurysms. J Clin Neurosci 27:34–39

  20. 20.

    Fukuda H, Evins AI, Burrell JC, Iwasaki K, Stieg PE, Bernardo A (2014) The meningo-orbital band: microsurgical anatomy and surgical detachment of the membranous structures through a frontotemporal craniotomy with removal of the anterior clinoid process. J Neurol Surg B Skull Base 75(2):125–132

  21. 21.

    Hakuba A, Nishimura S, Shirakata S, Tsukamoto M (1982) Surgical approaches to the cavernous sinus. Report of 19 cases (author’s transl). Neurol Med Chir (Tokyo) 22(4):295–308

  22. 22.

    Heros RC (2011) The supraorbital “keyhole” approach. J Neurosurg 114(3):850–851 discussion 851

  23. 23.

    Iwasaki K, Toda H, Hashikata H, Goto M, Fukuda H (2018) Extradural anterior clinoidectomy and optic canal unroofing for paraclinoid and basilar aneurysms: usefulness of a no-drill instrumental method. Acta Neurochir Suppl 129:39–42

  24. 24.

    Kim JM, Romano A, Sanan A, van Loveren HR, Keller JT (2000) Microsurgical anatomic features and nomenclature of the paraclinoid region. Neurosurgery 46(3):670–680 discussion 680-682

  25. 25.

    Komatsu F, Komatsu M, Inoue T, Tschabitscher M (2011) Endoscopic extradural anterior clinoidectomy via supraorbital keyhole: a cadaveric study. Neurosurgery 68(2 Suppl Operative):334–338 discussion 337-338

  26. 26.

    Krayenbühl N, Isolan GR, Hafez A, Yaşargil MG (2007) The relationship of the fronto-temporal branches of the facial nerve to the fascias of the temporal region: a literature review applied to practical anatomical dissection. Neurosurg Rev 30(1):8–15 discussion 15

  27. 27.

    Martínez-Pérez R, Hernández-Álvarez V, Maturana R, Mura JM (2019) The extradural minipterional pretemporal approach for the treatment of spheno-petro-clival meningiomas. Acta Neurochir 161:2577–2582. https://doi.org/10.1007/s00701-019-04064-3

  28. 28.

    Mathias RN, Lieber S, de Aguiar PHP, Maldaun MVC, Gardner P, Fernandez-Miranda JC (2016) Interfascial dissection for protection of the nerve branches to the frontalis muscles during supraorbital trans-eyebrow approach: an anatomical study and technical note. J Neurol Surg B Skull Base 77(3):265–270

  29. 29.

    Mattingly T, Kole MK, Nicolle D, Boulton M, Pelz D, Lownie SP (2013) Visual outcomes for surgical treatment of large and giant carotid ophthalmic segment aneurysms: a case series utilizing retrograde suction decompression (the “Dallas technique”). J Neurosurg 118(5):937–946

  30. 30.

    Mura J, de Oliveira E (2017) Letter to the editor regarding “The Extended Lateral Supraorbital Approach and Extradural Anterior Clinoidectomy Through a Frontopterio-Orbital Window: Technical Note and Pilot Surgical Series.”. World Neurosurg 107:1035

  31. 31.

    Nathal E, Gomez-Amador JL (2005) Anatomic and surgical basis of the sphenoid ridge keyhole approach for cerebral aneurysms. Neurosurgery 56(1 Suppl):178–185 discussion 178-185

  32. 32.

    Natori Y, Rhoton AL (1995) Microsurgical anatomy of the superior orbital fissure. Neurosurgery 36(4):762–775

  33. 33.

    Rouchaud A, Brinjikji W, Lanzino G, Cloft HJ, Kadirvel R, Kallmes DF (2016) Delayed hemorrhagic complications after flow diversion for intracranial aneurysms: a literature overview. Neuroradiology 58(2):171–177

  34. 34.

    Rychen J, Croci D, Roethlisberger M, Nossek E, Potts M, Radovanovic I, Riina H, Mariani L, Guzman R, Zumofen DW (2018) Minimally invasive alternative approaches to pterional craniotomy: a systematic review of the literature. World Neurosurg 113:163–179

  35. 35.

    Serrano LE, Archavlis E, Ayyad A, Schwandt E, Nimer A, Ringel F, Kantelhardt SR (2019) Comprehensive anatomic assessment of ipsilateral pterional versus contralateral subfrontal approaches to the internal carotid ophthalmic segment: a cadaveric study and three-dimensional simulation. World Neurosurg 128:e261–e275

  36. 36.

    Sherif C, Gruber A, Dorfer C, Bavinzski G, Standhardt H, Knosp E (2009) Ruptured carotid artery aneurysms of the ophthalmic (C6) segment: clinical and angiographic long term follow-up of a multidisciplinary management strategy. J Neurol Neurosurg Psychiatry 80(11):1261–1267

  37. 37.

    Spetzler RF, Lee KS (1990) Reconstruction of the temporalis muscle for the pterional craniotomy. Technical note. J Neurosurg 73(4):636–637

  38. 38.

    Sturiale CL, La Rocca G, Puca A, Fernandez E, Visocchi M, Marchese E, Sabatino G, Albanese A (2017) Minipterional craniotomy for treatment of unruptured middle cerebral artery aneurysms. A single-center comparative analysis with standard pterional approach as regard to safety and efficacy of aneurysm clipping and the advantages of reconstruction. Acta Neurochir Suppl 124:93–100

  39. 39.

    Turner RD, Byrne JV, Kelly ME, Mitsos AP, Gonugunta V, Lalloo S, Rasmussen PA, Fiorella D (2008) Delayed visual deficits and monocular blindness after endovascular treatment of large and giant paraophthalmic aneurysms. Neurosurgery 63(3):469–474 discussion 474-475

  40. 40.

    Welling LC, Figueiredo EG, Wen HT, Gomes MQT, Bor-Seng-Shu E, Casarolli C, Guirado VMP, Teixeira MJ (2015) Prospective randomized study comparing clinical, functional, and aesthetic results of minipterional and classic pterional craniotomies. J Neurosurg 122(5):1012–1019

  41. 41.

    Yagmurlu K, Safavi-Abbasi S, Belykh E, Kalani MYS, Nakaji P, Rhoton AL, Spetzler RF, Preul MC (2017) Quantitative anatomical analysis and clinical experience with mini-pterional and mini-orbitozygomatic approaches for intracranial aneurysm surgery. J Neurosurg 127(3):646–659

  42. 42.

    Yasargil MG, Fox JL (1975) The microsurgical approach to intracranial aneurysms. Surg Neurol 3(1):7–14

  43. 43.

    Yaşargil MG, Reichman MV, Kubik S (1987) Preservation of the frontotemporal branch of the facial nerve using the interfascial temporalis flap for pterional craniotomy. Technical article. J Neurosurg 67(3):463–466

Download references


This article was proofread by the Writing Support Center at Western University, London, Ontario, Canada.

Author information

Correspondence to Rafael Martinez-Perez.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval and informed consent

Informed consent and ethical approval were not deemed necessary by the local ethics in view of the design of the study (retrospective) and the application of strict patient privacy regulations operating in our center (cadavers were unidentified).

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Martinez-Perez, R., Joswig, H., Tsimpas, A. et al. The extradural minipterional approach for the treatment of paraclinoid aneurysms: a cadaver stepwise dissection and clinical case series. Neurosurg Rev 43, 361–370 (2020). https://doi.org/10.1007/s10143-019-01219-9

Download citation


  • Pterional
  • Minimally invasive
  • Skull base
  • Dolenc
  • Hakuba