Subscribe to RSS
Anatomical Step-by-Step Dissection of Complex Skull Base Approaches for Trainees: Surgical Anatomy of the Retrosigmoid ApproachFunding None.
Introduction Neurosurgical anatomy is traditionally taught via anatomic and operative atlases; however, these resources present the skull base using views that emphasize three-dimensional (3D) relationships rather than operative perspectives, and are frequently written above a typical resident's understanding. Our objective is to describe, step-by-step, a retrosigmoid approach dissection, in a way that is educationally valuable for trainees at numerous levels.
Methods Six sides of three formalin-fixed latex-injected specimens were dissected under microscopic magnification. A retrosigmoid was performed by each of three neurosurgery residents, under supervision by the senior authors (C.L.W.D. and M.J.L.) and a graduated skull base fellow, neurosurgeon, and neuroanatomist (M.P.C.). Dissections were supplemented with representative case applications.
Results The retrosigmoid craniotomy (aka lateral suboccipital approach) affords excellent access to cranial nerve (CN) IV to XII, with corresponding applicability to numerous posterior fossa operations. Key steps include positioning and skin incision, scalp and muscle flaps, burr hole and parasigmoid trough, craniotomy flap elevation, initial durotomy and deep cistern access, completion durotomy, and final exposure.
Conclusion The retrosigmoid craniotomy is a workhorse skull base exposure, particularly for lesions located predominantly in the cerebellopontine angle. Operatively oriented neuroanatomy dissections provide trainees with a critical foundation for learning this fundamental skull base technique. We outline a comprehensive approach for neurosurgery residents to develop their familiarity with the retrosigmoid craniotomy in the cadaver laboratory in a way that simultaneously informs rapid learning in the operating room, and an understanding of its potential for wide clinical application to skull base diseases.
Keywordsretrosigmoid - vestibular schwannoma - acoustic neuroma - meningioma - skull base - education - simulation
* Co-first authors
Received: 27 May 2019
Accepted: 13 September 2019
Article published online:
28 October 2019
© 2019. Thieme. All rights reserved.
Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany
- 1 Meyer FB. Atlas of Neurosurgery: Basic Approaches to Cranial and Vascular Procedures. Philadelphia, PA: Churchill Livingstone; 1999
- 2 Tew JM, Van Loveren HKeller JT. Atlas of Operative Microneurosurgery. Philadelphia, PA: Saunders; 1994
- 3 Rhoton Jr AL. The cerebellopontine angle and posterior fossa cranial nerves by the retrosigmoid approach. Neurosurgery 2000; 47 (3, Suppl): S93-S129
- 4 Wanibuchi M, Friedman AH, Fukushima T. Photo Atlas of Skull Base Dissection: Techniques and Operative Approaches. Stuttgart, Germany: Thieme; 2009
- 5 Carlstrom LP, Perry A, 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 2019; 80 (S 01): S1-S244
- 6 Day JD, Tschabitscher M. Anatomic position of the asterion. Neurosurgery 1998; 42 (01) 198-199
- 7 Ribas GC, Rhoton Jr. AL, Cruz OR, Peace D. Suboccipital burr holes and craniectomies. Neurosurg Focus 2005; 19 (02) E1
- 8 Uz A, Ugur HC, Tekdemir I. Is the asterion a reliable landmark for the lateral approach to posterior fossa?. J Clin Neurosci 2001; 8 (02) 146-147
- 9 Carlson ML, Tombers NM, Kerezoudis P, Celda MP, Lohse CM, Link MJ. Quality of life within the first 6 months of vestibular schwannoma diagnosis with implications for patient counseling. Otol Neurotol 2018; 39 (10) e1129-e1136
- 10 Carlson ML, Tveiten OV, Driscoll CL. et al. Long-term quality of life in patients with vestibular schwannoma: an international multicenter cross-sectional study comparing microsurgery, stereotactic radiosurgery, observation, and nontumor controls. J Neurosurg 2015; 122 (04) 833-842
- 11 Carlson ML, Tveiten OV, Driscoll CL. et al. What drives quality of life in patients with sporadic vestibular schwannoma?. Laryngoscope 2015; 125 (07) 1697-1702
- 12 Link MJ, Lund-Johansen M, Lohse CM. et al. Quality of life in patients with vestibular schwannomas following gross total or less than gross total microsurgical resection: should we be taking the entire tumor out?. Neurosurgery 2018; 82 (04) 541-547
- 13 Carlson ML, Tveiten OV, Yost KJ, Lohse CM, Lund-Johansen M, Link MJ. The minimal clinically important difference in vestibular schwannoma quality-of-life assessment: an important step beyond p <. 05. Otolaryngol Head Neck Surg 2015; 153 (02) 202-208
- 14 Kerezoudis P, Yost KJ, Tombers NM, Celda MP, Carlson ML, Link MJ. Defining the minimal clinically important difference for patients with vestibular schwannoma: are all quality-of-life scores significant?. Neurosurgery 2018; (e-pub ahead of print) doi: 10.1093/neuros/nyy467
- 15 Graffeo CS, Maria P-C, Perry A, Carlstrom LP, Driscol 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
- 16 Gross BA, Dunn IF, Du R, Al-Mefty O. Petrosal approaches to brainstem cavernous malformations. Neurosurg Focus 2012; 33 (02) E10
- 17 Horgan MA, Delashaw JB, Schwartz MS, Kellogg JX, Spektor S, McMenomey SO. Transcrusal approach to the petroclival region with hearing preservation. Technical note and illustrative cases. J Neurosurg 2001; 94 (04) 660-666
- 18 Kaylie DM, Horgan MA, Delashaw JB, McMenomey SO. Hearing preservation with the transcrusal approach to the petroclival region. Otol Neurotol 2004; 25 (04) 594-598 , discussion 598
- 19 King WA, Black KL, Martin NA, Canalis RF, Becker DP. The petrosal approach with hearing preservation. J Neurosurg 1993; 79 (04) 508-514
- 20 Bambakidis NC, Kakarla UK, Kim LJ. et al. Evolution of surgical approaches in the treatment of petroclival meningiomas: a retrospective review. Neurosurgery 2007; 61 (05) (Suppl. 02) 202-209 , discussion 209–211
- 21 Gross BA, Tavanaiepour D, Du R, Al-Mefty O, Dunn IF. Evolution of the posterior petrosal approach. Neurosurg Focus 2012; 33 (02) E7
- 22 Samii M, Gerganov V, Samii A. Improved preservation of hearing and facial nerve function in vestibular schwannoma surgery via the retrosigmoid approach in a series of 200 patients. J Neurosurg 2006; 105 (04) 527-535
- 23 Samii M, Tatagiba M. Experience with 36 surgical cases of petroclival meningiomas. Acta Neurochir (Wien) 1992; 118 (1-2): 27-32
- 24 Samii M, Tatagiba M, Carvalho GA. Resection of large petroclival meningiomas by the simple retrosigmoid route. J Clin Neurosci 1999; 6 (01) 27-30
- 25 Spetzler RF, Daspit CP, Pappas CT. The combined supra- and infratentorial approach for lesions of the petrous and clival regions: experience with 46 cases. J Neurosurg 1992; 76 (04) 588-599
- 26 Daspit CP, Spetzler RF, Pappas CT. Combined approach for lesions involving the cerebellopontine angle and skull base: experience with 20 cases--preliminary report. Otolaryngol Head Neck Surg 1991; 105 (06) 788-796
- 27 Samii M, Ammirati M. The combined supra-infratentorial pre-sigmoid sinus avenue to the petro-clival region. Surgical technique and clinical applications. Acta Neurochir (Wien) 1988; 95 (1-2): 6-12
- 28 Samii M, Ammirati M, Mahran A, Bini W, Sepehrnia A. Surgery of petroclival meningiomas: report of 24 cases. Neurosurgery 1989; 24 (01) 12-17
- 29 Spetzler RF, Daspit CP, Pappas CT. Combined approach for lesions involving the cerebellopontine angle and skull base: experience with 30 cases. Skull Base Surg 1991; 1 (04) 226-234
- 30 Alicandri-Ciufelli M, Federici G, Anschuetz L. et al. Transcanal surgery for vestibular schwannomas: a pictorial review of radiological findings, surgical anatomy and comparison to the traditional translabyrinthine approach. Eur Arch Otorhinolaryngol 2017; 274 (09) 3295-3302
- 31 Marchioni D, Gazzini L, Boaria F, Pinna G, Masotto B, Rubini A. Is endoscopic inspection necessary to detect residual disease in acoustic neuroma surgery?. Eur Arch Otorhinolaryngol 2019; 276 (08) 2155-2163
- 32 Presutti L, Alicandri-Ciufelli M, Bonali M. et al. Expanded transcanal transpromontorial approach to the internal auditory canal: pilot clinical experience. Laryngoscope 2017; 127 (11) 2608-2614
- 33 Presutti L, Magnaguagno F, Pavesi G. et al. Combined endoscopic-microscopic approach for vestibular schwannoma removal: outcomes in a cohort of 81 patients. Acta Otorhinolaryngol Ital 2014; 34 (06) 427-433