Anatomical Factors Influencing Selective Vestibular Neurectomy: A Comparison of Posterior Fossa Approaches

Abstract

Objectives To identify measurable anatomical factors that may guide the surgical approach for posterior fossa selective vestibular neurectomy (SVN) and predict identification of the vestibulocochlear cleavage (VCC) plane.

Study Design Dissection of fixed cadaveric heads through retrolabyrinthine and retrosigmoid-internal auditory canal (RSG-IAC) approaches with measurement of landmarks.

Setting Cadaveric dissection model.

Main Outcome Measures Area of the Trautmann triangle (TT) and the distance from the posterior semicircular canal to the anterior border of the sigmoid along the posterior Donaldson line (pDL). VCC planes from each approach were calculated and compared.

Results Overall mean pDL was 8.53 mm (range: 5–11.5 mm); mean TT area was 124 mm² (range: 95–237 mm²). The VCC was identified in 63% of ears through the retrolabyrinthine (RVN) approach alone, whereas 37% of ears required the RSG-IAC approach. In ears requiring IAC dissection, the VCC was found within 1 to 2 mm distal to the porus. The pDL (p < 0.05) and area of TT (p < 0.05) were significantly larger in the RVN group compared with the RSG-IAC group.

Conclusion Ears amenable to the RVN approach had a greater pDL and TT area. These anatomical measurements may have a role in surgical planning and the choice of approach for SVN.

Keywords

vestibular neurectomy - Meniere disease - retrolabyrinthine - retrosigmoid - vertigo

Note

This article was presented as a poster at the Triologic meeting, May 14–18, 2014, Las Vegas, Nevada, United States.

• References

• 1 Committee on Hearing and Equilibrium guidelines for the diagnosis and evaluation of therapy in Meniere's disease. American academy of Otolaryngology-Head and Neck Foundation, Inc. Otolaryngol Head Neck Surg 1995; 113 (3) 181-185
• 2 Frazier C. Intracranial division of the auditory nerve for persistent aural vertigo. Surg Gynecol Obstet 1912; 14: 524-529
• 3 Green RE, Douglass CC. Intracranial division of the eighth nerve for Ménière's disease; a follow-up study of patients operated on by Dr. Walter E. Dandy. Ann Otol Rhinol Laryngol 1951; 60 (3) 610-621
• 4 Silverstein H, Norrell H. Retrolabyrinthine surgery: a direct approach to the cerebellopontine angle. Otolaryngol Head Neck Surg 1980; 88 (4) 462-469
• 5 House WF. Surgical exposure of the internal auditory canal and its contents through the middle, cranial fossa. Laryngoscope 1961; 71: 1363-1385
• 6 Angeli SI, Telischi FF, Eshraghi AA. Middle fossa vestibular neurectomy for refractory vertigo: less is more. Ann Otol Rhinol Laryngol 2014; 123 (5) 359-364
• 7 Pappas Jr DG, Pappas Sr DG. Vestibular nerve section: long-term follow-up. Laryngoscope 1997; 107 (9) 1203-1209
• 8 Zini C, Mazzoni A, Gandolfi A, Sanna M, Pasanisi E. Retrolabyrinthine versus middle fossa vestibular neurectomy. Am J Otol 1988; 9 (6) 448-450
• 9 Silverstein H, Willcox Jr TO. Vestibular nerve section. Otolaryngol Clin North Am 1994; 27 (2) 347-362
• 10 Silverstein H. Cochlear and vestibular gross and histologic anatomy (as seen from postauricular approach). Otolaryngol Head Neck Surg 1984; 92 (2) 207-211
• 11 Contino M, Mangini A, Lemma MG , et al. A geometric approach to aortic root surgical anatomy. Eur J Cardiothorac Surg 2015;
• 12 Liu Y, Han J, Zhou X, Luan D, Xie F, Gao K. Comparative study of endolymphatic sac decompression and vestibular neurectomy in intractable Meniere's disease. Indian J Otolaryngol Head Neck Surg 2015; 67 (1) 51-55
• 13 McKenna MJ, Nadol Jr JB, Ojemann RG, Halpin C. Vestibular neurectomy: retrosigmoid-intracanalicular versus retrolabyrinthine approach. Am J Otol 1996; 17 (2) 253-258
• 14 Liu X, Cheng Jr K, Li L , et al. Three-dimensional anatomic analysis of retrosigmoid approach with thin-section computed tomographic image. J Craniofac Surg 2015; 26 (2) 526-527
• 15 Megerian CA, Hanekamp JS, Cosenza MJ, Litofsky NS. Selective retrosigmoid vestibular neurectomy without internal auditory canal drill-out: an anatomic study. Otol Neurotol 2002; 23 (2) 218-223
• 16 Terasaka S, Sawamura Y, Fukushima T. Topography of the vestibulocochlear nerve. Neurosurgery 2000; 47 (1) 162-168
• 17 Charalampakis S, Koutsimpelas D, Gouveris H, Mann W. Post-operative complications after removal of sporadic vestibular schwannoma via retrosigmoid-suboccipital approach: current diagnosis and management. Eur Arch Otorhinolaryngol 2011; 268 (5) 653-660
• 18 Schaller B, Baumann A. Headache after removal of vestibular schwannoma via the retrosigmoid approach: a long-term follow-up-study. Otolaryngol Head Neck Surg 2003; 128 (3) 387-395
• 19 Silverstein H, Norrell H, Smouha E, Jones R. Combined retrolab-retrosigmoid vestibular neurectomy. An evolution in approach. Am J Otol 1989; 10 (3) 166-169