Rasim YILMAZER, Ömer ERDUR, Ayça BAŞKADEM YILMAZER

A new landmark for superior semicircular canal: Spine of Henle

Objectives: In this study, we aimed to investigate whether the spine of Henle could a new landmark for the localization of the superior semicircular canal SCC . Patients and Methods: Between March 2014 and March 2015, a total of 30 adult cadaveric temporal bones were used in this study. All temporal bones were positioned and, then, canal-wall up mastoidectomy and facial recess approach were performed. The landmarks such as sigmoid sinus SS , middle cranial fossa dura MCFD , posterior cranial fossa dura PCFD , SCCs, short process of the incus, facial nerve FN , and chorda tympani nerve were identified. The shortest distances between the spine of Henle and the following structures were measured: i superior SCC; ii lateral SCC; iii posterior SCC; iv MCFD; v PCFD; vi SS; and vii FN. All measurements were performed using a digital caliper. Results: After excluding three temporal bones with absent spine of Henle, 27 temporal bones were studied. The mean distances between the spine of Henle and the superior, lateral and posterior SCCs, MCFD, PCFD, SS, and FN were 20.3±2.4, 15.9±2.1, 17.8±2.0, 13.7±2.9, 19.0±2.7, 14.9±3.6, and 15.8±1.7 mm, respectively. The distances between the spine of Henle and superior SCC were higher in the temporal bones, while the distances between the spine of Henle and MCFD were higher than the mean values. Similar differences were found for the distances between the spine of Henle and the lateral and posterior SCCs and PCFD. Conclusion: Based on our study results, the spine of Henle can be used as a landmark for the localization of the superior SCC during mastoidectomy and superior SCC surgeries.

Keywords:

Mastoid, mastoidectomy semicircular canals, spine, temporal bone,

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Aslan A, Mutlu C, Celik O, Govsa F, Ozgur T, Egrilmez M. Surgical implications of anatomical landmarks on the lateral surface of the mastoid bone. Surg Radiol Anat 2004;26:263-7.
Ulug T, Ozturk A, Sahinoglu K. A multipurpose landmark for skull-base surgery: Henle's spine. J Laryngol Otol 2005;119:856-61.
Minor LB. Superior canal dehiscence syndrome. Am J Otol 2000;21:9-19.
Chung LK, Ung N, Spasic M, Nagasawa DT, Pelargos PE, Thill K, et al. Clinical outcomes of middle fossa craniotomy for superior semicircular canal dehiscence repair. J Neurosurg 2016;125:1187-93.
Banakis Hartl RM, Cass SP. Effectiveness of transmastoid plugging for semicircular canal dehiscence syndrome. Otolaryngol Head Neck Surg 2018;158:534-40.
Silverstein H, Kartush JM, Parnes LS, Poe DS, Babu SC, Levenson MJ, et al. Round window reinforcement for superior semicircular canal dehiscence: a retrospective multi-center case series. Am J Otolaryngol 2014;35:286-93.
Goddard JC, Wilkinson EP. Outcomes following semicircular canal plugging. Otolaryngol Head Neck Surg 2014;151:478-83.
Brantberg K, Bergenius J, Mendel L, Witt H, Tribukait A, Ygge J. Symptoms, findings and treatment in patients with dehiscence of the superior semicircular canal. Acta Otolaryngol 2001;121:68-75.
Agrawal SK, Parnes LS. Transmastoid superior semicircular canal occlusion. Otol Neurotol 2008;29:363-7.
Zhao YC, Somers T, van Dinther J, Vanspauwen R, Husseman J, Briggs R. Transmastoid repair of superior semicircular canal dehiscence. J Neurol Surg B Skull Base 2012;73:225-9.
Beyea JA, Agrawal SK, Parnes LS. Transmastoid semicircular canal occlusion: a safe and highly effective treatment for benign paroxysmal positional vertigo and superior canal dehiscence. Laryngoscope 2012;122:1862-6.