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Unmitigated negative nasopharyngeal pressure is associated with attic retraction pocket formation: LaPlace's law in action

Published online by Cambridge University Press:  11 October 2021

Nilesh H Mahajan
Affiliation:
Vijaya ENT Care Centre, Superspeciality Otology Centre, Bangalore560003, India
H Vijayendra*
Affiliation:
Vijaya ENT Care Centre, Superspeciality Otology Centre, Bangalore560003, India
Vinay Kumar Vijayendra
Affiliation:
Vijaya ENT Care Centre, Superspeciality Otology Centre, Bangalore560003, India
Miriam Redleaf
Affiliation:
Department of Otology-Neurotology, University of Illinois, Chicago Department of Neurosurgery, University of New Mexico, Albuquerque, USA
*
Author for correspondence: Dr Nilesh H Mahajan, Vijaya ENT Care Centre, Superspeciality Otology Centre, No. 1, 9th Cross, Malleshwaram, Bangalore560003, India E-mail : [email protected]

Abstract

Background

Decades of clinical observation have led our subspecialty team to suspect that negative nasopharyngeal pressure is associated with attic retraction pocket formation. Furthermore, LaPlace's law, which states that the pressure within a sphere varies with the inverse of the radius, provides the dynamic explanation for why the attic area of the tympanic membrane tends to retract more frequently than the pars tensa.

Methods

The attic retraction pockets of 154 patients were classified into grades of severity (grades I–V). Impedance audiometry of middle-ear pressure was measured in the resting state, and after sniffing, swallowing and the Valsalva manoeuvre.

Results

Negative nasopharyngeal pressure (sniffing) caused a diminution of middle-ear pressure of −5 daPa on average in normal ears, and of −24 daPa to −45 daPa for tympanic membranes with attic retraction pockets of grade I to grade V.

Conclusion

Attic retraction pockets are associated with greater collapse of middle-ear volume when negative pressure is created in the nasopharynx. LaPlace's law, and the composition of the pars flaccida, suggests an explanation for why the attic region retracts more than the pars tensa.

Type
Main Articles
Copyright
Copyright © The Author(s), 2021. Published by Cambridge University Press

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Footnotes

Dr Nilesh H Mahajan takes responsibility for the integrity of the content of the paper

References

Vijayendra, H, Mahajan, NH, Vijayendra, V, Ramdass, S. Attic retraction pockets: classification system. Laryngoscope 2020;130:2034–9CrossRefGoogle ScholarPubMed
Kobayashi, T, Yaginuma, Y, Takahashi, Y, Takasaka, T. Incidence of sniff-related cholesteatomas. Acta Otolaryngol 1996;161:74–6CrossRefGoogle Scholar
Falk, B, Magnuson, B. Evacuation of the middle ear by sniffing: a cause of high negative pressure and development of middle ear disease. Otolaryngol Head Neck Surg 1984;92:312–18CrossRefGoogle ScholarPubMed
Mansour, S. Comprehensive and clinical anatomy of the middle ear. In: Mansour, S, Magnan, J, Haidar, H, Nicolas, K, Louryan, S, eds. Comprehensive and Clinical Anatomy of the Middle Ear, 2nd edn. Berlin: Springer 2019;1948CrossRefGoogle Scholar
Thiriet, M. Tissue functioning and remodeling in the circulatory and ventilatory systems. In: Thiriet, M, ed. Biomathematical and Biomechanical Modeling of the Circulatory and Ventilatory Systems. Berlin: Springer 2013;790–4Google Scholar
Law of LaPlace (experiment). In: https://youtu.be/_btWTwDVRj8 [7 October 2021]Google Scholar
Sade, J, Fuchs, C, Luntz, M. Shrapnell membrane and mastoid pneumatization. Arch Otolaryngol Head Neck Surg 1997;123:584–8CrossRefGoogle ScholarPubMed
Marchioni, D, Mattioli, F, Alicandri-Ciufelli, M, Presutti, L. Prevalence of ventilation blockages in patients affected by attic pathology: a case-control study. Laryngoscope 2013;123:2845–53CrossRefGoogle ScholarPubMed
Magnuson, B. Tubal closing failure in retraction type cholesteatoma and adhesive middle ear lesions. Acta Otolaryngol 1978;86:408–17CrossRefGoogle ScholarPubMed