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Efficacy of endolymphatic sac decompression for Ménière’s disease: Long-term follow-up by electrocochleography.

Abstract Objectives To explore the long-term efficacy and possible
mechanism of endolymphatic sac decompression (ESD) in the treatment of
Meniere’s disease(MD) by electrocochleography. Design Prospective cohort
study. Setting “Blinded for review” Participants A total of 85
patients with MD who underwent unilateral ESD between June 2015 and
November 2019 at“Blinded for review”were enrolled. Main outcome
measures The Dizziness Handicap Inventory (DHI), Tinnitus Handicap
Inventory (THI), pure tone audiometry, and electrocochleography were
used for assessment. The mean follow-up time was 26 months (range: 7–60
months). Results The number of vertigo episodes was significantly
reduced following ESD compared to before the surgery
(P<0.005), and all patients achieved complete or basic control
of vertigo as evidenced by a decrease in DHI score (P<0.005).
THI scores of patients with tinnitus were also lower after as compared
to before ESD (P<0.005), whereas no significant change in
average hearing threshold of the affected side was observed
(P>0.05). The cochlear summating potential (SP)/auditory
nerve action potential (AP) area ratio in the electrocochleogram of the
affected side was negatively correlated with DHI score (rs=−0.159,
P=0.0074). Conclusions ESD achieved effective long-term control of
vertigo in MD patients and improved the associated tinnitus without any
obvious damage to hearing. Electrocochleography was useful for
postoperative monitoring; the SP/AP area ratio of the affected side was
closely related to the improvement of postoperative vertigo, possibly
reflecting greater relief of pressure in the endolymphatic sac.
Keypoints •ESD provided long-term control of vertigo in MD patients and
improved the accompanying tinnitus without obviously damaging hearing.
•ECochG is useful for monitoring the postoperative outcome of ESD. •The
SP/AP area ratio of the affected side was closely related to the
improvement of postoperative vertigo. •The endolymphatic sac is a
“decompression reservoir” of the membranous labyrinth. •ESD may
provide space for expansion of the endolymphatic sac and relieve
pressure within the membranous labyrinth caused by endolymphatic
hydrops, thereby reducing the risk of sac rupture and restoring pressure
balance to reduce the sensation of vertigo.