Endolymphatic subarachnoid shunt operation for idiopathic endolymphatic hydrops

Area of Science:

• Otolaryngology
• Neurosurgery
• Audiology

Background:

• Idiopathic endolymphatic hydrops is a condition characterized by vertigo and hearing loss.
• Endolymphatic subarachnoid shunt surgery was developed to treat this condition.
• Previous reports showed limited success in vertigo control after 5 years.

Purpose of the Study:

• To evaluate the long-term efficacy and safety of endolymphatic subarachnoid shunt surgery.
• To assess the impact of the surgery on vertigo control and hearing preservation over an extended follow-up period.
• To discuss additional observations regarding endolymphatic sac operations.

Main Methods:

• Analysis of a cohort of patients who underwent endolymphatic subarachnoid shunt surgery.
• Extended postoperative follow-up, averaging 12.5 years (range 68-182 months).
• Assessment of vertigo control (satisfactory, improved, no improvement) and hearing acuity changes.

Main Results:

• Satisfactory vertigo control decreased to 35% in the long-term follow-up (initially 41%).
• Significant hearing decline (moderate to profound sensorineural deafness) occurred in one-third of patients.
• Unilateral surgery in bilateral cases showed better hearing outcomes in the unoperated ear, suggesting the shunt may negatively impact hearing.

Conclusions:

• Endolymphatic subarachnoid shunt surgery offers disappointing long-term vertigo control for idiopathic endolymphatic hydrops.
• The procedure does not preserve hearing and can lead to significant sensorineural hearing loss.
• The success rate of the surgery diminishes with longer observation periods.