Endolymphatic Sac Surgery for Otolaryngology Examinations

OtoPrep Endolymphatic sac surgical anatomy
Endolymphatic Sac Surgery Anatomy for Otolaryngology Examinations

Anatomy and Physiology

The endolymphatic sac is an extension of the membranous labyrinth, located in the posterior part of the temporal bone. It regulates endolymphatic fluid pressure and volume, crucial for inner ear function.

How well do you know Endolymphatic Sac Anatomy?

Identify these structures on the image above:
1. Horizontal semicircular canal
2. Facial nerve
3. Posterior semicircular canal
4. Endolymphatic sac
5. Posterior fossa dura
6. Sigmoid sinus
  • Horizontal semicircular canal: Detects angular acceleration.
  • Facial nerve: Responsible for facial expression and taste sensation.
  • Posterior semicircular canal: Also involved in detecting angular acceleration.
  • Endolymphatic sac: Regulates endolymphatic fluid pressure and volume.
  • Posterior fossa dura: Outermost layer of the meninges in the posterior fossa.
  • Sigmoid sinus: Drains blood from the brain towards the heart.

Pathology and Pathophysiology

Endolymphatic sac surgery is primarily indicated in the treatment of Meniere's disease, believed to be related to an imbalance in endolymph production and absorption.

  • Meniere's Disease: Characterized by vertigo, hearing loss, tinnitus, and aural fullness.
  • Endolymphatic Hydrops: Excessive accumulation of endolymph in the inner ear.

Endolymphatic sac surgery aims to reduce endolymphatic pressure through decompression or diversion of fluid. It may involve exposing the sac by removing bone and dura, followed by shunt placement or sac decompression.

Otolaryngology Examination Questions

  1. Indications for Surgery: "What conditions indicate endolymphatic sac surgery, and what are the expected outcomes?"
  2. Surgical Approach: "Describe the surgical approach to the endolymphatic sac for decompression in Meniere's disease."
  3. Complications: "What are the potential complications of endolymphatic sac surgery?"
  4. Anatomical Considerations: "Discuss the anatomical structures at risk during endolymphatic sac surgery."