Meniere's Disease Part 4 - Surgical Management

👂 Meniere's Disease - Surgical Management

🎯 Aims of Surgery

1️⃣ To abolish or alter the function of the labyrinth

2️⃣ To modify the underlying pathophysiology

What are the Factors Determining the Choice of Surgery in Meniere's disease?

📋 Classification of Surgical Options

1- Conservative Procedures (Hearing Preserved)

• Endolymphatic sac decompression

  • Portmann's technique
  • Subarachnoid shunt (House)
  • Mastoid shunt (Arenberg, Morrison, Shea)
  • Modification of Hasegawa and Naito
  • Decompression without opening the sac (Shambaugh)
  • Paparella and Hanson technique

• Sacculotomy

  • Fick's procedure
  • Cody's tack procedure

• Cochleosacculotomy

2- Partially Destructive Procedures (Hearing Preserved)

• Vestibular nerve section

  • Middle fossa approach
  • Retrosigmoid approach
  • Retrolabyrinthine approach

• Ultrasonic irradiation of the labyrinth

• Cryosurgery

3- Destructive Procedures (Hearing Not Preserved)

• Labyrinthectomy

  • Transcanal approach
  • Transmastoid approach

• Destruction of the Scarpa's ganglion

• Translabyrinthine section of the vestibular nerve

🧠 Anatomy of the Endolymphatic Sac

The endolymphatic sac is a pear shaped structure located in the thickened portion of the posterior fossa dura, medial to the sigmoid sinus and inferior to the posterior semicircular canal.

What are the Boundaries of the Endolymphatic Sac?

How will you identify the Endolymphatic Sac during surgery?

What is Donaldson's Line? What is the relation of Endolymphatic Sac to it?

🔍 Endolymphatic Sac Decompression (Portmann's Technique)

⭐ This is the base technique. All the modifications follow the same steps and differ only in the final step.

Steps

1️⃣ Simple cortical mastoidectomy

2️⃣ Identification of the four landmarks:

3️⃣ Skeletonization of the area medial to the sigmoid sinus and the mastoid segment of the facial nerve

4️⃣ Exposure of the posterior fossa dura and identification of the endolymphatic sac

5️⃣ The dura is gently depressed away from the overlying bone of the posterior semicircular canal, noting the spot at which the dura mater is fixed to the bone of the canal by the duct

6️⃣ Incision on the outer surface of the dura, from behind forward

7️⃣ Gel foam placed in the depth of the operating field, a drain placed, and the wound closed

What is the Subarachnoid Shunt modification proposed to Endolymphatic sac decompression by House?

What is the Mastoid Shunt modification proposed to Endolymphatic sac decompression by Arenberg?

What is the Mastoid Shunt modification proposed to Endolymphatic sac decompression by Morrison?

What is the Mastoid Shunt modification proposed to Endolymphatic sac decompression by Shea?

What is the modification proposed to Endolymphatic sac decompression by Hasegawa and Naito?

What is Paparella and Hanson technique?

What are the problems encountered during Endolymphatic Sac Surgery? How will you manage them?

⚠️ Complications of Endolymphatic Sac Surgery

• Sensorineural deafness, if the posterior semicircular canal is breached
• Bleeding
• CSF fistula
• Meningitis

⭐ Results of Endolymphatic Sac Surgery

🔍 Sacculotomy

🎯 Aim

Decompression of the endolymphatic system by puncturing the saccule, through the oval window.

Common Steps

1- Transcanal approach, raising the tympanomeatal flap

2- Visualization of the stapes footplate

3- Fenestration through the footplate

What is Fick's Technique?

What is Cody's Tack Technique?

⚠️ Complications

• Recurrence of vertigo
• Post-operative hearing loss

🔍 Cochleosacculotomy

🎯 Aim

A penetrating injury to the cochlear duct with an associated fracture of the osseous spiral lamina, creating a permanent fistula of the cochlear duct.

Procedure

Performed under local anaesthesia.

1️⃣ Transcanal approach, elevating the tympanomeatal flap

2️⃣ Exposure of the oval window and round window

3️⃣ The round window niche is removed with a small cutting bur, to fully visualize the round window membrane

4️⃣ A 3 mm right angled pick is introduced through the round window and passed to a depth of about 3 mm

👉 This passage carries through the cochlear partition, causing fracture and disruption of the osseous spiral lamina and the cochlear duct

5️⃣ The tip of the pick comes to lie at the centre of the oval window, with rupture of the dilated saccule

⭐ The cochlear duct is thus punctured and drained into the perilymph, creating an otic-periotic shunt.

⚠️ Complications

• Recurrence of vertigo
• Post-operative hearing loss

⭐ Because of these complications, sacculotomy and cochleosacculotomy are not commonly performed now.

🔍 Vestibular Nerve Section

Selective sectioning of the vestibular nerve, which is responsible for the vertigo, while preserving the cochlear nerve and hence the hearing.

Three approaches:

1️⃣ Middle fossa approach

2️⃣ Retrosigmoid approach

3️⃣ Retrolabyrinthine approach

What are the steps of Middle fossa approach to Vestibular Nerve Section?

What are the advantages and disadvantages of Middle fossa approach to Vestibular Nerve Section?

What are the steps of Retrosigmoid approach to Vestibular Nerve Section?

What are the advantages and disadvantages of Retrosigmoid approach to Vestibular Nerve Section?

What are the steps of Retrolabyrinthine approach to Vestibular Nerve Section?

What are the advantages and disadvantages of Retrolabyrinthine approach to Vestibular Nerve Section?

🔍 Ultrasonic Irradiation of the Labyrinth

A selective labyrinthectomy, in which the semicircular canals are destroyed while the organ of Corti is preserved, allowing preservation of hearing.

Procedure

• A probe delivers ultrasonic irradiation to the round window through a tympanotomy incision

🧠 Mechanism

The ultrasonic radiation is absorbed and heat is given off, dissipating quickly through the inner ear fluids.

👉 Thermal and mechanical injury causes selective injury to the membranous labyrinth, controlling vertigo while preserving cochlear function.

🔍 Cryosurgery

• A temperature of minus 160 degrees Celsius is applied to the lateral semicircular canal
• Controlled freezing causes vestibular hair cell and nerve injury, producing unilateral vestibular hypofunction

👉 Helps control recurrent vertigo.

⚠️ Limitation: Hearing preservation is unpredictable, which is why this approach is not popular.

🔍 Labyrinthectomy

Complete destruction of the membranous labyrinth, destroying both cochlear and vestibular function.

📌 Indication

👉 Only when the cochlear function is no longer serviceable

Two approaches:

A- Transcanal Approach

What are the steps of Transcanal Approach to Labyrinthectomy?

❌ Limitations

• Poor access to the posterior semicircular canal, which lies medial to the facial nerve, so complete ablation may not be achieved
• Technically more difficult
• Small operative field

B- Transmastoid Approach

What are the steps of Transmastoid Approach to Labyrinthectomy?

✅ Advantages

• Very good direct visualization of the vestibular end organs
• Excellent exposure and operative field

🔍 Destruction of the Scarpa's Ganglion

📌 The Scarpa's ganglion is also known as the vestibular ganglion.

🎯 Aim

To abolish abnormal vestibular afference by destroying the vestibular ganglion, thereby relieving recurrent vertigo.

What is the mechanism of action of destruction of Scarpa's ganglion in treatment of Meniere's disease?

⚠️ Complications

• Sensorineural hearing loss
• Facial nerve injury
• Persistent imbalance

🔍 Translabyrinthine Section of the Vestibular Nerve

Procedure

• A translabyrinthine approach through the mastoid and then through the labyrinth
• The internal auditory canal is exposed
• The vestibular nerve is divided

⚠️ As the labyrinth is sacrificed, there is no residual hearing in the operated ear.

⭐ This is the difference from the middle fossa, retrosigmoid and retrolabyrinthine approaches, in which hearing is preserved.

What is the indication of Translabyrinthine Section of the Vestibular Nerve?

🧠 Viva Pearls

• The aims of surgery are to abolish or alter labyrinthine function and modify the underlying pathophysiology.
• Surgical options are classified as conservative, partially destructive and destructive.
• The basic endolymphatic sac decompression technique was described by Portmann.
• Opening the posterior semicircular canal during sac surgery causes total deafness.
• Endolymphatic sac surgery relieves vertigo in 80 to 90% of patients.
• Sacculotomy decompresses the endolymphatic system by puncturing the saccule through the oval window.
• Cochleosacculotomy creates an otic-periotic shunt.
• Vestibular nerve section preserves hearing by sparing the cochlear nerve.
• Ultrasonic irradiation destroys the semicircular canals while preserving the organ of Corti.
• Cryosurgery uses a temperature of minus 160 degrees Celsius applied to the lateral semicircular canal.
• Labyrinthectomy is indicated only when hearing is non-serviceable.
• Scarpa's ganglion is the vestibular ganglion.
• Translabyrinthine vestibular nerve section leaves no residual hearing in the operated ear.

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