Which of the following surgery is known as Schwaz operation?

Coical mastoidectomy, known as simple or complete mastoidectomy or Schwaz operation, is complete exenteration of all accessible mastoid air cells and conveing them into single cavity. Posterior meatal wall is left intact. Middle ear structures are not disturbed. Indications: 1. Acute coalescent mastoiditis 2. Incompletely resolved acute otitis media with reservoir sign 3. Masked mastoiditis 4. As an initial step to perform, Endolymphatic sac surgery Decompression facial nerve Translabyrinthine or retrolabyrinthine procedures for acoustic neuroma