Schwartz operation is done in -
Indications of simple / cortical mastoidectomy (Schwartz operation)

Acute coalescent mastoiditis.
Incompletely resolved acute otitis media with reservoir sign.
Masked mastoiditis.
As a initial step to perform:


Endolymphatic sac surgery
Decompression of facial nerve
Translabyrinthine or retrolabyrinthine procedures for acoustic neuroma.
CSOM
Serous otitis media
Otosclerosis
Acute mastoiditis