[Decompression procedures on the peripheral pneumatic system of the ear. IV. Conservative mastoidectomies (corticotomy, superficial mastoidectomy and partial mastoidectomy)].

According to segmental form of pneumatic otic system 3 steps forms of mastoidectomy was developed. The new aspect of this surgery is the preservation of the apical part of pneumatic segment system, which serve for the better drainage during the acute phase of mastoiditis. It like a sieve assure the successful drainage and ventilation as well as drug instillation. 20 years experience of author make this procedure safe for recommendation. The rate of recurrencies is lowered, and the problem of "great postoperative cavity" was solved.