The present article reports the clinical cases of the surgical intervention on 20 patients presenting with petrous bone cholesteatoma. We have identified several clinical variants of petrous bone cholesteatoma based on the results of multispiral computed tomography (MSCT) of the temporal bones and categorized them into the following types in accordance with the classification proposed by Moffat-Smith an M. Sanna for this pathological condition: supralabyrinthine (n=8), supralabyrinthine-apical (n=2), infralabyrinthine (n=3), infralabyrinthine-apical (n=5), massive (n=1), and massive - apical (n=1). The surgical sanation of petrous bone cholesteatoma was performed in all the 20 patients in the absence of the pronounced bone destruction in the walls of the temporal bone pyramid and of the subdural expansion of cholesteatoma. In all the cases, the trepanation cavity remained open till its complete epidermization. The follow up period was around 3 years in duration on the average. The post-surgical analysis of the clinical conditions of each of the 20 patients was performed with special reference to the surgical technique applied for the removal of petrous bone cholesteatoma and the final outcome of the radical treatment.

The recurrent cholesteatomic process is one of the main causes of the poor outcome of the surgical treatment in the patients with acquired cholesteatoma of the middle ear. The relapse can be due to the incomplete removal of the cholesteatomic matrix especially from the difficult to access for visual control during the surgical intervention parts of the anterior epitympanic space, medial sinuses of retrotympanum, deep-lying portions of hypotympanum, and retrofacial part of the mastoid cavity. One more cause behind the recurrent process is the retention of the conditions for the secondary retraction of the neotympanic membrane, The objective of the present study was the improvement of the surgical modalities for better visualization and sanation of the difficult to access anatomically complex parts of the middle ear under the eye control, the creation of the conditions for the additional ventilation of the tympanic cavity and the reduction of the risk of development of residual and/or recurrent cholesteatomas. To this effect, we undertook the analysis of the results of 438 primary and 226 secondary (revisional) surgical interventions on the patients presenting with chronic suppurative otitis media and concomitant cholesteatomas. The study has demonstrated that the cause of 14.6% of the cases of residual cholesteatoma was the incomplete removal of its matrix from the anterior epitympanic space, medial sinuses of retrotympanum, deep-lying portions of hypotympanum, and retrofacial part of the mastoid cavity. The proposed surgical strategies reduced the risk of development of residual cholesteatoma from 8.2% to 3.9%. The newly developed method for the additional ventilation of the tympanic cavity allowed the frequency of recurrent cholesteatoma to be decreased from 2.5% to 1.6%.