[Pathogenesis and prevention of recurrent cholesteatoma following closed tympanoplasty].
The use of the closed tympanoplasty in the treatment of cholesteatoma has been abandoned by many surgeons in the last years. In contrast, as well as other authors we have increasingly limited the use of open techniques. Our attitude towards the closed tympanoplasty is strictly connected with an accurate prevention strategy of recurrent cholesteatoma. The recurrent cholesteatoma takes origin from two following mechanism: 1--the residual cholesteatoma which exteriorizes towards the external auditory canal; 2--the new immigration of the skin into the middle ear through a new perforation or depending on a retraction pocket. The incidence of recurrent cholesteatoma due to the first cause may be considerably reduced by: a--complete eradication of disease during exeresis (complete removal of structures in contact with the cholesteatoma matrix); b--early detection and removal of residual cholesteatoma by an almost planned second look (staged tympanoplasty). In order to prevent new epithelial immigration into the middle ear it is necessary: a--to reconstruct a new barrier between skin and mucous lining [repair of the attic wall, reconstruction of the tympanic membrane by using xenografts (Parmatymp)]; b--to permit the drainage and aeration of the new tympanic cavity at the level of the bony Eustachian tube including the isthmus (performing, if necessary, the tubotomy and/or tuboplasty techniques). The same must be obtained at the level of the tympanic isthmus by enlargement of the epitympanic recesses in order to create a tunnel over the new ossicular chain and by a posterior tympanotomy in order to create a tunnel under the ossicular chain. The use of silastic sheeting is extremely important in order to allow a correct regeneration of the new mucous lining and an efficient drainage-aeration function into the new middle ear cavity (from the mastoid to the tubal isthmus).