[Are titanium implants superior to gold implants in the tympanic cavity?]

Passive and active middle ear implants

Besides eradication of chronic middle ear disease, the reconstruction of the sound conduction apparatus is a major goal of modern ear microsurgery. The material of choice in cases of partial ossicular replacement prosthesis is the autogenous ossicle. In the event of more extensive destruction of the ossicular chain diverse alloplastic materials, e.g. metals, ceramics, plastics or composits are used for total reconstruction. Their specialised role in conducting sound energy within a half-open implant bed sets high demands on the biocompatibility as well as the acoustic-mechanic properties of the prosthesis. Recently, sophisticated titanium middle ear implants allowing individual adaptation to anatomical variations are widely used for this procedure. However, despite modern developments, hearing restoration with passive implants often faces its limitations due to tubal-middle-ear dysfunction. Here, implantable hearing aids, successfully used in cases of sensorineural hearing loss, offer a promising alternative. This article reviews the actual state of affairs of passive and active middle ear implants.

[Treatment of chronic tube dysfunction. Use of the tube conductor]

BACKGROUND

Chronic tube dysfunction plays a major part in the development of chronic otitis media. Owing to the complex structure of the Eustachian tube, the development of successful therapeutic approaches to the treatment of tube function disorders is still difficult even today. The application of a gold tube wire (tube conductor) was reported in 1991, but no studies have yet been performed on the postoperative success rates achieved with tube conductors.

MATERIAL AND METHODS

In a retrospective study, the data relating to 125 patients who were operated on from 1996 to 1999 for treatment of different forms of chronic otitis media and also underwent transtympanic tube conductor implantation to improve tube ventilation disorder were evaluated. Data on pre- and postoperative tube function were available for 96 patients after a mean follow-up period of 18 months.

RESULTS

All tube implantations were achieved without complications. Tube function normalized in 8 patients (8.3%), while the tube ventilation disorder remained unaffected in 88 patients (91.7%). A total of 23 (18.4%) tube conductors have so far been removed. The reasons for removal include persistent tube ventilation disorder, dislocation of the tube conductor in 7 patients (5.6%) and granulation around the tube wire in 7 cases (5.6%).

CONCLUSIONS

The chronic tube ventilation disorder was improved by implantation of a tube conductor in only 8.3% of the patient population investigated. We are therefore of the opinion that this is not a suitable treatment for chronic tube ventilation disorders. The development of new, effective therapeutic approaches to the treatment of chronic tube ventilation disorders remains a priority.