Akute Komplikationen in der Mittelohrchirurgie

Surgery of the ear and the lateral skull base: pitfalls and complications

Surgery of the ear and the lateral skull base is a fascinating, yet challenging field in otorhinolaryngology. A thorough knowledge of the associated complications and pitfalls is indispensable for the surgeon, not only to provide the best possible care to his patients, but also to further improve his surgical skills. Following a summary about general aspects in pre-, intra-and postoperative care of patients with disorders of the ear/lateral skull base, this article covers the most common pitfalls and complications in stapes surgery, cochlear implantation and surgery of vestibular schwannomas and jugulotympanal paragangliomas. Based on these exemplary procedures, basic "dos and don'ts" of skull base surgery are explained, which the reader can easily transfer to other disorders. Special emphasis is laid on functional aspects, such as hearing, balance and facial nerve function. Furthermore, the topics of infection, bleeding, skull base defects, quality of life and indication for revision surgery are discussed. An open communication about complications and pitfalls in ear/lateral skull base surgery among surgeons is a prerequisite for the further advancement of this fascinating field in ENT surgery. This article is meant to be a contribution to this process.

[Results of stapedotomies performed under general anesthesia]

INTRODUCTION

It is recommended that a stapedotomy be performed under local anaesthesia to enable intraoperative monitoring of hearing and vestibular function. In contrast, we prefer to carry out stapedotomies under general anesthesia. The aim of this study was to investigate whether this practice has an adverse effect on hearing results.

PATIENTS AND METHODS

All stapedotomies performed in our department between May 2003 and February 2012 were included in the analysis. Revision surgery was excluded. All interventions were performed under general anesthesia with an endotracheal tube by the same surgeon using the same technique. Pure tone and speech audiometry, acoustic reflex testing and Schüller radiology were performed preoperatively. Follow-up examinations (pure tone and speech audiometry) took place 4-6 weeks following surgery.

RESULTS

A total of 262 stapedotomies were carried out on 228 patients. Follow-up examinations could not be performed on six patients. Of the remaining 256 cases, closure of the air-bone gap to less than 10 dB was achieved in 220 patients (86%) and in 29 patients (11%) it was closed to less than 20 dB. Conductive hearing loss persisted in seven cases (3%). A mild sensorineural hearing loss with complete closure of the air-bone gap was experienced by two patients (0.8%). There was no instance of postoperative deafness.

CONCLUSIONS

Performing stapedotomies under general rather than local anesthesia has no adverse effects on audiological results.

[CO2-laser-assisted de-epithelialization of perforation margins of persistent tympanic membrane perforations. An alternative to conventional surgical procedures]

INTRODUCTION

The standard treatment of persistent eardrum perforation is conventional surgical closure using myringoplasty or a tympanoplasty type I. In this study the valence of a modified, CO(2)-laser-assisted de-epithelialization of perforation margins was investigated.

MATERIAL AND METHODS

A total of 44 patients with mesotympanal eardrum perforation (diameter 1-5 mm) were included in a partially retrospective and partially prospective study. The genesis of the eardrum perforations was partially traumatic or the eardrum did not heal after spontaneous perforation caused by an acute otitis media or after surgery. The procedure was performed under topical anaesthesia. Focussed, adjacent, single CO(2) laser pulses (1 watt, 0.05 s) were applied with the laser otoscope Otoscan (Lumenis, Yokneam, Israel) along the edge of the perforation until complete de-epithelialization. This was done to stimulate growth. Closure of eardrum perforation was monitored using an ear microscope and if this treatment was not successful after three attempts conventional surgical therapy was suggested.

RESULTS

Complete eardrum closure occurred in 27 cases (61%), 17 patients (39%) had a residual perforation, of which 9 experienced a significant reduction of the perforation. There were no complications during and after the treatment.

CONCLUSION

A closure rate of at least 61% (27/44) can be expected with a CO(2)-laser-assisted de-epithelialization of the perforation margins. This procedure can be performed under topical anaesthesia and is an economic, painless and facile alternative to conventional surgical treatment.

[Significance of computed tomography evaluation before revision stapes surgery]

BACKGROUND

Stapedectomy and, more recently, stapedotomy have been widely accepted as the primary surgical techniques to improve conductive hearing in patients suffering from otosclerosis. Unsuccessful outcomes are infrequent, but revision surgery may become necessary. We have analyzed the value of computed tomography (CT) scanning following unsuccessful stapes surgery.

PATIENTS AND METHODS

In a total of 37 CT scans, the depth of insertion, angle between prosthesis and footplate, location of prosthesis within the oval niche, visibility of the prosthesis, dehiscence of the superior semicircular canal, and extent of otospongiotic foci were evaluated and compared with the audiometric results.

RESULTS

There was no significant correlation between CT parameters and audiologic results, except for patients with cochlear otosclerosis or lateral dislocation of the piston. One previously unknown dehiscence of the superior semicircular canal was diagnosed. Otospongiotic foci were seen in 13 ears (35%).

CONCLUSION

Displacements of the stapes piston and rare causes for an insufficient result, such as a dehiscence of the superior semicircular canal, can be diagnosed accurately by CT. However, correlation between the audiologic results and the findings on CT scans was possible in only a few cases. Nevertheless, CT scans provide additional information for surgical planning in revision stapes surgery and may become increasingly important to reduce unanticipated intraoperative risks; they may even guide the surgeon not to perform unnecessary revision surgeries.