Biofilm formation on bone-anchored hearing aids

AbstractObjective:To investigate microbiological biofilm contamination of retrieved bone-anchored hearing aids.Materials and methods:Nine failed, retrieved bone-anchored hearing aids and 16 internal screws were examined by scanning electron microscopy. A fixture from a failing implant, which had been removed and disassembled under aseptic conditions, was cultured. Finally, an internal screw from a new, unimplanted fixture was examined by scanning electron microscopy.Results:Debris was seen on the fixture and abutment of all bone-anchored hearing aids, and on the heads of the 16 internal screws. On eight screws, biofilm extended down the shaft to the threads, where it was several micrometres thick. Culture of a failing fixture yielded staphylococcus. The new, unimplanted fixture internal screw showed evidence of scratching and metallic debris on the threads, which may interfere with close fitting of the screw and subsequently facilitate microleakage.Conclusion:There may be a link between internal microbial contamination and failure of bone-anchored hearing aids.</jats:sec

Temporal bone verrucous carcinoma: outcomes and treatment controversy

Verrucous carcinoma is a rare tumor that presents in the head and neck with the most common sites being the oral cavity and larynx. Fourteen cases of verrucous carcinoma of the temporal bone have been described in literature; this study aims to examine treatment outcomes and discuss the controversy surrounding postoperative radiation. The study design included a literature review along with individual case report in the setting of a tertiary care medical center. Outcome analysis of all cases of verrucous carcinoma of the temporal bone, which are documented in the English literature, and presentation of a single patient report including gross, histologic and radiologic analyses were performed. The longest recorded survival for verrucous carcinoma of the temporal bone occurs in patients treated with surgery alone. Poorer outcomes for patients treated with adjuvant (chemo)radiation may be due to more advanced stage of disease at the time of treatment. Early reports of radiation leading to tumor dedifferentiation or early recurrence are not supported by more recent studies. Whether adjuvant radiation therapy is indicated in verrucous carcinoma of the temporal bone remains controversial

Bone-anchored hearing aid surgery in older adults: implant loss and skin reactions.

Contains fulltext : 80763.pdf (publisher's version ) (Open Access)OBJECTIVES: We evaluated the clinical outcome measures of fixture loss and skin reactions in older-adult users of percutaneous bone-anchored hearing aids (BAHAs). METHODS: We performed a retrospective analysis of 224 older adults (at least 60 years of age) who underwent implantation of 248 implants with the simplified Nijmegen surgical technique between January 1995 and May 2007. RESULTS: During a mean follow-up of 39 months (range, 0 to 144 months), 16 of the 248 implants were lost (6.5%). The causes were failed osseointegration in 9 cases, trauma in 6 cases, and implant loss in irradiated bone in 1 case. There were no losses due to infection. Implant loss was not significantly correlated with age. In 40 implants (16.9%), severe skin reactions of Holgers grade 2 or more were observed. Skin revision surgery was performed around 6 implants (2.4%). None of the patients had an 8.5-mm abutment to overcome severe skin reactions. CONCLUSIONS: The outcome of BAHA surgery in older adults was favorable. The rate of implant loss was comparable with that in the overall population of BAHA recipients. There were low risks of severe skin reactions or developing thick skin around the implant

Comparison on intracochlear disturbances between drilling a manual and robotic cochleostomy

In hearing preservation cochlear implantation (HPCI), it is considered that minimizing disturbances in hearing organ are likely to reduce trauma and protection of the underlying endosteal membrane of the cochlea is an important factor in cochleostomy formation. The robotic micro-drill system tested in this paper is the first example of an autonomous surgical drill successfully producing a cochleostomy, which keeps the underlying endosteal membrane intact. This study compares induced vibrations within the cochlea during formation of the cochleostomy between using the robotic micro-drill and conventional manual drilling. The vibration of the endosteal membrane is measured using a Microscope Scanning Vibrometer (MSV) at a third window, produced in the cochlea. Results show that the highest velocity amplitude measured was associated with the manual drilling. The robotic micro-drill produced only about 1% of the peak velocity amplitude seen in manual drilling and exhibited much more uniform behaviour, while keeping the underlying membrane intact. The technique applied when using the robotic drill could be a major step in reducing the trauma to the cochlea, by reducing disturbance levels