The floating mass transducer at the round window: direct transmission or bone conduction?

The round window placement of a floating mass transducer (FMT) is a new approach for coupling an implantable hearing system to the cochlea. We evaluated the vibration transfer to the cochlear fluids of an FMT placed at the round window (rwFMT) with special attention to the role of bone conduction. A posterior tympanotomy was performed on eleven ears of seven human whole head specimens. Several rwFMT setups were examined using laser Doppler vibrometry measurements at the stapes and the promontory. In three ears, the vibrations of a bone anchored hearing aid (BAHA) and an FMT fixed to the promontory (pFMT) were compared to explore the role of bone conduction. Vibration transmission to the measuring point at the stapes was best when the rwFMT was perpendicularly placed in the round window and underlayed with connective tissue. Fixation of the rwFMT to the round window exhibited significantly lower vibration transmission. Although measurable, bone conduction from the pFMT was much lower than that of the BAHA. Our results suggest that the rwFMT does not act as a small bone anchored hearing aid, but instead, acts as a direct vibratory stimulator of the round window membrane.

Factors improving the vibration transfer of the floating mass transducer at the round window

With the placement of a floating mass transducer (FMT) at the round window, a new approach of coupling an implantable hearing system to the cochlea has been introduced. The aim of the present experimental study is to examine the influence of different ways of FMT placement at the round window on the vibration energy transfer to the cochlea.

Intensity-modulated radiotherapy for a rendu-osler-weber disease patient with recurrent severe epistaxis: a case report

We present a case of a Rendu-Osler-Weber disease patient with recurrent life threatening epistaxis demanding multiple blood transfusions despite of repetitive endoscopic laser and electrocoagulations, endovascular embolisation, septodermoplasty, and long-term intranasal dressings. As alternative treatment modalities repeatedly failed and the patient became almost permanently dependent on nasal dressing, we performed a highly conformal intensity-modulated radiotherapy of the nasal cavity; a total dose of 50 Gy in 2 Gy single fractions was applied. The therapy was very well tolerated, no acute toxicities occurred. Two weeks after the last radiation dose had been applied, the nasal dressing could be removed without problems. Endoscopical control revealed an almost avascular white mucosa without any trace of bleeding spots; previously existing hemangiomas and crusts had disappeared. After a 1-year-follow up, the patient had no significant recurrent epistaxis.

Incidence of small lymph node metastases with evidence of extracapsular extension: clinical implications in patients with head and neck squamous cell carcinoma

Small lymph nodes (LN) show evidence of extracapsular extension (ECE) in a significant number of patients. This study was performed to determine the impact of ECE in LN 7 mm as compared with ECE in larger LN.

Primary tumors of the submandibular glands: a retrospective study based on 41 cases

We report our experience on the diagnostic approach, treatment, and follow-up of primary submandibular gland tumors. Retrospective review. Tertiary referral center. Forty-one adult patients, 22 male and 19 female, with primary submandibular gland tumors, 20 benign and 21 malignant. Age, gender, clinical findings, cyto- and histopathology, treatment and outcome were analyzed. Most tumors presented as a painless submandibular mass. Thirty three patients underwent a fine needle aspiration, the sensitivity, specificity and accuracy of which--in detecting malignant tumors--were 79%, 100% and 88%, respectively. Preoperative radiological imaging was performed in 30 cases. Patients with benign tumors were treated with surgery. Most malignant tumors were treated with a combined modality, including neck dissection and radiation therapy. Five patients developed a postoperative complication. Recurrent disease was encountered in 5 malignant tumors. The 2, 5 and 10 year disease-specific survival of patients with malignancy were 84%, 75% and 41%, respectively. The preoperative assessment of the nature of submandibular gland tumors remains challenging. Aggressive treatment of patients with malignant disease may help to avoid poor prognosis.

Benefits of low-frequency attenuation of baha® in single-sided sensorineural deafness

To investigate the effect of low-frequency attenuation of Bone-Anchored Hearing Aids (Bahas) in users with single-sided sensorineural deafness (SSD). The underlying notion is that low-frequency sounds up to approximately 1500 Hz reach the contralateral ear without significant attenuation and that Bahas tend to show more distortion at lower frequencies. Furthermore, to transmit low frequencies, higher moving masses are needed when compared with high frequencies.

Radiation dose optimization in pediatric temporal bone computed tomography: influence of tube tension on image contrast and image quality

The purpose of this experimental study was to investigate the effect of tube tension reduction on image contrast and image quality in pediatric temporal bone computed tomography (CT).

Surgery for the bone-anchored hearing aid

This review covers the surgery for the bone-anchored hearing aid (Baha(®)). PREOPERATIVE WORKUP: A review of the indications and preoperative diagnostics shows that best results are generally obtained in patients with conductive or mixed hearing loss rehabilitation when surgery is not applicable or has failed and in patients that suffer from single-sided deafness. An audiogram must confirm that the bone conduction hearing is within the inclusion criteria. A computed tomography scan is performed in cases of malformation to assure sufficient bone thickness at the site of screw implantation.

Influence of a totally open oval window on bone conduction in otosclerosis

The aim of this study was to evaluate changes in bone conduction thresholds before, during and after total stapedectomy.

Retrograde cochlear implantation in postmeningitic basal turn ossification

Postmeningitic basal turn ossification is a challenge for successful cochlear implantation despite the availability of sophisticated implants and advanced drill-out procedures. A less complex concept consisting of a cochleostomy near the apex with retrograde array insertion is evaluated clinically and experimentally with emphasis on imaging of intracochlear array morphology.

Therapy options and long-term results of sinonasal malignancies

Nasal and paranasal sinus malignancies are rare. The most common lesions are located in the nasal cavity and the maxillary sinus, although they also occur in the ethmoid, sphenoid and frontal sinuses. Treatment often combines surgery, radiotherapy and chemotherapy. Endoscopic surgical approaches are increasingly used in order to reduce the morbidity associated with standard open resection. The aim of our study was to analyse the long-term treatment results of sinonasal malignancies (SNM), with a special focus on surgical approaches.

A self-developed and constructed robot for minimally invasive cochlear implantation

Conclusion: A robot built specifically for stereotactic cochlear implantation provides equal or better accuracy levels together with a better integration into a clinical environment, when compared to existing approaches based on industrial robots. Objectives: To evaluate the technical accuracy of a robotic system developed specifically for lateral skull base surgery in an experimental setup reflecting the intended clinical application. The invasiveness of cochlear electrode implantation procedures may be reduced by replacing the traditional mastoidectomy with a small tunnel slightly larger in diameter than the electrode itself. Methods: The end-to-end accuracy of the robot system and associated image-guided procedure was evaluated on 15 temporal bones of whole head cadaver specimens. The main components of the procedure were as follows: reference screw placement, cone beam CT scan, computer-aided planning, pair-point matching of the surgical plan, robotic drilling of the direct access tunnel, and post-operative cone beam CT scan and accuracy assessment. Results: The mean accuracy at the target point (round window) was 0.56 ± 41 mm with an angular misalignment of 0.88 ± 0.41°. The procedural time of the registration process through the completion of the drilling procedure was 25 ± 11 min. The robot was fully operational in a clinical environment.

Laser Doppler vibrometric assessment of middle ear motion in Thiel-embalmed heads

Thiel-embalmed human whole head specimens represent an alternative model in middle ear research.

Outcome and patterns of failure after postoperative intensity modulated radiotherapy for locally advanced or high-risk oral cavity squamous cell carcinoma

Background To determine the outcome and patterns of failure in oral cavity cancer (OCC) patients after postoperative intensity modulated radiotherapy (IMRT) with concomitant systemic therapy. Methods All patients with locally advanced (AJCC stage III/IV) or high-risk OCC (AJCC stage II) who underwent postoperative IMRT at our institution between December 2006 and July 2010 were retrospectively analyzed. The primary endpoint was locoregional recurrence-free survival (LRRFS). Secondary endpoints included distant metastasis-free survival (DMFS), overall survival (OS), acute and late toxicities. Results Overall 53 patients were analyzed. Twenty-three patients (43%) underwent concomitant chemotherapy with cisplatin, two patients with carboplatin (4%) and four patients were treated with the monoclonal antibody cetuximab (8%). At a median follow-up of 2.3 (range, 1.1–4.6) years the 3-year LRRFS, DMFS and OS estimates were 79%, 90%, and 73% respectively. Twelve patients experienced a locoregional recurrence. Eight patients, 5 of which had both a flap reconstruction and extracapsular extension (ECE), showed an unusual multifocal pattern of recurrence. Ten locoregional recurrences occurred marginally or outside of the high-risk target volumes. Acute toxicity grades of 2 (27%) and 3 (66%) and late toxicity grades of 2 (34%) and 3 (11%) were observed. Conclusion LRRFS after postoperative IMRT is satisfying and toxicity is acceptable. The majority of locoregional recurrences occurred marginally or outside of the high-risk target volumes. Improvement of high-risk target volume definition especially in patients with flap reconstruction and ECE might transfer into better locoregional control.

Diagnosis and treatment outcomes for patients with lymphoma of the parotid gland

Lymphoma of the parotid gland (LPG) is a rare disease. Clinical diagnosis is difficult, due to a lack of specific symptoms and findings. The aim of this study is to evaluate the diagnostic workup based on the analysis of our cases of LPG and to present the stage-dependent treatment outcome.