Jan Helms

Clinical experience with the Vibrant Soundbridge implant device.

Objective To evaluate the full degree and range of benefits provided by the Vibrant Soundbridge (VSB; Symphonix Devices, Inc., San Jose, CA, U.S.A.) and analyze pre-and postoperative results of audiologic tests. Study Design Single-subject study with each subject serving as his or her own control. Setting Multicenter clinical study conducted at 10 centers in Europe. Patients 47 patients who met the selection criteria for participation in the study. Interventions Implantation of the VSB direct-drive middle ear hearing device. Main Outcome Measures Average change in unaided thresholds with the patient wearing headphones at each frequency pre-and postsurgery was measured. A mean threshold change less than 5 dB across all frequencies was considered clinically nonsignificant. Results 47 patients had successful surgery for implantation and fitting with the VSB device. Conclusion The VSB is a new middle ear implant device that can be used safely in the treatment of patients with moderate to severe sensorineural hearing loss.

Acoustic neuroma surgery as an interdisciplinary approach: a neurosurgical series of 508 patients

OBJECTIVES To evaluate an interdisciplinary concept (neurosurgery/ear, nose, and throat (ENT)) of treating acoustic neuromas with extrameatal extension via the retromastoidal approach. To analyse whether monitoring both facial nerve EMG and BAEP improved the functional outcome in acoustic neuroma surgery. METHODS In a series of 508 patients consecutively operated on over a period of 7 years, functional outcome of the facial nerve was evaluated according to the House/Brackmann scale and hearing preservation was classified using the Gardner/Robertson system. RESULTS Facial monitoring (396 of 508 operations) and continuous BAEP recording (229 of 399 cases with preserved hearing preoperatively) were performed routinely. With intraoperative monitoring, the rate of excellent/good facial nerve function (House/Brackmann I-II) was 88.7%. Good functional hearing (Gardner/Robertson 1–3) was preserved in 39.8%. CONCLUSION Acoustic neuroma surgery via a retrosigmoidal approach is a safe and effective treatment for tumours with extrameatal extension. Functional results can be substantially improved by intraoperative monitoring. The interdisciplinary concept of surgery performed by ENT and neurosurgeons was particularly convincing as each pathoanatomical phase of the operation is performed by a surgeon best acquainted with the regional specialties.

Speech reception thresholds obtained in a symmetrical four-loudspeaker arrangement from bilateral users of MED-EL cochlear implants.

Objective The purpose of the study was to investigate speech reception in noise in subjects who had undergone bilateral implantation with multichannel cochlear implants. Methods Nine adults with bilateral MED-EL implants were included in the study. The subjects were tested using both implants and the better implant only. Tests were performed in a symmetrical setup, which ideally eliminates any head shadow effect. Speech tests included sentences in quiet and at various signal-to-noise ratios. From the results, the gain in signal-to-noise ratios at the speech reception threshold was determined. Results All subjects showed a substantial gain in signal-to-noise ratios of approximately 4 dB on average. In addition, the gain in signal-to-noise ratios was essentially stable for as long as 4.4 years. Conclusions The results indicate that bilateral cochlear implant users are able to binaurally process speech.

Meningitis following Cochlear Implantation: Pathomechanisms, Clinical Symptoms, Conservative and Surgical Treatments

Pneumococcal otogenic meningitis is a rare postsurgical complication that can develop following stapedectomy or after cochlear implantation. The bacterial infection can be fatal in some instances. A recent increase in the incidence of otogenic meningitis among cochlear implant wearers is of concern. The majority of meningitis cases are associated with a 2-component electrode manufactured by one cochlear implant company. The device with the added ‘positioner’ component has been withdrawn from the market (FDA Public Health Web Notification: Cochlear Implant Recipients may be at Greater Risk for Meningitis, Updated: August 29, 2002, www.fda.gov/cdrh/safety/cochlear.html). Not all cases have been subsequent to otitis media and symptoms have developed from less than 24 h up to a few years after implantation. The purpose of this paper is to review and discuss the pathogenesis, pathology/bacteriology and to elaborate on some clinical features of otogenic meningitis in implanted children and adults. Essential aspects of surgery, electrode design, and cochleostomy seal are discussed. Conclusions are drawn from the available data and recommendations are made for good practice in cochlear implantation and follow-up.

Quantitative Parameters of Intraoperative Electromyography Predict Facial Nerve Outcomes for Vestibular Schwannoma Surgery

OBJECTIVE Facial nerve monitoring is an established method that is routinely used during cerebellopontine angle tumor surgery. The aim of this study was to determine quantitative electromyographic (EMG) parameters that were predictive of facial nerve outcomes. METHODS In 137 patients with intra-/extrameatal vestibular schwannomas, the most proximal (the exit from the brainstem) and distal (the fundus of the internal auditory canal) parts of the facial nerve were stimulated after total tumor removal. A quantitative analysis of absolute values and ratios (proximal/distal) of evoked EMG parameters (amplitude, latency, and duration) was performed, and parameters were correlated with postoperative (1 and 6 wk and 6 mo) facial nerve function (FNF). RESULTS Absolute values of EMG amplitudes were statistically correlated with FNF (P < 0.05). Amplitude ratios (proximal/distal) demonstrated an even greater predictive power. The risk of exhibiting facial palsy 6 months after surgery increased from 1.6% (amplitude ratio of >0.8) to 75% (ratio of <0.1). For EMG latencies, only the ratios revealed a significant correlation with FNF. The latency ratio-dependent risk of facial palsy after 6 months increased from 2.9% (ratio of <1.05) to 33% (ratio of >1.35). The durations of the muscle responses were not significantly correlated with clinical outcomes. CONCLUSION The predictive power of the amplitudes and latencies of electrically evoked muscle responses could be improved by calculating proximal/distal ratios. The proximal/distal amplitude ratio proved to be the most powerful parameter for intraoperative assessment of postoperative FNF.

Combined Intra-Operative Monitoring of Hearing by Means of Auditory Brainstem Responses (ABR) and Transtympanic Electrocochleography (ECochG) During Surgery of Intra- and Extrameatal Acoustic Neurinomas

Summary.Summary.Background: Although being established as a standard procedure in intra-operative monitoring in acoustic neurinoma surgery, auditory brainstem responses (ABR) represent a far-field technique bearing some technical limitations. This prospective study was designed to evaluate electrocochleography (ECochG) as a supplementary tool for hearing preservation.Method: 84 patients with unilateral intra-/extrameatal acoustic neurinomas (extrameatal diameter: 5–55 mm) preserving serviceable hearing, were operated on using a combined (neuro-/otosurgical) suboccipital approach. ECochG was recorded simultaneously to ABR following transtympanic insertion of a steel needle electrode into the promontory under otoscopic view.Findings: Serviceable hearing (Class 1–3 according to Gardner/Robertson) was preserved in 43 out of 84 patients (51.2%), of whom 40 showed both ECochG and ABR being preserved. All 24 patients with loss of both modalities became deaf. Hearing preservation was observed in 4 out of 12 patients with preserved ECochG but loss of ABR (waves III–V). The reverse was observed in 2 cases with postoperative deafness. While both ECochG and ABR amplitudes were significantly correlated with pre- and postoperative hearing, latencies of ECochG summating (SP) and action potential (AP) proved to be more reliable indicators for preserved hearing than ABR (peak I/III/V) latencies. The predictive value of baseline ABR amplitudes for postoperative hearing, however, was superior to ECochG parameters. Only in large neurinomas (extrameatal diameter: >2 cm) tumour size was found to be a significant predictor for the preservation of hearing. Apart from three cases with postoperative otoliquorrhea and one further case presenting with local bleeding within the external acoustic meatus, no side effects were observed.Conclusions: In combination with ABR monitoring, ECochG proved to be a useful supplementary tool for hearing preservation in acoustic neurinoma surgery. It is particularly helpful during electrocautery and drilling, since no averaging is required. Special applications are: (1) small tumours with good serviceable hearing; (2) and/or a large intrameatal portion; (3) cases with lost or endangered contralateral hearing (e.g. bilateral acoustic neurinomas), when the preservation of poor or even non-functional hearing is desirable.

Ionomer-based bone substitute in otologic surgery

SummaryDuring post-set hardening the self-curing bone substitute Ionocem develops a solid bond with the adjacent bony tissue, leaving no empty spaces. The fully matured material can be fixed to bone with freshly mixed cement or it may be used as a blank, e.g. an ossicular implant (Ionos ossicle). After insertion of 945 alloplastic middle ear prostheses over a period of 4.5 years, the take-rate was 94%. In some patients revision surgery became necessary, in 50% of cases because of prosthesis dislocation. A granular version of the cement (Ionogran) was implanted in 46 ears for obliteration of mastoid cavities and showed complete mucosal overgrowth within a maximal period of 3 months. Posterior canal wall reconstruction with the self-curing bone substitute was done in 74 patients, with revisions required in 12 cases because of persistent epithelial deficits in the external ear canal or epitympanic retraction. Overall results showed that the ionomer-based cement was a useful substitute for bone in reconstructive otologic surgery.

Induction chemotherapy with paclitaxel and cisplatin and CT-based 3D radiotherapy in patients with advanced laryngeal and hypopharyngeal carcinomas--a possibility for organ preservation.

BACKGROUND To evaluate the effect of paclitaxel/cisplatin induction chemotherapy (ICHT) and CT-based radiotherapy (RT) on larynx preservation, tumor control, and survival in patients with larynx/hypopharynx carcinoma eligible for total laryngectomy (TL) or TL plus partial pharyngectomy (TLPP). PATIENTS AND METHODS Fifty patients eligible for TL or TLPP were enrolled onto a prospective study and treated with ICHT (200 mg/m(2) paclitaxel, 100 mg/m(2) cisplatin; day 1, 22). In patients with complete or partial tumor response RT (69.9 Gy in 5.5 weeks at the gross tumor, 50.4 Gy in the lymphatic drainage; single dose: 1.8 Gy, concomitant boost: 1.5 Gy) was applied. Non-responders had TL/TLPP and RT with total doses adapted to the radicality of tumor resection (56-70 Gy). RESULTS The response rate to ICHT was 88% (10% complete, 78% partial response). At a median follow-up period of 25 months the larynx preservation rate was 84%. The 2-year local-regional control rate was 91% and the 2-year overall survival rate was 72.3%. The 3-year estimate to survive with functional larynx is 60%. CONCLUSION In a large portion of patients eligible for TL or TLPP the larynx was preserved by paclitaxel/cisplatin ICHT and 3D RT.

Management of anterior epitympanic cholesteatoma: expectations after epitympanic approach and canal wall reconstruction.

Background The epitympanic approach to cholesteatoma provides excellent access to the anterior epitympanic space. When it is combined with reconstruction of the scutum, it is tempting to propose that the approach may offer the patient the advantage of both canal wall up and canal wall down techniques and the disadvantages of neither. In theory, then, the incidence of residual/recurrent cholesteatoma should be no greater than that for canal wall down surgery, and the need for a second look often associated with the canal wall up procedure should be less compelling. However, validation of this theory is lacking. Objective To test this theory, we sought to establish the incidence of recidivism in patients undergoing cholesteatoma removal via the epitympanic approach followed by canal wall reconstruction, to identify anatomic factors predisposing to persistent disease, and to identify technical features or problems associated with recurrent cholesteatoma. Study Design A retrospective case series. Setting A tertiary referral center. Patients Fifty-four adults and 11 children with extensive cholesteatoma involving but not limited to the anterior epitympanic space. Intervention All patents underwent removal of cholesteatoma via the epitympanic approach with canal wall reconstruction followed by reexploration 1 year later. Results Recurrent/residual disease was observed in 6 adults (11%) and 5 of 11 children (45%). The anterior epitympanic space harbored cholesteatoma in 100% of adults and 80% of children with recurrent disease. Conclusion The epitympanic approach does not eliminate the need for reexploration in cases of extensive cholesteatoma involving the anterior epitympanic space. The anterior epitympanic space is highly likely to harbor residual disease. Features of the canal wall reconstruction can be identified that predispose to recurrence. Long-term follow-up and close surveillance are mandatory, especially in children.

Technical developments in intra-operative monitoring for the preservation of cranial motor nerves and hearing in skull base surgery

Although EMG recordings from mimic muscles have become the standard for intra-operative facial nerve monitoring, few data are available concerning other motor cranial nerves (MCN). Auditory brainstem responses (ABR) are a proven tool for intra-operative hearing preservation, but have their limitations, suggesting the application of supplementary methods. This paper describes new developments of MCN and cochlear nerve monitoring in skull base surgery. Up to 2 x 8 EMG channels were recorded after bipolar stimulation of MCN using concentric coaxial probes. A special software enabled event-dependent registrations of all signals exceeding a definable threshold level. Selective recordings from masticatory muscles (N.V) were obtained using rectangular Teflon-insulated needle electrodes. For oculomotor (Nn.III/ VI) nerve recordings bipolar needle electrodes were precisely placed by orbital ultrasound guidance. Lower cranial nerves were monitored inserting needle electrodes into the soft palate (N.IX), tongue (N.XII) and vocal muscles (N.X) during laryngoscopy using a special applicator. For ABR recordings, click stimuli (95 dB HL) were applied monaurally through insert earphones. Electrocochleography was simultaneously recorded as a near-field potential without averaging after promontory (transtympanic) electrode placement using otomicroscopy. Regarding the ABR biosignal, a characteristic response pattern was detected following bipolar electrical stimulation of the auditory nerve possibly useful for its intra-operative identification.