Dexamethasone eluting electrodes for cochlear implantation: Effect on residual hearing

OBJECTIVE

The aim of this study was to compare a cochlear implant electrode array loaded with dexamethasone (DXM) with a conventional passive electrode array for the preservation of residual hearing in gerbils.

METHODS

Thirty Mongolian gerbils (Meriones unguiculatus) were implanted with an eluting electrode loaded with DXM (1 and 10%) on one side and a conventional passive electrode on the other side. Hearing thresholds were determined by tone bursts auditory brainstem responses at 4-6 weeks post-implantation and 1-year post-implantation for older gerbils.

RESULTS

After 4-6 weeks post-implantation, residual hearing was statistically more preserved with electrode arrays loaded with DXM, regardless of concentration, for the frequencies 16 000 Hz (P = 0.0008), 4000 Hz (P = 0.0038), 1000 Hz (P = 0.0349), and 500 Hz (P = 0.0030). After 1 year, the difference in favor of the DXM+ electrode array was found statistically significant only for the frequency 16 000 Hz (P = 0.0103) but against it for the frequencies 1000 Hz (P = 0.0368) and 500 Hz (P = 0.0010).

CONCLUSION

Electrode array with prolonged release of DXM improved short-term preservation of residual hearing after implantation for the frequencies 500, 1000, 4000, and 16 000 Hz in gerbils. The long-term results at 1 year confirmed these data for higher frequencies, but must be verified for the lower frequencies of 500 and 1000 Hz.

Characteristic differences in barrier and hygroscopic properties between normal and cosmetic dry skin. I. Enhanced barrier analysis with sequential tape-stripping

OBJECTIVE

Cosmetic dry skin often has a lower hydration level but a similar apparent barrier function, as measured by transepidermal water loss (TEWL), than that of the normal skin. To investigate the intrinsic difference in barrier property and moisture-holding ability between the cosmetic dry and normal skin, we developed a new clinical and data analysis procedure based on sequential tape-stripping with TEWL measurement, coupled with chemical analysis for protein and natural moisturizing factors (NMF) in the stratum corneum.

METHODS

A clinical study consisting of 64 healthy Caucasian female subjects with normal and cosmetic dry skin was conducted according to our clinical and data collection protocols. After the baseline visual dryness assessment, 20 tape-strips were placed and removed on each test site using D-Squame tapes. TEWL was measured at baseline and after the 5th, 10th, 15th and 20th tape-strips. All tapes were analysed for protein mass via chemical extraction and the Pierce BCA protein assay, as well as using an infrared densitometry device SquameScan 850A. The stratum corneum thickness and barrier quality (water transport resistance per thickness of the stratum corneum) were decoupled from the apparent barrier function using the TEWL and protein data.

RESULTS

A linear relationship between 1/TEWL and cumulative protein removal was observed for both normal and cosmetic dry skin. However, the slope of the linear relation was significantly steeper for normal skin, and significantly more protein was removed from cosmetic dry skin. The results showed that on average, the barrier quality of the stratum corneum of the normal skin is about 40% higher than that of the dry skin, whereas the stratum corneum of the dry skin is about 30% thicker than that of the normal skin. In addition, the amount of SC removal in sequential tape-stripping is generally non-uniform.

CONCLUSION

Our results demonstrated that there are characteristic differences in the barrier property between normal and cosmetic dry skin. In comparison to the normal skin, the stratum corneum of the cosmetic dry skin is considerably thicker, however, with a lower barrier quality. The results also showed that the amount of the SC removal in sequential tape-stripping is generally non-uniform. Therefore, the number of tape strips is not a good indicator for the tape-stripping depth.

Surgical complications and their implications for surgeons' well-being

BACKGROUND

Healthcare professionals can be seriously affected when they are involved in major clinical incidents. The impact of such incidents on staff is of particular relevance to surgery, as the operating room is one of the highest-risk areas for serious complications. This qualitative study aimed to assess the personal and professional impact of surgical complications on surgeons.

METHODS

This single time point study involved semistructured, individual interviews with general and vascular surgeons, consultants and senior registrars from two National Health Service organizations in London, UK.

RESULTS

Twenty-seven surgeons participated. Many were seriously affected by major surgical complications. Surgeons' practice was also often affected, not always in the best interest of their patients. The surgeons' reactions depended on the preventability of the complications, their personality and experience, patient outcomes and patients' reactions, as well as colleagues' reactions and the culture of the institution. Discussing complications, deconstructing the incidents and rationalizing were the most commonly quoted coping mechanisms. Institutional support was generally described as inadequate, and the participants often reported the existence of strong institutional blame cultures. Suggestions for supporting surgeons in managing the personal impact of complications included better mentoring, teamwork approaches, blame-free opportunities for the discussion of complications, and structures aimed at the human aspects of complications.

CONCLUSION

Those involved in the management of surgical services need to consider how to improve support for surgeons in the aftermath of major surgical incidents.

Intracranial meningiomas and neurofibromatosis type 2

PURPOSE

In spite of the few clinical studies regarding the occurrence of intracranial meningiomas, their prognosis in neurofibromatosis type 2 (NF2) has not been accurately assessed and their management remains controversial. This study aims to compare NF2 patients with intracranial meningiomas to those without, and consequently to identify prognostic factors in attempt to improve the management of these tumors.

METHODS

This retrospective study includes a total of 80 NF2 patients followed at Lille Hospital Center between 1987 and 2011. The diagnosis of NF2 was confirmed either because the patient met the Manchester criteria or by the presence of genetic mutation. Clinical, radiological and genetic data were retrospectively recorded and analyzed. Patients underwent annual cranial and spinal MRI. Both location and size of each tumor were reported.

RESULTS

The mean follow-up period was 8.8 years (range 1-24 years; SD: ±0.8) and the mean age at diagnosis was 27.2 years (range 6-73 years; SD: ±1.7). Among all patients, 34 harbored intracranial meningiomas. Patients with intracranial meningiomas had a higher number of intracranial schwannomas, spinal tumors and cutaneous tumors (p < 0.05). They underwent more surgical procedures (p < 0.012). Twenty five intracranial meningiomas were surgically removed in 17 patients. The decision to perform surgery was taken in 10 cases for symptomatic tumors and in 15 cases for growing asymptomatic tumors determined by radiology. The histological analysis found a high rate of fibroblastic, transitional or grade 2 meningiomas preferentially located at the cerebri falx.

CONCLUSION

Intracranial meningiomas are common in NF2. They are associated with poor prognosis factors. Clinical and radiological monitoring could lead to early treatment of these tumors both when clinical symptoms are present and in case of proven radiological evolution, and thus trying to maintain a favorable functional prognosis for as long as possible.

Percutaneous fixation of thoracolumbar fractures: current concepts

Numerous improvements in minimally invasive spine surgery (MISS) have been made during the last decade. MISS in thoracolumbar spine trauma management must achieve the same results as conventional treatment but with less morbidity. The increased use of MISS technologies in spine trauma has been correlated to the availability of more versatile instrumentation, which makes the fixation of all thoracic and lumbar levels possible. Balloon-assisted techniques have been used to support the anterior column in a stand-alone manner or in combination with open or percutaneous pedicle screw fixation. Fluoroscopy-assisted pedicle screw insertion is associated with less pedicle wall violation when compared to open surgery, but with increased radiation exposure for the surgeon and patient. Surgeons must be aware of this issue and new technologies are available to decrease irradiation. The advantages of percutaneous pedicle screw fixation relative to open surgery are discussed: preservation of posterior musculature, less blood loss, shorter operative time, lower infection risk, less postoperative pain, shorter rehabilitation time as well as shorter hospital stay. Limitations of percutaneous fixation include the inability to achieve direct spinal canal decompression and not having the option to perform a fusion. Nevertheless, these limitations can be addressed by combining MISS with open techniques. Indications for percutaneous spine fixation alone or in combination with MISS or open techniques are discussed based on the AO classification. The benefits of percutaneous spinal fixation for unstable spine fractures in polytrauma patients are also discussed. Posterior instrumentation can be easily removed after bone union to allow young patients to regain their mobility. Large well-controlled prospective studies are needed to draw up guidelines for less invasive procedures in spine trauma. In the future, development of new technologies can expand the scope of indications and treatment possibilities using MISS techniques in spine trauma.

Pre-, per- and postoperative factors affecting performance of postlinguistically deaf adults using cochlear implants: a new conceptual model over time

OBJECTIVE

To test the influence of multiple factors on cochlear implant (CI) speech performance in quiet and in noise for postlinguistically deaf adults, and to design a model of predicted auditory performance with a CI as a function of the significant factors.

STUDY DESIGN

Retrospective multi-centre study.

METHODS

Data from 2251 patients implanted since 2003 in 15 international centres were collected. Speech scores in quiet and in noise were converted into percentile ranks to remove differences between centres. The influence of 15 pre-, per- and postoperative factors, such as the duration of moderate hearing loss (mHL), the surgical approach (cochleostomy or round window approach), the angle of insertion, the percentage of active electrodes, and the brand of device were tested. The usual factors, duration of profound HL (pHL), age, etiology, duration of CI experience, that are already known to have an influence, were included in the statistical analyses.

RESULTS

The significant factors were: the pure tone average threshold of the better ear, the brand of device, the percentage of active electrodes, the use of hearing aids (HAs) during the period of pHL, and the duration of mHL.

CONCLUSIONS

A new model was designed showing a decrease of performance that started during the period of mHL, and became faster during the period of pHL. The use of bilateral HAs slowed down the related central reorganization that is the likely cause of the decreased performance.

Auditory brainstem implants: how do they work?

This review covers the design, structure, and function of auditory brainstem implants. Auditory brainstem implants (ABIs) are auditory prostheses initially designed to treat deafness in patients with neurofibromatosis type 2 (NF2). NF2 typically results in deafness due to disruption of the cochlear nerves. When the tumors are removed the auditory nerve is usually cut or nonfunctional anymore. In these cases, patients cannot benefit from peripheral devices such as cochlear implants (CI). Another cause of VIII nerve loss is bilateral temporal bone fracture. Worldwide, more than 500 persons have received an ABI after removal of the tumors that occur with NF2. More recently, some extensions of indications have been proposed to include subjects who would not benefit enough from a cochlear implant (i.e. cochlear ossification). The ABI is similar in design and function to a CI, except that the electrode is placed on the first auditory relay station in the brainstem, the cochlear nucleus (CN). The ABI electrode array is a small paddle that contains plate electrode contacts. The CN has not a single linear tonotopic organization from base to apex like the cochlea but different tonotopic subunits. The CN comprises multiple neuron types that are characterized by specific properties (morphology, regional distribution and cell-membrane characteristics), synaptic input and responses to acoustic stimuli. As the ABI electrode array is placed along the surface of the CN, each electrode likely activates a variety of neuron types, possibly with different characteristic frequencies. Patients undergoing ABI have variable benefit with regard to sound and speech comprehension. For the majority of patients, this improvement is essentially obtained by an augmentation of lip reading performances. Speech comprehension without lip-reading is not as good as with cochlear implants.

Role of riverine colloids in macronutrient and metal partitioning and transport, along an upland-lowland land-use continuum, under low-flow conditions

An assessment is made of the role of riverine colloids in macronutrient (nitrogen, phosphorus and carbon), metal and trace element partitioning and transport, for five rivers in the Ribble and Wyre catchments in north-western England, under baseflow/near-baseflow conditions. Cross-flow ultrafiltration was used to separate colloidal (<0.45 µm >1 kDa) and truly dissolved (<1 kDa) fractions from river water. Clear patterns were observed, along the upland-lowland land use continuum, in the partitioning and transport of macronutrients and metals between the colloidal, truly dissolved and acid-available particulate (>0.45 μm, suspended) fractions. Of these operationally-defined fractions measured, colloids were generally more important for both macronutrient and metal transport in the upland than in the lowland rivers. The results suggest that organic moieties in truly dissolved form from sewage effluent may have a greater capacity to chelate metals. Organic-rich colloids in the upland moorlands and metal oxide colloidal precipitates in the industrial rivers had a higher capacity for binding metals than the colloidal fractions in the urban and agricultural lowland rivers. Aggregation of these colloids may provide an important mechanism for formation of larger suspended particulates, accounting for a higher degree of metal enrichment in the acid-available particulate fractions of the upland moorland and lowland industrial rivers, than in the lowland agricultural and urban rivers. This mechanism of transfer of contaminants to larger aggregates via colloidal intermediates, known as 'colloidal pumping' may also provide a mechanism for particulate P formation and the high proportion of P being transported in the particulate fraction in the uplands. The cross-flow ultrafiltration data also allowed refinement of partition coefficients, by accounting for colloids within the solids phase and replacing the filtered (<0.45 μm) fraction with the truly dissolved (<1 kDa) concentrations. These provided a clearer description of the controls on metal and P partitioning along the upland-lowland continuum.

Communication strategies in acute health care: evaluation within the context of infection prevention and control

BACKGROUND

Communication in healthcare settings has recently received significant attention in the literature. However, there continues to be a large gap in current understanding of the effectiveness of different communication channels used in acute healthcare settings, particularly in the context of infection prevention and control (IPC).

AIM

To explore and evaluate the main communication channels used within hospitals to communicate with healthcare workers (HCWs) and to propose practical recommendations.

METHODS

Critical review of the main communication channels used within acute health care to communicate information to HCWs, and analysis of their impact on practice.

FINDINGS

The analysis covers verbal communications, standardization via guidelines, education and training, electronic communications and marketing strategies. Traditional communication channels have not been successful in changing and sustaining best practice in IPC, but newer approaches (electronic messages and marketing) also have pitfalls.

CONCLUSION

A few simple recommendations are made in relation to the development, implementation and evaluation of communications to HCWs; top-down vs bottom-up communications; and the involvement of HCWs, particularly ward personnel.

Bilateral cochlear implantation in children: localization and hearing in noise benefits

OBJECTIVE

The aim of this study was to report speech performance in quiet and in noise, sound localization with cochlear implanted children bilaterally. Their performances were compared also in unilateral conditions. In addition, speech and language evaluation was analyzed.

METHODS

Twenty-three children implanted with Neurelec Digisonic SP devices in 3 tertiary centres were tested on a battery of speech perception tests in quiet and in noise. Localization was assessed by lateralization tasks (90° and 30°). Progress in speech and language development and subjective assessment of benefit were assessed using several rating scales and questionnaires (categories of auditory perception, speech intelligibility rating, family participating rating scale).

RESULTS

Children scored better when tested in bilateral conditions rather than in unilateral conditions. In quiet, the mean scores for the poorer and better side were 52% and 73%, respectively. In the bilateral condition, the mean score increased to 83%. In noise, the mean scores were 39% and 57% respectively, which increased to a mean of 70% in the bilateral condition. Nine children (<9 years) completed the ±90° lateralization task. For both unilateral conditions performance was not significantly different from chance level. In the bilateral condition, the mean score was 86%. The ±30° lateralization score was completed by eight of the older children (>9 years). The scores in the unilateral conditions were closed to chance level, but significantly better in the bilateral condition (mean of 86%).

CONCLUSIONS

Performances in bilateral conditions were significantly better than in unilateral conditions on speech perception in quiet and in noise. Localization was significantly better when tested in the bilateral condition for ±90° lateralization task for the younger children and the ±30° task for the older children. All these results supported the hypothesis than bilateral cochlear implantation is more beneficial than unilateral implantation in children.

[Post-trauma mandibular osteoma]

INTRODUCTION

Osteomas are benign bone tumors with a slow progressive growth. These lesions are predominantly located in craniofacial sinuses, but other locations including mandible have been described. Their etiopathogenesis remains controversial. We report a case of post-trauma mandibular osteoma. Gardner syndrome was ruled out.

OBSERVATION

A 31-year-old female patient consulted for a peri-mandibular swelling present for the previous two years. On radiological examination, a bone sclerotic lesion was observed, located on the right lower mandibular edge. Patient history documented an initial trauma at the lesion site. Surgery was performed and anatomopathological examination confirmed the diagnosis of compact osteoma. There was no recurrence one year after surgery.

DISCUSSION

The etiopathogenesis of osteomas is controversial and several hypotheses are suggested. It is regarded as a true benign tumoral process, or abnormality of development, or as a reaction to trauma or infection. The development of osteoma after trauma has been described in several cases, notably in mandibular locations exposed to shocks (angle and lower edge). Multiple osteomas must mandatorily lead to screening for a Gardner's syndrome, because of the associated risk of colon cancer.

Multidisciplinary team working across different tumour types: analysis of a national survey

BACKGROUND

Using data from a national survey, this study aimed to address whether the current model for multidisciplinary team (MDT) working is appropriate for all tumour types.

PATIENTS AND METHODS

Responses to the 2009 National Cancer Action Team national survey were analysed by tumour type. Differences indicate lack of consensus between MDT members in different tumour types.

RESULTS

One thousand one hundred and forty-one respondents from breast, gynaecological, colorectal, upper gastrointestinal, urological, head and neck, haematological and lung MDTs were included. One hundred and sixteen of 136 statements demonstrated consensus between respondents in different tumour types. There were no differences regarding the infrastructure for meetings and team governance. Significant consensus was seen for team characteristics, and respondents disagreed regarding certain aspects of meeting organisations and logistics, and patient-centred decision making. Haematology MDT members were outliers in relation to the clinical decision-making process, and lung MDT members disagreed with other tumour types regarding treating patients with advanced disease.

CONCLUSIONS

This analysis reveals strong consensus between MDT members from different tumour types, while also identifying areas that require a more tailored approach, such as the clinical decision-making process, and preparation for and the organisation of MDT meetings. Policymakers should remain sensitive to the needs of health care teams working in individual tumour types.