The efficacy of bone-anchored hearing implant surgery in children: A systematic review.

OBJECTIVE: To evaluate the efficacy of Bone-Anchored Hearing implants (BAHIs) in children and to elucidate the usage and outcomes of new surgical techniques and implants in this specific population. DATA SOURCES: Embase and PubMed. STUDY SELECTION: We identified studies evaluating surgical outcomes of BAHIs in children. Retrieved articles were screened using predefined inclusion and exclusion criteria. Critical appraisal included directness of evidence and risk of bias. Studies that successfully passed critical appraisal were included. DATA EXTRACTION: Outcome measures included patient demographics, follow-up time, surgical technique (one-versus two-stage surgery), tissue handling technique (reduction versus preservation), type of implant used, and complications. DATA SYNTHESIS: We selected 20 articles published between 2000 and 2017 for data extraction, encompassing 952 implanted BAHIs. The overall mean age at implantation was 8.6 years (range, 2-21 years). Adverse soft-tissue reactions occurred in 251 of the 952 implants (26.4%; range 0%-89% across studies). Revision surgery was performed in 16.8% (142 of the 845) of the implants. The total rate of implant loss, i.e. caused by OIF (n = 61), trauma (n = 33), recurrent infection (n = 15), elective removal due to insufficient benefit (n = 1), cosmetic reasons (n = 1), or unknown reason (n = 16), was 13.3% of the implants (127 out of 952; range 0%-40% across studies). Differences are seen in the type of implants used; wide-diameter implants seem to be superior in terms of implant survival, and similar in terms of adverse skin reactions, while one-stage surgery and soft-tissue preservation do not seem to result in higher implant loss rates or increased adverse skin reactions based upon limited amounts of literature. CONCLUSION: In general, BAHIs are a safe method for hearing rehabilitation in children, although large differences between studies are observed. The outcomes of new surgical techniques and implant designs in the pediatric population seem promising, but more research is needed before definitive conclusions can be drawn.

Adjuvant radiotherapy in sinonasal mucosal melanoma: A retrospective analysis.

OBJECTIVES: Evaluation of outcome after curative treatment for sinonasal mucosal melanoma focused on the effect of adjuvant radiotherapy on recurrence and survival. DESIGN: Retrospective chart analysis. SETTING: Tertiary referral hospital. PARTICIPANTS: Fifty-one patients with primary sinonasal mucosal melanoma who underwent surgical resection with curative intention between 1980 and 2016 at Erasmus Medical Center, Rotterdam. MAIN OUTCOME MEASURES: Patients were categorised into 2 groups: surgery alone and surgery with adjuvant radiotherapy. Log-rank test was used to compare rates of recurrence and survival between treatment groups. Predictors for treatment modality, recurrence and survival were assessed with multivariate statistical analysis. RESULTS: Of all patients, 23.5% developed local recurrence and 47.1% developed distant metastasis. Estimated 5-year disease-free survival was 25.2%, and 5-year overall survival (OS) was 38.1%. Forty-three patients (84.3%) were treated with post-operative radiotherapy. Patients who underwent surgery with adjuvant radiotherapy presented more often with high tumour stage, tumour involving multiple sites and positive margins. Post-operative radiotherapy seemed to be associated with better local control (P = .549). No effect was found on occurrence of distant metastasis and OS. Positive margin status was an independent negative predictor for distant metastasis-free survival and overall survival. CONCLUSIONS: Our treatment outcomes are consistent with literature. Post-operative radiotherapy seems to be associated with improved local control despite advanced disease and positive margin status in this treatment group.

Interface Engineering to Create a Strong Spin Filter Contact to Silicon.

Integrating epitaxial and ferromagnetic Europium Oxide (EuO) directly on silicon is a perfect route to enrich silicon nanotechnology with spin filter functionality. To date, the inherent chemical reactivity between EuO and Si has prevented a heteroepitaxial integration without significant contaminations of the interface with Eu silicides and Si oxides. We present a solution to this long-standing problem by applying two complementary passivation techniques for the reactive EuO/Si interface: (i) an in situ hydrogen-Si (001) passivation and (ii) the application of oxygen-protective Eu monolayers-without using any additional buffer layers. By careful chemical depth profiling of the oxide-semiconductor interface via hard x-ray photoemission spectroscopy, we show how to systematically minimize both Eu silicide and Si oxide formation to the sub-monolayer regime-and how to ultimately interface-engineer chemically clean, heteroepitaxial and ferromagnetic EuO/Si (001) in order to create a strong spin filter contact to silicon.

Diving reflex: can the time course of heart rate reduction be quantified?

In this meta-analysis of diving bradycardia in humans, we sought to quantify any heart rate (HR) reduction using a relatively simple mathematical function. Using the terms "diving reflex,""diving bradycardia,""diving response,""diving plus heart rate," databases were searched. Data from the studies were fitted using HR=c+aexp(-(t-t(0))/τ), where c is the final HR, a is the HR decrease, τ is the time constant of HR decay, and t(0) is the time delay. Of 890 studies, 220 were given closer scrutiny. Only eight of these provided data obtained under comparable conditions. Apneic facial immersion decreased HR with τ=10.4 s and in air alone it was less pronounced and slower (τ=16.2 s). The exponential function fitted the time course of HR decrease closely (r(2)>0.93). The fit was less adequate for apneic-exercising volunteers. During apnea both with and without face immersion, HR decreases along a monoexponential function with a characteristic time constant. HR decrease during exercise with and without face immersion could not readily be described with a simple function: the parasympathetic reaction was partially offset by some sympathetic activity. Thus, we succeeded in quantifying the early time course of diving bradycardia. It is concluded that the diving reflex is useful to diagnose the integrity of efferent cardiovascular autonomic pathways.

[Tissue engineering of erectile nerves]. / Tissue Engineering erektiler Nerven.

Dissection of the cavernous nerves eliminates spontaneous erections and may lead to irreversible erectile dysfunction due to degeneration of cavernous tissue. Novel procedures to reconstruct penile innervation include cavernous nerve interposition grafting and neurotrophic treatments to revitalize penile neural input, evaluated thus far in various preclinical models of cavernous nerve injury. Schwann cells crucially contribute to successful axonal regeneration by mechanical and paracrine mechanisms in the injured nerve, and Schwann cells seeded into guidance channels have been successfully employed to support regeneration in animal models of cavernous nerve injury. Gene therapy, tissue engineering, and reconstructive techniques have been combined to deliver neurotrophic factors and recover erectile function.

Schwann cell seeded guidance tubes restore erectile function after ablation of cavernous nerves in rats.

PURPOSE: Dissection of the cavernous nerves eliminates spontaneous erections. We evaluated the ability of Schwann cell seeded nerve guidance tubes to restore erections after bilateral cavernous nerve resection in rats. MATERIALS AND METHODS: Sections (5 mm) of the cavernous nerve were excised bilaterally, followed by immediate bilateral microsurgical reconstruction. In 10 animals per group (20 study nerves) reconstruction was performed by genitofemoral nerve interposition, interposition of silicone tubes or interposition of silicone tubes seeded with homologous Schwann cells. As the control 10 animals (20 study nerves) underwent sham operation (positive control) and bilateral nerve ablation (without reconstruction) was performed in a further 10 (negative control). Erectile function was evaluated 3 months postoperatively by relaparotomy, electrical nerve stimulation and intracavernous pressure recording. RESULTS: After 3 months neurostimulation resulted in an intact erectile response in 90% (18 of 20) of Schwann cell grafts, while treatment with autologous nerves (30% or 6 of 20) or tubes only (50% or 10 of 20) was less successful (p <0.01). Whereas untreated ablated rats showed no inducible erections (0% or 0 of 20), all sham operated animals had an intact erectile response (100% or 20 of 20). Maximum intracavernous pressure upon electrostimulation was significantly elevated using Schwann cell grafts compared to results in the other treatment groups (p <0.001). Morphological evaluation revealed advanced regeneration within Schwann cell grafts. CONCLUSIONS: Schwann cell seeded guidance tubes restore erectile function after the ablation of cavernous nerves in rats and they are superior to autologous nerve grafts.

A comparison of trans-tibial amputee suction and vacuum socket conditions.

Daily volume loss of the stump leads to a poor fit of the prosthetic socket. A method of preventing this volume loss and maintaining a good fit was developed. A vacuum (-78 kPa) was drawn on the expulsion port of a total surface-bearing suction socket to hold the liner tightly against the socket. Stump volume of 10 trans-tibial amputees was measured prior to and immediately after a 30 minute walk with normal and vacuum socket conditions. Under the normal condition, the limb lost an average of 6.5% of its volume during the walk. In contrast, with the liner held tightly by vacuum, the limb gained an average of 3.7% in volume. It is believed that the difference observed between conditions resulted from a greater negative pressure developed during the swing phase of gait with the vacuum condition. X-rays revealed that the limb and tibia pistoned 4 mm and 7 mm less, respectively, under the vacuum condition. The combination of reduced pistoning and maintenance of volume is thought to account for the more symmetrical gait observed with the vacuum.