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Purpose: The increasing number of flexible ureteroscopy procedures, the fragility of devices and their repair costs are a burden for urological departments worldwide. The objective was to investigate the impact of 26 pre- and intraoperative factors on reusable flexible ureteroscope (fURS) damage., Methods: All procedures were conducted with reusable fURS: Karl Storz Flex-X2 or Olympus URF-V. Statistical analysis was performed in RStudio (1.0.136) with Chi-square test and Mann-Whitney U tests (MWU)., Results: In total, 416 flexible ureteroscopies, performed between September 2013 and June 2017, were analysed. 283 (68.03%) of these were for kidney stone surgery, and 133 (31.97%) for diagnostic purposes. In total, 39 (9.38%) devices were postoperatively deemed defective. The application of reusable laser fibre through fURS was more common in cases with documented defects [17/39 (43.59%) vs. 102/377 (27.06%), p = 0.047]. Other factors such as application of nitinol basket, biopsy via fURS, insertion of access sheath (UAS), as well as stone burden [median kidney stone maximal diameter: 6 mm (min 2.0; max 30.0) vs. 6 mm (min 1.0 vs. max 30.0)] showed no influence on fURS damage rate (p > 0.05). The infundibulopelvic angle (IPA) was steeper in cases with fURS damage as compared to cases without damage [median 44.0° (min 20.0; max 81.0) vs. 55.0 (min 7.0; max 122.0), p < 0.001]., Conclusions: Application of laser fibre via fURS can be considered as a risk factor of fURS damage. Stone burden, as well as the usage of not-sharp ended devices as nitinol baskets or forceps, is primarily not responsible for fURS damage.

Congenital cutaneous pyogenic granuloma is a rare benign vascular tumor with clinical and histopathological features similar to infantile hemangioma. It usually presents as a red, pedunculated and highly friable papule. On histopathological analysis, one can see a capillary vessel proliferation with lobular pattern and endothelial proliferation. The differential diagnosis is based on negativity of glucose transporter 1 (GLUT1) immunochemistry studies. We report two infants with congenital pyogenic granuloma, one with a unique cutaneous lesion and the other with multiple lesions affecting both skin and mucosal surfaces. These two cases highlight the importance of the differential diagnosis based on the GLUT1 immunochemistry analysis considering the distinct treatments required to these infant vascular tumors., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: Arterioureteral fistulas are rare, life-threatening, and difficult to diagnose. Risk factors are medical interventions in the lesser pelvis (general, urological, gynecological, and vascular surgery), radiation therapy of the lesser pelvis, permanent double J catheters, and previous vessel malformations., Materials and Methods: We retrospectively evaluated all cases of arterioureteral fistulas registered over the last 10 years in the clinic's documentation system. For all cases, clinical symptoms, diagnostics, therapies as well as clinical outcome were evaluated., Results: Four of the 5 patients were women. The most common initial symptom was a gross hematuria (4/5). All patients had a permanent double J catheter after extensive surgery of the lesser pelvis. In one case the initial diagnosis was done by retrograde ureterography, in 2 patients by provocative angiography and in the other 2 cases with a laparotomy due to cardiovascular problems. Three patients were treated by open surgery and 2 patients were treated by stenting of the iliac artery. One patient died, 2 patients had a permanent kidney fistula, and 2 patients continued treatment with a permanent double J catheter., Conclusion: Based on the more aggressive therapy regimens, we expect that the number of patients presenting with arterioureteral fistulas will continue to rise. The identification of these patients based on their risk profile is essential.

Objective: The increasing number of flexible ureterorenoscopy (fURS) procedures, the fragility of devices, and their growing repair costs represent a substantial burden for urological departments worldwide. No risk factors of flexible ureteroscope damage have been identified so far. The objective of this study was to investigate the impact of infundibulopelvic angle (IPA) on device damage and on other intraoperative and postoperative factors such as length of hospital stay, surgical complications, stone-free rate (SFR), operation, and fluoroscopy time., Materials and Methods: In a retrospective monocentric study, IPA was measured based on intraoperative retrograde pyelography images taken during fURS. All procedures were conducted with modern reusable flexible ureteroscopes: Karl Storz Flex-X2 or Olympus URF-V. Statistical analysis was performed in RStudio (version 1.0.136) with the unpaired t-test and Mann-Whitney U test. Pearson correlation coefficient (Pearson's r) was measured whenever applicable., Results: In total, 381 fURS performed between September 2013 and March 2017 were analyzed: 260 (68.24%) for kidney stone operation and 121 (31.76%) for diagnostic purposes; of these, 38 (9.97%) devices were postoperatively deemed defective. IPA values were significantly steeper in cases with flexible ureteroscope damage compared to cases without damage (median 42.5 degrees vs 56.0, p < 0.001). Steeper IPA was significantly associated with the occurrence of Clavien-Dindo ≥2 complications (median 51.0 degrees vs 55.0, p = 0.005) as well as prolonged hospital stay (median 51.0 degrees vs 55.0, p = 0.014). No influence on SFR was observed (p > 0.05). IPA did not correlate with operation or fluoroscopy time., Conclusions: Steep IPA can be considered the first risk factor predicting both flexible ureteroscope damage and an unfavorable postoperative course. A better understanding of damage mechanisms is the key for the proper indications to use costly single-use devices.

Objective: The increasing number of flexible ureterorenoscopy (fURS) procedures, the fragility of devices, and their growing maintenance and repair costs represent a substantial burden for urologic departments. Disposable single-use fURS devices offer many advantages over reusable fURS. Among them, the LithoVue™ model shows the best clinical utility. In our study, we assessed the economic aspects of reusable fURS application compared with the potential costs and benefits of single-use fURS (LithoVue™). Indications for single-use fURS were proposed based on potential risk factors of reusable fURS damage., Materials and Methods: This single-center retrospective analysis compared the actual cost of reusable fURS procedures with the potential costs of LithoVue™ based on the price offered by the manufacturer. Consecutive case analysis of damaged fURS was performed to determine potential risk factors associated with fURS damage., Results: The study group consisted of 423 reusable fURS procedures conducted between January 2013 and December 2016. During this period, 102 (24.11%) diagnostic fURS and 321 (75.89%) fURS for kidney stone therapy were performed. In 32 of 423 (7.57%) fURS cases, devices were postoperatively deemed defective, 9 of which were used for diagnostic procedures (9/102; 8.82%), 7 for stone removal (7/148; 4.73%), and 16 for stone removal and laser (Ho:YAG) application (16/173; 9.25%). The average cost per reusable fURS procedure was found to be €503.26., Conclusions: Disposable fURS is a more expensive option for high-volume centers. Based on our case analysis, laser disintegration treatment of multiple, large stones in the lower kidney pole of recurrent stone formers, as well as a steep infundibulopelvic angle (IPA ≤50°), seems to be the main risk factor for fURS damage. For these cases, disposable fURS may be a cost-effective alternative; however, a prospective comparison of economic outcomes between disposable and reusable fURS, together with confirmation of the proposed damage risk factors, is needed.

Background: Perforations of the nasal septum can be very disturbing for patients due to increased crust formation, nose bleeds, obstruction of nasal breathing and whistling sounds during nasal breathing. The aim of this study was to evaluate how the symptom burden can be alleviated by custom-made silicone buttons derived from an impression mold., Material and Methods: A retrospective study was carried out to evaluate 45 patients with symptomatic septal perforations, who have been treated over a period of 8 years. The magnitude and localization of the perforations were measured on the impression molds as well as in situ in 28 patients. The symptoms were rated on a visual analogue scale (VAS) before and after treatment (response 64%)., Results: No correlation was found between the size of the perforation and the distance from the nasal opening. Of the patients 31 (69%) still had the septal button in situ at the time of the last follow-up. The magnitude and localization of the perforation were not found to be predictors of treatment success. The following symptoms showed a highly significant improvement: crust formation (VAS median 75 vs. 31), nose bleeds (VAS median 50 vs. 0), obstruction of nasal breathing (VAS median 84 vs. 14) and whistling breathing sounds (VAS median 69 vs. 0). Unpleasant odor and symptoms of sinusitis did not show significant changes. The long-term septal button carriers rated the improvement with a median of 91% on the VAS., Conclusion: The success of prosthetic closing of septal perforations by a custom-made button still cannot be accurately predicted. The majority of patients were extraordinarily satisfied because the symptom burden could be significantly reduced.

Background: The utilization of craniofacial prosthesis has proven to be very successful for craniofacial defects. However, there is a lack of knowledge about the value of an epithesis for voice rehabilitation in patients with tracheostomy. The aim of this study was to describe application of the tracheostomy epithesis and to present a systematic analysis of the functional results of this prosthetic technique., Materials and Methods: This retrospective analysis included 48 patients on follow-up being treated in three different centers after laryngectomy and/or tracheostomy between 2008 and 2014. Subjects were given a questionnaire with items such as speech quality, quality of life, free hand speech ability, respiratory quality and sufficient tracheostomal sealing comparing values before and after application of an individually custom-made tracheostomy epithesis. Twenty-eight answered the questionnaire and could be reported., Results: Twenty-eight of 48 patients were consistently being included in follow-up. The statistical analysis revealed a significant improvement of tracheostoma occlusion (p < 0.05) and improvement in free hand speech ability (p < 0.05). A leakage of air during voice production could be prevented in 59.3% after application of an epithesis. Quality of life correlated directly with successful utilization of an epithesis., Conclusion: In the literature, different industrialized products are described to realize occlusion of the tracheostoma for sufficient speech production without using the hands. In numerous cases commercial solutions fail and the patients need individual modifications. Our study first describes the evaluation of custom-made tracheostomal epithesis. From our observed results we advocate the individual tracheostomal epithesis as a durable solution for voice rehabilitation.

The past century saw rapid development of craniofacial prostheses. Particularly the challenging issue of surgical fixation was the subject of intensive research and development. During the past three decades, the principle of osseointegration has proven to provide a reliable method for epithesis fixation. The continuous technical development of implant systems has led to almost minimally invasive surgical techniques, with ever increasing stability of the implants. Osseointegrated implants are a proven and durable solution in the rehabilitation of the patient with a defect in the craniofacial region. Overall complication rates are low. The design and mechanics of the implants, as well as the artificial body of the epithesis itself, are topics of current medical-technical research by anaplastologists and surgeons. Finally, functional prostheses, such as the tracheostomy epithesis, deserve particular attention.

The nociceptive flexion reflex (NFR) is a widely used tool to investigate spinal nociception for scientific and diagnostic purposes, but its clinical use is currently limited due to the painful measurement procedure, especially restricting its applicability for patients suffering from chronic pain disorders. Here we introduce a less painful algorithm to assess the NFR threshold. Application of this new algorithm leads to a reduction of subjective pain ratings by over 30% compared to the standard algorithm. We show that the reflex threshold estimates resulting from application of the new algorithm can be used interchangeably with those of the standard algorithm after adjusting for the constant difference between the algorithms. Furthermore, we show that the new algorithm can be applied at shorter interstimulus intervals than are commonly used with the standard algorithm, since reflex threshold values remain unchanged and no habituation effects occur when reducing the interstimulus interval for the new algorithm down to 3s. Finally we demonstrate the utility of the new algorithm to investigate the modulation of nociception through different states of attention. Taken together, the here presented new algorithm could increase the utility of the NFR for investigation of nociception in subjects who were previously not able to endure the measurement procedure, such as chronic pain patients., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Background: By virtue of direct bone conduction, percutaneous bone-anchored hearing implants offer a high level of wearing comfort, as well as audiologically superior signal transmission due to less dampening. Over the years, titanium implants have been optimized and the surgical technique developed into a minimally invasive intervention without soft tissue reduction. This study aims to investigate the success rates of the various percutaneous implant systems., Materials and Methods: This retrospective study includes 191 patients who received a total of 283 percutaneous titanium implants for bone conduction hearing systems during the period from 01.01.1989 until 31.12.2013. Patient age ranged from 2 to 81 years (mean 36 years). The mean follow-up duration was 5.2 years., Results: The overall osseointegration success rate was 92.6% and ranged from 90.5 to 100% for the various implant systems (p = 0.6). For children and adolescents, the success rate was 86.8%, compared to 95.2% in adults (p = 0.023). Classical soft tissue reduction was received by 185 patients, mainly via the dermatome technique. The linear incision technique was used in 3.8% of cases and the technique without soft tissue reduction in 3.7% of cases. Revision surgery for soft tissue problems was performed in 4.2% of cases., Conclusion: Success rates in adults were significantly higher than those in children and adolescents. Although success rates improved with the development of new systems, this did not reach statistical significance. Minimally invasive surgery without soft tissue reduction is considered state of the art.

We present a microfluidic apparatus and method for the measurement of asphaltene content in crude-oil samples. The measurement is based on an optical absorption technique, where it was established that asphaltene coloration correlated linearly with asphaltene weight content. The initial absorbance of the oil is measured, and asphaltenes are removed from the oil by the addition of n-alkane, leading to flocculation and subsequent filtration. The absorbance of the deasphalted oil (maltenes) is then measured, and the initial asphaltene content is revealed by the change in absorbance. The asphaltene optical densities correlated linearly with conventional weight measurement results (e.g., ASTM D6560) for 38 crude-oil samples from around the world. Sample measurement repeatability was shown to be within ±2% over several months. Other aspects influencing performance of the system were evaluated, including plug dispersion, flocculation kinetics, membrane degradation, and channel clogging. The microfluidic approach described here permits asphaltene content measurement in less than 30 min as opposed to days required with traditional gravimetric techniques. This many-fold reduction in measurement time will enable more frequent characterization of crude oil samples.

Movement and haemodynamic responses to noxious stimuli during general anaesthesia are regarded as signs of nociception. We compared the Nociceptive Flexion Reflex Threshold (NFRT), Bispectral Index (BIS), Composite Variability Index (CVI), Noxious Stimulation Response Index (NSRI) and the calculated propofol/remifentanil effect-compartment concentrations (Ce) as predictors for such responses in 50 female subjects at laryngeal mask airway insertion and skin incision. The following prediction probabilities (PK-values) were obtained at laryngeal mask airway insertion and skin incision, respectively. For movement responses: NFRT = 0.77 and 0.72; p = 0.0001 and 0.004, respectively; BIS = 0.41 and 0.56, p = 0.29 and 0.5, respectively; CVI = 0.48 and 0.57, p = 0.76 and 0.88, respectively; NSRI = 0.49 and 0.76, p = 0.92 and 0.0001, respectively; propofol-Ce = 0.35 and 0.66, p = 0.04 and 0.03, respectively; remifentanil-Ce = 0.68 and 0.72, p = 0.01 and 0.003, respectively. For heart rate responses: NFRT = 0.68 and 0.75, p = 0.04 and 0.01, respectively; BIS = 0.37 and 0.59, p = 0.15 and 0.41, respectively; CVI = 0.41 and 0.44, p = 0.39 and 0.37, respectively; NSRI = 0.48 and 0.53, p = 0.84 and 0.78, respectively; propofol-Ce = 0.42 and 0.56, p = 0.39 and 0.53, respectively; remifentanil-Ce = 0.58 and 0.54, p = 0.35 and 0.73, respectively. We conclude that the NFRT best predicts movement and heart rate responses to noxious stimuli. Effect-compartment concentrations and NSRI also predict movement (but not heart rate) responses satisfactorily., (Anaesthesia © 2012 The Association of Anaesthetists of Great Britain and Ireland.)

The Drosophila adult posterior midgut has been identified as a powerful system in which to study mechanisms that control intestinal maintenance, in normal conditions as well as during injury or infection. Early work on this system has established a model of tissue turnover based on the asymmetric division of intestinal stem cells. From the quantitative analysis of clonal fate data, we show that tissue turnover involves the neutral competition of symmetrically dividing stem cells. This competition leads to stem-cell loss and replacement, resulting in neutral drift dynamics of the clonal population. As well as providing new insight into the mechanisms regulating tissue self-renewal, these findings establish intriguing parallels with the mammalian system, and confirm Drosophila as a useful model for studying adult intestinal maintenance.

Following the great success of traditional microfluidic devices across many disciplines, a new class of microfluidic systems emerged in recent years, which features finely tuned, localized surface modifications within the microstructures in order to keep up with the demand for devices of ever increasing complexity (lab on chip, assay on chip, etc.). Graft photopolymerization has become a powerful tool for such localized surface modifications particularly in combination with poly(dimethylsiloxane) (PDMS) devices, as it is compatible with many functional monomers and allows for high spatial resolution. However, application within enclosed PDMS microstructures and in particular well-controlled surface-directed polymerization remains challenging. Detailed understanding of the interaction between photoinitiator, benzophenone (BP), and polymer matrix is needed. We have developed a visualization technique, which allows for observation of reacted BP in situ within the PDMS matrix. We present a detailed study on solvent-driven BP diffusion providing results essential to successful surface treatment. We also identified and investigated photoinitiator inhibition by oxygen and provide appropriate mitigation strategies.

Many microfluidic applications require modified surface wettability of the microchannels. Patterning of wettability within enclosed microfluidic structures at high spatial resolution has been challenging in the past. In this paper, we report an improved method for altering the surface wettability in poly(dimethylsiloxane) (PDMS) microchannels by UV-induced graft polymerization of poly(acrylic acid). Our method presents significant improvements in terms of wettability contrast and spatial resolution of the patterned structures as compared to recent literature and is in particular applicable to complex microfluidic structures with a broad range of channel sizes and aspect ratios. A key part of our work is the clear description of the surface treatment process with the identification of key parameters, some of which have been overlooked, neglected, or misinterpreted in previous works. We have studied these key parameters in detail and provide recommended values for each parameter supported by experimental results. This detailed understanding of the treatment process and the effects of the critical parameters on it allowed us to significantly improve quality and reliability of the treatment process.

Background: Beyond surgery, conventional radiation therapy, and chemotherapy brachytherapy may enrich treatment of primary, residual, or recurrent head and neck cancer. Nasopharyngeal cancer is a proper indication for intracavitary brachytherapy which can be performed using a commercial applicator system or an individual applicator., Methods and Patients: Technique for manufacturing an individual nasopharyngeal silicon applicator and its experiences in 3 patients (2 times brachytherapy in treatment regime of primary nasopharyngeal cancer, 1 time for nasopharyngeal lymphoma treatment) are presented., Results: Under general anaesthesia in all 3 patients nasopharyngeal imprinting after placement of two suction tubes was performed with shore 12 silicon and followed by manufacturing the individual silicon applicator with two included tubes after plaster cast of the imprinting form has been performed. This silicon applicator enabled safe endocavitary brachytherapy using the high-dose-rate-afterloading-method. Tumor control was achieved in all 3 patients., Conclusions: The presented individual silicon applicator is suited for intracavitary brachytherapy of the nasopharynx being an valuable contribution in the primary treatment regime of nasopharyngeal cancer.

Three-layer neural-network functions were developed to transform spectral representations of pinna-filtered stimuli at the input to a space-mapped representation of sound-source direction at the output. The inputs are modeled after transfer functions of the external ear of the cat; the output is modeled on the spatial sensitivity of superior colliculus neurons. Network solutions are obtained by backpropagation and by a method that enforces uniform task distribution in the hidden layer of the model. Solutions are characterized using bandlimited inputs to study the relative strength of potential sound localization cues in various frequency regions. This analysis suggests that the frequency region containing the first spectral notch (5-18 kHz) provides the best localization cues. Response properties of model neurons were studied using input patterns modeled after auditory nerve response profiles to pure tones at various frequencies and sound levels. The response properties of hidden layer model neurons resemble cochlear nucleus types III and IV and their composites. Neurons in both hidden and output layers show the properties of spectral notch detectors. Although neural networks have limitations as models of real neural systems, the results illustrate how they can provide insight into the computation of complex transformations in the nervous system.

An application of neural network modeling is described for generating hypotheses about the relationships between response properties of neurons and information processing in the auditory system. The goal is to study response properties that are useful for extracting sound localization information from directionally selective spectral filtering provided by the pinna. For studying sound localization based on spectral cues provided by the pinna, a feedforward neural network model with a guaranteed level of fault tolerance is introduced. Fault tolerance and uniform fault tolerance in a neural network are formally defined and a method is described to ensure that the estimated network exhibits fault tolerance. The problem of estimating weights for such a network is formulated as a large-scale nonlinear optimization problem. Numerical experiments indicate that solutions with uniform fault tolerance exist for the pattern recognition problem considered. Solutions derived by introducing fault tolerance constraints have better generalization properties than solutions obtained via unconstrained back-propagation.