Occurrence of mucosa-affecting diseases of the upper airways in middle ear cholesteatoma patients: a nationwide case-control study.

PURPOSE: Exploring a possible link between upper airway inflammation and the development of cholesteatoma by studying the association between mucosa-affecting diseases of the upper airways and cholesteatoma surgery. METHODS: This is a nationwide case-control study of 10,618 patients who underwent surgery for cholesteatoma in Sweden between 1987 and 2018. The cases were identified in the National Patient Register and 21,235 controls matched by age, sex and place of residency were included from national population registers. Odds ratios (OR) and corresponding 95% confidence intervals were used to assess the association between six types of mucosa-affecting diseases of the upper airways and cholesteatoma surgery. RESULTS: Chronic rhinitis, chronic sinusitis and nasal polyposis were more common in cholesteatoma patients than in controls (OR 1.5 to 2.5) as were both adenoid and tonsil surgery (OR > 4) where the strongest association was seen for adenoid surgery. No association was seen between allergic rhinitis and cholesteatoma. CONCLUSION: This study supports an association between mucosa-affecting diseases of the upper airways and cholesteatoma. Future studies should aim to investigate the mechanisms connecting mucosa-affecting diseases of the upper airways and cholesteatoma formation regarding genetic, anatomical, inflammatory and mucosa properties.

Ultrasound-assisted resection of oral tongue cancer.

BACKGROUND: In surgical resection of squamous cell carcinoma of the oral tongue (SCCOT), achieving clear margins is important for prognosis. Insufficient histopathological margins are common, particularly deep margins. AIMS/OBJECTIVES: The aim of the present study was to determine whether ultrasound (US)-assisted resection could decrease the proportion of insufficient histopathological deep margins in SCCOT. MATERIAL AND METHODS: 34 patients with SCCOT undergoing US-assisted resection (study group) were compared to 76 whose resections were performed without US (conventional group). Outcome measures were insufficient deep histopathological resection margins and mean difference in deep margins. RESULTS: Insufficient deep resection margins (<5.0 mm) were seen in 8 of 34 (23.5%) in the study group, compared to 31 of 76 (40.8%) in the conventional group, unadjusted RR 0.58 [95% CI 0.30-1.12; p = .11], adjusted RR 0.82 [95% CI 0.35-1.92; p = .64]. Unadjusted mean difference was 1.4 mm (95% CI 0.1-2.7, p = .04), adjusted mean difference 1.1 mm (95% CI -2.7 to 0.5, p = .19). CONCLUSIONS: Intraoperative US can visualize the deep resection margins in T1/T2 SCCOT. US-assisted resection seems to decrease the number of insufficient histopathological deep margins, though the results are not statistically significant. Comparatively good results in the conventional group is one explanation for the lack of significance. CLINICALTRIALS.GOV ID: NCT04059861.

Ultrasound accurately assesses depth of invasion in T1-T2 oral tongue cancer.

Background: Depth of invasion (DOI) is important for the T-classification of squamous cell carcinoma of the oral tongue (SCCOT) and incorporated in the TNM 8 classification of oral cavity cancer. To determine DOI clinical palpation is performed, but the preferred radiological modality remains controversial. The aim of this study was to investigate the assessment of DOI using ultrasound (US-DOI). Methods: The DOI was assessed in 40 patients with T1-T3 SCCOT by ultrasound, palpation, computed tomography and magnetic resonance imaging (MRI). Histopathological DOI (H-DOI) was gold standard. Bland-Altman analysis was used to compare mean difference and 95% limits of agreement (LOA). Results: The mean difference of US-DOI was -0.5 mm (95% LOA -4.9-4.0) compared to H-DOI and the mean difference for MRI was 3.9 mm (95% LOA -2.3-10.2). In the subgroup analysis of cT1-T2 the US-DOI mean difference was 0.1 mm and the 95% LOA limits -2.5-2.7. Conclusions: Ultrasound seems to be the most accurate method to assess DOI in T1-T2 SCCOT. MRI overestimates DOI and cannot assess a substantial proportion of the tumors. Level of Evidence: 2c.

Self-selective formation of ordered 1D and 2D GaBi structures on wurtzite GaAs nanowire surfaces.

Scaling down material synthesis to crystalline structures only few atoms in size and precisely positioned in device configurations remains highly challenging, but is crucial for new applications e.g., in quantum computing. We propose to use the sidewall facets of larger III-V semiconductor nanowires (NWs), with controllable axial stacking of different crystal phases, as templates for site-selective growth of ordered few atoms 1D and 2D structures. We demonstrate this concept of self-selective growth by Bi deposition and incorporation into the surfaces of GaAs NWs to form GaBi structures. Using low temperature scanning tunneling microscopy (STM), we observe the crystal structure dependent self-selective growth process, where ordered 1D GaBi atomic chains and 2D islands are alloyed into surfaces of the wurtzite (Wz) [Formula: see text] crystal facets. The formation and lateral extension of these surface structures are controlled by the crystal structure and surface morphology uniquely found in NWs. This allows versatile high precision design of structures with predicted novel topological nature, by using the ability of NW heterostructure variations over orders of magnitude in dimensions with atomic-scale precision as well as controllably positioning in larger device structures.

Operando Surface Characterization of InP Nanowire p-n Junctions.

We present an in-depth analysis of the surface band alignment and local potential distribution of InP nanowires containing a p-n junction using scanning probe and photoelectron microscopy techniques. The depletion region is localized to a 15 nm thin surface region by scanning tunneling spectroscopy and an electronic shift of up to 0.5 eV between the n- and p-doped nanowire segments was observed and confirmed by Kelvin probe force microscopy. Scanning photoelectron microscopy then allowed us to measure the intrinsic chemical shift of the In 3d, In 4d, and P 2p core level spectra along the nanowire and the effect of operating the nanowire diode in forward and reverse bias on these shifts. Thanks to the high-resolution techniques utilized, we observe fluctuations in the potential and chemical energy of the surface along the nanowire in great detail, exposing the sensitive nature of nanodevices to small scale structural variations.

Surgery for Chronic Otitis Media Causes Greater Taste Disturbance Than Surgery for Otosclerosis.

OBJECTIVES: Patients with otosclerosis more often complain about postoperative taste disturbance than patients with chronic otitis media, which seems paradoxical. We aim to investigate if and potentially why this seems to be the case, since the chorda tympani nerve (CTN) is thought to be severely traumatized less frequently during surgery in the former than in the latter. STUDY DESIGN: Prospective cohort study. SETTING: Department of Otorhinolaryngology at Hospital of Vastmanland, Vasteras, Sweden. PATIENTS: Sixty-five adults undergoing primary middle ear surgery were included. Thirty-seven were operated on for chronic suppurative otitis media with or without cholesteatoma (CSOM) and 28 for otosclerosis. INTERVENTIONS: Middle ear surgery due to otosclerosis or CSOM. Subjective and objective taste measurements and quality of life (QoL) questionnaire. MAIN OUTCOME MEASURES: Taste was assessed using electrogustometry (EGM) and the filter paper disc (FPD) method before and up to 1 year after surgery. Questionnaires on taste disturbance, including a visual analogue scale (VAS), and QoL were completed before and up to 1 year after surgery. RESULTS: Subjective taste disturbance anytime during the 1-year follow-up were reported by 62 and 46%, respectively. The difference in EGM 1 week after surgery compared with preoperative EGM was significantly greater among CSOM patients than otosclerosis. One year postoperatively, the difference is non-significant. CONCLUSION: Surgery for CSOM causes greater initial and more long-lasting taste disturbances as compared with surgery for otosclerosis. One-year postoperative taste normalizes for both CSOM and otosclerosis patients according to VAS and EGM measurements. No real change in QoL was seen 1-year postoperatively. LEVEL OF EVIDENCE: Level 2 evidence is prospective observational research with an experimental design.

Self-cleaning and surface chemical reactions during hafnium dioxide atomic layer deposition on indium arsenide.

Atomic layer deposition (ALD) enables the ultrathin high-quality oxide layers that are central to all modern metal-oxide-semiconductor circuits. Crucial to achieving superior device performance are the chemical reactions during the first deposition cycle, which could ultimately result in atomic-scale perfection of the semiconductor-oxide interface. Here, we directly observe the chemical reactions at the surface during the first cycle of hafnium dioxide deposition on indium arsenide under realistic synthesis conditions using photoelectron spectroscopy. We find that the widely used ligand exchange model of the ALD process for the removal of native oxide on the semiconductor and the simultaneous formation of the first hafnium dioxide layer must be significantly revised. Our study provides substantial evidence that the efficiency of the self-cleaning process and the quality of the resulting semiconductor-oxide interface can be controlled by the molecular adsorption process of the ALD precursors, rather than the subsequent oxide formation.

A randomized study of four different types of tympanostomy ventilation tubes - Full-term follow-up.

OBJECTIVE: To evaluate the impact of tympanostomy ventilation tube material (silicone vs fluoroplastic) and shape (short vs long) regarding time to extrusion, occurrence of otorrhea, occlusion, tube removal and occurrence of persistent perforation. METHODS AND MATERIAL: Four different types of ventilation tubes were used; Long Armstrong tubes, Donaldson tubes, Shepard tubes and straight tubes, representing four specific combinations of VT material (silicone or fluoroplastic) and shape (short, double flanged or long, single flanged). Four hundred children scheduled for bilateral tube insertion were included in a randomized trial. The patients received one type of tube in the right ear and another type in the left ear. The incidence of tube extrusion and complications were monitored postoperatively every third month by an otolaryngologist. RESULTS: Twenty-two children were excluded during surgery. Out of the studied 378 children the mean age was 35.3 months. 63.8% were boys. Short tubes extruded earlier than long tubes; hazard ratio (HR) 4.84 (95% CI 3.50-6.69, p < 0.001). Long Armstrong tubes were least prone to extrude. Silicone tubes resulted in significantly longer time to first infection in a VT ear, HR 1.68 (95% CI 1.03-2.76, p = 0.039). Donaldson tubes rendered the longest mean time to first infection (p = 0.025). Infections did not affect tube extrusion rates significantly (p = 0.879). No significant differences were found regarding tube occlusion, tube extraction or persistent perforation. CONCLUSIONS: Long tubes are less prone to extrude early. Long Armstrong tubes have the least propensity to extrude early. Silicone tubes render significantly longer time to first infection. Donaldson tubes result in least infections. Infection does not affect extrusion rates significantly. LEVEL OF EVIDENCE: 1b.

Electronic Structure Changes Due to Crystal Phase Switching at the Atomic Scale Limit.

The perfect switching between crystal phases with different electronic structure in III-V nanowires allows for the design of superstructures with quantum wells only a single atomic layer wide. However, it has only been indirectly inferred how the electronic structure will vary down to the smallest possible crystal segments. We use low-temperature scanning tunneling microscopy and spectroscopy to directly probe the electronic structure of Zinc blende (Zb) segments in Wurtzite (Wz) InAs nanowires with atomic-scale precision. We find that the major features in the band structure change abruptly down to a single atomic layer level. Distinct Zb electronic structure signatures are observed on both the conduction and valence band sides for the smallest possible Zb segment: a single InAs bilayer. We find evidence of confined states in the region of both single and double bilayer Zb segments indicative of the formation of crystal segment quantum wells due to the smaller band gap of Zb as compared to Wz. In contrast to the internal electronic structure of the nanowire, surface states located in the band gap were found to be only weakly influenced by the presence of the smallest Zb segments. Our findings directly demonstrate the feasibility of crystal phase switching for the ultimate limit of atomistic band structure engineering of quantum confined structures. Further, it indicates that band gap values obtained for the bulk are reasonable to use even for the smallest crystal segments. However, we also find that the suppression of surface and interface states could be necessary in the use of this effect for engineering of future electronic devices.

Clinical and audiological short-term and long-term outcomes of fat graft myringoplasty.

INTRODUCTION: Results of fat graft myringoplasty are often reported with only short-term follow-up. Audiological results are less commonly reported, as well as long-term follow-up results. MATERIALS AND METHODS: One hundred consecutive patients scheduled for fat graft myringoplasty were included in a prospective cohort study. Clinical and audiological outcomes were assessed at six weeks and one year postoperatively. RESULTS: Perforation sizes ranged from 0.5 to 4 mm. The six-week follow-up showed a total perforation closure rate of 72.9% with a statistically significant (p = .03) higher rate for the pediatric age group (83.0%). 64.4% of all patients were healed at one-year follow-up. Statistical analyses for background factors did not reveal any significant difference in healing rates with regard to patient sex or location or cause of the perforation. The mean preoperative air-conduction (AC) threshold was 25 dB with an air-bone gap of 12 dB. At the one-year follow-up the mean air conduction threshold for healed ears was improved to 16.6 dB, still 54.2% of them had a type B tympanogram. CONCLUSIONS: Children had a higher perforation closure rate at six-week follow-up than adult patients. Recurrent tympanic membrane perforations were common after initially successful fat graft myringoplasties. Long-term hearing was improved after successful fat graft myringoplasty, resulting in a mean AC threshold of 16.6 dB.

Post-tonsillectomy pain after using bipolar diathermy scissors or the harmonic scalpel: a randomised blinded study.

OBJECTIVE: To compare the postoperative pain following bipolar diathermy scissors tonsillectomy (higher temperature dissection) with harmonic scalpel tonsillectomy (lower temperature dissection). METHODS: Sixty patients aged 7-40 years planned for tonsillectomy with no other concurrent surgery were randomised to either bipolar diathermy scissors or harmonic scalpel as surgical technique. Blinded to the surgical technique, the patients recorded their pain scores (VAS, 0-10) at awakening and the worst pain level of the day in the postoperative period. All intake of pain medication was also recorded. RESULTS: No statistically significant differences were found between the two groups regarding postoperative pain levels or consumption of pain medication. CONCLUSION: Usage of the harmonic scalpel does not render less postoperative pain following tonsillectomy when compared with usage of the bipolar diathermy scissors.

Taste disturbance after stapes surgery: an evaluation of frequency, severity, duration, and quality-of-life.

CONCLUSION: The incidence of taste disturbance after stapes surgery is high (61.9%), whereas the majority (94.8%) recovers within 1 year. More severe surgical nerve trauma caused more disturbance, implying that the nerve should be handled carefully during surgery. OBJECTIVES: Patients operated on for otosclerosis seem more often to complain about post-operative taste disturbance than those operated on for chronic otitis media, although the chorda tympani nerve more seldom becomes maltreated in stapedotomy. These observations seem paradoxical. It is unclear to what extent a post-operative taste disturbance affects the quality-of-life. This study aims to shed light on the occurrence of post-operative taste disturbances, on possible prognostic factors, and to what extent post-operative taste disturbance impairs the quality-of-life. METHODS: One hundred and thirty-four adults undergoing primary stapedotomy were included. Questionnaires on taste disturbance and quality-of-life (SF-36) were answered before and after surgery, until 1 year post-operatively. RESULTS: Eighty-three (61.9%) study persons reported post-operative taste disturbance. Seven (5.2%) reported persisting disturbance at 1 year. Surgically more traumatized chorda tympani nerves correlated with more severe taste disturbance post-operatively than less traumatized. Taste disturbance at 1 year post-operatively correlate with a decrease of the physical function domain in the SF-36.

A randomized study of four different types of tympanostomy ventilation tubes - One-year follow-up.

OBJECTIVE: To compare four different types of tympanostomy ventilation tubes (VT); long-shaft and short-shaft silicone tubes and long-shaft and short-shaft fluoroplastic tubes, regarding time to extrusion and events of otorrhea. METHODS: A prospective randomized controlled trial in children with bilateral recurrent acute otitis media or secretory otitis media; four hundred children were randomized to receive one type of VT in the right ear and another type in the left ear. Postoperatively the children were assessed every third month by an otolaryngologist to monitor the incidence of otorrhea and tube extrusion. RESULTS: Out of the 400 children, 22 were excluded during surgery. Mean age was 35.3 months. A majority (63.8%) were boys. Forty-eight children were lost to follow up during the first year. Significantly more short-shaft VTs were extruded after 12 months compared to long-shaft VTs, regardless of material. Significantly higher incidence of otorrhea was found in the fluoroplastic VT ears compared to the silicone ones, regardless of length of tube. CONCLUSION: Long-shaft VTs last longer in the eardrum during the first year of treatment. Silicone tubes render a reduced risk of otorrhea during the first year of treatment.

Treatment of idiopathic rhinitis with kinetic oscillations - a multi-centre randomized controlled study.

CONCLUSIONS: The potential effects of KOS are still uncertain regarding the most effective air pressure to be used as well as the physiological effects on the nasal mucosa. The results of the study do not support a convincing treatment effect by KOS on IR. OBJECTIVES: Idiopathic rhinitis (IR) is a common disorder, affecting ∼10-20% of the population. A new method for treating IR, Kinetic Oscillation Stimulation (KOS), has been reported to have beneficial effects on total vasomotor symptom scores (TVRSS). The primary objective with this study was to evaluate if a mean pressure of 65 mbar, pressure amplitude of 100 mbar, and 68 Hz treatment with KOS had a positive effect on total vasomotor symptom scores (TVRSS), as compared with a mean pressure of 65 mbar, pressure amplitude of 4 mbar, and 68 Hz treatment in patients with idiopathic rhinitis. METHODS: Two hundred and seven patients were randomized (Full Analysis Set, FAS) in the study, including five visits and lasting for ∼25 weeks. All patients had two treatment episodes, and all patients had at least one treatment, meant as active, with high amplitude pressure for 10 min in each nostril. Group 1 had two such treatments, and Group 2 had one treatment with low amplitude pressure, initially meant as placebo, on one occasion. Because of numerical improvements in these two groups, a new control group, Group 3, was introduced. They had one new control treatment where the balloon was inserted into the nose, without any air inflation and without oscillations. RESULTS: KOS treatment with high amplitude pressure did not have significant beneficial effects as compared to low amplitude pressure on TVRSS. Numerical improvements in TVRSS and SNOT 22 were found when comparing high and low amplitude pressure treatments with uninflated balloon treatment. However, this part of the study was initially single-blinded, and these results were secondary objectives.

Factors influencing morbidity after paediatric tonsillectomy: a study of 18,712 patients in the National Tonsil Surgery Register in Sweden.

The objective of this study was to examine factors affecting morbidity after tonsillectomy in children. Data from the National Tonsil Surgery Register in Sweden on 18,712 patients who underwent tonsillectomy with or without simultaneous adenoidectomy between 1 and 18 years of age were analysed. This register includes data on sex, gender, surgical indication, and the surgical and haemostasis techniques used for each patient, as well as patient-reported outcomes for haemorrhage, analgesic use and antibiotic use. Comparison of patients who underwent surgery for infection versus upper airway obstruction revealed a significant increase in haemorrhage complications in the infection group. However, no significant difference remained after the adjustments for confounders in multivariable regression analysis. Instead, the increased risk among patients who underwent surgery for infection was mainly attributable to the use of bipolar diathermy and increased patient age. Patients who received surgery for infection reported more days of analgesic use, as well as more unplanned contacts with a health care service provider due to pain, compared with those who underwent surgery for upper airway obstruction. These results remained significant in multivariate analysis. The use of bipolar diathermy for haemostasis resulted in an increased risk, while the use of cold steel surgical instruments, a younger patient age and female sex led to a decreased risk. The surgical and haemostasis techniques used are the most important factors that affect morbidity after tonsillectomy in the paediatric age group. The choice of surgical techniques is of utmost importance for decreasing morbidity in these patients.

Electrical and Surface Properties of InAs/InSb Nanowires Cleaned by Atomic Hydrogen.

We present a study of InAs/InSb heterostructured nanowires by X-ray photoemission spectroscopy (XPS), scanning tunneling microscopy (STM), and in-vacuum electrical measurements. Starting with pristine nanowires covered only by the native oxide formed through exposure to ambient air, we investigate the effect of atomic hydrogen cleaning on the surface chemistry and electrical performance. We find that clean and unreconstructed nanowire surfaces can be obtained simultaneously for both InSb and InAs by heating to 380 ± 20 °C under an H2 pressure 2 × 10(-6) mbar. Through electrical measurement of individual nanowires, we observe an increase in conductivity of 2 orders of magnitude by atomic hydrogen cleaning, which we relate through theoretical simulation to the contact-nanowire junction and nanowire surface Fermi level pinning. Our study demonstrates the significant potential of atomic hydrogen cleaning regarding device fabrication when high quality contacts or complete control of the surface structure is required. As hydrogen cleaning has recently been shown to work for many different types of III-V nanowires, our findings should be applicable far beyond the present materials system.

Surface morphology of Au-free grown nanowires after native oxide removal.

Using scanning tunneling microscopy, we evaluate the surface structure and morphology down to the atomic scale for micrometers along Au-free grown InAs nanowires (NWs) free from native oxide. We find that removal of the native oxide (which covers the NWs upon exposure to the ambient air) using atomic hydrogen does not alter the underlying step structure. Imaging with sub-nanometer resolution along the NWs, we find an extremely low tapering (diameter change along the NW) of 1.7 ± 0.5 ŵm(-1). A surface morphology with monolayer high islands, whose shape was influenced by stacking faults, was found to cover the NWs and was attributed to the decomposed native oxide. The appearance of point defects in the form of As-vacancies at the surface is analyzed and we set limits to the amount of carbon impurities in the NWs.

Electronic and structural differences between wurtzite and zinc blende InAs nanowire surfaces: experiment and theory.

We determine the detailed differences in geometry and band structure between wurtzite (Wz) and zinc blende (Zb) InAs nanowire (NW) surfaces using scanning tunneling microscopy/spectroscopy and photoemission electron microscopy. By establishing unreconstructed and defect-free surface facets for both Wz and Zb, we can reliably measure differences between valence and conduction band edges, the local vacuum levels, and geometric relaxations to the few-millielectronvolt and few-picometer levels, respectively. Surface and bulk density functional theory calculations agree well with the experimental findings and are used to interpret the results, allowing us to obtain information on both surface and bulk electronic structure. We can thus exclude several previously proposed explanations for the observed differences in conductivity of Wz-Zb NW devices. Instead, fundamental structural differences at the atomic scale and nanoscale that we observed between NW surface facets can explain the device behavior.

Structural tympanic membrane changes in secretory otitis media and cholesteatoma.

BACKGROUND: Otitis media may predispose for retraction pathologic abnormality later in life. A weakening of the collagen fiber bundles in the lamina propria of the tympanic membrane (TM) is a prerequisite for the formation of a retraction pocket. Various collagen types have different tensile strength. The collagen-type distribution in the TM during otitis media and cholesteatoma has not been reported before. MATERIALS AND METHODS: The collagen contents of TM biopsies from child patients with longstanding secretory otitis media without retraction pockets were compared with pars tensa cholesteatomas using immunohistochemical staining for collagen Types I to IV. The histology was also investigated using transmission electron microscopy. RESULTS: The outer epithelium was in some biopsies thickened with evidence of edema. The biopsies showed an intact lamina propria with positive immunohistochemical staining for collagen Types I to III and showed normal collagen fiber bundles on electron microscopy. The outer epithelium of the cholesteatomas showed marked thickness variations and signs of edema. There was a presence of normal collagen fiber bundles in smaller parts of all cholesteatomas, positive for collagen Types I to II. In other parts, only scattered collagen fibers were found. CONCLUSION: Tympanic membrane biopsies from patients with longstanding secretory otitis media may show a thickening of the outer epithelium. Collagen Types I to III are present in the lamina propria, and no ultrastructural changes of the collagen fiber bundles are observed. Collagen is found in cholesteatomas in the remnants of the lamina propria, with positive staining for collagen Types I and II, whereas Type III seems to be lacking.

Evaluation of electrogustometry and the filter paper disc method for taste assessment.

CONCLUSION: The results indicate that electrogustometry and the filter paper disc method are reliable methods to measure taste with a high degree of reproducibility. OBJECTIVES: To thoroughly evaluate the reliability of electrogustometry and the filter paper disc method for taste assessments. METHODS: Thirty-nine healthy test persons without any history of chronic middle ear disease, aged between 27 and 62 years, were recruited. In all, 772 electrogustometry and 30 filter paper disc assessments were made. A nerve decay test was performed, with measures taken before and after eating sweet, sour, bitter, salt, a mild or spicy meal, after smoking, and after taking Swedish tobacco snuff ('snus'), as well as before and after local anesthesia of the tongue. Measurements were performed on 5 consecutive days and repeatedly during 1 day. The correlation between electrogustometry and the filter paper disc method was also studied. RESULTS: The results indicate that electrogustometry and the filter paper disc method are reliable methods to measure taste with a high degree of reproducibility. The only actions causing significant changes in the electrogustometry readings were eating a bitter substance and having local anesthesia of the tongue. The correlation between the methods was statistically significant except for the bitter flavor, where the correlation was just below the level of significance.