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The Future Circular Hadron Collider design studies proposed a novel dual chamber beam screen consisting of copper and stainless steel. However, one concern about the current design is the inherent resistive wall beam impedance of the beam screen, which may not be low enough to guarantee stable beam operation especially critical on the vertical plane. In order to reduce the resistive wall beam impedance as much as possible while keeping the dipole field quality within specifications, a hybrid beam screen consisting of REBCO-CC and Cu is proposed for the inner chamber of the beam screen. We performed a comprehensive position and REBCO-CC content study, leading to an optimum configuration for a REBCO-CC-Cu hybrid design. These studies utilized measured values of REBCO-CC surface impedance obtained under realistic FCC-hh conditions. The calculations were carried out by combining numerical simulations and beam coupling impedance theory for general beam pipe cross sections, where we found a substantial decrease in the vertical resistive wall beam impedance by about an order of magnitude compared to the nominal beam screen design made of copper. Limitations of the proposed design and possible mitigation actions are also discussed. [ABSTRACT FROM AUTHOR]

Purpose: Early facial nerve palsy (eFNP) is the most frequent complication of the parotidectomy. Intraoperative neuromonitoring (IONM) in parotid surgery, which aims at reducing eFNP, has not evolved any further than the mere differentiation between the nerve and the surrounding tissue. Continuous IONM (cIONM), used in thyroid and posterior fossa surgery, has developed over the past years and has proved beneficial in reducing the rate of paresis in cases where a pattern of impending nerve injury is identified. In this study, we aim to demonstrate the safety of using the stimulating electrode (Saxophone®) for cIONM in parotid surgery. Methods: From 2016 to 2018, 40 patients who were referred for primary parotidectomy under cIONM according to our study protocol (registered at the German Clinical Trials Register, DRKS-ID: DRKS00011051, http://www.drks.de; http://apps.who.int/trialsearch) were included in this study. All patients with a normal preoperative facial nerve function [House–Brackman (HB)-Index 1] underwent surgery using continuous facial nerve stimulation with the Saxophone® electrode (system AVALANCHE XT, Dr. Langer Medical, Waldkirch, Germany). A control group which underwent parotidectomies with only intermittent IONM was recruited from our records. Results: Half of the patients in our study group suffered from eFNP. All except one regained normal facial nerve function within 6 months of surgery. There was no significant difference regarding eFNP when compared to the control group without cIONM (p = 0.11). No statistically significant correlation between the stimulation threshold (p = 0.74) or the duration of nerve stimulation and eFNP was found (p = 0.51). Conclusion: We have demonstrated the safety of using the Saxophone®-electrode for cIONM of the facial nerve in parotid surgery. Future development of this method could enable the recognition of impending nerve injury and thus reduce eFNP. [ABSTRACT FROM AUTHOR]

Introduction: The retrograde approach (RP) to nerve identification is a method seldom used in parotid surgery. A systematic review comparing this method to the standard anterograde approach (AP) with respect to facial nerve palsy (FNP) does not currently exist.Methods: In a meta-analysis according to the PRISMA statement, eight publications, including one randomized controlled trial, were selected. The primary aim was to compare the temporary and permanent FNP resulting from the two dissection methods. Facial nerve function was graded according to the House-Brackmann Scale. The secondary goal was a comparison of the cut-suture times (CST), the volume of healthy tissue (VHT) dissected, the rates of postoperative hematoma (PH), and postoperative infection (PI).Results: Temporary FNP was noted in 18.2% in the RP group as well as in 34.4% in the AP group. Permanent FNP occurred in 0.9% RPs and 2.4% APs. According to the mixed-effect logistic regression model, there was no significant difference between the two groups in the pooled odds ratio (OR) for either temporary [OR 2.64, 95% confidence interval (CI) 0.97-7.21] or permanent FNP (OR 4.31, 95% CI 0.44-42.28). The CST was significantly shorter in the RP group (p = 0.005), with a significantly smaller VHT dissected (p < 0.0001). There were no differences regarding PH and PI.Conclusion: The RP is a safe procedure with no significant difference in FNP rates when compared to the AP and, considering the shorter CST and the lesser VHT resected in the RP, it is superior to the AP. Surgeons engaged in parotidectomy should be familiar with both methods of dissection. [ABSTRACT FROM AUTHOR]

Objective: Patients presenting with a cervical mass are common for head and neck specialists and present a diagnostic challenge against the backdrop of a wide variety of etiologies. The objective of the present study was to evaluate the significance of a mass in the supraclavicular fossa for etiology, diagnostic procedure, and therapy.Study Design: Individual retrospective cohort study.Methods: We reviewed the data of 211 consecutive cases (116 male, 95 female) with excisional biopsy or tumor removal of a supraclavicular mass.Results: In 202 of 211 cases, a biopsy was taken from a lymph node. In 182 biopsies, a malignant lymphadenopathy was found (117 metastases, 65 malignant lymphoma). The histologic findings of metastatic diseases were adenocarcinoma (48), followed by squamous cell carcinoma (22). The majority of primary carcinomas were located below the clavicle (94), in the lung (32), in the breast (29), and in the head and neck region (18). In the left supraclavicular fossa, only metastases of the genitourinary tract were significantly more frequent (16 of 17). In nonmalignant tumors (29), tuberculosis (11) was most prevalent. In 79% of biopsies, the neck mass was the first manifestation of the disease.Conclusion: The location of a cervical mass in the supraclavicular fossa provides a strong indication of malignancy. A biopsy is mandatory in the majority of patients presenting with a supraclavicular mass. In cases of metastatic disease, the location of a cervical mass helps identify the primary site. Histologic findings are essential for further diagnostic steps, therapy, and prognosis.Level Of Evidence: 4. Laryngoscope, 128:646-650, 2018. [ABSTRACT FROM AUTHOR]

Postoperative haemorrhage following tonsillectomy occurs in 5.98% of all cases with up to 10 deaths reported annually in Germany. When comparing tonsillectomy (TE) and tonsillotomy (TT), the same long-term frequency of ENT infections is displayed in children and young adults. However, taking postoperative haemorrhaging into account, TT is more favourable. Chronic tonsillitis is one of the most common indications for TE in the adult population; however, a histopathological characterization may reveal objective criteria and provide a foundation for routinely performing TT in adults too. Three essential parameters hyperplasia (HP), grade of inflammation (GOI) and activity of inflammation (AOI), which are responsible for, and associated with a clinically relevant disease were histopathologically examined in the tonsils of 100 adult patients with chronic recurrent tonsillitis. The parameters were analysed and compared separately in the pharyngeal and basal parts of the tonsils as well as in three sections (upper and lower pole of the tonsil, middle part) as this may influence the indication for TT. The comparison of the basal and pharyngeal portions displayed a significant difference in the GOI and the HP in all three sections: grade 2 HP as well as GOI were more commonly found in the basal than pharyngeal portions ( p > 0.001). AOI (grade 2) displayed the same properties in the middle section ( p < 0.002), but did not reach statistical significance in the cranial and caudal sections ( p = 0.107 and p = 0.186). An overabundance of grade 1 GOI, AOI, and HP was seen in the pharyngeal sections. The results show that two out of three relevant parameters that demonstrate histopathological changes in recurrent inflamed tonsils have a significantly stronger presence in the basal section of the tonsil as opposed to the pharyngeal section. The processes initiated by inflammation next to the surface responsible for a clinically relevant recurrent tonsillitis seem to cause stronger reactions in the deep follicular portion of the tonsils. [ABSTRACT FROM AUTHOR]

Objective: Anatomical study of surgical approaches of endoscopic minimally invasive thyroidectomy (eMIT) and transoral partial parathyroidectomy (TOPP) was conducted to evaluate their safety and feasibility. Material and methods: After performing an eMIT- and TOPP-procedure on fresh frozen human cadavers, a layer-by-layer dissection of the floor of the mouth and the anterior cervical region was carried out in five specimens. The blood vessels, nerves and muscles related to the surgical approach were exposed. Results: The anterior region of the neck can be reached through the midline of the mouth floor and the suprahyoid muscles. No important nerves and vessels were found in the approach of eMIT. TOPP set up the space at the dorsal side of the thyroid gland and adjacent to the trachea. The hypoglossal nerve and the lingual nerve as well as their accompanying blood vessels were anatomically related to the approach and could be injured during the procedure. The surgical space is much limited in TOPP (<20 mm in diameter) and current surgical instruments still did not match the requirement of this technique. Conclusions: This study demonstrated that the transoral approach of eMIT is anatomically safer and more feasible than that of TOPP. [ABSTRACT FROM AUTHOR]

Viral infections of the upper respiratory airways can lead to a delayed viral otitis media (VOM) caused by a diffusion of viruses/virus particles through the round window membrane and resulting in sensorineural hearing loss. The treatment of choice is immediate paracentesis, evacuation of all fluids from the middle ear cavity, and haemorrheological infusions. However, in some cases, persistent symptoms may be an indication for a surgical approach using mastoidectomy. In high-resolution computed tomography, an extended small-sized pneumatisation of the mastoid cells with complete shading was found in these non-responsive cases. Therefore, a direct means of inner ear affliction through weak parts of the labyrinthine bone may be hypothesised. Patients suffering from a toxic inner ear lesion (TIEL) following a common cold, treated over a 10-year period in a Tertiary Care Centre ( N = 52, 57 ears), were identified and the morphological characteristics of the temporal bones of affected patients were examined by means of high-resolution computed tomography (hrCT). The findings were compared with a matched control group of 64 normal ears (CONT). Measurements included the grade of pneumatisation, distances within the temporal bones and Hounsfield units (HU) at defined anatomical structures. In the TIEL group, we found a small-sized pneumatisation in 79.4 % and a medium-sized pneumatisation in 10.9 %, thus differing from the CONT group and the literature data. Thickness of the bone wall of the lateral semicircular canal (LSC) and distances within the aditus ad antrum were significantly reduced in the TIEL group. HU's were markedly lower in the TIEL group at the precochlea, the LSC, and dorsolateral to the promentia of the LSC. There was a correlation between the HU's at the prominentia of the LSC and the hearing loss ( p = 0.002). Persisting interosseous globuli, as described in 1897 by Paul Manasse, form an osseochondral network within the otic capsule and may be responsible for a direct means of toxic inner ear infection. The CT-morphometric results support this thesis. In the group of these patients (TIEL) a CT-scan and in non-responders to conservative treatment a surgical approach by mastoidectomy is recommended. [ABSTRACT FROM AUTHOR]

In the original publication of the article, first name and last names of all authors were swapped. [ABSTRACT FROM AUTHOR]