Treatment of Laryngeal and Tracheal Stenosis: Cooperative Treatment With Our Pulmonary Interventionalist Colleagues.

OBJECTIVES/HYPOTHESIS: We will describe the treatment of patients with subglottic and tracheal stenosis using instruments and techniques utilized by otolaryngologists and interventional pulmonologists (IP), with a focus on IP-favored approaches that may be less familiar to otolaryngologists. We will present two cases that were treated cooperatively by otolaryngology and IP and will highlight the advantages of certain techniques. STUDY DESIGN: Case series METHODS: This is a case-based presentation highlighting procedures done cooperatively by otolaryngology and IP. Instruments and techniques typically utilized by each specialty will be presented, including rigid and flexible bronchoscopy, laser, balloon dilation, medical adjuncts, fiberoptic electrocautery, fiberoptic cryoablation, and fiberoptic argon plasma coagulation. Patient outcomes for these techniques will also be discussed based on the current literature. RESULTS AND CONCLUSIONS: A dichotomy exists in the approaches typically utilized by otolaryngology and IP to address laryngotracheal stenosis. Our IP colleagues utilize techniques via a flexible bronchoscope that are often not considered in a typical otolaryngology practice. We discussed these techniques to educate otolaryngologists who may be looking to contribute to their armamentarium, as current literature suggests promising patient outcomes. Ultimately, a team approach to these often-complex patients can result in excellent outcomes.

Preparation of subcooled liquid argon and test of its cooling ability.

Subcooled liquid nitrogen and nitrogen slush are often considered for high-speed cooling, but their preparation and maintenance are not easy. To address this issue, a unique device was designed to prepare subcooled liquid argon (SLA) using liquid nitrogen (LN). The cooling process was mathematically modeled to predict the preparation time. If the interlayer space between LN and liquid argon is filled with nitrogen gas, liquid argon could be cooled to 3.5 K subcooling within 1 h. If the interlayer is filled with air, 2 h are required to achieve the same subcooled state. An additional 1000 mL of LN was required for the preparation of 600 mL of 3.5 K SLA. The cooling tests of 3 µL microdroplets in 3 mm-6 mm capillary quartz tubes were duplicated to evaluate the potential of SLA. It was found that the cooling rate of microdroplet in the 3.5 K subcooled SLA is very close to that in the 3 K subcooled LN, higher than that in the saturated LN. The convenience of preparation and maintenance of SLA can make it good choice of cryogen for cryopreservation of biomaterials.

Effects of Argon in the Acute Phase of Subarachnoid Hemorrhage in an Endovascular Perforation Model in Rats.

BACKGROUND: Subarachnoid hemorrhage (SAH) is a devastating disease with high morbidity and mortality. Neuroprotective effects of the noble gas argon have been shown in animal models of ischemia. The aim of this study was to investigate the effects of argon in the immediate early phase of SAH in a rat model. METHODS: A total of 19 male Wistar rats were randomly assigned to three treatment groups. SAH was induced using a endovascular filament perforation model. Cerebral blood flow, mean arterial blood pressure (MAP), and body temperature were measured continuously. Group A received 2 h of ventilation by 50% argon/50% O2 (n = 7) immediately following SAH. Group B underwent a sham operation and was also ventilated by 50% argon/50% O2 (n = 6). Group C underwent SAH and 50% O2/50% N2 ventilation (n = 6). Preoperative and postoperative neurological and behavioral testing were performed. Histology and immunohistochemistry were used to evaluate the extent of brain injury and vasospasm. RESULTS: The cerebral blood flow dropped in both treatment groups after SAH induction (SAH, 63.0 ± 11.6% of baseline; SAH + argon, 80.2 ± 8.2% of baseline). During SAH, MAP increased (135.2 ± 10.5%) compared with baseline values (85.8 ± 26.0 mm Hg) and normalized thereafter. MAP in both groups showed no significant differences (p = 0.3123). Immunohistochemical staining for neuronal nuclear antigen demonstrated a decrease of hippocampal immunoreactivity after SAH in the cornu ammonis region (CA) 1-3 compared with baseline hippocampal immunoreactivity (p = 0.0127). Animals in the argon-ventilated group showed less neuronal loss compared with untreated SAH animals (p < 0.0001). Ionized calcium-binding adaptor molecule 1 staining showed a decreased accumulation after SAH + argon (CA1, 2.57 ± 2.35%; CA2, 1.89 ± 1.89%; CA3, 2.19 ± 1.99%; DG, 2.6 ± 2.24%) compared with untreated SAH animals (CA1, 5.48 ± 2.39%; CA2, 4.85 ± 4.06%; CA3, 4.22 ± 3.01%; dentate gyrus (DG), 3.82 ± 3.23%; p = 0.0007). The neuroscore assessment revealed no treatment benefit after SAH compared with baseline (p = 0.385). CONCLUSION: In the present study, neuroprotective effects of argon occurred early after SAH. Because neurological deterioration was similar in the preadministration and absence of argon, it remains uncertain if neuroprotective effects translate in improved outcome over time.

Hybrid argon plasma coagulation for the treatment of Barrett's esophagus: A prospective, multicenter study.

BACKGROUND: The incidence of Barrett's esophagus (BE) in China is lower compared to the Western populations. Hence, studies conducted in the Chinese population has been limited. The current treatment options available for BE treatment includes argon plasma coagulation (APC), radiofrequency ablation and cryoablation, all with varying degrees of success. AIM: To determine the efficacy and safety of HybridAPC in the treatment of BE. METHODS: The study cohort consisted of patients with BE who underwent HybridAPC ablation treatment. These procedures were performed by seven endoscopists from different tertiary hospitals. The duration of the procedure, curative rate, complications and recurrent rate by 1-year follow-up were recorded. RESULTS: Eighty individuals were enrolled for treatment from July 2017 to June 2020, comprising of 39 males and 41 females with a median age of 54 years (range, 30 to 83 years). The technical success rate of HybridAPC was 100% and the overall curative rate was 98.15%. No severe complications occurred during the operation. BE cases were classified as short-segment BE and long-segment BE. Patients with short-segment BE were all considered cured without complications. Thirty-six patients completed the one-year follow-up without recurrence. Twenty-four percent had mild dysplasia which were all resolved with one post-procedural treatment. The mean duration of the procedure was 10.94 ± 6.52 min. CONCLUSION: Treatment of BE with HybridAPC was found to be a simple and quick procedure that is safe and effective during the short-term follow-up, especially in cases of short-segment BE. This technique could be considered as a feasible alternative ablation therapy for BE.

Efficient Transformation of Water Vapor into Hydrogen by Dielectric Barrier Discharge Loaded with Bamboo Carbon Bed Structured by Fibrous Material.

A new method of efficiently transforming water vapor into hydrogen was investigated by dielectric barrier discharge (DBD) loaded with bamboo carbon bed structured by fibrous material in an argon medium. Hydrogen productivity was measured in three different reactors: a non-loaded DBD (N-DBD), a bamboo carbon (BC) bed DBD (BC-DBD), and a quartz wool (QW)-loaded BC DBD (QC-DBD). The effects of the quality ratio of BC to QW and relative humidity on hydrogen productivity were also investigated in QC-DBD at various flow rates. The reaction process and mechanism were analyzed by scanning electron microscopy, X-ray photoelectron spectroscopy, N2 physisorption experiments, infrared spectroscopy, and optical emission spectroscopy. A new reaction pathway was developed by loading BC into the fibrous structured material to activate the reaction molecules and capture the O-containing groups in the DBD reactor. A hydrogen productivity of 17.3 g/kWh was achieved at an applied voltage of 5 kV, flow rate of 4 L/min, and 100% relative humidity (RH) in the QC-DBD with a quality ratio of BC to QW of 3.0.

Comparative clinical feasibility of antireflux mucosectomy and antireflux mucosal ablation in the management of gastroesophageal reflux disease: Retrospective cohort study.

OBJECTIVES: No definitive treatment has been established for refractory gastroesophageal reflux disease (GERD). Antireflux mucosectomy (ARMS) and antireflux mucosal ablation (ARMA) using argon plasma coagulation are promising methods. However, no study has compared these two. This study compared the efficacy and safety of the two procedures. METHODS: This multicenter, retrospective, observational study included 274 patients; 96 and 178 patients underwent ARMA and ARMS, respectively. The primary outcome was subjective symptom improvement based on GERD questionnaire (GERDQ) scores. The secondary outcomes included changes in the presence of Barrett's esophagus, Los Angeles grade for reflux esophagitis, flap valve grade, and proton pump inhibitor withdrawal rates. RESULTS: The ARMS group had higher baseline GERDQ scores (10.0 vs. 8.0, P < 0.001) and a greater median postprocedure improvement than the ARMA group (4.0 vs. 2.0, P = 0.002), and even after propensity score matching adjustment, these findings remained. ARMS significantly improved reflux esophagitis compared with ARMA, with notable changes in Los Angeles grade (P < 0.001) and flap valve grade scores (P < 0.001). Improvement in Barrett's esophagus was comparable between the groups (P = 0.337), with resolution rates of 94.7% and 77.8% in the ARMS and ARMA groups, respectively. Compared with the ARMA group, the ARMS group experienced higher bleeding rates (P = 0.034), comparable stricture rates (P = 0.957), and more proton pump inhibitor withdrawals (P = 0.008). CONCLUSIONS: Both ARMS and ARMA showed improvements in GERDQ scores, endoscopic esophagitis, flap valve grade, and the presence of Barrett's esophagus after the procedures. However, ARMS demonstrated better outcomes than ARMA in terms of both subjective and objective indicators.

Effects of plasma surface treatment on the bond strength of zirconia with an adhesive resin luting agent.

The purpose of this study was to evaluate the effect of the atmospheric pressure plasma treatment as a surface treatment method on the contact angle and shear bond strength (SBS) of zirconia ceramics and the failure mode between the self-adhesive resin luting agent and zirconia. The zirconia specimens were divided into eight groups based on the surface treatment method: alumina blasting, air plasma, argon plasma (AP), Katana cleaner, ozonated water, ozonated water+AP, Katana cleaner+AP, and tap water+AP. The contact angles, SBS, and fracture modes were tested. AP treatment significantly reduced the contact angle (p<0.0001). The combination of AP and other cleaning methods showed a higher bond strength and more mixed fractures. Our findings indicate that using atmospheric pressure plasma with argon gas, combined with other cleaning methods, results in a stronger bond than when using alumina blasting alone.

Management of circumscribed choroidal hemangioma at a tertiary care center.

PURPOSE: To review long-term outcomes of circumscribed choroidal hemangioma (CCH). METHODS: Hospital charts of all CCH cases diagnosed from 2008 to 2019 were retrospectively reviewed. RESULTS: All 172 patients were managed with either observation, transpupillary thermotherapy, argon laser photocoagulation, photodynamic therapy, plaque brachytherapy or stereotactic radiosurgery. The most common 3 modes of management were clinical observation (30.2%), transpupillary thermotherapy (52.9%) and argon laser photocoagulation (8.7%). Median follow-up time was 10 months (range: 3, 160). Anatomical outcomes were stable in 87.1% of observation group and improved in 60.5% of thermotherapy group. Quantified optical coherence tomography angiography findings showed statistical differences in vascular and perfusion densities in fellow eyes of hemangioma patients. CONCLUSION: Circumscribed choroidal hemangioma can be treated in various ways. Transpupillary thermotherapy is an anatomically effective treatment in selected cases. The diagnosis of CCH may have vascular implications in fellow eyes of the patients.

Gastric Antral Vascular Ectasia: Resolution of Bleeding and Stabilization of Hematocrit Following Orthotopic Liver Transplantation.

Gastric Antral Vascular Ectasia (GAVE) is an uncommon cause of chronic gastrointestinal bleeding and iron deficiency anemia in the geriatric population. It is often associated with cirrhosis of the liver and is hypothesized to result from synthetic liver dysfunction. Treatment options include argon plasma coagulation, endoscopic band ligation, and radiofrequency ablation. An orthotopic liver transplant may be effective for patients with advanced liver disease. In this case report, we describe a 60-year-old woman with a history of cirrhosis secondary to nonalcohol-related steatohepatitis (NASH) and GAVE syndrome who presented with abdominal pain and melena. She had multiple prior episodes of gastrointestinal bleeding, leading to long-term transfusion dependency. An urgent esophagogastroduodenoscopy revealed the presence of GAVE with active bleeding. The patient was supported with blood transfusions and transferred to a transplant center, where she underwent orthotopic liver transplantation. Following the transplantation, her hemoglobin levels improved and remained stable. She was no longer noted to require any further blood transfusions during outpatient follow-up visits. This case report substantiates the role of synthetic liver dysfunction in the development of GAVE. Also, it suggests that patients with advanced cirrhosis and refractory GAVE may benefit from liver transplantation as a potential treatment option.

Efficacy of surgical treatments for the management of solitary rectal ulcer syndrome: a network meta-analysis.

AIM: Solitary rectal ulcer syndrome (SRUS) is a benign and poorly understood disorder with complex management. Typical symptoms include straining during defaecation, rectal bleeding, tenesmus, mucoid secretion, anal pain and a sense of incomplete evacuation. Diagnosis is based on characteristic clinical symptoms and endoscopic/histological findings. Several treatments have been reported in the literature with variable ulcer healing rates. This study aimed to evaluate the efficacy of different treatments for SRUS. MATERIALS AND METHODS: A systematic review and network meta-analysis were performed according to the PRISMA guidelines. Studies in English, French and Spanish languages were included. Papers written in other languages were excluded. Other exclusion criteria were reviews, case reports or clinical series enrolling less than five patients, study duplications, no clinical data of interest and no article available. A systematic literature search was conducted from January 2000 to March 2024 using the following databases: PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, and Scopus. The biases of the studies were assessed using the Newcastle-Ottawa scale or the Jadad scale when appropriate. Types of treatment and their efficacy for the cure of SRUS were collected and critically assessed. The study's primary outcome was to estimate the rate of patients with ulcer healing. RESULTS: A total of 22 studies with 911 patients (men 361, women 550) diagnosed with SRUS were analysed in the final meta-analysis. The pooled effect estimates of treatment efficacy revealed that surgery showed the highest ulcer healing rate (70.5%; 95% CI 0.57-0.83). Surgery was superior in the cure of ulcers with respect to medical therapies and biofeedback (OR 0.09 and OR 0.14). CONCLUSION: Solitary rectal ulcer syndrome is a challenging clinical entity to manage. Proficient results have been reported with the surgical approach, suggesting its positive role in cases refractory to medical and biofeedback therapy. Further studies in homogeneous populations are required to evaluate the efficacy of surgery in this setting. (PROSPERO registration number CRD42022331422).

Pulmonary Endobronchial Hamartoma Presenting With Post-obstructive Pneumonia.

Pulmonary hamartomas (PH) are rare but are the most common benign tumors found in the lungs. They are slow-growing and are usually found incidentally on chest imaging during the sixth decade of life. Approximately 10% of pulmonary hamartomas are endobronchial. Rarely, pulmonary hamartomas can cause a spectrum of pulmonary symptoms depending on their size and location. We present a case of endobronchial hamartoma causing airway obstruction and recurrent post-obstructive pneumonia.

Seeing Beyond the Expected: An Uncommon Case of Plateau Iris Syndrome in the Outpatient Setting.

Patients presenting with elevated intraocular pressures (IOPs) refractory to laser peripheral iridotomy should be suspected to have plateau iris syndrome (PIS). We present an uncommonly seen case of a 59-year-old female who presented with blurred vision, left-sided head pain, and IOPs Oculus Uterque (OU). Despite medical and laser peripheral iridotomy, left eye pain and elevated IOPs persisted, which led to a suspected diagnosis of PIS. The patient was subsequently treated by a glaucoma specialist who performed argon laser iridoplasty. Following this procedure alongside appropriate pharmacologic maintenance treatment, the patient's symptoms and elevated IOPs were resolved. With proper management, irreversible blindness can be prevented in PIS.

Acute Angle Closure in an 18-Year-Old Due to Plateau Iris.

In this case report, we describe a rare case of acute angle closure in an 18-year-old African-American female, attributed to plateau iris. The patient had no significant medical or ocular history and presented with high right-eye pressure, headache, and blurred vision. Ocular examination revealed findings consistent with acute angle closure, with gonioscopy confirming superior iris insertion anterior to Schwalbe's line and a "double hump" sign. Ultrasound biomicroscopy confirmed plateau iris. Treatment involved pharmacological management and bilateral peripheral laser iridoplasty. This case underscores the importance of considering plateau iris syndrome in the differential diagnosis of acute angle closure, even in younger patients, and highlights the role of early diagnosis and appropriate intervention in preventing vision loss.

Effectiveness and Safety of Argon Plasma Coagulation in Patients with Haemoptysis Caused by an Endobronchial Malignancy.

INTRODUCTION: Patients with central neoplasms and haemoptysis show low survival rates. Symptom control without recurrence 48 h after bronchoscopic interventions may improve the prognosis of these patients. Bronchoscopic argon plasma coagulation (APC) is a useful technique for endobronchial management of haemoptysis in patients with central malignancies. Nevertheless, limited data are available in the literature on its efficacy and safety and the main predictors of success are still unclear. METHODS: An observational, prospective, single-centre cohort study was carried out to assess the efficacy (i.e., immediate bleeding cessation without recurrence during the following 48 h) of bronchoscopic APC in the treatment of patients with haemoptysis caused by endobronchial malignancies and the main predictors of success. RESULTS: A total of 76 patients with median age 75 years (interquartile range: 65-79) were enrolled. 67 (88.2%) patients had bleeding cessation without recurrence 48 h after bronchoscopic APC. A low rate of non-serious adverse events (5.3%) was recorded and a low (7.6%) recurrence rate of haemoptysis at 3.5 months after the procedure was also shown. No clinical, demographic and endoscopic variables related to a successful procedure at 48 h were found. CONCLUSION: This study demonstrates that bronchoscopic APC is an effective procedure in the treatment of patients with haemoptysis caused by endobronchial malignancies, regardless of the clinical characteristics of the patients, the endoscopic and histological features of the neoplasm and the severity of the symptom. Furthermore, it shows a low rate of complications and long-term efficacy in bleeding control.

Improvement of mechanical performance on zirconium dioxide nanoparticle synthesized magnesium alloy nano composite.

With excellent mechanical properties and distinct solidification, the AZ31B series magnesium alloy has great potential for targeting engineering applications and synthesized via die casting process found a drawback on oxidation results porosity and reduced mechanical properties. Here, the magnesium alloy AZ31B series nanocomposite was synthesized with varied weight percentages of zirconium dioxide nanoparticles through a liquid metallurgy route with an applied stir speed of 200 rpm under an argon nature. With the help of a scanning electron microscope, the distribution of particles in the composite surface was found to be homogenous and void-free surface, which output results in less percentage of porosity (<1 %), and the composite contained 6 wt% ZrO2 offers superior yield strength (212 ± 3 MPa), tensile strength (278 ± 2 MPa), and impact strength of 16.4 ± 0.4 J/mm2. In addition, 8 wt% ZrO2 blended composite showed the maximum microhardness value (78.3 ± 1 HV). The best-enhanced result of NC3 (AZ31B/6 wt% ZrO2) is suggested for lightweight to high-strength structural applications.

Audiometric and Vestibular Function after Classic and Reverse Stapedotomy.

Background and Objectives: Besides classical stapedotomy, reverse stapedotomy has been used for many years in the management of otosclerosis. Our study aims to investigate whether reversing the surgical steps in stapedotomy impacts vestibular function and hearing improvement. Materials and Methods: A cohort of 123 patients underwent either classic or reverse stapedotomy procedures utilizing a fiber-optic argon laser. Audiological assessments, following the guidelines of the Committee on Hearing and Equilibrium, were conducted, including pure tone average, air-bone (AB) gap, overclosure, and AB gap closure. Vestibular evaluation involved pre- and postoperative comparison of rotatory test parameters, including frequency, amplitude, and slow phase velocity of nystagmus. Results: The study demonstrated an overall median overclosure of 3.3 (3.3, 5.0) dB and a mean AB gap closure of 20.3 ± 8.8 dB. Postoperative median AB gap was 7.5 (7.5, 11.3) dB in the reverse stapedotomy group and 10.0 (10.0, 12.5) dB in the classic stapedotomy group. While overclosure and AB gap closure were marginally superior in the reverse stapedotomy group, these differences did not reach statistical significance. No significant disparities were observed in the frequency, slow phase velocity, or amplitude of nystagmus in the rotational test. Conclusions: Although not always possible, reverse stapedotomy proved to be a safe surgical technique regarding postoperative outcomes. Its adoption may mitigate risks associated with floating footplate, sensorineural hearing loss, and incus luxation/subluxation, while facilitating the learning curve for less experienced ear surgeons.

Setting Plasma Immersion Ion Implantation of Ar+ Parameters towards Electroforming-Free and Self-Compliance HfO2-Based Memristive Structures.

Memristive structures are among the most promising options to be components of neuromorphic devices. However, the formation of HfO2-based devices in crossbar arrays requires considerable time since electroforming is a single stochastic operation. In this study, we investigate how Ar+ plasma immersion ion implantation (PI) affects the Pt/HfO2 (4 nm)/HfOXNY (3 nm)/TaN electroforming voltage. The advantage of PI is the simultaneous and uniform processing of the entire wafer. It is thought that Ar+ implantation causes defects to the oxide matrix, with the majority of the oxygen anions being shifted in the direction of the TaN electrode. We demonstrate that it is feasible to reduce the electroforming voltages from 7.1 V to values less than 3 V by carefully selecting the implantation energy. A considerable decrease in the electroforming voltage was achievable at an implantation energy that provided the dispersion of recoils over the whole thickness of the oxide without significantly affecting the HfOXNY/TaN interface. At the same time, Ar+ PI at higher and lower energies did not produce the same significant decrease in the electroforming voltage. It is also possible to obtain self-compliance of current in the structure during electroforming after PI with energy less than 2 keV.

Treatment with inhaled Argon: a systematic review of pre-clinical and clinical studies with meta-analysis on neuroprotective effect.

BACKGROUND: Argon (Ar) has been proposed as a potential therapeutic agent in multiple clinical conditions, specifically in organ protection. However, conflicting data on pre-clinical models, together with a great variability in Ar administration protocols and outcome assessments, have been reported. The aim of this study was to review evidence on treatment with Ar, with an extensive investigation on its neuroprotective effect, and to summarise all tested administration protocols. METHODS: Using the PubMed database, all existing pre-clinical and clinical studies on the treatment with Ar were systematically reviewed (registration: https://doi.org/10.17605/OSF.IO/7983D). Study titles and abstracts were screened, extracting data from relevant studies post full-text review. Exclusion criteria included absence of full text and non-English language. Furthermore, meta-analysis was also performed to assess Ar potential as neuroprotectant agent in different clinical conditions: cardiac arrest, traumatic brain injury, ischemic stroke, perinatal hypoxic-ischemic encephalopathy, subarachnoid haemorrhage. Standardised mean differences for neurological, cognitive and locomotor, histological, and physiological measures were evaluated, through appropriate tests, clinical, and laboratory variables. In vivo studies were evaluated for risk of bias using the Systematic Review Center for Laboratory Animal Experimentation tool, while in vitro studies underwent assessment with a tool developed by the Office of Health Assessment and Translation. FINDINGS: The systematic review detected 60 experimental studies (16 in vitro, 7 ex vivo, 31 in vivo, 6 with both in vitro and in vivo) investigating the role of Ar. Only one clinical study was found. Data from six in vitro and nineteen in vivo studies were included in the meta-analyses. In pre-clinical models, Ar administration resulted in improved neurological, cognitive and locomotor, and histological outcomes without any change in physiological parameters (i.e., absence of adverse events). INTERPRETATION: This systematic review and meta-analysis based on experimental studies supports the neuroprotective effect of Ar, thus providing a rationale for potential translation of Ar treatment in humans. Despite adherence to established guidelines and methodologies, limitations in data availability prevented further analyses to investigate potential sources of heterogeneity due to study design. FUNDING: This study was funded in part by Italian Ministry of Health-Current researchIRCCS and by Ministero della Salute Italiano, Ricerca Finalizzata, project no. RF 2019-12371416.