Bio-Inspired Magnetically Responsive Silicone Cilia: Fabrication Strategy and Interaction with Biological Mucus.

Cilia are biological structures essential to drive the mobility of secretions and maintain the proper function of the respiratory airways. However, this motile self-cleaning process is significantly compromised in the presence of silicone tracheal prosthesis, leading to biofilm growth and impeding effective treatment. To address this challenge and enhance the performance of these devices, we propose the fabrication of magnetic silicone cilia, with the prospect of their integration onto silicone prostheses. The present study presents a fabrication method based on magnetic self-assembly and assesses the interaction behavior of the cilia array with biological mucus. This protocol allows for the customization of cilia dimensions across a wide range of aspect ratios (from 6 to 85) and array densities (from 10 to 80 cilia/mm2) by adjusting the fabrication parameters, offering flexibility for adjustments according to their required characteristics. Furthermore, we evaluated the suitability of different cilia arrays for biomedical applications by analyzing their interaction with bullfrog mucus, simulating the airways environment. Our findings demonstrate that the fabricated cilia are mechanically resistant to the viscous fluid and still exhibit controlled movement under the influence of an external moving magnet. A correlation between cilia dimensions and mucus wettability profile suggests a potential role in facilitating mucus depuration, paving the way for further advancements aimed at enhancing the performance of silicone prostheses in clinical settings.

Bio-inspired magnetically responsive silicone cilia: fabrication strategy and interaction with biological mucus

Cilia are biological structures essential to drive the mobility of secretions and maintain the proper function of the respiratory airways. However, this motile self-cleaning process is significantly compromised in the presence of silicone tracheal prosthesis, leading to biofilm growth and impeding effective treatment. To address this challenge and enhance the performance of these devices, we propose the fabrication of magnetic silicone cilia, with the prospect of their integration onto silicone prostheses. The present study presents a fabrication method based on magnetic self-assembly and assesses the interaction behavior of the cilia array with biological mucus. This protocol allows for the customization of cilia dimensions across a wide range of aspect ratios (from 6 to 85) and array densities (from 10 to 80 cilia/mm2) by adjusting the fabrication parameters, offering flexibility for adjustments according to their required characteristics. Furthermore, we evaluated the suitability of different cilia arrays for biomedical applications by analyzing their interaction with bullfrog mucus, simulating the airways environment. Our findings demonstrate that the fabricated cilia are mechanically resistant to the viscous fluid and still exhibit controlled movement under the influence of an external moving magnet. A correlation between cilia dimensions and mucus wettability profile suggests a potential role in facilitating mucus depuration, paving the way for further advancements aimed at enhancing the performance of silicone prostheses in clinical settings.

Cold Atmospheric Helium Plasma in the Post-COVID-19 Era: A Promising Tool for the Disinfection of Silicone Endotracheal Prostheses.

Despite the excellent properties of silicone endotracheal prostheses, their main limitation is the formation of a polymicrobial biofilm on their surfaces. It can cause local inflammation, interfering with the local healing process and leading to further complications in the clinical scenario. The present study evaluated the inhibitory effect of cold atmospheric plasma (CAP) on multispecies biofilms grown on the silicone protheses' surfaces. In addition to silicone characterization before and after CAP exposure, CAP cytotoxicity on immortalized human bronchial epithelium cell line (BEAS-2B) was evaluated. The aging time test reported that CAP could temporarily change the silicone surface wetting characteristics from hydrophilic (80.5°) to highly hydrophilic (<5°). ATR-FTIR showed no significant alterations in the silicone surficial chemical composition after CAP exposure for 5 min. A significant log reduction in viable cells in monospecies biofilms (log CFU/mL) of C. albicans, S. aureus, and P. aeruginosa (0.636, 0.738, and 1.445, respectively) was detected after CAP exposure. Multispecies biofilms exposed to CAP showed significant viability reduction for C. albicans and S. aureus (1.385 and 0.831, respectively). The protocol was not cytotoxic to BEAS-2B. CAP can be a simple and effective method to delay multispecies biofilm formation inside the endotracheal prosthesis.

Cold atmospheric helium plasma in the Post-COVID-19 era: A promising tool for the disinfection of silicone endotracheal prostheses

ABSTRACT Despite the excellent properties of silicone endotracheal prostheses, their main limitation is the formation of a polymicrobial biofilm on their surfaces. It can cause local inflammation, interfering with the local healing process and leading to further complications in the clinical scenario. The present study evaluated the inhibitory effect of cold atmospheric plasma (CAP) on multispecies biofilms grown on the silicone protheses' surfaces. In addition to silicone characterization before and after CAP exposure, CAP cytotoxicity on immortalized human bronchial epithelium cell line (BEAS-2B) was evaluated. The aging time test reported that CAP could temporarily change the silicone surface wetting characteristics from hydrophilic (80.5°) to highly hydrophilic (<5°). ATR-FTIR showed no significant alterations in the silicone surficial chemical composition after CAP exposure for 5 min. A significant log reduction in viable cells in monospecies biofilms (log CFU/mL) of C. albicans, S. aureus, and P. aeruginosa (0.636, 0.738, and 1.445, respectively) was detected after CAP exposure. Multispecies biofilms exposed to CAP showed significant viability reduction for C. albicans and S. aureus (1.385 and 0.831, respectively). The protocol was not cytotoxic to BEAS-2B. CAP can be a simple and effective method to delay multispecies biofilm formation inside the endotracheal prosthesis.

Characteristics of postintubation dysphagia in ICU patients in the context of the COVID-19 outbreak: A report of 920 cases from a Brazilian reference center.

The purpose of this research was to identify risk factors that were independently related to the maintenance of a swallowing dysfunction in patients affected by critical COVID-19. We conducted a prospective observational cohort study of critical patients with COVID-19, who were admitted to a COVID-19 dedicated intensive care unit (ICU) and required prolonged orotracheal intubation (≥48 hours). Demographic and clinical data were collected at ICU admission and/or at hospital discharge or in-hospital death. Swallowing data was based on The Functional Oral Intake Scale (FOIS) and was collected at two distinct moments: initial swallowing assessment and at patient outcome. Patients were divided into two groups according to their FOIS level assigned on the last swallowing assessment: in-hospital resolved dysphagia-patients with FOIS levels 6 and 7; non-resolved dysphagia at hospital outcome-patients with FOIS levels 1 to 5. Nine hundred and twenty patients were included in our study. Results of the multivariate logistic regression model for the prediction of non-resolved dysphagia at hospital outcome in critical COVID-19 patients. indicated that increasing age (p = 0.002), severity at admission (p = 0.015), body mass index (p = 0.008), use of neuromuscular blockers (p = 0.028), presence of neurologic diseases (p = 0.038), presence of Diabetes Mellitus (p = 0.043) and lower FOIS levels on the initial swallowing assessment (p<0.001) were associated with higher chances of presenting dysphagia at hospital outcome. Critical patients with COVID-19 may experience post-acute COVID-19 dysphagia, indicating the need to prepare for the care/rehabilitation of these patients.

Decannulation: a retrospective cohort study of clinical and swallowing indicators of success.

OBJECTIVE: To investigate the clinical and swallowing indicators related to a successful decannulation process during the hospital stay. METHODS: A retrospective cohort clinical study. The study sample comprised a heterogeneous patient population who had submitted to a tracheostomy procedure in a tertiary hospital. Patients were divided into two groups (decannulated vs. non-decannulated) and compared not only in terms of demographic and clinical data but also the results of a swallowing assessment and intervention outcome. RESULTS: Sixty-four patients were included in the present study: 25 (39%) who had been successfully decannulated, and 39 (61%) who could not be decannulated. Between-group comparisons indicated that both groups presented similar clinical and demographic characteristics. The groups also presented similar swallowing assessment results prior to intervention. However, significant differences were observed regarding the time to begin swallowing rehabilitation. The decannulated group was assessed nine days earlier than the non-decannulated group. Other significant differences included the removal of the alternate feeding method (72.0% of decannulated patients vs. 5.1% of non-decannulated patients) and the reintroduction of oral feeding (96.0% of decannulated patients vs. 41.0% of non-decannulated patients) and functional swallowing level at patient disclosure. The non-decannulated patient group presented higher death rates at disclosure. CONCLUSION: The results of the present study indicated that the following parameters were associated with a successful decannulation process: early swallowing assessment, swallowing rehabilitation, and improvement in the swallowing functional level during the hospital stay. The maintenance of low swallowing functional levels was found to be negatively associated with successful decannulation.

Decannulation: a retrospective cohort study of clinical and swallowing indicators of success

Abstract Objective: To investigate the clinical and swallowing indicators related to a successful decannulation process during the hospital stay. Methods: A retrospective cohort clinical study. The study sample comprised a heterogeneous patient population who had submitted to a tracheostomy procedure in a tertiary hospital. Patients were divided into two groups (dec-annulated vs. non-decannulated) and compared not only in terms of demographic and clinical data but also the results of a swallowing assessment and intervention outcome. Results: Sixty-four patients were included in the present study: 25 (39%) who had been successfully decannulated, and 39 (61%) who could not be decannulated. Between-group comparisons indicated that both groups presented similar clinical and demographic characteristics. The groups also presented similar swallowing assessment results prior to intervention. However, significant differences were observed regarding the time to begin swallowing rehabilitation. The decannulated group was assessed nine days earlier than the non-decannulated group. Other significant differences included the removal of the alternate feeding method (72.0% of decannulated patients vs. 5.1% of non-decannulated patients) and the reintroduction of oral feeding (96.0% of decannulated patients vs. 41.0% of non-decannulated patients) and functional swallowing level at patient disclosure. The non-decannulated patient group presented higher death rates at disclosure. Conclusion: The results of the present study indicated that the following parameters were associated with a successful decannulation process: early swallowing assessment, swallowing rehabilitation, and improvement in the swallowing functional level during the hospital stay. The maintenance of low swallowing functional levels was found to be negatively associated with successful decannulation. HIGHLIGHTS Deccanulation indicators were investigated in patients who were submitted to a tracheostomy procedure. Early swallowing evaluation and rehabilitation were associated with a successful decannulation process. Low swallowing functional levels were negatively associated with the success of decannulation.

Treatment of tracheal stenosis with extracorporeal membrane oxygenation support in infants and newborns.

Tracheal stenosis in children is a challenge for the healthcare team, since it is a rare disease. Patients usually have other clinical comorbidities, mainly previous cardiac surgical interventions. This retrospective single-center study included infants with tracheal stenosis (congenital or acquired) operated between 2016 and 2020 on venoarterial extracorporeal membrane oxygenation (VA ECMO). Five patients were operated and the median age of detection of the tracheal disease was 3.7 months, and the median age at the operation was 5 months. All patients had associated cardiac anomalies. Four patients had congenital tracheal stenosis; two with associated pig bronchus. One patient had acquired subglottic stenosis with concomitant stenosis at the carina. After the operation, the patients were referred to ICU on ECMO with an open chest. Minor ECMO-related complications occurred in two patients (hemothorax and wound infection). All patients required endoscopic evaluation during the postoperative care; median of 3.2 procedures. Two patients are currently in follow-up and three have died. Slide tracheoplasty with VA-ECMO can be successfully performed in infants with prior cardiac surgery. Nevertheless, a difficult postoperative course should be anticipated, with possible prolonged ECMO use, readmissions, and higher morbidity and mortality than in children with tracheal stenosis alone.

EBUS-TBNA versus surgical mediastinoscopy for mediastinal lymph node staging in potentially operable non-small cell lung cancer: a systematic review and meta-analysis.

OBJECTIVE: Lung cancer (LC) is one of the leading causes of death worldwide. Accurate mediastinal staging is mandatory in order to assess prognosis and to select patients for surgical treatment. EBUS-TBNA is a minimally invasive procedure that allows sampling of mediastinal lymph nodes (LNs). Some studies have suggested that EBUS-TBNA is preferable to surgical mediastinoscopy for mediastinal staging of LC. The objective of this systematic review and meta-analysis was to compare EBUS-TBNA and mediastinoscopy in terms of their effectiveness for mediastinal LN staging in potentially operable non-small cell lung cancer (NSCLC). METHODS: This was a systematic review and meta-analysis, in which we searched various databases. We included studies comparing the accuracy of EBUS-TBNA with that of mediastinoscopy for mediastinal LN staging in patients with NSCLC. In the meta-analysis, we calculated sensitivity, specificity, positive likelihood ratios, and negative likelihood ratios. We also analyzed the risk difference for the reported complications associated with each procedure. RESULTS: The search identified 4,201 articles, 5 of which (with a combined total of 532 patients) were selected for inclusion in the meta-analysis. There were no statistically significant differences between EBUS-TBNA and mediastinoscopy in terms of the sensitivity (81% vs. 75%), specificity (100% for both), positive likelihood ratio (101.03 vs. 95.70), or negative likelihood ratio (0.21 vs. 0.23). The area under the summary ROC curve was 0.9881 and 0.9895 for EBUS-TBNA and mediastinoscopy, respectively. Although the number of complications was higher for mediastinoscopy, the difference was not significant (risk difference: -0.03; 95% CI: -0.07 to 0.01; I2 = 76%). CONCLUSIONS: EBUS-TBNA and mediastinoscopy produced similar results for mediastinal staging of NSCLC. EBUS-TBNA can be the procedure of first choice for LN staging in patients with NSCLC.

Early complications in flexible bronchoscopy at a university hospital.

OBJECTIVE: To analyze the complications related to flexible bronchoscopy (FB) and its collection procedures in outpatients and inpatients with various lung and airway diseases treated at a university hospital. METHODS: This was a retrospective analysis of complications occurring during or within 2 h after FB performed between January of 2012 and December of 2013, as recorded in the database of the respiratory endoscopy department of a hospital complex in the city of São Paulo, Brazil. RESULTS: We analyzed 3,473 FBs. Complications occurred in 185 procedures (5.3%): moderate to severe bleeding, in 2.2%; pneumothorax, in 0.7%; severe bronchospasm, in 0.8%; general complications (hypoxemia, psychomotor agitation, arrhythmias, vomiting, or hypotension), in 1.6%; and cardiopulmonary arrest, in 0.03%. There were no deaths related to the procedures. Specifically, among the 1,728 patients undergoing biopsy, bronchial brushing, or fine-needle aspiration biopsy, bleeding occurred in 75 (4.3%). Among the 1,191 patients undergoing transbronchial biopsy, severe pneumothorax (requiring chest tube drainage) occurred in 24 (2.0%). CONCLUSIONS: In our patient sample, FB proved to be a safe method with a low rate of complications. Appropriate continuing training of specialist doctors and nursing staff, as well as the development of standardized care protocols, are important for maintaining those standards.

Impact of gastroesophageal reflux in the pathogenesis of tracheal stenosis.

Benign airway stenosis is a multifactorial and heterogeneous disease often occurring after tracheal intubation. Despite the frequent finding of pathological gastroesophageal reflux (GER) in benign tracheal stenosis, the cause-and-effect relationship between these two entities and its impact on the outcome of the stenosis itself have not been established. The altered ventilatory dynamics caused by an increased thoracoabdominal pressure gradient in such patients has been proposed as a central cause. The presence of GER in a setting of microaspiration can also induce changes in the local collagen proliferation response, as well as in the local microbiome of the tracheal stenosis site, which may potentially cause and enhance the harm imposed to the already diseased tracheal wall. Diagnosis of GER remains underestimated in the general population, thus making its accurate detection and treatment in central airway stenosis a matter of investigation. The high prevalence of GER in tracheal stenosis patients often occurs in the absence of typical upper digestive signs and symptoms, therefore requiring an objective assessment using a 24-hour ambulatory esophageal pH/impedance study that has shown abnormal results in more than half the patients. The impact of the treatment of GER in patients with benign tracheal has been scarcely reported. Our group showed recently that the surgical control of GER through laparoscopic fundoplication in selected patients with tracheal stenosis can improve substantially the chance of resolution of the tracheal stenosis as opposed to the medical management with high dose proton pump inhibitors. This chapter describes the impact of GER in the pathogenesis of tracheal stenosis with a focus on its mechanisms, diagnosis and treatment strategy.

An in vivo image acquisition system for the evaluation of tracheal mechanics in rats.

Mechanical evaluation of tracheal grafts is of great relevance for transplant research. Although there are some publications demonstrating different techniques of tracheal mechanical evaluation, there is still no definitive or preferred protocol available. Here, we present a simple image processing acquisition system that can be used for in vivo experiments. Six male Wistar rats were submitted to orotracheal intubation and a longitudinal incision was made to expose the trachea. Images of tracheae were acquired from a video camera in different scenarios of bronchoconstriction using methacholine (MCh) (Basal, PBS, MCh 30 µg/kg, MCh 300 µg/kg, and postmetabolized) during imposed-inspiration and imposed-expiration. The area variation ratio (the ratio between areas during expiration vs. inspiration) was 1.1× for the Basal group, while the ratio for MCh 300 µg/kg was 6.5×. The area variation of imaged tracheae was statistically significant at the dose of MCh 300 µg/kg for imposed-inspiration versus imposed-expiration (P = .002). Likewise, elastance data of respiratory mechanics indicated a statistically significant difference at the dose of MCh 300 µg/kg for imposed-inspiration versus imposed-expiration (P = .026). Our image processing analysis protocol presented corresponding behavior when compared to mechanical parameters of the respiratory system. In addition, our image acquisition system was able to highlight the differences between imposed-inspiration and imposed-expiration. Image analysis of the tracheal area variation seems to be in agreement with the elastance of the respiratory system. Taken together, these observations may help future studies of tracheal transplantation for in situ assessment of graft patency.

Posterior laryngofissure using a surgical contact diode laser: an experimental feasibility study.

To evaluate the feasibility of a 980-nm contact diode laser (CDL) as a method for creating a posterior laryngofissure in live pigs. Twenty-eight Landrace pigs (15-20 kg) were anesthetized, intubated, ventilated, and submitted to a cervical tracheostomy. An anterior and posterior midline longitudinal laryngofissure incision was created according to randomization-control (n = 4), posterior laryngofissure with a scalpel blade; electrocautery (n = 12), posterior laryngofissure by electrocautery (10, 15, 20, 25 W powers); CDL (n = 12), posterior laryngofissure by the CDL (10, 15, 20, 25 W peak powers in pulsed mode). Larynx and proximal trachea were excised, prepared for histopathology, and digital morphometric analysis. Measurements in and within each group were analyzed (Kruskal-Wallis and Dunn test) with a level of significance of p < 0.05. Incision width was not different between the groups, as well as in the powers used in CDL (p = 0.161) and electrocautery group (p = 0.319). The depth of the incisions was smaller in the Laser group compared to control (p = 0.007), and in the electrocautery compared to control (p = 0.026). Incision area was smaller in CDL compared with the control (p = 0.027), and not different between laser and electrocautery groups (p = 0.199). The lateral thermal damage produced by electrocautery was the largest, with a significant difference between laser and electrocautery (p = 0.018), and between electrocautery and control (p = 0.004), whereas the comparison between laser and control showed no significant differences (p = 0.588). The posterior laryngofissure incision using a 980-nm CDL is feasible resulting in smaller incisional area and less lateral thermal damage.

Health-related quality of life evaluation in patients with non-surgical benign tracheal stenosis.

BACKGROUND: The primary objective of the study was to evaluate the health-related quality of life (HRQL) of patients with benign post-intubation tracheal stenosis considered as unfit for surgical treatment. Secondary objectives were: (I) to determine if clinical variables (gender, age, total treatment time, and type of tracheal device) could influence HRQL and (II) to compare the results with a normal standardized population. METHODS: Prospective study between August-2014 and December-2016 including patients with tracheal stenosis treated with silicone stents, T-Tubes or tracheostomy. Candidates to airway resection and reconstruction were excluded from the analysis. HRQL was assessed with the SF-36 Health Questionnaire. Backward stepwise regression model analyzed the influence of clinical variables on the SF-36 domains and component summaries. Norm-based results were compared with normative data. Alpha error was 5%. RESULTS: Ninety-three patients (62M/31F; mean age 38±14 years) were included. Mean overall HRQL in all 8 SF-36 domains was poor. Lowest scores were in the role physical (mean 31.7±38), bodily pain (mean 39.2±35), and role emotional domain (mean 48.7±40). The physical component summary (PCS) was more affected than the mental (P<0.001). Norm-based results indicated that most domains and both physical and mental summaries were below the mean for the USA normative population. Total stenting time significantly influenced the physical (P=0.001) and mental component summaries (P=0.001). CONCLUSIONS: Quality of life of patients with benign tracheal stenosis is severely impaired, and norm-based results indicate that the HRQL is below normative data. Physical and mental discomfort seems to be attenuated by total treatment time.

Surgery for intrathoracic tracheoesophageal and bronchoesophageal fistula.

Benign tracheoesophageal fistula (TEF) results from an abnormal communication between the posterior wall of the trachea or bronchi and the adjacent anterior wall of the esophagus. It can be acquired or congenital. The onset of the TEF has a negative impact on the patient's health status and quality of life because of swallowing difficulties, recurrent aspiration pneumonia, and severe weight loss. Several acquired conditions may cause TEF. The most frequent is prolonged orotracheal intubation (75% of the cases). Usually, there is an erosion of the tracheal and esophageal wall by the continuous pressure between the endotracheal tube and the esophageal wall; particularly in the presence of a nasogastric or feeding tube within the esophageal lumen. Furthermore, tracheal stenosis is often associated, and adds complexity to the disease. Preparation for the surgical procedure may take weeks or even months. It includes definitive weaning from mechanical ventilation, treatment of respiratory infection, physiotherapy, and correction of malnutrition through enteral feeding. Surgical repair of a TEF is an elective procedure. It consists of division of the fistula, suture of the esophagus and trachea and protection of the suture lines with a buttressed muscle flap. TEF repair is a complex and challenging procedure, thus, high morbidity and mortality are expected. Nonetheless, surgical management yields excellent long-term results, and it should be considered the first-line treatment for this condition. Definitive fistula closure occurs in about 90-95% of the cases.

Prophylaxis and Treatment of Complications After Tracheal Resection.

Tracheal resections are major surgical procedures with a complication rate as high as 44%. Early detection of complications followed by a structured and expedited course of action is critical for achieving a successful outcome. The prevention of complications after tracheal resection starts with a correct indication for resection. A thorough preoperative evaluation, meticulous surgical technique, and good postoperative care in a center that performs airway surgery routinely are important factors for achieving good results.