First real-time imaging of bronchoscopic lung volume reduction by electrical impedance tomography.

BACKGROUND: Bronchoscopic lung volume reduction (BLVR) with one-way endobronchial valves (EBV) has better outcomes when the target lobe has poor collateral ventilation, resulting in complete lobe atelectasis. High-inspired oxygen fraction (FIO2) promotes atelectasis through faster gas absorption after airway occlusion, but its application during BLVR with EBV has been poorly understood. We aimed to investigate the real-time effects of FIO2 on regional lung volumes and regional ventilation/perfusion by electrical impedance tomography (EIT) during BLVR with EBV. METHODS: Six piglets were submitted to left lower lobe occlusion by a balloon-catheter and EBV valves with FIO2 0.5 and 1.0. Regional end-expiratory lung impedances (EELI) and regional ventilation/perfusion were monitored. Local pocket pressure measurements were obtained (balloon occlusion method). One animal underwent simultaneous acquisitions of computed tomography (CT) and EIT. Regions-of-interest (ROIs) were right and left hemithoraces. RESULTS: Following balloon occlusion, a steep decrease in left ROI-EELI with FIO2 1.0 occurred, 3-fold greater than with 0.5 (p < 0.001). Higher FIO2 also enhanced the final volume reduction (ROI-EELI) achieved by each valve (p < 0.01). CT analysis confirmed the denser atelectasis and greater volume reduction achieved by higher FIO2 (1.0) during balloon occlusion or during valve placement. CT and pocket pressure data agreed well with EIT findings, indicating greater strain redistribution with higher FIO2. CONCLUSIONS: EIT demonstrated in real-time a faster and more complete volume reduction in the occluded lung regions under high FIO2 (1.0), as compared to 0.5. Immediate changes in the ventilation and perfusion of ipsilateral non-target lung regions were also detected, providing better estimates of the full impact of each valve in place. TRIAL REGISTRATION: Not applicable.

Comparison between contact diode laser with 980 nm and 1470 nm wavelengths for posterior laryngofissure in pigs.

To compare two different wavelengths of the surgical contact diode laser (CDL) for producing a posterior laryngofissure in in-vivo pigs. Anesthetized pigs underwent a tracheostomy and an anterior laryngofissure through a cervicotomy. They were randomly selected for the CDL wavelength and Power, according to the peak of Power set at device (980nm wavelength: Ppeak power of 10 W, 15 W, and 20 W, or 1470 nm wavelength: Ppeak 3 W, 5 W, 7 W, 10 W). At the end of the experiment, the laryngotracheal specimen was extracted and sent for histology and morphometry measurements (incision size, depth, area, and lateral thermal damage). Hemodynamic data and arterial blood gases were recorded during the incisions. Statistical analysis of the comparisons between the parameters and groups had a level of significance of p < 0.05. Twenty-six pigs were divided into CDL 980 nm (n = 11) and 1470 nm (n = 15). There was a greater incision area at the thyroid level in the 980 nm CDL and a wider incision at the trachea level, with a larger distance between mucosa borders. There were no significant differences in the area of lateral thermal damage between the two groups and neither difference among the power levels tested. Both wavelengths tested showed similar results in the various combinations of power levels without significant differences in the lateral thermal damage. The posterior laryngofissure incision can be performed by either of the wavelengths at low and medium power levels without great difference on lateral thermal damage.

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.

Brazilian airway surgery survey indicates low overall numbers and need for improved teaching skills.

OBJECTIVES: The Brazilian Society of Thoracic Surgeons conducted an online survey to determine the number of surgeons that perform adult and paediatric airway surgery and to understand the practice patterns along the country. METHODS: Active members were electronically invited to complete the questionnaire through the REDCapR platform. Invitations were sent from January to April 2020. The survey encompassed 40 questions that explored 4 different topics in the assessment of tracheal diseases: (i) surgeon's demography; (ii) institutional profile, (iii) education and training in laryngo-tracheal surgery and (iv) preoperative and postoperative evaluation. RESULTS: Eighty-nine percentage of the responders declared to perform tracheal surgery with a median of 5 tracheal resection procedures per year [interquartile range (IQR) 3-12]. Interaction with other specialties occurs in 37.3% of cases. Access to technology and devices is highly variable across the country. Resident training in airway surgery consists in traditional lectures in 97% of the cases. Training in animals (15.2%), cadavers (12.1%) and simulators (6.1%) are rare. Preoperatory evaluation encompasses flexible bronchoscopy (97.8%) and/or computed tomography (CT) scan of the airways (90.6%). Swallowing (20.1%) and voice (14.4%) disorders are rarely evaluated. Eighty-nine percentage of the surgeons consider bronchoscopy to be the preoperatory gold-standard exam, followed by CT scan (38.8%) and CT-3D reconstruction (37.4%). CONCLUSIONS: Brazilian surgeons refer that airway resection and reconstruction are part of their current practice, but the total number of procedures per surgeon per year is low. Access to high-end technology and equipment is heterogenous. Training offered to residents in most academic institutions relies on traditional lectures.

Implementation and Results of a Dedicated Telemedicine Program (TeleTrachea) for Patients with Tracheal Diseases.

Background: Central airway diseases requiring frequent outpatient visits to a specialized medical center due to tracheal devices. Many of these patients have mobility and cognition restrictions or require specialized transport due to the need for supplemental oxygen. This study describes the implementation and results of a telemedicine program dedicated to patients with central airway diseases based in a Brazilian public health system. Methods: A retrospective study of telemedicine consultation for patients with central airway diseases referred to a public academic hospital between August 1, 2020 and August 1, 2022. The consultations occurred in a telemedicine department using the hospital's proprietary platform. Data retrieved consisted of demographics, disease characteristics, and the treatment modalities of the patients. The analysis included the savings in kilometers not traveled, the carbon footprint based on reducing CO2 emissions, and the cost savings in transportation. Results: A total of 1,153 telemedicine visits conducted in 516 patients (median age of 31.5 years). Two hundred ninety patients (56.2%) had a tracheal device (129 silicone T-Tube, 128 tracheostomy, and 33 endoprosthesis) and 159 patients (30.8%) had difficulties in transportation to the specialized medical center. Patients were served from 147 Brazilian cities from 22 states. The savings in kilometers traveled was 1,224,108.54 km, corresponding to a 250.14 ton reduction in CO2 emissions. The costs savings in transportation for the municipalities was BRL$ 1,272,283.78. Conclusions: Telemedicine consultations for patients with central airway diseases are feasible and safe. Cost savings and the possibility of disseminating specialized care make telemedicine a fundamental tool in current medical practice.

Evaluation of Structural Viability of Porcine Tracheal Scaffolds after 3 and 6 Months of Storage under Three Different Protocols.

Tracheal replacement with a bioengineered tracheal substitute has been developed for long-segment tracheal diseases. The decellularized tracheal scaffold is an alternative for cell seeding. It is not defined if the storage scaffold produces changes in the scaffold's biomechanical properties. We tested three protocols for porcine tracheal scaffold preservation immersed in PBS and alcohol 70%, in the fridge and under cryopreservation. Ninety-six porcine tracheas (12 in natura, 84 decellularized) were divided into three groups (PBS, alcohol, and cryopreservation). Twelve tracheas were analyzed after three and six months. The assessment included residual DNA, cytotoxicity, collagen contents, and mechanical properties. Decellularization increased the maximum load and stress in the longitudinal axis and decreased the maximum load in the transverse axis. The decellularization of the porcine trachea produced structurally viable scaffolds, with a preserved collagen matrix suitable for further bioengineering. Despite the cyclic washings, the scaffolds remained cytotoxic. The comparison of the storage protocols (PBS at 4 °C, alcohol at 4 °C, and slow cooling cryopreservation with cryoprotectants) showed no significant differences in the amount of collagen and in the biomechanical properties of the scaffolds. Storage in PBS solution at 4 °C for six months did not change the scaffold mechanics.

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.

Robotic Lung Volume Reduction Surgery With Extracorporeal Membrane Oxygenation.

Lobectomy for consolidation of failed endoscopic lung volume reduction for emphysema has been reported in selected patients with favorable results but with considerable morbidity. The challenging issues in such patients are frailty caused by severe emphysema itself, poor tolerance to single-lung ventilation, target lobe hyperinflation, and inability to use gas inflation for the minimally invasive resection. Careful planning, including use of a robotic platform and extracorporeal membrane oxygenation support, can circumvent such difficulties and ensure a safe, minimally invasive resection in the high-risk emphysematous patient.

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.

Hybrid Desobstruction of Blind-end Subglottic Stenosis With Long-term Stenting.

Blind-end stenosis (Myer-Cotton IV) is an extreme response to airway injury, resulting in phonatory ablation and dependence on a tracheostomy. A minimally invasive airway desobstruction and stenting can be beneficial in such cases. We present 2 cases of Myer-Cotton IV stenosis that were treated with a minimally invasive desobstruction using a hybrid (endoscopic-surgical) approach followed by the placement of a silicone T-tube.

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.