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.

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.

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.

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.

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.

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.

Radial-probe EBUS for the diagnosis of peripheral pulmonary lesions

Objective:

Conventional bronchoscopy has a low diagnostic yield for peripheral pulmonary lesions. Radial-probe EBUS employs a rotating ultrasound transducer at the end of a probe that is passed through the working channel of the bronchoscope. Radial-probe EBUS facilitates the localization of peripheral pulmonary nodules, thus increasing the diagnostic yield. The objective of this study was to present our initial experience using radial-probe EBUS in the diagnosis of peripheral pulmonary lesions at a tertiary hospital.

Methods:

We conducted a retrospective analysis of 54 patients who underwent radial-probe EBUS-guided bronchoscopy for the investigation of pulmonary nodules or masses between February of 2012 and September of 2013. Radial-probe EBUS was performed with a flexible 20-MHz probe, which was passed through the working channel of the bronchoscope and advanced through the bronchus to the target lesion. For localization of the lesion and for collection procedures (bronchial brushing, transbronchial needle aspiration, and transbronchial biopsy), we used fluoroscopy.

Results:

Radial-probe EBUS identified 39 nodules (mean diameter, 1.9 ± 0.7 cm) and 19 masses (mean diameter, 4.1 ± 0.9 cm). The overall sensitivity of the method was 66.7% (79.5% and 25.0%, respectively, for lesions that were visible and not visible by radial-probe EBUS). Among the lesions that were visible by radial-probe EBUS, the sensitivity was 91.7% for masses and 74.1% for nodules. The complications were pneumothorax (in 3.7%) and bronchial bleeding, which was controlled bronchoscopically (in 9.3%).

Conclusions:

Radial-probe EBUS shows a good safety profile, a low complication rate, and high sensitivity for the diagnosis of peripheral pulmonary lesions.

Objetivo:

A broncoscopia convencional possui baixo rendimento diagnóstico para lesões pulmonares periféricas. A ecobroncoscopia radial (EBUS radial) emprega um transdutor ultrassonográfico rotatório na extremidade de uma sonda que é inserida no canal de trabalho do broncoscópio. O EBUS radial facilita a localização de nódulos pulmonares periféricos, aumentando assim o rendimento diagnóstico. O objetivo deste estudo foi apresentar nossa experiência inicial com o uso de EBUS radial para o diagnóstico de lesões pulmonares periféricas em um hospital terciário.

Métodos:

Foi realizada uma análise retrospectiva de 54 pacientes submetidos à broncoscopia guiada por EBUS radial para a investigação de nódulos ou massas pulmonares entre fevereiro de 2012 e setembro de 2013. O EBUS radial foi realizado com uma sonda flexível de 20 MHz, que foi inserida no canal de trabalho do broncoscópio até chegar à lesão-alvo. A fluoroscopia foi usada para localizar a lesão e realizar procedimentos de coleta (escovado brônquico, aspiração transbrônquica com agulha e biópsia transbrônquica).

Resultados:

O EBUS radial identificou 39 nódulos (média de diâmetro: 1,9 ± 0,7 cm) e 19 massas (média de diâmetro: 4,1 ± 0,9 cm). A sensibilidade global do EBUS radial foi de 66,7% (79,5% para as lesões visíveis pelo método e 25% para as lesões não visíveis pelo método). Nas lesões visíveis pelo método, a sensibilidade foi de 91,7% para massas e de 74,1% para nódulos. As complicações foram pneumotórax (3,7%) e sangramento brônquico controlado broncoscopicamente (9,3%).

Conclusões:

O EBUS radial apresenta bom perfil de segurança, baixo índice de complicações e alta sensibilidade para o diagnóstico de lesões pulmonares periféricas.

Endobronchial ultrasound-guided transbronchial needle aspiration for lung cancer staging: early experience in Brazil

Objective:

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive, safe and accurate method for collecting samples from mediastinal and hilar lymph nodes. This study focused on the initial results obtained with EBUS-TBNA for lung cancer and lymph node staging at three teaching hospitals in Brazil.

Methods:

This was a retrospective analysis of patients diagnosed with lung cancer and submitted to EBUS-TBNA for mediastinal lymph node staging. The EBUS-TBNA procedures, which involved the use of an EBUS scope, an ultrasound processor, and a compatible, disposable 22 G needle, were performed while the patients were under general anesthesia.

Results:

Between January of 2011 and January of 2014, 149 patients underwent EBUS-TBNA for lymph node staging. The mean age was 66 ± 12 years, and 58% were male. A total of 407 lymph nodes were sampled by EBUS-TBNA. The most common types of lung neoplasm were adenocarcinoma (in 67%) and squamous cell carcinoma (in 24%). For lung cancer staging, EBUS-TBNA was found to have a sensitivity of 96%, a specificity of 100%, and a negative predictive value of 85%.

Conclusions:

We found EBUS-TBNA to be a safe and accurate method for lymph node staging in lung cancer patients.

Assessment of the mechanics of a tissue-engineered rat trachea in an image-processing environment

OBJECTIVES

Despite the recent success regarding the transplantation of tissue-engineered airways, the mechanical properties of these grafts are not well understood. Mechanical assessment of a tissue-engineered airway graft before implantation may be used in the future as a predictor of function. The aim of this preliminary work was to develop a noninvasive image-processing environment for the assessment of airway mechanics.

METHOD

Decellularized, recellularized and normal tracheas (groups DECEL, RECEL, and CONTROL, respectively) immersed in Krebs-Henseleit solution were ventilated by a small-animal ventilator connected to a Fleisch pneumotachograph and two pressure transducers (differential and gauge). A camera connected to a stereomicroscope captured images of the pulsation of the trachea before instillation of saline solution and after instillation of Krebs-Henseleit solution, followed by instillation with Krebs-Henseleit with methacholine 0.1 M (protocols A, K and KMCh, respectively). The data were post-processed with computer software and statistical comparisons between groups and protocols were performed.

RESULTS

There were statistically significant variations in the image measurements of the medial region of the trachea between the groups (two-way analysis of variance [ANOVA], p<0.01) and of the proximal region between the groups and protocols (two-way ANOVA, p<0.01).

CONCLUSIONS

The technique developed in this study is an innovative method for performing a mechanical assessment of engineered tracheal grafts that will enable evaluation of the viscoelastic properties of neo-tracheas prior to transplantation.

Effects of acute and chronic administration of methylprednisolone on oxidative stress in rat lungs

OBJECTIVE

To determine the effects of acute and chronic administration of methylprednisolone on oxidative stress, as quantified by measuring lipid peroxidation (LPO) and total reactive antioxidant potential (TRAP), in rat lungs.

METHODS

Forty Wistar rats were divided into four groups: acute treatment, comprising rats receiving a single injection of methylprednisolone (50 mg/kg i.p.); acute control, comprising rats i.p. injected with saline; chronic treatment, comprising rats receiving methylprednisolone in drinking water (6 mg/kg per day for 30 days); and chronic control, comprising rats receiving normal drinking water.

RESULTS

The levels of TRAP were significantly higher in the acute treatment group rats than in the acute control rats, suggesting an improvement in the pulmonary defenses of the former. The levels of lung LPO were significantly higher in the chronic treatment group rats than in the chronic control rats, indicating oxidative damage in the lung tissue of the former.

CONCLUSIONS

Our results suggest that the acute use of corticosteroids is beneficial to lung tissue, whereas their chronic use is not. The chronic use of methylprednisolone appears to increase lung LPO levels.

Effects of methylprednisolone on inflammatory activity and oxidative stress in the lungs of brain-dead rats

OBJECTIVE:

To evaluate the effects that early and late systemic administration of methylprednisolone have on lungs in a rat model of brain death.

METHODS:

Twenty-four male Wistar rats were anesthetized and randomly divided into four groups (n = 6 per group): sham-operated (sham); brain death only (BD); brain death plus methylprednisolone (30 mg/kg i.v.) after 5 min (MP5); and brain death plus methylprednisolone (30 mg/kg i.v.) after 60 min (MP60). In the BD, MP5, and MP60 group rats, we induced brain death by inflating a balloon catheter in the extradural space. All of the animals were observed and ventilated for 120 min. We determined hemodynamic and arterial blood gas variables; wet/dry weight ratio; histological score; levels of thiobarbituric acid reactive substances (TBARS); superoxide dismutase (SOD) activity; and catalase activity. In BAL fluid, we determined differential white cell counts, total protein, and lactate dehydrogenase levels. Myeloperoxidase activity, lipid peroxidation, and TNF-α levels were assessed in lung tissue.

RESULTS:

No significant differences were found among the groups in terms of hemodynamics, arterial blood gases, wet/dry weight ratio, BAL fluid analysis, or histological score-nor in terms of SOD, myeloperoxidase, and catalase activity. The levels of TBARS were significantly higher in the MP5 and MP60 groups than in the sham and BD groups (p < 0.001). The levels of TNF-α were significantly lower in the MP5 and MP60 groups than in the BD group (p < 0.001).

CONCLUSIONS:

In this model of brain death, the early and late administration of methylprednisolone had similar effects on inflammatory activity and lipid peroxidation in lung tissue.

Current status and clinical applicability of endobronchial ultrasound-guided transbronchial needle aspiration

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has played a key role in the diagnosis of mediastinal, paratracheal, and peribronchial lesions, as well as in lymph node staging for lung cancer. Despite its minimally invasive character, EBUS-TBNA has demonstrated a diagnostic yield comparable with that of established surgical methods. It has therefore gained credibility and has become a routine procedure at various referral centers. A successful EBUS-TBNA procedure requires careful planning, which includes a thorough review of the radiological imaging and special care during specimen collection and preparation, as well as technical expertise, experience with the procedure itself, and knowledge of the potential complications inherent to the procedure. The most common indications for EBUS-TBNA include lymph node staging for lung cancer and the diagnostic investigation of mediastinal/hilar masses and lymph node enlargement. Recently, tumor biomarkers in malignant samples collected during the EBUS-TBNA procedure have begun to be identified, and this molecular analysis has proven to be absolutely feasible. The EBUS-TBNA procedure has yet to be included on the Brazilian Medical Association list of medical procedures approved for reimbursement. The EBUS-TBNA procedure has shown to be a safe and accurate tool for lung cancer staging/restaging, as well as for the diagnosis of mediastinal, paratracheal, and peribronchial lesions/lymph node enlargement

Effect of positive end-expiratory pressure after porcine unilateral left lung transplant

OBJECTIVES

To evaluate the effects of 2 different levels of positive end-expiratory pressure on pigs who had unilateral lung transplants.

MATERIALS AND METHODS

A left lung transplant was performed in 12 pigs. The animals were randomized into 2 groups based on positive end-expiratory pressure: group 1 (5 cm H(2)O) and group 2 (10 cm H(2)O). Hemodynamics, gas exchange, and respiratory mechanics were measured before and after surgery. Cytokines, oxidative stress, and histologic scores were assessed in the lung tissue of each pig.

RESULTS

Pigs in group 2 exhibited a significantly higher mean heart rate (P = .006), static compliance (P = .001), lower mean arterial pressure (P = .003), and airway resistance (P = .001) than did pigs in group 1. There were no postoperative differences between the groups in concentrations of thiobarbituric acid reactive substances, superoxide dismutase, and interleukin 8. At the end of the observation period, pigs in group 2 had higher levels of thiobarbituric acid reactive substances (P = .001) and interleukin 8 (P = .05), and pigs in group 1 had higher levels of superoxide dismutase (P = .05) than they did at baseline.

CONCLUSIONS

After unilateral lung transplant, higher positive end-expiratory pressure was associated with improved respiratory mechanics, a negative effect on hemodynamics, a stronger inflammatory response, and increased production of reactive oxygen species, but no effect on gas exchange.

An experimental rat model of ex vivo lung perfusion for the assessment of lungs regarding histopathological findings and apoptosis: low-potassium dextran vs. histidine-tryptophan-ketoglutarate

OBJECTIVE

To compare histopathological findings and the degree of apoptosis among rat lungs preserved with low-potassium dextran (LPD) solution, histidine-tryptophan-ketoglutarate (HTK) solution, or normal saline (NS) at two ischemia periods (6 h and 12 h) using an experimental rat model of ex vivo lung perfusion.

METHODS

Sixty Wistar rats were anesthetized, randomized, and submitted to antegrade perfusion via pulmonary artery with one of the preservation solutions. Following en bloc extraction, the heart-lung blocks were preserved for 6 h or 12 h at 4 ºC and then reperfused with homologous blood for 60 min in an ex vivo lung perfusion system. At the end of the reperfusion, fragments of the middle lobe were extracted and processed for histopathological examination. The parameters evaluated were congestion, alveolar edema, alveolar hemorrhage, inflammatory infiltrate, and interstitial infiltrate. The degree of apoptosis was assessed using the TdT-mediated dUTP nick end labeling method.

RESULTS

The histopathological examination showed that all of the lungs preserved with NS presented alveolar edema after 12 h of ischemia. There were no statistically significant differences among the groups in terms of the degree of apoptosis.

CONCLUSIONS

In this study, the histopathological and apoptosis findings were similar with the use of either LPD or HTK solutions, whereas the occurrence of edema was significantly more common with the use of NS.

Comparison of Celsior and Perfadex lung preservation solutions in rat lungs subjected to 6 and 12 hours of ischemia using an ex-vivo lung perfusion system

OBJECTIVE

This study evaluated the performance of lungs that were preserved with different solutions (Celsior, Perfadex or saline) in an ex vivo rat lung perfusion system.

METHODS

Sixty Wistar rats were anesthetized, anticoagulated and randomized into three groups (n = 20). The rats were subjected to antegrade perfusion via the pulmonary artery with Perfadex, Celsior, or saline, followed by 6 or 12 hours of ischemia (4ºC, n = 10 in each group). Respiratory mechanics, gas exchange and hemodynamics were measured at 10-minute intervals during the reperfusion of heart-lung blocks in an ex vivo system (IL2-Isolated Perfused Rat or Guinea Pig Lung System, Harvard Apparatus, Holliston, Massachusetts, USA; Hugo Sachs Elektronik, Germany) for 60 minutes. The lungs were prepared for histopathology and evaluated for edema following reperfusion. Group comparisons were performed using ANOVA and the Kruskal-Wallis test with a 5% level of significance.

RESULTS

Gas exchange was not significantly different between lungs perfused with either Perfadex or Celsior at the same ischemic times, but it was very low in lungs that were preserved with saline. Airway resistance was greater in the lungs that were preserved for 12 hours. Celsior lungs that were preserved for 6 and 12 hours exhibited lower airway resistance (p = 0.01) compared to Perfadex lungs. Pulmonary artery pressure was not different between the groups, and no significant differences in histopathology and apoptosis were observed between the groups.

CONCLUSIONS

Lungs that were preserved with Celsior or Perfadex exhibited similar gas exchange and histopathological findings. Airway resistance was slightly lower in the Celsior-preserved lungs compared with the Perfadex-preserved lungs.

An experimental rat model of ex vivo lung perfusion for the assessment of lungs after prostacyclin administration: inhaled versus parenteral routes

OBJECTIVE

To present a model of prostaglandin I2 (PGI2) administration (inhaled vs. parenteral) and to assess the functional performance of the lungs in an ex vivo lung perfusion system.

METHODS

Forty Wistar rats were anesthetized and placed on mechanical ventilation followed by median sterno-laparotomy and anticoagulation. The main pulmonary artery was cannulated. All animals were maintained on mechanical ventilation and were randomized into four groups (10 rats/group): inhaled saline (IS); parenteral saline (PS); inhaled PGI2 (IPGI2); and parenteral PGI2 (PPGI2). The dose of PGI2 used in the IPGI2 and PPGI2 groups was 20 and 10 µg/kg, respectively. The heart-lung blocks were submitted to antegrade perfusion with a low potassium and dextran solution via the pulmonary artery, followed by en bloc extraction and storage at 4ºC for 6 h. The heart-lung blocks were then ventilated and perfused in an ex vivo lung perfusion system for 50 min. Respiratory mechanics, hemodynamics, and gas exchange were assessed.

RESULTS

Mean pulmonary artery pressure following nebulization decreased in all groups (p < 0.001), with no significant differences among the groups. During the ex vivo perfusion, respiratory mechanics did not differ among the groups, although relative oxygenation capacity decreased significantly in the IS and PS groups (p = 0.04), whereas mean pulmonary artery pressure increased significantly in the IS group.

CONCLUSIONS

The experimental model of inhaled PGI2 administration during lung extraction is feasible and reliable. During reperfusion, hemodynamics and gas exchange trended toward better performance with the use of PGI2 than that with the use of saline.

Comparing the performance of rat lungs preserved for 6 or 12 hours after perfusion with low-potassium dextran or histidine-tryptophan-ketoglutarate

INTRODUCTION

In lung transplantation, graft dysfunction is a frequent cause of mortality; the etiopathogenesis is related to ischemia-reperfusion injury. We sought to compare the lung performance of rats after reperfusion after presentation with 3 solutions at 2 ischemia times.

METHODS

We randomized 60 male Wistar rats to undergo anterograde perfusion via the pulmonary artery with low-potassium dextran (LPD), histidine-tryptophan ketoglutarate (HTK), or saline. After extraction, the heart-lung blocks were preserved in a solution at hypothermia for 6 or 12 hours before perfusion with homologous blood for 60 minutes using ex vivo system Isolated Perfused Rat or Guinea Pig Lung System (Harvard Apparatus). Respiratory mechanics, pulmonary weight, pulmonary artery pressure (PAP), and relative lung oxygenation capacity (ROC) measurements were obtained every 10 minutes.

RESULTS

Comparing tidal volume (TV), compliance, resistance, ROC, PAP, and pulmonary weight the LPD, HTK, and saline group did not differ at 6 and 12 hours. The TV was higher in the lungs with 6-hour ischemia in the LPD, HTK, and saline groups. Compliance was higher in the lungs with 6-hour ischemia in the LPD and saline groups. There were no differences in ROC values comparing lungs with 6- versus 12-hour ischemia in the LPD group. A significant difference was observed between lungs in the HTK and saline groups. Resistance was higher in the lungs with 12-hour ischemia among the LPD, HTK, and saline groups. There was a gradual weight increase in the lungs, particularly those undergoing 12-hour ischemia, despite the absence of a significant difference between groups.

CONCLUSION

Rat lungs perfused with LPD and HTK preservation solutions showed similar reperfusion performances in this ex-vivo perfusion model.

Bronchoscopic lung-volume reduction with Exhale airway stents for emphysema (EASE trial): randomised, sham-controlled, multicentre trial

BACKGROUND

Airway bypass is a bronchoscopic lung-volume reduction procedure for emphysema whereby transbronchial passages into the lung are created to release trapped air, supported with paclitaxel-coated stents to ease the mechanics of breathing. The aim of the EASE (Exhale airway stents for emphysema) trial was to evaluate safety and efficacy of airway bypass in people with severe homogeneous emphysema.

METHODS

We undertook a randomised, double-blind, sham-controlled study in 38 specialist respiratory centres worldwide. We recruited 315 patients who had severe hyperinflation (ratio of residual volume [RV] to total lung capacity of ≥0·65). By computer using a random number generator, we randomly allocated participants (in a 2:1 ratio) to either airway bypass (n=208) or sham control (107). We divided investigators into team A (masked), who completed pre-procedure and post-procedure assessments, and team B (unmasked), who only did bronchoscopies without further interaction with patients. Participants were followed up for 12 months. The 6-month co-primary efficacy endpoint required 12% or greater improvement in forced vital capacity (FVC) and 1 point or greater decrease in the modified Medical Research Council dyspnoea score from baseline. The composite primary safety endpoint incorporated five severe adverse events. We did Bayesian analysis to show the posterior probability that airway bypass was superior to sham control (success threshold, 0·965). Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00391612.

FINDINGS

All recruited patients were included in the analysis. At 6 months, no difference between treatment arms was noted with respect to the co-primary efficacy endpoint (30 of 208 for airway bypass vs 12 of 107 for sham control; posterior probability 0·749, below the Bayesian success threshold of 0·965). The 6-month composite primary safety endpoint was 14·4% (30 of 208) for airway bypass versus 11·2% (12 of 107) for sham control (judged non-inferior, with a posterior probability of 1·00 [Bayesian success threshold >0·95]).

INTERPRETATION

Although our findings showed safety and transient improvements, no sustainable benefit was recorded with airway bypass in patients with severe homogeneous emphysema.

FUNDING

Broncus Technologies.

Comparison between Perfadex and locally manufactured low-potassium dextran solution for pulmonary preservation in an ex vivo isolated lung perfusion model

INTRODUCTION

Lung transplantation, a consolidated treatment for end-stage lung disease, utilizes preservation solutions, such as low potassium dextran (LPD), to mitigate ischemia-reperfusion injury. We sought the local development of LPD solutions in an attempt to facilitate access and enhance usage. We also sought to evaluate the effectiveness of a locally manufactured LPD solution in a rat model of ex vivo lung perfusion.

METHODS

We randomized the following groups \?\adult of male Wistar rats (n = 25 each): Perfadex (LPD; Vitrolife, Sweden); locally manufactured LPD-glucose (LPDnac) (Farmoterapica, Brazil), and normal saline solution (SAL) with 3 ischemic times (6, 12, and 24 hours). The harvested heart-lung blocks were flushed with solution at 4°C. After storage, the blocks were connected to an IL-2 Isolated Perfused Rat or Guinea Pig Lung System (Harvard Apparatus) and reperfused with homologous blood for 60 minutes. Respiratory mechanics, pulmonary artery pressure, perfusate blood gas analysis, and lung weight were measured at 10-minute intervals. Comparisons between groups and among ischemic times were performed using analysis of variance with a 5% level of significance.

RESULTS

Lungs preserved for 24 hours were nonviable and therefore excluded from the analysis. Those preserved for 6 hours showed better ventilatory mechanics when compared with 12 hours. The oxygenation capacity was not different between lungs flushed with LPD or LPDnac, regardless of the ischemic time. SAL lungs showed higher PCO(2) values than the other solutions. Lung weight increased over time during perfusion; however, there were no significant differences among the tested solutions (LPD, P = .23; LPDnac, P = .41; SAL, P = .26). We concluded that the LPDnac solution results in gas exchange were comparable to the original LPD (Perfadex); however ventilatory mechanics and edema formation were better with LPD, particularly among lungs undergoing 6 hours of cold ischemia.

Bronchial thermoplasty in asthma

Currently available treatments for asthma provide satisfactory control of the disease in most cases. However, a significant number of patients do not respond to such treatments (i.e., do not achieve effective symptom relief). One novel approach to treating asthma is bronchial thermoplasty, in which the airway smooth muscle is specifically and directly treated. This procedure delivers radiofrequency energy to the airways in order to reduce smooth muscle-mediated bronchoconstriction. In this article, we present the thermoplasty technique, summarizing the results of the major randomized clinical trials of the procedure, as well as discussing its mechanisms of action and potential adverse effects. We also propose strategies for the future clinical use of this new treatment.

Suspension laryngoscopy for the thoracic surgeon: when and how to use it

Suspension laryngoscopy is one of the most common otolaryngological procedures for the diagnosis and surgical approach to the larynx. However, most thoracic surgeons are not familiar with the procedure and seldom use it. The indications for its use are similar to those for that of rigid bronchoscopy (dilatation, endoprosthesis insertion, and tumor resection). It can be performed in children and adults. Suspension laryngoscopy is an alternative when rigid bronchoscopy is unavailable and is therefore a viable option for use at smaller facilities. In this communication, we describe the technique and the applications of suspension laryngoscopy in thoracic surgery.

Ventilation strategy and its influence on the functional performance of lung grafts in an experimental model of single lung transplantation using non-heart-beating donors

OBJECTIVE

To compare the influence of two different ventilation strategies-volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV)-on the functional performance of lung grafts in a canine model of unilateral left lung transplantation using donor lungs harvested after three hours of normothermic cardiocirculatory arrest under mechanical ventilation.

METHODS

The study comprised 40 mongrel dogs, randomized into two groups: VCV and PCV. Of the 20 recipients, 5 did not survive the transplant, and 5 died before the end of the post-transplant assessment period. The remaining 10 survivors (5 in each group) were evaluated for 360 min after lung transplantation. The functional performance of the grafts was evaluated regarding respiratory mechanics, gas exchange, and lung graft histology.

RESULTS

There were no significant differences between the groups regarding respiratory mechanics (peak inspiratory pressure, plateau pressure, mean airway pressure, dynamic compliance, and static compliance) or gas exchange variables (PaO2, venous oxygen tension, PaCO2, venous carbon dioxide tension, and the arterial-venous oxygen content difference). The histopathological findings were consistent with nonspecific acute lung injury and did not differ between the groups.

CONCLUSIONS

This model of lung transplantation showed that the functional performance of lung grafts was not influenced by the ventilation strategy employed during the first six hours after reperfusion.

Modelo experimental de perfusão pulmonar isolada em ratos: técnica e aplicações em estudos de preservação pulmonar

Estudos de preservação pulmonar em modelos experimentais realizados em animais de pequeno porte são de realização mais simples e barata. Esta comunicação tem o enfoque de descrever tecnicamente um modelo de perfusão pulmonar ex vivo em ratos, com o uso de um equipamento disponível comercialmente que foi o primeiro a ser instalado em um laboratório de pesquisa em cirurgia torácica no Brasil. Descrevemos detalhadamente o modelo e sua preparação, assim como suas aplicações para estudos de preservação pulmonar. Os detalhes técnicos da preparação podem ser observados também em um vídeo postado no site do Jornal Brasileiro de Pneumologia.

Prevalence of gastroesophageal reflux disease in patients with idiopathic pulmonary fibrosis

OBJECTIVE

To determine the prevalence of gastroesophageal reflux disease (GERD) and to evaluate its clinical presentation, as well as the esophageal function profile in patients with idiopathic pulmonary fibrosis (IPF).

METHODS

In this prospective study, 28 consecutive patients with IPF underwent stationary esophageal manometry, 24-h esophageal pH-metry and pulmonary function tests. All patients also completed a symptom and quality of life in GERD questionnaire.

RESULTS

In the study sample, the prevalence of GERD was 35.7%. The patients were then divided into two groups: GERD+ (abnormal pH-metry; n = 10) and GERD- (normal pH-metry; n = 18). In the GERD+ group, 77.7% of the patients presented at least one typical GERD symptom. The pH-metry results showed that 8 (80%) of the GERD+ group patients had abnormal supine reflux, and that the reflux was exclusively in the supine position in 5 (50%). In the GERD+ and GERD- groups, respectively, 5 (50.0%) and 7 (38.8%) of the patients presented a hypotensive lower esophageal sphincter, 7 (70.0%) and 10 (55.5%), respectively, presenting lower esophageal dysmotility. There were no significant differences between the groups regarding demographic characteristics, pulmonary function, clinical presentation or manometric findings.

CONCLUSIONS

The prevalence of GERD in the patients with IPF was high. However, the clinical and functional characteristics did not differ between the patients with GERD and those without.

Surgical treatment of bronchial carcinoid tumors: a single-center experience

BACKGROUND

Bronchial carcinoid is an infrequent neoplasm with a neuroendocrine differentiation. Surgical treatment is the gold standard therapy, with procedures varying from sublobar resections to complex lung sparing broncoplastic procedures. This study evaluates the results of surgical treatment of bronchial carcinoids and its prognostic factors.

PATIENTS AND METHODS

Retrospective review of 126 consecutive patients who underwent surgical treatment for bronchial carcinoid tumors between December 1974 and July 2007.

RESULTS

There were 70 females (55%) and the mean age was 46 years, ranging from 17 to 81 years. Upon clinical presentation, 38 patients (30%) have had recurrent respiratory tract infection, 31 (24%) cough, 16 (12%) chest pain and 25 (20%) were asymptomatic. Preoperative bronchoscopic diagnosis was obtained in 74 cases (58.7%). The procedures performed were: 19 sublobar resections (14,9%), 58 lobectomies (46%), 8 bilobectomies (6.3%), 6 pneumonectomies (4.7%), 2 sleeve segmentectomies (1.5%), 26 sleeve lobectomies (20.6%) and 9 bronchoplastic procedures without lung resection (7.1%). Operative mortality was 1.5% (n = 2) and morbidity was 25.8% (n=32), including 12 respiratory tract infections and 4 reinterventions due to bleeding (3) and pleural empyema (1). Among the 112 patients available for follow-up, the overall survival at 3, 5 and 10 years was 89.2%, 85.5% and 79.8%, respectively. Five and 10-year survival for typical and atypical carcinoids were 91, 89% and 56, 47%, respectively. Overall disease-free survival at 5 years was 91.9% Statistical analysis showed that overall disease-free survival correlated with histology--typical vs. atypical--(p = 0.04) and stage (p = 0.02).

CONCLUSION

Surgery provides safe and adequate treatment to bronchial carcinoid tumors. Histology and stage were the main prognostic factors.

Prevalence of gastroesophageal reflux in lung transplant candidates with advanced lung disease

OBJECTIVE

To assess the esophageal function profile and the prevalence of gastro-esophageal reflux (GER) in lung transplant candidates.

METHODS

From July of 2005 to November of 2006, a prospective study was conducted involving 55 candidates for lung transplantation at the Santa Casa de Misericórdia Hospital in Porto Alegre, Brazil. Prior to transplantation, patients underwent outpatient stationary esophageal manometry and 24-h esophageal pH-metry using one and two electrodes.

RESULTS

Abnormal esophageal manometry was documented in 80% of the patients, and 24% of the patients presented pathological acid reflux. Digestive symptoms presented sensitivity and specificity for GER of 50% and 61%, respectively. Of the patients with chronic obstructive pulmonary disease, 94% presented abnormal esophageal manometry, and 80% presented lower esophageal sphincter hypotonia, making it the most common finding. Patients with bronchiectasis presented the highest prevalence of GER (50%).

CONCLUSIONS

In patients with advanced lung disease, GER is highly prevalent. In the population studied, digestive symptoms of GER were not predictive of pathological acid reflux. The role that GER plays in chronic rejection should be examined and clarified in future studies.

Esophageal manometry and 24-h esophageal pH-metry in a large sample of patients with respiratory symptoms

OBJECTIVE

To determine the prevalence of gastroesophageal reflux disease (GERD) and to evaluate the esophageal motor profile of patients with respiratory symptoms referred to a digestive motility referral center for esophageal function testing.

METHODS

The results of esophageal manometry and 24-h esophageal pH-metry were analyzed.The inclusion criterion was presenting respiratory symptoms, with or without accompanying digestive symptoms.

RESULTS

Of the 1,170 patients included in the study, 602 (51.5%) reported having digestive and respiratory symptoms (DRS group), and 568 (48.5%) reported having only respiratory symptoms (RS group). Asthma was diagnosed in 142 patients in the RS group (RS-A subgroup) and in 201 of those in the DRS group (DRS-A). Of the 346 cases of esophageal dysmotility, hypomotility was found in 175 (14.3% and 15.6% in the DRS and RS groups, respectively), and lower esophageal sphincter (LES) hypotonia was found in 411 (40.3% and 30.2%, respectively). Hypotonia correlated with GERD. Exposure of the distal esophagus to acid was markedly abnormal in the supine position. The prevalence of GERD in the sample as a whole, the RS-A/DRS-A subgroups and the RS-A subgroup alone was 39.8%, 44.0% and 35.2%, respectively

CONCLUSIONS

Hypotonic LES was the most common abnormality and correlated with GERD. Although GERD was more evident in the DRS group, approximately one third of the patients in the RS group also presented GERD (silent GERD). The findings suggest that GERD can be an extrapulmonary cause of chronic respiratory symptoms unresponsive to conventional therapy.

Ischemic preconditioning by selective occlusion of the pulmonary artery in rats

OBJECTIVE

To evaluate the effect of lung ischemic preconditioning (IPC) on normothermic ischemia/reperfusion (I/R) injury in a rat model, quantifying the production of reactive oxygen species.

METHODS

Forty-seven male Wistar rats were randomized into four groups: control, sham, I/R and IPC. Control group animals were anesthetized and killed by decapitation, after which pneumonectomy was performed and the left lungs were stored in liquid nitrogen. Sham, IPC and I/R group rats were anesthetized, tracheostomized, ventilated, anticoagulated and submitted to left thoracotomy with dissection of the left pulmonary artery for clamping. Sham group rats underwent dissection of the left pulmonary artery, I/R group rats underwent 30 min of total hilar clamping, and IPC group rats underwent 5-min clamping of the left pulmonary artery followed by 30 min of total hilar clamping. Lungs were reperfused for 90 min and ventilated with the same parameters, with additional positive end-expiratory pressure of 1 cmH2O. Hemodynamic and blood gas values were obtained prior to thoracotomy, prior to total hilar clamping, after 30 min of reperfusion and after 90 min of reperfusion. Lipid peroxidation was determined by measuring levels of thiobarbituric acid reactive substances.

RESULTS

There were no significant differences among the groups in terms of the levels of thiobarbituric acid reactive substances. Nor were there any significant differences among the sham, I/R and IPC groups in terms of arterial oxygen tension, arterial carbon dioxide tension or hemodynamic values.

CONCLUSIONS

In an in situ I/R rat model, 5-min IPC of the left pulmonary artery does not attenuate I/R injury.

[Bronchial thermoplasty: report on the first endoscopic treatment for asthma in Latin America]

Bronchial thermoplasty is a new bronchoscopic procedure that delivers radiofrequency energy to the airway and potentially reduces the smooth muscle-mediated bronchoconstriction. We report the case of a 48-year-old man with persistent moderate asthma submitted to bronchial thermoplasty. The treatment increased the forced expiratory volume in one second, increased the number of symptom-free days, reduced the use of relief medications, and improved the Juniper Asthma Quality of Life Scale score. In this patient, bronchial thermoplasty was well tolerated and safe. This was the first bronchial thermoplasty performed in Latin America. At 12 months after the procedure, the results were encouraging in terms of its potential benefits in patients with difficult-to-control asthma.

The effects of positive end-expiratory pressure in alveolar recruitment during mechanical ventilation in pigs

PURPOSE

To evaluate the effects of alveolar recruitment based on mean airway pressure (MAP) on pig lungs submitted to thoracotomy through blood gas exchange and hemodynamic parameters.

METHODS

Twelve pigs weighting approximately 25 Kg were intubated and ventilated on volume controlled ventilation (tidal volume 10 ml/Kg, respiratory rate 16 min, FiO2 1.0, inspiratory:expiratory ratio 1:2, PEEP 5 cmH2O). The animals were then randomized into two groups: control and left lateral thoracotomy. The PEEP was increased at each 15-minute intervals to reach a MAP of 15, 20 and 25 cmH2O, respectively. Hemodynamic, gas exchange and respiratory mechanic data were measured immediately before each PEEP change.

RESULTS

There were no significant differences between both groups in all parameters analyzed (P=1.0). The PaO2, PaCO2, MAP, PAP and plateau pressure were significantly worse at MAP of 25 cmH2O, when compared with the other values of MAP (P=0.001, P=0.039, P=0.001, P=0.016 e P=0.027, respectively). The best pulmonary performance according to the analyzed parameters was observed at MAP of 20 cmH2O.

CONCLUSION

PEEP adjusted to MAP of 20 cmH2O resulted in best arterial oxygenation, without compromising the venous return, as opposed to MAP of 25 cmH2O, which caused deterioration of gas exchange, hemodynamics and respiratory mechanic.

Technical modification of unilateral lung transplantation in rats

The increasing demand in transplantation research requires efficient and less expensive animal models in order to obtain reliable results that are reproducible in larger animal models and, ultimately, applied clinically. The model of unilateral left lung transplantation in rats has proven to be a useful alternative for those purposes. We demonstrate a technical modification of this model, which consists of the isolation and ligation of the contralateral (right) pulmonary artery, allowing blood circulation exclusively in the transplanted lung. This model is feasible and reproducible. However, the short survival time restricts the assessment of the transplanted lung to a maximum period of three hours.

Evaluation of pantoprazol treatment response of patients with asthma and gastroesophageal reflux: a randomized prospective double-blind placebo-controlled study

OBJECTIVES

To determine the effect that the treatment of GERD has on the clinical management, as well as the respiratory function, of patients with asthma and to evaluate the clinical characteristics of this group of patients.

METHODS

Patients with asthma and concomitant GERD, documented using 24 h pH-metry, were evaluated by means of quality of life questionnaires, as well as questionnaires related to respiratory and digestive symptoms. In addition, esophageal manometry, spirometry and the determination of peak expiratory flow were also performed prior to and after the study. Forty-nine individuals who were diagnosed with GERD by means of 24 h esophageal pH-metry were selected and participated in a clinical randomized double-blind placebo-controlled study, involving the administration of 40 mg/day of pantoprazol for 12 consecutive weeks.

RESULTS

Forty-four individuals completed the study (n = 22 per group). There was significant improvement in the scores for respiratory symptoms and quality of life only in the group that received pantoprazol (p = 0.01 and p = 0.001, respectively). No respiratory function parameters changed in either group.

CONCLUSIONS

In this study, the effective treatment of GERD improved patient quality of life, and the symptoms of asthma significantly decreased in the group that received the medication. There were no changes in pulmonary function parameters.

Lobectomia por carcinoma brônquico: análise das co-morbidades e seu impacto na morbimortalidade pós-operatória

OBJETIVO: Analisar o impacto das co-morbidades no desempenho pós-operatório de lobectomia por carcinoma brônquico. MÉTODOS: Estudaram-se retrospectivamente 493 pacientes submetidos a lobectomia por carcinoma brônquico e 305 preencheram os critérios de inclusão. A técnica cirúrgica foi sempre semelhante. Analisaram-se as co-morbidades categorizando-se os pacientes nas escalas de Torrington-Henderson e de Charlson, estabelecendo-se grupos de risco para complicações e óbito. RESULTADOS: A mortalidade operatória foi de 2,9% e o índice de complicações de 44%. O escape aéreo prolongado foi a complicação mais freqüente (20,6%). A análise univariada mostrou que sexo, idade, tabagismo, terapia neo-adjuvante e diabetes apresentaram impacto significativo na incidência de complicações. O índice de massa corporal (23,8 ± 4,4 kg/m²), volume expiratório forçado no primeiro segundo (74,1 ± 24%) e relação entre volume expiratório forçado no primeiro segundo e capacidade vital forçada (0,65 ± 0,1) foram fatores preditivos da ocorrência de complicações. As escalas foram eficazes na identificação de grupos de risco e na relação com a morbimortalidade (p = 0,001 e p < 0,001). A análise multivariada identificou que o índice de massa corporal e o índice de Charlson foram os principais determinantes de complicações; o escape aéreo prolongado foi o principal fator envolvido na mortalidade (p = 0,01). CONCLUSÃO: Valores reduzidos de volume expiratório forçado no primeiro segundo, relação entre volume expiratório forçado no primeiro segundo e capacidade vital forçada, índice de massa corporal e graus 3-4 de Charlson e 3 de PORT associaram-se a mais complicações após lobectomias por carcinoma brônquico. O escape aéreo persistente associou-se fortemente à mortalidade.

Partial liquid ventilation with perfluorodecalin following unilateral canine lung allotransplantation in non–heart-heating donors

BACKGROUND

The purpose of this study was to evaluate canine lungs obtained from non-heart-beating donors after unilateral lung transplantation subjected to partial liquid ventilation with perfluorodecalin.

METHODS

Twelve donor dogs were killed and kept under mechanical ventilation for 3 hours. Heart-lung blocks were harvested after retrograde pulmonary hypothermic flush with Perfadex. Left lung grafts were randomly transplanted into 12 weight-matched recipient animals. Animals were divided into 2 groups: control (standard mechanical ventilation, n = 6) and PLV (partial liquid ventilation, n = 6). Forty-five minutes after transplantation, the animals in the PLV group received perfluorodecalin (15 ml/kg) via orotracheal tube. All animals received volume-controlled ventilation (FIO2) 1.0, PEEP 5 cm H(2)O) over 6 consecutive hours. Thereafter, blood-gas analysis, ventilatory mechanics and hemodynamics were registered at 30-minute intervals. After 6 hours of reperfusion the animals were killed and the transplanted lungs were extracted to obtain the wet/dry weight ratio.

RESULTS

There were significant differences in pulmonary arterial pressure, which were higher in control group animals (p < 0.009). The control animals also showed higher arterial PaO(2) than those in the PLV group (p < 0.00001), but lower PaCO(2) (p < 0.008). The peak and plateau pressures were higher in the PLV group (p < 0.00001). Neither static compliance nor wet/dry weight ratios were different in between groups.

CONCLUSIONS

PLV with perfluorodecalin yields functional results compatible with life in this model. Nonetheless, pulmonary gas exchange and mechanics were superior after reperfusion in animals given conventional mechanical ventilation up to 6 hours after left lung allotransplantation.

Bronquiectasias: aspectos diagnósticos e terapêuticos Estudo de 170 pacientes

INTRODUÇÃO: Bronquiectasias são freqüentemente encontradas na prática médica no Brasil, levando a significativa morbidez e comprometimento da qualidade de vida de seus portadores. OBJETIVOS: Analisar aspectos diagnósticos e terapêuticos em uma série de pacientes com bronquiectasias atendidos em um serviço de doenças pulmonares. MÉTODO: Sinais, sintomas, achados radiográficos e microbiológicos, e resultados terapêuticos foram estudados em 170 pacientes portadores de bronquiectasias hospitalizados no período de 1978 a 2001 - 62,4% do sexo feminino, 37,6% do masculino, com idade média de 37 anos, variando entre 12 e 88 anos. RESULTADOS: Antecedente de pneumonia na infância foi detectado em 52,5% dos pacientes, de tratamento tisiológico em 19,8%; 8,8% tinham asma brônquica, e dois tinham síndrome de Kartagener. Os sintomas mais comuns foram tosse (100%), expectoração (96%) e estertores pulmonares (66%). As lesões eram unilaterais em 46,5% dos casos. Pneumococo, H. influenzae ou flora mista estiveram presentes em 85% das amostras de escarro examinadas. Os 170 pacientes receberam inicialmente tratamento clínico à base de antibióticos e fisioterapia respiratória; 88 deles (52%) mais jovens, com lesões menores e boa reserva funcional foram submetidos à cirurgia de ressecção pulmonar (82 unilaterais e seis bilaterais). Ocorreram dois óbitos hospitalares entre os pacientes que receberam tratamento exclusivamente clínico. Os pacientes tratados cirurgicamente tiveram acentuada melhora dos sintomas, raramente necessitando ser reinternados. CONCLUSÕES: Os prolongados sintomas broncopulmonares foram permanentemente aliviados na maioria dos pacientes com bronquiectasias que puderam ir à cirurgia de ressecção pulmonar, diferentemente dos que seguiram com o tratamento clínico.

Intrathoracic desmoid tumor with invasion of the great vessels

A desmoid tumor of the mediastinum was diagnosed and treated in a 35-year-old white male who presented with a right supraclavicular mass. He was treated with resection, which involved several vascular structures, requiring multiple vascular reconstructions followed by post-operative radiotherapy. The authors concluded that, when located in the mediastinum, the invasive character of such tumors and its tendency to recur may pose a considerable surgical challenge, requiring careful pre-operative planning and long term post-operative follow -up. The role of radiation therapy is limited to the control of local recurrences.