Objective: To evaluate the use of ex vivo lung perfusion (EVLP) clinically to prepare donor lungs for transplantation. Methods: A prospective study involving EVLP for the reconditioning of extended-criteria donor lungs, the criteria for which include aspects such as a PaO2/FiO2 ratio < 300 mmHg. Between February of 2013 and February of 2014, the lungs of five donors were submitted to EVLP for up to 4 h each. During EVLP, respiratory mechanics were continuously evaluated. Once every hour during the procedure, samples of the perfusate were collected and the function of the lungs was evaluated. Results: The mean PaO2 of the recovered lungs was 262.9 ± 119.7 mmHg at baseline, compared with 357.0 ± 108.5 mmHg after 3 h of EVLP. The mean oxygenation capacity of the lungs improved slightly over the first 3 h of EVLP-246.1 ± 35.1, 257.9 ± 48.9, and 288.8 ± 120.5 mmHg after 1, 2, and 3 h, respectively-without significant differences among the time points (p = 0.508). The mean static compliance was 63.0 ± 18.7 mmHg, 75.6 ± 25.4 mmHg, and 70.4 ± 28.0 mmHg after 1, 2, and 3 h, respectively, with a significant improvement from hour 1 to hour 2 (p = 0.029) but not from hour 2 to hour 3 (p = 0.059). Pulmonary vascular resistance remained stable during EVLP, with no differences among time points (p = 0.284). Conclusions: Although the lungs evaluated remained under physiological conditions, the EVLP protocol did not effectively improve lung function, thus precluding transplantation.

Keywords: Lung transplantation; Organ preservation; Brain death; Donor selection.

In the last 20 years, lung transplantation has become the standard treatment for patients with end-stage lung disease. However, less than 20% of the donor lungs available for transplant are actually usable. This disparity between the growing number of recipients and the small number of donors has resulted in increased mortality among lung transplant candidates on waiting lists. Strategies such as the utilization of organs from marginal donors have proven ineffective in increasing the number of transplants. In 2000, a new method for reconditioning human lungs that had been previously rejected for transplantation was developed in Sweden. We describe our initial experience with ex vivo lung perfusion.

Keywords: Lung transplantation; Organ preservation; Organ preservation solutions; Thoracic surgery.

Lung transplantation has come to be viewed as the best treatment option for various end-stage lung diseases. The low number of viable donors continues to be a major obstacle to increasing the number of lung transplants, resulting in high mortality among patients on the waiting list. Unlike transplantation of other solid organs, lung transplantation is primarily limited not by the absolute number of donors but by the viability of the donor lungs, which can be damaged by brain death and by treatments given in the ICU. There are various proposals of ways to increase the number of lung donors: intensification of donation campaigns, use of non-heart-beating donors, living lobar lung transplantation, and adoption of more flexible criteria for donors. However, the proposal that has attracted the most attention from lung transplant groups is ex vivo lung perfusion, especially due to the prospect of reconditioning previously discarded lungs. This system consists of perfusion and ventilation of the isolated heart-lung block using a modified cardiopulmonary bypass circuit. Various authors have been studying this technique due to the satisfactory results obtained and the prospect of an increase in the number of organs suitable for transplantation. Researchers in Sweden, Canada, Austria, England, Spain, and Brazil have extensive experience with the method and have introduced modifications to it. The objective of this article was to review the development of, state of the art in, and future prospects for the ex vivo model of lung perfusion and reconditioning.

Keywords: Lung transplantation; Transplantation conditioning; Perfusion; Organ preservation.

Small animal models are particularly suitable for lung preservation studies, because they are simple and cost-effective. This brief communication focuses on the technical description of an ex vivo lung perfusion model in rats by means of a commercially available apparatus, which was the first to be installed in a thoracic surgery research laboratory in Brazil. The model and its preparation, together with its applications for lung preservation studies, are described in detail. All technical details can also be seen in a video posted on the website of the Brazilian Journal of Pulmonology.

Keywords: Lung transplantation; Reperfusion injury; Rats; Models, animal.

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 4°C 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.

Keywords: Prostaglandins; Lung transplantation; Reperfusion; Models, animal; Rats.

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°C 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.

Keywords: : Organ preservation; Organ preservation solutions; Lung transplantation; Reperfusion injury; Apoptosis.

Since they were first established, ex vivo models of lung reconditioning have been evaluated extensively. When rejected donor lungs are used, the great variability among the cases can hinder the progress of such studies. In order to avoid this problem, we developed a technique that consists of separating the lung block into right and left blocks and subsequently reconnecting those two blocks. This technique allows us to have one study lung and one control lung.

Keywords: Lung transplantation; Transplantation conditioning; Organ preservation; Organ preservation solutions.

The ischemia-reperfusion injury is a common pathophysiologic phenomenon in many diseases seen in daily clinical practice. The lung can be affected both directly, as in pulmonary edema after lung transplant or after resolution of pulmonary thromboembolism, and indirectly, as in shock states or after reperfusion injury in distant organs as intestine or lower extremities. The latter situation can occur secondary to aortic occlusion for surgical procedures. Many mediators have been implicated in the ischemia-reperfusion injury: oxygen free radicals, lipid products as thromboxane, adhesion molecules involved in leukocyte-endothelial interaction, tumor necrosis factor, among others. Therapeutic strategies for the reperfusion injury are used only at the experimental level and in very few clinical studies. Antioxidants, inhibitors of lipid mediators and of the leukocyte-endothelial interaction and promoters of blood flow in post-ischemic vessels have been used.

Keywords: Lung. Injury. Reperfusion. Ischemia.

Lung retrieval following cardio-circulatory arrest has been studied experimentally, however severe ischemia/reperfusion injury requires improved methods of graft preservation. Allograft perfusion with crystalloid solution delivered via pulmonary artery (antegrade perfusion) remains the standard procedure, however it does not provide adequate washout of the blood retained within the bronchial circulation which may trigger reperfusion injury. This has led the authors to test the impact of antegrade versus retrograde (via left atrium) perfusion of lung grafts submitted to 3 hours of warm ischemia after cardio-circulatory arrest in a dog model of left lung allotransplantation. Twelve donor dogs were sacrificed with thiopental sodium and kept under mechanical ventilation at room temperature for 3 hours. They were randomized and the heart-lung blocks harvested after being perfused in a retrograde (group I, n = 6) or antegrade (group II, n = 6) fashion with modified Euro-Collins solution. Twelve recipient animals were submitted to a left lung transplant receiving the grafts from both groups and the assessment was performed during 6 hours. Hemodynamic parameters were similar for animals in both groups. The gas exchange (arterial PaO2 and PaCO2) in recipients of group I (retrograde perfusion) was significantly better when compared to recipients of grafts perfused via pulmonary artery. Intracellular ATP did not show difference between the groups, however there was a measurable drop in its values when samples obtained upon extraction were compared to those measured after reperfusion and at the end of the assessment. The authors concluded that retrograde perfusion yields better pulmonary function after 6 hours of reperfusion in this animal model of left lung allotransplantation following 3 hours of normothermic ischemia under mechanical ventilation.

Keywords: Lung. Ischemia. Preservation. Retrograde perfusion. ATP.

Lung cancer is one of the most incident types of cancer and a leading cause of cancer mortality in Brazil. We reviewed the current status of lung cancer by searching relevant data on prevention, diagnosis, and treatment in the country. This review highlights several issues that need to be addressed, including smoking control, patient lack of awareness, late diagnosis, and disparities in the access to cancer health care facilities in Brazil. We propose strategies to help overcome these limitations and challenge health care providers, as well as the society and governmental representatives, to work together and to take a step forward in fighting lung cancer.

Keywords: Lung neoplasms/epidemiology; Lung neoplasms/therapy; Lung neoplasms/diagnosis; Biomarkers; Brazil.

Objective: To assess the relative frequency of incident cases of interstitial lung diseases (ILDs) in Brazil. Methods: This was a retrospective survey of new cases of ILD in six referral centers between January of 2013 and January of 2020. The diagnosis of ILD followed the criteria suggested by international bodies or was made through multidisciplinary discussion (MDD). The condition was characterized as unclassifiable ILD when there was no specific final diagnosis following MDD or when there was disagreement between clinical, radiological, or histological data. Results: The sample comprised 1,406 patients (mean age = 61 ± 14 years), and 764 (54%) were female. Of the 747 cases exposed to hypersensitivity pneumonitis (HP)-related antigens, 327 (44%) had a final diagnosis of HP. A family history of ILD was reported in 8% of cases. HRCT findings were indicative of fibrosis in 74% of cases, including honeycombing, in 21%. Relevant autoantibodies were detected in 33% of cases. Transbronchial biopsy was performed in 23% of patients, and surgical lung biopsy, in 17%. The final diagnoses were: connective tissue disease-associated ILD (in 27%), HP (in 23%), idiopathic pulmonary fibrosis (in 14%), unclassifiable ILD (in 10%), and sarcoidosis (in 6%). Diagnoses varied significantly among centers (?2 = 312.4; p < 0.001). Conclusions: Our findings show that connective tissue disease-associated ILD is the most common ILD in Brazil, followed by HP. These results highlight the need for close collaboration between pulmonologists and rheumatologists, the importance of detailed questioning of patients in regard with potential exposure to antigens, and the need for public health campaigns to stress the importance of avoiding such exposure.

Keywords: Lung diseases, interstitial/epidemiology; Alveolitis, extrinsic allergic/epidemiology; Connective tissue diseases/epidemiology, Sarcoidosis/epidemiology; Idiopathic pulmonary fibrosis/epidemiology

Bronchial healing remains one of the dominant issues in lung transplantation. Among other factors, the quality of airway protection during procurement may contribute to improve bronchial healing. In most centers lung preservation is performed using the pulmonary artery (PA) flush perfusion (FP). The present study was performed to investigate the influence of different routes of perfusion on the distribution of Euro-Collins solution (EUC) in lung parenchyma and upper airways in swine. The animals were divided into 4 groups, 1 without FP; Control (n=6), and the others with EUC delivery via: pulmonary artery (PA) (n=6); pulmonary and bronchial arteries simultaneously (PA+BA) (n=8), and pulmonary veins (PV). Lungs and airways were assessed by the following methods: dye-labeled microspheres for total and regional perfusion, tissue water content, and lung temperature. There was no significant difference in total lung flow between PA+BA and PA, both superior to the PV group. Flow in the proximal and distal trachea were significantly increased: PA+BA (0.970 ± 0.4 and 0.380 ± 0.2 mL/min/g, respectively); PA ( 0.023 ± 0.007 and 0.024 ± 0.07 mL/min/g, respectively); PV (0.009 ± 0.003 and 0.021 ± 0.006 mL/min/g respectively) and Control experiments (0.125 ± 0.0018 and 0.105 ±0.012 mL/min/g, respectively). The highest flow rates in the right main bronchus were achieved by PA+BA (1.04 ± 0.4 mL/min/g) as comparison to Control, PA, and PV groups (0.11 ± 0.03, 0.033 ± 0.008, and 0.019 ± 0.005 mL/min/g, respectively). Flows in the left main bronchus were significantly increased by PA+BA (0.97 ± 0.3 mL/min/g), as comparison to control, PA and PV groups (0.09 ± 0.02, 0.045 ± 0.012, and 0.027 ± 0.006 mL/min/g, respectively). In conclusion, these data showed that the distribution of EUC in airways of swine is significantly improved by PA+BA perfusion.

Keywords: Lung transplantation. Flush perfusion. Bronchial circulation. Bronchial complications.

Objective: Asthma and respiratory symptoms are common in children, and many studies have shown associations between childhood symptoms and impaired lung function in adult life. The aim of the present study was to investigate the association of various respiratory symptoms with wheezing patterns (persistent, early, and late-onset) and lung function, as well as to determine whether lung function was associated with atopy or with demographic, socioeconomic, environmental, and gestational factors, in a birth cohort at 6-7 years of age. Methods: The target population consisted of children aged 6-7 years from a birth cohort of 5,304 children born in southern Brazil in 1993. For this follow-up evaluation, 532 of those children were randomly selected, and a sub-sample was submitted to spirometry and skin prick tests. A questionnaire was administered to the parent(s) or legal guardian(s) of each child. Results: Spirometric values were lower in the children with respiratory symptoms or asthma. Mean forced expiratory volume in one second/forced vital capacity ratio (FEV1/FVC ratio) was lower in children with any of the following: current wheezing and asthma; asthma ever; four or more episodes of wheezing within the preceding 12 months; sleep disturbance due to wheezing; and exercise-induced wheezing. Persistent wheezing was associated with lower FEV1/FVC ratio. After multiple linear regression, exercise-induced wheezing was also associated with reduced FEV1/FVC ratio. Nonwhite skin color and wheezing severe enough to limit speech were associated with lower FEV1. Conclusions: Children with persistent wheezing and symptoms of severe asthma have impaired lung function at 6-7 years of age.

Keywords: Asthma; Respiratory function tests; Respiratory sounds; Signs and symptoms, respiratory.

Objective: The incidence of lung disease caused by nontuberculous mycobacteria (NTM) has been increasing worldwide. In Brazil, there are few studies about nontuberculous mycobacterial lung disease (NTMLD), and its prevalence is yet to be known. Our objective was to determine the specific etiology of the disease in the state of Rio Grande do Sul, Brazil, as well as the frequency and diversity of NTM species in our sample of patients. Methods: This is a retrospective analysis of the medical records of patients diagnosed with NTMLD treated in a referral center located in the city of Porto Alegre, Brazil, between 2003 and 2013. Results: Our sample comprised 100 patients. The most prevalent NTM species were Mycobacterium avium complex (MAC), in 35% of the cases; M. kansasii, in 17%; and M. abscessus, in 12%. A total of 85 patients had received previous treatment for tuberculosis. Associated conditions included structural abnormalities in the lungs, such as bronchiectasis, in 23% of the cases; COPD, in 17%; and immunosuppressive conditions, such as AIDS, in 24%. Conclusions: MAC and M. kansasii were the most prevalent species involved in NTMLD in the state, similarly to what occurs in other regions of Brazil. Data on regional epidemiology of NTMLD, its specific etiology, and associated conditions are essential to establish appropriate treatment, since each species requires specific regimens. Most patients with NTMLD had received previous tuberculosis treatment, which might lead to development of resistance and late diagnosis.

Keywords: Nontuberculous mycobacteria; Mycobacterium infections, nontuberculous; Lung diseases.

Objective: To describe the trends in tumor histology, gender and age among patients with non-small cell lung cancer (NSCLC) treated with lung resection. The histology of lung cancer has changed in developed countries, and there is still little information available on the topic for developing countries. Methods: This was a retrospective study of 1,030 patients with NSCLC treated with lung resection between 1986 and 2015 at a university hospital in southern Brazil. Differences in histology, stage, and type of surgery were analyzed by gender and for three periods (1986-1995, 1996-2005, and 2006-2015). Results: Most (64.5%) of the patients were males, and the main histological types were squamous cell carcinoma (in 40.6%) and adenocarcinoma (in 44.5%). The mean age at surgery during the first period was 56.4 years for women and 58.9 years for men, compared with 62.2 for women and 64.6 for men in the third period (p < 0.001). The proportion of females increased from 26.6% in the first period to 44.1% in the third. From the first to the third period, the proportion of patients with squamous cell carcinoma decreased from 49.6% to 34.8% overall (p < 0.001), decreasing to an even greater degree (from 38.9% to 23.2%) among men. Among the NSCLC patients in our sample, females with adenocarcinoma accounted for 11.9% in the first period and 24.0% in the third period (p < 0.001). Conclusions: As has been seen in developed countries, the rates of lung cancer in females in southern Brazil have been rising over the last three decades, although they have yet to surpass those observed for males in the region. The incidence of squamous cell carcinoma has decreased in males, approaching adenocarcinoma rates, whereas adenocarcinoma has significantly increased among women.

Keywords: Lung neoplasms; Epidemiology; Histology; Adenocarcinoma; Carcinoma, non-small-cell lung; Carcinoma, squamous cell.