Congenital lung malformations are rare and vary widely in their clinical presentation and severity, depending mostly on the degree of lung involvement and their location in the thoracic cavity. They can manifest at any age and can be the source of significant morbidity and mortality in infants and children. Individuals with congenital lung malformations can present with respiratory symptoms at birth or can remain asymptomatic for long periods. Recently, there has been an increase in the early diagnosis of these malformations, a change that is attributable to the routine use of prenatal ultrasound. The clinical manifestation of these malformations varies from respiratory distress in the immediate postnatal period to an incidental finding on chest X-rays. Early diagnosis and prompt treatment offer the possibility of absolutely normal lung development. The treatment of asymptomatic patients with lung malformations is controversial, because the prognosis of these diseases is unpredictable. The management of these lesions depends on the type of malformation and symptoms. Because of the risk of complications, most authors recommend resection of the lesion at the time of diagnosis. Lobectomy is the procedure of choice and yields excellent long-term results. This article describes the principal congenital lung malformations, their diagnosis, and the controversies regarding treatment.

Keywords: Cystic adenomatoid malformation of lung, congenital; Bronchopulmonary sequestration; Pulmonary surgical procedures; Diagnosis.

Mucoepidermoid carcinoma is an uncommon neoplasm of the tracheobronchial tree, of unknown etiology. Its preferred endobronchial location often results in respiratory symptoms such as obstruction of the airways and lung diseases of slow recovery. They usually are slow growing tumors although they may present an aggressive behavior with local invasion and lymph node metastases depending on their histopathologic characteristics. The mainstay therapy is complete surgical resection either by means of lobectomy or by lung sparing procedures such as bronchotomy and bronchoplasty. Prognosis depends upon the degree of cellular differentiation of the tumors. The authors report a case of this rare neoplasia and describe the clinical and radiographic characteristics, and the surgical treatment.

New methods of ventilation are being studied in different settings of pulmonary insufficiency in which the ultimate goal is to improve gas exchange and to minimize aggression to the lung parenchyma. The use of liquid perfluorocarbons administered directly in the airways has been ostensibly studied in pulmonary lesion models and in some clinical essays with good results relating to gas exchange, ventilatory mechanics, and anti-inflammatory properties. PFCs are substances with low surface tension, high density, they are not soluble in water, and allow for high diffusion of oxygen and carbonic gas. They act by recruiting collapsed alveoli, improving the gas exchange, protecting pulmonary architecture, and they wash out alveoli debris. This review article focuses on the different liquid ventilation strategies with perfluorocarbons, and provides information on the state of the art of liquid ventilation.

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.

Objective: To determine the main congenital lung malformations treated and the principal diagnostic methods employed, as well as the indications for surgical treatment and the results obtained, at a referral facility for pediatric thoracic surgery. Methods: We reviewed the medical charts of 52 patients anatomopathologically diagnosed with congenital lung malformations and who had been submitted to pulmonary resection between January of 1997 and December of 2006. Exclusion criteria were age ≥ 12 years and incomplete clinical data. The final sample comprised 35 patients. Results: In this sample, the mean age was 31 months, and there was a predominance of males (n = 21). The anatomopathological findings were cystic adenomatoid malformation (n = 14), congenital lobar emphysema (n = 13), pulmonary sequestration (n = 8) and arteriovenous malformation (n = 1). The most common type of lung resection was left lower lobectomy (in 25.71%) followed by different types of segmentectomy (in 22.85%), left upper lobectomy (in 22.85%), right upper lobectomy (in 14.28%), right lower lobectomy (in 8.57%) and middle lobectomy (in 5.71%). Of the 35 patients, 34 (97.14%) were submitted to closed pleural drainage, with a mean duration of thoracic drainage of 3.9 days. Ten patients (28.5%) presented with postoperative complications. There were no deaths in our sample. Conclusions: Pulmonary resection for the treatment of congenital lung malformations is a safe procedure, presenting low morbidity and no mortality at a referral facility for pediatric thoracic surgery.

Keywords: Cystic adenomatoid malformation of lung, congenital; Bronchopulmonary sequestration; Pneumonectomy; Pulmonary surgical procedures; Pulmonary emphysema.

Background: Bronchiectasis is a frequently found disease in medical practice in Brazil leading to significant morbidity and decrease in quality of life of the affected individuals. Objectives: To study diagnostic and therapeutic aspects in a series of hospitalized patients with bronchiectasis in a department of pulmonary diseases. Methods: Signs, symptoms, microbiological and radiographic data, and therapeutic results were studied in 170 hospitalized patients between 1978 and 2001 - females 62.4%, males 37.6%, and aged from 12 to 88 years (mean age 36.8 yrs). Previous history of pneumonia in childhood was detected in 52.5% of the patients, tuberculosis in 19.8%; 8.8% had bronchial asthma, and 2 had Kartagener's syndrome. Results: The most common symptoms were cough (100.0%), expectoration (96.0%) and pulmonary rales (66.0%). The pulmonary lesions were unilateral in 46.5% of the cases. Pneumococcus, H. influenzae or mixed flora were found in 85.0% of the examined sputa. All 170 patients received antibiotics and postural drainage, and 88 of them (younger and with a higher functional reserve) were also submitted to pulmonary resections (82 unilateral and 6 bilateral). Two deaths occurred, and repetitive hospitalizations were more frequent among the clinically treated patients. The follow up showed that most of the surgically treated patients had significant symptoms improvement and rarely needed to be re-hospitalized. Conclusions: In the majority of the patients, lung resection surgery improved permanently the prolonged bronchopulmonary symptoms of patients with bronchiectasis, differently from the patients who received only clinical treatment.

Keywords: Bronchiectasis/diagnosis. Bronchiectasis/therapy. Bronchiectasis/surgery. Bronchiectasis/complications. Tomography X-ray computed/methods. Inpatients. Retrospective studies.

Objective: To assess the esophageal function profile and the prevalence of gastroesophageal 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.

Keywords: Gastroesophageal reflux; Lung transplantation; Manometry; Esophageal pH monitoring.

Objective: To evaluate post-operative complications in living lobar lung transplant donors. Methods: Between September of 1999 and May of 2005, lobectomies were performed in 32 healthy lung transplant donors for 16 recipients. The medical charts of these donors were retrospectively analyzed in order to determine the incidence of post-operative complications and alterations in pulmonary function after lobectomy. Results: Twenty-two donors (68.75%) presented no complications. Among the 10 donors presenting complications, the most frequently observed complication was pleural effusion, which occurred in 5 donors (15.6% of the sample). Red blood cell transfusion was necessary in 3 donors (9.3%), and 2 donors underwent a second surgical procedure due to hemothorax. One donor presented pneumothorax after chest tube removal, and one developed respiratory infection. There were two intra-operative complications (6.25%): one donor required bronchoplasty of the middle lobe; and another required lingular resection. No intra-operative mortality was observed. Post-operative pulmonary function tests demonstrated an average reduction of 20% in forced expiratory volume in one second (p < 000.1) compared to pre-operative values. Conclusions: Lobectomy in living lung transplant donors presents high risk of post-operative complications and irreversible impairment of pulmonary function. Careful pre-operative evaluation is necessary in order to reduce the incidence of complications in living lobar lung transplant donors.

Keywords: Lung transplantation; Living donors; Pneumonectomy; Postoperative complications.

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.

Keywords: Ischemia; Reperfusion; Organ preservation; Reactive oxygen species.

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.

Keywords: Pulmonary ventilation; Respiration, artificial; Lung transplantation; Dogs; Organ preservation.

Objective: To analyze the impact that comorbidities have on the postoperative outcomes in patients submitted to lobectomy for the treatment of bronchial carcinoma. Methods: A retrospective study of 493 patients submitted to lobectomy for the treatment of bronchial carcinoma was conducted, and 305 of those patients met the criteria for inclusion in the final study sample. The surgical technique used was similar in all cases. The Torrington-Henderson scale and the Charlson scale were used to analyze comorbidities and to categorize patients into groups based on degree of risk for postoperative complications or death. Results: The postoperative (30-day) mortality rate was 2.9%, and the postoperative complications index was 44%. Prolonged air leakage was the most common complication (in 20.6%). The univariate analysis revealed that gender, age, smoking, neoadjuvant therapy and diabetes all had a significant impact on the incidence of complications. The factors found to be predictive of complications were body mass index (23.8 ± 4.4), forced expiratory volume in one second (74.1 ± 24%) and the ratio between forced expiratory volume in one second and forced vital capacity (0.65 ± 0.1). The scales employed proved efficacious in the identification of the risk groups, as well as in drawing correlations with morbidity and mortality (p = 0.001 and p < 0.001). In the multivariate analysis, body mass index and the Charlson index were found to be the principal determinants of complications. In addition, prolonged air leakage was found to be the principal factor involved in mortality (p = 0.01). Conclusion: Reductions in forced expiratory volume in one second, in the ratio between forced expiratory volume in one second and forced vital capacity, and in body mass index, as well as a Charlson score of 3 or 4 and a Torrington-Henderson score of 3, were associated with a greater number of postoperative complications in patients submitted to lobectomy for the treatment of bronchial carcinoma. Air leakage was found to be strongly associated with mortality.

Keywords: Lung neoplasms/surgery; Postoperative complications; Pneumonectomy; Morbidity

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

Every year, a large number of individuals become dependent on mechanical ventilation because of a loss of diaphragm function. The most common causes are cervical spinal trauma and neuromuscular diseases. We have developed an experimental model to evaluate the performance of electrical stimulation of the diaphragm in rabbits using single-channel electrodes implanted directly into the muscle. Various current intensities (10, 16, 20, and 26 mA) produced tidal volumes above the baseline value, showing that this model is effective for the study of diaphragm performance at different levels of electrical stimulation.

Keywords: Rabbits; Diaphragm; Electric stimulation; Models, animal.