The authors report a case of recurrent pneumothorax secondary to agenesis of the diaphragm in a 36-year old female. The diagnosis was established by means of clinical history and chest X-ray examination. Surgical correction was carried out. Diaphragmatic agenesis was detected during the procedure and pleural abrasion was performed. Two months following surgery another pneumothorax episode occurred. Fallopian tube ligature was then performed in order to prevent the entrance of air into the abdomen during ovulation, and thus avoid further recurrences of pneumothorax.

Keywords: Diaphragm. Agenesis. Pneumothorax. Recurrence.

Background: Pulmonary hypertension secondary to chronic thromboembolism is a severe and debilitating disease and has been associated with high mortality. Pulmonary thromboendarterectomy is the treatment of choice. Objective: To evaluate the impact of pulmonary thromboendarterectomy on the quality of life of patients with pulmonary hypertension secondary to chronic thromboembolism using the SF-36 Health Survey. Method: The SF-36 Health Survey questionnaire was administered to 13 patients prior to and at least 3 months following thromboendarterectomy. Results: Of the 13 patients studied, 7 were female and 6 were male. Mean age was 45.7 ± 18.3. All were submitted to thromboendarterectomy. After surgery, all SF-36 domains, with the exception of the "mental health" domain, improved. Conclusion: Pulmonary thromboendarterectomy provides significant improvement in patient quality of life.

Keywords: Key words: Hypertension pulmonary. Pulmonary embolism. Endarterectomy/methods. Quality of life.

Pectus excavatum (PEX) is the most frequent congenital deformity of the anterior chest wall and is defined as the dislocation of the medial or inferior portion of the sternal region toward the spinal column. There are various ways to measure the deformity. In this study, we present an objective method of assessing such deformity, the anthropometric index for PEX (AI-PEX). The AI-PEX was developed in the Thoracic Surgery Department of the Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas. The anthropometric measurements are taken during the physical examination. We herein report two cases involving patients with PEX assessed using the AI-PEX and treated with the minimally invasive Nuss technique. The measurements were always taken at the point of greatest deformity. The patients were assessed on the day of the operation and again at 60 days after the surgery. The AI-PEX allowed us to obtain a satisfactory assessment of the defect. In both patients, the post-operative evolution was favorable.

Keywords: Thoracic wall; Thoracic surgery, Video-assisted; Funnel chest.

Objective: To evaluate the Polyflex® stent in terms of its efficacy, ease of implantation, and complications in patients with tracheobronchial affections. Methods: This was a prospective study, in which sixteen patients with inoperable tracheal stenosis secondary to orotracheal intubation (n = 12), neoplasia (n = 3), or Wegener's granulomatosis (n = 1) were monitored. Of these patients, eleven were women, and five were men. The mean age was 42.8 years (range, 21-72 years). Patients were submitted to implantation of a total of 21 Polyflex® stents. All procedures were carried out in the operating room under general anesthesia, and the stents were implanted via suspension laryngoscopy using the stent applicator. Results: Stents were implanted and symptoms were resolved in all cases. The stents remained in place for a mean period of 7.45 months, ranging from 2 to 18 months. The complications observed in the immediate postoperative period were dysphonia (in two patients, 12.5%) and odynophagia (in two patients, 12.5%). Late complications were cough (in ten patients, 62.5%), migration (in seven patients, 43.75%), granuloma formation (in two patients, 12.5%), and pneumonia (in one patient, 6.25%). Conclusion: The Polyflex® stent is easily implanted, easily removed, well tolerated by patients and effective in resolving symptoms. However, its use is associated with a high rate of migration, especially in patients with post-orotracheal intubation stenosis.

Keywords: Tracheal stenosis; Intubation, intratracheal; Prostheses and implants; Stents.

Fistulas in the tracheobronchial tree (bronchopleural and tracheoesophageal fistulas) have a multifactorial etiology and present a variable incidence in the literature. In general, the related morbidity and mortality are high. Once such a fistula has been diagnosed, surgical closure is formally indicated. However, the clinical status of affected patients is usually unfavorable, which precludes the use of additional, extensive surgical interventions. In addition, attempts at endoscopic closure of these fistulas have seldom been successful, especially when the fistula is large in diameter. We report the cases of three patients submitted to endoscopic closure of fistulas, two of which were larger than 10 mm in diameter, by means of the insertion of atrial septal defect occluders. The procedure was minimally invasive, and the initial results were positive. The results indicate that this is a promising technique for the resolution of tracheobronchial tree fistulas.

Keywords: Bronchial fistula; Tracheoesophageal fistula; Bronchoscopy; Respiratory therapy.

Objective: To evaluate the effects of azathioprine on the mucociliary system in a model of bronchial section and anastomosis in rats. Methods: Thirty-six male Wistar-Furth rats were submitted to left bronchial section and anastomosis and divided into two groups to receive either saline solution or azathioprine. After 7, 15 and 30 days of treatment, six animals from each group were killed, after which in situ mucociliary transport velocity, in vitro mucus transportability, and contact angle of mucus in the right (intact) and left (sectioned) bronchi were measured. Results: In situ mucociliary transport velocity was significantly lower in the sectioned bronchi than in the intact bronchi (p < 0.001). In situ mucociliary transport velocity was lower in the intact bronchi of the animals treated with azathioprine for 7 days (p < 0.05), and those bronchi presented full recovery after 30 days of treatment. The contact angle was higher in the mucus samples collected from the sectioned bronchi of the animals treated with saline solution for 30 days (p < 0.001), which is in accordance with the decreased in vitro mucus transportability observed in the same animals (p < 0.001). Conclusions: We conclude that, in the sectioned bronchi of rats, treatment with azathioprine causes only transitory impairment of mucociliary transport, whereas administration of saline solution impairs mucociliary transport for up to 30 days. In addition, azathioprine protects against alterations in mucus surface properties.

Keywords: Mucociliary clearance; Anastomosis, surgical; Immunosuppression; Lung.

Sclerosing mediastinitis is a rare disorder characterized by an extensive fibrotic reaction involving the mediastinum. Due to the compression or invasion of mediastinal structures, the disorder mimics neoplasia. We present three cases of superior vena cava syndrome in which sclerosing mediastinitis was confirmed. The pathophysiological process is related to enlarged mediastinal lymph nodes, fibroblast proliferation and collagen deposition. The main causes of sclerosing mediastinitis are histoplasmosis and tuberculosis, both of which are prevalent in Brazil. It is difficult to make an accurate histopathological diagnosis using minimally invasive methods, and there is no effective treatment for this condition. In order to make a definitive diagnosis and resolve the aerodigestive tract obstruction, exploratory surgery is indicated.

Keywords: Mediastinitis/physiopathology; Mediastinum; Pulmonary fibrosis; Mediastinal neoplasms; Diagnosis, differential; Case reports [Publication type].

Pulmonary hypertension secondary to thromboembolism is a serious and debilitating disease. It occurs in approximately 0.5-1.0% of patients who survive an episode of acute thromboembolism. This is the first reported case of successful thromboendarterectomy performed in an elderly patient in Brazil. The patient, an 80-year-old man, presented favorable postoperative evolution. The authors believe this surgical procedure is a viable option for treatment of this type of pulmonary hypertension even in patients of advanced age, providing that there are no comorbidities.

Keywords: Thromboendarterectomy/methods. Hypertension pulmonary/surgery. Clinical evolution.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a new method for the diagnosis and staging of mediastinal lymph nodes. The objective of this study was to evaluate the preliminary results obtained with EBUS-TBNA in the diagnosis of lesions and mediastinal lymph node staging. Methods: We evaluated patients with tumors or mediastinal adenopathy, diagnosed with or suspected of having lung cancer. The procedures were performed with the patients under sedation or under general anesthesia. Material was collected by EBUS-TBNA, after which it was prepared on slides, fixed in either absolute alcohol (for cytology) or formalin (for cell-block analysis). Results: We included 50 patients (30 males). The mean age was 58.3 ± 13.5 years. We performed 201 biopsies of 81 lymph nodes or mediastinal masses (mean of 2.5 punctures/biopsy). The quantity of material was considered sufficient for cytology in 37 patients (74%), 21 (57%) of whom were thus diagnosed with malignancy. Of the remaining 16 patients, 1 was diagnosed with tuberculosis, 6 entered clinical follow-up, and 9  underwent further investigation (2 diagnosed with neoplasm-false-negative results). The yield was higher when the procedure was performed for diagnostic purposes, as well as being higher in patients with lesions in multiple stations and in biopsies involving the subcarinal lymph node station. One patient had endobronchial bleeding, which was resolved with local measures. There were no deaths among the patients evaluated. Conclusions: This preliminary experience shows that EBUS-TBNA is a safe procedure. Our diagnostic yield, although lower than that reported in the literature, was consistent with the learning curve for the method.

Keywords: Ultrasonography, interventional; Biopsy, fine-needle; Neoplasm staging; Lung neoplasms; Bronchoscopy.

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.

Objective: To evaluate the experience in diagnosing and treating malignant pleural mesothelioma (MPM) accumulated over 5 years in a tertiary public hospital. Methods: The medical charts of the patients diagnosed with MPM between January of 2000 and February of 2005 were evaluated retrospectively. Results: Of the 17 patients analyzed, 14 were male and 3 were female. The mean age was 54.1 years (range, 13-75 years). The biopsy specimens for histopathological examination were obtained through thoracoscopy in 9 patients (53%), Cope needle in 5 (29.5%), and open pleural biopsy in 3 (17.5%). The following histological types were identified: epithelial, in 14 patients (82%); sarcomatoid, in 1 (6%); and biphasic, in 2 (12%). The therapeutic approaches used were as follows: multimodal (pleuropneumonectomy and adjuvant radiotherapy and chemotherapy) in 6 patients (35%); chemotherapy and radiotherapy in 6 (35%); radiotherapy alone in 3 (17.5%); and chemotherapy alone in 2 (12%). The mean survival was 11 months (range, 1-26 months). Conclusions: In the cases studied, an integrated multidisciplinary approach was used, and a highly complex hospital infrastructure was available for the diagnosis and treatment of MPM, as recommended in the literature. However, the mean survival was only 11 months, reflecting the aggressiveness of the disease.

Keywords: Mesothelioma; Pleura; Surgery; Diagnosis.

Objectives: To describe a group of patients with thymoma who were submitted to surgica treatment associated or not with therapy, and evaluate their prognosis. Methods: Of the 104 patients with thymic tumors who were operated at Hospital das Clínicas - São Paulo University Medical School between 1965 and 1998, (66.3%) were males. Mean age at diagnosis, was 47.9% ± 16.3 years (ranging from 13 to 76 years). Results: Of the 104 patients, 89 (85.6%) underwent complete thymoma resection, 6 (5.8%) underwent partial resection and, in 9 (8.6%) of them, biopsy was performed. Anatomopathologic diagnosis (thymoma vs malignant thymoma) and the type of surgery (biopsy vs complete resection vs partial resection) were significant predictors of survival mean time (p < 0.02). Conclusions: Complete resection is the treatment of choice for thymomas. These tumors, when not invasive and completely resected, have good immediate and late prognosis.

Keywords: Thymoma.

Background: Pulmonary sequestration is a congenital anomaly involving the pulmonary parenchyma and its vascularization, and it presents as extralobar or intralobar. Aim: Describe the cases treated at the Institute of Heart (InCor) and Clinical Hospital of the Medical School of the University of São Paulo (FMUSP). Method: Retrospective analyses of the files of the patients treated over the 10-year period taking demographic, clinical and laboratorial data. Results: The patients were recurrent pulmonary infection and hemoptysis were frequent clinical findings in these patients. All cases were intralobar. The main localization was the left lower lobe (66%). Only one diagnosis was made intra-operatively. In the other eight cases, diagnosis was suggested on chest radiographs (100%) and confirmed by angiography (77%) and computed tomography (66%). Lobectomy (77%) was the most common surgical treatment, with low post-operative morbidity, and no mortality. Anatomic and histologic examination was performed in seven cases and confirmed the pathology. Conclusion: Pulmonary sequestration is an uncommon entity, in which the computed tomography and the angiography are the radiological investigations that provide the most information to a definitive and secure diagnosis. Resection of the involved tissue leads to excellent results.

Objective: To analyze the rate at which lungs available for transplantation in the state of São Paulo in 2006 were utilized and to determine the lung donor profile in the same period. Methods: A retrospective study of 497 clinical charts of lung tissue donors from January to December of 2006. Results: According to the clinical charts, lungs were not offered for transplant in 149 cases (30%), which were therefore excluded from the study. Among the 348 lung donors eligible for inclusion in the study, the mean age was 37.4 ± 16.1 years, and 56.9% were males. The main causes of brain death among the donors were stroke (in 40.5%), skull-brain trauma (in 34.2%) and subarachnoid hemorrhage (in 10.9%). The great majority of these lung donors (90.5%) received vasoactive agents, and 13.5% presented cardiopulmonary arrest. The mean donor leukocyte count was 15,008 ± 6,467 cells/mm3, 67.8% of the donors received anti-bacterial agents, and 26.1% presented lung infection. Nearly 40% of the lung donors presented chest X-ray abnormalities. Only 4.9% of the lung donors were accepted, representing 28 lungs (allograft utilization rate of 4%). The causes for donor exclusion were gas exchange alterations (in 30.1%), infection (in 23.7%) and distance (in 10.9%). Conclusions: The lung utilization rate in the state of São Paulo is low when compared to mean rates worldwide. In addition, more than half of the donor pool was excluded due to altered gas exchange or pulmonary infection. The combination of better care of the potential donor and more flexible selection criteria could increase allograft utilization.

Keywords: Lung transplantation; Donor selection; Tissue donors.

Objective: To evaluate the use of video-assisted thoracoscopy in the surgical treatment of chylothorax developed after the surgical correction of congenital heart disease in children. Methods: We reviewed the medical charts of 3,092 children who underwent surgery for congenital heart disease between February of 2002 and February of 2007 at the Heart Institute of the University of São Paulo School of Medicine Hospital das Clínicas, in São Paulo, Brazil. Results: Of the 3,092 children, 64 (2.2%) presented with chylothorax as a postoperative complication. In 50 (78.1%) of those patients, the clinical management was successful, whereas it failed in 14 (21.9%), all of whom were then submitted to thoracic duct ligation by video-assisted thoracoscopy. The thoracic duct ligation was successful in 12 patients (86%) but failed in 2. In the postoperative period, additional clinical measures, such as a low-fat diet and parenteral nutrition, were required in order to resolve those 2 cases. There was no surgical morbidity or mortality. Of the 14 patients who underwent thoracic duct ligation, 5 (35%) died due to cardiac or infectious complications. Conclusions: Video-assisted thoracic duct ligation can be safely performed in patients with severe heart disease, and the outcomes are favorable.

Keywords: Chylothorax; Heart defects, congenital; Thoracic duct.

Objective: Heimlich valve has been described as a substitute for water-sealed drainage systems. The objective of this study by the Thoracic Surgery Service of the "Hospital das Clínicas", University of São Paulo Medical Center, is to assess its effectiveness in the treatment of pneumothorax and its ease of operation, safety, and patient toleration. Methods: From June/97 to August/00, 107 patients with pneumotoraxes of different etiologies were analyzed. The majority (76%) were classified radiologically as suffering from moderate or large pneumothorax, three hypertensive pneumothorax, and one was bilateral. The pleural cavity was drained with teflon or polyurethane plastic pig-tail catheters (10.2F, 14F, straight 11F connected to the Heimlich valve or the valve was connected directly to the thoracic drain in post-thoracotomy patients). Results: The valve remained in place for one to 120 days (mean 4 days). Tolerance to the system was good in 89% of cases. There were no serious complication linked to the system. Associated pleural effusion in 20 patients (18.5%) did not prevent the system from functioning well. Only two patients (1.8%) developed subcutaneous emphysema, and therefore, a 36F Tubular drain under water seal was chosen. Thoracotomy for decortication was indicated in one patient (0.9%). Twenty patients (18.5%) were treated on an outpatient basis. Conclusions: The Heimlich valve confirmed its effectiveness in resolving pneumothorax of different etiologies and in postoperative air leaks. Its operation was simpler than that of conventional systems. The good toleration and safety mentioned by the patients was a determining factor in early hospital discharge and a motive for outpatient treatment.

Keywords: Pneumothorax. Pleura. Postural drainage.

Objective: To analyze the outcomes of patients undergoing repair of congenital tracheal stenosis. Methods: This was a retrospective review of congenital tracheal stenosis patients treated between 2001 and 2007 at the University of São Paulo School of Medicine Hospital das Clínicas in São Paulo, Brazil. Results: Six boys and one girl (age at diagnosis ranging from 28 days to 3 years) were included. Five of the patients also had cardiac or major vessel malformations. The stenosis length was short in three patients, medium in one and long in three. The techniques used were pericardial patch tracheoplasty in three patients, resection and anastomosis in two, slide tracheoplasty in one and vascular ring correction in one. One patient died during surgery due to hypoxia and hemodynamic instability, and one died from septic shock on postoperative day 11. Other complications included pneumonia, arrhythmia, stenosis at the anastomosis level, residual stenosis, granuloma formation and malacia. The mean follow-up period was 31 months; four patients were cured, and one required the use of a T-tube to maintain airway patency. Conclusions: Congenital tracheal stenosis is a curable disease. However, its repair is complex and is associated with high rates of morbidity and mortality.

Keywords: Tracheal stenosis/congenital; Tracheal diseases; Surgical procedures, operative.

Objective: To create a reference map of mediastinal lymph nodes through the analysis of their size, number and distribution in various lymph node stations. Method: A total of 50 cadavers, 38 males and 12 females, were studied. Of those 50, 39 were Caucasian. The mean age was 59.9 ± 14.1 years, the mean height was 173.1 ± 7.6 cm, and the mean weight was 71.0 ± 12.0 kg. A bilateral mediastinal dissection was performed in order to resect and isolate all lymph nodes. The area, as well as the major and minor transverse diameters, of each lymph node was determined by radiographic imaging analysis. Results: In a sample of 485 chains, 1742 lymph nodes were dissected (2.58 ± 1.89 lymph nodes/station), revealing a mean number of 21.2 ± 8.5 lymph nodes on the right and 13.6 ± 6.3 on the left. The lymph node stations 1, 2R, 4R, 5, and 7 were present in more than 90% of the sample. Only the 4R and 7 lymph node stations were always present. The lymph node stations 2L, 3p, and 8 were present in 32, 36, and 54% of the sample, respectively. Mediastinal lymph nodes were present in greater numbers in the 2R, 4R and 7 lymph node stations. In addition, these stations presented the largest mediastinal lymph nodes. Conclusion: Composing a reference map for lymph node sizes was feasible. No alterations were observed in the distribution, number, or size of lymph nodes in the age brackets studied, regardless of gender, race, weight, or height.

Keywords: Lymph nodes; Mediastinum; Cadaver; Anatomy.

Background: Lung volume reduction surgery may be a viable treatment alternative for emphysema patients suffering from severe respiratory insufficiency. Objectives: To evaluate functional and morphological aspects of emphysematous rat lungs, prior to and following lung volume reduction surgery. Method: Wistar rats were divided into two experimental groups (papain without surgery and papain with surgery) and three control groups (saline without surgery, saline with surgery and papain without mechanical ventilation). After approximately 40 days of endotracheal instillation of papain or saline solution, animals in the papain with surgery and saline with surgery groups were submitted to bilobectomy of the middle lobes by right thoracotomy along the posterior border of the superior vena cava. After 1 week, the same animals were submitted to a mechanical ventilation study, which involved measurement of lung elasticity and airway resistance. For all of the animals studied, lung tissue was analyzed in order to determine alveolar diameter and the elastic fiber quantity. Results: Morphometric analysis revealed higher mean alveolar diameter in the lungs of all animals exposed to papain as compared to those exposed to saline. Elastic fiber counts in the alveolar septa of animals treated with papain were lower than those of animals receiving saline. In the animals submitted to bilobectomy and papain, lung elasticity was greater than in those receiving papain without surgery and was statistically equal to that seen in animals receiving saline (with or without surgery). Conclusion: In the respiratory systems of animals with pulmonary emphysema submitted to lung volume reduction by bilobectomy, the capacity for elastic recoil returned to values equivalent to those of the control group animals.

Keywords: Key words: Pulmonary emphysema. Papain/drugs efects. Case-control studies. Disease models, animal. Respiratory mechanics/drugs efects. Lung/sugery. Lung/anatomy & histology.

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.

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.

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.

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.

Keywords: Trachea; Dilatation; Thoracic Surgery; Laryngoscopy.

Despite preventive measures, lung hyperinflation is a relatively common complication following single lung transplantation to treat pulmonary emphysema. The progressive compression of the graft can cause mediastinal shift and respiratory failure. In addition to therapeutic strategies such as independent ventilation, the treatment consists of the reduction of native lung volume by means of lobectomy or lung volume reduction surgery. We report two cases of native lung hyperinflation after single lung transplantation. Both cases were treated by means of lobectomy or lung volume reduction surgery.

Keywords: Lung transplantation; Postoperative complications; Pulmonary emphysema; Pneumonectomy.

Objectives: Thoracoscopic management of mediastinal tumors is still subject to analysis. Seventy-three patients were submitted to thoracoscopy for the treatment of mediastinal masses and were analyzed retrospectively, in order to evaluate the effectiveness and complications of the procedure. Methods: Between 1983 and 1999, 21 conventional thoracoscopies and 52 video-assisted thoracic surgeries were performed (33 for diagnostic purposes and 40 for therapy). Patient ages ranged from two to 81 years (mean 43.8) with a slight predominance of females over males (41 versus 32). All underwent general anesthesia using simple (22) or double lumen (51) intubation. Results: The histological type of tumor was identified in all patients. For therapeutic purposes, conversion to thoracotomy was necessary in nine patients. The reasons were tumor size and invasion of nearby structures, difficulty to continue dissection, to perform an upper lobectomy, and to suture the iatrogenic diaphragm lesion. Four patients died during the first 30 postoperative days as a consequence of their primary pathology. Conclusions: Thoracoscopy was confirmed to be an effective diagnostic and therapeutic alternative for the treatment of mediastinal disorders.

Keywords: Thoracoscopy, thoracic surgery, mediastinal neoplasms, mediastinal cysts.

Objective: The reproduction of an experimental emphysema model in rats by intratracheal instillation of papain was proposed for the evaluation of lung volume reduction surgeries. Method: The study used orotracheal instillation of papain (20 mg/kg) dissolved in 0.9% saline solution. Forty days after instillation, animals underwent mechanical ventilation. Elastance and resistance of the respiratory system were measured, and the rats were sacrificed by having their lungs removed. The pulmonary tissue of the animals was qualitatively analyzed with hematoxylineosin staining and submitted to morphometric analysis for the measurement of the mean alveolar diameter. The pulmonary tissue was also subjected to resorcin-fuchsin staining for the identification of elastic fibers, which were quantified in alveolar septa by digital imaging. Results: In the animals instilled with papain, the histological analysis of the lungs showed pan-acinar emphysema, with rupture of alveolar septa and hyperdistention. Morphometric analysis showed higher mean values for mean alveolar diameter in the lungs of the animals submitted to papain (149.08 μm and 100.56 μm) as compared to the group receiving saline solution (64.08 μm and 75.90 μm). The quantification of elastic fibers of alveolar septa of papain-treated animals was 70% lower than in the animals receiving saline solution. Mechanic ventilation did not show differences in respiratory system resistance of animals receiving papain or saline solution. Respiratory system elastance was lower in the group receiving papain than in the group receiving saline solution, showing a functional status compatible with pulmonary emphysema, with decreased elasticity of the pulmonary tissue. Conclusion: The reproduction of an experimental model of pan-acinar pulmonary emphysema in rats was achieved by papain instillation through the respiratory tree with functional and morphologic evidences.

Keywords: Pulmonary emphysema. Experimental model. Papain. Rats. Drug instillations.