Complicacoes da reimplantacao pulmonar (estudo experimental)

A study was carried out to clarify certain aspects of the complications of lung transplant. To this end, the reimplantation of the left lower lobe was perforned on twenty dogs with the intention of reducing the functional effect resulting from the operation and to exclude the influence of rejection. Certain aspects of the operative technique were described and assessed. The causes of the immediate death of 6 animals that succumbed to reimplantation were investigated (venous thrombosis - 4 cases; pneumothorax -1 case; hemothorax - 1 case). Long term observation was the main objective o this study. Bronchial and vascular anastomoses were assessed and their complications and those arising from them were identified: one bronchial stenosis with atelectasis of the lung lobe; one complete stenosis in the anastomotic area between the pulmonary vein and the atrial appendage; two cases of saccular bronchiectases, which affected the entire reimplanted are without any coexisting bronchial stricture. In the pulmonary artery no morphologic changes were found. However, there were shunts in some histologic sections. The evolution of bronchial vascularization, interrupted by the lobectomy and never restored during the reimplantation, was also investigated. Its continuity reestablished itself spontaneously and no changes were noted which could be caused by the brief interruption of the systemic circulation. Another five different operations were carried out in groups of twelve dogs to study the effects arising from the section and/or obstruction caused in the various components of the lobar pedicle: 1. Stripping hilar 2. Extrinsic narrowing of the bronchus 3. Ligation of the pulmonary artery 4. Stricture of the pulmonary vein 5. Pulmonary artery ligation and stricture of the bronchus and pulmonary vein Certain aspects of the probable connection between these operations and the complications of the reimplante were investigated, and the etiopathogenic role each hilar component may play in the development of the observed lesions was also analyzed. No significant changes were determined by operations 1 and 2. Operation 3 brought about a local hyper-vascularization through pre-capillary arterio-arterial shunts; lobar atelectasis occurred in two cases. As a result of operation 4, an extensive venous hilarpleural and posterior mediastinal collateral circulation developed, which drained into the right heart via the azygos vein. The most relevant lesions occurred with operation 6: 2 cases of atelectasis; 5 cases of bronchiectasis; 2 cases of bronchiectasis and cyctiform cavitations of the pulmonary lobe. The mechanisms that could have led to the bronchiectasis, observed in two groups, which occurred with the reimplantation and with the operation 5 were compared and some of the possible etiopathogenic problems were discussed. Exams carried out after twelve months confirmed the stabilization of the anastomosis, the normality of the respiratory tree and a clear absence of secretions in the bronchial lumen, even in the reimplanted lobeAvailable from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1200 Lisboa / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga