Indications for using video-assisted thoracoscopic surgery to diagnose diaphragmatic injuries after penetrating chest trauma.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) has been shown to be an accurate method for identifying diaphragmatic injuries (DIs). The purpose of this investigation was to establish specific indications for the use of VATS after penetrating chest trauma. METHODS: A retrospective review of all patients undergoing VATS after penetrating chest trauma at a level 1 trauma center over an 8-year period was performed. Logistic regression was used in an attempt to identify independent predictors of DI. RESULTS: One hundred seventy-one patients underwent VATS assessment of a hemidiaphragm, and 60 patients (35%) were found to have a DI. Five independent risk factors for DI were identified from analyzing the patient records: abnormal chest radiograph, associated intraabdominal injuries, high-velocity mechanism of injury, entrance wound inferior to the nipple line or scapula, and right-sided entrance wound. CONCLUSIONS: In the largest published series of patients undergoing VATS to exclude a DI, this review identifies five independent predictors of DI after penetrating chest trauma. A diagnostic algorithm incorporating these five factors was designed with the goal of reducing the number of unrecognized DIs after penetrating chest trauma by using VATS for patients at greatest risk for such injuries.

Comparative study of solutions for pulmonary preservation using an isolated rabbit lung model.

At the University of Minnesota, University of Wisconsin (UW), modified Euro-Collins (MEC), and Marshall (M) solutions were compared as agents for pulmonary preservation in an isolated rabbit lung model. Normal saline (NS) was used as a control. The heart-lung blocks of donor rabbits were flushed with, and then preserved in, one of the solutions at 4 degrees C. Five rabbits were studied in each group. After 8 h of cold ischemia, the left lung was ventilated and reperfused with fresh venous blood from donor rabbits for 30 min. Pulmonary function was assessed by serial measurements of oxygen (O2) and carbon dioxide (CO2) tensions in blood obtained from the left atrial appendage. The ratios of wet/dry (W/D) weight of the lungs were calculated to assess the extent of pulmonary edema. After 8 h of preservation followed by 30 min of reperfusion, O2 tension was significantly higher with UW (178.36 + 1.72 mmHg). The calculated P values were UW vs NS, < 0.0001; UW vs MEC, 0.154; and UW vs M, 0.0001. CO2 tension with UW was also lower than the other solutions: UW, 35.8 +/- 0.698 mmHg; NS, 48.5 +/- 0.745 mmHg; MEC, 40.69 +/- 0.749 mmHg; and M, 44.68 +/- 0.697 mmHg. The calculated P value was UW vs NS, 0.0001; UW vs MEC, 0.0003; and UW vs M, 0.0001 using repeated-measures analysis of covariance. The W/D ratio was lower with UW as well; UW, 6.82 +/- 0.19; NS, 8.01 +/- 0.23; MEC, 7.28 +/- 0.10; and M, 7.34 +/- 0.17. The P value was < 0.001 using post-hoc tests. In this model, UW solution preserved the lungs better than the other three solutions tested and therefore warrants further clinical application.

Experimental large-animal model of obliterative bronchiolitis after lung transplantation.

Obliterative bronchiolitis is a major cause of long-term morbidity after lung transplantation. It is characterized by small-airway inflammation and occlusion by fibrous tissue. The pathogenesis is uncertain. To study this disease, we developed a model of posttransplantation obliterative bronchiolitis using genetically defined miniature swine. Group 1 (n = 2) received a left lung autograft; group 2 (n = 7), a left lung allograft. Group 2 recipients were given cyclosporine, prednisone, and azathioprine for 3 months, then immunosuppression was tapered and discontinued over 1 month. The animals were observed for an additional 2 months, then sacrificed. Lung grafts in both groups were monitored with serial bronchoalveolar lavages and transbronchial biopsies for 6 months. After sacrifice, lung grafts underwent histopathologic and immunohistochemical examination. No allograft had histologic evidence of acute rejection or peribronchiolar infiltrate during the first 3 months of immunosuppression. During the tapering period, airway changes characterized by severe peribronchiolar lymphocytic infiltrates were seen. Bronchoalveolar lavages of allografts showed significantly increased lymphocyte counts with CD8+ cells predominating. After the discontinuation of immunosuppression, transbronchial biopsy and autopsy specimens showed progressive fibrous inflammatory occlusion of bronchioles. Immunohistochemical staining demonstrated increased expression of MCH class II antigen on the bronchiolar epithelium and increased dendritic cells and CD4+ lymphocytes. None of these changes were seen in group 1. Our findings suggest obliterative bronchiolitis is an immunologically mediated phenomenon related to chronic graft rejection after lung transplantation. This model will allow systematic study of the pathogenesis of obliterative bronchiolitis and possible therapeutic intervention.