Lung transplantation for emphysema

A Quantitative Computed Tomography Analysis of Fissure Integrity and Emphysema Destruction in Japanese Patients with Severe Chronic Obstructive Pulmonary Disease

Objective Bronchoscopic lung volume reduction (BLVR) using a one-way endobronchial valve (EBV) can provide clinically meaningful benefits to chronic obstructive pulmonary disease (COPD) patients. Although the Japanese Pharmaceuticals and Medical Devices Agency approved EBVs in November 2022, information regarding the number of Japanese patients with severe COPD eligible for BLVR treatment is still lacking. We therefore screened computed tomography (CT) images of patients with severe COPD using a quantitative CT (QCT) analysis to estimate the proportion of candidates eligible for BLVR treatment with an EBV. Methods CT scans of COPD patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages 3 and 4 were retrospectively analyzed using QCT to evaluate fissure integrity and tissue destruction. The difference in volume-weighted percentage was measured using the density scores of the target lobe and ipsilateral non-target lobe at -910 Hounsfield units. The target lobe was defined as the most affected lobe, with an emphysema destruction score of >50% for each patient. Results High-resolution CT scans of 32 patients (GOLD 3=19, GOLD 4=13) were analyzed. The target lobe could not be identified in 1 patient, whereas the target lobes for 8 patients were not surrounded by fissures with ≥80% completeness. Conversely, in 13 patients, the target lobes were surrounded by fissures with >95% completeness. The remaining 10 patients had fissure completeness between 80% and 95% at the target lobes and were considered candidates for collateral ventilation assessment. Conclusion A QCT analysis showed that 23 of 32 patients with severe COPD could be considered for a thorough examination of BLVR treatment with EBV.

Outcomes of lung transplantation for chronic obstructive pulmonary disease

Introduction

Chronic obstructive pulmonary disease is a progressive airway disease that can progress to the terminal stage requiring oxygen supply. In this period, lung volume reduction therapies and/or lung transplantation may be considered. Morbidity and mortality risks due to transplant surgery and posttransplant immunosuppressive therapy show the importance of selecting the best candidates who will benefit from transplantation. In this context, BODE index criteria serve as important markers. This study aimed to analyze the outcomes of lung transplantation in patients with chronic obstructive pulmonary disease and to identify variables that may affect post-transplant clinical outcomes.

Materials and Methods

Lung transplants diagnosed with chronic obstructive pulmonary disease performed in our center between March 2013 and January 2023 were included in the study. Demographic information and both pre-op and post-op clinical data of the transplant patients were collected. The effect of BODE index criteria and other pre-transplant clinical data on short- and long-term outcomes after transplantation were investigated.

Results

During the study period, 34 lung transplants were performed for chronic obstructive pulmonary disease. One patient died during the operation, three patients received single transplants, and 30 received double transplants. Post-operative primary graft dysfunction was more common in single transplant recipients. The results were comparable between single and double transplants in terms of post-transplant pulmonary function and the development of chronic lung allograft dysfunction. BODE index criteria had no effect on early and late post-operative clinical data, however intra-operative use of extracorporeal membrane oxygenation, primary graft dysfunction, and prolonged extubation were significantly higher in recipients younger than 60 years.

Conclusion

Our study suggests that prelisting demographic and clinical data of chronic obstructive pulmonary disease patients had no significant effect on post-operative outcomes, however, intra-operative ECMO use, prolonged extubation, primary graft dysfunction (p< 0.05 for each) and chronic rejection (p> 0.05) were more common in patients who are <60 years of age. These data need to be confirmed by larger studies.

Contribution of adaptive immunity to human COPD and experimental models of emphysema

The pathophysiology of chronic obstructive pulmonary disease (COPD) and the undisputed role of innate immune cells in this condition have dominated the field in the basic research arena for many years. Recently, however, compelling data suggesting that adaptive immune cells may also contribute to the progressive nature of lung destruction associated with COPD in smokers have gained considerable attention. The histopathological changes in the lungs of smokers can be limited to the large or small airways, but alveolar loss leading to emphysema, which occurs in some individuals, remains its most significant and irreversible outcome. Critically, however, the question of why emphysema progresses in a subset of former smokers remained a mystery for many years. The recognition of activated and organized tertiary T- and B-lymphoid aggregates in emphysematous lungs provided the first clue that adaptive immune cells may play a crucial role in COPD pathophysiology. Based on these findings from human translational studies, experimental animal models of emphysema were used to determine the mechanisms through which smoke exposure initiates and orchestrates adaptive autoreactive inflammation in the lungs. These models have revealed that T helper (Th)1 and Th17 subsets promote a positive feedback loop that activates innate immune cells, confirming their role in emphysema pathogenesis. Results from genetic studies and immune-based discoveries have further provided strong evidence for autoimmunity induction in smokers with emphysema. These new findings offer a novel opportunity to explore the mechanisms underlying the inflammatory landscape in the COPD lung and offer insights for development of precision-based treatment to halt lung destruction.

[Treatment of chronic obstructive pulmonary disease and emphysema]

We summarized the available data on therapeutic, surgical and endoscopic treatment of chronic obstructive pulmonary disease and emphysema that may be used like a bridge to lung transplantation. Treatment of chronic obstructive pulmonary disease and emphysema is expensive. Certain limitations in lung transplantation make to create new methods of treatment of severe emphysema. However, one should be ready for possible complications and carefully select patients for certain treatment to avoid false negative results. Reducing costs or developing cheaper treatments is important for the future and availability of care. The risks and complications associated with surgical treatment of emphysema can make endoscopic surgery preferable for these patients, and this undoubtedly requires further research.