[Principles of lung volume reduction].
Lung volume reduction (LVR) is a new surgical approach designed to relieve shortness of breath and to improve exercise tolerance in patients with severe lung emphysema. Selection of patients for LVR is based on history, clinical investigation, chest X-ray studies, CT scan, lung perfusion scan, lung function testing, and blood gas analysis. Selection criteria are severe emphysema (FEV1 20-35% pred., TLC > 120% pred., RV > 250% pred.), dyspnea despite optimized medical therapy, abstinence from smoking, acceptable nutritional status and rehabilitation potential. Patients with a uniform pattern of lung destruction benefit far less than those with a more localised pattern (> 30% on chest X-ray or CT scan) with the remaining lung being quite normal and a reduced perfusion of only the damaged areas. Prior to the final decision for LVR, all patients are enrolled in a supervised rehabilitation programme of 4 weeks duration. Some patients benefit so much that LVR can be postponed. The surgical approach of choice is a median sternotomy for bilateral LVR when the upper lobes are the target areas and a bilateral thoracotomy if the lower lobes are mainly affected. When a bilateral procedure is contraindicated, a unilateral approach may be an option. It is not yet clear whether an approach by thoracoscopy allows adequate surgical removal of all affected areas and whether the morbidity is lower. Laser ablation is a further therapeutic option but is much less effective than the surgical resection. Reinforcement of sutures using bovine pericardium strips reduces the chance of a prolonged air leak but is expensive. The results from our institution in 57 patients 1 month after LVR surgery showed the following improvement in dyspnea was a consistent finding in 88% of patients, the 6-min walking distance increased on average by 150 m, the FEV1 by 0.3 1 for unilateral LVR and 0.5 1 for bilateral LVR. The mean PaO2 in ambient air increased 6 mmHg after unilateral and 8 mmHg after bilateral LVR. There was also a significant improvement in respiratory muscle function and a reduction in respiratory drive. A significant improvement in quality of life was documented in 83% of the patients. Major hospital complications are prolonged air leak, pneumonia, and myocardial failure. Three cases of a delayed pneumothorax were observed. Early hospital mortality (< 30 days) was 1.7% and 90 days mortality 3.4%. Few follow-up data are available beyond 1 year, and the long-term benefit of LVR surgery therefore remains to be defined.