Their emphysema must be severe enough to warrant the risk of surgery, but not so severe as to excessively increase those risks. They must be free of other medical illnesses which would increase surgical risk or reduce possible benefit. They must have a support system to help with their post-operative recovery, which can be prolonged. Reported improvements in lung function or exercise tolerance range quite widely. Some patients fail to improve or may even worsen.
Any improvement obtained is temporary.
The deterioration in FEV 1 following LVRS is rather rapid, compared to historical control patients with COPD who do not smoke. Little long-term data is available yet, but some patients have returned to baseline within one year. Attempts to pre-operatively identify those patients who are likely to die, fail to benefit, or fail to sustain benefit have so far been inconclusive. A multicenter randomized trial comparing medical therapy together with lung volume reduction surgery to medical therapy alone is currently in progress. This study, the National Emphysema Treatment Trial, is underway at 17 centers around the country.