Medical Health Encyclopedia

Lung volume-reduction surgeries (LVRS) remove over 30% of severely diseased lung tissue and the remaining parts of the lung are joined together. Improvement in breathing after surgery appears to be largely due to the following factors:

• An improvement in the lung and chest wall's elastic recoil (its ability to spring back during breathing).
• Improvement in function of the muscles, such as the diaphragm, involved with breathing.

Outcomes. Two-year results of the largest study to date, called the National Emphysema Treatment Trial (NETT), indicate that patients who are good candidates for LVRS have better function and no higher risk for death than those on medical therapy. Mortality rates within 90 days of surgery are almost 8% compared to about 1% in patients on medical therapy. However, in spite of the early spike in deaths after surgery, there are no overall differences in long-term survival rates.

When the operation is successful, patients report significant improvement in walking distance, weight, and quality of life. Many patients can engage in active daily events, such as golf or climbing stairs, without oxygen. Even in carefully selected candidates, however, about 15% of patients derive little or no benefit from the procedure. (And about 4% become worse.) Furthermore, even in successful cases, the improvement is most notable within the first six months, after which the condition progresses again. Beyond two years, lung function deteriorates to the same level as it was before the procedure. It is not clear yet if surgery is cost effective over time compared to medical therapy.

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Possible Candidates. For now, the procedure is used only in people who have severe emphysema and not chronic bronchitis. And, it is applicable only to a minority of these patients. Appropriate candidates are those with the following characteristics:

• Under 75 years old.
• Having severe obstruction (FEV1 less than 40% but higher than 20% of expected value).
• Carbon monoxide diffusing capacity of more than 20% of expected value.
• Hyperinflated lungs (total lung capacity greater than 120% of the predicted value).
• Appropriate candidates who have deficiency of alpha 1-antitrypsin, even if they have disease in the lower lobe, may do well.