Endobronchial Valves Significantly Improve Emphysema

The International Endobronchial Valve for Emphysema PalliatioN Trial (VENT) was conducted between December 2004 and April 2006, involving 321 patients with severe heterogeneous emphysema in 31 centers across the United States and Europe. The patients were randomly assigned to the treatment group or a control group in a 2:1 ratio. Primary study endpoints were forced expiratory volume in 1 second [FEV1] and the 6-minute walk test, evaluated at 6 months after treatment.

The study findings showed that among the 220 treated patients who received valve placements, FEV1 had improved by 5.8%, whereas for the 101 controls, FEV1 declined by 0.6%. For the other primary study endpoint, the 6-minute walk test, treated patients improved their distance by 1.7% (about 15 meters) after 6 months, whereas the controls' distance declined by 4.0%. Most secondary endpoints, including quality-of-life scales, also significantly improved. The study results were presented at the 17th Annual Congress of the European Respiratory Society, held during September 2007 in Stockholm (Sweden).

"The underlying logic behind both valve placements and surgical resection is to ‘shrink the footballs' in the chest that do nothing but take up space,” said principal investigator Frank Sciurba, M.D., of the University of Pittsburgh Medical Center (PA, USA). "Inflated, diseased lung saps air from functioning lung and pushes the lungs down too far into the abdomen, where they impair normal mechanical function of the diaphragm.”

The endobronchial valve is designed to block airflow to a diseased region of an emphysematous lung, thereby conferring the benefits of lung volume reduction surgery (LVRS) without the risks of major surgery. The one-way valve allows gas to vent from the isolated lung section during exhalation but prevents air from refilling the area during inhalation. The valve also allows mucus to be expelled, which reduces the chance of infection. Most patients require three valves to be implanted to isolate their most damaged lung section.


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University of Pittsburgh Medical Center