The answer's a bit complicated. First you must be evaluated to be approved for the placement of Zephyr valves. The process of having them placed requires two or three days in the hospital or more if you have a pneumothorax or pneumonia as a result of the placement. That's not expected, but it's not uncommon to have either of those things happen as a result of the placement. Talk with the center that does the procedure and they should be able to tell you how many of their procedures result in either one. Even if those things happen, it doesn't mean that the valves are not successful. Again, you can get results of the procedure from the center, so you should know how many people have been evaluated, how many chose to have the procedure, how many had pneumothoraxes or pneumonia, how many have the valves removed or coughed on out......all that kind of information should be available to you. Once you have all that information, you can decide whether the valves have good outcomes.