A couple of days ago, in a different place, I answered a request for info about coil implants. I thought my answer might be relevant here, so here it is.
This could be a fairly long answer so please bear with me.
My own position is that I had valves to my right lung very successfully in February 2012. I give presentations at medical seminars to give a patients perspective. I am not medically trained.
Yesterday (Tuesday, 13/05/2014) I was at a seminar in Cardiff about the Modern Management of Emphysema. Part of that seminar discussed surgical and associated methods of intervention, and coils were discussed as part of that. Valves and coils are used as alternatives for Lung Volume Reduction from surgical methods where diseased parts of lungs are cut from the chest. From where we were several years ago to the present, many advances have been made, particularly with regard to the use of valves and coils, and the management of patients after these devices are fitted. Valves received early acceptance, because they are easy to implant and have a much lower impact on the patient, and importantly, should they prove to be causing problems, they can easily be taken out. These valves are little one-way valves that are set to only allow air to pass out of the targeted area of the lung. This has the effect of sucking that part shut, thereby reducing the volume of the lung and allowing that rest of the lung to operate better. The down side of valves is that they are suitable only for a relatively smaller number of patients. This is because they work well only if the divisions between the different lobes of the lung are intact. (These divisions are called ‘fissures’, and are substantial features inside the lung that can be seen on X-ray or CT scan images.) See what I wrote about Colateral Ventilation as an answer to a question within this article,
Using coils is one way to avoid the problems associated with colateral ventilation, because their action is purely mechanical. They are made from a medical alloy called nitinol (an alloy of nickel and titanium that our bodies find acceptable, and do not reject). Nitinol has a very useful property in that it is a memory spring. It will always try to return to its set shape. A number (usually about 10) are placed into targeted areas in the lung using a bronchoscope (tube with camera down the throat). They go in straight, and return to their ‘memory’ shape over a period of several days. This makes that part of the lung ‘scrunch’ up.Collectively, they close down a section of lung and reduce the volume of the lung. Advantages are mainly that colateral ventilation is not an issue. Disadvantages. Some patients have had some discomfort as the coils take up their natural or memory shape. The areas closed off lose any ventilation, so that natural secretions as well as mucus cannot drain from that part easily. Coils require a minimum density of tissue to get hold of, so if you have large cavities or ‘bullae’, then they are not suitable. Internal tearing of the tissues within the lung is also a small, but possible risk. Therefore infection is an issue that needs consideration and urgent treatment if it occurs. If a problem does present itself, extraction of only a few coils may be possible. This procedure is not considered reversible.
A couple of short videos for you to see. The first shows how valves are fitted, and the second one explains coils.
I hope this helps. If you need more info, ask.