Measuring Collateral Ventilation for Bronchoscopic Volume Reduction

Dear Dr. Mahler: I read your post on December 11, 2015, about the need to measure collateral ventilation to know who might benefit from placing valves into the airways to collapse parts of emphysema lung. My pulmonary doctor has mentioned a study/program in Boston that I am considering.  I have “advanced emphysema” and am limited in doing anything more than daily activities.  I struggle with yard work, raking, and even walking our dog. I would like to know more about how is collateral ventilation measured?  Is this complicated? Many thanks. Albert in Saco, ME Dear Albert: Your question is quite important. Studies have shown that the valves are effective in collapsing lung that is not working only if there is no collateral ventilation present. Please review information about collateral ventilation on my December 11 post. To answer your question, there are several ways to measure whether someone has collateral ventilation. If a valve is placed in a lobe in the lung with collateral ventilation, the lobe will not collapse and therefore will not help you breathe easier. In the article by Kloosters and colleagues published in the New England Journal of Medicine, the authors used a method called the Chartis System. This system was developed by Pulmonx, a company who makes the Zephyr valves used in the study. Here is a brief summary. I will try to make this complicated process as simple as possible. First, you are given medication to make you sleepy and temporarily forgetful
Bronchoscopy used to measure collateral ventilation

Diagram of scope passed thru mouth into the lungs (called bronchoscopy)

(called conscious sedation). Then, a bronchoscope is passed through your nose or mouth into the breathing tubes (airways). A plastic tube is then passed through the scope, and a balloon at the end of the plastic tube is inflated to block flow or air to the “target’ lobe. The tip of the plastic tube extends beyond the balloon and can measure any air flow to determine whether collateral ventilation is present or not (see figure below).
System used to measure collateral ventilation

Scope on right with plastic tube and balloon inflated that blocks flow of air into the lobe.

You can find more information on the website:    https://pulmonx.com/ous/products/chartis-system/ Placement of valves into emphysema lobes has been approved in most counties in western Europe and is a common treatment for advanced emphysema in Europe. However, in the US, the Food and Drug Administration has not approved this procedure at the present time. So, you will need to go to a medical center doing a study on placement of valves for emphysema. Beth Isreal-Deaconess Medical Center in Boston is the nearest center to Saco, Maine, doing this research procedure. Certainly, your pulmonary physician can refer you for evaluation if you are interested. Best wishes, Donald A. Mahler, M.D.

Donald A. Mahler, M.D. is Emeritus Professor of Medicine at Geisel School of Medicine at Dartmouth in Hanover, New Hampshire. He works as a pulmonary physician at Valley Regional Hospital in Claremont, NH, where he is Director of Respiratory Services.