Collateral Ventilation Explained Simply!!

Below is an explanation of Collateral Ventilation, this came up on one of my visits to Jimmy’s. The surgeon mentioned that I would not be able to have endobronchial valves if the lobes of my lungs affected had ‘collateral ventilation’. I went home and straight away tried to find an easy explanation for it. I am now sharing my knowledge with you –

Collateral Ventilation Explained

In the lungs of a normal, healthy person, there is one single route inwards and out again for each of the alveoli (alveoli are the tiny cavities at the end of the airways where the gas exchange with the blood happens). Think in terms of a bunch of grapes. Alveoli are the grapes, the airways are the stalks.

When the lungs get damaged, whether through disease or pollution or irritation, if the membrane suffers extensive damage, then some of that membrane is replaced, as part of the healing process, with scar tissue. If there are repeated episodes of disease, or sustained exposure to pollution or other causes of irritation, then the amount of scarring can become significant.

Scar tissue is not as elastic as the original membrane. It also does not permit gasimages (1) exchange. As our lungs expand and contract, if the sites where scarring has occurred have become a significant size, then some tearing can happen. This tearing is minute, and is no cause for concern in terms of day to day wear and tear. It is the long term combined effect over years that is the problem. This is where we now jump to, several year down the line. Imagine that two adjacent alveoli have a lot of scarring, and another inflaming infection takes hold, and one particular breath is deeper and heavier than normal, and it causes a tear that goes through the tissue between the alveoli. You now have a hole that will not close. The tissue will heal, but leaves an enlarged cavity because that requires less stretching than the original formation. For the bunch of grapes, two grapes have been replaced by one damson fed by two stalks. After several more years, a number of damsons have formed, and some of those have merged into much larger plums. This is now advanced Emphysema, with some large cavities (called bullae), and we are at the point where medical intervention is required. This is what has happened to me on my upper left lobe I have just got one large bullae. It is filled with too much air, imagine it as been blown up like a balloon but there is no way out for the air because the valve letting air in and pushing air out is no longer working. Air gets trapped taking up vital lung space so any good parts of your lung are compromised by this shortage of space taken up by this massive balloon.  One of the things that has to be considered to determine which operation is best to go for is how this damage presents itself.

The structure of the lungs is that they are divided into zones called lobes, three in theDiagram of lungs right, and two in the left. Thinking in terms of the bunches of grapes, consider that each lobe is home to one complete bunch whose only contact normally is through the main stem (the main airway). If the damage within the lungs is confined within the individual bunches, in other words, does not cross the boundaries between the lobes, then there is no collateral ventilation. Collateral ventilation occurs when the the tissue damage permits the passage of air between the lobes through holes between the lobes.

As the damage progresses, as the cavities form, so the internal support structure of the lungs gets reduced. This allows the lungs to become longer and they over inflate because of the loss of elasticity. They sit on the diaphragm, the bottom lobe of each lung gets compressed and generally cannot continue to work properly. The diaphragm now has to lift this extra weight with each breath taken. Through a day, that adds up to a lot of extra hard work. Taken with the loss of alveoli, and the presence of frequent infections etc, the lungs are now operating at maybe as low as 15% of their full capability when in good condition. The patient is permanently fatigued and needs lots of medication to keep the airways open. Often oxygen is needed. At this point, the consultant decides that surgical intervention is required. The first choice at the moment for most consultants is to use pulmonary valves. They are easy to fit, they allow the blocked off part of the lung to continue to pass CO2 and the lungs natural secretions out. Most importantly, they are reversible (if need be, they can be removed easily). The biggest deciding factor in choice for or against valves is whether or not there is collateral ventilation. If there is none, or is very minor, then valves could be considered. If there is collateral ventilation, then the usual decision is to go for lung reduction surgery. I had to have a lung ventilation scan  (see link for details of this), it was found from the scan that the divisions in my lobes are not ok and have scar tissue so I am not suitable for the valves in that area, it will collapse too much of my lungs.  This is all the damaged caused from Chronic Bronchitis which I have had through smoking. Dr Kemp in London explained that I have emphysema all over my lungs but it is pretty bad at the top of the right lung  so that is where they will start by cutting it off. He said he might consider valves for the other side.

As you can see, at the stage where there needs to be a choice made, the presence or not of collateral ventilation is important. Links to some videos that may help follow:……






The day before the appointment I went on Google Earth to familiarise myself of its location in Leeds and I am glad I did, it is a massive hospital. I did a few print outs and went through what I wanted to ask the specialist surgeon when I saw him. And said all my prayers for help that it would be a good outcome.

I had a poor nights sleep wondering and worrying what they were going to say to me at Jimmys. My own specialist is always talking doom and gloom and so is my GP, telling me how bad my X Rays are and breathing tests etc. However, I am wondering now if my specialist at Huddersfield saw a better picture when she saw my scan recently, because, after pulling me in for an extra appointment last month, she said that she wanted a chat in general about going ahead with the valves and that I really didn’t need to have the operation done. She said, ‘people live for years and years like you are’, (exactly I thought, I don’t want to live like this for years and years), this was a bit of an about turn to how she had been talking to me before! (sorry if I have previously mentioned this in another post). Well back to Leeds.

The journey to the hospital was very easy for me as my Daughter drove, bless her it was only the 2nd time she had driven on theimages (10) motorway and the first time she had driven in Leeds. Anyone who has driven in Leeds knows that the ring road is a nightmare and the first time I went to Leeds years ago I managed to do a few circuits of that before I reached my destination. I am not good with directions. But, now we have our built in Sat Nav I thought it would be easier for her. But noooo it wasn’t! Poor lass she only got stuck on the ring once on our way home and got really cross with the Sat Nav. When we arrived at the Hospital I was so glad that I have familiarised myself with its lay out because we would never have found our department as it was right around the back of the building. It was great because my daughter dropped me off outside the doors so that I didn’t have a lot of walking to do and she then parked the car up in the multistory, it saved me so much hassle.

The department that I was seen in was Surgical Outpatients and was located on the ground floor so it was very easy to find and they were running quite late so we had to wait for about an  hour to be seen.`1

When I saw the consultant surgeon at Jimmys he drew a picture of my lungs and showed me the bits that were not working and it wasn’t as much as I had previously been told! You can’t believe the relief that I felt I could have cried. It is actually just the very top parts of both sides the right side being worse than the left. He explained that the parts not working had developed multiple  bullae, which is –

an air pocket in the lung that is greater than one centimeter in diameter (across). Bullae tend to occur as a result of lung tissue destruction and diseases such as emphysema. Their presence in the lung takes up space, causes pressure and blocks your breathing.

I told the consultant surgeon that it felt as though I had a blockage in the top of my lungs when I tried to breath. I said it’s not like I am out of breath, I just can’t catch my breath and its a horrible feeling you panic. Its like being water boarded. He showed me the back of my lungs on the scan and said they were in fairly good condition. SO what is happening I would like to know and he then explained what was going on!

He listened to my lungs and said that a lot of good air was being taken in but very little pushed out. my lungs were running out of space because of these two top bits blowing up like a balloon and there is another couple of bits lower down but not that bad. So if everything goes to plan the situation can be corrected. I won’t get better overnight it will take time but there is a solution! He gave me two alternatives –

  1. Surgery – they can cut the top bits off my lungs so the other larger part can function correctly (don’t know about this)
  2. Insert valves that will empty the air out and not let any back in, in time these deflated balloons with shrink allowing my good lung to function, no surgery would be involved with this. However, it all relies on funding for this as its a very expensive process. It sounds better though, I don’t fancy being put under the knife but I would be open to suggestions from anyone who reads this post.

Before any decisions are taken I have to have a nuclear scan to test the actual function of my lungs they are not relying on my lung function test I had at Huddersfield, and I don’t blame them I am terrible at blowing into those things. To get a more accurate picture of my lung function the surgeon said the best way is with a nuclear scan and I will have it done within the next few weeks.

He said that they  tend not to operate until the good weather comes in so I shall be having my operation in the summer months, I would imagine some time after March!

I know a lot of people who will read this will think why is she so happy about having all this, bullae, operations and everything, what makes a person so happy to know all this!  Well the reason is, I thought I might be so bad that I wouldn’t be able to have any help and I would finish my life off like this, which is not a great quality of life, being out of breath every day. Its like you have to run a marathon every day of the week it makes you so tired.

Anyone who has severe COPD will understand how I am feeling, I have stopped smoking, done everything you are supposed to do, changed my diet (could do better with that) but, I have done as much as I can to help myself and had run out of options. I didn’t understand what was happening to me why was I getting worse when I had done all I had. Well it was them pesky bullae blowing up and stealing my breath, now I understand what is happening! He more or less finished the interview by saying that I had found them through my own volition  and they would do what they could to help me.

The Nuclear Scan (link to piece on the scan)

I will be having my scan during the next few weeks and I think the above video is quite good. It explains the process quite well and I will be glad when its over. Another Hurdle will then be over. What was it like?