Lymphatic occlusion pressure is around 80mmHg. That is how we get flow from lymphatic to vein #Lymphedema #Microsurgery #ESL 2014 Genoa
Success of #microsurgery for #lymphoedema depends on number of anastomoses - need multiple surgeons like at Oxford Lymphoedema Practice
Microsurgery seems to be the best way to prevent #Lymphedema Need to start #screening after #breastcancer and other #cancer treatment
How does microsurgery work is a very important question! In order to answer it, we need to know about the function of the lymphatic system. Each day, around 3 litres of fluid is lost from our blood stream by being filtered out in our capillaries. These are the tiny blood vessels that are found in every part of our body. The fluid has an important function – to deliver oxygen and nutrients to every cell in our body, quite simply it keeps us alive.
However, we only have around 5 litres of blood in our body, so we can’t simply lose this 3 litres per day into our tissues, we need a way of returning it to the bloodstream. This is what the lymphatic system does. It absorbs this fluid, and actively pumps it back up your arm or leg, through bigger and bigger channels, until it reaches a vein in your neck, where it releases the fluid back into the bloodstream.
I am sure everyone will remember from schooldays, that for fluid to flow in a particular direction, there must be a pressure gradient. Think of the weather maps you see on TV, the wind always blows from an area of high pressure, to an area of low pressure. It is the same with lymphatic fluid flowing into the blood – the normal lymphatic pressure is higher than the normal venous pressure, allowing the fluid to be returned to the bloodstream.
In secondary lymphoedema, there is a problem with this system, usually caused by surgery or radiotherapy to the lymph glands. This causes a blockage in the system, and increases the lymphatic pressure further. Lymph fluid tries to find a different route out of the limb, but this is not so efficient, and fluid therefore builds up. I find it helpful to think of cars travelling on a motorway. If there is a crash, and the motorway is closed, cars start to back up, and then they will start to leave the motorway and travel on the A roads and B roads to reach their destination. This journey is not as efficient as if the motorway was still open.
However, when thinking about microsurgery, we must keep in mind what the destination is – the blood stream. What if we could build a bypass around the blocked motorway, that lead straight to our destination? Wouldn’t that be fantastic? Well, that is what microsurgery for lymphoedema achieves. We perform LVA (lymphaticovenular anastomosis) that joins the lymphatics just under the skin to tiny veins found near the lymphatics, returning the fluid to the blood stream without it having to go past the blockage.
Jean-Paul Belgrado from Brussels, demonstrated with a transparent tourniquet and ICG lymphography that the occlusion pressure of lymphatics is around 80mmHg – this is much higher than venous pressure at around 10mmHg.
It was also emphasized in this session that for microsurgery to be effective, multiple bypasses should be completed. This makes sense – the more bypasses you open up, the better the relief of the congestion. It is also likely that some of the bypasses will fail for technical reasons. If you only have a few bypasses and some of them fail, this could be critical to the outcome of surgery. However, if you have a lot of bypasses and some of them fail, there might well be more left open to do their important job. For this reason, I would always recommend choosing a team of experienced surgeons for your microsurgery operation – more surgeons equals more bypasses in the same amount of time, critical to success. This is one of the reasons single surgeons can struggle to make microsurgery work in the treatment of lymphoedema.
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