A guest article by Dr. Wei F. Chen. Dr. Chen is a plastic and reconstructive surgeon serving as a clinical professor and attending plastic surgeon at the Cleveland Clinic. He completed advanced microsurgical training at the world-renowned Chang Gung Memorial Hospital in Taiwan and is one of approximately eight plastic surgeons in the United States performing super-microsurgical reconstruction. He is a leading voice in the microsurgical treatment of lymphedema and takes a problem-solving approach to help patients find manageable ways to live symptom-free.
Lymphedema is anatomic swelling and bulkiness caused by lymphatic dysfunction or injury. Note that I say swelling and bulkiness because lymphedema is not just fluid. In fact, even the term “lymphedema” is a misnomer and that’s due to our earlier lack of understanding that lymphedema isn’t just fluid.
Lymphatic dysfunction could be acquired dysfunction or it could be congenital dysfunction. And also, even though we most commonly hear about arm and leg lymphedema, lymphedema can really affect just about any part of the body. There’s no organ that doesn’t have a lymphatic system, with the possible exception of the brain - although recently we found that’s not true. So any part of the body with lymphatic dysfunction will develop lymphedema - it could be arm, chest, breast, abdomen, genitalia, and so on and so forth.
Lymphedema starts out relatively benign and if you’re a patient of lymphedema, you know that lymphedema may progress and usually when it gets to the stage where you see a part affected where the normal anatomic contour is lost, usually by this point lymphedema is no longer just fluid. It’s no longer just swelling. There’s also a lot of abnormal fatty deposits - we’ll just call it lymphedema fat.
By this point, there’s a lot of lymphedema fat and since lymphedema is a chronic inflammatory condition, inflammation continues and it lays down scars both underneath the skin and on the skin. Typically, we don’t see it as obvious in the arm because the arm is more elevated compared to the leg, but in the leg, we can really see severe manifestations of this chronic inflammation on the skin.
Many call this elephantiasis because the skin is now severely compromised and quite fibrotic and at that point, the skin can spontaneously break down and a patient may develop spontaneous infection because the natural barrier to infection is compromised and not only that, but the immune system is locally compromised in the lymphedema-affected parts of the body. The leg is affected by lymphedema; the immune system doesn’t work well in the leg. Therefore, the patient will begin to see spontaneous infection, or infection from otherwise benign injury, such as a bug bite or a small cut.
Contrary to what you have been told, and contrary to what many medical textbooks are saying lymphedema is not and should not be a clinical diagnosis. We’re working as quickly and as hard as we can to change this, to educate medical professionals to change our medical textbooks to reflect this fact. Lymphedema should not be a clinical diagnosis.
What does it mean, “a clinical diagnosis”? A clinical diagnosis means we don’t perform any confirmatory tests. We look at you, the swollen arm or leg, and we listen to your story or history and then we say, “Hey, that sounds like, and looks like, lymphedema. So you have lymphedema.” So that’s what making a clinical diagnosis means. And if you look at modern medicine, we have a hard time coming up with other conditions we diagnose clinically. Common colds and flu, those are some. We don’t order clinical tests to diagnose someone having a flu, but lymphedema is a condition that patients live with, life-long, and need treatment life-long, or we perform surgery. We now have plenty of evidence to support this statement: Lymphedema should not be a clinical diagnosis.
For a clinical diagnosis, what people usually look for on clinical grounds is one, the Stemmer sign, and two, they measure circumference. In the Stemmer sign, or Kaposi-Stemmer sign, you can see the skin being pinched so that’s a negative Stemmer sign if the skin can be pinched. Inability to pinch the skin is considered a positive Stemmer sign.
In circumference measurement, the definition is: At any given level, if there is more than a 2-centimeter circumference differential or if the volume that’s measured is larger than 200 cc volume differential, it’s considered to be positive for lymphedema.
There are certain conditions that mimic lymphedema and cause limb edema:
- Venous insufficiency
- May-Thurner syndrome
- Heart failure
- Kidney disease
- Liver disease
- Deep vein thrombosis
- Occult fracture
- Hormonal disorder
- Rheumatoid arthritis
- Mass effect on subclavian vein (tumor)
So if the Stemmer sign and a tape measure are all you have in your toolbox and you’re trying to rule out or rule in all of these other conditions, I don’t think any clinician can confidently tell you that there’s 100% certainty that a patient doesn’t have these other conditions.
The diagnosis needs a confirmatory test. There are various confirmatory tests out there. Right now, I think the gold standard is indocyanine green lymphography (ICG). There are various machines that can interpret and perform ICG lymphography. All of them work. You don’t have to use any particular one of them.
This test is performed by injecting .1 cc of .25% ICG solution, a very trace amount, into a specific location. I’m using hands and feet as examples because arm and leg lymphedema are much more common than lymphedema affected other anatomic regions. After injection, it gets picked up by your lymphatic system rapidly and starts to move in the vessels. The scan allows us to evaluate the flow velocity of the obstruction and whether there is normal distribution of lymph vessels.
When there is early disease, when there’s injury, our body would try to repair the injury by sprouting or rerouting the lymph flow. So this rerouting is abnormal distribution because we know where these routes are supposed to be, so we know that your body has taken a detour. Your lymphatic system has taken a detour.
In the immediate scan, if the patient doesn’t follow the normal pattern, we know that something is wrong. We also need to do a delay scan in six hours. That’s because it takes time for the lymph to flow. In normal lymphatic systems, in general, in two to three minutes we would see ICG travel from the hand to the arm. But in a patient with lymphedema, the flow is sluggish and would take a longer time.
Also, there are three patterns - splash, stardust, and diffuse patterns - and it takes time for reflux to develop. Reflux patterns are abnormal patterns, these are the disease patterns. These patterns essentially diagnose lymphedema. A linear pattern is the normal pattern. A linear pattern is what we want to see.
So this is what happens when we do an injection. The ICG gets transported to deeper lymphatics and eventually to the collectors. If there’s an obstruction, then the lymph would take a detour and that’s the splash pattern. The reflux is more superficially, that’s seen as a stardust pattern, and eventually they move completely up to the dermal lymphatics, the intradermal lymphatics, and the subdermal lymphatics, that’s interpreted as a diffuse pattern.
I won’t go into clinical staging too deeply, but clinical staging is simply what we are seeing in terms of the severity. If there is swelling, if there is skin fibrosis, if there is presence of lipodystrophy, then we stage the patient clinically based on what we see clinically. The lymphographic staging is much more relevant to us when we are deciding how we’re going to treat this patient. For example, if you’re treating the patient with MLD, CDT, someone with a 90% occlusion of the lymphatic system at the axilla will respond poorly compared to someone who only has a 20% occlusion. So it’s very helpful and very relevant to know the severity of lymphatic injury.
Of course, there are other types of measurement - there’s the circumference measurement, the water displacement measurement, 3D scanning - which are all volume-based methods. So we perform these measurements also, but when we interpret these data we need to keep in mind that all volume-based measurements are significantly influenced by other factors such as weather activity, diet, the degree of compression, the presence or absence of solid disease.
Bioimpedance is also a helpful adjunct. Notice I’m saying it as an adjunct diagnostic test because contrary to what the manufacturers are saying, in our studies it hasn’t demonstrated sufficient sensitivity to be used as a diagnostic test. We find that a false negative is significant, however it’s a great tracking test to find out how the patients are doing longitudinally. Are the patients worsening or improving, responding to treatments?
Having performed all of the studies, now we have a confirmed diagnosis. Not only do we have a confirmed diagnosis, we know the severity of injury. So now we need to decide: Are we going to treat with surgery or therapy?
Both CDT and surgery are highly effective. So the way I look at it, instead of considering therapy as first-line treatment and surgery as second-line treatment, and only consider it when therapy fails, I disagree with that approach. I think therapy and surgery are two equally effective treatments and should be considered equally. They are just different treatments with different pros and cons, limitations, and advantages. And usually the advantage of one is the disadvantage of the other. For example, the advantage of therapy is that it’s completely noninvasive. Surgery is invasive. For therapy, if it doesn’t work out, patients usually are not worse off. If when the surgery fails, the patient is worse off, and there are risks associated with surgery, there are complications that can happen, so many things need to be taken into consideration when deciding should I get surgery or should I manage with lymphedema therapy.
We’re going to move on as if we decided to go ahead with surgery. Which procedure? These are all the surgeries that are currently available.
Microsurgery involves working on vessels or nerves smaller than 2 mm. In 1990, surgeons began to perform microsurgical lymph node transplants to treat lymphedema. Supermicrosurgery arrived in 2000 when Dr. Isao Koshima began treating lymphedema patients with supermicrosurgical lymphaticovenular anastomosis (LVA).
Where microsurgery ends, 0.8 mm, is where supermicrosurgery starts. Supermicrosurgery extends the limit of human surgery to structures as small as 0.1 mm, or 100 microns. To give some perspective, the blood vessel frequently used in heart bypass, left anterior descending coronary artery, averages 3.7 mm. At the larger end we have the maximally invasive debulking including the Charles procedure.
The key concept is that if the less-invasive procedure can get the job done, we prefer to offer the least invasive procedure that would provide a satisfactory treatment outcome. We like to offer the LVA whenever possible. The advantage of the LVA in addition to being a highly-effective, powerful procedure that is minimally invasive with minimal failure. We should also consider where we leave the patient if the surgery doesn’t work out. Surgery is not an exact science. Regardless of how good a surgeon you think you are, you can’t promise an outcome. You cannot say to a patient, “I never fail.” So we need to consider where we leave our patient if this surgery doesn’t work out.
The supermicro VA is to be distinguished from the lymphovenous bypass that was initially created in the 60s and 70s because these are different. The LVB created in the 60s and 70s was a micro or even macro lymphovenous connection. They’re usually done proximally and done using the deep lymphatics. Those back then, the surgeons observed inconsistent results, and now we know why. The key is to go small. The key is to go supermicrosurgical and by going small, we resolve the issues associated with the earlier procedure. In general, patients with a lot of linear patterns are excellent candidates for LVA procedures and when you see linear patterns on the ICG, that means the patient has functioning, healthy lymph vessels.
To perform the LVA procedure, we need to initially find the lymph vessels and we do this by performing an ICG mapping lymphography. This is to be distinguished from the diagnostic lymphography that we did for diagnosis. We need to hit all lymphosomes in order to visualize all available lymph vessels to target for LVA. We visualize the veins using a vein finder, then we can very precisely plan our incision. This looks like multiple tiny incisions that heal well and are usually quite inconspicuous.
There are different ways to connect the lymph vessels together.
- End-to-side x 2
Supermicrosurgeons debate about which configuration is the best, so people have strong opinions, and in my opinion they are all relevant. To debate one is better than the others, I think, is a bit pointless because even if you consider, let’s say, side-to-side is the best, you may not be able to perform a side-to-side given the situation. It’s important to train the surgeon to be versatile, to be proficient with all the techniques.
So before debating about which technique is the best, it’s more relevant to think about: Are you going to have a favorable pressure gradient? Because the LVA will only work if you have a lymphatic pressure that exceeds the venous pressure. Otherwise your LVA will fail.
For surgeons, if you want to start trying to help lymphedema patients, you can start training yourself at home. Particularly now, with COVID, you might want to start training at home. Get yourself some chicken from Costco or your local supermarket and you can start using these vessels in the chicken thigh to start practicing supermicrosurgery. Most vessels range from .1 to .6 mm and you can find .1 to .6 mm vessels in every single chicken thigh. Take some sutures and you can start practicing.
I encourage you to read “A novel supermicrosurgery training model: the chicken thigh.” This model, now known as the Chen Chicken Model, has been adopted at major microsurgery centers around the world to train their trainees. And you’ll say, “Hey I don’t have a fancy microscope or fancy supermicrosurgery instruments.” I don’t either. I practice at home using an eyebrow tweezer set that I got from Amazon for 15 bucks, and they’re actually quite good. And if you connect your phone to an external monitor, that’s a basic setup - but the basic setup is just to use a phone holder and you can practice micro and supermicrosurgery at home.
When the linear pattern is absent, LVA is still possible, however this is also when I start to consider lymph node transfer (VLNT) vs. lymph vessel transfer (VLVT). Based on our experience, we no longer perform lymph node transfer. VLVT looks a lot better, and is flat, so I think even if lymph node transfer works incredibly well, there’s still the issue of restoring form and function for the patient, which as a plastic surgeon we should always try to do.
It is true that we are capable of curing patients that are considered incurable. The key is to get treatment early. When the disease is severe, the patients don’t respond to surgery well. If the patients seek treatment early, there’s a lot we can do.