This week’s blog post will focus on a study by a group of researchers from Switzerland. It’s entitled, Indocyanine green lymphography as a novel tool to assess lymphatics in patients with lipedema, and was published in the peer-reviewed periodical Microvascular Research in December 2021.
This study aimed to describe the anatomy of superficial lymphatics and how they function in women with lipedema using indocyanine green (ICG) lymphography. They were also interested in the association between lymphatic functioning and the patient’s clinical characteristics and body composition. The authors stated there is a need for an objective diagnostic tool that can clearly differentiate between lipedema and lymphedema and ICG maybe this tool.
Studying Lymphatics in Lipedema
Lymphoscintigraphy is most often used to study lymphatics in lipedema. The authors note that although this technique is reliable, it has several disadvantages including very low image resolution, radiation exposure, high cost, long examination time, and discomfort for the patient. ICG lymphography, on the other hand, is a relatively simple technique. It gives an accurate picture of the lymphatics in real time, does not use radiation, and is less painful for the patient. ICG lymphography is limited to visualizing the superficial lymphatics, however, as it can only show lymphatics up to 2 cm in depth.
Who were the participants?
This study included 45 women with a clinical diagnosis of lipedema as their subjects. The average age was 39, and 40% were classified as obese by BMI. Regarding symptoms, 100% of the participants had pain, 91% bruised easily, and 69% complained of heaviness in their legs. The average duration of their symptoms was 16 years. The largest groups of participants, with 49% each, had type III lipedema (excessive fat tissue from the waist to ankles) and were stage II lipedema, which the authors describe as the skin being “indented over palpable pearl-sized nodules.” 58% of the participants had been regularly using compression therapy, such as compression garments.
What were the measurements/assessments used?
The participants of this study were evaluated with the following tools:
ICG lymphography to visualize the real-time anatomy and functioning of the lymphatics. The dye was injected into the top of the foot with the total distance traveled in 10 and 25 minutes measured.
Dual-energy X-ray absorptiometry (DXA) scan for body composition including fat and muscle. The results were examined along with the ICG lymphography to see if there was any association between lymphatic functioning, symptoms, and body composition.
What did they find?
Now let’s look at the notable results of this study.
Typically, the dye will reach the groin within 25 minutes, but in this study, this wasn’t accomplished in 25 (56%) of the women. After all of these participants were then provided with manual lymphatic drainage, the dye reached the groin successfully. As a side note, I would say that this certainly suggests the utility of manual lymph drainage for lipedema patients. While age, BMI, and use of compression garments were similar for those who drained within 25 minutes and those who didn’t, the slow drainers had a significantly longer duration of lipedema symptoms and a higher percent body fat. There was also no significant difference between slow and normal drainers with regard to lipedema stage or type.
The structure of the lymphatics in participants was mostly linear, as healthy lymphatic vessels should appear. Previous imaging studies have shown anatomical changes to lymphatic vessels in lipedema where there is a circuitous and tortuous pathway instead of a nice straight path. In this study, only one woman showed rerouting of fluid and this was in an area of previous trauma at her knee. None of the participants showed what is called dermal backflow, which is often a sign of lymphedema.
What were their conclusions?
The authors conclude that although there were minimal signs of anatomical or functional impairment of the lymphatics in the participants in this study, women with lipedema may still have slowed lymphatic drainage. This seems to be correlated with the duration of the disorder.
This study adds to our understanding of the anatomy and function of the lymphatic system in lipedema, making it important for women with lipedema. ICG lymphography may be an important tool to properly determine if there’s lymphatic impairment. It also emphasizes the need for early and accurate diagnosis and treatment to hopefully avoid impairments that seem more likely to appear the longer the lipedema symptoms are present.
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