What is the Lymphatic System?
As part of the immune system, the lymphatic system helps the body activate a specific immune response against viruses and bacteria. It retains fluid homeostasis in all different compartments of the body. It is made by channels called lymphatic vessels. These collect lymph from all over the body and deliver lymph to the regional lymph nodes or thoracic ducts and then back to the cardiovascular system.
What Causes Lymphedema?
Lymphedema occurs when your lymphatic system is unable to properly drain lymph fluid. In addition to primary (congenital) lymphedema, secondary lymphedema is more common and is usually caused by diseases or other treatments. Secondary lymphedema is a common complication after lymph node removal, typically occurring following cancer surgery and radiation therapy. Additionally, lymphedema can result from lymph node damage caused by infections. When the lymphatic system becomes blocked, lymph fluid cannot drain efficiently, leading to fluid buildup in the arms and legs.
What is Lymph fluid?
Lymph is a colorless protein-rich fluid that physiologically collects waste products and pathogens. It is present in tissue and transported through the lymphatic system to regional lymph-nodes. The venous flow carries 90% of arterial blood back to the heart and the remaining 10% becomes lymph fluid in the interstitial. Peripheral lymph nodes drain approximately 4-8 liters of lymph fluid per day. The lymphocytes (infection-fighting cells) that reside in the lymph nodes activate a specific immune response against infection.
What are Lymph Nodes?
Lymph nodes are bean-shaped organs of the lymphatic system that are distributed widely throughout the body. They are composed by lymphoid tissue enclosed by a capsule of connective tissue. Lymph nodes are major sites of B cells, T cells, and other immune cells. They serve as filters for the blood and provide specialized tissues where foreign antigens and cancer cells can be trapped and exposed to cells of the immune system for destruction. They are typically found concentrated near junctions of the major lymphatic vessels and most prominently found in the neck, groin, and armpits.
Why is the lymphatic system important?
The lymphatic system has two important roles: activating the immune response against antigens and transporting lymph fluid. Both functions are important to preserve body homeostasis. When the lymphatic system is compromised by cancer, infections, surgery, trauma, or congenital issues, the affected part of the body is prone to swelling (lymphedema) and recurrent infection due to the faulty surveillance mechanism. The functions of the lymphatic circulation include prevention and resolution of edema, maintenance of interstitial fluid homeostasis, immune trafficking (the regulated transit of antigen-presenting cells to the lymphoid organs), and lipid absorption from the gastrointestinal tract.
Recipient Site of Vascularized Lymph Notes Transfer
I.Wrist, dorsal or volar
II. Elbow
III. Axilla
IV. Groin
V. Posterior proximal leg
VI. Ankle, anterior or medial
Pathophysiology of
Lymphedema
i. Lymph accumulation
ii. Inflamation
iii. Infection
iv. Fat proliferation
v. Fibrosis
Donor Vascularized
Lymph Notes
1. Submental
2. Supraclavicular
3. Thoracic
4. Groin
5. Omentum
6. Mesenteric
此圖右側肢體正常，左側為上肢及下肢淋巴水腫。
可使用的治療方法如：淋巴管靜脈吻合術或顯微淋巴結皮瓣移植。
Lymphatic Circulation Flowchart
Explanation of Physiological and Non-Physiological Surgical Approaches for Treating the Lymphatic System
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