This chapter will address lymphedema management and the evaluation and treatment of patients fitting the model of preferred Practice Pattern 6H: Impaired Circulation and Anthropometric Dimensions Associated with Lymphatic System Disorders.1 Knowledge of this practice pattern will enable therapists to effectively evaluate, differentiate between diagnoses, and provide appropriate intervention for patients with lymphatic system dysfunction.
This chapter provides a review of the anatomy and physiology of the lymphatic system, discussions of the stages of lymphedema, and evidence to refute and support current methods of treatment for lymphatic system disorders. It is imperative to have a basic understanding of the lymphatic system in order to deliver appropriate interventions.
In addition to immune defense, the purpose of the lymphatic system is to drain substances that the venous blood circulation is unable to reabsorb. The lymphatic system functions like a “sweeper” to clear the interstitial space (also known as the third space or tissue space) of excess fluids, cellular debris, long-chain fatty acids (found only in the intestines), and protein molecules, otherwise known as the lymphatic loads.2 There is a continual shift of fluids within the body at the microcirculatory level of the blood capillaries. It is the responsibility of the lymphatic system to facilitate the fluid movement from the tissues back into the bloodstream—to maintain a state of homeostasis. Under normal physiological conditions, this fluid management will “maintain blood volume and eliminate chemical imbalances in the interstitial fluid.”2–5
Lymphatic vessels, lymph nodes, and other lymphoid organs and tissues comprise the lymphatic system. The lymph system represents an accessory route by which fluid can move from the tissue spaces into the blood. The lymph system protects the body by removing foreign material from the lymph fluid; that is, it filters lymph fluid and constantly surveys the body for the presence of foreign material. Lymph tissues contain macrophages, lymphocytes (T cells or B cells), plasma cells that produce antibodies, and reticular cells that form the lymphoid tissue stroma.3,4
The main organs of the lymph system are the lymph nodes, spleen, thymus, and tonsils. Lymph nodes appear in clusters or chains intermittently along lymphatic vessels, and their primary responsibility is to filter the lymph fluid. There are approximately 600 to 700 lymph nodes in an average-size person. A larger number of lymph nodes are strategically located in the cervical region (100–200) and in the mesentery (200). A fibrous capsule surrounds each lymph node that encloses the cortex and the medulla. The cortex of the lymph node contains mostly lymphocytes, which act in the immune response. The medulla contains macrophages, which engulf and destroy viruses, bacteria, and other foreign debris. Lymph moves quickly into the lymph node via afferent lymphatic vessels from the capsular side of the node and proceeds slowly through the chambered areas of the medulla. Lymph fluid leaves the nodes via the efferent lymphatic vessels from the hilus ...