Anatomy of the Lymphatics

1) The initial lymphatics are endothelial vessels converging to form collecting lymphatics. The linings of the initial lymphatics have a high endothelial layer but no pericytes or smooth muscle media. They form a 3 dimensional plexus – like patterns within the connective tissue. The walls of these initial lymphatics have a one-way valve system. The valves prevent the reversal of the flow pattern. They are anchored by filaments to the connective tissues. The molecular structure of the vessels is similar to the anchoring filaments. The initial lymphatics collect interstitial fluid, proteins, lipids, colloids and cells. They feed into the contractile lymphatics, which has smooth muscle media. The unidirectional flow pattern happens here at this level. Since they have no smooth muscle media they depend on neighboring tissue structures for expansion and compression. This occurs by rhythmic deformation in 4 easy ways- skeletal muscle movements, arterial pulse and vasomotion, intestinal peristalsis and skin massage.


2) Collecting Lymphatics – The collectors have a sympathetic motor innervation. The values are bicuspid. The outer wall of the collectors is supplied by a rich network of blood vessels and myelinated nerve fibers. Collectors walls have 3 layers. Tunica intima, tunica media, tunica adventitia. In the tunica intima the endothelial cells have a cuboid/rhomboid shapes. There is a nuclear bulge in the lumen. In the cytoplasm there are vesicles, ribosomes and cytoplasmic filaments. Mitochondris Gogi app, centrioles and multivesicular bodies are in the cytocentrum. In the tunica media there are long smooth fusiform muscles cells that are essential to its function. Between the endothelium and the tunica media is an elastic membrane.


Open junctions are not present in the collectors. The adventitial layer has fibroblasts, collagen fibers and fiber bundles loosely arranged and parallel to the axis of the vessel. The outer wall of the collectors is supplied by a rich network of blood vessels and myelinated nerve fibers.


3) Lymphangions – In the collecting lympatics each vascular segment between 2 sets of valves represents the morphofunctional unit called a lymphangion. The contractions of smooth muscles of the lymphangion play a decisive role in lymph transport. It resembles small hearts.


4) Lymph nodes – They are peripheral and secondary lymph organs, along with the spleen, tonsils and lymphatic tissues of the mucous membranes. The nodes are present in groups or chains along the blood vessels. Their number size and form vary. The lymph node is encapsulated by an outer layer of collagen fibers. Blood vessels and efferent lymph vessels leave via the hilum. The internal framework is composed of trabeculae. Some trabeculae carry vessels from the capsule to the hilum. Between trabeculae there are reticular cells and reticular fibers. The space is filled with lymphatic tissue. The lymph traverses the nodes via the sinus system. The afferent collectors penetrate in the node through the capsule to peripheral sinus. Lymph runs from the peripheral sinus to the medullar sinus. At the hilum the medullar and peripheral sinuses combine to form a terminal sinus form the efferent lymph vessels originate.


Lymph node function: The lymph nodes are biological filtering stations. The phagocytic action of the macrophages cleanses the system of bacteria, cell debris, antigens and corpuscular elements. The lymph nodes produce lymphocytes. The lymph nodes regulate the protein content of the lymph, so that is the same as the intercellular fluid. The most significant changes in the lymph fluid occur there. They are like fluid exchange chambers where the protein concentration is established so there is equilibrium as Starlings law suggests.


Lymphatic pathways of UE-Lower arm to elbow – 4 primary-anterio-lateral and anterio-medial, posterio-lateral and posterior-medial.


4 secondary-bicepital, anterio-medial basilic, anterio-lateral cephalic and posterior triceptial Caplans pathway.


The cephalic pathway has 3 routes – to cephalic vein to nodes in axilla, across clavicle to C/S transverse nodes, to the clavicopecotoral group of the cephalic lymph nodes.


Lymphatic pathways of the LE – The superficial bundle: The ventromedial bundle – greater saphenous vein, the dorso-meidal bundle lesser saphenous vein.


The deep bundles: the anterior tibialis bundle, the posterior tibialis bundle.


(Lymph nodes of the LE. There are Superfical nodes there are upper and lower groups and Deep inguinal nodes that follow the femoral vein.)


Lymphedema is a collection of protein rich fluid caused by reduced transport capacity with insufficient tissue proteolytic activity in the face of a normal lymphatic load as defined by Foldi. It is an accumulation of water, proteins and in increase in cellular and ground matrix.


Unilateral Chronic Lymphedema clinical findings:


1) Pain is not constant


2) Positive stemmer sign


3) Fibrosis – development of fatty tissue


4) Papillomatosis


Lipedema: Edema that is caused by abnormal adipose deposits in the subcutaneous regions. It is usually bilateral in nature and affects mostly women. There is often a family history. There is no pitting signs, often associated with obesity and “orange peel ” at visual inspection and painful with pressure. Usually located between the pelvis and the ankle with sparing of the feet. Often it occurs 1-2 years after puberty.


Research for MLD-Leduc Method: The research method included using a Lymphoscintigraphy and a nanocolliod with TC 99 and a gamma camera to record activity. The call up maneuver enhanced the flow when applied proximally to the lymphedema. The reabsorption maneuver increased significantly the colloidial protein reabsorption. The call up maneuver will not enhance the flow if lymph nodes are in between the lymphatic site and the treated area. In 8/13 people a new pathway was established with MLD who underwent a min of 19 MLD RX’s. The study showed there is no contraindications in using MLD in people with heart failure or lower limb edema. It was shown that with the use of lymphoflouroscopy an increase in lymph flow was seen with the MLD and superficial mapping of the pathway could be seen as a result also. It is evident that MLD is a significant intervention for those with lymphedema and can be used alone as a source of treatment with good results.


Research for MCB-Leduc Method: They researched whether MCB with muscular contractions would effectively decrease lymphedema. They used a pressure transducer at the skin/bandage region to record the results and a hand held manometer to do the repeated contractions with. Then they were able to track the labeled colloids at the axilla and it was statistically significant. An increase in activity occurred at 6 min and 40 secs aft her the beginning of the exercise and this increased remained after the exercise was done. It was noted that when muscle contractions were done in the limb with the MCB in place an increase in colloid reabsorption and transport occurred. In those who only did a muscular contraction with no MCB in place no noted increase in transport occurred. It is recommended to limit the use of MCB with those suffering from lower limb lymphedema.


A study was also done on the types of bandages to use. The pressure was measured at he interface between the bandage and the limb. When the MLB was used the increase was significant at rhe interface and increased tension in the limb. In the elastic bandages it increased pressure at the interface and then plateaued.


Contraindications to MLB:


1) DLA, erysipelas


2) Cardiac condition


3) DVT


4) Arterial perfusions impairment


Contraindications to Pneumatic Pump:


1) DLA, erysipelas


2) Cardiac condition


3) DVT


4) Arterial perfusions impairment


Sheree DiBiase, PT, and her staff can be reached at (208) 667-1988 and they can help you with your physical health challenges. Never give up on your health. It’s your prized possession. Lake City Physical Therapy.