Vein and Lymphatic Pathology

Deep vein thrombosis (DVT) is a blood clot in the deep veins, usually in the lower extremities (though they can occur in the upper extremities, mesenteric, and cerebral veins as well). The affected veins commonly include the popliteal, femoral,  iliac, and pelvic veins. The 3 primary factors (known as the Virchow triad) that contribute to DVT formation include: venous stasis, hypercoagulability, and vascular endothelial damage. Any condition that worsens 1 (or more) of these 3 factors increases the risk of DVT formation. Individuals can present with unilateral extremity pain, swelling, and/or redness around the DVT; however, a majority of cases are asymptomatic. Ultrasound can visualize the thrombus. Anticoagulation is the primary mode of treatment; the main objective is preventing a pulmonary embolism (PE).

Chronic venous disease is a spectrum of disorders characterized by venous dilation and/or abnormal vein function in the lower extremities resulting from venous hypertension. "Chronic venous insufficiency" refers to the more severe forms of chronic venous disease. Skin changes typically distinguish chronic venous insufficiency from milder forms of venous disease (like varicose veins) and include skin pigmentation, stasis dermatitis, lipodermatosclerosis, and eventually, the development of ulcers. Diagnosis is usually based on physical exam findings alone, although venous duplex ultrasonography can provide additional information about the etiology, location, and extent of disease. The mainstay of management is compression therapy. A variety of surgical options also exist for symptomatic patients, including ablation, sclerotherapy, and valve repair. Venous ulcers are common as the disease progresses and are often very difficult to treat.

Portal hypertension is increased pressure in the portal venous system. This increased pressure can lead to splanchnic vasodilation, collateral blood flow through portosystemic anastomoses, and increased hydrostatic pressure. There are a number of etiologies, including cirrhosis, right-sided congestive heart failure, schistosomiasis, portal vein thrombosis, hepatitis, and Budd-Chiari syndrome. Most individuals are asymptomatic until complications arise, including esophageal varices, portal hypertensive gastropathy, ascites, and hypersplenism. The diagnosis is clinical, but it can be supported by ultrasound findings (and hepatic venous pressure gradient measurement in unclear cases). Management requires treating the underlying etiology and managing the complications. This can include nonselective beta blockers to prevent bleeding from varices, diuretics and sodium restriction for ascites, and transjugular intrahepatic portosystemic shunt for refractory complications.

Lymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Diagnosis relies on a thorough medical history and physical examination, which usually identify the underlying cause. When the cause is unknown, a biopsy may be necessary. Management is directed at the underlying infection, malignancy, or other cause.

The lymphatic system consists of the lymphoid organs containing the cells of the immune system and the lymphatic vessels, which transport interstitial fluid (as lymph) back to the venous circulation. Lymphatic vessels are spread extensively throughout the body, draining and filtering lymph, facilitating homeostasis, and aiding in defense against circulating pathogens. Fluid flow is unidirectional, enabled by valves in the collecting lymphatic vessels. In vessels without valves, the muscle contraction of organs and adjacent blood vessels help in the fluid movement. To return to the venous circulation, the lymph is collected by the major lymphatic ducts: right lymphatic duct (collects from the right side of the head and neck, the right side of the thorax, and the right upper extremity) and the thoracic duct (collects from the rest of the body). Pathologic conditions involving the lymphatic system are associated with infections, lymphatic damage, or injury and malignancies.

Chronic venous disease is a spectrum of disorders characterized by venous dilation and/or abnormal vein function in the lower extremities resulting from venous hypertension. "Chronic venous insufficiency" refers to the more severe forms of chronic venous disease. Skin changes typically distinguish chronic venous insufficiency from milder forms of venous disease (like varicose veins) and include skin pigmentation, stasis dermatitis, lipodermatosclerosis, and eventually, the development of ulcers. Diagnosis is usually based on physical exam findings alone, although venous duplex ultrasonography can provide additional information about the etiology, location, and extent of disease. The mainstay of management is compression therapy. A variety of surgical options also exist, including ablation, sclerotherapy, and valve repair. Venous ulcers are common as the disease progresses and are often very difficult to treat.

The lower leg, or just “leg” in anatomical terms, is the part of the lower limb between the knee and the ankle joint. The bony structure is composed of the tibia and fibula bones, which articulate with each other at the proximal and distal tibiofibular joints. The muscles of the leg are grouped into the anterior, lateral, and posterior compartments by extensions of fascia and exert their action on the ankle, foot, and toes.

Deep vein thrombosis (DVT) usually occurs in the deep veins of the lower extremities. The affected veins include the femoral, popliteal, iliofemoral, and pelvic veins. Proximal DVT is more likely to cause a pulmonary embolism (PE) and is generally considered more serious. Ultrasound can visualize the thrombus and anticoagulation is the primary mode of treatment; the main objective is the prevention of development of a PE.