The lymph nodes defend the body against infection by acting as filters to remove foreign substances, by pro-ducing lymphocytes to attack the bacteria, and by producing antbodies which promote immunity. Tissues in the breast are also nourished by fluids which are drained by the lymph channels. These vessels lead to axillary nodes and to the internal mammary nodes which lie along the breastbone. During surgery for breast cancer the axillary nodes are removed to determine the spread of cancer cells. This surgical disection interrupts the lymphatic system in this area and can impair the flow of lymph across the axilla.
Radiation therapy causes scarring of tissue which can further obstruct the lymphatic pathways.
When normal transport is interrupted, the movement of lymph from the hand and arm is slowed and the fluid accumulates in the tissues resulting in the clinical condition of Lymphedema. Women with congestive heart failure must be closely monitored by their physician. Women with venous or arterial obstruction or acute infection should not be treated until these conditions have been resolved. Women on anticoagulant therapy should rule out deep venous thrombosis. A woman is at risk who has undergone axillary node dissection or radiation to the breast and armpit area.