Visualization of Accessory Lymphatic Pathways in Secondary Upper Extremity Lymphedema Using Indocyanine Green Lymphography.

Abstract

The anatomical variations in accessory lymphatic pathways around the axillary region may work as a drainage route for excess lymphatic fluid accumulation in secondary upper extremity lymphedema. In this report, accessory lymphatic pathways extending to the shoulder, neck, and breast regions in secondary upper extremity lymphedema patients are shown using indocyanine green (ICG) lymphography. Between January 2012 and May 2015, 30 limbs of 29 patients with upper extremity lymphedema after malignant tumor resection were evaluated. ICG lymphography was performed after chronic lymphedema formation. Of the 30 limbs, accessory lymphatic pathways were identified across the axillary region in 3 patients using ICG lymphography. In 2 of these 3 patients, accessory drainage lymphatics were connected to the cervical lymph nodes. In regard to the distribution of dermal backflow patterns, dermal backflow appeared in 26 patients-in the forearm in 26 patients and in the upper arm in 20 patients. Accessory lymphatic pathways are thought to be the drainage routes in the affected arm, which may prevent edema progression to the terminal stage. Variations in the lymphatic system are easily visualized using ICG lymphography. Understanding of accessory lymphatic routes in lymphedema patients may provide new insight for further understanding the pathophysiology of lymphedema.