Lymphedema, also known as lymphatic obstruction, is a condition in which lymph does not return to the bloodstream via the thoracic duct as normal, but collects in the interstitial tissue and causes swelling that can lead to decreased function, mobility, and other complications. While most often associated with breast cancer, lymphedema can result from treatment for other cancers, infection, trauma, scar tissue, parasitic infections, or anything that changes, blocks or interrupts the flow of lymph through the lymphatic system. The greater the number of lymph nodes removed, the higher the risk for developing lymphedema. Between 38 and 89% of breast cancer patients suffer from lymphedema due to auxiliary lymph node dissection and/or radiation.
Over the past decade, lymphatic supermicrosurgery or supermicrosurgical lymphaticovenular anastomosis (LVA) is gaining popularity as one treatment for upper extremity lymphedema (UEL) that does not respond to compression treatment. In LVA, lymphatic vessels are anastomosed to veins in order to shunt the lymph into the venous drainage system.
Supermicrosurgery is performed by highly skilled surgeons such as Dr. Koshima (Univ. of Tokyo), the founder of supermicrosurgery, and Dr. Chen (Univ. of Iowa). In the 2015 Journal of Plastic, Reconstructive and Aesthetic Surgery, Dr. Chen reports on his direct measurements of lymph to assess the health and function of the lymph vessel both before and after constructing an anastomosis with a 7 mm transit time ultrasound Flowprobe and the Transonic AureFlo®
. Previously, surgeons had to rely on visually observing the blood “wash out” of a vein to decide if a lymphedema anastomosis was patent.
Dr. Chen measured and assessed a total of 28 lymphatic vessels and constructed 15 LVAs. He used the mean ﬂow values based on three consecutive measurements and then compared the results obtained from the flow measurements with his own visual assessments. Lymph flow ranged from 0 to 1.2mL/min, and the LVA ﬂows ranged from 0.22 to 1.4mL/min.
From this experience, Dr. Chen concluded that transit-time ultrasound technology (TTUT), with its sensitivity reaching 0.01 mL/min, offers promise for guiding lymphatic vessel selection; confirming anastomotic patency and not having to rely on “wash out” alone to make surgical decisions.