Exclusive use of ultrasound for locating optimal LVA sites-A descriptive data analysis

The current standard to locate lymphatic vessels for lymphovenous anastomosis (LVA) is the use of indocyanine green (ICG)-lymphangiography. Due to fluid retention and fibrosis of tissue in patients with lymphedema, often present in Caucasian patients, vessels deeper than 0.5 cm below the dermis cannot be visualized. We present our experiences with ultrasound in locating deeper lymphatic vessels in lower extremities.

In total, 28 patients with lymphedema and positive lymphoscintigraphy were included. With ultrasound, we located 82 lymphatic vessels in lower extremities preoperatively without the use of ICG marking. Vessel diameter, depth, and exact location were examined. Using a coordinate system, a mapping of the detected lymphatic vessels was created. The ultrasound findings were confirmed under microscope and ICG intraoperatively.

In all, we detected 28 Caucasian patients and 82 lymphatic vessels with ultrasound preoperatively. On average, we found three lymphatic vessels (range, 2-6) at each patient. Of the ultrasound-detected lymphatic vessels, 90.2% could be verified intraoperatively under a microscope. Before skin incision, lymphatic vessels could be visualized in 40% of our patients with ICG. In the mapping of the lymphatic vessels, we found no significant pattern.

Ultrasound can precisely detect lymphatic vessels for efficient LVA operation without the prior use of ICG-lymphangiography.