Lymphatic anatomy of the inguinal region in aid of vascularized lymph node flap harvesting

Background Vascularized lymph node transfer (VLNT) has shown promise as a treatment for breast cancer-related lymphedema, a common and debilitating condition among breast cancer survivors. In VLNT, the most popular lymph node flap donor site is the inguinal region; however, concerns about the possibility of iatrogenic lymphedema hamper the widespread adoption of VLNT. A better understanding of the anatomy of the lymphatic system in the inguinal region is essential to preserving lymph drainage in the leg and avoiding iatrogenic lymphedema. Methods Five human cadaver hind-quarter specimens were used for this study. First, the specimens were scanned with indocyanine green fluorescence lymphography to map the lymphatic vessels. A dual injection technique using different radiocontrast media was then applied to delineate arteries and lymphatic vessels on radiographs. Finally, radiological analysis and meticulous dissection were used to investigate relationships between the arteries and lymphatic vessels. Results By chasing the lymphatic vessels retrogradely from their corresponding lymph nodes, we were able to divide the superficial inguinal lymph nodes into three subgroups: the abdominal, medial thigh, and lateral thigh nodes. We found no connections between the superficial and deep lymphatic system in the inguinal region. The dominant lymph nodes draining the leg were in the lower part of the inguinal triangle, and their efferent lymphatic vessels ran medial to the common femoral artery. Conclusions Preserving the sentinel nodes of the lower leg in the medial thigh and their efferent lymphatic vessels is crucial to avoid iatrogenic lymphedema in limbs with donor sites for VLNT.