Background Lower extremity edema remains a major postoperative complication after inguinal lymphadenectomy for vulvar cancer. This study documents the lymphatic drainage of the vulva versus the lymphatic drainage of the lower extremity coming through the femoral triangle.

Methods Seven patients underwent either unilateral or bilateral inguinal lymphadenectomy in conjunction with a radical vulvar resection. Preoperatively, patients had technetium-99 injected into the vulvar cancer. Isosulfan blue was injected into the medioanterior thigh 10 cm below the inguinal ligament. The femoral triangle was opened, and a neoprobe was used to locate the "hot" node bearing the technetium-99. Gentle dissection located the blue lymphatic channel and any blue lymph nodes. The blue and hot nodes were resected and submitted separately. The patients then underwent a complete inguinal lymphadenectomy.

Results A total of 11 groin dissections were performed. In 9 of the 11 groins, the hot node was identified, and in 8 of the 11 groins, blue node or lymphatic channel was identified. The hot nodes were uniformly located on the superior medial aspect of the femoral triangle. The blue nodes were uniformly located on the lateral aspect of the femoral triangle just anterior to the femoral artery or vein. Three patients had hot lymph nodes containing cancer. Of those 3 patients, one had an additional node positive. None of the blue lymph nodes contained cancer.

Conclusions This procedure demonstrates the alternative lymphatic drainage of the leg versus the vulva. Larger studies are necessary to document the exclusivity of these 2 drainage systems. Preservation of the lymphatic drainage of the leg may result in decreased lymphedema.