99mTc sulfur colloid lymphoscintigraphy demonstrating patency of a lymphovenous shunt.

Lymphedema of the lower limb can occur as a result of lymphatic obstruction secondary to malignancy or to lymphatic filariasis in endemic countries. Resistant lymphedema can be treated with microsurgical lymphovenous anastomosis, thus creating a lymphovenous shunt. Patency of these anastomoses cannot be assessed with conventional imaging modalities (lymphangiogram). Lymphoscintigraphy is useful for this purpose. Early visualization of liver and blood pool activity indirectly confirms presence of a patent lymphovenous shunt. We demonstrate the patency of lymphovenous shunt in a 48-year-old woman who underwent microsurgical lymphovenous anastomosis for severe lymphedema of the left lower limb.