Changing the Paradigm: Lymphovenous Anastomosis in Advanced Stage Lower Extremity Lymphedema

Sir: We read with great interest the article entitled “Changing the Paradigm: Lymphovenous Anastomosis in Advanced Stage Lower Extremity Lymphedema” by Cha et al.1 The study suggested that ultrasound and magnetic resonance lymphangiogram investigations prior to functional lymphovenous anastomosis reduced postoperative limb volume and incidence of cellulitis in patients with advanced lymphedema. We agree that lymphovenous anastomosis is applicable to advanced stage lymphedema, with significant postoperative improvement. In postoperative management of severe lymphedema patients undergoing lymphovenous anastomosis, we may be faced with a situation in which the skin color turns red. This peculiar situation should be known by medical staff, including microsurgeons who perform lymphovenous anastomosis. After completion of lymphovenous anastomosis, lymph flows into a recipient vein when lymphatic pressure is higher than venous pressure.2–5 However, when venous pressure is higher than lymphatic pressure, venous reflux takes place; venous blood flows into a lymph vessel.2 Unlike other lymphovenous shunt operations, in which lymphatic tissue is inserted into a larger vein, the lumen of an anastomosis site is covered with the endothelial cells in lymphovenous anastomosis, preventing anastomosis-site thrombosis.3,4 Therefore, when venous reflux takes place, venous blood may retrogradely flow into the collecting lymph vessels distally and even into the most distal lymphatic capillaries without coagulation. Superficial lymphatics filled with red blood cells due to venous reflux cause the red color change in the skin (Fig. 1). This phenomenon is typical after patent lymphovenous anastomosis in severe lymphedema with extensive dermal backflow pattern. An area of red-colored skin usually corresponds to that of dermal backflow pattern. Unlike the case with cellulitis, there is no heat sensation, pain, or tenderness; only the red color change is seen. This color change is usually noticed on postoperative day 1 and lasts for 2 to 4 weeks. To convert the lymph-to-venous pressure gradient, immediate compression should be performed; compression makes only the lymphatic pressure higher, while venous pressure is unchanged.2,5 As the venous reflux phenomenon represents patent anastomosis, continuous pressure creates a favorable lymph-to-venous pressure gradient and continuous lymph-to-venous flow, maximizing the therapeutic efficacy of lymphovenous anastomosis. Venous reflux skin color change is hardly seen in mild lymphedema cases with functional lymphatics, because functional lymphatic valves prevent further venous reflux flow into the distal lymphatic capillaries.3,5Fig. 1.: Red skin color change after lymphaticovenular anastomosis.All medical staff caring for lymphedema patients, especially microsurgeons who perform lymphovenous anastomosis for progressed lymphedema cases, should understand the venous reflux phenomenon and its optimal management. DISCLOSURE The authors have no financial interest to declare in relation to the content of this communication. There were no sources of support for this work. Tomohiro Kojimahara, M.D.Department of Medical Education Reiko Tsukuura, M.D.Department of Plastic and Reconstructive SurgeryNational Center for Global Health and MedicineTokyo, Japan