Technique and proof of patency of microsurgical lympho-lymphonodular anastomoses: A study in the rat model

Background: Lymphedemas due to local lymphatic blocks can be treated by microsurgical transplantation or transposition of lymphatic vessels. Here, the anastomoses are usually made end‐to‐end between lymphatics, but occasionally appropriate lymphatic recipient vessels are missing. In such cases, reconstructing lymph drainage by connection to a lymph node could be another technical option. The purpose of this study was to examine the patency rate of such lympho‐lymphonodular anastomoses in an experimental animal model. Methods: Male Sprague–Dawley rats were anesthetized, and the retroperitoneum was exposed. Patent blue dye was injected into the left foot to stain lymphatic structures. In group A (n = 8), the left lumbar trunk was cut centrally, the distal part was turned over to the right lumbar lymph node, and a microsurgical lympho‐lymphonodular anastomosis was performed. In group B (n = 8), the left lumbar trunk was cut. After 8 weeks, the lumbar region was surgically re‐explored, and the lymphatic drainage was examined by injection of Patent blue dye into the left lumbar lymph node. Results: In 8/8 animals of group A, patent transposed lymphatics were found. The patency of the anastomosis was proven directly by observation of blue dye transit and indirectly by observation of blue staining of the right lumbar lymph node. In 6/8 animals of group B, no lymphatic connection to the right lumbar lymphatic system was observed. Conclusions: This is the first report of the microsurgical technique and the proof of patency of lympho‐lymphonodular anastomoses. The novel animal model for testing the patency of transposed lymphatics is discussed. © 2009 Wiley‐Liss, Inc. Microsurgery, 2009.