Experimental study on the microsurgical or spontaneous formation of lympho-lymphonodular anastomoses in the rat model

Summary Background The restoration of the lymphatic function in chronic lymphoedemas can be achieved by microsurgical lymphatic vessel transplantation. Usually, end-to-end anastomoses are performed between the lymphatic vessels. Sometimes, the lack of appropriate lymphatic recipient vessels impels the idea of connecting the grafts to local lymph nodes. This study focusses on the microsurgical completion of durable lympho-lymphonodular anastomoses and further the detection of a spontaneous formation. Methods In 36 Sprague-Dawley rats the retroperitoneal lymphatic structures were prepared after staining with patent blue V dye. In group A ( n  = 12), the left lumbar trunk was cut cranially and its distal part was turned over to the right lumbar lymph node where a microsurgical lympho-lymphonodular anastomosis was performed. In group B ( n  = 12), treatment was similar but without anastomosing. In group C ( n  = 12), the left lumbar trunk was transected and the capsule of the contralateral lumbar lymph node was incised. Finally, the lumbar region was re-exposed and the lymphatic drainage was examined using patent blue in four animals of each group after 8, 12 and 16 weeks, respectively, to examine the development of possible spontaneous formations of lymphatic connections. Results In 12/12 animals of group A, patent transposed lymph vessels and anastomoses with blue staining of the right lumbar lymph node were observed. Only 1/12 animals of group B and 2/12 animals of group C showed a blue staining of the right lumbar lymph node. Conclusions The microsurgical fabrication of lympho-lymphonodular anastomoses leads to a safe and durable lymphatic connection. The known plasticity of lymphatic vessels with the potential of spontaneous anastomosing seems to be higher between lymphatic vessels than between lymphatic vessels and a lymph node.