A simple, inexpensive method for producing an experimental model for lymphedema in rabbit ear is described. In 47 of 50 rabbit ears, the lymphedema could be demonstrated by measurement of ear thickness, water displacement, skin thickness, diameter of lymphatics, and histopathology of the experimental ear. Three rabbit ears failed because of technical reasons. In studying the findings of experimental lymphedema, some clinical phenomena are explained and modifications of the operative procedure of microlymphaticovenous anastomosis for treating lymphedema are suggested.

A simple, inexpensive method for producing an experimental model for lymphedema in rabbit ear is described. In 47 of 50 rabbit ears, the lymphedema could be demonstrated by measurement of ear thickness, water displacement, skin thickness, diameter of lymphatics, and histopathology of the experimental ear. Three rabbit ears failed because of technical reasons. In studying the findings of experimental lymphedema, some clinical phenomena are explained and modifications of the operative procedure of microlymphaticovenous anastomosis for treating lymphedema are suggested. T h e investigation of lymphodynamics and pathogenesis of lymphedema makes it desirable to produce an experimental model for lymphedema. For the past half century, many methods have been used to produce the model, but none has been entirely satisfactory. It is owing to the regeneration of lymphatics that the severed lymph vessels are reconstituted to functional or anatomic perfection in most instances. In 1974, Clodius and Wirth6 made an experimental dog model by a circular excision of tissue in the thigh followed by insertion of a synthetic implant to prevent regeneration of lymphatics. Successful as it was, the method was expensive and difficult to reproduce. We used rabbit ears to produce experimental lymphedema for investigating lymphodynamics and microlymphatic techniques; this resulted in lower cost and a higher success rate. In 47 of 50 rabbit ears, the lymphedema could be demonstrated through 6 months of observation. Three rabbit ears failed because of technical reasons. This article reports our experience in producing the rabbit ear model of lymphedema and summarizes our findings in studying experimental lymphedema. MATERIALS AND METHODSFifty white Japanese rabbits, 6 to 12 months of age, 3 to 4 kg in weight, were used. Both ears were shaved to facilitate measurements of water displacement and thickness. The rabbit was fixed in a special wooden box, and one ear was operated on; the contralateral ear served as a control. The operation was performed with local anesthesia, with 4 ml 1 % procaine being infiltrated subcutaneously around the base of the ear. A 1-cm circumferential strip of skin, subcutaneous tissue, and perichondrium was excised 2 cm from the base of the ear; the neurovascular bundle protected and the chondrium were preserved. For visualization of lymphatics, 0.5 % methylene blue was injected intradermally into the tip of the ear and 1.5 cm from the tip on both sides 0.2 ml of the dye was injected at each site. Five to seven major lymphatic channels could be clearly visualized due to the uptake of the dye. They converged around the central neurovascular bundle. The neurovascular bundle along with two to four lymphatics was carefully dissected under an operating microscope.Fifty rabbits were divided into two groups: Group A included twenty-five rabbits, in which all lymphatic channels were dissected and resected (a segment of at least 3 cm in length). The lymphatic stumps were ligated and the central neurovascular bundle preserved....