Evaluation of the greater omentum in the treatment of experimental lymphedema.

Despite advances in microsurgery, the most suitable operation for primary lymphedema remains unclear. A variety of tissue transplants and artificial substances have been used to facilitate drainage of peripheral lymph. The greater omentum, for example, has absorptive lymph draining capability, fights infection, and is expendable for the abdomen. Previous attempts to use the omentum in treatment of clinical lymphedema have, however, been disappointing. This discrepancy between theory and outcome prompted us to reevaluate the role of the omentum in the treatment of chronic lymphedema. In rabbits, mobilization of omentum was carefully examined by three separate techniques and the presence of natural lymph nodal-venous (L-V) shunts determined by an injection of Evans blue into the omentum with sampling later of plasma from the gastroepiploic venous blood. In dogs after promotion of unilateral chronic hindlimb lymphedema by soft tissue excision and sclerosis, the results of four methods of omental transplantation with or without L-V shunt for relief of lymphedema were compared. The results in rabbits suggest that although the greater omentum can be lengthened without jeopardizing its blood supply, it is inappropriate to lengthen it based on blood vascular arcades alone because the omental lymphatics do not strictly follow these arcades in the more distal portion, and with elongation, may be interrupted even though the blood supply remains intact. Moreover, because there is no natural L-V shunt within the greater omentum, the addition of a L-V shunt in dogs in addition to omental transplantation seems to increase effectiveness of the omentum for draining hindlimb lymph after its autotransplantation.