An investigation of lymphatic function following free-tissue transfer

Despite microsurgical advances in the repair of severed arteries, veins, and nerves, disrupted lymphatics are not usually identified or reconnected during replantation. Although temporary swelling of a replanted part is attributed to lymphedema, this condition resolves without microsurgical intervention. Spontaneous regeneration or reconnection of lymphatics is thought to occur in such situations. Microsurgical free-flap transfer is clinically analogous to replantation in that it also results in a complete division of all lymphatic channels exiting the flap. The ability of lymphatics to regenerate after flap reconstruction, either pedicled or free, has received little attention because safe and accurate techniques for visualization and evaluation of the status of these structures have not been available. As a result of recent advances in radiocolloid lymphoscintigraphic imaging techniques, it is possible to demonstrate lymphatic flow in a physiologic, anatomic, and noninvasive manner. These methods can be applied to free-flap models to document lymphatic function after surgical treatment and determine when and to what extent such a process of growth occurs. We studied 10 consecutive patients having free-flap reconstruction. These flaps were performed for chronic osteomyelitis (6) and unstable wound coverage (4). Microvascular flaps used were latissimus dorsi, scapular-parascapular fasciocutaneous, lateral arm, rectus abdominis, temporoparietal, and free toe. Radiocolloid lymphoscintigraphy with technetium-99m-antimony trisulfide colloid (Sb2S3) was done on all patients by injection directly into the free-flap dermis. All patients were studied between 8 and 44 days (mean 23.6) after free-flap transfer. Following injection into each flap, rapid egress of the radiotracer along lymphatic pathways with progression to locoregional nodes was observed in all patients. Reestablishment of lymphatic pathways following microvascular free-tissue transfer was demonstrated by radionuclide lymphoscintigraphic techniques in 10 consecutive patients who had reconstruction for extremity wounds.