Experimental assessment of autologous lymph node transplantation as treatment of postsurgical lymphedema.

BACKGROUND: The authors' objective was to test whether the transplantation of an autologous lymph node into a nodal excision site in sheep would restore lymphatic transport function and reduce the magnitude of postsurgical lymphedema.
METHODS: As a measure of lymph transport, iodine-125 human serum albumin was injected into prenodal vessels at 8 and 12 weeks after surgery, and plasma levels of the protein were used to calculate the transport rate of the tracer to blood (percent injected per hour). Edema was quantified from the circumferential measurement of the hind limbs.
RESULTS: The transplantation of avascular lymph nodes at 8 (n = 6) and 12 weeks (n = 6) produced lymphatic function levels of 12.3 +/- 0.5 and 12.6 +/- 0.8, respectively. These values were significantly less (p < 0.001) than those measured at similar times in the animals receiving sham surgical procedures (16.6 +/- 0.7, n = 6; and 16.1 +/- 0.7, n = 6, respectively). When vascularized transplants were performed, lymphatic function was similar to the sham controls and significantly greater (p < 0.001) than that of the avascular group (8 weeks, 15.8 +/- 0.9, n = 8; 12 weeks, 15.7 +/- 1.0, n = 10). Lymph transport correlated significantly with the health of the transplanted nodes (scaled with histologic analysis) (p < 0.0001). The vascularized node transplants (n = 18) were associated with the greatest clinical improvement, with the magnitude of edema in these limbs exhibiting significantly lower levels of edema (p = 0.039) than nontreated limbs (n = 18).
CONCLUSIONS: The successful reimplantation of a lymph node into a nodal excision site has the potential to restore lymphatic function and facilitate edema resolution. This result has important conceptual implications in the treatment of postsurgical lymphedema.