Jp. Anthony et al., LYMPHATIC REGENERATION FOLLOWING MICROVASCULAR LIMB REPLANTATION - A QUALITATIVE AND QUANTITATIVE ANIMAL STUDY, Journal of reconstructive microsurgery, 13(5), 1997, pp. 327-330
Lymphatic regeneration following unilateral hindlimb autotransplantati
on was studied in 14 Lewis rats using Technetium-99 radiolabeled sulfu
r colloid (TC-99) lymphoscintigraphy and compared to the lymphatic pat
tern exhibited in four unoperated control rats. Control animals demons
trate a reproducible flow of lymph along the deep lymphatic system fro
m the foot, draining into the ipsilateral inguinal nodes, and then up
to the para-aortic nodes. Following replantation, lymphatic outflow fr
om the replanted limb begins to occur within 3 to 6 days, reaching nor
mal lymphatic clearance within 12 days However, the pattern of lymphat
ic flow is ill-defined, relying on multiple small channels of the supe
rficial lymphatic system. In contrast to controls, at 3 hr post TC-99
injection, lymphatic drainage in replanted rats is via the inguinal an
d axillary nodal regions bilaterally. This abnormal pattern persisted
in the replanted animals for the duration of this study, 160 days. It
is evident that lymphatic regeneration in this animal model is associa
ted with a rapid return to normal levels of lymphatic clearance via co
llateral channels within the subcutaneous tissue. The rapidity with wh
ich lymphatic drainage is restored, and its localization within the su
bcutaneous tissue, can explain why replanted tissues and microvascular
free flaps seldom develop lymphedema. In addition, the rat hindlimb r
eplantation model may prove useful for studies of the general mechanis
ms and specific factors responsible for lymphangiogenesis.