Fresh and refrigerated cadaveric preparations are ideal for experimental sentinel lymph node mapping in dogs

To identify optimal cadaveric preparation methods for sentinel lymph node mapping in experimental procedures.

Apparently healthy canine cadavers were obtained from local shelters following humane euthanasia unrelated to the study. This experimental study was conducted from October 2023 through July 2024 at the University of Florida College of Veterinary Medicine. Cadaveric preparations were categorized as follows: fresh, refrigerated, frozen-thawed, and heated (refrigerated and frozen specimens). Indocyanine green (ICG) was injected into established lymphosomes, targeting the superficial cervical, axillary, superficial inguinal, and popliteal lymph nodes. Lymphatic tracts were identified using near-infrared fluorescence. Time to lymph node uptake or cessation of tract progression and tract distance (centimeters) was recorded to calculate velocity (cm/s) when applicable. Lymph nodes were then extirpated to assess fluorescence.

9 adult mixed-breed canine cadavers were used, with a lymph node distribution of 11 fresh, 30 refrigerated, 3 refrigerated-heated, 17 frozen-thawed, and 3 frozen-thawed-heated specimens. Fresh and refrigerated cadavers demonstrated consistent and reliable uptake of ICG into the lymphatic tracts and the respective lymph nodes. Frozen-thawed cadavers demonstrated consistent lymphatic tract uptake but inconsistent uptake to the respective lymph nodes. Heating did not improve lymph node fluorescence in refrigerated or frozen-thawed cadavers.

Fresh and refrigerated cadaveric preparations are ideal for sentinel lymph node mapping with ICG. Heating of the cadavers did not improve lymph node fluorescence.

When fresh canine cadavers are not accessible, refrigerated cadavers can be reliably used for experimental peripheral sentinel lymph node mapping.