Characteristic indocyanine green lymphography findings in lower extremity lymphedema: the generation of a novel lymphedema severity staging system using dermal backflow patterns.

BACKGROUND: Indocyanine green lymphography has been a highly useful modality in the clinical examination and surgical management of patients with lymphedema. No formal classification system of indocyanine green imaging findings according to the severity of lymphedema exists, however. The purpose of this study was to describe, analyze, and classify characteristic indocyanine green lymphography findings to uniformly guide surgical management of lymphedema using this modality.
METHODS: Forty-five patients (78 limbs) with lower extremity lymphedema underwent indocyanine green lymphography. All lymphography images were recorded in photographs and videos. Images were reviewed and analyzed to classify characteristic findings according to clinical severity as determined by Campisi clinical lymphedema staging.
RESULTS: Lymphography findings were classifiable into two patterns. Mild cases of lymphedema were characterized by a linear lymphatic channel pattern (linear pattern). In more severe cases, lymphatic channels demonstrated retrograde lymphatic flow (dermal backflow pattern) and diminution or absence of linear channel patterning. Three dermal backflow patterns, splash, stardust, and diffuse, were identified and correlated with the progression of lymphedema severity. These findings supported the generation of a novel anatomical lymphedema severity staging system, the dermal backflow staging system.
CONCLUSIONS: Indocyanine green lymphography is a safe, minimally invasive, and useful tool for the surgical evaluation of extremity lymphedema. Characteristic indocyanine green lymphography patterns are consistent and correlate with clinical severity. The dermal backflow staging system can facilitate patient stratification, discussion between referring parties, and surgical planning.