Classification of the lymphatic pathways in each lymphosome based on multi-lymphosome indocyanine green lymphography: Saphenous, calf, and thigh (SCaT) classification

Published:April 18, 2021DOI:



      The anatomy of the lymphatic vessels in the extremities is not completely understood. The aim of this study was to elucidate the patterns of the lymphatic pathways of each lymphosome in lymphedematous legs.


      We performed a retrospective study on 630 lymphosomes from 105 patients with leg lymphedema. The mean age of the subjects was 58.9 (range: 20–91) years, and the mean duration of lymphedema was 8.8 (range: 1–91) years. In indocyanine green (ICG) lymphography, we injected ICG into the multi-lymphosome: the first web space of the foot (saphenous lymphosome), lateral ankle (lateral calf lymphosome), and lateral knee (lateral thigh lymphosome). We established the saphenous, calf, and thigh (SCaT) classification based on the lymphatic location: lymphatic vessels on the medial side (type 1) and lymphatic vessels in other locations (type 2).


      In the saphenous lymphosome, 157 lymphatics (95.5%) were type 1. In the lateral calf lymphosome, 164 lymphatics (29.9%) were type 1. In the lateral thigh lymphosome, 148 lymphatics (16.9%) were type 1. The percentage of type 2 lymphatic vessels increased as the lymphoscintigraphic staging progressed.


      The lymphatic vessels in the lymphedematous legs shifted from the medial to the lateral side and finally disappeared in all lymphosomes as lymphedema worsened. We propose the SCaT classification to describe the condition of the lymphatic vessels in each lymphosome with the hope that it becomes a common staging system for sharing information on lymphedema severity among interdisciplinary medical professionals.


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        • Kashiwagi S.
        • Hosono K.
        • Suzuki T.
        • et al.
        Role of COX-2 in lymphangiogenesis and restoration of lymphatic flow in secondary lymphedema.
        Lab Invest. 2011; 91: 1314-1325
        • Bennuru S.
        • Nutman T.B.
        Lymphangiogenesis and lymphatic remodeling induced by filarial parasites: implications for pathogenesis.
        PLoS Pathog. 2009; 5e1000688
        • Mihara M.
        • Hara H.
        • Hayashi Y.
        • et al.
        Pathological steps of cancer-related lymphedema: histological changes in the collecting lymphatic vessels after lymphadenectomy.
        PLoS One. 2012; 7: e41126
        • Yamamoto T.
        • Narushima M.
        • Doi K.
        • et al.
        Characteristic indocyanine green lymphography findings in lower extremity lymphedema: the generation of a novel lymphedema severity staging system using dermal backflow patterns.
        Plast Reconstr Surg. 2011; 127: 1979-1986
        • Maegawa J.
        • Mikami T.
        • Yamamoto Y.
        • Satake T.
        • Kobayashi S.
        Types of lymphoscintigraphy and indications for lymphaticovenous anastomosis.
        Microsurgery. 2010; 30: 437-442
        • Mihara M.
        • Hara H.
        • Araki J.
        • et al.
        Indocyanine green (ICG) lymphography is superior to lymphoscintigraphy for diagnostic imaging of early lymphedema of the upper limbs.
        PLoS One. 2012; 7: e38182
        • Hara H.
        • Mihara M.
        • Seki Y.
        • Todokoro T.
        • Iida T.
        • Koshima I.
        Comparison of indocyanine green lymphographic findings with the conditions of collecting lymphatic vessels of limbs in patients with lymphedema.
        Plast Reconstr Surg. 2013; 132: 1612-1618
        • Mazzei M.A.
        • Gentili F.
        • Mazzei F.G.
        • et al.
        High-resolution MR lymphangiography for planning lymphaticovenous anastomosis treatment: a single-centre experience.
        Radiol Med. 2017; 122: 918-927
        • Liu N.F.
        • Yan Z.X.
        • Wu X.F.
        • Luo Y.
        Magnetic resonance lymphography demonstrates spontaneous lymphatic disruption and regeneration in obstructive lymphedema.
        Lymphology. 2013; 46: 56-63
        • Shinaoka A.
        • Koshimune S.
        • Suami H.
        • et al.
        Lower-Limb lymphatic drainage pathways and lymph nodes: a CT lymphangiography cadaver study.
        Radiology. 2020; 294: 223-229
        • Olry R.
        • Motomiya K.
        • Mascagni P.
        Ernest Alexandra Lauth and Marie Philibert constant Sappey on the dissection and injection of the lymphatics.
        J Int Soc Plastination Vol. 1997; 12: 4-7
        • Scaglioni M.F.
        • Suami H.
        Lymphatic anatomy of the inguinal region in aid of vascularized lymph node flap harvesting.
        J Plast Reconstr Aesthet Surg. 2015; 68: 419-427
        • Pan W.R.
        • Wang D.G.
        • Levy S.M.
        • Chen Y.
        Superficial lymphatic drainage of the lower extremity: anatomical study and clinical implications.
        Plast Reconstr Surg. 2013; 132: 696-707
        • Suami H.
        • Shin D.
        • Chang D.W.
        Mapping of lymphosomes in the canine forelimb: comparative anatomy between canines and humans.
        Plast Reconstr Surg. 2012; 129: 612-620
        • Hara H.
        • Mihara M.
        Multilymphosome injection indocyanine green lymphography can detect more lymphatic vessels than lymphoscintigraphy in lymphedematous limbs.
        J Plast Reconstr Aesthet Surg. 2020; 21 (S1748-6815(20)30041-3)
        • Hara H.
        • Mihara M.
        Multi-area lymphaticovenous anastomosis with multi-lymphosome injection in indocyanine green lymphography: a prospective study.
        Microsurgery. 2019; 39: 167-173
        • Kistner R.L.
        • Eklof B.
        • Masuda E.M.
        Diagnosis of chronic venous disease of the lower extremities: the "CEAP" classification.
        Mayo Clin Proc. 1996; 71: 338-345
        • Ad Hoc Committee, American Venous Forum
        Classification and grading of chronic venous disease in the lower limbs. A consensus statement.
        J Cardiovasc Surg. 1997; 38: 437-441
        • Vermund H.
        Role of radiotherapy in cancer of the larynx as related to the TNM system of staging. A review.
        Cancer. 1970; 25: 485-504
        • International Society of Lymphology
        The diagnosis and treatment of peripheral lymphedema: 2013 Consensus Document of the International Society of Lymphology.
        Lymphology. 2013; 46: 1-11
        • Mihara M.
        • Hara H.
        • Kawakami Y.
        Ultrasonography for classifying lymphatic sclerosis types and deciding optimal sites for lymphatic-venous anastomosis in patients with lymphoedema.
        J Plast Reconstr Aesthet Surg. 2018; 71: 1274-1281
        • Hara H.
        • Mihara M.
        Usefulness of preoperative echography for detection of lymphatic vessels for lymphaticovenous anastomosis.
        SAGE Open Med Case Rep. 2017; 5 (2050313X17745207)