Lymphatic-based Lymphosome: A Novel Hypothesis with Clinical Implication for Supermicrosurgical Lymphaticovenous Anastomosis

Abstract

Summary: Understanding the anatomical territories drained by lymphatic vessels (LVs) is essential for a better comprehension of lymphatic anatomy and functionality, and for performing lymphatic procedures such as lymphaticovenous anastomosis (LVA). However, current concepts regarding the lymphatic territory are insufficient to explain some of the clinical observations. As shown in the figures, within one incision for the LVA, one to two lymphatic vessels (LV) remained unenhanced on indocyanine green (ICG) lymphography, whereas the rest of the LVs were enhanced. To answer this question, one must examine the concept of the lymphosome, first described by Suami, defined as a particular region drained by LVs into the same subgroup of regional lymph nodes (LNs) (eg, superficial groin LNs). Suami’s lymphosome concept represents “LN-based lymphosomes.” In addition, Shinaoka identified four distinct lymphatic groups (anteromedial, anterolateral, posteromedial, and posterolateral) in the lower limbs after ICG injection. This represents the concept “group-based lymphosomes.” Nevertheless, neither the LN- nor group-based lymphosome concepts offer an appropriate explanation for the clinical findings described above. In addition to the aforementioned lymphosome concepts, the author proposes a novel hypothesis called “lymphatic-based lymphosome,” which considers each LV as a single lymphosome. Therefore, the normal-type LV remained unenhanced when ICG was not injected into the draining territory. To enhance post-LVA outcomes, an even distribution of anastomoses to different group-based lymphosomes is important, as is avoiding performing all anastomoses onto a single LV or within the same group-based lymphosome.