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Page 2 of 11 Seki et al. Plast Aesthet Res 2021;8:58 https://dx.doi.org/10.20517/2347-9264.2021.80

Keywords: Lymphedema, lymphaticovenular anastomosis, supermicrosurgery, functional LVA, dynamic LVA
method, superior-edge-of-the-knee incision method, surgery

INTRODUCTION
Lymphaticovenular anastomosis (LVA) is widely recognized as a highly effective, minimally invasive
surgical treatment for lymphedema [1-12] , in which a new lymph-to-venous pathway is created at the affected
limb by means of anastomosing the peripheral lymphatic vessel directly into the subcutaneous vein.
Changes of lymph dynamics at the affected limb sometimes reveal an immediate effect, even
intraoperatively.

In a variety of lymphatic surgeries, LVA has the advantages of minimal invasiveness without donor site
morbidity. The therapeutic effect of LVA is obtained relatively early after the operation compared to other
lymphatic surgeries including vascularized lymph node transfer, vascularized lymphatic vessel transfer, and
lymphatic pathway reconstruction by local and free flap transfer [12-15] . LVA can be the first-line surgical
treatment for peripheral lymphedema because of the high therapeutic efficacy with less invasiveness.

The clinical effect of LVA continues for a long time when the lymph-to-venous bypass maintains
continuous lymphatic flow. However, LVA has the risk of occlusion in early-, mid-, or late-postoperative
course [16,17] . That is why the long-term outcome of LVA is not always promised. There are many potential
reasons of postoperative LVA occlusion, which include technical matter in surgery, surgical site infection,
patients’ compliance, lymphatic vessels’ degenerations, postoperative management, changes of
postoperative lymphatic dynamics, lymphedema severity, and selection of LVA location [16-20] . Although the
reasons of postoperative LVA occlusion seem to vary in fundamentals, all occlusion risks are attributed to
the absence of continuous lymph-to-venous flow at the anastomosis.

To keep continuous lymphatic flow at LVA, we developed a new LVA concept of “functional LVA” for
peripheral lymphedema, in which continuous and strong lymph flow at the anastomosis is created
constantly by the muscle pumping power of patients’ natural motions in daily life.

Functional LVA concept
Generally, an important power source to propel lymphatic fluid in the lymphatic system is the smooth
muscle’s power of the lymphatic vessels. In addition, this smooth muscle’s power has an important role in
propelling lymphedematous fluid into the lymph-to-venous bypass of LVA.

However, lymphedema patients reveal sclerosis of the lymphatic vessels with progression of edema [12,18-20] .
Whether lymphatic vessels are sclerosed or not is basically assessed by pathological study. However,
Yamamoto et al. reported an easy way to assess lymphatic sclerosis intraoperatively by the operating
[12]
microscopic features of lymphatic vessel’s wall thickness, appearance, wall expandability, and status of
lumen. These lymphatic vessels with degenerated smooth muscle are an inadequate power source; they are
too weak to propel lymphedematous fluid to the LVA. This limits the therapeutic effect of LVA in patients
with progressive lymphedema. Furthermore, LVAs using these sclerotic vessels are easily occluded
postoperatively.

To overcome the difficulty to treat lymphedema by means of LVA, we developed and reported new LVA
methods by which LVA incisions are placed at the points where patient’s muscle pumping power is enlisted
as an alternative power source to propel lymph to the anastomosed vein [21,22] . This new muscle pumping