Page 16 - Read Online

Page 10 of 13 Liang et al. Plast Aesthet Res 2023;10:71 https://dx.doi.org/10.20517/2347-9264.2023.81

imply that the venules are also reflux-free; ideally, reflux testing should be performed directly on the venules
to be used for LVA. Wongkietkachorn et al. visualized subcutaneous veins using an ICG fluorescence device
[56]
after intravenous injection of 0.1 to 0.2 mg/kg of ICG . With the veins illuminated, reflux is tested by
milking them on the skin. However, using ICG for both venous and lymphatic detection is tricky.
Intravenous ICG can quickly migrate to the soft tissues, obscuring the lymphatics during ICG
lymphography, and similarly, ICG lymphography patterns can mask the visualization of subcutaneous
veins.

Ultrasonography, in contrast, can help visualize both lymphatics and veins independently, along with
determining the presence of reflux in both the main subcutaneous vein trunk and its smaller venular
branches. Using the color Doppler mode, and through a simple maneuver of alternately squeezing and
relaxing the limb distally, reflux venous flow can be detected by a change in the color signal. While positive
Doppler findings are definitive, Rodriguez and Yamamoto listed other ultrasonographic features that may
be associated with reflux-free veins, namely the presence of a hyperechoic wall, subcutaneous location, and
selection of a primary or secondary branch from a larger vein. Conversely, venules with an isoechoic/thin
wall, an immediate subdermal location, or concomitant perforator veins usually have a higher risk of
reflux .
[57]

LIMITATIONS
Some limitations of this study warrant further consideration. Data on the preoperative conservative
management for the patient cohort were not collected in this study. Long-term postoperative data are not
available for every patient due to defaulted follow-ups (especially during the COVID-19 lockdowns) and
surgeries performed more recently. The study analyzed patients with BCRL only; inclusion of other causes
of upper limb lymphedema, as well as comparison with cases of lymphedema of the lower limb, may further
yield results of interest and would be our focus for future research.

CONCLUSION
Preoperative ultrasonography serves as a useful adjunct to detect not only lymphatic vessels, especially
ectasic ones, but also subcutaneous veins, and assess the presence of reflux. No other single imaging
modality has such versatility. In our study, we achieved 62.7% and 92.4% accuracy in detecting lymphatic
vessels and veins, respectively, using preoperative ultrasonography, and our patients showed statistically
significant improvements in mean upper limb circumference. The techniques and methods described herein
to identify lymphatics and non-reflux veins can increase the chances of successfully performing LVA
surgery even in cases of more advanced upper limb lymphedema, which is expected to contribute to better
and more long-lasting outcomes.

DECLARATIONS
Acknowledgments
The authors would like to thank The Takeda Science Foundation for providing international scholar
fellowships and meeting my mentor, Prof. Koshima, in Hiroshima, Japan.

Authors’ contributions
Conception and design: Chang RCH, Koshima I
Data analysis and interpretation: Chang RCH, Liang WH
Data acquisition, administrative support: Hung CM
Writing: Liang WH, Chang RCH