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Pandey et al. Plast Aesthet Res 2021;8:47 https://dx.doi.org/10.20517/2347-9264.2021.61 Page 7 of 12

Technical tips: VLVT
Due to its comparable outcomes and lower invasiveness, SCIP-based VLVT has replaced VLNT as our
procedure of choice for those with upper extremity lymphedema who are not LVA candidates. Vascular
anatomy is imaged preoperatively with computed tomography angiography or high-resolution duplex
[67]
ultrasound , allowing the more robust-appearing side to be chosen for harvest. Lymphatic vessels are then
mapped using ICG imaging after four intradermal injections of 0.05 mL of 0.25% ICG, lateral to the anterior
superior iliac spine. Most frequently, the superficial branch of the superficial circumflex iliac artery (SCIA)
is selected as the pedicle due to its fast and easy dissection. One should be prepared for occasional anatomic
variation necessitating the use of a deep branch. The dissection plane is kept immediately superficial to
Scarpa’s fascia, ensuring the exclusion of lymph nodes from the flap and is advanced in a lateral-to-medial
direction. It is important to adhere to Scarpa’s fascia during flap elevation and not dissect more superficially
as more superficial dissection risks exclusion of the superficial circumflex iliac vein.

The vascular anatomy and perforator location of the TDAP flap is more variable than that of the SCIP flap.
Thus, preoperative vascular imaging becomes even more important. Adequate perforators are commonly
identifiable with Doppler ultrasound, 8-10 cm inferior to the axillary apex and 1-2 cm inside the lateral
border of the latissimus dorsi. Perforators identified in this region may originate from intercostal and lateral
thoracic vessels rather than from the thoracodorsal vessel, as shown in Figure 5. However, if adequate
pedicle length can be achieved, harvesting the flap on these alternative vessels is acceptable [68,69] . Lymphatics
are mapped with intradermal ICG injection of the fifth intercostal space in the midaxillary line to ensure
their inclusion in the flap. By dissecting superficial to the superficial fascia, lateral thoracic lymph nodes are
excluded from the flap.

For VLVT to be effective, the flap is placed closer to lymphatic edema, and in the proximity of relatively less
degenerated lymphatics, both criteria are met in the distal part of the extremity (ankle/wrist). the flap is
oriented to match its lymphatics vessels axiality to that of the recipient site lymphatics axiality to allow
spontaneous lympholymphatic linkages, as shown by Yamamoto et al. . Just as the minimum number of
[38]
lymph nodes required for optimum performance of VLNT is not known, the minimum number of
lymphatic channels needed for optimum efficacy VLVT is unknown. The density of lymphatic channels in
the different flap donor sites has not been experimentally compared, and the minimum size (volume) of the
flap required for desirable lymphatic decompression is unclear.

Decision-making: choosing between LVA and VLVT
Both LVA and VLVT are indicated for fluid-predominant lymphedema. Solid predominance, a state of
bulky lipodystrophy and fibrosis, should be ruled out clinically (non-pitting edema, no significant volume
reduction even after aggressive complex decongestive therapy) [4,70] as well as radiologically with MRI before
proceeding.

Misconceptions surrounding LVA have hindered its acceptance amongst surgeons. It is assumed that LVA
can only treat early lymphedema and that absence of “linear” patterns on ICG lymphography and/or the
presence of venous insufficiency contraindicate its use. Additionally, a few studies have demonstrated
inferior outcomes of LVA in lower extremity vs. upper extremity edema, thought to be due to the
dependent position and higher venous pressure of the legs [71-75] . Finally, it is also believed that results of LVA
take long to become noticeable and are short-lived. In the senior author’s experience, none of the above
holds true. The absence of “linear” ICG patterns simply indicates additional effort is needed to locate the
lymph vessels, which, once located, are still of sufficient quality to perform LVA. The reduced
lymphovenous pressure gradient in the lower extremity can be circumvented with postoperative bandage
compression, which creates anterograde flow across the LVAs [53,69,73] . Finally, the senior author has witnessed