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Page 4 of 14 Olla et al. Plast Aesthet Res 2024;11:24 https://dx.doi.org/10.20517/2347-9264.2024.30

This enables the identification of even the smallest perforators, which can be easily distinguished from the
background of fat or muscle, allowing for clearer visualization of the perforator intramuscular course
[33]
without the need for radiation .

Overall, MRA studies provide optimal preoperative imaging, given their high-definition visualization of
perforator anatomy using 3D reprocessing techniques. In MRA reports, the overall mapping of the
perforators is accurate and the level of detail for each perforator is unmatched. Accurate identification and
selection of perforators, detail of the intramuscular course, and perforator length allow for reliable marking
and planning of the location of the skin paddle. This is particularly helpful when planning a transverse PAP
(tPAP) flap, as the dominant perforator must be found within 5-6 cm of the inferior gluteal crease (IGC) to
ensure the resulting scar lies in the ICG. When the dominant perforator is not in proximity to the IGC, a
diagonal PAP (dPAP) flap can be planned to include the lower dominant perforator.

RELEVANT VASCULAR ANATOMY
As it passes under the inguinal ligament, the external iliac artery becomes the common femoral artery.
Approximately 1-4 cm distal to the inguinal ligament, the common femoral artery bifurcates into the
femoral artery and the profunda femoris artery. The femoral artery continues to travel superficially without
any major branches to the thigh and distally transitions to the popliteal artery passing through the adductor
[34]
hiatus . The profunda femoris artery takes a posterolateral trajectory between the pectineus and adductor
longus muscles, entering the posterior compartment of the thigh and providing significant blood supply to
[35]
the proximal lower extremity . The medial and lateral circumflex femoral arteries are the most proximal
branches of the profunda. Progressing distally, the profunda femoris typically gives off three lateral branches
before terminating as a fourth perforating vessel. The first branch supplies the adductor muscles and the
gracilis, while the second and third branches nourish the biceps femoris, semimembranosus, and vastus
lateralis. Each of these branches contributes a septocutaneous and/or musculocutaneous perforator,
supplying the skin of the posterior thigh [34,35] . The number of adequate perforators varies by patient, with
most patients having at least two but as many as five perforators [33,34] . Perforators are commonly located
along the axis extending from the ischium to the lateral femoral condyle, with the initial skin perforator
typically found within 8 cm of the IGC [32,34,36] . The length of the pedicle typically ranges from 8 to 13 cm .
[4]
Arterial and vein diameters measure around 1.5 to 2.4 mm and 1.8 to 3.0 mm, respectively [23,26] .

OPERATIVE TECHNIQUE
Flap designs
The transverse PAP (tPAP) consists of a crescent-shaped skin paddle based on a PAP perforator in the
proximal thigh. The tPAP design allows for scars to be discreetly placed along the IGC, but the width of the
flap is limited to only 6-8 cm to ensure that closure can be achieved without excess tension. Although the
transverse scar design is more easily hidden within the IGC, it is subjected to significant tension especially
when the patient is in a seated position. Due to the location of the skin paddle, there is also a risk of
[19]
paresthesias to the posterior thigh if there is an injury to the posterior cutaneous nerve .
The vertical PAP (vPAP) flap has a modified skin paddle orientated in a longer vertical dimension to allow
for increased dissection and flap volume. This orientation provides the surgeon with more distal perforator
options and a resulting scar that can be hidden in the medial thigh [37,38] .

The “fleur-de-lis” modification of the PAP flap (the “fleur-de-PAP”) combines the principles of the tPAP
and vPAP to maximize the soft tissue volume from one donor site but results in vertical and horizontal
scars . This option is ideal for the massive weight loss patient with excess, loose skin in multiple planes of
[39]