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Page 2 of 11 Baek et al. Plast Aesthet Res 2024;11:49 https://dx.doi.org/10.20517/2347-9264.2024.91

candidates for abdominally-based tissue reconstruction due to the lack of available tissue from a leaner
habitus and/or prior surgeries including open abdominal procedures, abdominoplasty, and liposuction,
which can potentially disrupt vascularity.

Although abdominally-based free flaps for breast reconstruction have been popularized, the first free flap
for breast reconstruction following mastectomy was actually the gluteus maximus myocutaneous flap,
[3]
described by Fujino et al. in 1976 . While the surgery was a technical success, the authors commented that
due to the short pedicle length, the breast mound was superiorly displaced. In 1983, Shaw modified this flap
[4]
with good aesthetic results and well-tolerated donor site morbidity . However, the pedicle length remained
short at 2-3 cm and 7 out of 10 patients required either vein grafts or anastomosis to other recipient veins.
The internal mammary vessels, if used, were at the level of the fifth intercostal rib.

The introduction of gluteal perforator flaps by Koshima et al. in 1993 for sacral pressure injury
reconstruction provided the first opportunity to modify the gluteal myocutaneous flap . They found
[5]
reliable cutaneous perforators in cadaveric dissections for pedicled-flap reconstruction, including ones
based off the superior gluteal vessels supplying the superolateral gluteal tissue. Shortly after, Allen and
[6]
Tucker introduced the superior gluteal artery perforator (SGAP) flap for breast reconstruction . Expanding
on Koshima’s gluteal perforator flap, the previously described gluteal myocutaneous flap was improved by
sparing the muscle to reduce donor site morbidity and thereby increasing the vascular pedicle length up to 8
cm, obviating the need for vein grafts. Blondeel later shared his positive experiences with SGAP flaps as a
[7]
primary option for breast reconstruction in patients who were not DIEP flap candidates .

Since its first introduction, the SGAP flap has gone through other modifications, a common critique of the
flap being its steep learning curve. One such modification is the development of a septocutaneous SGAP
(sc-GAP), which avoids the tedious and difficult intramuscular dissection altogether by following
perforators that travel between the gluteus maximus and medius, while still maintaining adequate pedicle
length . During flap harvest, dissection can also be paired with nervi clunii superioris nerves for a sensate
[8,9]
flap [7,10] .

Although technically challenging, the SGAP flap provides a reliable second choice for autologous breast
reconstruction in women who may not have available abdominal donor sites with outcomes comparable to
other autologous options for breast reconstruction [11-15] .

CLINICAL CONSIDERATIONS
In women where the abdomen as a donor site is contraindicated due to prior surgeries or a relative lack of
abdominal soft tissue, as seen in thinner patients, the SGAP should be considered. The buttock will often
provide an adequate amount of tissue, even in leaner patients, to reconstruct a patient habitus-appropriate
unilateral breast or one that matches the contralateral breast [Figure 1]. In several studies, the average body
mass index (BMI) of patients with SGAPs ranged from 20.2 to 25.5 [7,9,11-14] and flap weight ranged from 190
to 894 grams [6,7,9,13,15] . Because the gluteus maximus muscle is spared, this flap can also be considered for
patients who are more active, compared to other flap options such as TRAM or latissimus dorsi, where
muscle is harvested and may affect an active patient’s lifestyle. Although the donor site morbidity to the
muscle is low, patients must be informed of the possible change in the contour of the buttock, especially in
unilateral reconstruction.