Page 57 - Read Online

Page 8 of 11 Baek et al. Plast Aesthet Res 2024;11:49 https://dx.doi.org/10.20517/2347-9264.2024.91

Markings
Once the patient has been adequately positioned, the septocutaneous perforator should be identified by
pencil Doppler and this should be confirmed with preoperative computed tomography angiography (CTA)
for appropriate selection. The flap design should again be centered around this perforator. Because of the
more supero-lateral location of this perforator, the flap is designed as an elliptical island oriented in a more
[8,9]
horizontal fashion . Although no exact measurements of the skin islands have been recorded, a pinch test
can ensure that the width will not be too large to close .
[19]
Surgical technique
The incision will begin at the cranial edge of the flap. Unlike the traditional musculocutaneous SGAP,
undermining or beveling is generally not recommended due to the potential for creating a depressed scar
[8]
along the hip . The flap is dissected down to the superior margin of the gluteus maximus and the fascia is
incised. Taking the dissection caudally toward the inferior edge, the septocutaneous perforator is identified,
emerging from the plane and the fascial band connecting the gluteus medius and maximus. A cuff of fascia
may be taken with the pedicle due to the thickness of this fascial connection and the dissection is taken
further in the intermuscular space. As described above, there is a venous plexus submuscularly deep to the
sacral fascia that may need to be dissected away to obtain more length and improve the diameter of the
pedicle. Pedicle length will average between 7.4 and 7.8 cm, with vessel sizes ranging from 1.8 to 3 mm.
Intraoperative indocyanine green can be performed at this time to ensure adequate perfusion prior to flap
harvest. Once the flap is harvested, the donor site is closed in a layered fashion over a closed suction drain.
Microsurgery and flap inset are performed in a similar fashion as described in the previous section.

POSTOPERATIVE CONSIDERATIONS
Patients should remain on bed rest overnight following their surgery. Due to the muscle-sparing technique
in both the traditional SGAP and the sc-GAP, patients are able to mobilize, including ambulation, as early
as postoperative day 1. To avoid tension on the donor site closure, they should avoid sitting completely
upright for the first 2 weeks. Compression garments are not necessary but may help prevent the
development of seromas at the donor site.

CLINICAL OUTCOMES AND COMPLICATIONS
Flap success rates for SGAPs are generally between 93% to 98% [7,12-14] . Both venous and arterial thrombosis
can occur with no propensity for either. Hunter et al. compared DIEP flaps and SGAP flaps and found that
there were no differences between rates of seroma, hematoma, delayed healing, partial flap loss or total flap
loss, as well as arterial and venous thrombosis .
[14]
Donor site seromas are commonly reported, ranging from as low as 2% to as high as 35% [7,9,12-14] . Lower rates
of seroma may be associated with the use of compression garments for at least 6 weeks in addition to the
[13]
use of closed-suction drains. Donor site dehiscence was reported in 1 study to be 10% . Contour deformity
[7]
was more frequently seen in the initial years following the introduction of this flap, up to 20% , particularly
[7]
due to the oblique orientation of the skin paddle . However, more recently, Zoccali et al. reported donor
[13]
[15]
site deformity to be about 9.7% . This was a retrospective review of 119 patients who had undergone SGAP
free flaps for breast reconstruction. The patients were grouped into four donor site classes (1: minimal tissue
availability; 2: insufficient tissue to achieve breast symmetry; 3: sufficient tissue for tension-free closure and
contralateral symmetry; 4: patient experienced massive weight loss). What they found was that patients in
class 3 were protected from donor site morbidity, which one might expect. While these results may not
seem novel, it is worth noting that breast reconstruction patients must be chosen carefully for their
candidacy for SGAP reconstruction.