Radiological anatomy of the perforators of the gluteal region: The "radiosome" based anatomy.

Background: The superior (SGA) and the inferior gluteal artery (IGA) perforator flaps are widely used in pressure-sore repair and in breast reconstruction. The aim was to exhaustively depict the topographical anatomy of the whole system of perforators in the buttock.

Methods: Eighty lower-extremity computed tomographic angiography (CTA) of patients (20 males/20 females, mean age 61-years old, range 38-81) were considered. The source artery, location, type, and caliber of gluteal perforators were analyzed. The location of perforators was reproduced using a standardized two-dimensional grid on the coronal plane, centered onto defined bone landmarks. We defined "radiosome" the cutaneous vascular territory of a source artery inferred through the representation of its whole perforator system at the exit point through the deep fascia.

Results: A mean number of 25.6 ± 5.7 perforators in the gluteal region was observed, distributed as follows: 11.6 ± 4.8(45.2%) from SGA; 7.9 ± 4.5(30.8%) from IGA; 1.5 ± 0.8(5.8%) from fifth lumbar artery; 1.2 ± 0.8(4.7%) from internal pudendal artery; 1.2 ± 1(4.8%) from lateral circumflex femoral artery; 0.3 ± 0.7(1.2%) from circumflex iliac superficial artery. At least one large (internal diameter > 1 mm) SGA septocutaneous perforator was present in 77.5% of patients.

Conclusions: The gluteal region is vascularized by perforators of multiple source arteries. Septocutaneous perforators of SGA and IGA were planned along a curve drawn from the posterior-superior border of the iliac crest to the greater trochanter. The lumbar artery perforators are clustered over the apex of the iliac crest; the internal pudendal artery perforators are clustered medially to the ischiatic tuberosity. Contributions can also come from the sacral and superficial circumflex iliac arteries.