Recently the Deep Inferior Epigastric artery Perforator (DIEP) flap has become a successful and popluar choice for breast reconstruction due to it’s limited abdominal wall without any disruption of the abdominal wall fascia. While the DIEP flap reliably perfuses the skin and fat across midline, the limits of the SIEA flap perfusion is not well documented.

Purpose

To delineate the extent of cutaneous and adipose tissue perfusion of the SIEA. Specific concern focuses on the extent of contralateral lower abdominal skin and the thickness of adipose tissue perfusion.

Materials and Methods

IRB approval was obtained to complete methylene blue injection studies of the SIEA on abdominoplasty specimens. Ten patients underwent elective abdominoplasties. Each abdominoplasty flap had a single SIEA cannulated with a 25 gauge angiocath. Injection of methylene blue was then done until staining of the skin and fat reached a plateau.. Areas of blue staining were evaluated.

Results

In all cases the perfusion of the ipsilateral abdominal wall skin and fat , above and below Scarpa’s fascia was complete. In no cases was there complete perfusion beyond what would be zone IV of a TRAM. While 7 cases showed skin and superficial fat ( above Scarpa’s fascia ) perfusion in what would be zone II of a TRAM, in only 2 specimens was the fat below scarpa’s fascia also perfused.

Conclusions

Breast reconstruction has advanced significantly with the use of the DIEP flap due to its limited abdominal wall morbidity. The SIEA Flap is a further advance as there is no fascial disruption. While SIEA flap lowers the abdominal wall morbidity, it should be limited to ipsilateral lower abdominal wall skin and fat. Aterial perfusion of the skin extends across midline but the fat below Scarpa’s fascia is not reliably perfused on the contralateral hemi-abdomen. By extending the flap further across midline we risk increasing the extent of fat necrosis in the reconstructed breast.