The deep inferior epigastric perforator (DIEP) flap is a revolutionary technique in breast reconstruction. This type of reconstruction uses tissue from the lower abdomen to reconstruct the breast. This "perforator" flap uses skin and fat from the abdomen attached to the major blood vessels, while sparing the underlying rectus muscle. The flap is then transferred to the mastectomy site and the blood vessels are reconnected with a microscope to complete the reconstruction. The abdomen is closed just as in a "tummy tuck" with recontouring of the abdomen.

This is significantly different from the traditional TRAM flap which sacrifices the entire rectus muscle in the reconstruction. Loss of the rectus muscle can result in significant abdominal weakness and hernia formation that impairs exercise and daily activity. In patients who undergo DIEP flap reconstruction, recovery is faster than a TRAM flap resulting in an earlier return to exercise and activity. There is also a lower risk of hernias and abdominal weakness. Patients also have less pain after surgery in a DIEP flap when compared to a TRAM flap.

In about 15% of patients the lower abdominal tissue is supplied by the superficial inferior epigastric artery (SIEA). These blood vessels travel under the surface of the skin and do not enter the rectus muscle. In these patients the skin and fat from the abdomen can be harvested without dissecting through muscle. The reconstruction otherwise proceeds in the same way as a DIEP flap as blood vessels are reconnected at the mastectomy site.

After surgery, patients typically stay in the hospital 3 days.