DIEP Flap Breast Reconstruction

No muscle or overlying muscle fascia is used in DIEP breast reconstructions.  The DIEP flap relies on blood vessels that travel through (perforate) the rectus abdominus muscle to supply the overlying abdominal skin.  The vessels that supply the perforator circulation to the DIEP flap are the deep inferior epigastric artery and the deep inferior epigastric vein.  By dissecting the perforators originating on these vessels from the skin and through the surrounding muscle to their origin, the rectus abdominus muscles are preserved and the rectus fascia is preserved.  This is in contrast to the TRAM flap where rectus muscle is lost from the abdomen along with the overlying rectus fascia. The DIEP flap can be used for immediate or delayed reconstruction. 

THE ABDOMEN IN CROSS SECTION

This figure below depicts the abdominal muscles in cross section and the perforating vessels that travel through them to supply circulation to the skin. The TRAM flap relies on circulation supplied to the skin by the muscles and the perforators.  In the DIEP flap, no muscle is taken, but the muscle is dissected and preserved.

THE UNDERSURFACE AND VASCULARITY OF THE DIEP FLAP

To the right, a DIEP flap has been dissected free, and has been retracted to show it's inferior surface together with the deep inferior epigastric artery and vein and four perforating branches to the flap.  The perforating branches have blue backgrounds under them.  The clamp can be seen on the rectus sheeth fascia, and the muscle is seen medial to this.

DIEP DESIGN IN BREAST RECONSTRUCTION

In the diagram below the flap is pictured outlined in red, and the paired rectus muscles with their inflow deep inferior epigastric artery (red) and vein (blue) are illustrated.  For purposes of clarity, only one vessel is depicted for each muscle. The flap can be split in half (bottom right) to reconstruct two breasts if a bilateral breast reconstruction is needed.  It need not be split in half if more soft tissue is required for a single sided reconstruction.  In that case, the edges of the flap are discarded to shape the breast.

THE DIEP IS HARVESTED AND TRANSPLANTED TO THE CHEST

The abdominal tissue to be used to reconstruct the breast is illustrated in yellow below.  The edges of the flap are discarded (purple), as are the portions most distant from the inflow and outflow circulation.  On the right, the flap has been brought into the mastectomy field and the blood vessels must be microsurgically repaired to branches from the internal mammary artery and vein.  The thoracoacromial system can be used to supply inflow in some cases, particularly the descending pectoral branches.  The abdominal wound is closed (bottom right) and the umbilicus is reconstructed over the now tighter abdominal skin.

CIRCULATION IS RE-ESTABLISHED

Below, the flap is tailored to make it as symmetrical as possible with the other breast.  A scar from the incision required for the mastectomy, sometimes extended medially or laterally for vessel exposure, is present.  A portion of rib cartilage is removed and the circulation to the flap is reestablished using the internal mammary artery and vein.  The reconstructed breast is shaped and placed in the mastecomy skin pocket.  A variable amount of abdominal skin is visible on the reconstructed breast depending on the native breast skin.  The nipple areola reconstruction is usually scheduled for a later date, when all tissue has healed.  Secondary revision surgery may be required on the breast at a later date to approve appearance or symmetry.  The rectus muscles are preserved althoght they have been dissected to harvest the DEIP flap.  The rectus fascia is closed over them before closing the abdomen and fashioning a new umbilicus.