DIEP (deep inferior epigastric perforator flap)

New Advances in Breast Reconstruction: Moving Towards Better Outcomes
By Drs. Michael W. Neumeister and Nicole Sommer

In 1982, Carl Hartramp revolutionized breast reconstruction with a popularization of the transverse rectus abdominis myocutaneous flap (TRAM flap). This flap uses redundant tissue in the lower abdomen to reconstruct breasts following mastectomies for breast cancer.

The TRAM flap offered a number of advantages over other techniques of breast reconstruction. Specifically,the TRAM flap is only autogenous tissue with no need for breast implants. This means that the appearance and texture of the breast are considerably more natural. The donor scars are well concealed on the lower abdomen, permitting normal swimsuit wear, as well as other clothes. This donor scars typically lie in the suprapubic region from the iliac crest on one side, to that on the other. The latissimus dorsi flap from the back, uses autogenous tissue is well, but does not offer enough tissue to be utilized alone, and therefore an implant is often required to obtain appropriate breast size. The donor site scar in the back is not easily hidden in swimwear.

The TRAM flap is not without its own downsides. In fact, there may be considerable morbidity associated with the TRAM flap. First of all, the flap is harvested with the entire rectus abdominis muscle; a muscle that contributes to the overall function and strength of the abdominal wall. Many patients complain of weakness of the abdominal wall when trying to sit up after having the TRAM flap reconstruction. Even worse are those cases where both rectus abdominis muscles have been harvested for bilateral breast reconstruction. In these cases, the abdominal wall may be weakened as much as 60% from its original strength. Another point should be made about the TRAM flap. The vascularity of the TRAM flap is based on its nondominant blood supply: the superior epigastric artery. The main blood supply of the tissue in the lower of normal wall is based on the deep inferior epigastric artery. Because the pedicled TRAM flap is based on its secondary blood supply, the tissue is prone to fat necrosis. This means that the amount of tissue that can be harvested with a pedicled TRAM may be significantly limited. This may compromise the overall result of the breast reconstruction. Fat necrosis compromises the overall shape and appearance of the flap and may result in significant wound break down.

In an attempt to improve upon the morbidity of the TRAM flap, recent modifications have been made. One modification is to harvest lower abdominal tissue on its primary blood supply: the deep inferior epigastric artery. To harvest the lower abdominal tissue on this blood supply, the flap must be taken as a free tissue transfer. This free flap mandates microsurgical techniques to anastomose the donor vessels to recipient vessels on the anterior or lateral chest wall. Typically, the two most utilized recipient vessels are the internal mammary artery and vein medially, or the thoracodorsal artery and vein laterally. This flap, called a free TRAM flap, offers the benefits of less fat necrosis and limited muscle resection. A small segment of muscle must be resected with a free TRAM.

Although the free TRAM is not as prone to fat necrosis as the pedicled TRAM, the resection of a small amount of muscle can also weaken the abdominal wall. The latest advancement in breast reconstruction takes advantage of the primary blood supply of the lower abdominal tissue yet preserves the rectus abdominis muscle to prevent weakness of the abdominal wall.

The DIEP flap (deep inferior epigastric perforator flap) is based on the perforating vessels from the deep inferior epigastric artery and vein as they course through the rectus abdominis muscle to supply the overlying fat and skin. Meticulous dissection of the perforators through the muscle preserves the integrity of the muscle. The DIEP flap was introduced in the 1990’s as a means of preserving the muscle of the abdominal wall. This new flap offers all the advantages of the free TRAM without the obliteration of the abdominal wall musculature.

A very long pedicle can be harvested to permit optimal positioning and contouring of the lower abdominal tissue for breast reconstruction. Many times the anastomosis is performed to the internal mammary artery and vein or perforators of these vessels between the ribs. The advancement of the DIEP perforator flaps, takes breast reconstruction to higher-level. Indeed, perforator flaps are utilized in head and neck, lower extremity, and upper extremity reconstruction presently. Breast reconstruction utilizing the primary blood supply of the lower abdominal skin and fat offers abundant tissue, less fat necrosis, and a better contour and natural texture to the breast following mastectomies. The DIEP flap can be performed immediately at the time of the mastectomy or in a delayed surgery following chemotherapy or radiation treatments. The management of patients with breast cancer continues to be improved upon and techniques such as the DIEP flap are an example of our passion to provide optimal care for these patients.

For more information, contact the Institute for Plastic Surgery at 217-545-8000.