SIEA Flap, TRAM Free Flap
With advances in microsurgery over the last decade, there are several new procedures that are being widely sought after by women. While the pedicled TRAM flap is still the standard of care in the United States, some surgeons have expertise in advanced microsurgical techniques, which provide women with more elegant, optimal solutions when utilizing abdominal tissue. These options allow for achieving better aesthetic results with fewer donor site complications. Nevertheless, these are longer procedures with potential for other complications such as total flap loss. The success rate in transferring tissue in this manner is very high in the hands of surgeons who perform microsurgery regularly, in institutions with experience monitoring these flaps. However, if blood vessel thrombosis (clotting) occurs in the transplanted flap, urgent re-operation is required for flap salvage, or total flap loss will result. Before proceeding, the patient should ask the microsurgeon as to their volume of experience, and their overall rate of success.
DIEP Flap Reconstruction
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The deep inferior epigastric perforator (DIEP) flap is based on the deep inferior epigastric vessels, an artery and vein at the bottom of the rectus abdominis muscle. These vessels provide the primary blood supply to the skin and fat of the lower abdomen. In the DIEP flap, the lower abdominal skin and fat is removed without having to harvest any of the rectus abdominis muscle. Instead, blood supply is provided through the perforator vessels that are teased out from the rectus muscle, using a muscle incision alone. The surgeon will apply judgment in the operating room to determine how many perforators are needed to provide sufficient blood supply for the DIEP flap to survive.
Once the DIEP flap is raised, a microscope is used to transplant the tissue to a recipient set of blood vessels on the chest wall. The tissue is used to create a breast shape without having to be tunneled under the skin (as in the pedicled TRAM flap).
In order to avoid using any muscle, it will take longer to harvest a DIEP flap than a TRAM flap. However, this results in the advantage of minimizing injury to the abdominal wall muscle, resulting in less pain, and a lower risk of hernia formation as compared with TRAM flaps.
SIEA Free Flap Reconstruction
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An alternative free flap that utilizes the skin and fat of the lower abdomen is the superficial inferior epigastric artery (SIEA) flap. The SIEA flap involves no incision through the abdominal muscle because it does not utilize the deep inferior epigastric vessels. In an SIEA flap, incisions are made in the skin and fat only, allowing the flap to be transferred based on the superficial inferior epigastric vessels. This allows for even less post-operative pain, and no risk for hernia.
As with the DIEP flap, the SIEA flap is first harvested and then transplanted to the chest wall where a microscope is used to attach the flap vessels to a recipient set of blood vessels on the chest wall. The tissue is then used to create a breast shape.
Unfortunately, only a minority of patients are candidates for the SIEA flap because the superficial vessels are very small, limiting flap volume, and increasing the risk of flap loss. In some patients, these vessels may not be present because of previous surgery such as Caesarean-section or hysterectomy.
TRAM Free Flap
TRAM Free Flap Reconstruction
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The TRAM free flap is similar to the DIEP flap in that this type of flap is also based on the deep inferior epigastric vessels. In the TRAM free flap, the lower abdominal skin and fat is removed along with a small portion of the rectus muscle. The portion of muscle removed carries these blood vessels with the flap.
Using a microscope, the TRAM free flap can then be transplanted to a recipient set of blood vessels on the chest wall. As with the DIEP or SIEA flaps, the tissue is used to create a breast shape without having to be tunneled under the skin (as in the pedicled TRAM flap).
The advantages of this surgery as compared to a pedicled TRAM flap are two-fold. First, only a small amount of the rectus muscle is used, with less post-operative pain and less risk of abdominal bulge or hernia. Second, the blood flow to the skin and fat is much greater than that of the pedicled TRAM flap. This allows more abdominal tissue to be safely transferred, and patients who are not optimal candidates for the pedicled TRAM flap (diabetics, smokers) can usually be accommodated.
The disadvantage of the TRAM free flap is that the small amount of muscle used is still more than in the DIEP and SIEA flap approaches where no muscle is utilized. As such, compared to DIEP and SIEA flaps, the risk of abdominal wall weakness is slightly higher when the TRAM free flap is utilized.
Choosing the Abdominal Free Flap
In planning breast reconstruction with abdominal microvascular free flaps, the surgeon should explain the risks and limitations of these approaches. Ultimately, the final choice of free flap depends on the patient’s anatomy. In the course of surgery, the superficial vessels used for an SIEA flap are first encountered. If these vessels are adequate in size and could support the needed flap volume, an SIEA flap may be performed without incising or harvesting any muscle. Otherwise, the perforators from the deep system are exposed in order to elevate a DIEP flap. If these perforator vessels are sufficient, then the DIEP flap is completed. If the perforator vessels are found to be inadequate, the operation could then be converted to a free TRAM flap.
The length of surgery for abdominal microvascular free flaps can range from five to seven hours for one breast, and seven to twelve hours for both breasts. The hospital stay is typically three to five days, and the recovery can take several weeks before returning to a regular activity level. Secondary procedures after free flap breast reconstruction can be done after about three months; however, if chemotherapy is needed, any additional surgery must await completion of treatment. At that point, the patient can have revisions to the breasts and abdomen, and the nipple areola can be reconstructed. Such additional procedures are typically done as outpatient surgery with a rapid recovery.
You are an ideal candidate for abdominal microvascular free flap breast reconstruction if you:
- desire autogeneous reconstruction, and want to minimize muscle loss
- do not want or are not a candidate for implant reconstruction
- have enough lower abdominal wall tissue to create one or both breasts
- have compromised tissue at the mastectomy site
- have been previously radiated
- have had failed implant reconstruction
- are having immediate reconstruction at the time of skin-sparing mastectomy
- are having delayed reconstruction following prior mastectomy
- desire reconstruction to fix a lumpectomy or quadrantectomy defect
You are not an ideal candidate for abdominal microvascular free flap breast reconstruction if you:
- do not have enough lower abdominal tissue to create the flaps
- have had previous abdominal surgical procedures such as abdominoplasty (a C-section scar is usually okay)
- cannot tolerate anesthesia for long periods
- do not wish to have a lower abdominal scar
You may refer to the Post-Operative Abdominal Flap section to learn about care after abdominal free flap breast reconstruction.
Please go to our Personal Stories section to see before and after photos.