Breast Reconstruction Surgery - San Francisco California

Breast Reconstruction with the DIEP and Other Microvascular Flaps by Gabriel Kind, MD

Dr. Gabriel Kind
San Francisco Plastic Surgeon
www.sanfranciscodiep.com

Breast reconstruction with autogenous tissue has many advantages. The creation of a more naturally appearing breast with the patient's own tissues avoids the use of implants, and when the lower abdominal wall provides the tissue for reconstruction, an improvement in the appearance of the donor site can be achieved. Donor site selection is usually based on the tissue requirement at the recipient site. Several different donor sites have been described for breast reconstruction. By far the most common is the lower abdominal wall. Transverse rectus abdominis myocutaneous (TRAM) flaps were introduced into clinical practice in the 1980's and quickly gained popularity among patients and physicians.

"TRAM" is an acronym for "transverse rectus abdominis myocutaneous", and refers to the transverse orientation of the skin and fat taken from the lower abdomen, supplied by blood vessels that come through the rectus abdominis muscle. A "pedicled" TRAM flap uses skin and fat of the lower abdomen, which is elevated with the underlying rectus abdominis muscle, and rotated to the chest. The skin and fat are supplied by the "pedicle" of muscle, which carries and protects the blood vessels.

By the late 1980's, the advantages of the microsurgical ("free") TRAM flap were recognized, and as microsurgery became more widespread clinically, the free TRAM became a more common procedure. A free TRAM has several advantages compared to a pedicled TRAM. The flap is supplied by the same perforators as the pedicled TRAM, but the perforators are harvested with a much smaller portion of muscle, and get their blood supply from the deep inferior epigastric vessels, which is a much more direct blood supply. Because of this, the free TRAM flap has a more robust blood supply, so more tissue can be safely transferred. Better blood supply also means that free TRAM flaps have a lower incidence of fat necrosis than pedicled TRAM flaps, and can be used with greater confidence in high-risk patients, such as those who have undergone radiation. In addition, only a part of the muscle is used, which results in less damage to the abdominal wall, and a faster return to normal activities.

Lower abdominal wall flaps were some of the first microsurgical flaps to be described. The deep inferior epigastric system was recognized as a potential source, and muscle-sparing flaps using deep inferior epigastric perforators were reported as early as 1979. It was not until the 1990's that this flap was described in breast reconstruction. The increasing popularity of the deep inferior epigastric perforator (DIEP) and superficial inferior epigastric artery (SIEA) flaps has been due to many factors.

These flaps share the advantages that all of the lower abdominal flaps have in common (the lower abdominal wall typically provides adequate tissue for breast reconstruction; the donor site scar is usually well hidden; and for many patients, the sacrifice of the lower abdomen results in an aesthetic enhancement), but also have the additional advantage that abdominal wall muscles and nerves are spared, leading to decreased postoperative pain, shorter hospital stay and faster recovery from surgery. The timing of this flap's introduction coincided with the early growth of the internet, which has played a major role in disseminating information regarding microvascular breast reconstruction. Patients who previously would have accepted the options presented to them are now actively seeking information on the internet, and self-referring to receive the treatment of their choice.

In many patients the abdominal wall is unable to be used for breast reconstruction, either because of previous surgery or because the patient has an insufficient amount of subcutaneous fat in that location. In such patients, the search for other autogenous donor sites leads quickly to the lower body, particularly the gluteal areas and the medial and lateral thighs.

Gluteal flaps were initially described as musculocutaneous flaps, which incorporated a portion of the gluteus maximus muscle; more recently these flaps have been described as perforator flaps based on either the superior or inferior gluteal arteries. Flap harvest must be performed in the prone or lateral decubitus position, adding significant complexity to cases requiring bilateral flap harvest. The incisions are well hidden in clothing, but can be quite obvious otherwise. In some cases unilateral harvest creates a noticeable contour deformity and/or asymmetry.

The tensor fascia lata (TFL) musculocutaneous flap has been used frequently as a rotational flap to reconstruct areas around the hip, buttock, and lower abdominal wall. It was also one of the first flaps to be described as a free flap, and the musculocutaneous flap has been described for breast reconstruction. More recently, this flap has been harvested as a perforator flap. The perforator flap leaves a smaller contour deformity than the musculocutaneous flap, although the scar is arguably more readily visible than that created following gluteal flap harvest. Surgeons have used the TFL perforator flap for breast reconstruction, but found suitable perforators in only 50% (one of two flaps).

The gracilis muscle was initially described as a pedicled muscle flap in 1975. Its use as a microvascular flap has a rich history, both as a small muscle used to cover smaller wounds and as a functional muscle for facial reanimation and extremity motor reconstruction. Yousif et al described the use of the gracilis muscle with a transverse skin paddle for various defects, including a case of breast reconstruction, in 1992. More recently, Wechselberger et al and Arnez et al have reported their favorable experience with this procedure for breast reconstruction. Wechselberger described the flap design as "nearly identical to the preoperative markings of a classic medial thigh lift surgery".

In patients with a favorable ratio of medial thigh tissue to desired breast volume, the gracilis myocutaneous flap has several advantages. The flap dissection is straightforward and relatively rapid. Flap vessel length is adequate, particularly if the dissection of the vessels extends to their origin. The flap can be harvested with the patient in the supine position. The donor site scar is well hidden. The contour deformity created at the donor site is usually minor and considered favorable by most patients. From a functional standpoint, the loss of the gracilis muscle is not noticeable by even the most active patients.

The medial thigh subcutaneous fat can be safely dissected overlying the gracilis muscle through either a longitudinal or transverse incision. Surgeons favor the longitudinal incision for several reasons. In more than seventy-five procedures using the longitudinal incision to harvest the gracilis muscle for microvascular procedures, some surgeons have experienced no significant wound or scar complications. The proximal end of the longitudinal incision is several centimeters distal to the pubic bone, thus positioning the healing wound and eventual scar away from the perineum. There is little or no chance of scar contracture causing discomfort or distortion of the labia, which has been reported following medial thigh lift incisions.

Designing the flap longitudinally eliminates the need for complex closure techniques to avoid scar widening. The longitudinal flap design results in a scar on the posterior aspect of the medial thigh, which keeps the scar well hidden. general experience provides that the longitudinally-oriented flap provides as much tissue bulk as a flap oriented in the horizontal position, without creating a significant contour deformity. By designing the skin island to be directly over the muscle belly, reliable skin island blood supply extends to at least 50% of the length of the medial thigh, which is more than enough skin for most breast reconstruction cases.