transverse rectus abdominis musculocutaneous flap

Transplantation of a transverse rectus abdominis myocutaneous (TRAM) flap is a commonly used surgical procedure for breast reconstruction following mastectomy.

An autologous myocutaneous flap consisting of abdominal skin, subcutaneous fat, the rectus abdominis muscle, and adjoining vasculature is used for reconstruction of the breast following mastectomy.

The rectus abdominis muscle has a dual blood supply, which includes the superior and inferior epigastric vessels. The blood supply via the superior epigastric artery is less robust than its inferior counterpart.

Radiographic features

CT

The shape of the TRAM flap is the same as that of the native breast. However, fat-attenuation is predominant within the TRAM flap at CT, as opposed to the irregular soft-tissue attenuation of fibroglandular tissue mixed with fat seen in the native breast.

In general, there are three appearances of a TRAM flap:

• homogeneous fat attenuation
• fat attenuation with a thin, curvilinear soft-tissue band parallel to the skin surface
• thick soft-tissue band parallel to the skin surface

Within the flap, there tends to be areas of soft-tissue and fat-attenuation:

• the thin, curvilinear band of soft-tissue within the reconstructed breast represents the de-epithelialized skin from the abdominal wall
• the more superficial band of fat-attenuation tissue represents adipose tissue of the native chest wall
• the deeper rim fat-attenuation tissue represents the adipose tissue transposed from the abdominal wall.

MRI

In general, MRI appearances are the same as CT.

Replacement of the normal glandular tissue of the breast with lower abdominal fat and the presence of atrophied rectus abdominis muscle along the anterior chest wall.

Differential diagnosis

On imaging consider

• DIEP reconstruction: absence of atrophied rectus abdominis muscle and its vascular pedicle in the reconstructed breast differentiates a DIEP from a TRAM flap .