September 16th, 2014
Both the transverse rectus abdominis musculocutaneous (TRAM) and the deep inferior epigastric artery perforator (DIEP) flaps utilize abdominal tissue to reconstruct the breast.
It is helpful to think of a TRAM flap as the first generation DIEP flap. In a TRAM flap, the lower abdominal skin is transported to the chest while remaining attached to the rectus or “6-pack” muscle. In this operation, the muscle is freed from its sheath and released from its attachments at the pubic bone. The muscle and skin can then be folded upwards and tunneled beneath the chest skin to provide tissues that can be used to reconstruct the breast. While the procedure is usually successful, there can be times that the blood supply may be inadequate and the tissue will fail. This stems from the fact that the rectus muscle has a blood supply that enters from both the top and from the bottom of the muscle. In a TRAM flap, the lower blood supply is divided to allow the tissues to be folded upwards. This then makes the tissues used to make the breast quite far from the origin of the blood vessels used to supply the flap which are left intact at its top. This anatomical arrangement can lead to the death of the tissues and loss of the flap. Additionally, the change in position of the muscle can lead to abdominal weakness and potential hernia formation. Most plastic surgeons have the skills necessary to perform this operation as the blood vessels that nourish these tissues remain intact.
The second generation represents a free TRAM. In this procedure, the skin of the lower abdomen is lifted using a portion of the rectus muscle and the lower blood supply to the muscle. This represents a personal transplant and the blood vessels are reattached under the microscope either in the chest or the armpit. This helps reduce problems associated with distant blood vessels and decreases the risks of partial or total flap death. Additionally, only a small portion of the muscle is used and the risks for abdominal weakness and hernia formation are reduced. Plastic surgeons who perform this procedure have additional expertise in breast reconstruction and many of them have completed additional training in microsurgery.
The final generation of the TRAM flap is the DIEP flap. In this procedure, the abdominal tissues are transplanted using the blood vessels alone. No muscle is taken during the operation and a goal is to preserve the nerves entering it so that it remains functional. This further reduces the problems of abdominal weakness and hernia formation. Plastic surgeons performing DIEP flap breast reconstruction have an even higher level of expertise and will often use similar principles for other types of reconstruction in their practice.
For more information about TRAM flaps, DIEP flaps, or breast reconstruction I invite you to schedule a consultation with either myself or my partner. Please feel free to contact our office at (972) 566-3939 if you have any questions.
-Brice W. McKane, M.D.