Tuesday, February 24, 2009

What is a TAP flap?

Pic #1: Flap Design on Chest
Pic #2: TAP flap elevated
Pic #3: Donor Site of Chest (note incision, no loss of muscle)
Pic #4: Donor Site on Back

The TAP flap is a new perforator flap that originates from the same blood vessels as the Latissimus muscle. TAP stands for Thoracodorsal Artery Perforator flap. Because of its location, it has a very nice donor site, underneath the arm pit area and back. It can be used in breast reconstruction as a local flap or free flap, giving a lot of versatility.

This flap is not as large as the abdominal tissue flaps from the DIEP, SIEA, or TRAM, but has good indications for smaller to midsize breast issues. Typically, a lumpectomy or partial mastectomy defect can leave a significant breast deformity. This flap can be "rotated" into the wound defect or deformity or microvascularly transplanted into the wound.

New treatment options for postmastectomy lymphedema

Lymphedema after a mastectomy is an extremely difficult problem. The mainstay of treatment has been lymphatic massage and physical therapy. Lymphedema usually progresses over time and the tissues become more and more recalcitrant to physical therapy and massage. Because of the inadequate lymphatic flow, tissue that is lymphedematous is more at risk for infections. This sets up the extremity into a downward spiral as the remaining lymphatic vessels are further destroyed by subsequent nfections. This then causes further lymphatic obstruction and edema and causes a worsening of the inflammation and scarring process, which leads to further fibrosis of the extremity.

The only true way to treat this condition is to restore the lymphatic flow where the obstruction is sitting. Previously, this has been done by lymphovenous bypass procedures. They have been only moderately successful. This requires extremely delicate microvascular anastomoses to reconnect lymphatics to the veins so that the lymphatics have a channel to leave the swollen extremity.

A more novel approach and more anatomically correct operation would be to replace the lymphatic channels with lymph tissue, and lymph nodes to help re-create new lymphatic channels. This can be accomplished by lymph node transplantation with a vascularized skin flap. This is a cutting-edge operation and the worldwide literature is quite sparse. The preliminary findings after this operation have been extremely promising. There has been a dramatic decrease in the number of infections as well as a significant increase and the diameter of the extremity after this surgery. These results are far better than the previous lymphovenous bypass surgeries and represents a new paradigm in treating extremely difficult lymphedema. This operation will likely serve as a more permanent solution to an extremely difficult and debilitating problem.

Use of the Internal Mammary Artery Perforator, No Rib Resection

The internal mammary artery has become the vessel of choice for microsurgical breast reconstruction. It has become popular because the position the of the vessel allows the flap to be positioned on the chest at a more medial position, versus the more lateral position of the lateral thoracic vessels. If you study the breast mound position, you will find that medial placement of the mound is more important than lateral placement.

The main issue with the use out of this vessel are twofold. #1. It requires removal of rib cartilage and deeper dissection into the thoracic cavity to gain access to this vessel. This sometimes leaves an indentation on the chest wall where the rib was removed. #2. The left internal mammary artery is a common source vessel for coronary artery bypass surgery to revascularize the heart. This means that in some rare cases, if this vessel has been used for breast reconstruction, it is no longer available for heart bypass surgery.

It is our philosophy that we should try to avoid use of this vessel when possible. We have been able to find, in a majority of our cases, the perforating artery and vein to the internal mammary vessel. This has shortened our operating time as well as avoiding the issues discussed above with removable are written and use of the main source vessel for coronary artery bypass surgery. We have been able to identify this vessel with ultrasound techniques as well with finesse, microsurgical dissection.

What is a DIEP Flap?

DIEP stands for the Deep Inferior Epigastric Perforator flap. This block of tissue is based upon the main blood vessel which supplies vessels to the rectus abdominis muscle. This flap has become popular for breast reconstruction as the block of tissue that is transplanted to reconstruct the breast is the same tissue that is removed for a "tummy tuck." The main advantage of this procedure is that it leaves the muscle mainly intact and only uses the tissue that is required for the reconstruction, mainly the skin and fat. In this procedure, extremely fine and delicate dissection is performed to preserve the very small blood vessels which connect the skin and fat through the muscle, then finally to the main blood vessel --the deep inferior epigastric artery and vein, which then connects to the external iliac artery.

Shown above is a DIEP flap that was harvested for a recent breast reconstruction case. The 3 photos show the Flap still connected to the rectus muscle, and then the flap detached and ready for transplantation. (Surgeons- Drs. C. Lee and S. Hansen, San Francisco)