CHAPTER 39 Transverse Myocutaneous Gracilis With Vascularized Lymph Node Transfer
Breast reconstruction and simultaneous vascularized lymph node transfer can be done with a gracilis flap and its transverse skin island from the upper thigh.
A second vascular anastomosis may be necessary to the lymph node part of the flap.
The combination of free vascularized lymph node transfer (VLNT) with breast reconstruction seems to be the optimal treatment for a postmastectomy patient who has postoperative lymphedema of the upper extremity and wants breast reconstruction. Abdominal flaps (transverse rectus abdominis myocutaneous flap, deep inferior epigastric perforator [DIEP] flap, and superficial inguinal epigastric artery [SIEA] flap) are the benchmark for breast reconstruction, and inguinal lymph nodes can conveniently be included in these flaps.
However, not all mastectomy patients are candidates for abdominal flap transfer. Lower abdominal tissue volume may be inadequate because of slimness or body type, and multiple or midline scars from previous abdominal surgery can hinder the use of that area. Quite often even a slim young patient has a useful donor site in the upper thigh, and because of the inconspicuous placement of the scar, many patients prefer it over the donor site of the latissimus dorsi or thoracodorsal artery perforator flap in the back. In our institution we have offered the transverse upper gracilis flap since 2006 as one choice for breast reconstruction, patient anatomy permitting.
The use of the upper thigh as a donor site was first described by Yousif et al 1 in 1992, and the first suggestion for its use in breast reconstruction in the English-speaking literature was by Arnez et al 2 in 2002, who called it the transverse upper gracilis flap. Actually, Peek et al 3 in Germany had already described the use of the same skin island in breast reconstruction in 2002, but as a perforator-based flap. Schoeller et al 4 popularized this method and renamed the flap transverse myocutaneous gracilis (TMG).
In 2010 we performed the first combined TMG and VLNT on a patient with small A cup breasts in whom we could not use the lower abdomen as a donor site. Because we already performed DIEP and SIEA flaps with a VLNT routinely and obtained similar favorable outcomes as reported in the literature, it seemed natural to try to combine these procedures with another anatomically linked donor site. Because these patients have two problems, the lack of a breast and lymphedema, they seek help for both.
The TMG is planned as usual, but the drawing of the skin incision continues over the inguinal crease and either along the iliac spine linking the TMG flap to a groin flap or along the hairline and SIEA vessels.
The markings are first done with the patient standing, marking the lateral edge of the pubic hair line, the inguinal ligament, and the femoral vessels. As in any TMG flap, the width of the skin island in the thigh is determined by pinch grip, and the upper edge of the island is placed as high as possible. In the back, the midline of the buttocks and the lateral tip of the gluteal fold are marked, because the skin island should not exceed that point to stay invisible.
The patient is then placed in the supine position. The femoral vessels are palpated, and the SIEA and superficial circumflex iliac artery (SCIA) vessels are identified with pencil Doppler ultrasound and are marked on the skin. The skin island of the groin and superficial circumflex iliac perforator flaps is designed to extend at least 5 to 8 cm from the estimated position of the lymph nodes to serve as a deepithelialized bridge crossing the scarred axilla and also to allow the use of a monitoring skin island. The skin island is positioned according to the Doppler signal and can either be more vertical on the SIEA or more horizontal on the SCIA vessels.
Either a contralateral or an ipsilateral flap can be designed according to the surgeon’s preference. We usually use an ipsilateral flap for easier mobilization of the patient. With a gynecologic table, both sides are easy to harvest with a two-team approach: one team prepares the recipient site and releases the axillary scar at the same time the flap is harvested.
We prefer to start by raising the vascularized lymph node flap as described by Becker and Hidden, 5 Chen et al, 6 and Becker et al 7 (see ). The skin island is most easily raised from lateral to medial and superior to inferior. The lateral part of the skin island can be raised above Scarpa’s fascia as a superficial circumflex iliac perforator flap, but because the lymph nodes derive their vascularity from the actual source vessel, the surgeon should follow the vessels and work one’s way deeper at the level of the fascia and eventually below it to expose the femoral vessels and origin of the pedicle. This is an area of vast anatomic variability, and either the SIEA or the SCIA vessels can be used to carry the vascularized lymph nodes. The literature warns about going below the level of the inguinal ligament to avoid injuring the lymph drainage of the lower extremity 8 , 9 (see ). It is advisable, especially at the beginning of a surgeon’s experience, to use reversed mapping to monitor that all nodes draining the lower extremity are excluded. Patent blue injected to the distal tip of the flap may also be helpful.
The skin island of the groin and vascularized lymph node flap is designed to join the skin island of the TMG and should be kept as wide as the skin closure allows. As soon as the decision is made regarding which lymph nodes will be included in the flap, the dissection of the flap continues medially at a level immediately below Scarpa’s fascia until medial to the saphenous vessels (Fig. 39-1, A). The critical lymph vessels of the lower extremity usually lie below the inguinal ligament medial to the femoral vein and are not touched. The surgeon can again go deep to the level of the fascia and continue to raise the TMG flap as usual. We usually keep the pedicle of the lymph node flap connected, and it is divided only after the whole flap has been raised at the same time as the actual gracilis pedicle (Fig. 39-1, B).
The TMG is raised in a standard fashion, identifying the saphenous vein and dividing its branches to the skin island. The fat is raised at the level of the fascia over the adductor longus muscle, and blunt dissection of the loose areolar space between the adductor and gracilis reveals the pedicle. After the pedicle has been identified, it is easy to proceed distally along the gracilis muscle. This can usually be done bluntly, with the fingers distally, up to the tendinous insertion of the muscle. The secondary pedicle is clipped and divided. Posterior to the gracilis, the flap is raised in a suprafascial plane, tapering the subcutaneous tissue 2 to 5 cm below the distal skin edge to recruit as much volume as possible.
After the muscle has been divided and the posterior part of the flap released, the surgeon dissects the vascular pedicle, ligating and dividing the branches to the adductor longus and sharply dividing the motor nerve to the gracilis. If necessary, the proximal part of the pedicle can also be exposed from lateral to the adductor longus muscle.
Before the pedicle is divided, the surgeon should temporarily occlude the pedicle of the lymph node part of the flap to evaluate the vascularity of the nodes on the gracilis pedicle alone (Fig. 39-2). In our clinical experience the flap bled well in two out of three patients, and a second anastomosis was unnecessary. Perioperative indocyanine green angiography is a helpful aid in this decision-making.
As in any VLNT, meticulous release of the axillary scar is necessary, and a space is created along the axillary vein in the proximal arm. The tip of the deepithelialized skin island is placed in this pocket and temporarily fixed through the skin (Fig. 39-3). The nodes are placed along the axillary vessels and a breast is created (Fig. 39-4). When TMG is combined with vascularized lymph nodes, we prefer to use the thoracodorsal or circumflex scapular vessels as the recipient vessels. When the thoracodorsal vessels are divided at a level above the serratus branch, they can easily be transposed to the pectoralis margin and anastomosed to the gracilis pedicle without tension.
Because the scar at the donor site has a tendency to broaden, the surgeon should use some fixation sutures, such as in a medial thigh lift procedure. The skin is often closed with barbed sutures, and two suction drains are used—one in the thigh and one in the groin.