The Transverse Upper Gracilis flap (TUG) or inner thigh flap is a myocutaneous flap.It is supplied by the medial circumflex femoral artery, arising from the profunda femoris. This autologous reconstruction can be considered in patients that do not have adequate skin and tissue in the abdomen, or have had previous abdominal surgeries that may have jeopardised the blood supply to the DIEP flap.The ideal patient for the TUG flap is someone with small breasts who does not require a significant amount of volume for the reconstruction.
This technique offers autologous tissue reconstruction with good aesthetic results. The flap harvesting is relatively quicker with minimal donor site morbidity. Immediate nipple reconstruction is possible which not have aesthetic advantage, but also psychological. The main disadvantages to this flap is the short pedicle which might limit the anastomosis site options and also the vessels are of smaller caliper when compared to the DIEP flap. Also the volume of the flap is small, which is usually enough for a small to moderate size breast, but also there is loss of volume of the muscle component of the flap with time.
There are only very few contraindications in our unit, relative contraindications include smoking, diabetes, a raised BMI and significant co-morbidities. Discretion should be exercised in patients with significant co-morbidities that are planned for, or likely to require adjuvant chemotherapy or radiotherapy.
Further of these refinements can be found in the the videos to follow, they include, skewing of the flap posteriorly, preservation of the great saphenous vein, dissection superficial to the inguinal nodal tissue, muscle harvesting with the investing fascia.
The gracilis muscle is an expendable adductor of the thigh. It arises by a thin aponeurosis from the anterior margins of the lower half of the pubic symphysis and the upper half of the pubic arch. The muscle runs vertically downwards and inserts into the supero-medial aspect of the tibia.
The vascular supply to the muscle is from the medial circumflex femoral artery. This arises from the profunda femoris , approximately ten centimetres below the ischium. The artery is between 1 and 2 millimeters in diameter and pedicle length is approximately 6cm. The artery is accompanied by two venae comitans. The muscle is supplied by a branch from the obturator nerve.
This is done preoperatively with the patient initially lying supine, the leg is placed in the abducted or “frog-leg” position. The adductor longus is readily palpated. The gracilis muscle lies approximately two finger breadths posterior to the adductor. The crescent shaped flap is centered over the gracilis muscle. The superior skin paddle marking extends from a point just medial to the mid-point of the anterior thigh, and ends at the mid-point of the posterior thigh, within the gluteal crease almost to the ischial tuberosity. Although tempting to place the line within the groin crease itself, this should be avoided and the line should be placed 2 to 3cm below this crease. The skin paddle can be up to 25cm long while the pinch test is used to decide the width. We do not raise the paddle beyond 8cm in width as we feel that donor site morbidity increases markedly beyond this.
The Surgeon usually stands on the side of the flap to be raised. Usually we start with the inferior incision opening the fat and superficial facial recruiting the fat below the membraneous layer of the superficial facia to increase the flap volume. The skin paddle is outlined and dissection begins laterally. Using monopolar diathermy the most lateral aspect of the flap is incised down to scarpas fascia. No deeper as this will result in the surgeon needlessly carrying out a superficial inguinal lymphadenectomy. Staying in the plane just deep to the scarpas fascia, dissection proceeds medially until the long saphenous vein is encountered. This should be preserved. At the medial border of the vein, the plane of dissection switches and moves straight down onto and through the deep fascia of the adductor longus. At this point a finger can be used to gently sweep the adductor from the gracilis. Careful lateral retraction of the adductor allows easy identification of the gracilis pedicle, along with its nerve.
Having now clearly identified the gracilis and its pedicle, the remaining medial dissection can continue in the plane deep to the deep fascia that overlies the muscles of the posterior thigh (semimembranosus and semitendinosus) and the remaining skin paddle flap can be elevated up to the gracilis. At this point the muscle is transected inferiorly and superiorly, thereby releasing the flap from its surrounding by all but its pedicle.Pedicle length is approximately 6cm. The pedicle can be dissected up to the profunda femoris either solely from deep to the adductor longus and or over the lateral border of the adductor in order to get to its origin with the profunda. Meticulous haemostasis during the inferior transection of the gracilis is essential as once divided the distal end of the muscle retracts beyond reach. We find that infiltrating the muscle at the point of transection with 1% lidocaine helps to minimise muscular contraction during division, making it safer, easier and negating the need to administer systemic paralysis.
The crescenteric shape of the TUG flap allows it to be easily shaped by coning, giving it good projection and a rounded appearance. The defined summit of the coned breast provides a fantastic platform for nipple reconstruction.
The anastomosis is possible to the internal mammary artery (IMA) perforators especially the second and third perforators. The volume of the reconstruction can be increased either by using an implant or expander, or by using bilateral flaps one anastomosed in the axilla and the other on the IMA perforators or some wound lipofill the flap. The shorter pedicle of the TUG flap necessitates recipient vessels to be in close proximity. Our preference is therefore to use the second or third intercostal perforators from the internal mammary vessels or the main vessels themselves. See section on anastomosis.
The donor site is closed with 2.0 vicryl to the scarpas layer and a 3.0 V-Loc suture over a drain.
Patients are nursed in a high dependency unit in accordance with our unit’s protocol. The patient lays flat with one pillow under her head. No pressure is applied to the anastomosis site. The flap is monitored 1/2 hourly for 4hours on return to the ward, then 1 hourly. If the flap or the patient feels cool, or the patients temperature is below 36 apply the warm touch. 1 hourly observations are carried out and the donor site is also monitored (upper leg) hourly for signs of bleeding/swelling taking care not to abduct the donor site. For DVT prophylaxis, sub-cutaneous clexane is given in the abdomen as prescribed along with TED stockings & flowtrons. Antibiotics are given in the first few days postoperatively.