The simplest way of finding the most constant perforator (within a circle of 3 cm of midpoint of the line drawn between the anterior superior iliac spine and the superolateral corner of the patella [26]) is by handheld Doppler device (see Fig. 27.4). Color flow Doppler and CT angiography have greater sensitivity and specificity in localizing perforators, but they are time consuming and expensive.

Once the perforator has been identified, the design of the flap has to be transferred to the skin of the thigh. The flap base starts 1–2 cm proximal to the point where the perforator enters into the flap, and the flap is centered over the intermuscular septum between the rectus femoris and the vastus lateralis muscles (see Fig. 27.4). The design of the flap is different when the neo-phallus will have no urethra from the design of total phallic reconstruction.

The flap design is incorporated into an elliptical form for easier wound closure (see Fig. 27.4). First, the anterior incision of the flap is made along the anterior part of the predesigned ellipse through skin, subcutaneous fat, and fascia. Care is taken to preserve some 5 cm of the lateral femoral cutaneous nerve which will be later used to provide sensitivity.

The fascia is elevated by the single hooks, and the dissection proceeds in the posterior direction toward the intermuscular septum between the rectus femoris and the vastus lateralis muscles. The more the septum is being approached, the more care must be taken about any perforators piercing the rectus muscle which are preserved. Then the posterior incision is made, again through skin, fat, and fascia, and the septum is being approached taking care to preserve any perforator through the vastus lateralis muscle. The septum is opened, and the descending branch of the lateral circumflex femoral artery (LCFA) is identified lying on the vastus intermedius muscle between the rectus femoris and vastus lateralis muscles. As soon as it becomes evident that the major perforator from the LCFA is either septocutaneous or musculocutaneous perforating the vastus lateralis muscle, all anterior perforators perforating the rectus muscle are safely divided. The selected perforator is then dissected to the source vessel (LCFA). When the perforator pierces the vastus lateralis muscle, the pedicle dissection may be time consuming since multiple muscle branches have to be carefully identified and divided by bipolar coagulation or micro-clips to preserve the muscle.

Then the descending branch of LCF vessels (artery and vein) is divided from the motor nerve (preserving it) starting distal to the entrance of the perforator. Distal to that point, the vessels are ligated and divided and the dissection proceeds proximally. To be able to liberate the descending branch, multiple artery and vein branches are clipped or ligated.

The dissection stops at the level where the perforator through the tensor fasciae latae muscle to the skin takes off. At that point the flap is passed posterior to the rectus femoris and sartorius muscles from the lateral to the medial part of the thigh (Fig. 27.5).

The pedicle length should be such to permit tension-free reaching of the midline just cranial to the clitoris where the neo-phallus should be positioned. If the pedicle is too short, further pedicle dissection is necessary which can reach as far as to the profunda femoris vessels. To be able to do that, first the TFL perforator and later the ascending branch of the LCFA have to be ligated and divided.

After the optimal pedicle length is ascertained, the elliptical flap is trimmed to the preoperative design discarding all unnecessary tissue. This is followed by tubulization: the flap is sutured into a tube (or a “tube within a tube” in case the urethra is being reconstructed), passed under the rectus muscle, and delivered to the recipient site.

There the lateral cutaneous nerve of the thigh is trimmed to the necessary length and coapted by microsutures to the dorsal clitoris branch of the pudendal nerve to provide sensation. The neourethral tube is sutured to the urethral prolongation made from vascularized labial flaps over a Foley catheter. The cranial portion of subcutis at 12 h is fixed to pubic symphysis and the wounds are closed.

It is our experience to leave scrotal sac reconstruction, insertion of testicular prostheses, and penile prosthesis insertion for the second phase of the operation.

Donor defect is closed after generous undermining of the anterior and posterior skin and the subcutaneous fat dorsal to the fascia, and when possible, direct wound closure is carried out. Otherwise, positioning of the dermal substitute (Integra) and split-thickness skin grafting after 2–3 weeks are required.