The forearm flap can be elevated and transferred on the superficial fascia. The lateral and medial antebrachial cutaneous nerves appear proximally beneath the fascia. The cephalic, basilic and medial antebrachial veins are also included in the flap and constitute a portion of the venous drainage (Fig. 28.2).

The shaft is covered with the radial aspect of the skin paddle. A deepithelialized strip is made, and a second skin island, on the ulnar aspect of the skin paddle, is tubed to form the urethra. The urethral tube is then rolled within the tube of skin to form a tube-within-tube design, around a 16-F catheter (Fig. 28.3).

T-shaped radial forearm free flap that retains the lateral antebrachial nerve is raised and transferred. The reconstructed penile vascular pedicle is divided and the transplantation is completed by vascular anastomosis by serrated sutures. The vascular pedicle of the reconstructed penis is tunnelled into the inguinal region subcutaneously. The vascular anastomosis of the cephalic vein or its branches and the radial artery to the superficial epigastric artery or the femoral artery (previously prepared and tunnelled into the inguinal region) is carried out under operating microscopes (Fig. 28.4). The anastomosis may be either end to end or end to side as the case necessitates. Cutaneous nerves in the proximal shaft aspect of the flap are coapted to the clitoral nerves.

If the neo-urethra is created, the construction of the fixed part of the urethra up to the level of the clitoris is accomplished using an anterior vaginal flap. The vaginal mucosa is initially separated posteriorly; the anterior wall of the vagina is preserved while the rest of vaginal mucosa is removed. This mucosa is rolled up to provide extension of urethra to the base of the clitoris. The labia minora are then sutured in the midline and the urethra is closed over for healing phalloplasty. Extension of the urethra to the base of the clitoris with the anterior vaginal mucosa has greatly reduced fistula formation. Colpocleisis also better supports the vascularity of this area, providing a well-vascularized anastomosis site for neo-urethra creation. Subsequently, a neo-glans is modelled, as shown in Fig. 28.5. In the final step, urethral anastomosis is completed. A urethral catheter is inserted during this procedure (Fig. 28.6). That will be removed 3 weeks after surgery and the defect on the donor arm site is covered with a full-thickness skin graft harvested from the upper thigh (Figs. 28.7 and 28.8); harvest from the buttock or the abdomen is described. A compressive dressing is applied to the graft and the arm kept elevated for 1 week. The arm is then inspected every week thereafter. Figure 28.9 shows the final results after a 3-month follow-up.

In literature, the use of an osteocutaneous free flap is reported [17]. In these cases, a piece of radial bone, based on the diaphyseal periosteal branches of the radial artery, approximately 10 cm in length and not more than one-third of the thickness of the radius, was harvested with the flap.

Due to the complex nature of the operation, complications are numerous and should be explained in detail to the patient: in experienced hands, partial or total flap loss should be expected in less than 5 % of the cases, and nerve compression or compartment syndromes due to the prolonged lithotomy position in less than 2 %. Urethral complications such as fistula and/or stenosis formation still are the leading reasons for reinterventions in around 50–60 % of all patients.

Traditionally local flaps without the need for microsurgical vascular anastomoses were seen to be less prone for complications than free flaps. From recent publications of experienced high-volume centres, it becomes obvious that the more complex the primary procedure is designed, the more possible complications are implicated independently from the surgical technique [18, 19]. In 2005, Monstrey et al. demonstrated on 81 patients with phalloplasty derived from forearm free flaps a 3.6 % rate of partial or total flap loss, 22 % of wound healing problems and 42 % of urinary fistulas or stenosis.

Another recent paper from Leriche et al. dealt with the follow-up of 56 patients after forearm free flap phalloplasty. A 5 % flap loss rate was reported, 37 % had urethral complications, and 29 % had prostatic complications [19].

Even if reinterventions for urethral problems may be successful, nearly half of the patients report urinary problems as reduced urinary stream, dribbling or recidivant urinary infections [20].

Possible complications after free flap phalloplasty comprise early and late anastomotic revisions due to venous, arterial or combined thromboses, partial or total flap loss and urological complications such as fistulas and strictures, which frequently require multiple urological revisions.

Urethral fistulas and strictures are the two main problems arising in patients with total phallic reconstruction; in particular, one-stage procedure seems to be associated with a higher risk of urinary complications. Reasons may be the insufficient vascular supply of the local flaps and the inappropriate width of the phallic urethra, the latter being responsible for relative obstruction of the urinary stream and increased force on the ‘bulbar urethra’ and anastomotic sites.

In the series of Biemer [8], the neo-urethra was constructed from a 3-cm-wide skin strip. In 9 of 10 patients evaluated after an average of 30 months, urethral fistulas were observed. In 7 of these patients, 3–4 reoperations did not solve the problem; moreover, in 4 patients urethral strictures were present as well. Rohrman et al. reported a casistic with 25 cases with primary female transsexualism underwent phalloplasty with a radial forearm free flap, vaginectomy and urethroplasty in a one-stage procedure. In 16 of these patients, the fixed part of the neo-urethra (‘bulbar urethra’) was constructed from a vaginal flap. In 9 patients, flaps of the labia minora (5 patients) or the ‘urethral plate’ (4 patients) were used. In 14 (58 %) patients, fistulas and/or strictures in the newly constructed urethra occurred. Eleven (69 %) of 16 patients in whom the ‘bulbar urethra’ was constructed from a vaginal flap experienced fistulas and/or stricture formation. Fistulas and/or strictures occurred in 3 of 5 patients with labia minora flaps and none of 4 patients with the urethral plate procedure. Repair of fistula and strictures was performed by primary closure of fistulas, staged urethroplasty with local pedicled flaps or distant tissue grafts using buccal mucosa (2–6 procedures) [21].

Partial flap necrosis is reported to occur in 7–11 % of phalloplasty cases [22, 23]. The largest series published by Doornaert et al. showed a rate of 7.2 % (23 out of 316 cases) with a higher incidence in smokers, in patients who insisted on large-sized neo-phalluses and after anastomotic revision. In 15 out of these 23 patients (63 %), debridement and secondary closure or skin grafting was necessary. 2 Partial flap necrosis frequently affects the radial and ulnar flap borders, which are both directly involved in the formation of the neo-urethra in the Chang design. This may lead to a necrotic or exposed neo-urethra and consequently to urethral dysfunction. Possible contributing factors to partial flap necrosis in a tube-within-tube setting are the flap width and the need for double bending of the flap. Additionally, postoperative flap swelling may cause venous congestion.

Baumeister et al. reported a series with 135 radial forearm flaps, in which 10 flaps had a thrombosis (3 arterial, 4 venous, 3 combined) on postoperative day 0, 1 (n = 5), 4, 4, 5 and 24. Six revisions were successful; 4 flaps failed (3 %). Twelve flaps (9 %) showed a partial or superficial necrosis which required an operative revision [22].

In case of partial flap necrosis with involvement of neo-urethra in toto, some authors suggested a salvage procedure with a second RFF from the contralateral side providing well-vascularized tissue. No flap-related complications were observed [24].

In case of thrombosis of arterial pedicle which results in ischemia of neophallus, some authors reported the perfusion of the flap with streptokinase which restored venous return. Flap perfusion was thereafter confirmed by intraoperative direct angiography of the neophallus [25].

Another important issue is morbidity on donor site after forearm free flap phalloplasty. In fact, despite continuous improvements in the technique of preparing the donor site for grafting that have allowed a significant improvement of the final cosmetic result, the residual scar on the donor arm still represents a ‘stigma’. Unaesthetic scarring, reduced bone density, limited range of motion, decreased pinch and grip strength or graft loss, delayed healing and sensory changes have all been reported after a radial forearm flap [26–30].