Fig. 3.1
The final result of a metoidioplasty. (a) The neourethra is advanced up to the tip of the clitoris’ glans. (b) The scrotum is created with the use of labia majora’s flaps, and the shaft is fashioned with the rotation of local skin flaps
Metoidioplasty, despite a high rate of complications such as fistulas and strictures, with up to 88 % of patients requiring revision surgery, is still considered by some authors the method of choice in a selected group of patients who are still in doubt about their need for phalloplasty (Hage and Van Turnhout 2003).
Patients who wish to engage in sexual intercourse cannot be served with a metoidioplasty and require total phallic construction.
3.4 Evolution of Phalloplasty Techniques
The development of total phallic construction techniques has paralleled the evolution of flap development in plastic surgery. At the moment more than 20 different types of flaps are available for phallic construction.
The first total phallic reconstruction was attempted in 1936 by Bogoraz, who used a random pedicled oblique abdominal tubularized flap with no incorporated neourethra to create a neophallus in patients who had previously experienced a traumatic amputation of the penis. A rib cartilage was incorporated in the flap to guarantee the rigidity necessary for penetrative sexual intercourse (Bogoras 1936).
Bogoraz’ technique was then improved by Gillies who fashioned a phallus with incorporated neourethra from a random pedicled abdominal flap using the ‘tube within a tube’ concept. This procedure involved a multistaged tissue transfer from the abdomen, resulted in extensive scarring and disfigurement of the donor area and produced a phallus without any tactile or erogenous sensation (Gillies and Harrison 1948).
The need for multistage tissue transfer has been overcome with the introduction of infraumbilical skin and groin flaps. Although the initial results were poor, as the phalluses obtained were non-sensate, wedge shaped and had no incorporated neourethra, the infraumbilical flap technique has been progressively refined, and now good cosmetic results can be achieved in more than 2/3 of patients (Fig. 3.2a–d). Moreover, patients who wish to be able to void while standing can be offered the creation of a neourethra made from a pedicled tube of labial skin or a free flap based on the radial artery, which is incorporated in the previously fashioned phallus (Bettocchi et al. 2004).
Fig. 3.2
The infraumbilical flap phalloplasty. (a) A 12 × 12 cm infraumbilical flap is raised. The dissection is carried out just above the rectus fascia. (b) The flap is tubularized to form a phallus. (c) The donor site defect is primary closed using abdominal flaps. (d) The final result at 3 months
The use of musculocutaneous thigh flaps based on the gracilis muscle should instead be discouraged as the muscle component tends to contract with time, leading to poor cosmetic and functional results (Persky et al. 1983).
The advent of microsurgical and free tissue transfer techniques has represented the beginning of a new era for total phallic reconstruction with Song and Chang describing in the early 1980s the use of the radial artery free flap (RAFF) for the creation of a neophallus in patients who had previously experienced a penile amputation (Chang and Hwang 1984; Song et al. 1982). This technique involved the creation of ‘a tube within a tube’ using a forearm skin flap with the urethra fashioned from the non-hair-bearing ulnar aspect and the whole flap based on the radial artery. This technique allowed the creation of a cosmetically acceptable phallus; sensation was also maintained due to the coaptation of the antebrachial nerves to the dorsal nerve of the clitoris or to the iliohypogastric and ilioinguinalis nerves.
Following the success of this series, many modifications in the flap design have been applied in order to improve the cosmesis of the neophallus and to minimize the overall complication rate, which can be as high as 45 %. Ulnar artery-based flaps have also been used to reduce the amount of hair-bearing skin incorporated (Gilbert et al. 1995).
The main drawback of forearm free flaps is donor site morbidity, which still represents a stigma and may be difficult to be accepted by patients. Therefore, free osteocutaneous fibular flaps, anterolateral thigh flaps and upper arm flaps have been used for total phallic construction, as they are associated with a less obvious donor site morbidity. However, due to the characteristics of the skin and subcutaneous tissues, using these flaps the neourethra cannot be fashioned with the tube within a tube technique. Therefore, in patients who wish to void while standing from the tip of the phallus, a prelaminated neourethra can be fashioned by tunnelling a skin graft or a mucosa graft inside the phallus (Rubino et al. 1993; Papadopulos et al. 2008).
An alternative in patients who wish to achieve cosmetic and functional results similar to the one provided by the RAFF phalloplasty but want to minimize the donor site morbidity is the incorporation of a 4 cm wide tubularized free forearm flap based on the radial artery in a pre-fashioned infraumbilical flap phalloplasty. In a recent series of 27 patients, this technique yielded excellent cosmetic and functional results, and all patients who have completed the two-staged procedure were able to void from the tip of the phallus and had acceptable donor site morbidity, as the flap was relatively small (Garaffa et al. 2010a) (Figs. 3.3a–e and 3.4).
Fig. 3.3
The radial artery-based free flap urethroplasty. (a) The 4 × 17 cm flap is designed on the relatively less hairy medial aspect of the forearm. (b) The free flap is raised under tourniquet compression. (c) The donor site is repaired with a full-thickness skin graft harvested from the abdomen or buttock. (d) The donor site 6 months postoperatively. (e) The neourethra is incorporated in the infraumbilical flap phalloplasty
Fig. 3.4
Latissimus dorsi flap
This chapter will concentrate on the radial artery-based forearm free flap phalloplasty since it is considered the technique that yields the best cosmetic and functional results.
3.5 The Radial Artery-Based Forearm Free Flap Phalloplasty
This procedure involves three stages, which are usually carried out at 4–6 months’ distance from each other, and the overall process takes at least 1 year. The first stage consists in the creation of the phallus, which is transposed to the recipient site, and the insertion of a testicular prosthesis in one of the labia majora. The second stage involves the anastomosis of the native to the phallic urethra and the sculpture of the glans, while during the last stage, the cylinder(s), pump and reservoir of an inflatable penile prosthesis are inserted to guarantee the rigidity necessary for penetrative sexual intercourse. The testicular prosthesis is removed and transferred in the contralateral labia, and the pump is inserted in the capsule that had previously formed around the testicular prosthesis.
3.5.1 Stage 1
The phallus is created from a forearm free flap that is raised from the nondominant arm; to minimize blood loss the procedure is performed under tourniquet compression of a maximum of 2 h of inflation time. The size of the flap varies according to the dimensions of the forearm and to patient’s expectations. The flap is separated longitudinally in two portions by a 1 cm wide strip of de-epithelialized dermis. The medial portion, obtained from the relatively hairless ulnar aspect of the forearm, is typically 4 × 15 cm and forms the neourethra, while the lateral portion, which is usually 15 cm long and has a width of 13–14 cm at the base and of 9 cm at the tip, will form the phallus. The flap is based on the radial artery, which is dissected to its origin from the brachial artery. The venous drainage is usually based on the cephalic vein, the venae comitantes of the radial artery and flap veins. Sensation of the flap is provided by the cutaneous nerves of the forearm (Fig. 3.5a, b).
Fig. 3.5
The radial artery-based free flap phalloplasty. (a) The free flap is formed by two aspects: the inner one is a 4 cm wide strip that will form the neourethra, while the outer one will form the phallus. (b) The blood supply is guaranteed by the radial artery, while the venous drainage is provided by the cephalic vein, comitantes and flap veins
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