68. Penile Reconstruction after Trauma and in Gender Dysphoria

Marco Falcone¹ and Giulio Garaffa²

(1)

Urology Clinic, Molinette Hospital, Città della Salute e della Scienza, University of Turin, Turin, Italy

(2)

The Institute of Urology, Westmoreland Hospital, University College of London Hospital, London, UK

Marco Falcone

Email: marco.falcone@unito.it

Keywords

PhalloplastyTotal phallic reconstructionGender dysphoriaTranssexualismPenile traumaPenile amputation

68.1 Historical Considerations

Due to the unique anatomy of the male genitalia and to the lack of tissue that may adequately replace the smooth muscle of the cavernosal bodies and the spongiosum, total phallic reconstruction (TPR) still represents a real challenge for the reconstructive surgeon.

The main goals of a TPR are the creation of a cosmetically acceptable phallus with both tactile and erogenous sensation. Ideally, the phallus should have an incorporated neourethra, to allow the patient to void and ejaculate from the tip of the neoglans and adequate bulk to allow the insertion of an internal stiffener to guarantee the rigidity necessary to successfully engage in penetrative sexual intercourse.

The first historical attempts aiming to reconstruct a phallus were based on abdominal flaps. The first TPR was described in 1936 by Nikolaj Bogoras, a Russian surgeon, who used a random pedicled oblique abdominal flap . He achieved phallic rigidity inserting a cartilage rib inside the flap [1].

Subsequently, Matz and Gillies, imported the idea to incorporate a neo-urethra in the phallus in a “tube within a tube ” fashion in the attempt to restore both urinary and ejaculatory functions [2]. However, these procedures had several limitations. Indeed, they required multiple procedures, they resulted in extensive scarring and disfigurement of the donor area, as the phallus was progressively transferred in stages to the recipient site, and last but not the least they lead to the creation of a non-sensitive phallus. Therefore, to date, these techniques should be considered only as salvage procedures after a failed phalloplasty.

Infraumbilical and groin skin flaps have the advantage of requiring a limited number of surgical stages and of causing an acceptable donor site morbidity but produce a non-sensitive wedge-shaped phallus [3–5].

Gracilis miocutaneous flaps have been abandoned due to poor cosmetic results, as the muscle tends to scar down and contract [6].

In the 80’s, the advent of microsurgical techniques and their application in reconstructive surgery revolutioned the concept of TPR, as they allowed to transfer tissue as free flaps in a single stage even when donor and recipient site were distantly located. In 1982, Song and Chang were the first Authors to describe the use of radial artery based free flap (RAFF) for phallic reconstruction in a series of patients that had suffered traumatic amputation of the penis [7]. The reconstructive procedure involved the creation of a phallus according to the ‘ tube within a tube ’ concept using a fascio-cutaneous flap usually harvested from the non-dominant forearm. The neo-urethra was usually fashioned from the less-hairy medial aspect of the flap. The vascular supply of the flap was based on the radial artery, on the “venae comitantes” of the radial artery and on 1 to 2 main veins. Tactile and herogenous sensations were both guaranteed by the anastomosis between the antebrachial nerves and the dorsal nerve of the penis and the ileo-inguinal nerve.

After the initial cases described by Song and Chang, many other Authors have introduced personal modifications in flap design in order to improve the cosmesis of the neophallus and to minimize the incidence of complications and the donor site morbidity [8–10].

Also, an ulnar artery-based variant of this flap has been described, aiming to reduce the amount of hair bearing skin incorporated in the neourethra, as the medial aspect of the forearm tends to be less hairy than its lateral counterpart [11, 12].

Up to date, the main types of phalloplasty available are:

1.

The radial artery phalloplasty (RAP) , which is performed as a free flap
2.

The infraubilical phalloplasty also known as pubic phalloplasty (PP) , which is performed as pedicled
3.

The anterolateral thigh flap (ALT) , which can be performed either as a pedicled or as a free flap
4.

The latissimus dorsi flap (LD) , which is performed as a free flap

1.

The radial artery forearm free flap phalloplasty (RAP)

Although it does not represent the ideal technique, the RAP is so far considered the gold standard technique as it guarantees superior cosmetic and functional results compared to the other techniques available. Indeed, it allows the formation of a cosmetically acceptable sensate neophallus with an incorporated neourethra, which reaches the tip of the neoglans. Various Authors have demonstrated that this technique represents a valuable option in patients following penile amputation for carcinoma or trauma, in patients with penile inadequacy and in female to male sex reassignment surgery [8, 13–15].

Despite the main limitation of this approach which is represented by the visible scar at the level of the donor site on the non-dominant forearm, representing stigma in these patients, functional limitations and sensory changes are rare, as confirmed by multiple large series published in the literature [9, 16, 17].

Surgery is performed only after the competency of the superficial and deep palmar arteries has been tested with an Allen test . Duplex sonography is reserved to these patients who had a negative or inconclusive test. Laser or electrolysis-based hair removal from the forearm can represent a valuable tool to improve the cosmesis and minimize hair growth in the neourethra, which may lead to stone formation, recurrent urinary tract infections and voiding dysfunction.

Typically, the TPR with a modified radial artery based free flap is carried out in the following three stages, which are carried out at an average of 6 months’ intervals to guarantee a complete scar maturation:

1.

Creation of the neophallus with competent neourethra and transfer to the recipient site as a free flap with microsurgical technique.
2.

Sculpture of the glans and creation of a pseudo-corona according to the Norfolk technique with the use of a full thickness skin graft to fashion the ridge and the groove of the neoglans. This stage is meant to render the cosmetic aspect of the phallus more realistic.
3.

Insertion of an artificial stiffener , ideally a penile prosthesis into the neophallus to guarantee the rigidity necessary to engage in penetrative sexual intercourse in patients keen to be sexually active. Inflatable penile prosthesis are less associated with pressure sores than their semirigid counterpart and, therefore, they represent the preferred option.

Although the RAP is far from being an ideal technique, penile reconstruction with this approach has proven superior to all other techniques since it:

1.

Guarantees a superior cosmetic result by forming a cylindrical phallus rather than the wedge shaped one that is obtained using infra umbilical and groin flaps .
2.

Allows the creation of a neourethra that reaches the tip of the phallus, which is significantly less prone to complications than skin graft urethroplasty. Urethral complications with other types of phalloplasties are extremely common and require multiple revisions. This is the main advantage of this technique when compared to the latissimus dorsi flap , where the only way to fashion a neo-urethra is with a prelaminated buccal mucosa graft applied directly on the muscular portion of the flap and is tubularized over a stent 4–6 months afterwards
3.

Allows the creation of a sensate phallus whereas in other phalloplasties the sensation is minimal (anterolateral thigh flap and latissimus dorsi flap) or absent (Gillies flap and distal 2/3 of infraumbilical flap).

Donor site morbidity can be dramatically reduced by adequate preparation of the donor site for grafting. This involves adequate hemostasis and the advancement of the edges of the intact forearm skin to reduce the area that requires grafting and to minimize the step between normal skin and the grafted muscle. With regards to the type of skin graft, thick grafts have proven to be superior to thin grafts as they heal with less scarring and discoloration [17, 18]. Alternatively, excellent results can be achieved with the interposition of a porous matrix of cross-linked bovine tendon collagen between the recipient bed and a split thickness skin graft in order to recreate the appearance of a subcutaneous tissue.

In the past, bone and cartilage grafts have been widely used and incorporated in the neophallus in the attempt to guarantee the rigidity necessary to engage in penetrative sexual intercourse. Currently, the best results in terms of rigidity, capacity to conceal and reliability are achieved with the insertion of an inflatable penile prosthesis [19–21].

2.

Infraumbilical (pubic) phalloplasty (PP)

This technique, most commonly used for TPR in female to male transsexuals [22], can be modified for use in traumatic amputation patients, although no published data is available for this group. The advantages of this technique are that it is easily reproducible, does not require microsurgical skills and the operating time is relatively short. Additionally, another advantage of this technique is that the donor site scarring is limited to the abdomen, which is easily concealable when compared to the forearm or the thigh. The main drawbacks of this technique are the creation of a wedge shaped, hairy phallus, which lacks a neourethra and is insensate for the distal two thirds of its length.

The phallus is fashioned from a cutaneous flap that is raised from the inferior aspect of the abdominal wall (Fig. 68.1). Usually the dimensions of the flap are 12 cm in width and 12–14 cm in length, which is measured from the base of the pubis. Where possible, the superficial external pudendal vessels are incorporated into the base of the pedicle. The anterior abdominal wall skin is then dissected off the rectus fascia and mobilized caudally to enable a primary closure of the donor site defect avoiding the need for skin grafting.

../images/468369_1_En_68_Chapter/468369_1_En_68_Fig1_HTML.jpg — Fig. 68.1

Design of a suprapubic pedicled phalloplasty

The subsequent steps of glans sculpture and prosthetics are similar to the ones previously described for the RAFF . Since urethral complications associated with a staged skin graft urethroplasty are high in terms of contracture and fistula formation, patients can be offered a delayed incorporation of a radial artery based neourethra into the neophallus (radial artery urethroplasty). The procedure, involves the microsurgical transfer of a radial artery based 4 cm wide flap harvested from the inner aspect of the non-dominant forearm. Once tubularized around a stent, the flap is fitted in a previously fashioned pubic phalloplasty. In expert hands, this procedure is associated with low complication rates, in terms of stricture and fistula formations and it is not prone to sacculation [23].

3.

Antero-lateral thigh flap phalloplasty (ALT)

The ALT flap is a reasonable option in patients requiring a TPR [24, 25]. This is a fascio-cutaneous flap based on the perforator vessels through the vastus lateralis and rectus femoris from the descending branch of the anterior circumflex femoral artery. The ALT flap is very reliable from a vascular point of view and is commonly used in reconstructive surgery. For total phallic reconstruction purposes, a 16 × 16 cm (16 × 20 cm if incorporating a neo-urethra) flap needs to be raised. The dissection is more difficult compared to the radial forearm flap because the perforator vessels need to be released from the surrounding fiber of the rectus muscle in around 85% of cases. Frequently there is a pedicle long enough to reach the pubic area after the tunneling of the flap under the rectus femoris tendon, which then obviates the need of any microsurgical vascular anastomosis. However, the main drawbacks of the ALT flap are the presence of a thick subcutaneous layer and the presence of a conspicuous amount of hair. These characteristics render simultaneous neo-urethral construction using the “tube within tube” technique difficult. Often the phalloplasty is made from the ALT flap and the neo-urethra is then formed from a 4 cm wide radial forearm flap, with a principle similar to the one previously described for infraumbilical phalloplasty and radial artery urethroplasty [23]. There is only one cutaneous nerve within the ALT flap so the potential sensation is not as good as in case of radial artery phalloplasty. Careful patient selection is therefore particularly important to achieve good cosmetic results. Because of the large size of the donor site defect, a split skin graft is used to cover the donor site. Although donor site scarring tends to be poor, the area can be easily hidden even if the patient is wearing short trousers.

4.

Latissimus dorsi flap (LD)

The latissimus dorsi flap represents another valid alternative for total penile reconstruction [26]. It is a myocutaneous flap based on the thoracodorsal artery, which is a descending branch of the subscapular artery.

Usually a large skin flap, up to 15 cm wide and 20 cm long can be raised on a 3–4 cm strip of latissimus dorsi muscle, as there are many reliable perforators around the anterior intramuscular branch. This technique allows the creation of a sensate phallus, as the thoracodorsal nerve, which runs alongside the thoracodorsal artery and vein, guarantees the innervation of the flap.

The main advantage of LD flap phalloplasty is the limited donor site morbidity as the defect can be primarily repaired without the use of a skin graft and with minimal scarring. However, the TPR requires forcedly multiple stages. The first is phallus formation with microsurgical tissue transfer techniques to the recipient area. At this stage, the neophallus does not contain a neo-urethra as the flap is too thick to allow the creation of a neourethra with a “tube within a tube” concept. A “prelaminated” urethra can therefore be fashioned in two stages using buccal mucosa grafts, which are applied on the muscular strip of the flap. Using this technique urethral strictures and fistulae are common. Penile prosthesis implantation is performed using the same technique described for the RAP once sensation has resumed and flap/urethral complications dealt with.

68.2 Penile Amputation Following Trauma

Although genital injuries in civilian centers are not frequent, the scenario is completely different in the battlefield, where the use of protective torso armour, to protect the abdomen, has led to the survival of patients with extremely severe injuries to the genitalia and lower limbs caused by fragmentation weapons. On the contrary, the most common cause of genital trauma in civilians are self-amputation after an acute psychotic episode, road traffic accidents, gunshot or blast wound, Fournier’s gangrene and sexual assault. In case of avulsion injury, the penis can be adequately preserved in sterile ice sluice for up to 24 hours and a microsurgical reimplantation can be successfully attempted within this time frame. If the penis is not adequate for primary reimplantation or it cannot be found, then delayed penile reconstruction needs to be considered [13].

68.3 Penile Trauma Classification

The Rashid and Sarwar [27] classification is commonly used to describe penile traumatic amputations:

Type I – The most proximal part of the corporal stump and of the urethra are present and palpable; the urinary meatus reaches the tips of the corporal stump; the scrotum and the testicles are preserved.
Type II – The pendulous corpora cavernosa are absent. The crura are preserved and the urethra is transected at the level of the pubic symphysis; the scrotal skin is partially lost.
Type III – The corpora are totally absent; the patient voids through a perineal urethrostomy.
Type IV – The corpora are t otally absent and the urinary meatus is not visible in the perineal region. The patient voids through a urinary diversion (often a suprapubic catheter).