Reconstructive Surgery & Anaplastology

Phalloplasty is a complex surgical task. Successful creation or restoration of the penis must meet certain cosmetic and functional thresholds. The ideal neophallus should be sensate, hairless, and similar in color to the surrounding skin. It should have an inconspicuous scar, maintain rigidity for sexual intercourse, and allow for micturition upon standing. A single-stage procedure with minimal donor-site morbidity is highly desirable, albeit the potential complications that may arise. Moreover, patient management should not only cover the surgery but also the psychosocial aspects of the treatment. Unfortunately, no single reconstructive method to date has successfully achieved all of these goals. Penile (re)construction may be required for a variety of reasons such as gender reassignment trauma, and cancer resection [1- 4]. Less common applications for phalloplasty include the following: congenital defects, infectious diseases, as well as other pathologies such as hidradenitis suppurativa and lichen sclerosis [5-8]. Older reconstructive methods were lengthy and multi-staged. However, as the field of plastic surgery has progressed over the last century, so have the reconstructive techniques for (re)construction of the phallus and urethra. The introduction of microsurgical free flaps, in particular, has made a tremendous impact on the options available for phalloplasty.

In this article we present the methods of phalloplasty and urethral (re)construction that have been developed in chronological order, starting from the initial reports in the literature to the most recent and commonly used techniques.

The first total penile reconstruction was described in 1936 by Bogoras [9], a Russian physician. He called this peniplastica totalis. He used abdominal wall to create a random pattern, tubed, pedicle flap and combined this with autologous rib cartilage graft to provide rigidity to the flap. This created the first penile reconstruction which could achieve successful coitus [10]. His technique required four stages, and did not create a competent neourethra or an aesthetically pleasing appearance. However, it was certainly innovative in nature. Reconstruction of the urethra within a flap remained a challenge until a decade later, in 1946, when Maltz [11] introduced a new step of inserting an outside-in tubular flap within the tubed abdominal pedicle graft. Gillies [12] improved and popularized this method by performing the first female-to-male reassignment procedure on British physician, Laurence Michael Dillon. Although this method involved [13] separate operative steps, it remained the standard technique for female-to-male gender reassignment over the next 40 years. Various fasciocutaneous and extended pedicle island flaps were also developed during this time. Nonetheless, they continued to have suboptimal functional and aesthetic results due to their significant limitations in sensory recovery primarily [10,13,14].

Throughout the 1970’s other innovations were introduced in the field of penile reconstruction. In 1971, Kaplan et al. [15] developed a method that provided sensation to the neophallus. Their method involved using a pedicled medial thigh flap, based on the femoral branches of the genitofemoral nerve, to create the penile shaft and a turned-in flap from the median raphe of the scrotum to construct the urethra. This technique was initially used for patients who underwent penile amputation due to penile cancer. In 1972, Orticochea [16], a Colombian physician, first used a pedicled tube flap involving the gracilis muscle to provide an erection in patients who required reconstruction secondary to trauma and/or surgical ablation. In addition, the obturator nerve, which supplies sensation to the inner aspect of the thigh, was included and allowed the neophallus to experience erogenous, thermal, pain, and tactile sensations. A neourethra was also created. Patients reported satisfactory results in sexual performance and were even able to achieve orgasm. Despite these benefits, this technique consisted of five stages and included complications such as urethral fistulas and stenosis in addition to muscle-related problems with the gracilis muscle.

That same year, Mc Gregor et al. [17] developed the groin flap which was later adapted by Puckett, et al. [18] in 1976 for penile reconstruction, including a Scott penile inflation device to produce an erection. Previously, silicone rubber rods, bone, or cartilage were used to provide penile rigidity, but were found to erode through the soft tissue, as the neophallus takes some time to become sensate (9- 12 months). Moreover, the constant rigidity served as a source of embarrassment to the patient [19] and led to the creation of the Scott prosthesis. Initially, the development of a constricting scar around the inflation cylinder in the penis posed a problem. However, this was easily resolved by instructing the patients to only partially inflate the cylinders and to massage the neophallus during the healing phase.

In 1978, Horton et al. [20] introduced the first single-stage total penile reconstruction using bilateral gracilis muscle flaps for the penile shaft and a full thickness skin graft for the urethra. In addition to successfully completing penile and urethral reconstruction with minimal morbidity, they also achieved aesthetically favorable results. Advances in microsurgery over the next decade led to the development of the first free flap phalloplasty in 1982 by Song et al. [21] Puckett et al. [22] also employed the free flap phalloplasty with a successful outcome in two of their patients, while the third required a staged procedure secondary to flap loss. In 1984, Chang et al. [23] were the first to report the tube-within-a-tube radial forearm free flap (RFFF). This flap provided soft, hairless forearm skin, with uniformly thin subcutaneous tissue and a long vascular pedicle. They used autologous rib cartilage to provide rigidity since they believed that acrylic or silicone implants were prone to erode through the soft tissue after several years. Seven of their patients had successful outcomes, while one patient developed a fistula near the urethral anastomosis that was later corrected.

In 1988, Biemer [24] improved upon the RFFP by introducing the radial forearm osteocutaneous flap which provides more rigidity to the neophallus. This is still one of the most widely used techniques for penile reconstruction today. Sadove et al. [25] later reported on the free sensate osteofasciocutaneous fibula flap in biological males with traumatic amputations as well as female-to-male transsexuals. This method offers intrinsic rigidity (due to the larger volume of bone), superior donor-site location, and sensation from the lateral sural cutaneous nerve, and a long vascular pedicle enabling an end-to-side anastomosis of the flap to the femoral artery. Interestingly, both types of patients reported the ability to achieve orgasm, yet sensation of the neophallus was only described in half the transsexuals. However, the authors claimed that little correlation could be made between extent of sensation and ability to reach orgasm. Furthermore, it has been reported to have high patient satisfaction since it is easier to hide the donor-site on the lower extremity than on the upper extremity [26]. Still, sensation of the flap is dependent solely on the superficial peroneal nerve.

At the start of the 21st century, Santanelli et al. [27] were the first to report the use of the islanded pedicled fasciae lata flap based on the lateral circumflex femoral artery. They performed this flap on five female-to-male transsexuals and suggested that this mode of reconstruction left a less conspicuous donor-site. Despite its small dimensions, it is a safe option and provides sensation.

In 2006, Felici et al. [28] reported a new phalloplasty technique using the free anterolateral thigh (ALT) flap. Proponents of this flap proposed that it often avoids the common complications and problems encountered with previous techniques. The authors showed promising results and found that the ALT flap was sensate and could easily incorporate an inflatable implant. The ALT flap also had very low donorsite morbidity and the scar was easily concealed. It is limited, however, by the anatomic variability of the perforator vessels. Also, the additional requirement of a skin graft to cover the thigh donor-site has made it unacceptable to many patients [10], particularly patients who are obese. Koshima et al. [29] described the bilateral superficial circumflex iliac artery perforator flaps as another alternative for penile reconstruction. Advantages of this technique include a single-stage procedure, minimal donor-site morbidity with a concealed donor-site scar, and the ability to create a long urethra of up to 22 cm in length without developing complications, such as fistulas and strictures. However, poor sensory recovery remains a disadvantage of the ALT flap.

In 2007, Perovic et al. [30] reported on the use of the latissimus dorsi free flap for phalloplasty in an effort to counter previous limitations encountered with other reconstructive forms. This flap is easily elevated and has a very long pedicle allowing for an easier and direct anastomosis. There is also minimal donor-site functional weakness and scarring. The authors reported an 80% patient satisfaction rate with no flap loss or partial skin necrosis. The latissimus dorsi free flap also provides sufficient length to create an adult sized penis size in prepubertal children optimizing results and ensuring a better psychosexual development [31]. In the same year, Wang et al. [32] and Yang et al. [33] reported the use of a free scapular skin flap for penile reconstruction, although this was first described in 1997 by Rohrich et al. [34] as a combined reconstruction with a latissimus dorsi free flap for penile and perineal reconstruction. Due to the scapula’s complex anatomical configuration, they preferred to use a penile implant to provide adequate rigidity. Both investigators achieved favorable aesthetic and functional results and considered this an ideal method of reconstruction [35].

Lee et al. [36] in 2008, described a single flap technique for total penile reconstruction using the pedicled ALT flap. The main advantage was that their method did not require microsurgery. Furthermore, this flap was shown to provide greater bulk and better skin color matching. The authors suggested that if the anterolateral thigh was too thick then the next best option would be to perform a RFFF. That same year, Lumen et al. [37] presented comparative results using the RFFF and the pedicled ALT flap for penile reconstruction. Their cohort consisted of 11 patients, seven of whom were treated with RFFF and four with a pedicled ALT flap due to contraindications to free flap creation (i.e. variable pelvic anatomy and vasculature) or patient preference. They found that sensitivity was markedly reduced with the ALT flap, which was expected since only one nerve innervates this area (lateral femoral cutaneous nerve). Today, the radial forearm free flap remains the most common form of phalloplasty. A search of the literature has demonstrated various experiences among different surgeons and institutions using a multitude of reconstructive techniques (Table 1). Our group recently performed a successful RFFF without bone on a 62 year-old African American male, with hypertension and type 2 diabetes, who was 8 months post-penectomy for penile squamous cell carcinoma. There were no post-operative complications or donorsite morbidity (Figure 1). This technique’s reliability for producing favorable aesthetic results, low donor-site morbidity, and outstanding erogenous sensitivity surpasses other means of reconstruction [38]. In cases where there are contraindications to free flap use or insufficient expertise and confidence, other available reconstructive methods [27- 29] can be employed.

Table 1: Phalloplasty Flaps and Associated Complications.

Figure 1: Radial Forearm Free Flap (RFFF) Reconstruction for Penile Cancer. (a) Status post penectomy for penile squamous cell carcinoma. (b) 7 months post-phalloplasty with RFFF. Patient is currently awaiting implant placement. (c) Donor site with healed skin graft.

The penis plays an important physiological role in both the genitourinary and reproductive systems. Due to its intricate anatomy and function, (re)construction poses a great challenge. In addition to creating or reconstructing a phallus that is aesthetically pleasing in shape and size, erogenously sensate, and sufficiently rigid to accomplish coitus, total penile (re)construction should also provide the patient with the ability to urinate through the urethra from a standing position [38-41].

Successful phalloplasty requires (re)construction of the pars pendulans and pars fixa [42]. Historically, there have been numerous attempts to recreate the urethra and reduce the high incidence of complications such as fistulas and strictures [42]. Urological complication rates in phallic (re)construction have been reported to be between 50% and 80% [24]. Table 2 displays the various complications associated with urethroplasty. As expected, efforts continue to improve upon existing surgical techniques. Since the creation or reconstruction of both the fixed portion and a movable portion of the penis is required with consideration of multiple angles of orientation, major problems inevitably arise. The ability to cover the urethral anastomosis with bulky, well-vascularized tissues is crucial for preventing fistula formation [25]. Furthermore, while some surgeons have developed combined or staged procedures for phallus and urethral (re)construction, others have also reported on their efforts solely to reconstruct the urethra [43,44]. Currently, the pars pendulans is commonly constructed via prelamination, which helps decrease the incidence of urethrocutaneous fistulas [10]. The RFFF is a commonly employed flap for urethral prelamination [38]. This flap offers a consistent, reliable vascular pedicle and pliable skin that permits shaping and flexibility for design [45]. We recently reconstructed a penis in a 24 year-old transgender male using a radial forearm osteocutaneous free flap with mucosal prelamination (Figure 2a). Stage I prelamination can be performed using a radial forearm flap with vaginal mucosa, buccal mucosa, and skin graft (if needed) for the neourethra (Figure 2b). However, use of this flap with sacrifice of a major artery to the hand has been associated with donorsite morbidity 2, [46-48]. Therefore, some authors have recommended using the ALT flap to avoid these complications [49]. Despite technical advances in microsurgery, urologic complications rates remain as high as 40%, as described by Hoebeke and Monstrey in a series of 287 patients [50]. Reconstructing the pars fixa is for lengthening purposes and, in turn, avoids further complications. For a successful phalloplasty, lengthening of the short female urethra is an essential step in order to perform an intact and secure anastomosis. Furthermore, many authors [51-53] suggest advancing the neourethra more anteriorly, which can be achieved by reconstruction of this portion [42]. Tables 3 and 4 display the multiple techniques and flap types used over time for (re) construction of the pars pendulans and pars fixa, respectively.

Table 2: Urethral Reconstruction for Phalloplasty and Associated Complications.

Figure 2: Female-to-Male Transgender Phalloplasty with Mucosal Prelamination, (a) 1 month post-operative image of transgendered male phallus reconstructed with prelaminated mucosa radial forearm osteocutaneous free flap, (b) Stage I prelamination utilizing fibula flap with proximal vaginal mucosa and skin graft for neourethral reconstruction.

Table 3: Pars Pendulans Urethral (Re)construction for Phalloplasty.

Table 4: Pars Fixa (Re)construction for Phalloplasty.

In 1982, Tank et al. [54] encountered eight cases of penile amputation and performed penile reconstruction in two children with satisfactory cosmetic and functional results. Over a decade later,Perovic [13] reported the use of the extended pedicle island groin flap for phalloplasty in children and adolescents. In 2006, Djordjevic et al. [31] described the use of the musculocutaneous latissimus dorsi free transfer flap for total phalloplasty in prepubertal children to prevent psychological trauma from body dysmporphia. The authors’ results demonstrated phallic sizes ranging from 13-16 cm in length, no flap necrosis, acceptable donor-site scarring and, importantly, an overall improvement of psychological well-being. Phalloplasty in the pediatric population presents is more challenging than in adults. The most accepted recommended time for (re)construction in the pediatric population is between 10 – 14 years of age 13. The inability for exponential growth of a pediatric reconstructed phallus or constructed neophallus (compared to testosterone-induced growth of a normal penis) and the psychological impact related to genital inadequacy are of highest concern. Common methods for phallus reconstruction, such as the fasciocutaneous forearm flap, are more likely to contract than muscle-based grafts. This is due to connective tissue being more prone to contraction compared to well-vascularized, denervated muscle [55]. Therefore, prepubertal phallus reconstruction must reflect an adult penis size to reduce the chances of genital inadequacy and subsequent psychological stress. All these factors should be discussed with both the parents and child prior to surgery. Although gender identity is considered to develop by 18 months old, construction of a neophallus is not commonly preformed in transgendered patients until the age of 18. However, in cases of amibiguous genitalia, the patient may have a female phenotype with a male genotype, and surgical construction to their genotype may be recommended [3].

Despite the great technical advances since the initial complete penile reconstruction was performed, reconstructive outcomes are still suboptimal. Phallic and urethral (re)construction require a multidisciplinary approach by the plastic reconstructive surgeon and urologist in order to achieve acceptable results. Currently, there is a lack of standard outcome measures to properly evaluate the most optimal reconstructive method. Previously reported results and outcomes have been based on a broad spectrum of patients often as little as one patient case reports and surgeon experience, thus making the reports even more subjective. Further, the complications have not been stratified according to severity. Important outcome measures for phalloplasty are erectile capacity and fistula occurrence. With microsurgical advances, flap transfer survival is no longer the most common challenge, but rather fistula occurrence.

Primary outcomes in transgender patients should be judged on assessment of their level of gender dysphoria. The Utrecht Gender Dysphoria Scale (UGDS) [56] and the Gender Identity/Gender Dysphoria Questionnaire for Adolescents and Adults (GIDYQ-AA) [57] are useful instruments in measuring gender dysphoria pre- and post-reconstruction. Although both tools evaluate gender dysphoria, differences exist between what aspects of gender dysphoria they assess. While the UGDS focuses more on physical aspects and gender role, the GIDYQ-AA emphasizes social and more subjective gender dysphoria issues. Therefore, future studies on phalloplasty outcomes should incorporate multiple scales to accurately encapsulate patient satisfaction and benefit. Secondary outcomes should include physical and sexual function as well as morbidity. Key complications include partial or total flap loss, anorgasmia, urethral fistulas, infections, and wound separations. Short-term studies can include outcome measures pre- and post-reconstruction, while long-term studies can assess patient outcomes post-reconstruction. Since patients can potentially undergo up to 6 surgeries within the first year after phalloplasty [58], it seems appropriate that the time points post-reconstruction should be monthly and either biannually or annually thereafter. Because penile reconstruction is oftentimes met with complications requiring multiple revisions, long-term studies may be more informative as they follow the patient over time. A thorough and multi-disciplinary preoperative evaluation is necessary before surgery to maximize outcomes. Studies may benefit from correlating pre-operative planning with postoperative outcomes, which will help guide surgeons’ decision making and to reduce poor outcomes.

Recent developments in tissue bioengineering [59] and stem cell therapy [60] may play a future role in improving upon previously used methods or may offer entirely novel techniques for modern phalloplasty. Early reports of penile transplantation, describing its feasibility, technical aspects, and outcomes have been made [61-63]. Nevertheless, ethical issues related to both the donor and recipients remain a concern [64]. Finally, the ultimate therapeutic success depends on the psychosocial aspects of treatment as well. As such, it is the duty of the reconstructive surgeon to use methods that will create an aesthetic and functional phallus and urethra while managing the expectations of their patients.

Conflicts of Interest Statement: None of the authors have any financial disclosures.