Microsurgical Gender Affirmation Surgery

Abstract

Phalloplasty in the female to male transgender patient is a complex operation aimed at creating a functional and aesthetic phallus, external genitalia, and perineum. Functional goals include standing micturition and sexual function with erogenous and tactile sensation as well as the ability to participate in penetrative intercourse. Functional genital reconstruction relies on creating of a fully lengthened urethra from local tissues as well as the provision for additional length via tissue transplantation. This manuscript will review techniques for the creation of perineal urethral segment as well as primary flaps available for the creation of neophallus. Particular emphasis is given to our preferred method of reconstruction: single-stage urethral lengthening with radial forearm flap phalloplasty including a review of surgical techniques and complications.

While gender surgery has been practiced in various forms for decades, phalloplasty demand has drastically increased during the most recent 10 years. The reasons for this burgeoning interest are multifactorial including increased social awareness, insurance coverage, and recognition of gender affirmation surgery as beneficial to patient well-being. In addition, there are more willing surgeons with the appropriate skill set necessary to take on these challenging reconstructive cases.

The goals of phalloplasty are both aesthetic and functional. From an aesthetic perspective, the phallus must have a natural appearance with respect to size and contour while minimizing donor site deformity. The functional goals are two-fold: urologic and sexual. Urologic function relies on successful creation of a lengthened urethra that is free of strictures and fistulas. Sexual function relies on creation of a phallus, with both tactile and erogenous sensation, capable of penetrative intercourse.

To achieve these goals, the tissue used in creation of the phallus must be thin and pliable with a robust vascular network and a dedicated sensory nerve supply. A host of donor sites have been proposed and employed; however, there are only two that subserve each of these goals. As such, in our practice, we have limited phalloplasty to radial forearm (RF) and anterolateral thigh (ALT) donor sites.

Historical Background

Over the course of past 100 years, phalloplasty has evolved from the earliest described techniques employing tubed abdominal flaps, to what is now the gold standard tube within a tube free RF flap. Nicolaj Bogoraz performed the first penis reconstruction reported in the medical literature in 1936. ¹ His technique utilized a tube abdominal flap with an autologous rib graft for structural support. At that time, no provision was made for urethral reconstruction.

The first documented phalloplasty performed on a transgender patient was executed by Sir Harold Gillies in 1945. ² A series of 13 operations were performed on British physician Laurence Michael Dillon to transform Dillon's natal female genitalia to a male equivalent. Gillies utilized two separate abdominal flaps, rolling one for the urethra and the other for the external structure of the penis. Over time, the tissue was moved into the appropriate position and a formal urethral anastomosis was performed. Gillies revolutionary operation addressed both urologic and aesthetic function and set the stage for modern phalloplasty.

Free flap phalloplasty began in the early 1980s, first reported by Puckett in 1982 ³ and refined by Chang and Hwang in 1984 ⁴ who refined the design of a tube within a tube free RF flap. This design has become the basis for modern phalloplasty techniques.

Preoperative Considerations

Genital gender surgery is complex not only from a technical standpoint but also, more critically, from a psychosocial perspective. Phalloplasty surgeons cannot extricate themselves from the necessary assessment of a patient's overall medical and psychological health and must consider postoperative care and the social support available to the patient throughout their protracted recovery.

As a group, we follow the guidance of the World Professional Association for Transgender Health Standards of Care when considering patients for genital surgery. While not universally agreed upon, these standards have been adjudicated and modified by gender health professionals over decades, and they generally offer a safe guideline for surgeons embarking on genital gender affirmation surgery. In addition to the criteria outlined in the WPATH standard of care ( Table 1 ), patients must be able to afford a significant time away from work, school, and family for recovery. ⁵

Table 1. WPATH criteria for genital surgery.

1. Persistent, well-documented gender dysphoria.

2. Capacity to make fully informed decisions and to consent to treatment.

3. Age of majority in a given country.

4. If significant medical or mental health concerns are present, they must be well controlled.

5. 12 continuous months of hormone therapy as appropriate to the patient's gender goals (unless the patient has a medical contraindication or is otherwise unwilling or unable to take hormones).

6. 12 continuous months of living in a gender role that is congruent with their gender identity.

Pertinent medical history includes prior gender affirmation and urologic surgeries, hormone therapy (including duration of therapy), history of bleeding or clotting disorders (including a history of multiple miscarriages), voiding dysfunction, urinary tract infections, or kidney stones. Equally important is a patient's psychosocial stability, social support, and personal history of substance abuse or tobacco use. If the patient has a history of clotting disorders or prior flap loss, a hypercoagulable evaluation is indicated ( Table 2 ). It is also critical to understand the patient's expectations and to engage in a frank discussion as to whether these expectations are reasonable and achievable.

Table 2. Hypercoagulability evaluation.

1. Anticardiolipin antibody (IgG, IgM, and IgA).

2. Antithrombin III activity

3. aPTT-LA (lupus sensitive reagent)

4. Factor V Leiden gene mutation

5. Factor VIII activity

6. Homocysteine

7. Protein C activity

8. Protein S activity

9. Prothrombin gene mutation

Radial Forearm Phalloplasty

The RF flap has become the choice flap for transmasculine genital surgery. There are several factors that account for its predominance including a predictable, robust vascular supply, reliable sensory innervation, and its pliability. These attributes translate directly into lower complication rates, fewer necessary operations, and a superior aesthetic result.

Limitations of the RF flap primarily relate to the donor site as well as some limitations with respect to achievable length. The donor site is conspicuous on the forearm and the characteristic rectangular pattern is recognizable. Flap size, particularly length, is limited by the length of forearm. While the forearm reliably provides a phallus that is proportional to the patient, this does not always correspond to the desired length.

Patient Positioning

The patient is placed in the supine position, arms abducted, and the legs placed in stirrups (if performing vaginectomy, urethral lengthening, and scrotoplasty) ensuring all pressure points and nerves are well padded and protected. The donor arm is abducted on a hand table and a tourniquet is placed on the arm. This positioning allows two surgeons to work simultaneously with one harvesting the flap and the second completing the vaginectomy, urethral lengthening, scrotoplasty, and recipient site preparation.

Markings

The RF phallus is a large rectangular design centered over the radial artery. While several modifications exist in the literature, we prefer a design that places the urethral segment on the volar aspect of forearm as this tissue is typically hairless and thin, allowing for facile tubularization.

First, the course of radial artery is marked. A 1-cm × 13 to 15-cm segment for de-epithelialization is placed parallel and just ulnar to the radial artery. The distal urethra is 4 cm in width but widens proximally to 4.5 cm in width. The proximal urethral segment is carried 1 to 1.5 cm beyond the proximal border of the dermal/epidermal portion of the flap—creating an adipofascial extension beyond the rolled urethra. The investing wrap, including the radial artery and cephalic vein is then designed radial to the de-epithelialized segment 9 to 10 cm in width distally and 10 to 14 cm in width proximally. Greater proximal width is required in thicker forearms to facilitate primary closure of the phallus. A lazy S or zig-zag incision is then designed extending proximally to the antecubital fossa to allow for pedicle dissection ( Fig. 1 ).

Fig. 1.

Radial forearm flap design. ( a ) Volar; note ulnarly based urethral segment. ( b ) Radial. ( c ) Dorsal.

Flap Elevation

With the tourniquet elevated, dissection of the flap begins proximally following de-epithelialization of the central segment. The cephalic vein and lateral antebrachial cutaneous (LABC) nerve are isolated and traced proximally. The LABC nerve is then divided proximally. The interval between the brachioradialis and flexor carpi radialis (FCR) is then opened to allow for dissection of the radial artery and its venae comitantes. The radial artery is followed proximally to its takeoff from the brachial artery. Maximal arterial pedicle length is necessary to facilitate arterial repair without the need for vein grafting. The profunda cubitalis vein is preserved linking the deep venae and superficial cephalic venous systems as described by Gottlieb. ⁶ We prefer to complete the entire pedicle dissection while the flap remains in situ as this maintains pedicle tension.

Once the pedicle dissection is complete, a volar vein from the urethral segment is dissected to facilitate specific drainage of the urethral portion of flap. This vein is ligated for subsequent anastomosis. The flap is then elevated ulnar to radial along the volar surface of forearm in a supra-fascial plane. Dissection is subsequently transitioned to a sub-fascial plane at the FCR. The radial artery and venae comitantes are ligated distally. The dissection is then carried ulnar to radial across the dorsal surface of the forearm in a supra-fascial plane, transitioning to subfascial dissection at the brachioradialis. The radial nerve is carefully teased out of the flap preserving all branches to the dorsal hand. The flap is then elevated out of the BR-FCR interval.

Once the flap has been elevated, the tourniquet is let down and hemostasis ensured. The flap is then shaped on the arm ( Fig. 2 ).

Fig. 2.

Radial forearm flap harvest. ( a ) Suprafascial volar dissection with subfascial dissection at the level of the FCR, note preservation of all proximal vascular perforators. ( b ) Radial forearm flap in situ post-harvest. ( c ) Radial forearm flap ICG, note preservation of proximal dermal bridge to bolster proximal pars pendulans perfusion.

Phallus Shaping

Once the flap has been fully elevated, the phallus is constructed via tubularization of the inner urethra, externally wrapping the urethra with the investing portion to form a phallus. The ulnar edge of the flap is then tubularized to the ulnar edge of de-epithelialized segment ( Fig. 3 ). Closure is performed in two layers: first 4-O Monocryl deep dermal and second 4-O Monocryl running suture (Ethicon, Somerville, NJ). The urethra is then tested for leaks and any areas of incompetence are repaired. Once the urethra has been constructed, the radial investing portion of the flap is wrapped around and sewn to itself. Closure is again accomplished in two layers. The distal urethra is inset to the distal portion of the flap with interrupted absorbable sutures, repeatedly bisecting the available tissue to effectively create a purse string closure ( Fig. 4 ).

Fig. 3.

Radial forearm flap shaping. (a) Tubularization of pars pendulans urethral segment. (b) Formation of penile shaft.

Fig. 4.

Radial forearm recipient vessels, femoral artery isolated with arteriotomy in preparation of end-to-side vascular anastomosis.

Microsurgical Considerations

The microsurgical portion of the reconstruction is completed once the urethral anastomosis has been accomplished. This includes neurotization and revascularization of the flap.

There are several options for nerve coaptation, and use of both the clitoral and ilioinguinal nerve has been described. Our preference is the clitoral nerve because it provides analogous sensory input to a penis. Nerve coaptation is performed between the clitoral nerve and the LABC. Additional dorsal sensory branches to the forearm flap are often located and may be routed end-to-side or directly to the clitoral nerve.

There are, likewise, several reliable sources of arterial inflow and venous outflow. So long as care was taken in flap design, the vascular pedicle will easily reach the groin. Our preference is for an end-to-side arterial anastomosis to the femoral vessels ( Fig. 3 ). Occasionally a femoral artery branch of sufficient caliber is available. Numerous veins from the saphenofemoral tree are available for venous outflow.

Donor Site Reconstruction

Donor site reconstruction is important given the visible location on the forearm. Care to ensure excellent graft take will result in the most aesthetic closures. The proximal arm is closed in a standard fashion. The proximal skin is then advanced distally utilizing a barbed suture. The FCR tendon is covered by imbricating the flexor pollicis longus muscle belly over the exposed tendon utilizing a running barbed suture. The forearm is then reconstructed with a sheet skin graft obtained from the thigh. We have found that a thick (18/1,000 to 20/1,000 inch) split thickness skin graft provides the best compromise maximizing graft take while providing a thicker, more aesthetic graft. The graft is bolstered with a negative pressure dressing that remains in place for 5 days. The wrist is immobilized in a splint for 2 weeks, while the fingers remain free.

Anterolateral Thigh Phalloplasty

The ALT flap has become an accepted alternative to the more commonly employed RF flap for female to male genital surgery. While the RF free flap remains the most common and reliable donor site choice, the characteristic forearm scar is recognizable and difficult for patients to conceal in clothing. The ALT flap maintains the advantages of a less conspicuous donor site and flexibility in phallus length. The ALT flap is generally reliable, may be innervated and can be performed at centers without microsurgical capabilities.

Despite these advantages, which are often cited by patients, there are significant limitations to the ALT flap as donor tissue for phalloplasty which are primarily related to flap thickness and variation in the vascular perforator anatomy. Proper patient selection is therefore critical. In nearly all but the thinnest of patients, an ALT phalloplasty requires multiple stages for successful urethral lengthening. Staging involves serial thinning and partial urethroplasty over the course of years with the potential need for a second flap for urethral reconstruction if more conservative measures fail. Unless the thigh anatomy is ideal, patients must be prepared for multiple urethral and thinning surgeries to attain a functional urethra as well as a phallus that is of reasonable diameter for penetrative intercourse. Reasonable thigh anatomy is based on a pinch thickness of less than 1 cm and ideally less than 0.5 cm ( Fig. 5 ). Patients without ideal anatomy may still chose an ALT donor; however, they must forgo urethral lengthening.

Fig. 5.

Appropriate ALT pinch thickness to allow for primary urethral construction. ALT, anterolateral thigh.

Patient Positioning

The patient is placed in a supine position, arms abducted, and the legs placed in stirrups (if performing vaginectomy, urethral lengthening, and scrotoplasty) ensuring all pressure points and nerves are well padded and protected. The donor leg is abducted 30 to 40 degrees at the hip and extended to place the knee in 10 to 15 degrees of flexion ( Fig. 5 ). This positioning allows two surgeons to work simultaneously with one harvesting the flap and the second completing the vaginectomy, urethral lengthening, scrotoplasty, and recipient site preparation ( Fig. 6 ).

Fig. 6.

Operative positioning to allow for simultaneous flap harvest and perineal surgery.

Markings

The ALT phallus is designed akin to the standard ALT flap with several pertinent modifications. The flap should be marked with the patient supine, prior to placement of the donor leg in a stirrup as this placement may distort the standard landmarks. The flap is centered along a line between the anterior superior iliac spine and superior lateral border of patella. This line represents the intermuscular septum between the rectus femoris and vastus lateralis muscles. A pencil doppler is then used to mark cutaneous perforators arising from the descending branch of lateral circumflex femoral artery. These perforators are typically near the midpoint of the reference line and lateral to it. If no perforators are found on doppler investigation, the contralateral thigh may be examined if the patient has been made aware of this possibility preoperatively and has minimal hair on the contralateral thigh.

A rectangular flap is then drawn, incorporating the audible perforators. It is critical to place the flap as distal as possible, typically 5 to 6 cm above the superior border of the patella, to allow sufficient pedicle length for the flap to reach the midline. The flap is marked 20 cm in width distally and 20 to 24 cm in width proximally. Greater proximal width becomes necessary to attain primary closure of the phallus if the thigh becomes thicker proximally. The urethra is designed on the medial aspect, 4 to 5 cm in width. This segment is lengthened and fanned out proximally to allow for anastomosis to the lengthened urethra. A 1.5-cm segment is then outlined for de-epithelialization. The remainder of the flap, typically 16 to 18 cm, is preserved for the external investing wrap ( Fig. 6 ).

If a proximal perforator is present, this vessel may be captured by designing a proximal triangular extension that will be de-epithelialized at inset ( Fig. 7 ).

Fig. 7.

ALT flap design. ( a ) ALT phalloplasty markings. Note the proximal extension of the flap to incorporate all available vascular perforators. ( b ) ALT phalloplasty lateral markings including the penile shaft. ( c ) ALT phalloplasty medial markings including the urethral segment. ALT, anterolateral thigh.

Flap Elevation

Dissection of the flap is begun proximally to identify the lateral femoral cutaneous nerve(s). These lie deep to Scarpa's fascia and immediately superficial to the investing muscular fascia of the thigh. Most commonly, the nerves overly the intermuscular septum between the rectus femoris and vastus lateralis. A proximal superficial vein, while not reliably present, may be harvested as well to augment venous outflow via subsequent anastomosis to the greater saphenous vein. Once the nerve(s) have been identified, the dissection continues in accordance with a standard ALT harvest.

The flap is elevated in a suprafascial plane working medial to lateral. The medial incision is made, scything toward the flap to avoid excessive incorporation of medial thigh fat. The suprafascial dissection is carried over the rectus femoris. The rectus femoris fascia is incised and the dissection continues in a subfascial plane. The interval between the rectus femoris and vastus lateralis is then opened and the descending branch of the lateral circumflex femoral artery and its venae comitantes is identified. The perforating vessels are then dissected through their fascial or intramuscular course. Once the perforators have been dissected free, the remainder of the dissection can be completed in a suprafascial plane from lateral to medial.

Generally, we do not recommend thinning of the ALT flap at the primary harvest for ALT phalloplasty. The flap is quite large and thinning, no matter how meticulously done, can compromise the circulation to the flap periphery. Additionally, given the size of the flap, we preserve all possible perforating vessels to ensure adequate perfusion, and more pertinently, adequate venous drainage. Distal medial perforators may also be used to “supercharge” the distal portion of the flap via anastomosis to the terminal end of descending lateral circumflex femoral vessel.

Once the flap has been isolated on its perforating vessels, the vascular pedicle is followed proximally. Pedicle dissection is quite extensive and requires sacrifice of the vascular branch to the rectus femoris and dissection up to the origin from the femoral artery and vein. Dissection to the origin at the profunda femoris artery is critical to allow the flap to reach the midline. The rectus femoris and sartorius are elevated to allow for passage of the flap and its accompanying vascular pedicle deep to these muscles. The flap is passed sequentially, deep to the rectus femoris and then to the sartorius. The pedicle is checked after each positional change to ensure no kinks or twists are there that might compromise the vascular inflow/outflow of the flap ( Fig. 7 ).

Phallus Shaping

Once the central 1.5-cm strip is de-epithelialized and the flap and pedicle have been fully elevated and mobilized to the patient's midline, the phallus is then constructed via tubularization of the inner urethra, hence externally wrapping the urethral to form a phallus. This step may be performed prior to flap elevation if it is certain that a urethral lengthening will be possible or after flap elevation with the skin held on tension. The medial edge of the flap is then tubularized to the medial edge of the de-epithelialized segment ( Fig. 8 ). Closure is performed in two layers: first 3-O Monocryl deep dermal; second 4-O Monocryl running suture (Ethicon, Somerville, NJ). The urethra is then tested for leaks and any areas of incompetence are repaired. Once the urethra has been constructed, the lateral portion of the flap is wrapped around and sewn to itself ( Fig. 9 ). Closure is again accomplished in two layers.

Fig. 8.

ALT flap shaping. ( a ) ALT flap following harvest, not vascular pedicle, and lateral femoral cutaneous nerves for coaptation. ( b ) ALT flap with urethral segment tubularized. ( c ) ALT flap in situ prior to transfer to the midline. ALT, anterolateral thigh.

Fig. 9.

ALT flap inset. ( a ) ALT flap inset, ventral surface. ( b ) ALT flap inset. ALT, anterolateral thigh.

The distal urethra is inset to the distal portion of the flap with interrupted absorbable sutures, repeatedly bisecting the available tissue to effectively create a purse string closure. Alternatively, distal shaft skin may be closed as a “fishmouth” to the inner urethra. This closure creates a more acceptable shape to the distal phallus but results in a dorsal scar.

Donor Site Reconstruction

Donor site closure is accomplished by reapproximating the vastus lateralis and rectus femoris as well as the interval between the rectus femoris and sartorius with an absorbable barbed suture. The corners of the skin defect are then advanced to reduce the overall size of the wound. The skin is imbricated to the underlying muscle with an absorbable barbed suture to achieve a uniform wound bed. A 14/1,000 inch skin graft is harvested from the contralateral thigh, meshed 2:1 and sewn into place on the harvest bed. We prefer to bolster the skin graft with a negative pressure wound dressing.

Urethral Lengthening and Perineal Masculinization

The primary goals of having an aesthetic phallus and standing micturition require a fully lengthened cylindrical urethra free of fistulas, strictures, and diverticula. Another important goal for many patients seeking phalloplasty is to attain male-equivalent scrotal and perineal anatomy. The urethra must course from the native urethral meatus to the tip of the phallus and is composed of an interposed urethral segment (pars fixa, PF) and the pendulous urethral segment (pars pendulans, PP) provided by the transplanted flap tissue. Additional components of a fully masculinized perineum include vaginectomy, creation of a pouch-like scrotum (scrotoplasty), and perineal closure.

Surgical Technique

The patient is placed in dorsal lithotomy and a suprapubic tube is placed for urinary diversion. Vaginectomy involves mucosal destruction via sharp dissection and/or cauterization. We prefer a combination of both: sharp dissection distally and fulguration proximally. Some surgeons prefer full mucosectomy; however, the time required and blood loss are higher. Other surgeons perform robotic vaginectomy, but this technique may cause a neurogenic bladder where bladder function is lost, and patients have to catheterize or Valsalva void to empty their bladder.

The pars fixa urethra is made from labia minora tissue. Some surgeons will use autologous grafts like buccal mucosa or vaginal mucosa for part of the PF urethral reconstruction, or vaginal wall flaps. However, most use some modifications of labia minora flaps. The endodermal labia minora is pink and closely resembles mucosa; the ectodermal labia minora is hairless thin skin. The specific flap we prefer using is a ring of labia minora tissue around the urethral meatus and vaginal introitus. This ring maintains vascularity through a rich anastomotic network between the posterior internal pudendal and anterior external pudendal vascular system. Via a posterior dissection of mostly endodermal labia minora tissue, a ring-shaped flap is raised which simultaneously moves urethral tissue anteriorly and releases the ventral chordee of the clitoris. This allows extension of the PF urethra to a lengthened clitoris so that the PF PP urethral anastomosis can be done oftentimes at the lower abdominal skin level without tension. An additional benefit of the ring flap is the ability to create local proximal urethral fascial extensions that are used to cover the proximal urethral anastomosis. The de-epithelialized components are secured to the midline vaginectomy site as well as posterolateral, covering the urethral anastomosis completely with well vascularized tissue ( Fig. 10 ).

Fig. 10.

Pars fixa urethral lengthening. ( a ) Labia minor flaps marked in situ. ( b ) Excision of periurethral fornices. ( c ) Vaginectomy. ( d ) Labia minora flaps elevated. ( e ) Tubularization of pars fixa urethra. ( f ) Complete pars fixa urethral lengthening.

Once vaginectomy and PF urethroplasty are completed, the clitoral glans and shaft skin are removed. This allows burial of the clitoris and dissection of dorsal nerve. There are two dominant nerve bundles just lateral to the midline dorsal vein. We dissect the nerve bundle ipsilateral to recipient vessel dissection site ( Fig. 11 ). The degloved clitoris with nerve and extended urethra is translocated to an area under the upper aspect of the pubic symphysis, where a circular excision is made to serve as phallus attachment site ( Fig. 12 ).

Fig. 11.

Dissection of the dorsal (clitoral) nerve, ipsilateral to vascular pedicle.

Fig. 12.

Scrotoplasty. (a) Labia majora flaps in situ. (b) Labia majora flaps elevated. (c) Perineal closure in layers. (d) Complete perineal masculinization with scrotoplasty and perineal closure.

Perineal masculinization continues externally with scrotoplasty and perineal reconstruction. Initially, excess ectodermal labia minora tissue and clitoral shaft skin are excised. The remaining labia majora are then both elevated as U -shaped flaps up to the level of adductor tendons and approximately 1 cm thick. These flaps are retracted superolaterally. Perineal reconstruction begins by covering the entire suture line of the PF urethra with a bulbospongiosus musculofascial layer, followed by an adipofascial and skin layer. Frequently, the inferior most aspect must be lifted and closed to neighboring inner thigh skin. This creates a flat perineum without a shelf ( Fig. 13 ). Complex scrotoplasty can then be completed by rotating and advancing each labia majora flap anteromedially. This creates a pouch-like scrotum in the more anatomical position. There are many options for scrotoplasty, including simple midline labia majora closure or V-Y majora tissue rearrangements. However, these methods produce a perineally positioned scrotum that appears labial and not desired by patients.

Fig. 13.

Urethral anastomosis, pars fixa to pars pendulans. (a) Urethral segments aligned with catheter in place (b) Urethral anastomosis.

At this time, phalloplasty with PP urethroplasty is completed and the free or pedicled flap is moved to the orthotopic location. The PF and PP urethral segments are then connected with 5–0 absorbable suture. The microsurgeons then co-apt the dorsal nerve to the lateral antebrachial or lateral femoral cutaneous nerve for RF or ALT patients. The adipofascial extension from the flap is then wrapped around this urethral anastomosis ( Fig. 14 ). The flap is then inset once the microsurgical portion of the case has been completed ( Fig. 15 ).

Fig. 14.

Radial forearm phalloplasty with scrotoplasty.

Fig. 15.

Radial forearm phalloplasty with scrotoplasty at time of erectile device placement. (a) Intra-operative aesthetic appearance (b) Aesthetic appearance at 1 year post op.

Surgical Outcomes In Phalloplasty

The vast majority of patients who undergo phalloplasty desire standing micturition, penetrative sexual function, and proper aesthetics. There are no available peer-reviewed standardized patient-reported outcome measures available for the evaluation of these surgical goals. There is also a lack of consensus among surgeons as to standardized outcomes, and as such, complication rates are highly varied in the existing medical literature. An alternative metric is the evaluation of surgical outcomes from urethral lengthening and prosthetic placement surgery.

Urethral Surgery Outcomes

Common urethral complications are fistulas and strictures, followed by less common defects like diverticula and calculi. To minimize confusion, urethral revision rates will be our primary outcome measure. From October 2017 to May 2022, 181 consecutive single stage radial artery forearm free flap phalloplasty patients who had simultaneous UL and vaginectomy were evaluated for urethral complications. In total, 71 patients (39%) developed a fistula, stricture, or both. However, since many of the fistulas were small, they spontaneously healed. Surgical revision for a urethral fistula/stricture was required for 39 patients (22%). The average length of a urethral defect was 1.5 cm and most patients required repair on average 5 months after phalloplasty. No patients required a perineal urethrostomy. Surgical revision rates are probably the most reliable comparable metric in phalloplasty studies given the heterogeneity of urethral complications reporting. Many studies and meta-analyses report a urethral revision rate of approximately 50%.

Penile Prosthetic Surgery Outcomes

Many patients will eventually want and need a penile implant. The neophallus is composed of skin and adipose tissue; it has no erectile tissue for non-surgical therapies like phosphodiesterase 5 inhibitors and corpora cavernosal injections. Surgery is therefore required for most patients to achieve penetrative sexual function. Around 1 year after phalloplasty, patients without urethral problems and with neophallus sensation are candidates for implant surgery. The most common implant used is the inflatable penile prosthesis (IPP). This implant has three components: a cylinder component goes into the neophallus; a reservoir is positioned in the space of Retzius; and a pump that controls inflation and deflation is placed in a pouch-like neoscrotum. Placement of the IPP involves a horizontal incision directly anterior to the top of pubic symphysis. This approach allows exposure of the lower anterior rectus sheath and subsequent exposure of the rectus abdominus muscles. Midline dissection between both muscles safely and reliably accesses the Space of Retzius. Next, the dissection is performed under the pubic symphysis for 7 to 8 cm from the level of skin incision, followed by dissection into the neophallus in the midline, above the urethra. The distance between the inferior pubic symphysis dissection and the tip of the neophallus dissection plane dictates the length of cylinder required. The final dissection space through the initial horizontal incision is made into the hemiscrotum opposite the side of neophallus vascular pedicle. The three-piece IPP is then anchored to the pubic bone and its components are positioned in their respective spaces. Patients who do not want the inflatable implant or patients who do not have a pouch like scrotum may desire the malleable penile prosthesis (MPP). MPP placement is technically easier as only one dissection space is required.

Similar to urethral complications, the reporting of implant surgery complications varies widely. As such, the more reliable complication rate to follow is the surgical revision rate. In general, the averaged risk of needing a surgical revision after penile implant placement is 40%. In our patient cohort from October 2017 through May 2022, 25 (19%) out of 130 IPP patients and 14 (35%) of 40 MPP required a surgical revision. The most common reasons for revision in the IPP group were related to pump component migration or erosion. In the MPP group, detachment from the pubic bone anchor site was the most common. Overall, the risk of infection was <5% and only one out of 170 patients developed partial flap necrosis.

Conclusion

Female to male genital surgery has evolved immensely over the past several decades from the creation of simple, insensate abdominal flap phalli to sensate, aesthetically accurate, functional reconstructions. Our phalloplasty experience at the Buncke Clinic spans the last decade and includes over 500 free RF flap phalloplasties and over 100 ALT flap phalloplasties. This clinical experience has evolved and continues to do so; however, this experience has informed several clinical opinions. First and foremost, that urethral construction may be safely and efficiently accomplished in a single stage operation with urologic outcomes equivalent to and often superior to staged procedures. The ability to construct the urethra in a single operation is advantageous with respect to both operative time and patient recovery. This approach relies on meticulous urologic reconstruction and requires highly reliable flap survival. We believe that urethral complications are minimized by several techniques including preservation of a vascularized adipofascial cuff at the site of urethral anastomosis, ensuring proximal capture of all radial arterial perforators with a dermal bridge to the urethral segment specifically preserving a separate venous drainage from the urethral segment of the flap. Additionally, extending the PF urethra to mons region helps minimize tension at the PF PP urethral anastomosis.

Our favored flap choice is a free RF flap ( Fig. 12 ). While we continue to perform ALT phalloplasties on select patients with appropriate surgical anatomy, the complication profile is much less favorable and both functional and aesthetic outcomes are inferior to those that can be accomplished with a RF flap. The RF flap has superior vascularity, pliability, and sensory recovery. We prefer an end-to-side anastomosis of the radial artery to the femoral system, although on occasion a femoral side branch or a deep inferior epigastric artery is utilized for vascular inflow. Venous outflow is generally into central circulation via anastomosis to the saphenous vein and we prefer to drain both the superficial and deep venous systems either through a common cubital vein or via an additional anastomosis of the venae. A separate vein draining the urethral segment is also repaired. Glansplasty may be performed at the time of primary operation; however, aesthetic results, specifically preservation of coronal projection are superior when delayed 4 to 6 months.

Testicular implant placement is facilitated by the creation of a pouch-like scrotum and implants may be placed 6 months or more following the primary operation. Placement of an erectile device should be deferred for 1 year following the primary operation to allow for any urethral complications to surface and to be addressed. This period also allows for sufficient nerve regeneration with the phallus to allow patients to protect the implant.

Overall aesthetic and functional results with phalloplasty are excellent and patient satisfaction is quite high. Urologic complications remain the greatest clinic hurdle. However, with meticulous surgical care, these complications can be minimized in number and severity and effectively addressed when they do arise without salvage flaps or diverting perineal urethrostomies.