Overview of Surgical Techniques in Gender-Affirming Genital Surgery

Mang L. Chen; Polina Reyblat; Melissa M. Poh; Amanda C. Chi

Disclosures

Transl Androl Urol. 2019;8(3):191-208. 

In This Article

Transmasculine Genitourinary Surgery

Preoperative Assessment

By the time patients schedule their consultation, many will have already been on hormone therapy for over 1 year and will have established mental and primary health care. Many will also have had double mastectomy and hysterectomy. Patients want to explore their options for GRGUS, which for transmasculine individuals, includes metoidioplasty and phalloplasty, with variable desires for vaginectomy, scrotoplasty, and urethroplasty. Most patients will want all of these procedures; some will want to exclude part of the genitourinary reconstruction for individualized reasons. For example, some patients do not want urethroplasty to avoid the risks of urethral reconstruction, while others avoid vaginectomy. During the history portion of the consultation, ascertainment of the patient's surgical goals is vital to determining which surgery is most appropriate. Patients opting for metoidioplasty generally do not want donor site morbidity and accept a small phallus; patients seeking phalloplasty want a larger and physiologic appearing phallus. For patients whose primary goal is standing micturition, phalloplasty with full length urethroplasty is the more appropriate choice, although clitoral enlargement from hormone therapy may allow thin patients with minimal surrounding genital tissue to void standing after metoidioplasty with urethral lengthening.

As with all surgeries, a thorough history and physical is important. A history of hypertrophic scarring or keloids negatively impacts postoperative complications—specifically, urethral strictures. Smoking tobacco, use of nicotine products, or inhalational products of any kind increases wound and other perioperative complications[16–19] to the point where surgery may be cancelled if there is evidence of smoking within 3 months of surgery. Diseases treated with immunotherapy such as steroids may also affect wound healing and are strong contraindications to surgical therapy. Obesity with specific adipose distribution to the pannus or mons pubis and thighs may also prevent safe surgery and at the minimum, negatively impact overall aesthetics and function. A suggested body mass index (BMI) cutoff is 35 kg/m2for patients desiring radial forearm free flap (RFFF) phalloplasty; ideal body weight is suggested for patients interested in metoidioplasty and anterolateral thigh (ALT) phalloplasty. Despite these guiding principles, BMI alone is a poor indicator for metoidioplasty and ALT phalloplasty candidacy. Physical exam assessment of the surgical sites offers far more accurate predictions of postoperative aesthetics and function.

Metoidioplasty

Patients desiring metoidioplasty want masculine-appearing genitalia without the morbidity associated with a donor site. This procedure involves chordee release with or without vaginectomy, urethroplasty, scrotoplasty, and perineal reconstruction. A simple metoidioplasty is chordee release, neurovascular pedicle reposition, and ventral phallus skin closure. A full metoidioplasty, in contrast, includes simple metoidioplasty procedures with vaginectomy, scrotoplasty, and urethroplasty. The ideal candidate for metoidioplasty is a thin, healthy patient with minimal surrounding genital tissue and pronounced clitoral enlargement from hormone therapy. The surgical technique employed for patients wanting a full metoidioplasty starts first with vaginectomy. Vaginectomy requires the excision and/or destruction of the vaginal mucosa, followed by a colpocleisis to obliterate the canal (Figure 11A,B). Thick polydioxanone (PDS) suture is used during vaginectomy to decrease the risk of urethral pseudodiverticulum formation at the native urethral anastomotic site. Care is taken to preserve neighboring labia minora tissue as this is used to lengthen the urethra from the native urethral meatus to the glans clitoris (Figure 12). Our urethroplasty technique is modeled after the "ring" flap metoidioplasty first described by Takamatsu.[20] During dissection of the ring flap, the chordee is released via transection of the ventral attachments down to the corporal bodies of the clitoris, creating a gap between the base of the clitoris and the urethral meatus. The peri-urethral fornices flanking the urethral meatus are excised (Figure 13A,B) and the inferior portion of the ring flap is divided and then sewn to the dorsal aspect of the native urethral meatus, filling the gap (Figure 14A, B). The dorsal urethral plate is sewn in several layers, with the first layer securing the submucosal flap tissue to the tissue surrounding the corpora cavernosa (Figure 15). Further urethral reconstruction around the meatus is completed, followed by ventral closure and tubularization of the urethra to the glans clitoris (Figure 16). At the native urethral meatus, the ventral anastomosis with the ring flap will often have excess tissue that can be de-epithelialized and used to directly cover the urethral suture line at this location (Figure 17). Excess labia minora skin is then similarly de-epithelialized, creating a subepithelial vascular layer that can be used to cover the urethral suture line (Figure 18). The remaining labia minora skin is then closed ventrally to create a cylindrical phallus. The inferior aspect of the labia majora is then incised via a "U" shaped incision to create flaps that are lifted, rotated and sewn to create a pouch like scrotum just inferior to the base of the phallus (Figure 19). The perineal wound is then closed with several layers of absorbable suture. We place a suprapubic (SP) tube that remains for 2–3 weeks. We close the urethra around a Coude catheter that is removed immediately postoperatively to avoid the risk of catheter related traumatic hypospadias. There are numerous other metoidioplasty techniques described,[21–26] but we favor the ring flap technique as it avoids dorsal clitoral dissection, corporal dissection, and urethral grafts.

Figure 11.

Vaginectomy. (A) After distal sharp mucosal excision, the remainder of the vaginal mucosa is fulgurated; (B) colpocleisis is carried out with thick polydioxanone suture.

Figure 12.

Markings demonstrate tissue used for pars fixa urethroplasty.

Figure 13.

Creation of smooth dorsal urethral plate. (A) There are indentations of mucosa flanking the native urethral meatus—the periurethral fornices; (B) the fornices are demucosalized.

Figure 14.

Flap harvest for urethral lengthening. (A) The inferior aspect of the "ring" flap is divided to facilitate flap harvest; (B) labia minora flaps are elevated.

Figure 15.

The dorsal urethral plate is created by bringing both parts of the original ring to the midline between the urethral meatus and the inferior aspect of the clitoris after chordee release.

Figure 16.

Pars fixa urethroplasty is completed with ventral closure.

Figure 17.

De-epithelialized portions of the labia minora flaps are preserved and used as additional coverage over the native urethral-to-ring flap anastomosis.

Figure 18.

Vascular de-epithelialized flaps from the labia minora tissue not used for urethroplasty are preserved for coverage of the pars fixa urethral suture line.

Figure 19.

Immediate postoperative photo of patient after metoidioplasty with urethral lengthening, vaginectomy, scrotoplasty, and perineal reconstruction.

Patients undergoing metoidioplasty are either discharged home later that day or watched overnight; rarely do patients require longer hospital stays. We advise patients regarding expected phallus swelling and incisional drainage of serosanguinous fluid. They are advised to ambulate slowly but regularly and notify us of any worsening symptoms. At their first postoperative visit one week later, if the phallus swelling is minimal, patients can attempt a voiding trial. If they are able to void reliably well with minimal post void residuals, the SP tube may be removed on their subsequent visit. If there is significant postoperative swelling, a voiding trial is delayed a week. During their voiding trial, if an urethrocutaneous fistula is noted, voiding trial is delayed for an additional week. Most fistulas are small and heal spontaneously with good wound care and nutrition. On rare occasion, fistula repairs are required. The SP tube is removed if the patient can void successfully. Some urologists will perform voiding cystourethrograms (VCUGs) or retrograde urethrograms (RUGs) prior to SP tube removal. Patients are thereafter counseled to watch for obstructive voiding symptoms as about 10% of patients are prone to stricture formation within the first year (unpublished data). A recent meta-analysis reported metoidioplasty associated urethral complication rate to be around 25%.[27]

About six months after metoidioplasty, some patients will want/need additional procedures, the most common of which is testicular implant insertion with or without monsplasty and upper labia majora fold reduction. This is an outpatient procedure and involves strategic dermatolipectomy of the mons pubis and upper majora tissue to reduce the surrounding tissue around the phallus. Testicular implants can be placed dependently in the scrotum via the labia majora incisions with a purse-string type suture placed superiorly to decrease the risk of cephalad migration of the implant.

For patients who develop strictures or who have fistulas that do not heal, urethral reconstruction is required. Fistula repair involves the excision of the fistula tract followed by multi-layered closure of the site. This can often be completed in a single stage.

Phalloplasty

Patients seeking phalloplasty often desire a proportionally sized phallus with neophallus sensation, the ability to urinate standing, and eventual penetrative sexual function via a penile prosthetic. There are a multitude of techniques and surgical staging options available for phalloplasty.[28–52] The most common of technique is a single-stage RFFF phalloplasty with vaginectomy, urethroplasty, scrotoplasty, and perineal reconstruction. The distinct advantages of the radial forearm donor site are the tissue's similarity to genital skin, skin innervation, and a highly reliable neurovascular supply. The major disadvantages are the conspicuous donor site scar and potential for diminished hand function. Patients with an intact palmar arch without prior history of prohibitive radial forearm trauma or intravenous drug use are candidates for the RFFF—widely considered the gold standard for phalloplasty. The second most common donor site is the ALT pedicled or free flap. The advantage of this sensory flap is its more concealable donor site. The main disadvantage is that few patients have the anatomy sufficient for a single staged "tube in tube" ALT phalloplasty as this flap is frequently thicker and will require multiple stages of neophallus and neourethral reconstruction to achieve a functional, more aesthetic and proportionally sized phallus. Other flap options include the musculocutaneous latissimus dorsi free flap, the tibial free flap, and abdominal or groin pedicle flaps.[40,44,53,54] These flaps are not offered in our practice given their lack of sensory innervation and their need for staged urethral and neophallus reconstruction. In nearly all RFFF phalloplasty patients, full length urethroplasty and physiologic aesthetics are achievable in the first stage, minimizing the need for multiple stages of neophallus and urethral reconstruction.

The surgical team is composed of microsurgeons and a reconstructive urologist. The patient is positioned in dorsal lithotomy position with the arms perpendicular to the body. The microsurgeons harvest the flap and create the pars pendulans (PP) urethra and neophallus with or without glansplasty depending on the flap used and the patient's specific anatomy. We avoid primary (immediate) glansplasty in ALT flaps and thin RFFFs due to the risk of distal flap necrosis. Thicker RFFF neophalluses accommodate concomitant glansplasty due to a reliable distal flap blood supply from the more abundant adipose tissue. During flap harvesting and neophallus creation, the reconstructive urologist performs the vaginectomy, pars fixa (PF) urethroplasty, scrotoplasty, and perineal reconstruction in a fashion similar to the methods utilized during metoidioplasty. The key differences are the following: clitoris shaft and glans de-epithelialization, dorsal nerve dissection, transposition of the clitoris and PF urethra, and a more extensive scrotoplasty with perineal reconstruction. The clitoris de-epithelialization is required to expose one of the two dominant dorsal nerve branches (Figure 20). This is dissected free and later coapted to the antebrachial cutaneous nerve(s) of the RFFF. The neophallus recipient site in front of the mons pubis is created and the clitoris and PF urethra is translocated to this region. The complex scrotoplasty is then performed by raising labial majora flaps based on the external pudendal blood supply that arises superiorly. The flaps are then lifted and rotated to create a pouch-like scrotum (Figure 21). The perineal reconstruction focuses first on urethral suture line coverage with local flaps. The bulbospongiosus fibromuscular layer covers the PF urethral suture line directly (Figure 22) followed by perineal fat and inner thigh skin approximation to create a flat, male appearing perineum (Figure 23).

Figure 20.

Dorsal nerve dissected free from one side of a de-epithelialized clitoris.

Figure 21.

Pouch-like anteriorly positioned scrotum after labia majora flap elevation, rotation, and advancement.

Figure 22.

Bulbospongiosus muscle layer is used to cover the proximal pars fixa urethroplasty suture line.

Figure 23.

Inner thigh skin is brought towards the midline to complete the perineal reconstruction.

The patient is then repositioned supine upon completion of the phalloplasty, vaginectomy, urethroplasty, scrotoplasty, and perineal reconstruction. Groin dissection of the contralateral femoral vessels is carried out by the microsurgeons. The urologist then passes a Coude catheter into the bladder through the PP and PF urethra. This facilitates the PF and PP urethral anastomosis, which is performed with 5–0 PDS suture (Figure 24). The adipofascial extension from the flap covers the urethral suture line at this location (Figure 25). The microsurgeons then coapt the nerves and complete the vascular anastomoses under an operating microscope. The groin wound and donor site are then closed, and split thickness skin grafts (STSG) from the thigh are used to cover the donor site. The phallus is attached to the scrotum and prepubic skin (Figure 26).

Figure 24.

PF and PP urethral anastomosis. PF, pars fixa; PP, pars pendulans.

Figure 25.

Adipofascial flap from the RFFF covers the PF-PP urethral suture line. RFFF, radial forearm free flap; PF, pars fixa; PP, pars pendulans.

Figure 26.

Immediate postoperative appearance of neophallus and scrotum after RFFF phalloplasty, urethroplasty, vaginectomy, scrotoplasty, and perineal reconstruction. RFFF, radial forearm free flap.

Patients are hospitalized for an average of 5 days, with 4 days of bedrest followed by ambulation. The first two days require every 1–2 hour Doppler checks of the phallus. On day 5, patients are encouraged to walk. If they are walking well with good pain control and gastrointestinal function, they are discharged from the hospital with the urethral and suprapubic catheter. Thereafter, they are followed weekly for 4 weeks. At the first postoperative visit, the urethral catheter is removed. At the second visit, if there is minimal neophallus swelling and the incisions continue to heal well, patients are instructed to void with the SP tube clamped. If they are voiding well with minimal post void residuals, the SP catheter is removed at their third postoperative visit. Some urologists will perform VCUGs or RUGs prior to catheter removal.

Complications are common.[35,55–60] Fortunately, most are minor, including open wounds and urinary tract or skin infections. These are minimized by instructing patients to ambulate with small steps and minimize large range of motion movements, especially when getting in and out of cars and when sitting from a standing position. Patients are also advised to keep the surgical sites clean and position the phallus about 45 degrees from the plane of their body. Intermediate grade complications often involve the urethra, including fistulas and strictures. About one-third of our RFFF phalloplasty patients develop a fistula and/or stricture, and about half of these patients will require surgical repair 3–6 months after phalloplasty. In our experience, these risks and others are higher in single stage ALT phalloplasties compared to single stage RFFF (citation). Major complications will require surgery during their hospitalization and includes problems such as vascular thrombus formation and/or groin or perineal expanding hematomas. Fortunately, these complications are rare. Patients are at risk for stricture formation for about 1 year (and perhaps longer) after surgery given the natural history of wound maturation.[61] We recommend that patients get an uroflow and post void residual determination every 3–4 months postoperatively.

Around 12 months after phalloscrotoplasty or urethroplasty, patients who are stricture recurrence free with neophallus sensation may want penile and testicular implants. Patients who desire further neophallus reconstruction via glans revisions or neophallus size reduction or shaping are encouraged to do so about 6 months prior to implant insertion to minimize risk of penile implant complications—specifically, erosion and infection.

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