Introduction
With increasing social acceptance of the transgender community, the number of trans-identifying patients is increasing in the United States, with an estimated 0.39% to 2.7% of the US population identifying as transgender or gender nonbinary. Expanding insurance coverage of gender-affirming surgery (GAS) will likely lead to a rapid rise in the number of these procedures being performed in the coming years. A testament to this growing need is the investments various institutions across the country are putting into building centers for transgender care. While the overall process of transitioning is multidisciplinary, the urologist has played and will likely continue to play a critical role. As early adopters of the robotic platform, urologists are equipped to apply these skills to GAS. In this chapter we discuss the primary robotic applications in GAS—primary and revision penile inversion vaginoplasty (PIV) as well as vaginectomy. Furthermore, we aim to review the current literature on outcomes of these techniques while overlaying our clinical experience when appropriate.
Robotic peritoneal flap penile inversion vaginoplasty
Introduction and history
PIV via a perineal approach is the most common method of gender-affirming genital reconstruction for transgender women. While variations of this technique are described extensively in the literature, outcomes are limited by small cohort size and a lack of standardized measures which encumbers comparison across techniques. Dunford et al. reviewed complications across three techniques—PIV, penoscrotal, and bowel substitution. The authors report bleeding as the most common intraoperative complication (5.01%), wound infection as the most common immediate postoperative complication (14.65%), and a 23.3% rate of external/aesthetic revision. This technique is at times limited by the paucity of scrotal and penile skin in some patients, leading to a shortened canal. A potential solution to this limitation is to use a flap or graft to augment the patient’s native penile and scrotal tissue. Use of the peritoneal flap to increase vaginal length was first described by Russian gynecologist M.I. Ksido in 1933. It was later popularized by Davydov and Zhvitiashvili for patients with congenital vaginal agenesis. , In 2019, an NYU group published the first large series of patients undergoing gender-affirming robotic peritoneal flap vaginoplasty (RPFV). This method uses an antegrade abdominal approach concomitantly with a retrograde perineal approach to maximize the depth of the neovaginal canal.
Preoperative considerations
Patient selection is critical to ensuring a successful surgical outcome and a satisfied patient. Preoperative guidelines at our institution are adapted from the World Professional Association for Transgender Health (WPATH) criteria ( Table 31.1 ). Prior to the surgical consult, the patient needs to have been taking hormones for at least 1 year unless not desired or medically contraindicated. While prior WPATH criteria mandated that the patient needed to have lived in his or her identified gender role for at least 1 year in order to provide the patient ample opportunity to gain awareness and begin to overcome the multifaceted challenges of transitioning, the most recent WPATH criteria note that this requirement does not accurately represent the lived experiences of many transgender patients who do not express their gender in a binary manner. In addition, written documentation from a single provider who has demonstrated competencies in the assessment of transgender and gender diverse people wishing to undergo gender affirming treatment is recommended. This attempts to evaluate the patient’s ability to successfully navigate the postoperative course including perioperative recovery but also the possibility of complications and lifelong care of their new bodies. In our practice, patients are encouraged to attain a body mass index (BMI) of less than 35 kg/m 2 and to cease smoking for at least 2 months to optimize both intraoperative outcomes and postoperative recovery. Preoperative preparation includes hair removal from the penile shaft and scrotum with either electrolysis or laser treatment. In addition, patients are encouraged to attend a course on vaginal dilation and pelvic floor physical therapy prior to surgery. The latter has been demonstrated to decrease the rate of postoperative pelvic floor dysfunction. With evolving literature, there is a dearth of evidence in support of hormone discontinuation prior to surgery. Consequently, we no longer require patients to discontinue their hormonal treatment at the time of surgery. No bowel preparation is required.
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Surgical technique
The patient is positioned in dorsal lithotomy position, sequential compression devices are applied, and subcutaneous heparin is given for venous thromboembolism prophylaxis. Antibiotic prophylaxis is administered, and a Foley catheter is placed into the bladder. In our experience, administration of 1 g thromboxane prior to incision and 1 g at the end of the case is beneficial in minimizing intraoperative bleeding.
The adductor longus tendons, groin creases, and midline are marked. In addition, a 2-cm-wide by 1-cm-long rhomboid flap is marked with the lateral borders at the ischial tuberosities and the tip at the perineal-scrotal junction. The scrotal skin from the base of the penis to the perineal-scrotal junction is excised, leaving the tunica vaginalis behind. It is thinned on the back table for use as a full-thickness skin graft as part of the vaginal canal lining. The remaining lateral tunica vaginalis becomes incorporated into the soft tissue of the labia.
If the patient has not had prior orchiectomy, bilateral simple orchiectomy is performed at this time. The tunica vaginalis is opened, and the testicle is delivered. The spermatic cord is skeletonized free of tunica vaginalis and adventitia to the external inguinal ring. The cord is ligated with 0-silk suture as proximally as possible so that the stump of the cord can fully retract into the inguinal canal.
The tissue over the proximal penile urethra is then dissected, freeing the urethra nearly circumferentially. The overlying bulbospongiosus muscle is then excised to expose the bulbar urethra. The debulking of the bulbospongiosus muscle is crucial to providing a satisfactory voiding stream for patients because residual tissue may lead to an upward-directed stream.
The penis is then degloved and disassembled. A circumcising incision is made approximately 2 cm proximal to the corona to allow for adequate clitoral hooding. Degloving between the dartos and Buck fascia continues proximally until the penis can be inverted. Care is taken to preserve the neurovascular bundle at dorsal midline. The urethra is separated off of the tunica albuginea of the bilateral corpora to the level of the adductor longus and amputated. Bilateral ventral corporotomies are made distally, and the corpora are opened to the base bilaterally. Spongy erectile tissue and the corporal septum are then removed with a periosteal elevator. The septum between the two corpora is excised with electrocautery. Care is taken to ligate the corporal vessel at the base. The corporotomies are closed with running 4-0 PDS suture.
Attention is then turned to the external dissection of the vaginal canal. The space between the bulbar urethra and the bulbospongiosus muscle is hydrodissected with dilute epinephrine. The space underneath the proximal urethra is dissected toward the pelvic floor, taking care to leave rectum down and uninjured.
The robotic portion of the case may occur concurrently with the perineal dissection if there are two surgical teams present. Port placement on an Xi robot is similar to a routine pelvic case such as prostatectomy, while the single-port (SP) robotic trocar can be placed via supraumbilical incision at midline ( Fig. 31.1 ). The SP allows for greater mobility within a narrow pelvis, increased working space for a perineal surgeon, and has the added benefit of improved cosmesis from a single incision. The abdomen is entered using an open cutdown approach. An additional 5-mm assistant port is placed in the left lower quadrant under direct visualization. The patient is placed in steep Trendelenburg.
Anatomically, the vas deferens separates the anterior and posterior peritoneal flaps and the ureters are the lateral borders of the posterior flap. The superior border is the sacral promontory ( Fig. 31.2 ). Initial incision is made horizontally along the peritoneal ridge at the rectovesical junction just posterior to the seminal vesicles. Dissection is carried distally underneath the prostate and seminal vesicles within Denonvilliers fascia toward the pelvic floor. The robotic instruments are eventually palpable through the perineal incision. The two incisions are then connected, and the space is widened by the robotic surgeon until either four fingers or the largest vaginal dilator is able to be placed into the vaginal canal ( Fig. 31.3 ). This may necessitate partial transection of the levator ani muscles at 3 and 9 o’clock positions, with subsequent suturing in this area to achieve hemostasis.
The scrotal skin flap is tubularized over a vaginal dilator and sutured to the penile skin tube. The skin tube is then everted and inserted into the previously dissected vaginal canal from below. Here, the robotic surgeon grasps it at midline. The anterior portion of the neovagina is reapproximated to the anterior leaf of Denonvilliers’ fascia, using running 3-0 Stratafix suture. The posterior aspect of the neovagina is fixed to the peritoneal reflection overlying the rectum ( Fig. 31.4 ). The lateral peritoneal incisions are closed with a simple running suture, and the apex of the neovagina is closed with a three-point stitch which is run laterally ( Fig. 31.5 ). The neovaginal canal is packed with antibiotic-soaked Kerlix (Cardinal Health, Dublin, OH), ensuring packing to the level of the apex under direct vision. The robot is undocked, and the port sites are closed.
Next, the clitoroplasty is performed. The central portion of the glans is excised, and the lateral wings are deepithelialized. The resultant 2-cm by 1-cm flap of glans is then coned with 3-0 Vicryl to form the clitoris. The glans remains attached to an 8-cm flap of dorsal tunica of the corpora cavernosum and the neurovascular bundle.
The urethra is split at the ventral midline to the level of the decussation of the corpora. The bulbar urethra is widely spatulated, the edges trimmed, and the posterior meatus everted using 3-0 PDS sutures from the 3 o’clock to the 9 o’clock position. Some surgeons may choose to use the excess urethral mucosa to form the vaginal vestibule.
Next, the introitus is created. The central tendon of the bulbar urethra is incised and the bulbar urethra elevated away from the rectum up to the urogenital diaphragm. The rhomboid perineal flap is turned into the canal, and the apex of the flap is sutured to the inferior cut edge of the central tendon. The lateral aspect of the rhomboid flap is sutured to the penile skin flap laterally with interrupted 3-0 Vicryl sutures. To create the labia minora, the midline of the penile flap is marked, the flap is incised over the clitoris and urethral meatus, and the catheter is delivered. The preputial skin is then sutured to the penile skin with 4-0 running chromic. The deepithelized wings of the neoclitoris are buried below the urethral mucosa. To define the labia minora, 3-0 Vicryl horizontal mattress quilting sutures are placed between the base of the preputial skin medially and the natural sulcus in the penile skin laterally. The clitoral hood is further defined by horizontal mattress quilting sutures. The apex of the scrotal flaps is pulled inferiorly and medially adjacent to the rhomboid flap and sutured into place with 3-0 Vicryl.
The lateral edges of the labia majora are closed with 3-0 Vicryl after excess skin is excised medially. The medial edges of the labia minora are closed with 3-0 Vicryl and running 4-0 chromic sutures.
A negative pressure dressing and an external compression dressing are applied to the vulva at the end of the case. The Foley catheter and both external dressings remain in place until postoperative day 5. No drains are left. As with standard vaginoplasty, patients undergoing RPFV must perform lifelong dilation. The additional suture line between the penoscrotal skin flap and the peritoneal flaps creates additional theoretical stenosis risk. The patient is taught how to do so prior to discharge.
Outcomes
The initial series of RPFV from NYU describes results in 41 transwomen. Average operative time was 262 ± 35 minutes, and the average inpatient stay was 5 days. At mean follow-up of 114 ± 79 days after surgery, average vaginal depth and width were measured to be 14.2 ± 0.7 cm and 3.6 ± 0.2. cm, respectively. The average cavity length for traditional PIV in a systematic review by Manrique et al. was found to be 10.7 cm (range: 8.8 to 12.4 cm), with width not reported secondary to underreporting by primary studies. In the RPFV cohort, the peritoneal flap added an average of 5 cm of depth beyond the length of the skin graft. Small areas of granulation tissue and delayed healing at the introitus of the vaginal canal were noted in 20% of patients. These minor wound complications resolved with supportive care and silver-impregnated hydrocolloid dressing changes. All patients reported erogenous sensation postoperatively. This is an improvement over the published finding that, in patients undergoing traditional penile inversion, 89.2% reported erogenous sensation. There were no intraoperative complications, which is in contrast to the traditional technique which appears to carry a 4% to 5% bleeding risk and 2% rectal perforation risk. In an update on the NYU cohort, the rate of intra-abdominal complications was found to be just 2.2%.
These results are largely corroborated by a small series from the University of Illinois at Chicago which reports on a cohort of 11 patients undergoing RPFV with both the da Vinci SP and Xi platforms. Of note, this cohort includes not only patients undergoing primary GAS but also included patients with vaginal stenosis after primary GAS and those with congenital vaginal hypoplasia. Mean operative time was 267.2 ± 85.9 minutes. Initial postoperative mean vaginal depth was 13.9 ± 0.5 cm. Mean length of stay was 5.2 ± 0.6 days. Thirty-day readmission rate was 18% with one patient (9%) requiring surgical revision of the neovagina.
Robotic peritoneal flap revision
Peritoneal flaps may also be used in patients who have undergone prior PIV and subsequently suffer from vaginal stenosis. Ports are placed and peritoneal flaps are raised as in a primary RPFV. Prior to initiating the robotic portion, the vaginal mucosa is stained with methylene blue to assist with identification. The peritoneum is incised underneath the seminal vesicles and Denonvilliers’ fascia opened until the apex of the neovagina is visualized by the robotic surgeon with the assistance of a dilator placed into the stenosed canal. The robotic surgeon dissects down onto the dilator and, once inside the cavity, excises scar tissue laterally as needed to accommodate a 38-mm dilator. The peritoneal flaps are then sutured to the apex and closed as in a primary RPFV ( Fig. 31.6 ). Postoperative care is similar. In a study of 24 patients with stenotic neovaginas undergoing revision RPFV, at mean follow-up of 410 days, vaginal depth and width measured 13.6 and 3.6 cm, respectively. None of these patients had significant intraoperative or postoperative complications.
