ESGURS: Treatment of anastomotic strictures after phalloplasty

Dr. Wesley Verla Dept. of Urology Ghent University Hospital Ghent (BE)

wesley.verla

@uzgent.be

Prof. Nicolaas Lumen Dept. of Urology Ghent University Hospital Ghent (BE)

nicolaas.lumen@ uzgent.be

Dr. Marjan Waterloos Dept. of Urology AZ Maria Middelares Ghent University Hospital Ghent (BE)

marjan.waterloos@ azmmsj.be

Background

Phalloplasty is considered one of the standard treatment options for transmen, especially for patients desiring both sexual function and the ability to void in a standing position. [1-5] Different techniques for phalloplasty have been described, but all come with significant morbidity. [6] Besides flap complications, the constructed neo-urethra accounts for an important amount of postoperative complications2. The two main problems at this level are urethrocutaneous fistulas, which are reported in up to 75%, and stricture formation, which is seen in up to 58% of patients. [2] These urethral strictures can occur in any segment of the constructed neo-urethra, but most commonly affect the anastomosis between the fixed and pendulous part of the neo-urethra. [1,4]

"Notably, the outcomes of urethral reconstruction in transmen are far worse than the outcomes in cismen."

Anatomy of the neo-urethra after phalloplasty

After phalloplasty, the neo-urethra can be divided into the following parts, from proximal to distal: native urethra, fixed part of the neo-urethra and pendulous or phallic part of the neo-urethra (see figure 1). [1] The native female urethra remains untouched during phalloplasty. The fixed part of the neo-urethra represents the bridge between the native urethra and the pendulous part of the neo-urethra and is generally created by tubularising the vestibular mucosa of the vagina up to the level of the clitoris. The clitoris is then de-epithelialised and tunnelled underneath the pubic fat towards the prepubic area. There it is fixed onto the periost of the pubic bone, at the level where the neophallus is to be implanted later on in the procedure. The pendulous or phallic part of the neo-urethra is constructed by tubularising a skin flap (origin depending on graft harvest site and phalloplasty technique) which is in turn wrapped with the neophallic skin flap. This part of the neo-urethra is later anastomosed with the fixed part of the neo-urethra in an end-to-end fashion. As discussed above, this anastomosis is the most vulnerable for urethral stricture formation, a problem that is likely caused by the fact that this is a mucocutaneous junction, which has a natural tendency to narrow. [1,4]

Treatment options

Despite the high incidence of urethral stricture formation after phalloplasty, data on its management remains relatively scarce, especially when compared to data on cismen. [3,7] The therapeutic options for transmen are similar to the ones for cismen, although they come with worse outcomes, cfr. infra. The least invasive way to treat an anastomotic stricture after phalloplasty is by performing a direct vision internal urethrotomy (DVIU). [8] Lumen et al. described their experience in 22 patients. DVIU was considered successful in 44% of patients after a median follow-up of 51 months. [8] The investigators concluded that a maximum of two attempts with DVIU can be tried with reasonable outcomes. [8]

Anastomotic repair urethroplasty

Alternatively, for isolated, short anastomotic strictures, an anastomotic repair urethroplasty can be performed. [1,4] During this procedure the narrowed segment of the neo-urethra is resected and the pendulous urethra is mobilised as much as possible to create a new tension-free and wellvascularised end-to-end anastomosis (see figure 2). [4] However, unlike the outstanding results in cismen, anastomotic repairs appear to be far less effective for anastomotic strictures after phalloplasty. It shows a 5-year failure-free survival rate of only 47%, almost comparable to the results of DVIU. [4] However, in the patient series of Verla et al., almost half of the patients had a complete obliteration (making a DVIU impossible) and almost two-thirds of them were pre-treated with one or more endoluminal treatments, so these patients were probably a priori more challenging to treat. [4] In that same report, the outcomes of anastomotic repair were also stratified according to stricture length, which showed a steady decline in success rate with increased stricture length. [4] The investigators concluded that an anastomotic repair only leads to reasonable outcomes in anastomotic strictures up to 2 cm. [4]

For very short anastomotic strictures with little fibrosis, a Heineke-Mikulicz stricturoplasty can be performed as well. This is described by Lumen et al., although in their series only one patient was treated as such. [1]

What about grafts

And what about grafts? In 2016, Wilson et al. described a ventral onlay buccal mucosa graft augmentation urethroplasty where the graft was placed ventrally on the anastomotic stricture in three patients. [9] In all cases, they harvested an additional scrotal or medial thigh fasciocutaneous flap to reinforce the vascular supply of the graft. This led to a success rate of 100%, albeit after a mean follow-up of only 9 months. [9] More recently, Schardein et al. published a double-faced graft technique [10], based on the Palminteri technique used in cismen [11], where they do a dorsal inlay and a ventral onlay of buccal mucosa with a Martius flap to reinforce the ventral graft. They reported a 75% success rate after a mean follow-up of 31 months. [10]

For patients in whom the vascular supply of a free graft remains an issue, augmentation with a pedicled skin flap might be an option, as these flaps bring their own vascularisation in the pedicle. [1]

Two-stage procedure

Alternatively, a two-stage procedure may be carried out. In cismen, this option is increasingly reserved for patients with very poor local tissue conditions and very dense fibrosis, especially given the outstanding results of one-stage urethroplasties. [1,7] In transmen, however, the scenario is completely different. Patients often present with very challenging tissue conditions, even early in the course of stricture disease. This might be a reason to lower the threshold towards working in two or more stages, where the urethra is marsupialised in the first stage (see figure 3) and later closed around a catheter with or without graft augmentation in the next stage. [1,4] The only data to support this is given by Lumen et al. who reported an overall success rate of 70% (not specifically for anastomotic strictures) after two-stage urethroplasty with a mean follow-up of 39 months. [1]

Finally, a definitive perineal urethrostomy always remains an option in the treatment cascade. [1] This is generally well accepted by older or multi-operated cismen who accept to void in a sitting position. However, the transmasculine population is often far younger and for them, voiding in a standing position has high priority. Nonetheless, in selected patients, this may be preferred over another surgical attempt to restore urethral patency up to the level of the meatus.

Differences between cis- and transmen

Notably, the outcomes of urethral reconstruction in transmen are far worse than the outcomes in cismen. [3,7] This can be explained by a multitude of factors, all related to the differences between a neophallus and a native penis. First of all, the environment to perform a urethral reconstruction in is much poorer after phalloplasty, because the tissues are heavily operated and traumatised which leads to a tenuous vascularisation. Second, the high postoperative complication and reoperation rate after phalloplasty leads to increased fibrosis and a diminished vascular supply of the local tissues. Third, a neo-urethra is far less mobile than a native urethra, especially at its bulbar segment. This in turn generates problems to create a tension-free anastomosis or to mobilise the urethra sufficiently to perform, for example, a dorsal onlay free graft urethroplasty. Also, the ventral coverage of the neo-urethra and the anastomotic site is often very thin and poorly vascularised which leads to an increased risk of fistula formation and graft failure when put on ventrally without the support of local tissue flaps.

Figure 1: Anatomy of the neo-urethra Adapted from Lumen et al. [1]

"All recommendations on the treatment of urethral stricture disease in transmen are based on a low level of evidence, since only retrospective case series have been published so far."

Given these challenging conditions, treatment of transmen with urethral stricture disease should only be performed by experts with the versatility to adapt their surgical strategy to the pre- and peroperative findings of each individual patient.

Future directions

All recommendations on the treatment of urethral stricture disease in transmen are based on a low level of evidence, since only retrospective case series have been published so far. [3] Prospective, comparative studies (ideally randomised controlled trials) with data on surgical and functional outcomes are needed to better understand what works for which patients and to make strong clinical practice recommendations.

Key points

• Strictures can occur in any segment of the neo-urethra, but most commonly affect the anastomosis between the fixed and pendulous part of the neo-urethra. • Different treatment options exist, albeit with strikingly poorer results than in cismen. • Given the challenging local tissue conditions in these patients, the threshold to perform a two-stage procedure should perhaps be lower. • Treatment of transmen with urethral stricture disease should only be performed by experts. • Prospective, comparative studies are needed to better understand what works for which patients and to make strong clinical practice recommendations.

Figure 3: Appearance after stage one of a two-stage urethroplasty for an anastomotic stricture

References

1. Lumen N, Monstrey S, Goessaert AS, Oosterlinck W,

Hoebeke P. Urethroplasty for strictures after phallic reconstruction: a single-institution experience. Eur Urol. 2011 Jul;60(1):150-8. 2. Nikolavsky D, Yamaguchi Y, Levine JP, Zhao LC. Urologic

Sequelae Following Phalloplasty in Transgendered

Patients. Urol Clin North Am. 2017 Feb 1;44(1):113-25. 3. Riechardt S, Waterloos M, Lumen N, Campos-Juanatey F,

Dimitropoulos K, Martins FE, et al. European Association of Urology Guidelines on Urethral Stricture Disease Part 3: Management of Strictures in Females and

Transgender Patients. Eur Urol Focus. 2021; 4. Verla W, Hoebeke P, Spinoit AF, Waterloos M, Monstrey S,

Lumen N. Excision and Primary Anastomosis for

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Transmasculine Patients. J Clin Med. 2021 Sep 1;10(17). 6. Boczar D, Huayllani MT, Saleem HY, Cinotto G, Avila FR,

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Zhao LC. Fasciocutaneous flap reinforcement of ventral onlay buccal mucosa grafts enables neophallus revision urethroplasty. Ther Adv Urol. 2016 Dec 1;8(6):331-7. 10. Schardein J, Beamer M, Hughes M, Nikolavsky D.

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Urology. 2020 Sep 1;143:257. 11. Palminteri E, Berdondini E, Shokeir AA, Iannotta L, Gentile

V, Sciarra A. Two-sided bulbar urethroplasty using dorsal plus ventral oral graft: urinary and sexual outcomes of a new technique. J Urol. 2011 May;185(5):1766-71.