Female urethral stricture: techniques for reconstruction

Conservative management

Minimally invasive treatment for FUS remains the most popular among urologists. Both urethral dilation (UD) and direct vision internal urethrotomy are the available conservative options. According to a 2006 British Survey, 69% of urologists were still regularly practicing UD^[17]; these practice patterns may have changed over the past 15 years favoring surgical intervention. Furthermore, a majority of urologists believe that the first intervention for female urethral stricture should be urethral dilatation^[18], a treatment option supported by recent guidelines^[8].

Although easy to do and relatively low risk, judicious use of UD is advised. Santucci et al.^[19] reported that only 40 patients out of a population of 1.2 million with urethral stricture had undergone reconstructive surgery. This not only resulted in deterioration of patients’ health and quality of life but also resulted in increased health costs with $61 million/year spent on female urethral dilation.

Data are limited to retrospective series, small patient populations without adequate long-term follow-up. UD overall success is noted to be between 47%-49%^[4,20], with success defined as the lack of need for further intervention. These numbers parallel what is seen in male patients as well regarding endoscopic management of urethral strictures. Mean time to failure with UD was 12 months^[21]. In our practice, we follow the same principle as in male patients with no more than one attempt of UD per patient given the poor outcomes of repeated dilations (30%), unless the patient is not a surgical candidate^[22]. Spilotros et al.^[23] reported a low success rate with one UD procedure, and half of those patients required an additional dilation. Some authors reported a 67%-68% success rate with UD, but this may be attributed to a shorter follow-up period^[24,25].

With the increasing interest in this uncommon problem, there has begun a paradigm shift that reflects different training, and more surgeons are choosing to abandon the practice of serial dilations in favor of performing definitive reconstructive repairs. Table 1 summarizes available original articles with outcomes for women undergoing urethral dilation for urethral stricture over the last ten years. The mean success rate in these studies was 54.4% at a mean follow-up of 34.1 months^[21-25].

Definitive management

It is important to distinguish between conservative vs. definitive treatment for FUS. As discussed earlier, serial urethral dilation is an acceptable option for managing symptoms, but its high failure rate makes it a substandard choice when considering definitive treatment. Furthermore, since there has been a growing interest in the management of this rare pathology, some reconstructive urologists suggest that primary urethroplasty can be considered a first-line option for FUS treatment^[26].

The goals for female urethral reconstruction are to restore function, urinate without obstruction, maintain continence, prevent vaginal voiding, and maintain sexual function. Although these goals are considered an ideal scenario, there is a dearth of literature considering all five variables when analyzing outcomes. Alternatives when considering a surgical approach are an augmented urethroplasty with a flap or graft vs. a non-augmented urethroplasty: excision and primary anastomosis (EPA) or meatoplasty. The choice is based upon stricture characteristics and surgeon preference as there is insufficient evidence to support one technique over another, which is reflected in the European Guidelines^[8].

Reports on EPA in female urethral strictures are few. However, it may be recommended in strictures due to pelvic fracture and under a sine qua non condition that stricture is short and in the proximal or mid urethra. In addition, there are reports of robotic-assisted techniques being utilized for patients with proximal short traumatic stricture.

In cases where there is an isolated distal urethral stricture, meatoplasty should be considered. This usually occurs after traumatic instrumentation, radiation therapy to the pelvis, and more commonly in postmenopausal patients with vulvar and vaginal atrophy. Care needs to be taken not to make the incision too ventral to prevent vaginal voiding. Rosenblum et al.^[27] suggest that circumferential, distal urethrectomy and advancement meatoplasty work best for treating these distal strictures. This is also the preferred technique of the authors.

Flaps

The utilization of tissue flaps for reconstruction is one of the oldest tools available for reconstructive surgery, and it remains a valid option when considering approaches for urethroplasty in women. Various authors have published their results using vaginal flaps, with a success rate that ranges between 60%-100% according to our literature review^{[21,24-26,28-31]} [Table 2]. However, there is wide variation, likely due to several factors, including a range of follow-up (12 to 72 months), varied etiology, and surgical technique.

Flaps can be obtained from vaginal (U-shaped or C-shaped), labial, or vestibular tissue, and their versatility allows them to be placed either in a ventral position (vaginal, labial tissue) or dorsally (vestibular tissue). The anterior vaginal wall flap and lateral vaginal wall flap techniques have proven safety and efficacy, although some authors suggest that the latter is superior since it does not result in a retrusive meatus and an inward urinary stream^[28]. On the contrary, Simonato et al.^[29] reported no complications with the lateral flap technique.

The advantages of using local flaps rely on their robust vascularity and adequate mobility characteristics along with relatively low morbidity. Acceptable complication rates were reported with these procedures, with only 3.7% de novo stress urinary incontinence (SUI) noted^[4]. Furthermore, in patients with concomitant SUI, a pubovaginal sling could be placed without major impediments^[25,30]. In one series, a sling was necessary due to persistent SUI 12 months after surgery^[31].

Some authors opine that patients who required intermittent self-catheterization for a short period after urethroplasty should not be considered a failure^[32]. In addition, it is debatable whether estrogen status may affect local tissue use. Finally, an important limitation of flap utilization is local tissue health. Flaps should not be used for patients with lichen sclerosus or other conditions such as radiation that result in unhealthy tissue.

Grafts

Graft augmentation urethroplasty has gained popularity, both in male and female patients. Free grafts may be obtained from local tissue (vaginal, labial) and oral mucosa (buccal, lingual). Tables 3 and 4 compile the past 10-year-period study outcomes of local and oral grafts, respectively^{[2,23,25,26,30,33-44]}. Vaginal or labial graft augmentation had an 80%-87% mean success rate, whereas oral mucosa grafts’ mean success rate ranged between 89%-94%^[4,20]. With an average follow-up of over 18 months, mean success closely matches that of patients who underwent flap urethroplasty.

Using local tissue to harvest graft is not advised in patients with LS. Also, care needs to be taken when considering estrogen-sensitive local grafts in post-menopausal patients. Hormone creams may be helpful when using local grafts in these women, as suggested by Romero-Maroto et al.^[28]. Some authors advocate the use of labia minora grafts^[33,34], whereas others prefer harvesting a vaginal mucosa graft^[35,36]. Data reflects that both techniques have proven to be equally efficacious with similar surgical outcomes.

On the other hand, buccal mucosa grafts have gained popularity, at least in part because of their versatility. These are easy to harvest, with low donor site morbidity. They are easy to handle, have good graft take, and minimal contracture; these unique characteristics make them an ideal substitute tissue for urethroplasties. Sharma et al.^[37] presented their work using lingual mucosa grafts with acceptable results compared to the available literature. In our experience, we only use lingual mucosa grafts when we have no available healthy buccal mucosa to harvest.

Where to place the graft remains a subject of controversy. There exists a debate regarding a dorsal vs. a ventral approach. The decision to place a ventral graft relies on the presumption that it is an easier dissection and that it would preserve sexual function, although there is one study that showed that sexual function is not affected with dorsal approach and, even more, it documented an improvement in sexual function scores^[38]. In their respective series, none of the authors performing a dorsal approach reported a decrease in sexual function^[39-41]. A dorsal approach preserves ventral tissue planes in case there is a need for a future continence procedure. Additionally, Gomez and Pfeifer^[45] proposed the idea that the dorsal approach may entail a lesser risk of incontinence by preserving ventro-lateral supporting structures. Similar de novo SUI rates were found in both approaches (3.6% with a dorsal approach vs. 5.8% with a ventral approach) in a review by Sarin et al.^[4]. Although it has been suggested that the ventral approach might increase the risk of urethro-vaginal fistula, there is no data available regarding this complication. Coguplugil et al.^[43] suggest that performing a full-thickness vaginal dissection might prevent fistula formation.

Special situations

Within the iatrogenic causes of FUS, extra care needs to be taken with patients who have undergone pelvic radiation. As in their male counterparts, urethral strictures caused by radiation are often more complex to diagnose and treat. These patients may benefit from urodynamic evaluation to better elucidate symptoms when appropriate. There is little data regarding radiated FUS because most authors exclude them from their series. Gomez et al.^[46] report that both of their radiated patients undergoing urethroplasty failed and suggest maximizing a conservative approach with these patients. If local tissue is of poor quality, a Martius flap may be utilized to provide a healthy graft bed.

Patients with urethral stricture and concomitant stress urinary incontinence are rare. In these cases, we advocate performing a continence procedure at the same time as the urethroplasty, or at interval if preferred. In our practice, we treat the stricture with a dorsal buccal mucosa graft urethroplasty, and the stress urinary incontinence with a pubovaginal sling. Martius flap may be utilized if needed.

Some authors suggest that interposition of a Martius flap should be done in all cases when performing a ventral onlay buccal mucosa graft urethroplasty because it provides a healthy vascular base for the graft, prevents urethrovaginal fistula development and provides healthy tissue between the reconstructed urethra and the overlying vagina to facilitate any future surgery for subsequent SUI^[2].

Suprapubic tube placement pre, intra or postoperatively can be considered. In some cases, such as obliterative strictures, particularly in radiated patients, antegrade access is helpful. If the stricture is obliterative, kissing grafts (dorsal and ventral) may be utilized. Lane et al.^[25] reported that 14% of patients undergoing augment urethroplasty required a suprapubic tube placement preoperatively, and 14% of patients intraoperatively. In rare cases, a suprapubic tube placement or formal urinary diversion should be considered the definitive treatment if reconstructive alternatives fail^[8].

Future directions

Although there have been some important advances in the understanding and management of FUS, there is still room for improvement. Data available is scarce and with an overall poor level of evidence. Published studies consist mostly of descriptive, retrospective series or technique papers with a small number of patients. Most of these are single-center with the exception of two multicenter studies^[25,44]. There is a need for long-term randomized, controlled trials comparing different treatments. We also advocate the idea of the creation of an international registry to collect data prospectively for more robust and long-term evidence suggested by Chakraborty et al.^[32]. The recent publication of the European Association of Urology guidelines for the management of female urethral strictures provides a framework for decision making in these cases^[8].

In the future, new technology might play a role in managing FUS disease. Both tissue engineering and drug-coated balloons may be options that will increase our armamentarium. Although more robust data in tissue engineering is found for male patients, there are some ongoing preclinical and clinical studies open on FUS, which hopefully will show good preliminary results in this innovative field^[47]. Drug-coated balloons for the treatment of urethral stricture also showed promising results in male patients with 70% success at 12-month follow-up and is yet to be determined with future studies if it could demonstrate similar efficacy in female patients^[48].