End-to-End Anastomotic Urethroplasty Outcome in Anterior and Posterior Traumatic Urethral Stricture: A Single-Center Experience

1. INTRODUCTION

Traumatic urethral stricture is devastating long-term morbidity for men as it lowers the quality of life [1, 2]. In Indonesia, traumatic urethral stricture accounted for most cases of urethral stricture due to massive traffic accidents annually [3]. This is quite the opposite of industrialized countries where iatrogenic, due to instrumentation and catheterization, made a big proportion [1-4]. There are numerous surgical options for urethral stricture, but no particular procedure is ideal in every circumstance. Several factors, such as the length and location of the stricture, the condition of the fractured pubic bone segments, and the patient's age and general health, determine which surgical procedure to employ [5, 6]. There is ongoing controversy surrounding the selection between end-to-end anastomosis urethroplasty and free graft one-stage urethroplasty techniques. However, if appropriately indicated, end-to-end anastomotic urethro- plasty is anticipated to have a high long-term success rate, as no alternative is as effective as the urethra itself. Some evidence suggests performing end-to-end anastomotic urethroplasty in short anterior urethral stricture. To date, some authors also provide a promising patency rate in posterior strictures [7]. The outcome of end-to-end anastomotic urethroplasty is varied across studies, and very limited from the population of Southeast Asia. We conducted this study to describe the outcome of end-to-end anastomotic urethroplasty in anterior and posterior urethral stricture in our population.

2. MATERIALS AND METHODS

A retrospective study was conducted on all male adults (aged >18 years old) with traumatic urethral stricture who underwent end-to-end anastomotic urethroplasty from January 2015 to December 2021 at a national reference hospital in Indonesia (Fig. 1). All traumatic urethral strictures due to external trauma (straddle and pelvic injury) were included. Preoperative diagnosis was determined by retrograde urethrogram or bipolar urethro- cystogram through suprapubic cystostomy (SPC). Patients with incomplete data, iatrogenic-related strictures, and hypospadias were excluded. Patients with less than 12 months of follow-up were also exempted from the study. Approval from the institution's ethical research committee was obtained through approval number KET-70/UN2. F1/ETIK/PPM.00.02/2022 and protocol number 22-01- 0077. Written informed consent was obtained from patients before they underwent the surgery. A compre- hensive clinical evaluation was performed to define the strictures, including a thorough medical history and physical examination, uroflowmetry, and a retrograde urethrogram. After data screening, the data were divided into anterior and posterior strictures.

3. RESULTS

From January 2015 to December 2021, 74 male patients with traumatic urethral stricture underwent end-to-end anastomotic urethroplasty in our center. Of those patients, there were only 50 with completed baseline data included in the study. The overall mean age was 42.06 (SD 12.4; 95% CI) years old, with an overall median follow-up of 21(12-77) months. The overall median operating time was 180(80-360) minutes, while the overall median blood loss was 200(50-1300) mL. The demographics and clinical information of the cases were summarized in Table 1. The cases were mostly total obliteration (64%), primary cases (82%), caused by pelvic injury (64%), done without ancillary maneuvers (68%), and located in the posterior part of the urethra (62%). The overall restricture rate in our study was 36%. The majority of procedures were performed by a consultant, accounting for 84% of cases, whereas the reported rate of complications was 18%. A significant association with restricture rate was found in the BMI category (p = 0.041) and etiology (p=0.03). The included cases were then divided into anterior and posterior strictures. The characteristics of the anterior and posterior strictures were respectively described in Table 2. The anterior strictures comprised 19 patients with an overall restricture rate of 21.1%. The strictures were mostly short (73,7%), total obliteration (63,2%), and caused by straddle injury (63.2%). Of the 31 patients in the posterior strictures, the overall restricture rate (45.2%). The strictures were mostly long (54,8%), total obliteration (64,5%), and caused by pelvic injury (80,6%). The mean surgery time in anterior stricture was 135(80-290) minutes, while in posterior stricture was 180(100-360) minutes. Ancillary maneuver in the posterior strictures was done in 45.2%, while in the anterior strictures was only 10 percent. The restricture rate in redo end-to-end anastomotic urethroplasty was also higher in the posterior strictures (35.7% vs 25%). The reported complications from the patients were erectile dysfunction (2 patients), stress incontinence (2 patients), and penile shortening (1 patient).

4. DISCUSSION

An ideal surgery of urethral stricture should remove the strictured urethra and reattach the ends without introducing foreign tissue. This is precisely what is accomplished with excision and primary anastomosis [7]. The constraint is influenced by the elasticity of the mobilized, healthy urethra after the stricture is removed. The elasticity of the anterior urethra is sufficient to allow for a 2-3 cm length span. While defects measuring 7-9 cm in length can be restored in the posterior urethra by employing ancillary maneuvers to achieve the desired tension-free anastomosis [8, 9]. Across studies, end-to-end anastomotic urethroplasty is considered a preferred therapeutic option for small strictures, particularly those located in the anterior (bulbar) region. However, this procedure is unsuitable for pendulous stricture because it may induce excessive shortening and ventral curvature of the penis. Our study showed an overall restricture rate in traumatic urethral stricture of 36%, significantly associated with etiology and BMI (p<0.05). The success rate was comparable to other studies. Furthermore, we describe the outcome of anterior and posterior strictures after the procedure in traumatic urethral stricture patients.

Our study demonstrated the restricture rate is quite high in the posterior urethral stricture. The lower success rate in posterior stricture was associated with many related factors. The mechanism of trauma as etiology was thought to affect the restricture rate according to the complexity. The external trauma mechanism caused by pelvic injury disrupted the bulbomembranous junction. According to Casselman and Schillinger's theory, the urethra is injured in major pelvic fracture cases when the pelvic ring is compressed laterally, increasing the antero-posterior diameter, superior bladder displacement, and urethral stretching and avulsion follow [10]. A study by Fu et al. [11] also showed that strictures closer than 3 cm to the bladder neck were predictors of poor prognosis. These kinds of strictures frequently necessitate more complicated surgery and carry a greater chance of failure. However, our results showed that the restricture rate of end-to-end anastomotic after redo urethroplasty is similar between the anterior and posterior strictures. As scarring and low tissue vascularity, recurrent urethral strictures provide surgical difficulties [12].

We found no significant association between age and restricture rate. However, Davenport et al. [13] reported that men under 40 had better outcomes after urethroplasty than older men because they had fewer comorbidities predisposing them to impaired vascularity and tissue healing than older men. Testosterone level was also believed to be related to restricture in older age. After age 30, testosterone levels begin to decline at a rate of 0.4% to 2% per year [14-16]. Men with reduced amounts of testosterone in their bloodstream may experience a decline in the blood vessel density inside the urethral and corpus spongiosum tissue. This can be attributed to a drop in the expression of AR (androgen receptor) and TIE-2, a receptor for angiopoietin 1 and involved in angiogenesis mediated by AR. In contrast, studies conducted by Barbagli et al. [17] and Santucci et al. [18] revealed comparable outcomes for younger and geriatric patients. Therefore, the success rate of end-to-end anastomotic bulbar urethroplasty is not solely influenced by patient age and should not be considered when making decisions on the implementation of these procedures.17,18 Although older men are more likely to have multiple comorbidities, their eligibility for urethroplasty should be based on their overall health, not their age [19].

In our study, BMI is a significant factor in restricture occurence. A Cut-off of 23 kg/m2 was used based on the WHO classification for the Asia Pacific population. A higher restricture rate was associated with higher BMI. This result was consistent with a prior investigation by Breyer and colleagues [20]. They found the patients with overweight (25-30 kg/m2) and (30-35 kg/m2) BMI were more likely to experience stricture recurrence than those with a normal BMI between 0-25 kg/m2 and individuals with a BMI of 35 kg/m2 or greater. The precise mechanism by which obesity increases the risk of postoperative complications is unknown and probably multifactorial [21]. Several studies have demonstrated plausible mechanisms, including low-grade inflammation, impaired collagen regeneration, and vascular insuffi- ciency. Inflammation is essential for the development of urethral stricture [22]. In addition, obesity is associated with impaired immune function, which may contribute to the higher incidence of surgical site infections observed in obese patients [23]. According to a study conducted by Elliott et al. [24], both obesity and age were significant determinants of the treatment for urethral stricture. There is debate about whether greater stricture rates in obese individuals are a result of technical problems or whether obesity has an influence on wound healing [25]. Posterior urethral surgery necessitates a high level of expertise and a thorough understanding of the relevant organs' specific anatomical and functional attributes beyond that required in any other segment of the urethra [26].

In our study, there was no correlation between previous urethral instrumentation and the incidence of restricture. There were contradictory findings regarding the impact of prior urethral instrumentation, such as internal urethrotomy, on the efficacy of urethroplasty. According to Roehrborn et al. [27], prior urethral intervention reduces the efficacy of end-to-end anas- tomotic urethroplasty. Similar to this result, Breyer et al. [28] determined that endoscopic treatment failure was a predictor of urethroplasty failure. It is hypothesized that previous DVIU for traumatic posterior urethral injuries will extend the inflammatory process along the already injured tissue, making urethroplasty difficult in the future.19,28 Nonetheless, according to a study by Barbagli et al.17, the prior failure of urethrotomy does not affect the long-term efficacy of bulbar urethroplasty.

Table 2 shows restricture rate is lower in the long anterior group . However, this might be due to a discrepancy in the number of subjects in short and long stricture. Restricture rate in the posterior group is quite similar between short and long stricture. Due to the lengthier stricture length and more complex surrounding structures, ancillary maneuvers were performed more often in the posterior strictures in this study. Longer urethral defects in posterior strictures necessitate a complex perineo-abdominal transpubic approach for adequate exposure. Furthermore, pubic symphysis resection makes the tension between the anterior and posterior urethral anastomoses decrease significantly while the pelvic ring maintains its integrity [9].

Post-operative erectile dysfunction, penile shortening, and incontinence were common complications after urethroplasty. We reported a few cases of those complications based on documented data. The number should be higher as the patient-reported outcome was established in our hospital. However, those with complications did not get any further treatment as they were satisfied with spontaneous voiding. Penile shortening was reported to occur up to 30% in several studies, especially in anterior strictures. Post urethroplasty stress incontinence occurred in less than 10%. The incidence of erectile dysfunction following urethroplasty occurred up to 50% [7, 9]. It appears that the majority of men with erectile dysfunction have it as a result of the pelvic fracture itself. Cavernous nerves and branches of the internal pudendal artery are hypothesized to supply the corporeal bodies via the urogenital diaphragm and are situated in close proximity to the apex of the prostate. A pelvic fracture, specifically pubic symphysis diastasis, caused injury to these neurovascular bundles [9].

This research has several limitations. Due to inadequate documentation, we did not analyze long-term complications such as incontinence, erectile dysfunction, and penile shortening after the procedure. Postoperative uroflowmetry was unidentified in most patients, so the objective parameter was missing. Second, this retrospective study was conducted at a single facility and may not accurately represent the urethral stricture patient population or treatment patterns across the nation. Nonetheless, we accomplished our objective of describing the outcomes of anterior and posterior traumatic strictures after urethroplasty. A prospective, multi-institutional investigation would be useful for validating our findings. Due to inadequate documentation, our study only included a small number of samples; this could be a contributing factor to the insignificant associations. Due to the lack of evidence regarding the comparison of anterior and posterior urethral stricture outcomes, we provided only a general explanation of each factor.

Despite those limitations, our study is the first in Indonesia, a developing country with abundant traffic accidents, to describe the outcome of end-to-end anastomotic urethroplasty of traumatic urethral strictures with a moderately long follow-up period. Thus, a further multicenter prospective study on a large number of patients with multivariate analysis or a systematic review and meta-analysis across available studies is recom- mended to investigate the outcomes after end-to-end anastomotic urethroplasty.

CONCLUSION

The overall restricture rate after end-to-end anastomotic urethroplasty in traumatic urethral stricture was 36%, a higher restricture rate was found in posterior traumatic stricture. BMI and etiologies were associated with restricture occurrence. The present study may suggest end-to-end anastomotic urethroplasty to be performed in traumatic urethral strictures with potential durable patency if appropriately done. End-to-end anastomotic urethroplasty in partial anterior stricture in this study showed the lowest restricture occurrence.

AUTHORS’ CONTRIBUTION

It is hereby acknowledged that all authors have accepted responsibility for the manuscript's content and consented to its submission. They have meticulously reviewed all results and unanimously approved the final version of the manuscript.

REFERENCES