A review of management options for vesicourethral anastomotic stenosis and the emergence of robotic reconstruction

Abstract

Vesicourethral anastomotic stenosis (VUAS), a sequela of radical prostatectomy, is among the most complex conditions managed by reconstructive urologists. As a distinct entity from bladder neck contracture, VUAS can be managed endoscopically or with reconstruction. There is a paucity of higher-level evidence and head-to-head comparisons between VUAS management options. Interpretation of existing studies is further complicated by variations in diagnostic staging of VUAS, definitions of recurrent VUAS, and criteria for post-procedural success. Multiple endoscopic approaches are available including dilation, transurethral incision, transurethral resection, intralesional injections, and endoscopic urethroplasty. Classically, reconstruction for VUAS is offered after a single failed attempt at endoscopic management. Reconstructive options include transperineal reconstruction, open abdominopelvic reconstruction, and robotic-assisted surgical techniques. In recent years, several advances in reconstruction have developed into minimally invasive techniques using multi- and single-port robotics. Early outcomes of robotic reconstructive surgery demonstrate excellent rates of treatment success and, compared to open approaches, notably lower rates of de novo urinary incontinence. Both endoscopic and surgical treatment of VUAS present significant risks of morbidity including the potential need for urinary diversion, therefore appropriate patient counseling and shared decision-making are critical prior to urologic intervention.

Introduction

Vesicourethral anastomotic stenosis (VUAS), which has a reported incidence of 0.2–26% after radical prostatectomy, represents a complex and clinically challenging complication of prostate cancer survivorship (1-3). Although prior studies have generally referred to bladder neck contracture (BNC) and VUAS interchangeably, appreciating BNC and VUAS as distinct conditions is paramount as they differ in etiology and management. VUAS is a narrowing of the anastomosis between the bladder and urethra that occurs after radical prostatectomy (4-7). In contrast, BNC is a narrowing of the bladder neck in patients with a prostate, which most commonly occurs after a bladder outlet procedure.

VUAS may be clinically significant when a patient experiences lower urinary tract symptoms such as weak stream, hesitancy, and straining to void; urinary tract infections; and/or urinary retention due to stenosis that cannot be traversed with a flexible cystoscope (8). Endoscopic treatment is typically favored in patients with VUAS. Current guideline recommendations by the American Urological Association (AUA) support attempting endoscopic management of VUAS with dilation, vesicourethral incision [transurethral incision of bladder neck (TUIBN)], or transurethral resection (TUR) [transurethral resection of bladder neck (TURBN)] (9). The AUA guidelines also support offering open or robotic reconstruction for recalcitrant post-prostatectomy VUAS. The European Association of Urology (EAU) guidelines recommend endoscopic management with dilation or direct vision incision urethrotomy as first line therapy for non-obliterative VUAS (10).

However, in the setting of failed endoscopic management, surgical reconstruction may be necessary as it is considered to be the most definitive treatment option. Traditionally, reconstructive approaches consisted of open abdominal and/or perineal surgical techniques (11). However, open surgical reconstruction of VUAS is challenging and complex as the target anatomy is deep in the pelvis and perineum making exposure difficult; all patients have a re-operative surgical field due to a history of radical prostatectomy; a considerable number of patients additionally have a history of prior pelvic radiation for prostate cancer, which often leads to obliteration of normal dissection planes and impaired vascularity for wound healing; and there is a significant risk of de novo and/or worsening urinary incontinence due to the proximity of the residual external urinary sphincter (EUS). Although the literature regarding robotic VUAS is limited, the robotic modality is well-suited to mitigate some of the challenges associated with VUAS reconstruction as the robotic modality maintains the benefits of minimally invasive surgery such as improved cosmesis, decreased hospital stay, and reduced postoperative pain, and additionally provides surgeons with benefits such as three-dimensional magnified visualization, wristed instrumentation, and integration of near-infrared fluorescence (NIRF) to assess tissue perfusion.

Herein, we review the existing literature regarding VUAS and its management with an emphasis on robotic reconstructive techniques and their outcomes. Given the paucity of literature evaluating outcomes after robotic VUAS reconstruction, we supplement our review of the literature with commentary based on our experience at a high-volume robotic VUAS reconstruction center.

Methods

A literature review was performed using PubMed, MEDLINE, Embase, Web of Science, ClinicalTrials.gov, and the Cochrane Library to identify studies by searching for keywords pertaining to VUAS. Search keywords included “vesicourethral anastomotic stenosis”, “vesicourethral anastomotic stricture”, “vesicourethral anastomotic contracture”, and “bladder neck contracture” in conjunction with “radical prostatectomy”. Studies written in English with patients >18 years met the inclusion criteria. Various study types were included such as clinical trials, prospective/retrospective cohorts, case series, and case reports. Publications that were included in our review featured various topics surrounding VUAS such as epidemiology, pathogenesis, procedural techniques, and treatment-associated outcomes. Studies exclusively investigating BNC in patients with a prostate present and/or no prior history of radical prostatectomy were excluded. An emphasis was placed on studies published within the past 15 years and topics pertaining to robotic reconstructive techniques with surgical outcomes.

Epidemiology

After radical prostatectomy, 88% of VUAS diagnoses occur within 1 year (4). A wide range of VUAS incidence after radical prostatectomy has been reported in the literature ranging from 0.2% to 26% (1-3). However, in the era of robotic-assisted surgery, the incidence of VUAS after radical prostatectomy has generally ranged between 1–2% (12,13) In 2009, Krambeck et al. compared 588 patients who underwent open retropubic radical prostatectomy (RRP) to 294 patients who underwent robotic-assisted radical prostatectomy (RARP). At 1-year follow-up, the authors found VUAS to be more common after RRP than RARP (4.6% versus 1.2%, P<0.018) (14). A similar trend of more frequent VUAS development among RRP patients has been demonstrated in the extant literature (15,16). Alternatively, Breyer et al. examined VUAS rates in 695 patients at a single institution who underwent RRP versus 293 patients who underwent RARP. At 18 months after radical prostatectomy, both surgical approaches demonstrated low rates of VUAS without significant differences (RRP 3%, RALP 1%, log-rank P=0.13) (12). Generally, authors suggested the robotic modality provides enhanced visualization of the deep pelvis and wristed instrumentation which facilitates the surgeon’s ability to perform the vesicourethral anastomosis during radical prostatectomy (14-16).

Over the decades, VUAS pathogenesis has been linked to numerous etiologies and risk factors. According to the EAU Guidelines on Urethral Stricture Update in 2022, well-established risk factors for developing VUAS following radical prostatectomy include higher-grade cancer, larger prostate volume, coronary artery disease, hypertension, diabetes, prior bladder outlet procedures, non-nerve sparing radical prostatectomy, increased operative time, and vesicourethral anastomotic leak (10,17-19). Several studies investigated additional parameters that potentially place patients at risk of VUAS. Patients experiencing early urinary retention following RARP within 7 days of catheter removal are more likely to develop VUAS (20). Both radiation after radical prostatectomy (21) and salvage prostatectomy have been implicated as risk factors for VUAS formation (22-24). Non-absorbable clip migration or erosion from the previous radical prostatectomy into the vesicourethral anastomosis has emerged as a potential nidus for VUAS (25-28). The suturing technique for vesicourethral anastomosis has also been studied by multiple groups with evidence supporting absorbable continuous running suture use (29-32).

Diagnostic workup

Diagnosis of VUAS is generally prompted in post-radical prostatectomy patients with lower urinary tract symptoms related to emptying and irritative voiding; gross hematuria; and/or acute urinary retention. Currently, there are no specific guidelines to guide diagnostic evaluation for VUAS. Given treatment decision implications, the importance of appropriate diagnostic evaluation cannot be understated. At our institution, we typically perform cystoscopy on all patients to assess the caliber of the lumen and length of stricture, and evaluate for EUS involvement. When it is difficult to assess stricture length, we perform a retrograde urethrogram and/or voiding cystourethrogram. In patients with pubic bone pain and/or a history of urinary extravasation after endoscopic management, we obtain pelvic magnetic resonance imaging to assess for abscess formation and/or pubosymphyseal fistula.

It must be emphasized that we do not perform diagnostic evaluation in patients with an existing indwelling urethral catheter and patients who perform self-catheterization as this may obscure accurate stricture assessment. In patients dependent on urethral hardware, we typically place a suprapubic tube and allow for a period of urethral rest for 4 weeks prior to initiating diagnostic evaluation.

VUAS management options

Endoscopic treatments

Endoscopic treatment is typically considered first-line for patients with VUAS. Importantly, caution is advised when pursuing endoscopic treatments in the irradiated population as complications such as pubosymphyseal fistula have been described (33). There are currently a multitude of endoscopic treatment options VUAS and our review consists of the most commonly utilized techniques:

Dilation

In 1990, the earliest case series on managing VUAS with urethral dilation was presented by Surya et al. (34) Since then, numerous methods have been described ranging from sounds to nephrostomy balloons to the paclitaxel drug-coated balloon (35-37). In 2004, Besarani et al. reported one of the largest experiences with urethral dilation in 48 patients with VUAS after RRP who were generally managed with dilation by Clutton’s sounds up to 26 French. Repeat dilation occurred in 9 (19%) patients. All patients voided well with adequate flow. At 1 year, most patients reported the same quality of life or better and 95% of patients were not requiring pads (35). In 2014, Zhang et al. (36) evaluated the role of nephrostomy balloon dilation in managing VUAS in 40 patients, of whom 3 patients required repeat dilations. Recurrence was defined as max urinary flow rate <10 mL/s. The median pre-dilation flow rate for the cohort was 4 mL/s. At 12-month follow-up, median max flow rate was 19 mL/s and 3 (7.5%) patients had persistent de novo urinary incontinence. Paclitaxel drug-coated balloon dilation (Optilume^®) has been introduced in recent years as a technology for treating anterior urethral strictures and benign prostatic hyperplasia (37,38). By combining balloon dilation with localized delivery of an antiproliferative drug, the thought is that this device may reduce the risk of stricture recurrence. Off-label use has been described in the literature for BNC following TUR of prostate (39). However, no published data is presently available to support the use of this technology in managing VUAS.

TUIBN

Historically, TUIBN has been considered first-line therapy for VUAS (40). TUIBN involves multiple longitudinal incisions in various locations along the circumference of the VUAS using the Collin’s knife or urethrotome to allow for passage of the cystoscope (40). Numerous studies have evaluated outcomes for VUAS treated with TUIBN (41-43). Incisions are classically performed at the 3 and 9 o’clock positions of the bladder neck. The 6 and 12 o’clock positions of the bladder neck should be avoided given that incisions in these locations may be associated with rectal injury/fistula and pubic osteomyelitis, respectively.

In 2021, Shinchi et al. reported retrospective outcomes in 43 patients with non-obliterative VUAS who underwent TUIBN with deep lateral incisions at the 3 and 9 o’clock positions. Surgical success was defined as not requiring re-treatment or self-dilation. At median follow-up of 43 months, 35 (81.4%) patients met surgical success criteria while the remainder required repeat treatments. Notably, 37 (88.1%) patients developed urinary incontinence postoperatively and 7 (16.7%) patients underwent subsequent artificial urinary sphincter (AUS) placement. No differences in TUIBN outcomes were appreciated in cases of prior radiation (P=0.89) or VUAS treatment (P=0.71). However, the previously irradiated group consisted of only 6 (14%) patients (41).

Veerman et al. more closely examined the relationship between radiation and outcomes in a retrospective cohort of 90 patients with VUAS after RARP undergoing TUIBN. Patients were categorized into four groups: (I) RARP-only/no radiation (n=52); (II) TUIBN before salvage radiation (n=14); (III) TUIBN after salvage radiation (n=14); and (IV) TUIBN after salvage prostatectomy (n=10). Reported outcomes were VUAS recurrence rate, transurethral micturition, and continence rates after TUIBN. At median follow-up of 32 months, patients with any radiation had higher rates of recurrent VUAS and urinary incontinence. The VUAS recurrence rate for RARP-only patients was 12% compared to irradiated groups 2–4 who witnessed VUAS recurrence rates of 57% (P=0.01), 29% (P=0.39), and 50% (P=0.06), respectively. Severe urinary incontinence rates (>1 pad per day) followed a similar trend among RARP-only patients (6%) compared to irradiated groups 2–4 (16%, 10%, and 29%; P=0.2). Of note, fistulae between the bladder neck and pubic os leading to pubic osteomyelitis occurred in one patient with TUIBN after salvage radiation and one patient with TUIBN after salvage prostatectomy (42).

TURBN

Treating VUAS with TURBN involves complete circumferential bladder neck resection, which has generally been discouraged due to concerns for worsening re-stenosis from an exacerbated healing response compared to TUIBN (40). Nonetheless, outcomes studies have investigated the viability of this approach (43-45).

In 2021, Pfalzgraf et al. reported a multi-institutional experience of TURBN versus TUIBN treatment outcomes for VUAS predominantly following RRP. Overall, 103 patients with VUAS underwent endoscopic management: 65% TURBN and 35% TUIBN (lateral incisions). Among VUAS patients undergoing TURBN, 36% had prior radiation, 37% were treatment naïve while 63% had undergone prior endoscopic treatment. For TUIBN, 39% had prior radiation, 58% were treatment naïve while 42% had undergone prior endoscopic treatment. The authors sought to identify predictors of VUAS recurrence and de novo incontinence. Recurrence was defined as needing instrumentation or additional procedures. At median follow-up of 17 months, while TUIBN demonstrated lower rates of a VUAS recurrence, no significant difference was identified for time to recurrence for TURBN versus TUIBN (63% versus 47%, respectively; P=0.1). Similarly, no differences were observed for primary versus re-treatment of VUAS and prior versus no radiation. No differences in de novo incontinence were observed based on radiation status and prior endoscopic treatment. However, de novo incontinence postoperatively was more frequent after TUIBN compared to TURBN (31% versus 12%; P=0.032) (43).

Intralesional injections

Mitomycin C (MMC), an antineoplastic agent, is also recognized as an antiproliferative agent through inhibition of scar formation via DNA crosslinking and blockade of protein synthesis which ultimately reduces collagen deposition (46-48).

In 2015, the Trauma Urologic Reconstructive Network of Surgeons (TURNS) group presented a multi-institutional experience of TUIBN + MMC in 55 patients with BNC/VUAS. Prior treatment had occurred in 80% of patients and 25% had prior radiation. Among the cohort, 33 (60%) patients had VUAS following RRP/RARP. Various surgical techniques were used to make 3–4 deep incisions: cold knife incision (55%), Collins knife with electrocautery (29%), and TUR of scarred tissue (16%). MMC injections followed incision at concentrations of 0.1–1 mg/mL. At median follow-up of 9.2 months, after a single TUIBN + MMC, 32 (58%) patients had resolution of BNC. At median 3.7 months, recurrences occurred in 23 (42%) patients. Considering patients who underwent repeat TUIBN + MMC, the overall cohort success rate was 75%. Adverse events occurred in 4 (7%) patients. Three patients had prior radiation for prostate cancer and developed: osteitis pubis within 2 months (two patients), both of whom were treated with cystectomy and urinary diversion, and rectourethral fistula with bladder floor necrosis (one patient) at 3 months requiring fecal diversion and pending urinary diversion at the time of publication. The final adverse event was bladder necrosis involving the bladder neck, floor, and trigone resulting in pain which resolved at 6 months. Of note, the patients who experienced these adverse events received doses of MMC ranging from 2–4.5 mg and 3 patients underwent TUIBN with electrocautery. In conclusion, the authors suggested that the benefit of TUIBN + MMC may be limited while being faced by a 7% rate of adverse events (49).

In 2021, Rozanski et al. examined the impact of prior radiation on intralesional injection outcomes in 86 patients with BNC/VUAS. The authors performed tri/quadrant cold knife incisions avoiding the anterior position, followed by injections of 0.3–0.4 mg/mL of MMC at each incision site. Among the cohort, 58 (67%) patients had VUAS, 19 (22%) patients had VUAS with history of prostatectomy and radiation, and 78 (91%) patients had failed at least one prior urethrotomy. Outcomes were reported for the combination of BNC/VUAS patients, with 56 (65%) patients experiencing anatomic success after initial procedure. At median follow-up of 21.1 months, success for the cohort after ≥3 procedures was 90%. The authors also found non-radiated BNC/VUAS patients to have significantly higher success rates compared to irradiated BNC/VUAS (94% vs. 75%; P=0.04). Two (2.3%) patients underwent urinary diversion at a later time (50).

The role of intralesional steroid injections for VUAS had been explored (51-54), as anti-fibroblastic steroid properties have been hypothesized to mitigate hypertrophic scar formation (55). Neu et al. evaluated 18 patients with recalcitrant VUAS for whom cold knife incisions were performed at 3, 9, and 12 o’clock positions with subsequent lateral injections of 4 mg/mL triamcinolone. The cohort had a median of five failed prior procedures per patient. Post-triamcinolone injection success was evaluated at the 3-month follow-up cystoscopy as the ability to pass a 17 French flexible cystoscope beyond the treated stenotic segment. At mean 16.3 months after steroid injection, the success rate was 83% while 5 (28%) patients experienced treatment related complications including urinary extravasation (53).

In 2022, Shaw et al. reported their experience in 20 patients with recurrent VUAS who underwent four-quadrant plasma button TUIBN followed by injection of 2.5 mL of 4 mg/mL triamcinolone injection. Posterior incisions were avoided in patients with prior salvage radiation (8 patients/40%). Success criteria consisted of bladder neck patency at 3- and 6-month cystoscopy and not requiring re-treatment. At median follow-up of 40 months, the authors reported a 75% success rate with a single treatment of TUIBN + triamcinolone. VUAS recurrence occurred in 5 (25%) patients. When including patients who underwent repeat treatment with TUIBN + triamcinolone, cumulative success rate increased to 85%. No de novo urinary incontinence occurred. One adverse event occurred involving a rectourethral fistula which healed spontaneously in a patient with an obliterated VUAS who previously had a rectal injury during radical prostatectomy (54).

Endoscopic posterior urethroplasty

In recent years, novel techniques involving endoscopic transurethral reconstruction have emerged as potential treatment options for VUAS. In 2021, Abramowitz et al. (56) reported a retrospective experience of 19 patients with either VUAS/BNC who were treated with an endoscopic technique demonstrated by Warner in 2020 (57). For VUAS, the stenotic segment is dilated to 24 French with S-shaped dilators (Cook Medical, Bloomington, IN, USA) followed by 3 and 9 o’clock incisions with electrocautery until the lumen appears 30 French in caliber. Then, the technique involves cystoscopic incision of the scarred segment in sequence with transurethral use of a laparoscopic suturing device to approximate healthy bladder mucosa across the defect similar to a YV-plasty (57). Ten (53%) patients had VUAS of whom half had some history of radiation (4 with salvage radiation and 1 with salvage prostatectomy). The authors defined surgical success at 4-month follow-up based on the ability to pass a 17-French flexible cystoscope through the prior stenotic segment. Outcomes were reported in combination with BNC patients. Median operative time was 55 minutes and catheter dwell time was 1 week postoperatively. At median follow-up of 6 months, 17 (89%) patients were surgically successful. Both patients who were unsuccessful ultimately met criteria after a second attempt at endoscopic re-alignment. No differences were observed between International Prostate Symptom Score (IPSS) scores before and after intervention. Lastly, no de novo urinary incontinence was observed (56).

Surgical treatments

For patients who fail endoscopic VUAS management, reconstruction may be offered. Reconstructive surgical approaches include open perineal, open abdominal, and robotic-assisted surgical techniques. We provide a review of the literature regarding these techniques.

Open VUAS reconstruction: perineal, abdominal, and abdominoperineal

Multiple studies have examined outcomes for VUAS reconstruction by perineal approach (58-60). In 2014, Reiss et al. evaluated the safety and efficacy of managing recurrent VUAS with open transperineal re-anastomosis in 15 patients. Reconstructive technique involved wide mobilization of urethra, ensuring tension free anastomosis. Surgical success was defined as the absence of recurrence during follow-up. The mean length of VUAS was 3.1 cm. At a mean follow-up of 20.5 months, 14 (93.3%) patients were surgically successful. Pre-operative incontinence was present in 14 patients; however, incontinence was exacerbated in 9 (60%) patients postoperatively. An AUS was implanted in 67% of patients. For quality of life, 13 (87%) patients reported improvement postoperatively (58).

In 2019, Shahrour et al. outlined their surgical technique and presented their experience with recurrent VUAS managed by transperineal approach using a dorsal buccal mucosa graft (BMG) in 4 patients. Preoperative characteristics were notable for 3 (75%) patients having had prior radiation, 7 unsuccessful endoscopic interventions on average, all patients being incontinent, and a mean stricture length of 2.5 cm. The mean operative time was 177 minutes, and patients were discharged on postoperative day 2. At 3 months, the surgical success rate was 100% with a mean maximum urinary flow of 20 mL/s (59).

In 2024, Sterling et al. reported a multi-institutional experience of 45 patients with post-radiation VUAS reconstructed using dorsal BMG onlay via transperineal approach. Population characteristics were notable for 5 (11%) patients with previous salvage prostatectomy, median stenosis length was 2.3 cm, and stenosis location was anastomotic in 21 (47%) patients versus bulbomembranous in 24 (53%) patients. Recurrent VUAS was defined as requiring any additional intervention. At median follow-up of 21 months, 7 (16%) patients experienced VUAS recurrence. For urinary incontinence, 28 (62%) patients were incontinent preoperatively and postoperatively; however, no cases of de novo incontinence were reported. AUS implantation occurred in 17 (63%) patients who had postoperative incontinence (60).

In 2014, Nikolavsky et al. presented 12 patients with recurrent VUAS managed by either abdominal, perineal, or abdominoperineal approaches. Population characteristics included 25% having prior radiation, 43% with complete obliteration, and median stenosis length of 2.5 cm. The abdominal approach typically involved inferior partial pubectomy to maximize exposure. The VUAS was then excised and re-anastomosis was performed with interrupted sutures. The perineal approach was reserved for short stenosis and an intact bladder neck. The urethra was dissected and mobilized separating the corpora cavernosa and performing a partial inferior pubectomy. A gracilis flap was considered in irradiated cases. For longer stenotic segments >3 cm involving the bladder neck, the authors proceeded with the hybridized abdominoperineal approach incorporating both abdominal and perineal techniques. For re-anastomosis, interrupted bladder neck sutures were placed abdominally and transferred through the surgical defect to the perineum for anastomosis completion. Outcomes included length of stay, repair patency, complications, urinary continence. Median operative time was 347 minutes and length of stay was 3 days. All bladder necks were tapered at time of surgery and 8 (67%) patients required pubectomy. At a median follow-up of 75.5 months, 11 (92%) of patients maintained patent reconstructions and 3 (25%) patients were continent (11).

Robotic reconstruction of VUAS

As robotic-assisted surgery has become widespread in urologic practice, the robotic modality has also grown in the discipline of reconstructive urology (61-63). Given the relative novelty of robotic reconstruction of VUAS, the literature regarding this topic is limited to a handful of small case series. Granieri et al. presented the earliest report of a robotic technique for the management of recalcitrant BNC in 2018. The study featured 7 patients, of whom 1 patient had VUAS. The technique involved a transabdominal robotic approach which mobilized the bladder via the space of Retzius and identified the stenotic segment with a combination of NIRF and white-light cystoscopy. Once identified, the stenotic segment is incised with an inverted Y and a V-shaped bladder flap is mobilized distally to be approximated to the previously incised tissue, thereby augmenting the caliber of the lumen. Numerous studies since then have described treatment of non-obliterated VUAS with the YV-plasty approach. Longitudinal postoperative outcomes have recently become available to assess the efficacy and durability of the YV-plasty (62-65).

In 2022, the TURNS group reported outcomes of refractory VUAS managed with either multi- or single-port robotic reconstruction via a transabdominal approach utilizing either excision with primary anastomosis (re-anastomosis) or an anterior bladder flap technique, such as YV-plasty (63). Primary outcomes were surgical site patency (allowing for passage of a 17-French cystoscope) or peak urinary flow >15 mL/s. In this study, 32 patients met inclusion criteria, among whom 15 (47%) patients were found to have obliterative VUAS intraoperatively and 16 (50%) patients had prior pelvic radiation. Re-anastomosis was performed in 15 (47%) patients while anterior bladder flap occurred in 17 (53%) patients. At median follow-up of 12 months, 24 (75%) patients had surgical site patency. Among the 8 (25%) patency failures, 2 were re-anastomoses and 6 were anterior bladder flaps. Patency failure most likely occurred within 6 months of reconstruction. There was variation in how patency failures were managed: revision robotic reconstruction (2 patients), endoscopic revision in (4 patients), and catheterization in (2 patients). Median length of stay was 1 day and median catheter dwell time was 20 days. Among the cohort, complications occurred at 30 days in 5 (16%) patients: 3 catheter obstructions, 1 deep vein thrombosis + small bowel obstruction, and 1 redo repair of rectourethral fistula which was repaired during the initial procedure. Beyond 30 days, complications occurred in 2 (6%) patients: vesicopubic fistula in a YV-plasty patient (treated with robotic rectus flap and fistula closure), pubic osteomyelitis in a re-anastomosis patient (resolved with antibiotics). De novo stress urinary incontinence developed in 2 patients postoperatively. No patients required urinary diversion. While this study features one of the larger cohorts of VUAS reconstructed robotically, there are additional case series with important findings in managing VUAS (63,65).

Bearrick et al. also presented results in 2022 on robotic posterior urethral reconstruction in 21 patients who failed prior endoscopic management. Among the cohort, 15 patients had VUAS: 10 patients without radiation and 5 patients with prior radiation. The authors reported distinctly separate outcomes for VUAS patients with and without prior radiation. Functional success was defined as post-void residual <50 mL and anatomic success was defined as passage of a 17-French flexible cystoscope in follow-up. For radical prostatectomy without radiation, VUAS was reconstructed by excision and re-anastomosis, YV-plasty, and downward rotational bladder advancement in 5, 3, and 2 patient(s), respectively. Median operative time and length of stay were 5.44 hours and 1 day, respectively. Postoperative anatomic success was reached in 9 (90%) patients, while 1 patient required dilation. Two (20%) patients experienced complications by 30 days: 1 loculated fluid collection with inguinal hernia mesh infection and 1 anastomotic dehiscence with urine leak. At median follow-up of 23.9 months, 100% were functionally successful reporting a median of 0 pads/day. Three (30%) patients had undergone AUS placement. For radical prostatectomy with radiation, VUAS was reconstructed with excision re-anastomosis, urethral pull-through, and YV-plasty in 2, 2, and 1 patient(s), respectively. Median operative time and length of stay were 8.58 hours and 2 days, respectively. Two (40%) patients experienced complications at 30-days: 1 urosymphyseal fistula and 1 partial anastomotic dehiscence. While anatomic success was initially reached in 3 (60%) patients, repeat procedures were required in 4 (80%) patients. Interventions included 1 urosymphyseal fistula repair, 2 ballon dilations, 1 temporary suprapubic tube replacement. At median follow-up of 27.6 months, functional success was reached in 3 (60%) patients; however, for continence, patients reported a median of 10.5 pads/day. Four (80%) patients had undergone AUS placement. The authors’ findings demonstrate safety and durability of robotic reconstruction of VUAS while highlighting the added complexity to reconstructing VUAS in the context of prior radiation (65).

Viegas et al. studied outcomes in 6 patients with VUAS managed with a transabdominal robotic YV-plasty, reporting less favorable peri-operative outcomes. Surgical site patency was evaluated at 1 month postoperatively and at the most recent follow-up visit. Complications occurred in 67% of patients and 50% of patients required long-term reoperation (62).

Instead of performing bladder neck reconstruction transabdominally, Lavollé et al. presented an alternative of extraperitoneal robotic-assisted vesicourethral reconstruction in 2019. They studied reconstructive outcomes in a case series of 6 patients with VUAS, 3 of whom had salvage radiation prior to reconstruction. All patients underwent complete anastomotic reconstruction. No perioperative complications were reported; however, half of the cohort developed recurrences which required endoscopic management and half required future AUS insertion (66).

Liu et al. (64) presented the first experience with robotic BMG posterior urethroplasty in 9 patients, 7 of whom had VUAS that failed endoscopic therapy. Among post-prostatectomy patients, 4 had prior radiation. Mean defect length for the entire cohort was 3.9 cm. Using the single-port robotic platform, either intra-abdominal or extraperitoneal transvesical reconstructions were performed. BMG was used via intra-abdominal posterior urethroplasty inlay and if additional stricture was present more distally, then BMG dorsal onlay was performed. No intraoperative complications occurred, median operative time and length of stay were 377 minutes and 2 days, respectively. Five patients underwent interposition flaps: 3 rectus abdominis, 1 omental, and 1 gracilis. For the entire cohort, at 30 days, postoperative complications included 2 Clavien-Dindo IIIb complications: 1 stricture recurrence requiring balloon dilation and 1 Richter hernia at the rectus abdominis flap harvest site requiring hernia repair without bowel resection. De novo incontinence occurred in 1 patient. Considering case complexity, median follow-up of 11.7 months demonstrated safety and durability of this novel technique for long-segment VUAS with restenosis occurring in 3 of 7 VUAS patients (2 patients with prior radiation developed recurrent stenosis at VUAS site).

For instances of longer segment complex VUAS potentially involving the EUS, a combination approach has been outlined which uses the robot transabdominally to dissect the vesicourethral anastomosis and identify healthy bladder margins followed by open transperineal delivery of the urethra for tension-free anastomosis once the scarred segment has been excised (67,68). Of note, postoperative urinary incontinence is expected after this approach given that the dissection will course through the EUS. Patients may be candidates for AUS placement approximately 3–6 months later (68). This technique is advantageous by circumventing the pubic bone and the need for inferior pubectomy for VUAS involving the EUS, thereby avoiding future pelvic instability (69).

Discussion

Although relatively rare, VUAS is among the most complex conditions that should managed by urologists experienced in genitourinary reconstruction. Global interpretation and comparison of the existing literature pertaining to VUAS management may be challenging for a number of reasons. First, a significant portion of the literature does not specifically differentiate between a true VUAS (occurs after prostatectomy) versus BNC (occurs after bladder outlet procedure) (70). Indeed, many reports group patients with a VUAS and BNC as a single entity. The importance of differentiating between VUAS and BNC is critical given their contrasting etiologies and considerations during management. Understanding these key differences is paramount to interpreting the existing literature and contributing future literature.

Second, even within studies focusing exclusively on VUAS, interpreting and comparing literature is challenging due to the heterogeneity between study population characteristics (i.e., prior RRP versus RARP, radiation status, number/type of previous treatments, hyperbaric oxygen therapy status, and degree of stenosis). For example, treatment considerations for a patient with VUAS with a history of radiation and obliterated lumen would be much different than that for a patient with a VUAS with no history of radiation and a mild narrowing. Establishment of a standardized staging criteria for VUAS that may account for variations in clinical characteristics may allow urologists to gain further insight into diagnosis and treatment for VUAS, and also facilitate comparison of studies.

Third, there is currently no standardized definition of success after treatment of VUAS. For instance, review of the literature revealed surgical success criteria defined as improving maximum urinary flow, reducing post-void residual, not requiring future procedures, or the ability to pass the flexible cystoscope. Establishment of a standardized definition of success after treatment of VUAS is critical to guide clinical practice and allow for comparisons of studies within the literature.

Less invasive endoscopic therapies appear to have lower success rates, higher recurrence rates, and a notable risk of de novo urinary incontinence compared to surgical reconstruction, especially in cases of prior pelvic radiation. However, given the potential success with these approaches and the potential to avoid a major surgical reconstruction, it is reasonable for clinicians to attempt endoscopic therapy prior to considering definitive reconstruction. Furthermore, endoscopic management may be a more appealing option for patients with life expectancy shorter than 10 years or significant comorbidities that could complicate an anastomotic reconstruction. Currently, there are a multitude of endoscopic treatment options for VUAS available ranging from simple dilation, dilation with a paclitaxel drug-coated balloon, incision and/or resection, and intralesional injection with MMC and/or steroids. However, as there are no comparative studies demonstrating superiority of one specific endoscopic option over another, the specific endoscopic option selected should be at the discretion of the surgeon. Future studies reporting long-term outcomes with these treatment modalities and comparing outcomes between endoscopic treatment options are necessary to help guide treatment decisions.

When a VUAS is recalcitrant to endoscopic management, reconstructive surgery should be considered. Traditionally, VUAS reconstruction was approached in an open manner via a perineal only, abdominal only, or perineal and abdominal approach. However, this operation is technically challenging given the difficult location of the target anatomy, all patients have previously undergone radical prostatectomy, and a significant portion of patients have previously undergone pelvic radiation. Additionally, there is a relatively high risk of de novo or worsening urinary incontinence (11,58,60). We strongly believe that the robotic modality is well-suited for VUAS reconstruction as it may address some of the limitations with open surgery. First, the robot modality is well suited for visualization and dissection in the deep pelvis due to the magnified three-dimensional vision and ability to angle the camera (Figure 1). Second, dissection in challenging re-operative and radiated planes can be aided by NIRF. The precise location of the VUAS may be identified by inserting a white-light cystoscope to the level of the VUAS and then turning on the NIRF. This allows for precise localization of the VUAS (Figure 2). Additionally, after injecting intravenous indocyanine green, NIRF allows for assessment of tissue perfusion. This can be particularly helpful when mobilizing flaps during a YV-plasty (Figure 3). Third, the robotic modality may minimize the risk of postoperative de novo and worsening incontinence. The relatively lower rates of de novo urinary incontinence and AUS implantation associated with robotic VUAS management (63,65) relative to open approaches is likely attributable to the approach which may be performed entirely above the level of the EUS and the heightened sense of spatial awareness regarding the location of the EUS due to improved visualization techniques. As we await longer-term outcomes for robotic reconstructive approaches, the success rates in early follow-up at high-volume centers provide reassuring results on durability and minimizing de novo urinary incontinence (63-65).

Figure 1.

The robotic modality with the 30-degree camera allows for enhanced visualization of the VUAS under the pubic symphysis. VUAS, vesicourethral anastomotic stenosis.

Figure 2.

Identification of the distal VUAS margin before (A) and after (B) placing a white-light cystoscope to the level of the VUAS and visualizing under near-infrared fluorescence. VUAS, vesicourethral anastomotic stenosis.

Figure 3.

Assessment of tissue perfusion of V-shaped flap of bladder before (A) and after (B) intravenous indocyanine green and visualization under near-infrared fluorescence.

At our high-volume robotic reconstructive center, patients with VUAS are typically considered for reconstructive surgery after having failed at least one endoscopic treatment approach. All patients with a history of radiation are referred for hyperbaric oxygen therapy to promote neovascularization and optimize wound healing (71). Typically, patients will preoperatively undergo 40 dives at 2.5 atmospheres absolute (ATA). We utilize a treatment decision-making framework for VUAS that depends on findings at the time of pre-operative endoscopic evaluation that assesses for VUAS caliber and location relative to the EUS (Figure 4). For stenoses ≥10 French without EUS involvement, we recommend patients undergo a non-transecting bladder flap (either YV-plasty or T-plasty) (61,63,72). For stenoses <10 French without EUS involvement, we recommend excision and primary anastomosis. When an excision and primary anastomosis is not able to reach the defect due to severe fibrosis, poor bladder mobility and/or long VUAS length, we perform an option kindred to the previously described Tanagho flap (73) that involves abandoning the urethrovesical junction and pursuing bladder neck closure, downward rotational bladder advancement, and creation of a tubularized bladder flap functioning as a new bladder neck for subsequent anastomosis to the urethra. Lastly, for any French stenoses involving and extending beyond the EUS, a combination robotic transabdominal and open transperineal approach is pursued. We use a white-light cystoscope and subsequently visualize the light under NIRF to assist with intraoperative localization of the VUAS. Intravenous indocyanine green is utilized intra-operatively as a real-time contrast agent to assess tissue perfusion. Omental interposition flaps are routinely used for interposition between the reconstruction and pubic bone, and if not feasible then a rectus flap will be used. Additionally, gracilis muscle flaps are a consideration for the combined robotic and transperineal approach. We are currently working on a multi-institutional study investigating intraoperative decision-making and intermediate-term postoperative outcomes after robotic VUAS reconstruction. As more data pertaining to treatment-associated outcomes for VUAS emerges, future systematic reviews or meta-analyses would be valuable additions to the literature.

Figure 4.

Robotic VUAS reconstruction algorithm that is dependent on VUAS caliber and EUS involvement. *, If unable to perform due to fibrosis and/or length of VUAS. EUS, external urinary sphincter; Fr, French; VUAS, vesicourethral anastomotic stenosis.

Conclusions

VUAS is distinct in pathogenesis and management from BNC. The staging of VUAS and criteria for successful VUAS management varies widely in the extant literature, suggesting a need for consensus definitions. Several endoscopic approaches are available, which can be a reasonable option for initial treatment. However, in cases of recalcitrant VUAS, definitive reconstruction should be offered. Robotic technology grants excellent visualization with advanced imaging techniques and precision to facilitate durable reconstruction while minimizing risk of damage to the EUS.

Supplementary

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Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All clinical procedures described in this study were performed in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Helsinki Declaration and its subsequent amendments. Written informed consent was obtained from the patient for the publication of this article and accompanying images.