Expanding Horizons: Robotic Surgery in Functional and Reconstructive Urology

Background

Bladder neck contracture (BNC) is a common complication after BPH surgery and results from fibrosis and narrowing of the bladder neck [4]. This condition can cause bladder outlet obstruction (BOO) and substantially impair quality of life [5, 6]. Reported incidence rates of BNC after transurethral resection of the prostate (TURP), holmium laser enucleation of the prostate (HoLEP), and thulium laser enucleation of the prostate are 0.3%–9.2%, 2%, and 2.2%, respectively [7, 8]. Based on these rates, it is estimated that nearly 2,500 new cases of BNC occur annually in the United States.

BNC is often straightforward to manage and typically does not involve the external urethral sphincter (EUS), thereby posing minimal risk of incontinence. In addition, it is described as unrelated to radiation therapy and may respond well to advanced treatment modalities when initial dilation or incision fails, with reported success rates of 90%–100% [9].

Surgical Technique

In the restoration of BNC initially described by Young in 1953, robot-assisted Y–V plasty has become one of the most well-known and established treatment modalities [10]. Typically, Y–V plasty is performed for strictures measuring 10F or larger, whereas complete excision and anastomosis are reserved for strictures measuring less than 10F, with modifications based on patient anatomy and surgical history [11].

Using a transperitoneal approach, the procedure begins with dissection of the space of Retzius and proceeds to the level of the BNC. A 0° lens is commonly used for visualization. To precisely localize the stricture, retrograde flexible cystoscopy is performed with Firefly mode enabled, with visualization facilitated using the TilePro system (Fig. 1A). Under cystoscopic guidance, the stricture is incised longitudinally using robotic monopolar scissors until adequate patency is achieved. Dense fibrotic tissue is then excised circumferentially, followed by bladder neck reconstruction using double-armed barbed sutures to maintain repair integrity (Fig. 1B).

Fig. 1.

Bladder neck reconstruction (Y–V plasty). (A) The stricture site is identified using a flexible scope and Firefly mode before the longitudinal incision is made. (B) Fibrotic tissue at the bladder neck is excised, and bladder neck reconstruction is performed. (C) When creating the bladder flap, care is taken to ensure that it is sufficiently wide to avoid narrowing; a flap that is too narrow (X) should be avoided, whereas an adequately wide flap (O) is recommended. (D) The Y–V plasty is completed with a double-armed suture, followed by a filling test to confirm repair integrity.

To create the bladder flap, a reversed “Y” is marked on the anterior bladder wall using monopolar electrocautery. The tip of the V-shaped flap is advanced and anastomosed to the distal end of the stricture incision, and the bladder neck is widened using barbed sutures. A 22F Foley catheter is inserted to maintain urethral patency. A common technical error is creating an overly narrow flap (Fig. 1C). To avoid this, the “Y” should be designed with a sufficiently wide base. After flap creation, intravenous ICG is administered to identify and excise poorly vascularized areas. After completion of the Y–V anastomosis (Fig. 1D), a filling test is performed to confirm repair integrity. Finally, the upper peritoneum is sutured to close the space of Retzius.

Considerations

Several studies of BNC reconstruction report an average prostate volume of approximately 30 mL [12, 13]. This finding suggests that smaller prostates may be more susceptible to BNC. It also underscores the need for caution when considering BPH surgery in patients with smaller prostates and highlights the importance of avoiding excessive bladder neck resection [13]. In addition, potential complications of Y–V plasty, including persistent voiding dysfunction, should be considered carefully in patients with detrusor underactivity (DU) [14].

Background

Radical prostatectomy (RP) is one of the most commonly performed robotic procedures in urology. Although functional outcomes are generally favorable for most patients [15, 16], vesicourethral anastomotic stricture (VUAS) can occur as a result of scar formation and may substantially affect quality of life.

Recent reports indicate that the prevalence of symptomatic VUAS is approximately 1.3%–2.4% after robot-assisted RP, compared with 7.1%–19.8% after open RP [17-20]. However, prevalence increases 1–3 years after radiation therapy, with an estimated incidence of 2.7%–10% in patients undergoing both RP and external beam radiation therapy [21].

Etiology

The causes of VUAS can be grouped into 2 broad categories. First are technical factors during RP, including inadequate mucosa-to-mucosa anastomosis, insufficient tension control, extravasation, or the influence of foreign bodies such as staples or clips [22]. Second are radiation-related effects before or after RP. Obliterative endarteritis and apoptosis of tissue progenitor cells are described as key mechanisms, and free radicals and reactive oxygen species are implicated in progressive fibrosis [23].

Surgical Technique (Why VUAS Is Challenging)

Scar formation in VUAS is associated with the postoperative inflammatory phase and can lead to dense fibrotic narrowing at the vesicourethral anastomosis [24]. Management strategies often begin with chronic catheter-based approaches such as clean intermittent catheterization (CIC), a suprapubic tube, or an indwelling Foley catheter. Endoscopic treatments—including balloon dilation and direct vision internal urethrotomy with or without injection—are commonly pursued next, with abdominal and/or perineal reconstruction reserved as a final option. One study reported that only 58% of patients responded to a single endoscopic treatment [25]. The natural history of untreated refractory VUAS can involve lifelong repeated catheterizations and multiple endoscopic procedures and may progress to urinary diversion [26].

Refractory VUAS after RP presents challenges distinct from BNC. It can be technically demanding because of its proximity to the sphincter mechanism and is also challenging in terms of access, visualization, and assessment of tissue viability. Open reconstruction carries risks of injury to the rectum, urethral sphincter, and cavernous nerves. In addition, reanastomosis via a perineal approach can be particularly difficult and may require abdominoperineal dissection or pubectomy [27]. Excision and primary anastomosis (EPA) is reported to achieve success rates of 60%–87% [28, 29]. However, even when patency is achieved after open reconstruction, de novo stress urinary incontinence (SUI) is reported to be nearly universal (93%–100%) [30, 31]. Patients with prior perineal incisions—particularly those with a history of pelvic radiation therapy—also have an increased risk of erosion with artificial urinary sphincter (AUS) cuffs.

Robotic reconstruction of VUAS provides the advantage of antegrade access to the genitourinary diaphragm. An abdominal approach may reduce incontinence risk and can facilitate localization of VUAS using white-light cystoscopy and NIRF. Combining intravenous ICG with NIRF can also be useful for evaluating tissue perfusion.

Robotic VUAS Reconstruction Algorithm (Fig. 2)

Fig. 2.

VUAS reconstruction treatment flow. The treatment approach for VUAS reconstruction is determined by the size of the residual lumen and the involvement of the external urethral sphincter (EUS) following endoscopic evaluation. EPA, excision and primary anastomosis.

Endoscopic evaluation, including assessment of stricture caliber and its relationship to the EUS, is central to decision-making. During cystoscopy, the stricture caliber and its relationship to the EUS should be determined, and radionecrosis should be assessed. If radionecrosis is evident, reconstruction is generally not recommended. Magnetic resonance imaging is also recommended to assess proximity to the pubic bone and evaluate for osteomyelitis. When the proximal extent of the stricture is unclear, a retrograde urethrogram can be useful for determining VUAS length.

In the subsequent algorithm, EUS involvement is a key determinant. If the EUS is not involved and the residual lumen measures 10F or larger, a nontransecting bladder flap (Y–V plasty) may be an appropriate option. If the lumen caliber is less than 10F, EPA is often preferred. When EPA is challenging, an anterior bladder flap technique with minimal radiation influence, such as the Tanagho flap [32], may be considered as an alternative.

If the stricture extends past the EUS, regardless of lumen caliber, perineal dissection followed by a urethral pull-through procedure can be performed to achieve a tension-free anastomosis [33].

Background

Depending on the stricture location, a wide range of reconstructive options are available (Fig. 3). Because the ureter connects the kidney to the bladder, upper urinary tract reconstruction requires substantial instrument mobility, making laparoscopic and robotic approaches well suited to these procedures. Because the surgical plan may change intraoperatively based on the location and extent of the ureteral stricture—and because suturing constitutes a substantial component of many reconstructions—robotic approaches may be preferable [34].

Fig. 3.

Robotic reconstructive options for ureteral obstruction. Robot-assisted ureteral reconstruction offers a wide range of options due to the ability to access the upper and lower ureter as well as the bladder. BMG, buccal mucosa graft; U-U, ureteroureterostomy.

Simple Ureteral Reimplantation

The choice between a transvesical and an extravesical approach, as well as the decision to use a refluxing or nonrefluxing technique, often depends on the surgeon’s preference. Advantages of this technique include easier length management than end-to-end ureteroureterostomy and high success rates attributable to the robust bladder blood supply. However, this approach is generally limited to short-segment strictures, and approach-specific risks should be considered [35].

Psoas Hitch

When the defect length extends beyond a few centimeters, simple ureteral reimplantation may become infeasible, making a psoas hitch a more practical option. One advantage of this technique is that extensive dissection of the stricture segment is not required. In addition, bladder hitching can reduce tension at the anastomosis during storage and voiding cycles. The procedure involves suturing the bladder dome to the psoas minor tendon or the psoas major muscle. In female patients, the psoas minor tendon can be difficult to identify, and inadvertent incorporation of the genitofemoral nerve is a concern. In such cases, it may be safer to suture the psoas major muscle, using absorbable sutures placed vertically and not too deeply. This technique can cover up to 8 cm from the ureterovesical junction (UVJ). However, it is not suitable for patients with a contracted bladder or bilateral strictures [36].

Boari Flap

For longer defects, a Boari flap is commonly used and can typically provide sufficient length up to the L5 level [37]. It is generally performed in conjunction with a psoas hitch, using a rectangular flap approximately 3–4 cm wide. A sufficiently wide pedicle is essential to support neoureteral patency and maintain adequate vascular supply. A Boari flap can cover up to 12 cm from the UVJ; however, it is not suitable for patients with a contracted bladder. High success rates for robot-assisted Boari flap procedures have been reported in multiple studies [38, 39]. In patients with adequate bladder capacity, a flap up to 10–15 cm long can be created with careful construction. To reduce ischemia risk, the base of the flap is recommended to be at least 5 cm wide. After the initial anastomosis between the ureter and bladder flap is completed, alignment is confirmed, and ICG is injected to verify adequate perfusion of both the ureter and flap [40].

Ureteroplasty Using Buccal Mucosa Graft

Two main approaches are used for buccal mucosa graft (BMG) ureteroplasty: patch grafting and tubularized reconstruction. However, patch grafting after ureterotomy is most commonly performed [41]. For strictures with preserved luminal patency, an onlay technique is used, in which a longitudinal incision is made along the stricture and the graft is sutured over the resulting ureteral defect. In contrast, for obliterative strictures or cases in which the ureteral mucosa is nonviable, an augmented anastomotic technique is used. This involves resecting the diseased segment, performing anterior spatulation at both ends, anastomosing a posterior ureteral plate, and suturing the graft over the resulting defect [42].

A notable feature is the need for omental wrapping to support graft vascularity. Multiple approaches to omental placement have been described; however, provided that adequate graft contact is maintained, several methods are acceptable. Use of BMG for urinary tract stricture repair, including ureteral and urethral strictures, has increased. A key advantage is preservation of the ureteral plate, which supports vascular supply [34]. A limitation is the inability to bypass the diseased ureteral segment, which necessitates meticulous dissection of the affected area. BMG ureteroplasty is generally appropriate for upper- or mid-ureter strictures up to approximately 5 cm. It is also important for the patient to have no conditions affecting the oral mucosa.

Ileal Ureter Replacement

Ileal ureter replacement is often considered a last-resort option for both upper and lower ureteral reconstruction [43]. For upper ureteral reconstruction, it is indicated in long-segment strictures (>6 cm) when BMG is unsuitable, in the presence of multiple strictures, or when contralateral ureteral strictures are present. For lower ureteral reconstruction, additional indications include reduced bladder compliance in the setting of contralateral ureteral strictures [44]. Conversely, this technique is not suitable for patients with active inflammatory bowel disease, a history of extensive bowel surgery, renal insufficiency, or short bowel syndrome. On the right side, the ascending colon can be mobilized to facilitate anastomosis. However, on the left side, mobilization is limited by the sigmoid colon; therefore, a mesenteric window is created to pass part or all of the ileal segment before reconstruction proceeds [45].

Background

Minimally invasive sacrocolpopexy has become increasingly popular compared with vaginal approaches for the treatment of pelvic organ prolapse (POP) [46]. It is commonly considered the gold standard for prolapse repair because it provides higher anatomic success rates than vaginal apical repairs using native tissue [47].

The procedure was first described in 1957 by Arthur and Savage, who performed hysteropexy by suturing the uterine fundus to the anterior longitudinal ligament [48]. In 1962, Lane introduced sacrocolpopexy, describing suspension of the vaginal apex to the anterior longitudinal ligament of the sacrum [49]. Several modifications have since been introduced. The fixation point shifted from the promontory to the S1–2 region, reducing the risk of injury to vascular structures and the hypogastric plexus. Initially, mesh fixation was limited to the vaginal apex; later, mesh arms were extended to the anterior and posterior vaginal walls. Another major evolution has been the widespread use of type I polypropylene macropore mesh, although some surgeons continue to use biologic grafts.

Surgical technique - Is Sacrocolpopexy Effective?

Severe POP is a common and challenging surgical condition. Historically, reconstructive procedures were performed via vaginal approaches; however, advances in minimally invasive techniques have made graft-based sacrocolpopexy an effective option for apical prolapse (Fig. 4). This approach differs from vaginal colpopexy in both the types and rates of complications. Accordingly, risks and benefits should be weighed for each patient, and contemporary evidence should be incorporated to support surgical decision-making.

Fig. 4.

Robot-assisted sacrohysteropexy. Mesh fixation to the sacral promontory is performed after completing posterior and anterior mesh suturing. The procedure is finalized with extraperitonealization.

Mesh-based sacrocolpopexy is highly effective for the treatment of moderate to severe apical POP. Success is often defined using strict criteria: no prolapse below the hymen; Pelvic Organ Prolapse Quantification point C not descending beyond one-third of the total vaginal length; a “No” response to question 3 on the Pelvic Floor Disability Index-20 questionnaire; and no need for repeat prolapse surgery or pessary use postoperatively. Using these criteria, the 5-year success rate is approximately 90%. In contrast, the success rate for native tissue repair under the same criteria is substantially lower, at approximately 30%–40% [50].

However, sacrocolpopexy effectively addresses upper and midvaginal prolapse but may not fully resolve distal vaginal problems, including distal prolapse, bladder neck hypermobility, SUI, distal rectocele, outlet constipation, and perineal body deficiency. Moreover, despite overall symptom improvement and quality-of-life gains after minimally invasive sacrocolpopexy (MIS-SCC), postoperative dissatisfaction is often related to constipation, perceived prolapse recurrence, or issues associated with concomitant SUI procedures [51].

Recent studies report no significant difference in anatomic correction of anterior-apical POP between MIS-SCC and transvaginal anterior mesh surgery. However, MIS-SCC demonstrated better outcomes in correcting posterior vaginal wall defects and preserving overall vaginal length [52]. In addition, among normal-weight, overweight, and obese women, robot-assisted or laparoscopic sacrocolpopexy performed by experienced surgeons appears to have similar intraoperative complication rates. Given the advantages of minimally invasive approaches in obese patients, minimally invasive surgery is recommended as a treatment option for vault prolapse in overweight or obese women [53].

Background

Open simple prostatectomy is performed less frequently because endoscopic approaches for BPH are widely used. Nevertheless, enucleation remains important for large adenomas, and minimally invasive approaches may offer advantages, including reduced blood loss, lower morbidity, and faster recovery. Since Sotelo et al. first reported robotic-assisted simple prostatectomy (RASP) in 2008, the procedure has gained increasing use, particularly from the early 2010s onward, and has been reported as safe and effective [54-56].

Simple prostatectomy may be performed via transperitoneal or extraperitoneal access, either through the bladder (transvesical) or using the Millin technique. The dexterity and degrees of freedom provided by robotic assistance can facilitate enucleation in large glands. One major reason HoLEP is not widely adopted is its steep learning curve, reportedly requiring 25–50 cases. In contrast, RASP can reportedly be learned by surgeons with robotic experience in approximately 10–12 cases [57, 58].

Indications

The primary determinant for selecting simple prostatectomy over other bladder outlet reduction procedures is prostate volume. The American Urological Association guideline on surgical management of BPH recommends considering simple prostatectomy in patients with large prostates. Although the definition of a “large” prostate is subjective, discussion of simple prostatectomy is typically warranted for prostate volumes ≥85 mL [59]. Larger glands are associated with longer TURP resection times, increased complications, and reduced efficiency.

A major advantage of RASP is avoidance of transurethral surgery. In addition, RASP may be considered in patients with prior hypospadias repair, those with a penile prosthesis that makes endoscopic access challenging, or those with orthopedic conditions (e.g., ankylosis of the hip) that complicate lithotomy positioning.

Surgical Technique

Two main approaches are used to expose and remove the adenoma. In the transvesical approach, the bladder is opened to access the adenoma. By identifying the plane between the anterior fibromuscular stroma and the adenoma, the adenoma can be removed while minimizing sphincter injury. Both intra- and extraperitoneal approaches are possible. With the extraperitoneal approach, a Trendelenburg angle of only 10°–15° is often sufficient to limit bowel interference. In the transcapsular approach, an incision is made on the anterior surface of the prostatic capsule. Bleeding may occur from the dorsal vein complex, and if it cannot be controlled with electrocautery, continuous suturing is used for hemostasis. If the median lobe is not prominent, a urethral-sparing technique (Madigan technique) can be performed (Fig. 5). This technique may increase ejaculation preservation compared with conventional methods, with reported rates of 65%–86.6% [60-63].

Fig. 5.

Patent bladder neck observed at 6 months after urethralsparing robotic-assisted simple prostatectomy (RASP). Urethral-sparing RASP may be appropriate when there is no significant median lobe protrusion.

Considerations

Open simple prostatectomy, HoLEP, and RASP share similar surgical principles. Compared with conventional TURP, these approaches allow closer dissection near the sphincter, which can improve efficacy by enabling a larger resection volume. However, endoscopic approaches are associated with a higher risk of transient postoperative SUI [64, 65]. A comparison of perioperative parameters is summarized in Table 1.

Table 1.

Comparison of RASP and HoLEP [64, 65]

The anterior aspect of the prostatic apex (between 10 and 2 o’clock) contains bulky sphincter tissue, which can make the anterior apex challenging to manage during HoLEP. In addition, the apex lacks a true capsule and consists of a long band of fibromuscular stroma tissue [66]. During RASP, the adenoma and fibromuscular stroma are more readily distinguishable. By leaving a portion of fibromuscular stroma intact while resecting the adenoma, sphincter injury may be avoided. This interpretation is consistent with continence outcomes reported in recent studies, in which SUI rates were mostly below 5% [67, 68].

Another important benefit of RASP is avoidance of transurethral surgery, particularly in patients with urethral strictures. Even when only minimal fibrotic bands are observed on cystoscopy, transurethral surgery for large adenomas can exacerbate stricture formation and may not achieve the primary goal of relieving BOO (Fig. 6). Primary endoscopic treatment in such cases has a relatively low success rate of approximately 50% [69]. By avoiding transurethral instrumentation, RASP may offer an advantage in this setting.

Fig. 6.

(A and B) Minimal urethral stricture. In the presence of a urethral stricture, endoscopic treatment carries a substantial risk of aggravation.

Male Robotic AUS

Female AUS

Indication

ISD with urethral hypomobility: Failure of MUS can generally be attributed to 2 categories of factors. The first is patient-related factors, in which the underlying cause of SUI does not align with the mechanism of MUS, which is based on urethral support. The second is surgeon-related factors, such as suboptimal tension adjustment or positioning, which are closely associated with surgical experience and volume. These factors are interrelated. MUS achieves optimal efficacy when positioned at the mid-urethra with appropriate tension adjustment. Studies have shown that success rates decrease when the proximal distance between the tape and the bladder neck during Valsalva is too short. In addition, success rates drop substantially when the tape-to-urethra distance exceeds 5 mm [93, 94]. Wlaźlak et al. [94] reported outcomes for 109 patients with ISD who underwent tension-free vaginal tape with 6 months of follow-up. The overall success rate was 82%, and ISD severity did not significantly impact outcomes. However, reduced urethral mobility was associated with lower success rates, with patients with a hypomobile urethra having a success rate of approximately 67%.

Thus, MUS success in ISD patients decreases substantially when urethral mobility is poor, making tension adjustment more challenging and highlighting why surgeon and patient factors are difficult to separate. This underscores the importance of surgeon experience in repeat procedures. For example, in cases of index MUS failure, high-volume surgeons were reported to reduce failure risk by 25% compared with low-volume surgeons [95]. When ISD is the predominant contributor, even high-volume surgeons may have difficulty improving MUS outcomes. In pure ISD cases, as noted above, repeat MUS success rates fall below 25%. Although comparative data between female AUS and other options are limited, female AUS can be an effective surgical option for severe ISD with urethral hypomobility, alongside fascial slings (Fig. 7).

Fig. 7.

Appropriate indications for female artificial urinary sphincter (AUS). The highlighted area of the chart represents cases where urethral mobility is low and intrinsic sphincter deficiency (ISD) is severe. In such instances, female AUS may serve as an effective surgical option alongside fascial slings. UH, urethral hypermobility.

ISD with urethral hypomobility and DU: A second indication is when DU is also present. AUS is the only anti-incontinence procedure that can support both storage and voiding by increasing outflow resistance at rest when the cuff is closed, while maintaining low outflow resistance during voiding when the cuff is open [92]. The relatively low urinary retention rates reported in AUS series support the hypothesis that AUS generates minimal BOO [96].

During robotic AUS surgery, placing the patient in a deep Trendelenburg position can improve exposure by reducing tissue bulk in the operative field. In addition, because the cuff is positioned at the bladder neck, excessive tightness is typically unnecessary, potentially maximizing its “nonobstructive” profile. Alternative options after failed MUS include fascial slings or Burch colposuspension. In a 2007 randomized controlled trial, fascial slings demonstrated higher success rates for SUI, whereas adverse events—including voiding dysfunction requiring revision and urinary tract infection—were more favorable with the Burch procedure [97]. A study with 2 years of follow-up showed that both procedures increased the BOO index, with a larger increase observed among sling patients (Burch +6.27, Sling +20.12) [96]. These findings suggest that both procedures act by increasing bladder outlet resistance. However, neither these procedures nor bulking agent injections substantially affected MUCP [98, 99]. Therefore, AUS may be a more suitable option for patients with ISD, urethral hypomobility, and DU.

Neurogenic SUI: In women with neurogenic SUI, provided that CIC is feasible, the treatment of choice is a pubovaginal sling (PVS) [100, 101]. More recently, studies have reported the safety and efficacy of synthetic slings, emphasizing their convenience and suggesting that vaginal erosion risk is not substantially higher than the 2%–3% observed in the general population [102]. However, cure rates with synthetic slings are lower than those with PVS, and erosion risk increases with prolonged CIC use [79].

For neurogenic SUI, AUS is reported to achieve higher success rates than PVS [103]. Persistent leakage despite AUS may occur because the bladder neck cuff is positioned within the abdominal pressure zone, which can reduce leakage during increases in abdominal pressure. A distinct advantage of AUS, compared with slings, is its ability to maintain a consistent bladder-pressure threshold for leakage, which may provide protection for renal function.

Pure ISD: A fourth indication is pure ISD. In patients with failed MUS, thorough history-taking is essential. One important example is ectopic ureter, in which abnormal development of the ureterotrigonal connection can result in pure ISD [104]. In such cases, the mesh can be removed, and robotic AUS implantation can be performed. Special attention is required to ensure that the ectopic ureter insertion site is managed appropriately during surgery. When the cuff is placed more distally, outcomes are less favorable, with a reported erosion rate of 22%, failing to leverage the advantages associated with bladder neck cuff placement [105].