Post-Prostatectomy Urinary Incontinence

Abstract

Post-prostatectomy urinary incontinence (PPUI) represents the most bothersome long-term complication of prostatectomy. While the risk of PPUI due to invasive treatments of benign prostatic hyperplasia appears to be low (about 1%), the risk is significantly higher after radical prostatectomy (10–50%). Although both external urethral sphincter deficiency and bladder dysfunctions have been considered responsible for PPUI, sphincter deficiency is the most important determinant. Fortunately, PPUI can be effectively cured by specialized management. The first-line treatment based on pelvic floor muscle training has been shown to accelerate continence recovery. Duloxetine is the only available medical treatment demonstrating clinical efficacy for mild-to-moderate PPUI. However, side effects commonly lead to 15–31% of withdrawal. As a result, in the case of refractory PPUI, more invasive options are recommended including artificial urinary sphincters and male slings. Level 1 evidence has been achieved on the efficacy of these surgical treatments that need to be indicated based on an accurate preoperative workout and shared decision-making.

1. Introduction

Prostate cancer is the most common tumor among men. It has a strong genetic component and is the second most diagnosed tumor worldwide after lung cancer [1, 2]. Radical prostatectomy (RP) and radiation beam therapy represent comparable treatment options for localized disease [3].

One of the major complications of RP is urinary incontinence (UI), with a notoriously negative impact on the patient’s quality of life (QoL) and daily activities [4]. UI is the complaint of any involuntary loss of urine [5], with a prevalence of 11–34% in older men [6, 7]. The occurrence of post-prostatectomy urinary incontinence (PPUI) rate varies from 5 to 40% [8] up to 69% [9], depending on the series of patients examined. These differences in PPUI incidence have been attributed to the surgeon’s experience, surgical technique, length of follow-up, data acquisition methods, and differing continence definitions [10]. Current definitions of continence vary from no leakage at all, no pads use but loss of few drops of urine [11], or the use of no more than 1 pad per day, defined as social continence [12].

The etiology of PPUI is often multifactorial and may depend on the patient’s characteristics, sphincteric competence, anatomic support, pelvic innervation, and technical surgical factors such as extensive dissection, neurovascular bundle damage, and the development of postoperative fibrosis [13]. Several risk factors have been reported, including greater age at surgery, obesity, shorter membranous urethral length (MUL), prostate volume, prior transurethral resection of the prostate (TURP), bladder dysfunction, tumor stage and no nerve-sparing surgery [8, 14].

The most common type of PPUI is stress urinary incontinence (SUI), which consists of involuntary leakage during exertion, sneezing, or coughing [5].

Overactive bladder syndrome (OAB) with urge urinary incontinence can also occur after RP. The underlying mechanisms are still under debate, with an outlined hypothesis of detrusor overactivity due to partial bladder denervation during prostate surgery [13].

Continence status continues to evolve from more than 1 year after RP and about 80% of incontinent patients regain continence status without direct treatment [15]. Conservative strategies for the management of PPUI should be trialed as a first option before proceeding to more invasive options. The most common conservative treatments include behavioral therapy, pelvic floor muscle training (PFMT) with or without biofeedback, electronic stimulation, and pharmacotherapy [16]. When these options fail, surgical management is the treatment of choice with artificial urinary sphincter and male sling implantation.

2. Pathophysiology and anatomic components

The pathophysiology of PPUI has yet to be entirely understood. However, numerous theories have been proposed. Pelvic support and neuromuscular anatomic components have been recognized as significant contributing factors to PPUI [17]. Biological and preoperative factors such as age, high BMI, preexisting lower urinary tract symptoms (LUTS), prostate size, short MUL, and functional bladder alterations have a negative impact on continence status after RP [14].

2.1 Direct damage to the urethral sphincter complex

The urethral sphincter’s complex, which extends from the vesical orifice to the perineal membrane, comprises an internal sphincter (lissosphincter) made of smooth muscle and an external sphincter (rhabdosphincter) made of skeletal muscle [18]. During everyday activities, when there is minimal strain on the bladder outflow, the internal sphincter is responsible for maintaining continence (passive continence). It sustains tone for an extended time with little effort [14, 18]. On the other hand, the external sphincter is responsible for continence under stress (active continence). It comprises slow and fast twitch fibers that allow a tonic contraction for baseline continence and temporary recruitment in response to rapid pressure rise and/or voluntary blockage of the urine flow [18, 19].

Preservation of the internal sphincter is believed to be achievable through bladder neck-sparing surgery. The preservation of the internal sphincter complex has been observed to lead to a quicker return to continence and a reduced incidence of postoperative incontinence [20, 21]. However, Marien and Lepor [22] showed that sparing the bladder neck does not significantly impact continence rates. Furthermore, bladder neck preservation may increase the risk of positive surgical margins in case of a tumor located at the prostatic base.

External urethral sphincter deficiency is considered the most important determinant of PPUI [23]. Transurethral ultrasound examination has revealed thinning or atrophy, and compromised contractility [24]. Sphincteric incontinence is the urodynamic measurement’s most common finding [25].

The contribution of neurovascular bundles (NVBs) in the innervation of the external urethral rhabdosphincter is a topic of ongoing debate. At the same time, the effect of NVB preservation during RP on erectile function is evident [26]. Some authors believe that NVB damage affects the continence mechanism and that preservation leads to at least an earlier continence recovery after surgery [20, 27, 28, 29]. However, other authors found no difference in continence rates between nerve-sparing and nonnerve-sparing techniques [22]. Recent results from a randomized clinical trial (IMPROVE trial, NCT02367404) [30] of 240 men with organ-confined prostate cancer who underwent RP, demonstrated that NVB preservation was the only factor associated with continence recovery.

2.2 Damage to the supporting structures of the membranous urethra

The male urethra’s supporting structures can be divided into the anterior and posterior supporting structures and the pelvic floor (levator ani muscle). The pubovesical, puboprostatic ligaments and the tendinous arch of the pelvic fascia form the anterior urethral support structures. The ligaments stabilize the location of the bladder neck and the membranous urethra to the pubic bone [31]. The posterior support comprises the central perineal tendon, the Denonvilliers’ fascia, and the rectour-ethralis muscle [32]. The third support structure includes the levator ani muscle and surrounding fascia [33]. The pelvic floor is not directly connected to the urethra, but it contributes to continence by exerting an occlusive force on the urethra via increased intra-abdominal pressure [33, 34].

PPUI can be improved by maintaining the integrity of the puboprostatic and pubovesical ligaments, allowing proper sphincter functioning [35, 36]. Several studies have demonstrated that the reconstruction of the posterior musculofascial plate of Denonvilliers (also known as the Rocco stitch) appears to improve PPUI [36, 37, 38]. However, some surgeons did not observe a similar improvement in continence after RP [22]. Total pelvic reconstruction with anterior and posterior fixation and anchoring of the bladder urethra anastomosis and the sphincteric complex appear to improve biomechanics and continence [36]. Like the Rocco stitch, this technique prevents urethral stump recession [37] and reduces anastomosis tension, improving mucosal coaptation. However, definitive evidence of their efficacy in the prevention of long-term PPUI still needs to be identified.

Due to the anatomical complexities of the structures surrounding the prostate gland, the surgeon’s experience level is one of the most significant determinants of successful outcomes. The primary intraoperative and postoperative mechanisms of injuries are summarized in Table 1 [24].

Intraoperative injuries			Postoperative injuries
Muscle injuries	Nerves injuries	Supporting structures injuries
Direct damage during apical dissection	Neurovascular bundles resection	Cutting of puboprostatic ligaments	Urethral fibrosis due to devascularization and/or radiotherapy
Electrocautery	Hypogastric plexus damage during lymphadenectomy	Cutting of posterior urethral attachments (Denonvillier’s fascia)	Disordered reinnervation
Hemostatic and anastomotic sutures	Electrocautery and tractions, bladder mobilization	Disruption of endopelvic fascia	Bladder neck strictures and incision
Devascularization	Anastomotic sutures at 5–7 o’clock	Detachment from perineal body	Hemostatic clips erosion and extrusion

Table 1.

Intraoperative and postoperative injuries directly or indirectly affecting external urethral sphincter function.

2.3 Detrusor dysfunctions

Detrusor dysfunctions have been attributed to postoperative bladder decentralization, inflammation and/or infection, and geometric bladder wall alteration linked to preexisting hypoxemia with/without neuroplasticity [39]. Detrusor dysfunction was infrequently a single diagnosis and was typically accompanied by intrinsic sphincteric dysfunction. Surgical damage to the pudendal nerve fibers that innervate the rhabdosphincter has functional consequences. In 2–77% of patients, detrusor overactivity was a de novo dysfunction. Patients with impaired bladder compliance ranged from 8 to 39%, with approximately 50% of cases being de novo. Detrusor hypocontractility was observed in 29–61% of patients, was de novo in 47%, and recovered in about 50% of patients [39].

Detrusor contractility may be impaired during surgery. Postoperative detrusor underactivity following RP seems to be an irreversible phenomenon persisting even over the long term [40].

3. Diagnostic evaluation

A comprehensive assessment typically begins with a detailed medical history, physical examination, and an objective assessment of symptoms.

The medical history should focus on the type, timing, and severity of incontinence throughout the day, the presence or absence of nighttime and gravitational incontinence, and the presence of incontinence-triggering situations (e.g., straining, coughing, or sneezing). The history should also assess any preexisting LUTS, details regarding the prostatectomy procedure, comorbidities, prior radiotherapy, interventions for urethral strictures or incontinence, and the oncological status [41].

The physical evaluation should include an abdominal, neuro-urological, and perineal examination, as well as a digital rectal examination. Furthermore, manual dexterity should be assessed before an artificial urinary sphincter (AUS) implantation, which requires manipulation of the activating pump [42].

Micturition time charts and bladder diaries are standardized tools for measuring and monitoring symptom severity, evaluating the frequency, number of incontinence episodes, voided volumes, and 24-h urinary output [43]. Available validated questionnaires include the International Consultation on Incontinence-Short Form [44] and the UCLA/RAND-Prostate Cancer Index Urinary Function Score [45], which are the most frequently used. Patients’ subjective perception of how much they leak is unreliable; therefore, objective measures should be required for evaluation [46]. Pad count appears to be a poor measure of the degree of UI due to limitations such as different sizes, pad absorbency, and degree of saturation [47, 48]. On the other hand, pad weight is recognized as the most accurate metric for UI assessment [47]. Evidence indicates that the 24-h and 48-h pad weighing tests are the most accurate for quantifying and diagnosing UI severity [47, 49].

The primary diagnostic should be performed before scheduling initial conservative treatment, including urinalysis to rule out infection and bladder ultrasound to assess postvoid residual urine volume [41].

If this attempt fails and surgical treatment is planned, a more invasive diagnosis should be performed [41]. Urethrocystoscopy aims to rule out urethral pathologies, such as bladder neck stenosis or urethral stricture, that may complicate a future surgical approach. Urethroscopy can also be used to perform the repositioning test, which consists of applying gentle mid-perineal pressure parallel to the anal canal while a 0° cystoscope is positioned distally of the sphincter region, and a view of the entire circumference of the external urinary sphincter is obtained. The test yields a positive result when the sphincter autonomously and reflexively closes concentrically, exhibiting complete closure during the repositioning of the posterior urethra [50]. This evaluation is essential in determining the patient’s residual sphincter function and determines suitability for potential retrourethral sling implantation [50].

A urodynamic test is required if the patient has neurogenic disorders or OAB symptoms, especially to assess detrusor function [51]. However, the use of urodynamics in therapeutic decision-making is still debated. As reported by some authors, a higher preoperative Valsalva Leak Point Pressure (VLPP) (>70 cm H₂O or > 100 cm H₂O) better predicts successful outcomes for male sling implantation [52, 53]. In contrast, Han et al. found no negative impact of an impaired preoperative VLPP on functional outcomes after male sling placement [54]. In patients undergoing artificial urinary sphincter implantation due to intrinsic sphincter deficiency, there was no correlation between preoperative urodynamic findings and surgical outcomes [55]. Recent evidence indicates that the urodynamic study might not be relevant in all PPUI patients [56].

Urethrocystography may be a valuable supplementary diagnostic tool in cases suspicious of urethra abnormalities to rule out or better characterize a urethral stricture or bladder neck contracture [57].

4. Treatment options

4.1 Conservative and pharmacological treatments

After RP, improvements in continence status will evolve from the early postoperative period until the end of the first year [8, 58]. Before proceeding to more invasive treatments, conservative management should be evaluated, and patients should be monitored regularly to determine the degree of improvement [16]. The most common conservative treatments are lifestyle interventions, physiotherapy (PFMT) with or without biofeedback or electrical stimulation, and pharmacotherapy.

Lifestyle interventions include time voiding or double voiding, fluid restriction, smoking cessation, and reducing bladder irritants (caffeine, alcohol, hot spices) [16, 41].

PFMT consists of a program of repeated voluntary pelvic floor muscle contractions to improve the closure mechanism due to the levator ani muscle [59, 60]. According to the current European Association of Urology (EAU) guidelines, PFMT should be offered to all patients undergoing RP to speed up postoperative continence recovery [41]. Debate on combining PFMT with additional biofeedback training or electrical stimulation is ongoing. Current evidence supporting PFMT with or without biofeedback is conflicting; some randomized trials demonstrated improved continence thanks to biofeedback therapy [61], and others indicated no benefit [62]. Based on 7th International Consultation on Incontinence (ICI), to achieve a significant improvement, PFMT should be performed for at least 3 months from RP and should be offered for periods of up to 6–12 months [63]. Evidence suggests that electrical stimulation may accelerate urinary continence recovery, but no long-term benefit has been demonstrated at 6 months or more after surgery [64].

Regarding pharmacologic treatments, no approved drugs yet exist. Antimuscarinics, phosphodiesterase inhibitors, and alpha-adrenergic agonists have been proposed as potential therapies for PPUI, especially in patients with OAB symptoms, demonstrating unexciting results [65].

Duloxetine, a serotonin-noradrenaline reuptake inhibitor, is the only available medical treatment that showed clinical efficacy for mild-to-moderate PPUI, increasing the neural tone of the urethral sphincter to prevent incontinent episodes [66, 67]. It has been approved for female stress urinary incontinence in some countries, but there is evidence that it reduces SUI-related symptoms in males [68, 69]. Gastrointestinal and central nervous side effects are common, leading to 15–31% of withdrawal [70]. These side effects are usually limited to the initial phase, and the use of duloxetine can be efficacious with persistence [71]. Some authors showed that duloxetine has synergistic effects when combined with PFMT [72]. However, clinical evidence supporting their routine use is weak. These two treatments seem to improve early continence recovery moderately, but neither significantly improves long-term urinary continence [73]. Recent results from a randomized clinical trial by Sanchez-Salas et al. demonstrated that PFMT and duloxetine do not improve urinary continence recovery, may have a negative impact on quality of life, and should not be routinely recommended to patients after RP [30].

In the case of refractory PPUI, more invasive and effective options are recommended.

4.2 Surgical treatments

If conservative therapy fails, surgical treatment options should be offered. Invasive treatment options include peri-urethral balloons, bulking agents, artificial urinary sphincters (AUS), and male slings.

AUS and perineal slings are the most used surgical treatment options. European guidelines recommend the AUS implantation for patients with moderate-to-severe PPUI after unsuccessful conservative treatment. Conversely, for mild-to-moderate PPUI, fixed perineal slings are recommended [74]. As a result, moderate urinary incontinence is in a “grey area” in which both AUS and slings are indicated, despite growing evidence that AUS significantly outperforms fixed slings in men with moderate PPUI [75].

Peri-urethral balloons can be considered a salvage therapy for mild, persistent, or recurrent PPUI after implantation of a fixed male sling [74].

4.2.1 Artificial urinary sphincter

The AUS was conceptualized and created by F. Brantley Scott in 1973 [76]. The original AMS 721 model has undergone several modifications and enhancements, leading to the current model AMS 800® (Boston Scientific, Boston, MA, USA), which is the currently established standard for managing moderate to severe PPUI [77]. The AUS comprises a urethral cuff, a pressure-regulating balloon (PRB), and a pump. It is a hydraulic, mechanical device functioning through a circumferential compression of the urethra. The PRB and the cuff come, with different pressure ranges and sizes, respectively, to adapt the device to the patient’s characteristics.

After five decades since its introduction, a considerable number of cohort studies have demonstrated the efficacy and reliability of AUS in terms of continence and quality-of-life improvement [77]. However, significant limitations to AUS use include the device’s mechanical nature, which necessitates adequate manual dexterity and cognition, the persistent need for some pad use in many patients, the worries over potential complications, the need for reoperation due to mechanical failure in about a third of patients, and costs. Consequently, patients should be really motivated for the implantation and informed about the risk of future reoperations.

At our institution, patient preparation is performed following an internal protocol. Antiseptic washing is performed the day before surgery, and trichotomy is done just before surgery. Patients are placed in a high lithotomy position, and chlorhexidine gluconate abdominal and perineal scrub (10 min) is performed. An abdominal-perineal dual-surgical approach is usually used. We implemented a standardized protocol for asepsis to avoid infection, including minimization of operating room traffic, dual single-shot antibiotic prophylaxis (cephazolin and gentamicin), minimum air exposure of the device component, use of double gloves by the members of the surgical team with frequent gloves changes, as well as rinsing of the operative field and PRB with antibiotic solution, use of medicated drapes to isolate skin, meticulous hemostasis, and minimization of tissue dissection. A 12 Fr transurethral catheter is used. In cases of bladder neck contracture, patients are preferentially treated by adopting a two-stage approach with an endoscopic incision performed before the AUS implantation. We usually transpose the cuff tube at the abdominal level and suture the perineum at this point of the procedure to minimize air exposure. The PRB (61–70 cmH2O) is placed intraperitoneally through a McBurney incision, and the pump is implanted in the scrotum. At the end of the procedure, the system is cycled twice, and the pump is deactivated. Skin incisions are approximated with adsorbable running intradermal sutures. The bladder catheter is removed on postoperative day two. Patients are discharged on day three, and the urinary sphincter is activated 6 weeks later [78].

PRB placement has evolved. Some surgeons place it in the space of Retzius. This location has rarely been associated with serious complications, given its proximity to the bowel and bladder. Other authors suggested an alternative ectopic PRB placement via a counter incision in the anterior abdominal wall [79]. Balloon herniation, palpability, and pain represent a possible bothersome complication of the aforementioned locations, thereby, we utilize a deeper pelvic location (intraperitoneally) through a suprainguinal incision.

In clinical practice, one may encounter situations (previous radiotherapy, previous UI surgery, etc.) requiring a different surgical approach.

The bulbar urethra at the level of the bifurcation of the corporal bodies is the most frequently used site for AUS cuff implantation [80]. A distal single or double cuff placement is commonly required in patients undergoing AUS reimplantation following urethral erosion or in those with urethral atrophy at the original cuff site [81]. In cases of compromised urethra due to prior AUS placement, previous radiation therapy, or urethral surgery, the AUS cuff may be placed through a transcorporal approach that protects the posterior wall of the urethra during dissection to decrease the risk of urethral lesions or erosion [82]. The risk of impaired erectile function due to disruption of the tunica albuginea of the corporal bodies is the major drawback of the transcorporal approach that limits its widespread use [83].

The AMS 800 remains the gold standard treatment for PPUI, offering a very satisfactory and predictable continence rate and high patient satisfaction.

Definitions of continence based on pad use are heterogenous in the literature; however, in AUS publications, the “social continence, defined as the use of, at maximum, one pad per day, is the most used quantitative functional outcome.” Van der Aa et al. reported a social continence rate of 79.0% (60.9–100%) [77].

However, AUS implantation is associated with a likely underreported risk of intraoperative urethral lesions and postoperative urethral erosions [77]. The data about infection and erosion rates after AUS placement are inconsistent, with most papers not reporting the erosion and the infection rates separately, counting them as a composite outcome. In a pooled analysis [77] of 12 studies, the mean infection plus erosion rate was 8.5% (3.3–27.8%).

Based on the bi-layered structure with multiple sublayers of the tunica albuginea of the corpora cavernosa, we assessed an alternative “transalbugineal” AUS implantation technique intending to decrease perioperative morbidity while preserving the integrity of the corpora cavernosa [78]. After identifying and splitting the bulbospongiosus muscle, the corpus spongiosum is gently exposed in its anterolateral aspect. Buck’s fascia is incised bilaterally, and the posterior dissection is performed starting 5 mm off the bulbar urethra on both sides, entering the multilayered structure of the tunica albuginea of the corpora cavernosa, thus leaving its external layer attached to the posterior aspect of the urethra. The main aim of our modified technique was to reduce the risk of intraoperative urethral injuries and the risk of postoperative urethral erosion (and consequent infection) due to shallow dissection, without compromising sexual function in potent patients. Our refined implantation technique was demonstrated to be effective, safe, and reproducible, with continence rates similar to those achieved using a conventional approach.

Further potential complications consist of both mechanical and nonmechanical failures, which can manifest as either early or late postoperative complications and may necessitate reoperation. The most common causes of surgical revision are pump migration or malfunction, liquid leakage from the connector, infection, urethral erosion, and urethral atrophy.

Overall, the AUS survival rate is around 90% at 1 year, 57% at 10 years, and 41% at 15 years [84]. A pooled analysis of complications showed mechanical failure in 6.2%, urethral atrophy in 7.9%, and a global reoperation rate for any reason in 26.0% of patients [77]. Urethral erosion or device infection typically results in AUS explantation. A second device implant is associated with a worse outcome [85].

Several competing devices have been introduced in recent years, including the VICTO (Promodon, Cordoba, Argentina) and the Zephyr ZSI 375 (Mayor Group, Villeurbanne, France) systems.

VICTO is an adjustable preconnected AUS. A small silicone balloon regulates the pressure in the occluding cuff, and the control pump has a self-sealing port for pressure adjustment [86]. The system pressure can be adjusted from 0 to 100 cm of water. VICTO +, with an additional stress balloon placed in the preperitoneal region, is available for patients who were unable to interrupt the stream. Thereby, abdominal pressure changes are directly transferred to the urethral cuff [87].

Zephyr ZSI 375 is another all-in-one silicone-elastomeric device [88], without an abdominal reservoir and with an inflatable cuff in which pressure can be adjusted by instilling or abolishing fluid. Neither device is currently approved for use in the US.

4.2.2 Male slings

Male slings are polypropylene meshes positioned over the bulbar urethra via transobturator route [89]. The concept of the male sling was initially proposed by Berry in the 1970s and subsequently refined by Kaufman and Schaefer, resulting in the current medical device used in clinical practice [90]. Slings cure urinary incontinence by simple urethral compression and/or bulb repositioning to restore the preprostatectomy configuration of the prolapsed urethral sphincter complex [91].

Synthetic male slings are becoming increasingly common because they are reasonably inexpensive and do not require mechanical manipulation when voiding. Most experienced urologists recognize that selecting the correct patient is essential for successful treatment. Patients with mild-to-moderate SUI and adequate residual sphincter function, which allows for enough detrusor contraction to overcome the fixed sling impediment and allow voiding, are the best candidates [92].

Male slings are classified as adjustable and nonadjustable based on whether the tension can be adjusted or not after the procedure according to the patient’s continence status [51].

Commercially available adjustable male slings are Argon (Promedon, Cordoba, Argentina), Re-Meex (Neomedic, Barcelona, Spain), and ATOMS (AMI, Feldkirch, Austria), while current nonadjustable male slings are AdVance (Boston Scientific, Minnetonka, MN, USA), I-STOP TOMS (CL Medical, Lyon, France), and Virtue (Coloplast, Minneapolis, MN, USA).

There are no studies that compare individual devices. As a result, determining the success rate of operations is difficult, and judging which sling system is superior is challenging [93].

AdVance XP sling is the evolution of AdVance sling (Boston Scientific, Marlborough, MA, USA), a retrourethral sling that contains polypropylene mesh. It is placed via a transobturator approach around the proximal bulbar urethra. To accurately position the sling, the central tendon of the perineum must be released. The mesh is then attached to the bulbous urethra, and the tension is applied so that the membranous urethra can be relocated further proximally. Continence is achieved through a 3–4 cm proximal elevation of the bulbar urethra [94].

The AdVance XP model, launched in 2010, has improved stability due to tensioning fibers, chevron anchors, and Tyvek (DuPont, Wilmington, DE, USA) liners. Furthermore, the implantation needle was modified to facilitate placement [95].

In our practice, we utilize a bulbospongiosus muscle-sparing surgical technique for the insertion of the AdVanceXP sling, with the aim to decrease postoperative complications (acute urinary retention and urethral erosion) [96]. The muscle-sparing approach consists of placing the sling directly on the bulbospongiosus muscle, unlike the standard technique, which requires the opening of the bulbospongiosus muscle and the placing of the sling on the underlying corpus spongiosum. The preservation of an intact and healthy proximal bulbar urethra is particularly desirable in failed patients requiring subsequent AUS implantation [96].

There is level 1 evidence that male sling can cure or improve PPUI with an overall success rate between 60 and 80% [97, 98]. Success is inversely correlated with SUI severity, with mild incontinence achieving success rates of 80–90%, even outperforming the AUS [99]. However, for those with moderate SUI, the AUS outperforms the sling, with sling success rates ranging from 32 to 83% [48, 75]. The severity of SUI has been associated with worse outcomes; therefore, patient selection is the key to success [94].

Failure rates after sling placement range from 15 to 45% and current knowledge of predictors of sling efficacy is limited [100].

Literature reports a postoperative complication rate ranging from 1 to 45% [101]. Perineal pain is the most common complaint, with an estimated rate as high as 45%. Urinary retention rates range from 2 to 23%, depending on the type of sling selected. Other uncommon complications include urethral erosion and infection. Revision rates are reported at approximately 1% [93, 94].

A recent noninferiority randomized controlled trial compared synthetic slings with AUS. The former was comparable to the latter in terms of continence rate improvements, symptoms, quality of life, and treatment-related satisfaction [98].

4.2.3 Peri-urethral balloons

The ProACT^® (Uromedica, Inc., Plymouth, MN, USA) is a noncircumferential compressive device consisting of two silicone balloons that are implanted by a trocar via two small perineal incisions and are placed under fluoroscopic guidance on each side of the bladder neck, close to the vesicourethral anastomotic site. An outpatient procedure fills the balloons, resulting in mechanical compression of the urethra [102].

The potential benefits of the ProACT device include technical reliability of implantation, low morbidity, a low price, the absence of circumferential urethral compression, and the possibility to modulate the degree of urethral compression [103].

The efficacy is reported to be 55% (30–75%), but more than a third of patients were not satisfied with the outcome of the surgery [104]. The success rates are negatively impacted by the severity of incontinence and a prior history of radiation therapy, which some authors consider a contraindication [74, 105].

There is currently no direct recommendation in the European guidelines for using ProACT. These device implantations should be exclusively performed at specialized centers due to the specific surgical technique, the complexity of indications, and the potential risks of erosion, mechanical failure, and subsequent reoperation, with an estimated explantation rate of 25% [74].

4.2.4 Bulking agents

In patients with PPUI persistent and refractory to conservative management or in patients unfit for more invasive surgical treatment, bulking agents are an option that can be chosen [106].

Among all the bulking agents, polytetrafluoroethylene (Teflon) and bovine collagen have been the first two agents used. More recent elements are represented by adipose tissue (1989) and stem cells (2007) [107].

Based on a systematic review by Toia et al. [106], bulking agents can improve continence rates, at least in the short term.

Bulking agents are injected endoscopically into the sphincteric complex, increasing the sphincter’s coaptation and resistance to flow [65]. A controversy exists on injection volume and site, leading to variable functional improvements between different centers [106].

According to a recent meta-analysis, which compared the different devices used for treating PPUI, bulking agents are associated with the lowest improvement in continence after treatment. In addition, the more the injections are, the lower the continence rates and improvements are [108].

5. Conclusion

PPUI is not an infrequent event that negatively impacts a patient’s quality of life and is related to considerable economic pressure. A wide range of treatment options is available, ranging from conservative methods to invasive surgical procedures.

PFMT is suggested for the initial management of PPUI, while anticholinergic drugs are used for urgent symptoms.

AUS was the preferred treatment for patients with consistent PPUI for several decades. Male slings are currently becoming a valuable alternative for patients with mild-to-moderate PPUI. A meticulous preoperative workup should be conducted when planning a male PPUI surgery and the surgical approach should be chosen based on the disease’s severity. Patients with an unclear or inconsistent history should undergo further objective workup, including cystoscopy and/or urodynamics. Ongoing research will help to stratify patients and sustain preoperative decision-making.