Radical prostatectomy (RP) invariably results in at least a small percentage of men suffering from persistent post-prostatectomy incontinence (PPI). PPI has a detrimental effect on a man’s quality of life, even if only suffering from mild-severity stress urinary incontinence (SUI).1 Initially following catheter removal, nearly 100% of patients will experience at least transient PPI. This tends to dramatically improve over the course of the first 12 months and some men will experience further improvement as many as 3 years postoperatively.2-5
After failure of conservative measures and enough time for natural continence recovery, men with persistent PPI should be counseled on the breadth of treatment options available to them. Artificial urinary sphincters (AUS) remain the gold standard surgical incontinence procedure with long-term durability and patient satisfaction.6,7 Guidelines acknowledge this fact, but also point out the other options that patients perceive as being less invasive and potentially more desirable, such as suburethral slings.8 In fact, patients with PPI who are given a choice between a sling or an AUS will more often select a sling procedure despite a recommendation to the contrary.9 This review outlines the history of male slings and highlights developments within the past decade.
Bulbourethral slings were designed to be an alternative to artificial sphincters in the treatment of SUI. Initial models used either allograft or polypropylene mesh and achieved continence through urethral compression (Table 1). Schaeffer first described a male urethral sling using Dacron bolsters anchored to the rectus fascia.10 Later, the InVance™ (Boston Scientific, formerly American Medical Systems, Marlborough, MA) bone-anchored sling was developed, which utilized titanium screws to anchor mesh to the inferior pubic rami and acted through urethral compression.11 Intermediate and long-term results with this device showed sustained 60% to 65% cure rates and nearly 70% to 87% improvement rates at up to a mean 41 months of follow-up.12,13 Since the development of new sling designs, the InVance male sling is currently off the market and not available for implantation.
In 2006, Rehder and Gozzi developed the AdVance™ male sling system (Boston Scientific, formerly American Medical Systems, Marlborough, MA), a novel sling design for the treatment of SUI.14 This sling is a polypropylene mesh placed using a trans-obturator (TO) technique. The procedure was initially demonstrated in a cadaver series, which showed that the proximal urethra was repositioned into the pelvic outlet 3 to 4 cm with a retrograde leak point pressure (RLPP) greater than 60 cm H2O following tensioning of the mesh. The group subsequently placed the AdVance sling in 20 men with SUI. After tensioning of the sling, video urodynamics showed an increase in urethral closure pressure from 13.2 to 86.4 cm H2O and an increase in membranous urethral length from 3 mm to 17.2 mm. At 6 weeks post-operatively, 40% of the patients were not using pads. An additional 30% were improved and only using 1 or 2 pads per day. Rather than the compressive mechanism of the InVance sling, it was theorized that the sling was effective secondary to a repositioning of the proximal urethra thereby augmenting residual sphincter function. In 2010, a second generation AdVance XP™ male sling system was released that incorporates mesh barbs to limit sling slippage and loosening. This is currently available in Europe and Australia but has not been Food and Drug Adminiastration (FDA) approved for use in the United States.
I-Stop® TOMS® (CL Medical, France) is a more recent fixed mesh system. It acts in a similar fashion to the AdVance sling and is also placed through a pure TO approach.15 Finally, the Virtue® sling (Coloplast, Humlebaek, Denmark) is a fixed mesh suburethral sling, developed by Comiter and colleagues in 2012. It incorporates both TO and pre-pubic arms.16 It is purported to function through urethral compression and bulbar relocation.
In addition to fixed mesh systems, several adjustable slings have been developed, although none has FDA approval for use in the United States (Table 2). These adjustable devices offer the purported benefit of being modifiable after initial placement in cases with persistent incontinence. The two most commonly used adjustable slings are Argus (Promedon, Cordoba, Argentina) and ReMeex (Neomedic, Barcelona, Spain).17,18 Both utilize a retropubic rather than TO approach and adjustments are made through a suprapubic incision under local anesthesia. More recently, the adjustable trans-obturator male system or ATOMS® (A.M.I., Vienna, Austria) was introduced, which functions as a purely TO adjustable device.19 Argus also has an adjustable TO version named the Argus-T.
All patients presenting with PPI should undergo a thorough history and physical examination, voiding diary, evaluation of post-void residual urine volume, and a urinalysis. As self-reported daily pad usage is only moderately correlated with true volume of urinary leakage, 24-hour home pad weight testing may be helpful in assessing the degree of incontinence.20
Although the main etiology of PPI is external sphincter dysfunction, it is important to differentiate between SUI and urge incontinence (UI). De novo detrusor overactivity has been found in 15% of patients following RP and tends to improve with time.21 Men with persistent (longer than 12 months) PPI without improvement using conservative measures may be offered surgical intervention. At that time, consideration for more invasive testing must be discussed with the patient. Cystourethroscopy will rule out urethral or bladder pathology and evaluate the compliance of the urethrovesical anastomosis. A repositioning test may be done to demonstrate adequate urethral coaptation for patients being considered for a purely TO sling approach. Finally, urodynamics (UDS) should be obtained in all men presenting for surgical treatment of PPI. Pressure-flow UDS can uncover concurrent bladder dysfunction, assess degree of intrinsic sphincter deficiency, and may aid in the selection of a surgical approach. In one prospective study, de novo bladder outlet obstruction, reduced bladder compliance, and detrusor hypocontractility were detected 8 months following RP in 7.4%, 32.3%, and 51% of patients, respectively.21
There is not yet a unified definition of an ideal suburethral sling candidate for PPI treatment. In general, however, men with mild to moderate incontinence will fare better than those with more severe leakage.22 Additionally, worse outcomes have been observed in men with prior radiation, urethral stricture disease, and obesity, although, none are absolute contraindications to sling placement.8,22,23 Given that manual dexterity is not required for sling placement, those men with functional limitations that prohibit them from manipulating an AUS pump, even if severely incontinent, should be offered sling placement.
Procedure. The AdVance male sling is a macroporous monofilament polypropylene mesh designed for a pure outside-in TO approach with the body of the sling placed at the bulbar urethra. With the patient in dorsal lithotomy position, a midline perineal incision approximately 5 cm in length is made. The dissection is carried through the subcutaneous tissue to the bulbospongiosus (BS) muscle. The BS muscle is divided in the midline to expose the corpus spongiosum (CS), which is mobilized distally, laterally, and inferiorly to the central tendon. The central tendon is marked with an absorbable stitch or marking pen and then dissected off the CS until it is no longer palpable.
Separate bilateral incisions are made 1 to 2 cm below the adductor longus tendon and lateral to the ischiopubic ramus. The Advance helical needle is held at a 45° angle to the patient and placed straight through the incision. Two “pops” are felt. After the second “pop,” the needle is turned approximately a quarter turn. Prior to bringing the needle through the fascia, the surgeon’s hand is dropped and the needle is brought out as high as possible in the triangle between the ischiopubic ramus and the urethra. The mesh is secured to the needle and then brought back through the incision. The central portion of the mesh is fixed to the CS. Tensioning of the sling is done by pulling firmly on both arms of the sling. Cystoscopy is performed to confirm coaptation of the external sphincter. Once coaptation is confirmed, the BS muscle and perineal wound is closed.
Results. Compared with the AUS, which has follow-up data that is measured in decades, follow-up for the AdVance sling is modest, but growing. Mid-term outcomes have shown durable results compared with initial reports.22,24 In their original study, Rehder and Gozzi reported a cure rate of 40% and an improved rate of 30%.14 These numbers have been used as a benchmark to which others have compared their results and most have met or exceeded that standard.
As data following AdVance placement continues to mature, results with more extended follow-up has been described by several centers. In 2012, Rehder and colleagues reported 3-year outcomes following AdVance sling placement (mean, 40.1 months of follow-up) on 156 consecutive patients.25 Patients were defined as having mild (1-2 pads/day), moderate (2-4 pads/day), or severe (≥5 pads/day) incontinence. No patients were excluded based on leakage volume. Most patients (64.1%) had mild or moderate incontinence, whereas 35.3% had severe incontinence. Success was defined as cured (0-1 pad for security reasons only) or improved (1-2 pads per day + 50% reduction in daily pad usage from baseline). The authors reported a durable cure rate of 53.8% at 12 months and 53% at 36 months. Overall success rate was 76.9% and 76.8% at 12 and 36 months, respectively. Complications were reported by most patients, but were nearly all mild and transient, including perineal pain (50.0%), urinary retention (9.0%), and dysuria (4.5%) being the three most common.
The authors have reported an extended outcome analysis on 102 patients followed for an average of 36.2 months with similar definitions for success.26 Overall success at final follow-up was 62% (40% cured and 22% improved). Notably, the results did not confirm the durability reported by Rehder and colleagues. There was a steady decline in patients who were cured following AdVance sling placement over time until 30 to 36 months post-operatively. This translates into a decrease in the percentage of patients cured from 58%, 43%, and 40% at 12-month, 24-month, and final follow up, respectively. Overall success rates also declined to 74%, 63%, and 62% at those same time points. Complications in the series were mild and compared with other reports. Transient urinary retention was seen in 11.8% and mild scrotal/groin pain in 5.9%. One surgical site infection required mesh explantation in a patient with chronic methicillin-resistant Staphylococcus aureus (MRSA) infections. The rate of patients lost to follow-up was not addressed in this study, so it is unclear if this trend reflects mechanical failure of the AdVance sling over time or a selection bias in which a greater proportion of patients with recurrent or persistent incontinence are retained.
Others have also questioned the long-term durability of the AdVance sling. Li and associates noted decreased success from 87.3% to 62.5% and an increase in mean pad use from 0.8 to 1.7 pads per day at 2 years following sling placement.27 Interestingly, patient perceived outcomes were durable despite using more pads per day. It is possible that this discordant trend reflects a selection bias in which patients initially desiring sling placement remain satisfied because their expectations were met. Alternatively, patient satisfaction may be independent of returning incontinence.
To improve continence durability, a modified AdVance XP™ sling was approved for use in Europe in 2010 but has not yet been approved by the FDA in the United States. Updates to the sling include chevron anchors on the sling arms, updated mesh weave for stabilization, longer sling arms, and an updated Tyvek® lining to prevent sheath tearing on removal. In a prospective multi-center study, Bauer and associates placed AdVance XP slings in 115 carefully selected patients.28 After a follow-up of 24 months, 68.8% of the patients were cured and 22.5% had improved. An extended follow-up to 36 months showed stability and durability with 66% of patients cured and 23.4% improved. However, only 40.9% of the study population reached a follow-up of 36 months and there was no comparison group.
More data is necessary to determine the exact durability and success rates that can be expected by a general urologist performing this procedure with either version of the AdVance sling. It will be interesting to review 5- and 10-year outcomes following AdVance sling placement when they become available.
Procedure. Different from the pure TO approach of the AdVance male sling, the Virtue sling has two additional prepubic arms to increase urethral compression. It is composed of a macroporous monofilament polypropylene mesh. Following perineal dissection, the BS muscle is left intact, but the central tendon is taken down. The TO arms are then passed using an inside-out approach. Trocars for the prepubic arms are then passed from superior to inferior. The TO arms of the sling are tensioned first followed by the prepubic arms. Tensioning should be performed until a RLPP of 60 to 70 cmH2O is achieved.16 After appropriate sling tensioning, the TO arms are tunneled back to the perineum and the prepubic arms are sutured to the periosteum of the pubic symphysis. For patients with residual bothersome leakage, revision surgery can be performed to tighten the sling.29
Results. The initial publication of the Virtue sling by Comiter and colleagues primarily focused on improvement in RLPP.16 They showed that placement of the sling led to an average 106% increase in RLPP from baseline (33.4 cmH2O to 68.8 cmH2O).
This initial study was followed up with a well-designed multi-institutional 12-month efficacy trial.30 In this initial group, the sling arms were not fixed, but rather cut flush with the skin at their exit sites. Using this technique, the authors noted a less than optimal result, specifically noting substantial reductions in efficacy over time. In this cohort, objective success (50% reduction in pad weight) was only 41.9% at 12 months. The procedure was subsequently altered to include the method of sling fixation described above. With this small procedural modification, they were able to demonstrate significant improvements in efficacy. Objective success at 12 months using this technique improved to 79.2%. This improvement was despite 33% of the cohort presenting with severe incontinence at baseline. Cure rates were 46% at 12 months and subjective satisfaction (predefined as “very much better” or “much better” on a validated patient symptom improvement questionnaire) was 70.9%. Complications were generally mild. Genital paresthesia was described in 12.2% to 19.4% and perineal pain in 12.9% to 14.3%. All cases of pain resolved spontaneously. All but two cases resolved by 6 months post-operatively.
Additional objective success was demonstrated in a 2017 prospective, single-institution study involving 29 consecutive patients.31 At 12-month follow-up after Virtue sling placement, mean 24-h pad weight decreased significantly (128 g vs 2.6 g, P < 0.05). Complications were reported in 17 patients (58.6% of cohort), but all were Clavien-Dindo grade 1. Approximately 17% of patients reported scrotal pain post-operatively, but no slings were explanted.
In contrast, McCall and colleagues reported a 68% failure rate in 31 consecutive patients who underwent Virtue placement by a single surgeon.32 Median follow-up was 55 months. Failure was defined as no change in post-operative pad use, failure to reduce leakage to <2 pads/day, placement of AUS, and/or sling explant. Seven patients (22%) underwent sling removal for pain or for procedural failure.
There have been few publications detailing the long-term safety and efficacy after Virtue placement. Prospective, multi-institutional studies with longer follow-up are needed to further clarify durability, need for revision surgery, and concerns regarding chronic pain.
Procedure. The I-Stop TOMS sling is placed via a pure TO approach, like the AdVance sling. However, the BS is left intact and the central tendon is not incised. The helical trocars are passed in an outside-in fashion. The recommended site of entry in the groin is 4-cm inferior to the adductor longus tendon, slightly different than that which is recommended for other TO sling placements. Tensioning is performed sufficiently to indent the BS muscle.
Results. A multi-institutional trial evaluating 12-month outcomes following I-Stop TOMS placement in 122 patients was reported by Grise and colleagues in 2012.15 Out of the entire cohort, only 103 patients (84.4%) completed the entire 12-month follow-up and of those only 69 had data relating to pad usage. In this limited cohort, 87% showed improvements in pad use and 59.4% were dry. Pad weights on a 1-hour pad test were available in only 36 patients at 12 months but did show a mean reduction from 105.1 g to 11.3 g (P ≤ 0.01). On subjective satisfaction, 91.2% were satisfied or very satisfied with their outcome at 12 months.
In contrast, a recent retrospective, multi-institutional study raises serious questions about the long-term durability of the I-Stop TOMS.33 One hundred patients with mild to moderate PPI (24-h pad test <400 g) and no history of pelvic radiation were followed for a total of 58 months. After 1 year, 40% of patients were dry and 77% were socially continent (0 to 1 pad/day). However, after 5 years only 15% were dry and 22% were socially continent.
Procedure. The Argus adjustable sling is a retropubic placed sling through a combined abdominal and perineal approach. The body of the sling is comprised of a 4.2 × 2.6 cm silicone foam cushion, silicone arm columns, and fixation washers. Via a perineal incision, the BS is exposed and left intact. The urethra is not mobilized off the central tendon. A transverse abdominal incision is made sufficiently large to clear off an area of rectus fascia. The included trocars are passed through the retropubic space and perforate the rectus fascia. Included washers are attached to suspend the arms and allow sling tensioning based on cystoscopic RLPP. Postoperative adjustments of the suprapubic arms can be made under local anesthesia if necessary. The TO version of this sling (Argus-T) utilizes helical trocars and 3-cm incisions in each groin. Groin dissection is required to expose the obturator membrane, as this is where the sling washers rest for suspension and tension adjustment.
Results. Romano and colleagues published the initial report of Argus sling placement in 48 men with SUI in 2006.18 At an average 7.5 months of follow-up, the overall success was 83%. Success was defined as cured (dry, no pads) or improved. Urethral erosion occurred in 6% of patients and infection in 4%, each requiring sling explantation. Subsequently, there have been two publications of mid-term outcomes with the Argus sling from different centers.34,35 Continence outcomes in these series were reasonable with 52% to 79% dry at an average follow-up of approximately 27 months. However, complications were not minimal. Device explant rates for erosion or infection ranged from 11% to 15.8% despite some patients receiving less tensioning on the sling in a direct attempt to prevent this outcome. Additionally, urethral strictures were reported in 12%, a complication not seen with previously mentioned fixed mesh slings.34 Dalpiaz and colleagues reported an explant rate of 35% secondary to erosion, infection, device dislocation, retention, or pain.
Most recently, Siracusano and colleagues reported a prospective, multi-institutional study on 182 patients following Argus-T sling placement.36 At the median follow-up of 22 months, 33% of patients were cured and 53.2% were improved. When broken down by degree of pre-operative incontinence, success rates were 95% (57% cured, 38% improved) for mild incontinence (1-2 pads/day), 78% (33% cured, 45% improved) for moderate incontinence (3-5 pads/day), and 70% (25% cured, 45% improved) for severe incontinence (>5 pads/day). Despite these positive results, 42.9% of patients underwent at least one revision procedure, which required an additional spinal or general anesthetic. Revision procedures were associated with worse outcomes, regardless of pre-operative incontinence status. The overall complication rate was 14.6% with 9.3% of slings explanted.
Although it appears the Argus sling may be effective in the short-term, significant improvements in the rate of postoperative complications must be seen before the device can be recommended for patients with PPI.
Procedure. The male Remeex system is composed of a monofilament suburethral sling, a suprapubic mechanical regulator, and two monofilament traction threads passed through the retropubic space. Approach to placement of the male Remeex system is like the Argus retropubic sling, requiring both perineal and suprapubic dissection. The perineal membrane is perforated with scissors, allowing blunt finger dissection in the space of Retzius. A 60° modified Stamey needle is then passed behind the pubic symphysis from superior to inferior. If cystoscopy confirms the absence of a bladder or urethral perforation, the traction threads are attached and brought back through the suprapubic incision. The traction threads are attached to the varitensor in the suprapubic incision and the sling is left loose. The external manipulator is connected, and the abdominal incision closed. On postoperative day 1, the bladder is filled and Valsalva maneuvers are performed to assess for leakage. The external manipulator is used to tighten the sling until leakage ceases without causing urinary retention. Further adjustments can be made, if necessary, under local anesthesia.
Results. There have been four single case series of more than five patients evaluating the male Remeex system. In 2007, Sousa-Escandón and colleagues evaluated the sling in 51 men with variable degrees of incontinence.17 At a mean follow-up of 32 months, 64.7% of patients were dry and 19.6% had greater than 50% improvement in preoperative pad counts. No objective measure of incontinence severity was studied. To achieve this degree of subjective continence, 86.3% of patients required a second sling manipulation and 33% required a third or fourth manipulation after initial sling tensioning. In 2011, the male Remeex system II (MRS-II) was introduced with a larger base plate to maintain the traction threads in a more lateral position. In a 2016 study that evaluated 24 men with PPI implanted with the MRS or MRS-II, the average number of adjustments was 2.41 ± 1.52. When analyzing for just men carrying the MRS-II, the average number of adjustments significantly improved to 1.12 ± 0.83 (P < 0.001).37 Two explants were performed due to infection of the system during adjustments.
Procedure. The ATOMS system consists of an implant with a silicone inflatable cushion and trans-obturator macroporous, monofilament polypropylene mesh arms (Figure 1). Previous generations utilized a titanium port for volume adjustments, which could be placed in the inguinal region or scrotum. The current third generation involves a pre-attached fully silicone-covered scrotal port (Figure 2). Device placement is performed through a midline perineal incision like other TO slings. The BS muscle is exposed and left intact, as is the central tendon. Helical trocars are used to pass the mesh arms outside-in through the TO space. The arms are secured to the silicone cushion under tension. The device has preplaced sutures on the silicone pad for mesh arm fixation for this purpose, creating a “four-point” fixation system. Subsequent modifications to the pad volume can be made through percutaneous access of the scrotal port and instillation of additional fluid.
Results. Friedl and colleagues recently published the largest study to date regarding ATOMS placement.38 In this retrospective multi-center study involving 287 men, overall success rate was 90% with a cure rate of 64%. Median follow-up was 31 months and median number of adjustments was 3. There was a significant decrease in 24-h pad test (400 mL/day to 18 mL/day; P < 0.001) and 24-h pad use (4 pads/day to 1 pad/day; P < 0.001). Explant rate was 20% with local titanium intolerance in the older generations (41%), leak/dysfunction (30%), and infection (22%) the most common etiologies.
SUI following RP remains a serious detriment to a man’s quality of life. Suburethral slings offer a perceived minimally invasive alternative to the AUS with modest dry rates and overall success rates approaching 80%. Proper pre-operative selection is paramount. Durable objective and subjective outcomes are better in patients with mild-moderate incontinence, absence of bladder dysfunction, and no history of pelvic radiation. Several sling options are currently available, including fixed mesh pure TO approaches in the AdVance and I-Stop TOMS slings. The Virtue Quadratic sling includes both TO and prepubic arms. Recent studies have raised concerns regarding the durability of both I-Stop TOMS and the Virtue slings. ATOMS and Argus-T are adjustable TO devices that have showed promising short-term results. Finally, two retropubic adjustable slings are available (Argus and Male Remeex System). Early results in the Argus studies are concerning for increased rates of urethral erosion and infection requiring explantation.
Despite a plethora of new literature over the past decade, there is no consensus on which sling modality is the most effective. Heterogeneity in patient selection, poorly defined baseline incontinence, variability in the definition of success, and relatively short follow-up have limited generalizable conclusions and made it difficult to compare individual slings. Complications for the fixed mesh slings are generally mild and transient. In contrast, the adjustable slings have a 10% to 20% explantation rate. This difference in complication rate may be reflective of data from older generation adjustable slings, a more morbid retropubic adjustable sling implantation (need for perineal and abdominal incisions), or the need for multiple revision procedures.
Currently, the AdVance sling is the most commonly performed male sling procedure and given its durability, it is our sling of choice. As data matures from each of these sling designs, the ability to select the optimal sling for each patient will improve.
Source of Funding: None
The views expressed in this manuscript are those of the authors and do not reflect the official policy or position of the Department of the Navy, Department of Defense, or the United States Government.
The authors have no relevant financial relationships with any commercial supporters.