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Male Slings: Past, present, and Future.
Issues in Incontinence: Spring/Summer 2008
By Edward Zoltan, MD and Alexis Te, MD
Incontinence following prostatectomy can be a devastating complication significantly impacting quality
of life. The prevalence of post-prostatectomy urinary incontinence (PPI) varies from 2.5%–87%, with
2%–10% reported in more recent series.1,2 Incontinence can also occur in 1% of patients undergoing
surgical treatment for benign prostatic hypertrophy. 1
Although the incidence of PPI has decreased with better understanding of neurovascular anatomy and
the advent of the robotic prostatectomy with its novel techniques of urethral reconstruction,3 it
continues to be one of the most feared complications after surgery. Part of the reason for the wide
range in reported PPI lies in the use of different definitions of incontinence with accompanying
divergent methods of assessment.
Evaluation
The evaluation of patients with PPI should begin with a comprehensive history, including onset,
duration, evolution, cause of the leakage, and the number of pads used. It is important to assess how
the incontinence affects daily activities and if the patient is bothered by it. The pad-weight test may be
used to objectively assess the severity of incontinence. Any history of surgery or radiation should be
noted. A voiding diary can be helpful to quantify fluid intake and functional bladder capacity. Physical
examination is performed with emphasis on neurological assessment of the S2-S4 spinal segments,
including anal sphincter tone, perineal sensation, and bulbocavernosus reflex. Abdominal palpation may
detect a distended bladder with overflow incontinence. Urodynamic evaluation may differentiate
between the various causes of PPI in addition to ruling out poor bladder compliance,high-pressure
detrusor overactivity during filling, and bladder obstruction during the flow portion of the study. Bladder
capacity is also measured, as most patients with severe incontinence have low functional bladder
capacity because of poor storage ability.
Management
Male stress urinary incontinence (SUI) may be addressed by numerous established methods. These vary
from relatively noninvasive methods of pelvic floor stimulation or biofeedback to progressively more
invasive methods involving the use of various injectable bulking materials, bulbourethral slings, and the
artificial urinary sphincter. Since spontaneous improvement of urinary incontinence may take up to 12
months, it has been recommended that surgical intervention be postponed in men with PPI until 12
months after the prostatectomy.1
Other contraindications to surgical intervention include the inability to operate a device, and any
disorders jeopardizing the upper urinary tract, including diminished bladder compliance, frequent highpressure detrusor contractions, or vesicoureteral reflux at low intravesical pressures. Any urinary tract
abnormalities requiring future transurethral management may also be considered relative
contraindications to outlet surgery. Stress incontinence surgery is not recommended in patients with
untreated low-volume detrusor overactivity that would not permit adequate symptomatic
improvement. Chronic infection of the urine or skin, anatomic abnormalities, immunosuppression, and
poor urethral tissue quality are also relative contraindications.4
Artificial urinary sphincter
The artificial urinary sphincter (AUS) is the gold-standard treatment for postprostatectomy SUI. The AMS
800 device (American Medical Systems, Minnetonka, MN) provides acceptable social continence in
approximately 90% of patients. Introduced over 30 years ago, the device has continually evolved to its
current and sophisticated form. It is widely used in clinical practice, and over 100 000 devices have been
implanted worldwide.
Several complications may occur in AUS patients. Urethral erosion occurs in 1%–3% of patients and may
be precipitated by infection, excessive cuff pressure, decreased vascularity from prior radiation, an
undersized cuff, or traumatic catheterization through an activated cuff. 5,6
Infection occurs in 1.8%–10% of patients.7 AUS revision rates currently hover around 9%, with an
expected 5-year survival of narrow-backed AUS of 75%.7 Persistent stress incontinence may occur in up
to 15% of patients after AUS insertion.8
Urethral atrophy may cause residual incontinence despite AUS placement, with an incidence of 3%–9%;
management options include downsizing the cuff or placing a tandem cuff. 6 Post-AUS SUI may also be
due to an excessively loose cuff or low reservoir pressure.
Bulking agents
Introduced in 1993, bovine glutaraldehyde cross-linked collagen (Contigen; CR Bard, Covington, GA) has
been used extensively as a bulking agent in the treatment of intrinsic sphincter deficiency in men.
Collagen implantation is well tolerated and has a low complication rate. Although recommended for
mild to moderate male SUI, repeated injections are often necessary to establish and then maintain
continence; indeed, the longterm results of such injection therapy have been disappointing. 9,10
It has been reported 11 that the best results can be obtained in patients with mild degrees of
incontinence and a preoperative Valsalva leak-point pressure > 60 cm H2O.
Previous male slings
Before the AUS was introduced, a variety of urethral compression procedures was attempted to control
urinary incontinence. One of the first prosthetic devices was described by Berry 12 in 1961. It was an
acrylic device placed beneath the bulbocavernosus muscle, designed to kink and compress the bulbous
urethra at a point just distal to the urogenital diaphragm. The procedure was then modified to include
the use of stainless steel sutures, passed through drill holes in the ischial and pubic rami. 13 However,
high rates of perineal pain and fistula formation in the presence of only modest success led to the
abandonment of the Berry prosthesis. 14
In 1970, Kaufman 15 described a surgical method for compressing the urethra. In this Kaufman type-I
anti-incontinence procedure, the penile crura were crossed over the bulbous urethra to produce
urethral compression, but success rates were low (30%). In the Kaufman type-II procedure, 16 the crura
were approximated in the midline using a polytetrafluoroethylene mesh tape. The synthetic tape was
folded in such a manner as to compress the bulb of the urethra. Success rates increased to 50%. The
Kaufman type-III procedure 17 used a silicone-gel-filled hemispherical prosthesis, surrounded by external
velour of polyurethane and 2 polyurethane straps, leading to success rates approaching 70%. Kishev 18
next described a combined abdominoperineal approach utilizing a pliable prosthetic wad under the
bulbar urethra, with tension provided by nylon sutures that are passed through the retropubic space
and secured over small Marlex pledgets above the abdominal fascia. The Kaufman and Kishev
prostheses ultimately fell out of favor, however, because of high failure rates, infectious complications,
pelvic pain, and the introduction of the AUS.
Based on the Kaufman and Kishev techniques, Clemens et al. 19 described a bulbourethral sling
procedure in 64 men with severe PPI. A suture with a series of tetrafluoroethylene bolsters was passed
underneath the bulbar urethra with a Stamey needle and brought through suprapubically lateral to the
urethra and bladder neck, thus compressing the bulbar urethra. At a mean followup of 18 months, 56%
of patients became dry, while 8% were significantly improved; this resulted in a 38% cure rate and a 49%
pad-free rate. However, sling revision was required in 21% of patients, while bolster removal was
necessary secondary to infection or erosion in 6%.
Moreover, 52% of patients complained of chronic perineal numbness or pain, although this decreased to
18% at 4-year followup. 20 This discomfort was most likely due to high-pressure entrapment of pudendal
nerve branches during blind suprapubic suture passage.
Current male slings
More recently, bone-anchored perineal male slings were introduced by Franco and Baum 21 and Madjar
et al. 22 These were later popularized by Comiter 23 and Rajpurkar et al. 24 The use of bone anchors
obviates the need for blind suprapubic transfer of sutures to achieve bulbourethral compression and
eliminates the need for abdominal incisions. Such slings utilize 6 titanium 5-mm screws drilled into the
anteromedial aspects of each descending pubic ramus using the InVance bone drill (InVance, American
Medical Systems) (see Figure 1). These screws are preloaded with a pair of number-1 polypropylene
sutures. The topmost bone screws are placed just beneath the junction of the descending ramus and
pubic symphysis; the remaining sutures are placed 1 cm apart on each side. A rectangle (4 x 7 cm) of
polypropylene mesh alone or in combination with the dermis as a composite graft is used as sling
material. After 1 side of the sling is anchored to the pubic ramus, sling tension is adjusted, guided either
by the retrograde leak-point pressure method or, if the patient is awake, by the simple cough method.
The sling is then tied down to the opposite pubic ramus.
Persistent scrotal/perineal pain is a relatively unusual occurrence (10%); however, small pudendal nerve
branches do travel along the medial aspect of the descending pubic rami and may be injured during
dissection or screw insertion. Complaints of pain without evidence of infection should be managed
conservatively with narcotics and anti-inflammatory medication. If pain persists after 6–8 weeks of
conservative management, consideration should be given to sling removal. One must always consider
the risk of osteomyelitis or osteitis pubis in these cases. As is the case with pubic symphyseal bone
anchors in women, bone anchor removal is a difficult procedure and usually recommended only in cases
of bony infections.
Unlike the AUS, which circumferentially compresses the urethra—thereby interfering with venous blood
flow and thus predisposing the urethra to atrophy and even erosion—the male sling compresses only
the ventral aspect of the bulbar urethra, leaving the dorsal and lateral blood flow intact. Moreover, the
bulbospongiosus muscle and other tissue are left intact over the urethra, serving as a cushion between
the urethra and the sling and further minimizing the risk of erosion. The infection and erosion rate for
perineal slings is low (2.1%), with an accompanying low rate of revision caused by bone anchor
dislodgement (4.2%). 25
Another advantage of the male sling over the artificial urinary sphincter is that voiding occurs sans
device manipulation. There is no postoperative activation necessary: as soon as the urinary catheter is
removed, normal voiding may occur. In addition, without the hydraulic system as found in the AUS, the
risk of mechanical malfunction is minimized. Sling implantation also does not preclude later AUS use. 26
In this study where an AUS was placed after male sling failure, 72.7% of patients were dry following AUS
implantation, while another 9.1% reported improved continence. No complications were reported
during urethral dissection in patients with prior male sling procedures.
Excellent cure rates have been reported with the bone-anchored perineal sling, ranging between 70%
and 90%. 21-24
Comiter recently reported 25 intermediate-term results with a median followup of 48 months: mean pad
usage decreased from 4.6 ± 2.1 to 1.0 ± 1.7 pads per day (p < .01); 65% were considered cured of
leakage while another 15% were significantly improved.
Similar results were obtained by Rajpurkar et al. 24 who reported a success rate of 74% in patients with a
mean follow-up of 24 months.
Onur et al. compared the use of synthetic with absorbable graft material in perineal slings. In a study 27
of 46 men, success rates were significantly higher in patients receiving synthetic mesh, either alone or as
composite graft, compared with patients receiving absorbable material alone (75% vs. 97% vs. 0%
respectively, p < .05). All patients with failed procedures had absorbable graft-type slings. Patients with
mild to moderate incontinence (< 5 pads/ day) had a significantly better outcome compared to those
with severe incontinence (≥ 5 pads/day).
The future of male slings
A new transobturator male sling system (AdVance, American Medical Systems) (see Figure 2) has
recently been approved for use in the United States. With this system, a midline perineal incision is
made, exposing the bulbospongiosus muscle, which is then split centrally and retracted laterally. The
dissection is extended to the perineal body. After exposure of the urethral bulb, blunt-finger dissection
is used to identify the space between the corpora cavernosa laterally and the corpus spongiosum
medially. A small skin incision is made in the leg fold on the lateral side of the scrotum, 1 cm below and
lateral to the insertion of the adductor longus tendon at the medial border of the obturator foramen.
The index finger of the surgeon is then placed between the urethral bulb medially and the proximal
corpus cavernosum laterally, just inside the bulbospongiosus muscle. The helical curved introducer
needle is placed over the skin incision and mild force is used to perforate the subcutaneous tissue and
obturator fascia, maintaining a constant axis of rotation at 45°. The needle is passed towards the tip of
the finger and the tape is then positioned through both obturator fossae. With 2 absorbable sutures the
middle part of the polypropylene tape is then fixed distally onto the bulb and proximally onto the
perineal body. The tape is then pulled at both ends to its final position, and the ends are cut at skin
level. Short-term results of this technique have shown it be effective in 70% of patients.
28
Recently, various adjustable male slings such as ProACT (Uromedica, Plymouth, MN),29 Remeex
(Neomedic, Barcelona, Spain), 30 and Argus (Promedon SA, Cordoba, Argentina)31 have been introduced
in Europe; these slings can be variably tensioned according to patient needs and the degree of recurrent
urinary incontinence.
The ProACT device (see Figure 3) is constructed from silicone elastomer, similar to the materials used in
the AMS 800 AUS. Two ProACT balloons are attached to a reinjectable titanium port with a short length
of tubing and are then implanted periurethrally, on either side of the bladder neck, just proximal to the
remnant external sphincter. The ports are sited subcutaneously under the scrotal dartos fascia to allow
for future percutaneous adjustments of the balloon volume.
A recent paper comparing the last 50 patients to the first 50 patients using ProACT showed a significant
improvement in results.31 Pad usage was reduced significantly in both groups (p < .001). Overall, lategroup patients obtained more consistent outcomes than early-group patients (80% vs. 60% dry). I-QOL
(incontinence quality of life scale) scores improved in both groups although more significantly in the late
group (p = .005).
Operative time and range of complications decreased with evolution of technique. The Argus sling (see
Figure 4) possesses 3 components: a silicone foam cushion (4.2 x 2.6 x 0.9 cm) designed to provide
bulbourethral compression, silicone columns attached to both ends of the pad for fixation against the
abdominal rectus fascia, and silicone washers. All components are radio-opaque to allow sling
repositioning after implantation. The device can be regulated by moving the washers up and down to
create the desired tension. The Argus device is inserted through both a suprapubic and a perineal
incision, in the same fashion as that described by Schaeffer et al. 32
A European multi-center trial enrolling 48 patients found the device to be very effective. At a mean
followup of 7.5 months, 35 (73%) of the patients were dry, and 5 (10%) were improved, although 8
(17%) were incontinent, including 4 (8%) who needed sling adjustment.32 There were 3 (6%) urethral
perforations during surgery that were resolved by re-passing the needle. The sling was removed from 3
men (6%) due to erosion and from 2 (4%) due to infection. This compares favorably to the complication
rate associated with artificial urinary sphincters.
The male Remeex system is composed of a monofilament suburethral sling connected to a suprapubic
mechanical regulator with 2 monofilament traction threads (see Figure 5). The mechanical regulator, or
varitensor, is a subcutaneous permanent implant, placed over the abdominal rectum fascia 2 cm above
the pubis, used to wind and tighten the traction threads. The suburethral sling is also placed in a fashion
similar to that for the Schaeffer sling.
In a recent multi-center European study, 33 51 patients with mild to severe stress urinary incontinence
were treated with the Remeex system. Of these, 44 (86%) patients required a single adjustment of
tension between 1 and 4 months after surgery, while 17 (33%) other patients required more than 1
delayed tension adjustment. Overall, 33 (65%) patients were considered cured, another 10 (20%)
showed improvement, while 8 (16%) were unchanged. The average follow-up time was 32 months. The
mesh was removed in 1 (2%) case due to urethral erosion, and the varitensor in 2 (4%) cases was
removed due to infection. There were 5 (10%) uneventful intraoperative bladder perforations and 3
(6%) mild perineal hematomas reported.
Conclusion
Male stress urinary incontinence may be treated with multiple modalities. Current surgical options for
post-prostatectomy incontinence include bulking agents such as collagen and devices such as the AUS.
Low success rates with bulking agents and high revision rates with the AUS have prompted a resurgence
of interest in fixed urethral compression procedures. The modern male sling is an exciting development
in fixed urethral compression. Patients with mild to moderate SUI may benefit greatly from use of this
technology.
References
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33. Sousa-Escandón A, Cabrera J, Mantovani F, Moretti M, Ioanidis E, Kondelidis N, et al.
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