118 CHAPTER 4 Incontinence
Treatment of sphincter weakness incontinence: pubovaginal slings
Indications
Sling procedures were developed mainly for female stress incontinence associated with poor urethral function (type III or ISD) or when previous surgical procedures have failed. The success of sling procedures, however, has resulted in expanded applications in women with hypermobility. It is essential that urethral and bladder function is evaluated prior to surgical repair.
Types of sling
•Autologous—rectus fascia, fascia lata (from the thigh), vaginal wall slings
•Nonautologous—allograft fascia lata from donated cadaveric tissue
•Synthetic—monofilament “macropore” polypropylene mesh (via transobturator, transabdominal, or transvaginal needles)
Autologous and allograft slings
The tissue strip is inserted via an abdominal incision and tunneled through the endopelvic fascia on one side, behind the proximal urethra and into the anterior vagina, and then guided out the other side. The two ends are sutured to rectus fascia, using the minimal amount of tension needed to prevent urethral movement. Alternative methods of fixation include bone anchoring; however, this is associated with increased risk of osteitis pubis.
Synthetic slings
Synthetic slings have become extremely popular worldwide—these procedures are less invasive, can be inserted under local anesthetic as a day case, and have few complications. The slings are inserted using either suprapubic (TVT™, SPARC™) or transobturator (Monarch™, TVT-O™) needles and tunneled into a mid-urethral location. “Macropore” polypropylene slings have been widely recognized as being more resistant to infectious complications
Cystoscopy is often used to detect bladder perforation during sling placement. Postoperatively, patients may temporarily require ISC until post-void residuals are <100 mL.
Outcomes
Overall, long-term cure rates for slings are 80%, with improvement seen in 90%.1 Complication rates are low but include voiding disorders (urinary retention, de novo bladder overactivity); vaginal, urethral, and bladder erosions; bowel and bladder perforation; and pelvic bleeding.
<?> 1 Abrams P, Cardozo L, Khoury S, et al. (Eds.) (2002) Incontinence, 2nd International Consultation on Incontinence, 2nd ed, Health Publications Ltd, pp. 825–863.
This page intentionally left blank
120 CHAPTER 4 Incontinence
Treatment of sphincter weakness incontinence: the artificial urinary sphincter
The artificial urinary sphincter (AUS; AMS800™) consists of an inflatable cuff placed around the bulbar urethra in men, via either a perineal or high scrotal incision. Good coaptation of the cuff around the proximal corpus spongiosum provides the best outcomes.
Other components include a pressure-regulating balloon placed extraperitoneally, and an activating pump placed in the scrotum. The cuff, when activated, provides a constant pressure to compress the urethra. To void, the pump is squeezed, which transfers all fluid to the reservoir balloon, thereby deflating the cuff. The cuff then automatically refills within 3 minutes. Voiding takes place in the interval taken for the cuff to refill.
In women, a lower abdominal incision (midline or Pfannenstiel) may be used to place a cuff around the bladder.
Indications and patient selection
Indications include incontinence secondary to urethral sphincter deficiency in patients with normal bladder capacity and compliance. In men, it is used almost always for sphincter damage due to prostatectomy (radical prostatectomy for prostate cancer or TURP). In women it can be used for neuropathic sphincter weakness (e.g., spinal cord injury, spina bifida) if the incontinence is not due to bladder overactivity.
If there is combined bladder overactivity and sphincter weakness, treat the bladder first (i.e., trial of anticholinergics)—in some cases this will be enough to achieve continence. If incontinence persists, proceed with AUS at a later date.
Good manual dexterity is required to manipulate the pump. Patients must also have sufficient cognitive function to operate the sphincter by themselves, several times daily.
Patient evaluation
Patients should undergo a careful history and physical exam to evaluate voiding function and severity of incontinence. Although urodynamics and/ or cystoscopy are often used to further identify anatomical abnormalities within the lower urinary tract in complex cases, “garden variety” SUI can often be diagnosed reliably on the basis of careful history and physical alone.
Results
An AUS can function well for many years. Overall long-term success (continued continence, no device malfunction) is 80%. Revision rates are about 20%, usually due to subcuff atrophy.
TREATMENT OF SPHINCTER WEAKNESS INCONTINENCE 121
Complications and long-term outcomes
Recurrent incontinence
This is secondary to urethral atrophy under the cuff (10% over the first 5 years post implantation); mechanical failure; urethral erosion (due to chronic pressure/ischemia from the cuff, often due to urethral catheterization during nonurological procedures without prior cuff deactivation); bladder overactivity or reduced compliance causing reflux; hydronephrosis; and renal failure.
Investigate recurrent incontinence by cystoscopy (to exclude erosion) and urodynamics (to detect high bladder pressures).
Erosion
Erosion is most common at 3–4 months, with 75% occurring in the first year. Patients present with pain and swelling of the scrotum, sudden worsening of incontinence, UI, and bloody discharge. Cuff erosion usually occurs if the AUS is not deactivated during catheterization or instrumen- tation—this dreaded complication results in prompt surgical removal of the entire device.
Use of an indwelling urethral catheter for more than 24 hours should be avoided in men with an AUS to prevent erosion—if long-term urinary diversion is required, consider SP tube placement.
Infection
Primary implant infection rates are 1–3%. With infection or erosion, remove the entire device and wait 3–6 months before reinsertion.
Salvage of an infected AUS may be accomplished via removal of the infected device, followed by copious washout with antiseptic solutions and immediate replacement with a new device