Use of the AS792 artificial sphincter following urinary undiversion

Neurogenic bladder - concepts and treatment recommendations

Introduction:

Bladder and urinary sphincter malfunctioning that results from some change in the central and/or peripheral nervous system is defined as neurogenic bladder. The urinary tract symptoms that can be related to its filling, emptying, or both have a significant impact on the quality of life of individuals. The present review was based on the document prepared for the public health system in Brazil as a treatment guidelines proposal.

Material and Methods:

Survey questions were structured as per PICO (Population, Intervention, Control, and Outcome). Search strategies were defined and performed in the MEDLINE/Pubmed, Embase, Epistemonikos and Google Scholar databases. The selection of articles followed the evidence hierarchy concept; evidence body was identified, and the quantitative study data were extracted. The quality of evidence and grade of recommendation were qualitatively assessed according to GRADE (Grading of Recommendations, Assessment, Development and Evaluations).

Results:

A total of 2.707 articles were identified, with 49 of them being selected to compose the basis for this review. Neurogenic bladder treatments were classified according to their focus on filling or emptying symptoms and sub- classified in pharmacological and surgical treatments.

Conclusion:

Treatment guidelines are important tools for the public health system to promote the best practice when treating neurogenic bladder patients.

Uneven pressure application by the artificial urinary sphincter: an explanation for tissue ischaemia?

OBJECTIVE

To determine, in an in vitro study, the pressure inside the AMS 800 (American Medical Systems, USA) sphincter placed around porcine intestine and to correlate this with the pressure retention for liquids, in an attempt to explain the increased sensitivity of bowel to ischaemic injury when the artificial urinary sphincter is used around bowel neo-urethral segments.

MATERIALS AND METHODS

Segments of porcine intestine were placed in a specially designed mechanical jig and an AMS 800 sphincter placed around the segment. The device was inflated by injecting water and the cuff pressure measured. Water was infused into the bowel and the pressure at which leakage occurred through the sphincter recorded. At each inflation pressure, a catheter-tipped microtransducer was used to measure the pressure inside the cuff-fold. It was then placed in the centre of the cuff lumen, rotated by 360 degrees and the pressure continuously recorded.

RESULTS

The cuff occluded the lumen by creating a 'triple-cushion' effect. The fluid retention pressure was 49% of the cuff pressure. There were directional differences in the pressure measured inside the bowel lumen. The pressure was also disproportionately higher inside the cuff folds than in the centre of the sphincter, and increased rapidly with inflation of the cuff.

CONCLUSION

The thin wall of the bowel may 'crenate' inside the high-pressure areas in the cuff folds and this may explain the increased sensitivity of bowel to ischaemic injury in such cases.

Combined use of enterocystoplasty and a new type of artificial sphincter in the treatment of urinary incontinence

PURPOSE

We report the results of the combination of enterocystoplasty and a periurethral expander, a simplified type of artificial sphincter, in the treatment of urinary incontinence.

MATERIALS AND METHODS

The new 1-piece device has an adjustable cuff connected to a port positioned at the subcutaneous space in the abdomen. The cuff is adjusted to the bladder neck and the pins are fixed according to the diameter of the urethra. The port is punctured percutaneously and saline is injected until continence is achieved. Eight boys and 3 girls underwent nonsecretory sigmoid cystoplasty and placement of the device at a single operation. Nine patients had neurogenic bladder and in 2 exstrophy reconstruction had failed. Followup ranged from 4 to 26 months.

RESULTS

All patients were continent with improved bladder compliance 6 to 8 weeks after the operation, when the device was activated. In 1 case the device was extracted after 2 months due to frequent episodes of hematuria and edema at the port site. Two patients had erosion of the skin at the port site. Urodynamics were repeated at the time of activation. Maximal urethral closing pressure increased from 16.27 to 157.44%. Two patients needed a second injection to achieve continence. The patients with exstrophy void spontaneously and those with neurogenic bladder are on clean intermittent catheterization.

CONCLUSIONS

Although more followup is needed, the combination of these procedures seems to offer a new option for the treatment of urinary incontinence in children.

Urinary undiversion after implantation of an alloplastic urethral sling for male continence

A man in whom urinary diversion (colon conduit) was performed after 2 unsuccessful implantations of artificial urethral sphincters for treatment of iatrogenic incontinence became continent again after implantation of an alloplastic sling. Three months later the patient underwent urinary undiversion with augmentation cystoplasty. After 3 years ureteroneocystostomy was necessary due to distal ureteral stenoses. At 7-year followup the patient is continent. He has good bladder capacity, bladder emptying and a normal upper urinary tract.

Urinary undiversion in adults with myelodysplasia: long-term followup

A total of 14 women and 6 men 19 to 39 years old (mean age 27 years) with myelodysplasia underwent undiversion 8 to 29 years (mean 16) after ileal conduit diversion. The main reasons for diversion were incontinence in 17 patients and failed ureteral reimplants in 3, and those for undiversion were a desire for an improved quality of life in 16, increasing hydronephrosis in 4 and stomal problems in 3. Preoperative assessment included upper and lower tract imaging, and video urodynamics. Operations on the ureters included reimplantation into an intussuscepted nipple valve in 8 patients, tunneled reimplants into a sigmoid augmentation in 3 and the ureters joined to either the bladder or lower ureter without interposing bowel in 9. All reimplantations were done with nonrefluxing techniques. A total of 18 patients underwent bladder augmentation and 2 women in whom cystectomy was performed for pyocystis underwent substitutions. Simultaneous continence procedures in 18 patients included trigonal tubularization in 2, artificial sphincter implantation in 2, a bladder neck sling in 5 or bladder neck tapering and a sling in 9. The patients were followed for a mean of 69 months (range 21 to 133). Eight patients required reintervention within 1 year for problems, such as anastomotic leak in 1, bladder neck obstruction in 1, incontinence in 1, artificial urinary sphincter revisions in 1 and bladder stones in 1. One patient had a recurrent renal calculus 10 years after undiversion. All patients experienced either persistence of normal upper tract appearance or improvement and/or stabilization of hydronephrosis. Mean bladder capacity was 77 cc preoperatively and 480 cc postoperatively, while mean pressure at capacity decreased from 50 to 14 cm. water with detubularized augmentation. Of the patients 17 are completely dry, 2 wear 1 pad per day and 1 has enuresis. All but 1 patient who voids with straining are on intermittent self-catheterization. All patients, on followup interviews, reported an improved quality of life without a stoma. We conclude that undiversion provides an improved quality of life and an acceptable morbidity rate. The choice of operation depends on the anatomy of the patient. We prefer a nonprosthetic type of incontinence procedure when intermittent self-catheterization is to be done. No long-term morbidity has yet been noted.

Lower urinary tract reconstruction using stomach and the artificial sphincter

We implanted the artificial urinary sphincter at gastrocystoplasty in 13 male and 5 female patients. The diagnoses were classical bladder exstrophy (8 patients), myelodysplasia (8), cloacal exstrophy (1) and bilateral ectopic ureters (1). Mean patient age was 14.3 years (range 7 to 32.5). Six patients (5 with bladder exstrophy and 1 with clocal exstrophy) had failed bladder neck continence procedures, 3 myelodysplastic patients had failed artificial urinary sphincter placement, and 1 exstrophy patient had failed a Young-Dees bladder neck repair and artificial urinary sphincter placement. The sphincter cuff was placed around the reconstructed bladder neck in these patients, while in the remainder the artificial urinary sphincter was placed around the intact bladder neck. Mean followup was 20.3 months (range 1 to 5). Of the patients 16 (88%) are continent day and night, while 2 are wet. A total of 11 patients (61%) use Valsalva's maneuver alone for voiding and the remainder use Valsalva's maneuver and/or clean intermittent catheterization for bladder evacuation. Complications related to the artificial urinary sphincter were recurrent pump erosion requiring conversion to a Mitrofanoff continent stoma in 1 patient, and mechanical dysfunction requiring pump cuff and reservoir replacement in 3. There were no complications due to infection. Our report demonstrates that the combination of augmentation gastrocystoplasty and an artificial urinary sphincter leads to urinary continence and can allow for spontaneous urination. The rate of infectious complications is not increased when the 2 procedures are combined simultaneously.

Artificial urinary sphincters around intestinal segments--are they safe?

Artificial urinary sphincters (AUS) were implanted around intestinal segments to achieve urinary continence in 8 patients and faecal continence in 1. In 6 patients the cuff was placed around the lower end of the cystoplasty following bladder neck (5) or urethral (1) erosion. Four are completely dry, 1 on self-intermittent catheterisation (SIC). One has mild stress incontinence. In 1 patient the cuff eroded at 8 months. Two patients had cuffs implanted parastomally to create continent diversion. One is satisfactory on SIC and the other had her AUS explanted because of life-threatening metabolic acidosis. The rectal cuff was explanted because of faecal impaction above the cuff. As an absolute last resort, placing an AUS round a cystoplasty appears little more hazardous than round bladder neck. The use of the AUS for continent diversion has not been pursued because of reliable techniques of non-prosthetic continent diversion. The current model of the AUS is unsuitable for the treatment of faecal incontinence.

Success of the artificial urinary sphincter after failed surgery for incontinence

We implanted the artificial urinary sphincter in 15 incontinent patients for whom multiple urethral and bladder neck operations, including sphincter placement, had been unsuccessful. The 5 male and 10 female patients ranged from 3 to 26 years old (mean age 11 years). The etiology of incontinence was neurogenic bladder in 10 patients, epispadias in 2, exstrophy in 1, ectopic ureters in 1 and traumatic urethral disruption in 1. Of the 15 patients 13 required augmentation enterocystoplasty and clean intermittent catheterization. The initial anti-incontinence procedures were Young-Dees-Leadbetter bladder neck reconstruction in 10 patients, artificial urinary sphincter placement in 4 and bladder neck suspension in 1. Causes of failure of the primary treatment were erosion (artificial urinary sphincter), and incontinence and/or difficult catheterization (Young-Dees-Leadbetter). Followup from the last salvage operation averaged 21 months (range 6 to 37 months). A total of 58 operations was performed. Among the 4 patients in whom the artificial urinary sphincter eroded the bladder neck repeated attempts to place the cuff at the same site were unsuccessful and erosion occurred in all 4 within 1 year. Sphincter placement was more successful among the 11 patients who initially underwent Young-Dees-Leadbetter bladder neck reconstruction or bladder neck suspension; acceptable continence was attained in 8 patients (73%). We conclude that placement of the sphincter cuff around a previously eroded bladder neck probably will result in erosion. Sphincter implantation should be attempted in patients in whom bladder neck reconstruction has failed. Persistence in the treatment of these patients is essential because multiple operations often are necessary to achieve continence.

The evolution of artificial sphincter cuff in growing animals

An animal model was developed to simulate the effect of implantation of artificial sphincter cuff on the urethra in children. The study was conducted on 28 pigs, 15 castrated males, four uncastrated males and nine females, divided into four groups: control unoperated, and three operated groups. Group I contained young piglets (castrated males, uncastrated males and females), group II contained adult animals and group III contained sham operated animals. An AS 800 belt occlusion cuff was implanted in the deflated state distal to the bladder neck around the urethra in the young and adult groups, while no sphincter was implanted in the sham group. Neither primary nor secondary activation was done. The pigs were followed for a period of six to eight weeks and then sacrificed. The morphological and histological observations on the effects of the artificial sphincter cuff on the underlying urethral tissue showed significant transmural atrophy of the urethral and prostatic segment underlying the cuff in the young growing castrated and uncastrated male group with mild changes in the young female group. Bladder rupture occurred in three uncastrated males. There were no changes encountered in the adult or sham operated groups. Variable degrees of upper tract changes and renal deterioration were seen in the young group. These changes occurred mainly in the male piglets while a lesser degree occurred in the female piglets. No changes were demonstrated in the adult and sham groups. This study suggests the possibility of similar changes occurring in young male children who have undergone artificial sphincter implantation.

Surgical treatment of the incontinent female patient with myelomeningocele

Surgical therapy was required for 42 incontinent female patients with myelomeningocele who had urodynamically documented high pressure bladders. Conservative treatment consisting of cholinolytic and alpha-adrenergic agents, and intermittent self-catheterization had failed. The surgical approach consisted of perivesical denervation (for hyperreflexia), Burch bladder neck suspension, enlargement cystoplasty and ureteral reimplantation when required. Among 33 patients (79 per cent) there was no incontinence on intermittent self-catheterization and 6 (14 per cent) had improvement with rare urgency or stress incontinence. In 3 patients (7 per cent) sphincteric incompetence required a transvaginal sling procedure.

The artificial urinary sphincter

Urinary incontinence has many etiologies and a similarly varied and wide-ranging spectrum of therapeutic alternatives. The AMS artificial sphincter represents one of these options that has a distinct, albeit limited, place in certain patients. The authors outline the mechanical details of these devices and present their own clinical experience in a large pediatric population.

Urinary undiversion and implantation of the artificial urinary sphincter in a 73-year-old man

We report a case of successful urinary undiversion and implantation of an artificial urinary sphincter in a 73-year-old man, who had undergone ileal loop urinary diversion elsewhere for treatment of urinary incontinence secondary to transurethral prostatectomy. The rationale for our decision to perform undiversion is presented. Evaluation of patient history and physical examination are necessary, as well as delineation of the anatomy and function of the upper and lower tracts by laboratory, radiological and urodynamic examinations. Each undiversion case is unique. Treatment must be individualized and should be initiated only after meticulous weighing of the advantages and disadvantages of the different therapeutic alternatives. A complete explanation to the patient is important. Highly satisfying results can be expected in appropriately selected cases.

The Mainz pouch (mixed augmentation ileum and cecum) for bladder augmentation and continent diversion

The surgical technique for construction of the Mainz (mixed augmentation ileum and cecum) ileocecal pouch for bladder augmentation or continent urinary diversion focuses on 3 functional features: creation of a low pressure reservoir of adequate capacity from cecum and 2 ileal loops, which are split open longitudinally, antirefluxing ureteral implantation into cecum or ascending colon, achieved by a standard submucosal tunnel technique, and in cases of bladder augmentation continence depends on competence of the bladder neck and urethral closure mechanisms, while in urinary diversion continent closure of the pouch is achieved by isoperistaltic ileoileal intussusception or implantation of an alloplastic stomal prosthesis. Of 11 patients with Mainz pouch bladder augmentation (5 of which were undiversions) 10 are completely dry day and night with normal intervals of bladder evacuation. Two patients with myelomeningocele are on intermittent catheterization for bladder evacuation, while the remainder void spontaneously without significant residual urine. Of 12 patients with Mainz pouch urinary diversion 6 have an ileoileal intussusception valve and are completely continent, as are 3 of 4 with an alloplastic stomal prosthesis. Two patients still are awaiting implantation of a sphinteric prosthesis.

Le bag: total replacement of the bladder using an ileocolonic pouch

Creation of an ileocolonic pouch for total bladder replacement is described in 4 patients, resulting in a highly compliant, low pressure bladder. Previous experience with bowel segments for bladder augmentation and replacement have been plagued by unpredictable bowel contractions with urinary incontinence as well as potential for renal damage. A reliable method to achieve a highly compliant, low pressure system requires disruption of directional bowel peristalsis, which this technique has succeeded in achieving. The operative technique, bowel dynamics, renal status and clinical results are described. The ileocolonic pouch offers a low pressure reservoir for total replacement of the bladder in selected patients.

Reconstruction of the lower urinary tract: observations on bowel dynamics and the artificial urinary sphincter

In 14 patients the lower urinary tract was reconstructed using bowel and the artificial urinary sphincter. Of these patients 11 underwent augmentation cystoplasty. The ileocecal segment was used in 4, cecum in 4 and ileum in 3. Total reconstruction of the lower urinary tract was done using the sigmoid colon in 2 patients and an ileocecocolonic segment in 1. Significant bowel contractions were seen in all segments of the large bowel, including the ileocecal segment, which resulted in urinary incontinence in 3 patients with the artificial urinary sphincter and reflux in 3. The ileal cup-patch technique consistently produced low bladder pressures with excellent compliance and an adequate volume. Because of the unpredictable bowel contractions observed in the ileocecal, sigmoid and cecal segments we recommend that augmentation cystoplasty be performed using the cup-patch technique. This procedure will ensure the virtual absence of bowel contractions, and is associated with excellent compliance and capacity.

Total reconstruction of the lower urinary tract using bowel and the artificial urinary sphincter

We report 3 cases in which the lower urinary tract was reconstructed using bowel. In each instance the cuff was placed around the bowel to provide a continence mechanism. The 2 patients in whom the sigmoid colon was used have sporadic diurnal incontinence with nocturnal enuresis. Urodynamic evaluation has shown that this is secondary to high pressures generated within the closed sigmoid loop. The ileocecocolonic segment is preferable for reconstruction of the lower urinary tract, since the pressure developed within the bowel is significantly lower. The use of the artificial urinary sphincter around the bowel extended the versatility of the device.

The artificial urinary sphincter in children

One hundred and thirty-two children underwent implantation of the AS792 artificial urinary sphincter over the past 5 years: 90% had an excellent result following the implantation. Thirty-one patients (24%) required further surgery to correct a malfunction of the device. The device was removed in 5.3% of the patients and the incidence of infection was 3.8%. The artificial urinary sphincter has been shown to be a reliable means of achieving urinary incontinence in children. With attention to patient selection and meticulous surgical technique, a high success rate can be expected.

Use of the artificial urinary sphincter in spinal cord injury patients

A total of 49 patients with neuropathic bladder dysfunction and urinary incontinence underwent implantation of the AS791/792 artificial urinary sphincter. Preoperative urodynamic evaluation allowed the bladder response to be categorized as hyperreflexia, areflexia and low compliance. The over-all success rate in obtaining total urinary continence in these patients was 70 per cent, although the type of bladder present did influence the degree of success. Although urodynamic evaluation is an essential prerequisite for sphincter implantation there were no clear-cut data that allowed an accurate prediction of the postoperative result. The only absolute contraindication to implantation of the artificial urinary sphincter is significant bladder fibrosis. Owing to the success in obtaining total urinary continence in this complicated group of patients, we believe that the artificial urinary sphincter should be considered in carefully selected patients with neuropathic bladder dysfunction secondary to spinal cord injury.