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Artificial Sphincters in Children with Neurogenic Bladders: Long-Term Results
0022-5347 /82/1286-1270$02.00/0 Vol. 128, December Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright© 1982 by The Williams & Wilkins Co.
ARTIFICIAL SPHINCTERS IN CHILDREN WITH NEUROGENIC BLADDERS: LONG-TERM RESULTS RICARDO GONZALEZ
AND
CURTIS A. SHELDON
From the Department of Urologic Surgery, University of Minnesota College of Health Sciences, Minneapolis, Minnesota
ABSTRACT
Inflatable bladder sphincters (models AS 721 and AS 792) were implanted in 10 boys and 5 girls, between 5 and 17 years old, who had neurogenic bladders without residual urine or reflux and with normal renal function. Of the boys 9 are continent with an average followup of 51.5 months, whereas only 1 of the girls is continent. The incidence of mechanical failures is lower with the new AS 792 sphincter (2 of 11 versus 7 of 13 devices), and the 2 erosions occurred in girls whose bladder necks were opened during implantation. The artificial sphincter is useful in boys with neurogenic bladders without residual urine if bladder spasticity is controlled. We use the device in girls only when pharmacological methods and intermittent catheterization have failed. We have been satisfied with the long-term results even if reoperations were needed. Inflatable artificial bladder sphincters have been used since 1972, 1 principally in incontinent adults with isolated sphincter failure and normally innervated bladders. 2 In children incontinence usually results from extensive neurological deficits affecting the sphincter, the sensory and motor functions of the bladder, and the synergy of the detrusor bladder neck sphincter complex. Therefore, the success rates with implantable sphincters have differed widely. 3 - 6 We have implanted 26 artificial sphincters in 15 children with neurovesical dysfunction. The results were satisfactory in 9 boys and l girl. Mechanical failure of the device, causing recurrent incontinence, was the most common complication. PATIENTS AND METHODS
AS 721 and AS 792* inflatable artificial sphincters were used. The AS 721 model, which is no longer available, consisted of an inflatable sphincter, a fluid reservoir, inflating and deflating pumps, and a pressure-regulating valve (part A of figure). 1 The AS 792 model consists of an improved inflatable sphincter, a regulating balloon with a set pressure ranging from 50 to 90 cm. water, a delay-fill resistor that provides automatic slow closure of the sphincter and a deflating mechanism (part B of figure). 7 With the AS 792 model the sphincter remains closed at the pressure determined by the balloon until the patient opens it with the deflating mechanism. Thus, only l manipulation usually is required for each voiding. Criteria for selection for implantation were absence of residual urine, normal renal function and normal upper tracts on urography, absence of vesicoureteral reflux, purposeful use of the arms and hands, and ability to walk unassisted. In addition, the patient or the parents had to be enthusiastic about the procedure and understand fully what would be required. 5 Detrusor hyperreflexia and urinary tract infection were controlled pharmacologically before implantation was considered. Artificial sphincters were implanted in 10 boys and 5 girls between 5 and 17 years old. In all cases the device was placed at the bladder neck. N eurogenic bladder and incontinence resulted from myelomeningocele in 8 patients, spinal cord tumors in 3 and sacral agenesis in 3. In the remaining patient the cause could not be identified. Of the boys 5 had undergone transurethral external sphincterotomies previously because of
large residual urine volumes or detrusor-sphincter dyssynergia and vesicoureteral reflux was corrected successfully in l. In 2 girls extensive V-flap urethroplasties were performed at the time of implantation to facilitate bladder emptying. RESULTS
Boys. In 6 boys AS 721 sphincters were implanted initially. Of these devices l is functioning after 88 months and 5 malfunctioned. In 3 cases a second AS 721 device was implanted, 1 of which is still functioning 44 months later. However, another boy had pressure necrosis of the bladder neck with scrotal edema 9½ months later. The device was removed and no further attempts have been made to establish continence. This child represents the only failure among the boys. During replacement of another malfunctioning AS 721 sphincter calcareous incrustations were found inside the device, leading to discovery of an asymptomatic perforation of the posterior bladder neck. This patient received an AS 792 sphincter 6 months later with satisfactory results. The 2 remaining children with malfunctioning AS 721 devices received AS 792 sphincters and are now continent. In 4 boys AS 792 sphincters were implanted initially. In 2 cases the sphincters malfunctioned 2 and 3 months after implantation but were replaced with the same model with satisfactory results. Of these boys l became incontinent early postoperatively when the delay-fill resistor became obstructed, probably by blood introduced into the sphincter device during implantation. The resistor was replaced with satisfactory results. In l boy, whose AS 792 device had been implanted when he was 7 years old and had functioned well for 3 years, overflow incontinence developed at the onset of puberty. Evaluation suggested obstruction caused by the enlargement of the prostate within the confines of a small sphincter. After replacement with a larger sphincter the boy was continent and without residual urine. All 7 boys with AS 792 sphincters are now continent and no erosions of the bladder neck have been noted, with a maximum followup of 42 months (average 22 months). Girls. We implanted 5 AS 721 and 2 AS 792 sphincters in the 5 girls. Only 1 girl, who has an AS 792 device, is continent after 30 months, although initial stress incontinence necessitated a change to a regulating balloon with a higher pressure. Another girl was continent for 18 months with an AS 721 sphincter before it malfunctioned. During an operation to replace it with an AS 792 device the bladder neck was injured and later erosion necessitated removal of the second device. In another girl the
Accepted for publication March 12, 1982. Read at annual meeting of American Urological Association, Kansas City, Missouri, May 16-20, 1982. * American Medical Systems, Minneapolis, Minnesota. 1270
l27l
~
/
,Fluid Storage Reservoir
Artificial urinary sphincters. A, model AS 721, which is no longer available. B, model AS 792
device had to be removed because bladder spasticity could not be controlled with anticholinergic drugs. This patient was not an appropriate candidate for an artificial sphincter. The remaining 2 girls suffered bladder neck erosion, accompanied in 1 case by retention requiring intermittent catheterization. Both of these girls had undergone V-flap urethroplasties at the time the sphincters were implanted. DISCUSSION
The artificial bladder sphincter, based on a proposal Foley in 1947, 8 has been improved considerably in the last few years, as is evident from our data. In 13 implantations of the AS 721 device 7 malfunctioned and 4 had bladder neck erosion. In comparison, only 2 of the 11 AS 792 devices malfunctioned and 2 erosions occurred in girls whose bladder necks were opened during the implantation. Thus, if the bladder neck appears poorly vascularized the AS 792 device should not be activated during implantation. 9 Later, after a fibrous capsule has formed around it and the bladder neck appears to be able to tolerate pressure, the parts of the device can be connected in a simple operation. Of course, longer followup is necessary before a definitive statement can be made on the risk of erosion with the AS 792 device. There were no infections of the which occur almost exclusively in patients with chronic tract infections and require removal of the device. 10 The only apparent drawback of the new automatic is its set re-inflation time, which can cause problems for patients with a poor urinaxy flow rate. These patients are taught that they will have to deflate the sphincter more than once per micturition. Also, the patients require careful followup, particularly when they approach puberty, since a growing prostate gland within a nonexpandable cuff caused bladder outlet obstruction in l boy. It also is clear from our results that artificial sphincters are not appropriate for all patients with neurogenic bladders. The results in boys are encouraging, with 9 of 10 continent. We prefer sphincter implantation to intermittent catheterization if the patient can empty the bladder completely because the device helps keep the urine sterile and improves the social adjustment. We perform external sphincterotomy 6 to 12 weeks before sphincter implantation if there is direct (cystometrographic and electromyelographic) or indirect (reflux or trabeculation) evidence of dyssynergia, even if there is no residual
urine. Our experience with these sphincters in girls has been less encouraging, and we implant the device only after all pharmacological and catheterization programs have failed. The lower complication rate of the AS 792 device makes artificial sphincters even more appealing than they were a few years ago, and their use in children need not be limited to patients with neurogenic bladders. The devices should be considered for incontinent patients after undiversion, reconstruction of exstrophied bladder or transurethral resection of posterior urethral valves. The 9 continent boys in this series have been followed for an average of 51.5 months (range 6 to 88 months), including 6 patients who have been followed for >40 months since the initial implantation. Although many have required reoperations for revisions or change of sphincters, all boys are satisfied with the results. REFERENCES 1. Scott, F. B., Bradley, W. E. and Timm, G. W.: Treatment of urinary
2.
3. 4. 5. 6.
7.
8.
9.
10.
incontinence by an implantable prosthetic urinary sphincter. J. Uro!., 112: 75, 1974. Furlow, W. L.: The uuµum,,rn.,e artificiai genitourinary sphincter in the management total urinary incontinence. Jl/fayo Clin. Proc., 51: 341, 1976. Diokno, A. C. and Taub, M. E.: =Apc,"v'"~c with the artificial urinary spJ~mctt,r at I\/Hchigan. 116: 496, 1976. Montague, K. and Stewart, B. H.: Experience with a urinary sphincter prosthesis. & Obst., 145: 693, 1977. Gonzalez, R. and DeWo!f, · The artificial bladder sphincter AS- 721 for the treatment of incontinence in patients with neurogenic bladder. J. Urol., 121: 71, 1979. Hald, T., Bystrom, J. and Alfthan, 0.: Treatment of urinary incontinence by the Scott-Bradley-Timm artificial sphincter. Urol. Res., 3: 133, 1975. Burton, J. H., Mikulich, M.A., Timm, G. W., Scott, F. B., Attia, S. A. and Bradley, W. E.: Development of urethral occlusive tech-· niques for restoration of urinary continence. Med. Instrum., 11: 217, 1977. Foley, F. E.: An artificial sphincter: a new device and operation for control of enuresis and urinary incontinence. J. Urol., 58: 250, 1947. Furlow, W. L.: Implantation of a new semiautomatic artificial genitourinary sphincter: experience with primary activation and deactivation in 47 patients. J. Urol., 126: 741, 1981. Pagani, J. J., Cochran, S. T., Bruskewitz, R., Raz, S. and Barbaric, Z. L.: Radiographic evaluation of an artificial urinary sphincter (AMS 792). Radiology, 134: 361, 1980.
THE JOURNAL OF UROLOGY
Copyright© 1982 by The Williams & Wilkins Co.
ARTIFICIAL SPHINCTERS IN CHILDREN WITH NEUROGENIC BLADDERS: LONG-TERM RESULTS RICARDO GONZALEZ
AND
CURTIS A. SHELDON
From the Department of Urologic Surgery, University of Minnesota College of Health Sciences, Minneapolis, Minnesota
ABSTRACT
Inflatable bladder sphincters (models AS 721 and AS 792) were implanted in 10 boys and 5 girls, between 5 and 17 years old, who had neurogenic bladders without residual urine or reflux and with normal renal function. Of the boys 9 are continent with an average followup of 51.5 months, whereas only 1 of the girls is continent. The incidence of mechanical failures is lower with the new AS 792 sphincter (2 of 11 versus 7 of 13 devices), and the 2 erosions occurred in girls whose bladder necks were opened during implantation. The artificial sphincter is useful in boys with neurogenic bladders without residual urine if bladder spasticity is controlled. We use the device in girls only when pharmacological methods and intermittent catheterization have failed. We have been satisfied with the long-term results even if reoperations were needed. Inflatable artificial bladder sphincters have been used since 1972, 1 principally in incontinent adults with isolated sphincter failure and normally innervated bladders. 2 In children incontinence usually results from extensive neurological deficits affecting the sphincter, the sensory and motor functions of the bladder, and the synergy of the detrusor bladder neck sphincter complex. Therefore, the success rates with implantable sphincters have differed widely. 3 - 6 We have implanted 26 artificial sphincters in 15 children with neurovesical dysfunction. The results were satisfactory in 9 boys and l girl. Mechanical failure of the device, causing recurrent incontinence, was the most common complication. PATIENTS AND METHODS
AS 721 and AS 792* inflatable artificial sphincters were used. The AS 721 model, which is no longer available, consisted of an inflatable sphincter, a fluid reservoir, inflating and deflating pumps, and a pressure-regulating valve (part A of figure). 1 The AS 792 model consists of an improved inflatable sphincter, a regulating balloon with a set pressure ranging from 50 to 90 cm. water, a delay-fill resistor that provides automatic slow closure of the sphincter and a deflating mechanism (part B of figure). 7 With the AS 792 model the sphincter remains closed at the pressure determined by the balloon until the patient opens it with the deflating mechanism. Thus, only l manipulation usually is required for each voiding. Criteria for selection for implantation were absence of residual urine, normal renal function and normal upper tracts on urography, absence of vesicoureteral reflux, purposeful use of the arms and hands, and ability to walk unassisted. In addition, the patient or the parents had to be enthusiastic about the procedure and understand fully what would be required. 5 Detrusor hyperreflexia and urinary tract infection were controlled pharmacologically before implantation was considered. Artificial sphincters were implanted in 10 boys and 5 girls between 5 and 17 years old. In all cases the device was placed at the bladder neck. N eurogenic bladder and incontinence resulted from myelomeningocele in 8 patients, spinal cord tumors in 3 and sacral agenesis in 3. In the remaining patient the cause could not be identified. Of the boys 5 had undergone transurethral external sphincterotomies previously because of
large residual urine volumes or detrusor-sphincter dyssynergia and vesicoureteral reflux was corrected successfully in l. In 2 girls extensive V-flap urethroplasties were performed at the time of implantation to facilitate bladder emptying. RESULTS
Boys. In 6 boys AS 721 sphincters were implanted initially. Of these devices l is functioning after 88 months and 5 malfunctioned. In 3 cases a second AS 721 device was implanted, 1 of which is still functioning 44 months later. However, another boy had pressure necrosis of the bladder neck with scrotal edema 9½ months later. The device was removed and no further attempts have been made to establish continence. This child represents the only failure among the boys. During replacement of another malfunctioning AS 721 sphincter calcareous incrustations were found inside the device, leading to discovery of an asymptomatic perforation of the posterior bladder neck. This patient received an AS 792 sphincter 6 months later with satisfactory results. The 2 remaining children with malfunctioning AS 721 devices received AS 792 sphincters and are now continent. In 4 boys AS 792 sphincters were implanted initially. In 2 cases the sphincters malfunctioned 2 and 3 months after implantation but were replaced with the same model with satisfactory results. Of these boys l became incontinent early postoperatively when the delay-fill resistor became obstructed, probably by blood introduced into the sphincter device during implantation. The resistor was replaced with satisfactory results. In l boy, whose AS 792 device had been implanted when he was 7 years old and had functioned well for 3 years, overflow incontinence developed at the onset of puberty. Evaluation suggested obstruction caused by the enlargement of the prostate within the confines of a small sphincter. After replacement with a larger sphincter the boy was continent and without residual urine. All 7 boys with AS 792 sphincters are now continent and no erosions of the bladder neck have been noted, with a maximum followup of 42 months (average 22 months). Girls. We implanted 5 AS 721 and 2 AS 792 sphincters in the 5 girls. Only 1 girl, who has an AS 792 device, is continent after 30 months, although initial stress incontinence necessitated a change to a regulating balloon with a higher pressure. Another girl was continent for 18 months with an AS 721 sphincter before it malfunctioned. During an operation to replace it with an AS 792 device the bladder neck was injured and later erosion necessitated removal of the second device. In another girl the
Accepted for publication March 12, 1982. Read at annual meeting of American Urological Association, Kansas City, Missouri, May 16-20, 1982. * American Medical Systems, Minneapolis, Minnesota. 1270
l27l
~
/
,Fluid Storage Reservoir
Artificial urinary sphincters. A, model AS 721, which is no longer available. B, model AS 792
device had to be removed because bladder spasticity could not be controlled with anticholinergic drugs. This patient was not an appropriate candidate for an artificial sphincter. The remaining 2 girls suffered bladder neck erosion, accompanied in 1 case by retention requiring intermittent catheterization. Both of these girls had undergone V-flap urethroplasties at the time the sphincters were implanted. DISCUSSION
The artificial bladder sphincter, based on a proposal Foley in 1947, 8 has been improved considerably in the last few years, as is evident from our data. In 13 implantations of the AS 721 device 7 malfunctioned and 4 had bladder neck erosion. In comparison, only 2 of the 11 AS 792 devices malfunctioned and 2 erosions occurred in girls whose bladder necks were opened during the implantation. Thus, if the bladder neck appears poorly vascularized the AS 792 device should not be activated during implantation. 9 Later, after a fibrous capsule has formed around it and the bladder neck appears to be able to tolerate pressure, the parts of the device can be connected in a simple operation. Of course, longer followup is necessary before a definitive statement can be made on the risk of erosion with the AS 792 device. There were no infections of the which occur almost exclusively in patients with chronic tract infections and require removal of the device. 10 The only apparent drawback of the new automatic is its set re-inflation time, which can cause problems for patients with a poor urinaxy flow rate. These patients are taught that they will have to deflate the sphincter more than once per micturition. Also, the patients require careful followup, particularly when they approach puberty, since a growing prostate gland within a nonexpandable cuff caused bladder outlet obstruction in l boy. It also is clear from our results that artificial sphincters are not appropriate for all patients with neurogenic bladders. The results in boys are encouraging, with 9 of 10 continent. We prefer sphincter implantation to intermittent catheterization if the patient can empty the bladder completely because the device helps keep the urine sterile and improves the social adjustment. We perform external sphincterotomy 6 to 12 weeks before sphincter implantation if there is direct (cystometrographic and electromyelographic) or indirect (reflux or trabeculation) evidence of dyssynergia, even if there is no residual
urine. Our experience with these sphincters in girls has been less encouraging, and we implant the device only after all pharmacological and catheterization programs have failed. The lower complication rate of the AS 792 device makes artificial sphincters even more appealing than they were a few years ago, and their use in children need not be limited to patients with neurogenic bladders. The devices should be considered for incontinent patients after undiversion, reconstruction of exstrophied bladder or transurethral resection of posterior urethral valves. The 9 continent boys in this series have been followed for an average of 51.5 months (range 6 to 88 months), including 6 patients who have been followed for >40 months since the initial implantation. Although many have required reoperations for revisions or change of sphincters, all boys are satisfied with the results. REFERENCES 1. Scott, F. B., Bradley, W. E. and Timm, G. W.: Treatment of urinary
2.
3. 4. 5. 6.
7.
8.
9.
10.
incontinence by an implantable prosthetic urinary sphincter. J. Uro!., 112: 75, 1974. Furlow, W. L.: The uuµum,,rn.,e artificiai genitourinary sphincter in the management total urinary incontinence. Jl/fayo Clin. Proc., 51: 341, 1976. Diokno, A. C. and Taub, M. E.: =Apc,"v'"~c with the artificial urinary spJ~mctt,r at I\/Hchigan. 116: 496, 1976. Montague, K. and Stewart, B. H.: Experience with a urinary sphincter prosthesis. & Obst., 145: 693, 1977. Gonzalez, R. and DeWo!f, · The artificial bladder sphincter AS- 721 for the treatment of incontinence in patients with neurogenic bladder. J. Urol., 121: 71, 1979. Hald, T., Bystrom, J. and Alfthan, 0.: Treatment of urinary incontinence by the Scott-Bradley-Timm artificial sphincter. Urol. Res., 3: 133, 1975. Burton, J. H., Mikulich, M.A., Timm, G. W., Scott, F. B., Attia, S. A. and Bradley, W. E.: Development of urethral occlusive tech-· niques for restoration of urinary continence. Med. Instrum., 11: 217, 1977. Foley, F. E.: An artificial sphincter: a new device and operation for control of enuresis and urinary incontinence. J. Urol., 58: 250, 1947. Furlow, W. L.: Implantation of a new semiautomatic artificial genitourinary sphincter: experience with primary activation and deactivation in 47 patients. J. Urol., 126: 741, 1981. Pagani, J. J., Cochran, S. T., Bruskewitz, R., Raz, S. and Barbaric, Z. L.: Radiographic evaluation of an artificial urinary sphincter (AMS 792). Radiology, 134: 361, 1980.