LONG-TERM OUTCOME OF ARTIFICIAL URINARY SPHINCTERS
2 problems are intrinsic to the mechanical design of the device. Furthermore, device expectancy is limited because in most cases the system leaks, usually from a perforation within a crease in the cuff. Manufacture of the cuff using a curved rather than a flat template may decrease this problem. Results in women are not as good as in men, possibly due to difficult insertion of the cuff around the bladder neck. A different cuff design for women may be beneficial. In addition, the problem of early infection or erosion may be decreased by impregnating the device with antibiotics during manufacture. Moreover, the artificial urinary sphincter remains expensive, which undoubtedly affects how it is used. To achieve better results than this prosthesis any novel artificial sphincter must consider these points.
14. 15. 16. 17. 18. 19.
We noted a satisfactory outcome in 84% of our patients in whom an artificial urinary sphincter was inserted more than 10 years ago. The outcome of post-prostatectomy incontinence was particularly good with few complications or revisions. The long-term outcome in neuropathy was not as good but it was satisfactory. Although there is a significantly higher risk of revision due to infection and erosion in this complex group of patients, improved quality of life resulting from a functioning artificial urinary sphincter makes this risk worthwhile. In female patients with refractory stress incontinence the risk of failure was higher, particularly after previous surgery to the bladder neck. This finding emphasizes the importance of avoiding multiple operations before resorting to artificial urinary sphincter implantation in this group. Ellen Olds and Maria Nightingale assisted with data collection and patient care. REFERENCES
1. Scott, F. B., Bradley, W. E. and Timm, G. W.: Treatment of urinary incontinence by an implantable prosthetic sphincter. Urology, 1: 252, 1973 2. 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 3. Gundian, J. C., Barrett, D. M. and Parulkar, B. G.: Mayo Clinic experience with use of the AMS800 artificial urinary sphincter for urinary incontinence following radical prostatectomy. J Urol, 142: 1459, 1989 4. Webster, G. D., Perez, L. M., Khoury, J. M. et al: Management of type III stress urinary incontinence using artificial urinary sphincter. Urology, 39: 499, 1992 5. Stephenson, T. P. and Mundy, A. R.: Treatment of the neuropathic bladder by enterocystoplasty and selective sphincterotomy or sphincter ablation and replacement. Br J Urol, 57: 27, 1985 6. Light, J. K. and Scott, F. B.: The artificial urinary sphincter in children. Br J Urol, 56: 54, 1984 7. Light, J. K. and Scott, F. B.: Total reconstruction of the lower urinary tract using bowel and the artificial urinary sphincter. J Urol, 131: 953, 1984 8. Singh, G. and Thomas, D. G.: Artificial urinary sphincter in patients with neurogenic bladder dysfunction. Br J Urol, 77: 252, 1996 9. Singh, G. and Thomas, D. G.: Artificial urinary sphincter for post-prostatectomy incontinence. Br J Urol, 77: 248, 1996 10. Hajivassiliou, C. A.: A review of the complications and results of implantation of the AMS artificial urinary sphincter. Eur Urol, 35: 36, 1999 11. Levesque, P. E., Bauer, S. B., Atala, A. et al: Ten-year experience with the artificial urinary sphincter in children. J Urol, 156: 625, 1996 12. Kryger, J. V., Spencer Barthold, J., Fleming, P. et al: The outcome of artificial urinary sphincter placement after a mean 15-year follow-up in a paediatric population. BJU Int, 83: 1026, 1999 13. Fulford, S. C., Sutton, C., Bales, G. et al: The fate of the ‘modern’
artificial urinary sphincter with a follow-up of more than 10 years. Br J Urol, 79: 713, 1997 Mundy, A.: Urodynamic and Reconstructive Surgery of the Lower Urinary Tract. London: Churchill Livingston, pp. 64 – 73, 98 –102, 159 –160, 1993 Nurse, D. E. and Mundy, A. R.: One hundred artificial sphincters. Br J Urol, 61: 318, 1988 Elliott, D. S. and Barrett, D. M.: Mayo Clinic long-term analysis of the functional durability of the AMS 800 artificial urinary sphincter: a review of 323 cases. J Urol, 159: 1206, 1998 Chatelain, C. and Richard, F.: Artificial urinary sphincter. Bull Acad Natl Med, 179: 599, 1995 Duncan, H. J., Nurse, D. E. and Mundy, A. R.: Role of the artificial urinary sphincter in the treatment of stress incontinence in women. Br J Urol, 69: 141, 1992 Duncan, H. J., McInerney, P. D. and Mundy, A. R.: Late erosion. A new complication of artificial urinary sphincters. Br J Urol, 72: 597, 1993 Pe´rez, L. M. and Webster, G. D.: Successful outcome of artificial urinary sphincters in men with post-prostatectomy urinary incontinence despite adverse implantation features. J Urol, 148: 1166, 1992 Mundy, A. R.: Artificial sphincters. Br J Urol, 67: 225, 1990 EDITORIAL COMMENTS
Any physician performing artificial urinary sphincter surgery should carefully read this article. The results and discussion are packed with useful information from a well-known center for last resort incontinence. Author experiences and comments are illuminating because to my knowledge no other published series includes such a variety of patient indications for the urinary sphincter under observation for such a long period. In this study when continence was not restored by bulbar implantation of the sphincter in men after prostatectomy, the authors resorted to increasing balloon pressure or placing the cuff in a bladder neck location. Many in this country have been disappointed with increasing balloon pressure and instead would have added another bulbar cuff in tandem with the original.1 The authors also stated that a sphincter should be the next step after a competently performed standard anti-stress incontinence procedure in females. Many authorities in this country would point to the high degree of success of the pubovaginal sling and consider this procedure the next logical step after failed female incontinence surgery.2 It is important the Kaplan-Meier survival curves should be calculated in all medical device reporting and the authors included these important statistics. Unfortunately it appears that survival was construed to mean persistence of the device in patients despite early revision. Our understanding of statistics indicates that the time to first revision is the time to failure. Survival is meant to be freedom from revision. Thus, survival is overestimated. Based on the numbers in this study we estimate that overall 10-year survival was less than 30% and 10-year mechanical survival was less than 44%. The authors diligently reported personal experience with each clinical application of the artificial urinary sphincter. I appreciate their observations of the reasons for success and failure. However, in my view the section on suggested device improvements seems opinionated and unrealistic, and does not explore or acknowledge the complexity involved in medical device enhancement. Steven K. Wilson 2010 Chestnut St. Van Buren, Arizona This report has several excellent messages for surgeons contemplating using the artificial urinary sphincter for the first time as well as recent implant surgeons who may not have enough long-term experience tackling the many potential problems of an artificial urinary sphincter. Proper selection of patients is essential. Pelvic radiation of any type is an absolute contraindication to implantation of the artificial urinary sphincter at the bladder neck. My rule is reinforced by the experience of the authors, revealing a 100% erosion/infection rate in all females who had radiation to the cervix. However, it is not a contraindication in men when the sphincter is placed in the bulbous urethra as long as the urethra does not show signs of radiation urethritis (pale neovascularized bulbous urethra on endoscopy) and the radiated bladder has a low pressure capacity of at least 150 ml. (good compliance). Likewise, in radiated cases I use a 51 to 60 cm.
LONG-TERM OUTCOME OF ARTIFICIAL URINARY SPHINCTERS balloon pressure and I warn the patient that it will not be unusual if total continence is not achieved but to expect to use 1 to 2 pads a day, which is still 75% to 90% improvement. For neuropathic bladder dysfunction, especially the mixed type when augmentation cystoplasty and clean intermittent selfcatheterization are essential components of therapy, I now prefer to delay sphincter implantation because in many cases augmentation and catheterization with bladder relaxants will control the incontinence, thereby eliminating the need for the sphincter. The authors’ experience also attests to this strategy as in several of their patients who had concomitant artificial urinary sphincter implant and cystoplasty the sphincter was subsequently removed and yet the patient was still continent. They probably did not need it in the first place. However, in a small proportion of cases of neuropathic bladder and sphincter dysfunction I will implant the artificial urinary sphincter in those with adequate capacity areflexic bladder and a patulous paralytic sphincter. The practice of implanting the cuff only at the time of augmentation for fear of making it difficult to implant the cuff later is unfounded. As long as we do not dissect the bladder neck and proximal urethra at the time of augmentation (which should not occur), then this area will remain untouched and subsequent operation to free the bladder neck should not be difficult. Patients who are incontinent after prostatectomy but have good bladder function and a normal bulbous urethra (screened by a simple cystometrogram and flexible cystoscopy) without bladder neck contracture are the ideal candidates for artificial urinary sphincter implantation. The result of the authors and the many other previous reports attest to a high success rate. For the beginners, this will be the best group of patients to gain confidence regarding artificial urinary sphincter implantation. Implantation at the bladder neck especially in women who have undergone multiple previous bladder operations from a vaginal and suprapubic approach is an extremely challenging technical procedure. It should be performed by those who have significant experience in this area and not by an occasional implant surgeon. However, women in whom all other surgical measures have failed should not be denied the option of an artificial urinary sphincter because the outcome is excellent in the hands of those who perform implantation routinely. In the present series if you exclude those patients who had radiation, the outcome will be as good as the outcome in other categories. Once a surgeon embarks on a sphincter implantation program, he/she must realize that this program is for the entire duration of your practice as there is a need for life-long surveillance. As the data suggest, potential complications can occur years after a successful implantation. Therefore, the surgeon must be alert and expert in troubleshooting the artificial urinary sphincter. However, with diligent followup and timely management, these patients can expect the sphincter to provide an effective long-term continence status as reported by the authors.
Ananias C. Diokno Department of Urology William Beaumont Hospital Royal Oak, Michigan 1. Brito, C. G., Mulcahy, J. J., Mitchell, M. E. et al: Use of a double cuff AMS800 urinary sphincter for severe stress incontinence. J Urol, 149: 2183, 1993 2. Leach, G. E., Dmochowski, R. R., Appell, R. A. et al: Female Stress Urinary Incontinence Clinical Guidelines Panel Summary report on surgical management of female stress urinary incontinence. J Urol, 158: 875, 1997 REPLY BY AUTHORS Our series refers to our first 100 cases, which were treated at the beginning of our learning curve. Subsequently, we learned that pelvic radiation is an absolute contraindication to implantation of the artificial urinary sphincter at the bladder neck but women are still being treated in this manner elsewhere. Likewise we learned that increasing balloon pressure has disappointing results, and the use of 2 cuffs in tandem has not been much more successful in our experience. It is incorrect to suggest that our patients with neuropathic bladder did not need an artificial urinary sphincter, as they all had objective urodynamic evidence of sphincter weakness incontinence and would not have had the device implanted otherwise. Likewise we do not agree that the outcome of sphincter implantation in women who have had multiple previous bladder neck procedures for stress incontinence is as good as the outcome in other situations. The procedure is technically demanding, and our results show that the more surgery these women undergo the worse the outcome when a sphincter is finally implanted, which is why an artificial urinary sphincter should be considered sooner. We agree that these women should not be denied the option of the artificial sphincter when intractable incontinence is the only alternative. On the subject of stress incontinence, there is a high degree of success with the pubovaginal sling but for many urologists, particularly in the United States, this is the first logical step in the treatment of stress incontinence and not the next logical step. We have stressed that an artificial sphincter should only be considered when standard anti-incontinence surgery, including a pubovaginal sling, has failed. The time to first revision is the time to failure if one is being semantically correct statistically. However, our patients classified as having a revision are those who are continent with the artificial sphincter but prefer to be more continent. Therefore, the device has not failed but has simply not given as good a result as would be desired. Given that the artificial urinary sphincter device is not a single component but one with a range of pressure balloons that can be used, we do not think it unreasonable to use the term survival in our article. Our section on suggested device improvements is opinionated but it is neither unrealistic nor does it fail to take into account the complexity involved in medical device development, which we have considered in developing our own artificial sphincter, and which will be the subject of a future publication.