range or late perforation, and found that the incidence ofearly perforations (less than 2 years postoperatively) in-creased during the 3 eras we examined. We believe that thisoutcome is due to increasingly aggressive reconstructive sur-gery of the bladder neck. This finding reflects the change inpractice pattern, since continence is now an accepted indi-cation for surgery, as opposed to the protection of the uppertracts. Unfortunately, we cannot quantify this finding, asour urodynamic data are lacking.

This outcome was reflected in our data showing the in-creased risk associated with bladder neck surgery. We be-lieve that bladder neck surgery is a legitimate risk, since itcan cause high bladder pressures with fixed outlet resis-tance. Unfortunately, we do not have urodynamic data tocorroborate this theory, because postoperative urodynamicswere not routinely done. In contrast, only 1 patient with asuburethral sling---which is not as disruptive or occlusive asother bladder neck alterations---suffered a perforation. How-ever, a significant selection bias existed, whereby those pa-tients undergoing a sling procedure were more likely to haveonly moderate incontinence, and perhaps less likely to havehigh pressure detrusor contractions. Nonetheless, slingsmay allow a low pressure “pop off” and result in early incon-tinence instead of perforation.

We have previously reported the increased risk with theuse of sigmoid.1 However, this finding has been disputed.13

Since detubularization and reconfiguration were not inwidespread use before 1984, this difference is a likely sourceof the increased risk and discrepancy with other reports.4,14

Therefore, these augmentations may have been at an espe-cially increased risk, not necessarily due to the specific gas-trointestinal segment, but to increased pressure fromunmitigated peristaltic contractions.

Unfortunately, even with a review of all pertinent oper-ative records we were unable to determine conclusivelywhen detubularization and reconfiguration were used. Allbut 2 of the perforations with sigmoid augmentations oc-curred in the first 167 cases of our series, another potentialconfounding factor.

Cutaneous catheterizable channels have been observed toimprove patient compliance,15 which is probably the meansby which they decreased the incidence of perforation seen inour study. However, if we omit those perforations that oc-curred with sigmoid augmentation, the effect is attenuated.Unfortunately, due to the nonrandomized retrospective na-ture of our review, we were unable to determine definitivelywhich was the most dependent variable. Nevertheless, if thepresence of a channel is protective, it may act by maintain-ing lower long-term intravesical pressures. Therefore, thebenefit would be more apparent during a longer time course,and the true effect has yet to be seen.

Unfortunately, the confounding variables in our reviewpreclude us from definitively knowing which of our variablesis the most important. Therefore, as with our other findings,we present these as observations of a large surgical experi-ence, and a catalyst for further discussion and investigation.

CONCLUSIONS

The incidence of spontaneous bladder perforation in anaugmented bladder is low (8.6%) but is not insignificant,and remains throughout the life of the augmentation. Ourreview was based on the largest published series of blad-

der augmentations with the longest followup. Despite theinherent difficulties in a retrospective review of this mag-nitude, we believe that it provides significant insight intospontaneous perforations. The risk in our population de-creased with the use of ileum and a catheterizable chan-nel, and increased with bladder neck surgery. However,the historical nature of this review includes several inher-ent biases, and these findings cannot be translated intoeither indications or contraindications. Instead, we shareour experience as observations that merit study in a morerigorous manner.

REFERENCES

1. Pope, J. C., Albers, P., Rink, R. C., Casale, A. J., Cain, M. P.,Adams, M. C. et al: Spontaneous rupture of the augmentedbladder: from silence to chaos. Presented at annual meetingof European Society for Pediatric Urology, Istanbul, Turkey,April 15, 1999

2. Elder, J. S., Snyder, H. M., Hulbert, W. C. and Duckett, J. W.:Perforation of the augmented bladder in patients undergoingclean intermittent catheterization. J Urol, 140: 1159, 1988

3. Rushton, H. G., Woodard, J. R., Parrott, T. S., Jeffs, R. D. andGearhart, J. P.: Delayed bladder rupture after augmentationenterocystoplasty. J Urol, 140: 344, 1988

4. Bauer, S. B., Hendren, W. H., Kozakewich, H., Maloney, S.,Colodny, A. H., Mandell, J. et al: Perforation of the aug-mented bladder. J Urol, 148: 699, 1992

5. Anderson, P. A. and Rickwood, A. M.: Detrusor hyper-reflexia asa factor in spontaneous perforation of augmentation cysto-plasty for neuropathic bladder. Br J Urol, 67: 210, 1991

6. Crane, J. M., Scherz, H. S., Billman, G. F. and Kaplan, G. W.:Ischemic necrosis: a hypothesis to explain the pathogenesis ofspontaneously ruptured enterocystoplasty. J Urol, 146: 141,1991

7. Rosen, M. A. and Light, J. K.: Spontaneous bladder rupturefollowing augmentation enterocystoplasty. J Urol, 146: 1232,1991

8. Reinberg, Y., Manivel, J. C., Froemming, C. and Gonzalez, R.:Perforation of the gastric segment of an augmented bladdersecondary to peptic ulcer disease. J Urol, 148: 369, 1992

9. DeFoor, W., Tackett, L., Minevich, E., Wacksman, J. and Shel-don, C.: Risk factors for spontaneous bladder perforationafter augmentation cystoplasty. Urology, 62: 737, 2003

10. Bertschy, C., Bawab, F., Liard, A., Valioulis, I. and Mitrofanoff,P.: Enterocystoplasty complications in children. A study of 30cases. Eur J Pediatr Surg, 10: 30, 2000

11. Krishna, A., Gough, D. C., Fishwick, J. and Bruce, J.: Ileocys-toplasty in children: assessing safety and success. Eur Urol,27: 62, 1995

12. Flood, H. D., Malhotra, S. J., O’Connell, H. E., Ritchey, M. J.,Bloom, D. A. and McGuire, E. J.: Long-term results andcomplications using augmentation cystoplasty in reconstruc-tive urology. Neurourol Urodyn, 14: 297, 1995

13. Shekarriz, B., Upadhyay, J., Demirbilek, S., Barthold, J. S. andGonzalez, R.: Surgical complications of bladder augmenta-tion: comparison between various enterocystoplasties in 133patients. Urology, 55: 123, 2000

14. Mitchell, M. E.: Personal communication, 200515. Horowitz, M., Kuhr, C. S. and Mitchell, M. E.: The Mitrofanoff

catheterizable channel: patient acceptance. J Urol, 153: 771,1995

EDITORIAL COMMENT

The authors present the largest series of bladder augmen-tation to date and report on one complication of this proce-

SPONTANEOUS BLADDER PERFORATIONS1470

dure—bladder perforation. Isolating one complicationsimplifies the article but it is hard to judge the benefits andharms of bladder augmentation in this series. I would haveliked to have seen some reference to the number of patientswho had development of intestinal obstruction, metabolicacidosis, bladder stones, etc. Similarly, the benefits, includ-ing preservation of renal function and improved continence,need to be documented carefully. Hopefully, these topics willbe the subject of a future article.

The authors note an increased incidence of bladder per-foration with bladder neck reconstruction, compared to asling procedure. There was also an increased incidence ofperforation associated with the use of sigmoid colon com-pared to ileum. Adding a catheterizable channel appeared todecrease the incidence of perforation. The authors indicatethat all of these variables are related, and it is difficult totease out the independent variable. Nevertheless, this re-port raises some interesting questions for further study. Forexample is there a demonstrable urodynamic difference inleak point pressures between a patient who has undergonebladder neck reconstruction and one who has undergone asling procedure? Perhaps the detrusor leak point pressure islower after a sling procedure and this decreased pressureprovides some protective effect against perforation. Alterna-tively, it may be that patients who have undergone bladderneck reconstruction find it more difficult to perform cleanintermittent catheterization.

This series provides the definitive answer for the perfo-ration rate in bladder augmentation. However, it remainsdifficult to answer the most important question—If I un-

dergo this operation, how likely is it to help me, and what isthe chance that I will suffer a complication?

Grahame SmithDepartment of Urology

Children’s Hospital at WestmeadWestmead, Australia

REPLY BY AUTHORS

We agree that by describing only bladder perforations, wepotentially offer a simplified view of complications of bladderaugmentations but this serious entity warrants an in-depthdiscussion. We agree that more precise urodynamic evalua-tion of this patient population regarding the leak point pres-sure of the various bladder neck procedures would beinvaluable. We also look forward to the further investigationof the risk factors (bladder neck surgery, type of segmentand effect of a catheterizable channel) that we have elicited.

We recently presented a more comprehensive review ofcomplications that have occurred in the augmented bladder,namely malignancy, perforations, the need for a second aug-mentation, surgical bowel obstruction and bladder calculi.1

We hope that this, along with other reviews, will allow moreinsight into the true prevalence of complications in thispopulation.

1. Metcalfe, P. D., Cain, M. P., Gilley, D. A., Misseri, R., Kaefer, M.,Meldrum, K. et al: What is the need for additional bladdersurgery after bladder augmentation in childhood? Presentedat the Section on Urology, American Association of Pediat-rics, Washington, D. C., 2005

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