Instability in the augmented bladder

Abstract

Despite generous augmentation with bowel, some bladders demonstrate persistent instability. To determine whether this phenomenon arises in the vesical or intestinal components of the augmented bladder, the cystometrograms of 181 children exhibiting neuropathic bladders were reviewed; 67 that showed evidence of detrusor hyperactivity were selected for comparison with cystometrograms of 33 children in whom enterocystoplasty had been performed. In 19 cases, a within-subject comparison was possible. Five independent variables representing bladder capacity and intrinsic activity were chosen for the study. There was a significant difference in the characteristics of bladder activity between unaugmented and augmented bladders. The results suggest that instability in the augmented bladder is attributable to intestinal rather than detrusor activity.As a technique of either augmenting or replacing the bladder, enterocystoplasty has achieved generally good results, with postoperative urinary control as represented by normal voiding or by intermittent catheterisation usually being satisfactory. However, a small number of patients continue to suffer varying degrees of incontinence. In some cases, this is due to low-outflow tract resistance resulting in stress incontinence, whereas in others, compliance and capacity continue to be inadequate because the bladder seems to remain unstable despite the augmentation. To elucidate this problem, the results of cystometrographic examinations of children exhibiting unaugmented versus augmented bladders were compared. Patients and methods