The problems of substitution cystoplasty.

Substitution cystoplasty was performed in 157 patients aged 4 to 71 years; 62% suffered no post-operative complication. The commonest complication was sphincter-weakness incontinence, found in 18%, mainly in patients having a cystoplasty for interstitial cystitis; it was rare for the patient to complain of this incontinence. Ten per cent suffered incontinence due to colonic overactivity and this occurred in patients with neuropathic sphincter-weakness incontinence or an artificial sphincter; all of these patients complained of their incontinence. This was corrected by "patching" in all cases. Voiding difficulties requiring clean intermittent self-catheterisation occurred in 15%. More worrying was the universal finding, when looked for by blood gas analysis, of a metabolic acidosis with respiratory compensation. It was concluded that in the absence of neuropathy, sphincter weakness or an artificial sphincter, an unmodified ileocaecal segment substitution cystoplasty is adequate; in the presence of neuropathy, sphincter weakness or an artificial sphincter, a "pouch" type of substitution cystoplasty should be performed. All patients should have blood gas analyses from time to time as part of their routine post-operative follow-up.