THE EFFECTS OF DETUBULARIZATION AND OUTFLOW COMPETENCE IN SUBSTITUTION CYSTOPLASTY

Objective To assess the effects of detubularization and outflow compet ence on the clinical and urodynamic results of patients undergoing sub stitution cystoplasty. Patients and methods The study included 142 pat ients undergoing orthotopic substitution cystoplasty, of whom 85 under went a 'straight' and 57 a detubularized substitution cystoplasty usin g the ileo-colonic segment. All were assessed clinically and by videou rodynamic studies before and after surgery. Results In patients voidin g spontaneously, detubularization produced a capacity 38% greater than that found with a 'straight' cystoplasty, but there was no difference in the contractility of the substitute bladder between the groups. In patients requiring clean intermittent self-catheterization to empty, outflow competence was a more important factor in increasing capacity and reducing contractility. Conclusions Detubularization produces a mo dest increase in bladder capacity but far less than that predicted by mathematical models. It has no substantial effect on contractility whe n compared with straight substitution cystoplasty. The effects of detu bularization on both capacity and contractility are less than the 'chr onic retention' effect produced by increasing outflow competence. Detu bularization is therefore only one of several factors that influence t he results of substitution cystoplasty.