The effects of detubularization and outflow competence in substitution cystoplasty

To assess the effects of detubularization and outflow competence on the clinical and urodynamic results of patients undergoing substitution cystoplasty.

The study included 142 patients undergoing orthotopic substitution cystoplasty, of whom 85 underwent a 'straight' and 57 a detubularized substitution cystoplasty using the ileo-colonic segment. All were assessed clinically and by video-urodynamic studies before and after surgery.

In patients voiding 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.

Detubularization produces a modest increase in bladder capacity but far less than that predicted by mathematical models. It has no substantial effect on contractility when compared with straight substitution cystoplasty. The effects of detubularization on both capacity and contractility are less than the 'chronic retention' effect produced by increasing outflow competence. Detubularization is therefore only one of several factors that influence the results of substitution cystoplasty.