[Distal detubularized sigmoidoplasty (Canarian neobladder). Midterm functional evaluation]

The aim of this report is to evaluate the medium term clinical and urodynamic results of the distal detubularized sigmoid neobladder, which we have called the "Canarian neobladder".

Since April, 1992, we have performed 26 orthotopic neobladder substitution using this particular technique. Ten patients were excluded from the study: two patients with early cancer progression; one female patient; one patient that had died a few days after the operation and 6 patients with less than 16 months follow-up. The remaining 16 patients were evaluated and had a mean follow-up of 22 months (range 6-54). We have performed clinical, urodynamic, radiographic and metabolic evaluation every six months during the first year and every 12 months thereafter. Clinical evaluation included daytime frequency, daytime and night-time urinary incontinence, urge and patient satisfaction with the clinical results. Flowmetry, cystometry and pressure-flow test were performed. The upper urinary tract was evaluated by renal ultrasound or pyelography. Entero-ureteral reflux was discarded by cystography. The International Continence Society terminology was utilized and clearly specified if otherwise.

87.5% of the patients were continent during the daytime and only two cases had diurnal urinary incontinence. Seventy-five percent of the patients had night-time incontinence and required external devices for its management. At two years follow-up, the mean diurnal frequency was 180 minutes and the mean bladder capacity was 338.2. First sensation was noted at 70.6% of bladder capacity. The neobladder pressure at maximum capacity during the filling phase was less than 30 cm H2O in all cases. Involuntary bladder contractions were demonstrated during cystomanometry in 93.7%. The pressure-flow test demonstrated neobladder contraction in 50% of cases and combined with abdominal straining in 50%. The foregoing allowed application of passive urethral resistance ratio (PURR) parameters, showing mean PURR initial values of 39.1 cm H2O and mean PURR curvature values of 0.17 cm H2O (mil/sec)2. The mean postvoiding urine was 37.5 ml. We diagnosed entero-ureteral reflux in 25% of patients and upper urinary tract dilatation due to a distal ureteral stricture in 2 patients. Mild outlet obstruction was diagnosed in 50% of the cases and were submitted to endoscopic section of the entero-urethral anastomosis.

The distal sigmoid detubularized neobladder achieves a high rate of daytime continence with adequate frequency. However, the night-time incontinence rate was also high. The neobladder functional capacity remained stable throughout follow-up. Voiding was obtained as a result of neobladder contraction; thus postvoiding urine was minimal and patients did not require self-catheterization.