[Distal detubularized sigmoidoplasty (Canarian neobladder). Midterm functional evaluation].
OBJECTIVE: 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". METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.