Late decompensation of neobladder

We report on 6 patients in whom we constructed detubularized ileocolonic neobladders in conjunction with cystectomy to treat invasive transitional cell carcinoma of the bladder. The patients had delayed complete or partial decompensation of the neobladder after an initial interval of normal voiding. Two patients experienced complete decompensation with inability to empty in the absence of urodynamic, cystoscopic or radiographic evidence of outlet obstruction. The other 4 patients had greater than 400 cc residual urine without evidence of outlet obstruction. The mean interval to decompensation after the initial period of normal voiding was 12.8 months (range 4 to 21). All 6 patients had a reservoir capacity of greater than 800 cc. We also constructed neobladders in 3 other patients for similar indications. These 3 patients have a neobladder capacity of less than 800 cc and all are voiding to completion with followup of 19 to 32 months. We hypothesize that neobladder decompensation is due either to creation of an excessively large pouch alone or in combination with a poor Valsalva ability. Until we know the neobladder capacity required for continence that will simultaneously allow for complete emptying, all patients should be advised of the possible need for intermittent self-catheterization. Urological followup should include monitoring of post-void residual urine volume to detect failure to empty early before irreversible decompensation occurs.