Enterocystometry: impact of filling rate

We evaluated different enterocystometric parameters at different filling rates.

A total of 20 male patients who underwent radical cystoprostatectomy and orthotopic detubularized ileal reservoirs with at least 1 year of followup were the material of this study. Enterocystometry was done with a slow fill rate (10 ml. per minute). Under the same circumstances it was then repeated with a medium fill rate (50 ml. per minute).

Maximum enterocytometric capacity for slow fill was significantly lower than for medium fill (median 475 versus 610 ml., p <0.001). Volume at first uninhibited contraction for slow fill was significantly lower than for medium fill (median 247 versus 450 ml., p <0.001). Volume at first desire for slow fill was significantly lower than for medium fill (median 306 versus 436 ml., p = 0.012). Moreover, volume at highest contraction for slow fill was significantly lower than for medium fill (median 451 versus 557 ml., p <0.001). Other pressure parameters were comparable without any significant difference between the 2 filling rates. The difference in contraction frequency calculated in the last 100 ml. of filling was significantly higher for slow than for medium fill enterocystometry.

Higher rates of filling during enterocystometry resulted in significantly higher capacity, delayed onset of contractions, delayed onset of first desire (or sense of fullness) and delayed onset of highest contraction. Therefore, we recommend slower filling rates during enterocystometric studies, which mimics physiological states and allows accurate and earlier identification of enterocystometric changes that could be masked by higher rates of filling.