Dynamic bladder outlet obstruction (BOO) was induced in adult male rhesus monkeys with a mean weight of 7.5 kg by implanting a vascular occlusive cuff mated to a subcutaneous access port around the bladder neck. Varying degrees of obstruction were created by infusing increasing volumes of isotonic contrast. The amount of obstruction was quantified by the %-decrease in open area of the cuff for increasing volumes. Three levels of obstruction were induced corresponding with Grade I = 11.4%, Grade II = 43.6% and Grade III = 70%. Significant urodynamic changes in the bladder function were observed particularly with Qmax (3.8 ml/sec in control versus 2.08 in BOO, p = 0.003), voiding time (40.8 sec in control versus 67.1 sec in BOO, p = 0.001), bladder capacity (144 ml in control versus 224 in BOO, p = 0.026 and maximum voiding pressure (55.1 cm H2O in control versus 85.6 cm H2O in BOO, p = 0.0451). Additionally, detrusor instability appeared in one monkey (25% of the animals), but no residual urine was collected from any of the obstructed monkeys. Also, there were no significant urodynamic changes between early and late grade-III obstruction. Significant changes of the bladder function could be anticipated by changing the grade (severity) of obstruction and not by the duration of the same grade. Our system can accurately determine the functional state of the detrusor, enhancing its correlation with in-vitro, biochemical, pathological and molecular studies of BOO.
Showing the most recent 10 out of 352 publications
