Evaluation of cervico-urethral obstruction with ambulatory pressure/flow studies: an alternative to conventional pressure/flow studies?

Most of the urodynamic studies are conducted in the laboratory during a brief recording time and under nonphysiological conditions and, thus, may fail to unfold the nature of existing pathological conditions of the lower urinary tract; false positives and false negatives are possible. To overcome some of the difficulties associated with conventional P/F studies we have developed, with the cooperation of Medical Measurement System company, Entschede, The Netherlands, a portable system (UDS 2000) for ambulatory monitoring of intravesical pressure, abdominal pressure and EMG connectable with a weight transducer flowmeter that permits performing Holter P/F measurements. We compared the results obtained with conventional P/F studies and with the Holter P/F studies in 58 BPH patients. During the filling phase we observed a slightly increased number of stable detrusors with Holter P/F recording (46 vs 42); conversely, the number of patients suffering from urge incontinence was the same (7 pts). During the voiding phase, out of 45 patients considered obstructed at conventional P/F study, only 42 were really urodynamically obstructed (93.3%), while 3 other patients had borderline obstruction. Four patients with borderline obstruction at conventional P/F study were considered nonobstructed after Holter P/F.