Behaviour of the human bladder during natural filling: the Newcastle experience of ambulatory monitoring and Conventional Artificial Filling Cystometry

Conventional Artificial Filling Cystometry (CMG) is the Gold Standard investigation of detrusor function although the findings are limited by the constraints of rapid rates of filling with artificial filling media in conditions of restricted mobility and the clinical environment. Recent advances in technology have allowed the use of ambulatory monitoring (AM) of detrusor function during which the bladder fills at natural rates with urine whilst the patient is able to exercise and perform normal daily activities outside the clinical environment. Comparative studies of CMG and AM in the Department of Urology at the Freeman Hospital, Newcastle-upon-Tyne in recent years have shown interesting differences in the results obtained between the techniques. During AM the bladder pressure rise on filling is seen to be lower and associated with a greater incidence of spontaneous phasic detrusor activity than during CMG, whilst detrusor contraction pressures during the voiding phase following natural filling, are generally seen to be higher than during CMG. Several groups of patients, including men with neuropathic bladder disorder, chronic retention of urine and bladder outflow obstruction together with a group of asymptomatic healthy volunteers have been studied and the results presented.