The value of urodynamic studies.

may then be taken both to achieve urinary, continence and to preserve upper tract function. The common surgical procedures carried out incluide bladder neck reconstruction, bladder augmentation, and the placement of the artificial urinary sphincter. Perioperative urodynamic studies in children undergoing such procedures are standard practice in most major centres. End stage renal disease in children requiring renal transplantation is associated with lower urinary tract obstruction in as many as 25%. Pretransplant urodynamics in these children will allow, if necessary, the construction of a urinary tract that will not prejudice renal function in the engrafted kidney.2021 Cystometry is indicated in children with reflux where bladder dysfunction is suspected, especially if reimplantation surgery is contemplated, as a relationship may exist between severe vesicoureteric reflux and abnormal bladder activity.22 Cystometry and videocystometry are invasive studies, the latter involving exposure to radiation. Recent advances include the availability of extended night time cystometry,23 with so called physiological filling of the bladder with the patient's own urine.24 More recently ambulatory urodynamics involving a Holter type principle has permitted the recording of bladder pressure over many hours while the child goes about his or her normal activities.25 These studies provide a more sensitive index of lower urinary tract function than conventional cystometry and are of particular use in infants and younger children (such as those under the age of 5 years) who are often unable to cooperate with the more traditional techniques. Urodynamic studies in general, and cystometric investigations in particular, are fundamental to the initial and on-going management of many children with urological abnormalities, particularly those with neuropathic bladder dysfunction. The value of these studies in children depends on careful patient selection together with sympathetic management of the child during the study.