Objective: To evaluate natural filling cystometry in infants and young children.
Patients and methods: The study group comprised 37 infants and young children (mean age, 4.1 years) with various urological conditions. Suprapubic catheters were used in all patients with urethral sensation. Natural filling urodynamic (NFU) studies were performed using an ambulatory recorder and with an observer present throughout. For comparison, 17 of the 37 patients also had slow filling conventional cystometry (CMG).
Results: All NFU studies were successfully completed and the great majority of patients were unaffected by the investigation procedures. In comparison with conventional cystometry there were significant differences. For NFU, there was a lower bladder capacity (means, NFU 122 mL vs CMG 188 mL, P < 0.03); lower pressure rise on filling (means, NFU 5.7 cmH2O vs CMG 16.1 cmH2O, P < 0.001) and higher maximum detrusor pressures during micturition (means, NFU 130 cmH2O vs CMG 78 cmH2O, P < 0.01). Voiding efficiency was also slightly greater with NFU compared with CMG. Detrusor instability was recorded in five patients only during NFU and in two other patients only during CMG.
Conclusion: A natural filling cystometry method which incorporates an unobtrusive recording system is likely to be superior to conventional CMG for assessing bladder function in infants and children. This is because (i) bladder function is investigated in near to natural conditions, (ii) the patients are mostly unaffected by the investigation procedures, (iii) there are significant differences between NFU and CMG in the measurements obtained, indicating that CMG may give false indices of bladder function.