Urodynamic evaluation of hypospadias repair

We performed a cross-sectional evaluation of voiding in a population undergoing hypospadias repair to determine whether patients had urinary obstruction at various intervals of followup after the last operation.

Of approximately 600 patients undergoing hypospadias repair at our department during a 30-year interval 175, 40 months to 66 years old were evaluated. Therefore, we created a cross-sectional study group for evaluation of voiding function. All patients had undergone the final operation for hypospadias at least 1 year previously and were toilet trained. Severity of the initial hypospadias was scored together with the operative technique. Parameters evaluated were medical history, physical examination and uroflowmetry using a rotating disk. Uroflowmetry data (maximum flow rate and voided volume) were plotted in age-related nomograms in 4 different age groups: less than 8 (28 patients), 9 to 14 (18), 15 to 21 (39) and more than 21 (91) years old. All flow charts were evaluated by 2 of us (J. F. A. v. d. W. and E. B.).

The severity of initial disease was grade 1 in 30% of the patients, grade 2 in 57%, grade 3 in 10%, grade 4 in 2% and unknown in 2%. The operative technique performed was a van der Meulen repair in 113 patients (65%), a combined Byars-Denis Browne repair in 56 (32%) and miscellaneous in 6 (3%). According to the uroflowmetry nomograms there was a tendency for an increased number of patients to have a normal maximum flow rate with increasing age. A total of 14 patients had a flow curve that suggested distal urethra obstruction and none was symptomatic. There was no difference in uroflowmetry characteristics regarding the operative technique.

No difference in uroflowmetry could be established among the operations. There seemed to be a tendency towards improvement in uroflowmetry with increasing followup. There was no direct relationship between low maximum flow rates and clinical apparent obstruction.