Urodynamic evaluation of hypospadias repair

Abstract

Purpose: 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.

Materials and methods: 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.).

Results: 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.

Conclusions: 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.