Voiding cystourethrography in boys. Does the presence of the catheter during voiding alter the evaluation of the urethra?
We determined whether the presence of the catheter during the voiding phase of voiding cystourethrography alters the evaluation of the urethra concerning the normal structures as well as pathological findings, especially posterior urethral valves. A total of 123 males 3 days to 16 years old (median age 2.6 months) underwent voiding cystourethrography. Urethral catheterization was performed in all cases. Four views were taken during the voiding phase with and without the catheter in place. Only 80 patients had available results. These examinations were studied with special attention to the normal structures and pathological findings. A total of 36 examinations (45%) were normal. Pathological findings were observed in 44 patients (55%), with abnormal vesical findings and/or vesicoureteral reflux in 33 (41.25%). In 11 patients (13.75%) 12 urethral abnormalities were found (posterior urethral valves 3, hypospadias 4, prostatic utricle 1, verumontanum polyp 1, prune belly syndrome with urethral dilatation 1, imperforate anus with urethral fistula 1 and urethral duplication 1). In all cases excluding those involving hypospadias there was no difference between the views with and without the catheter. However, concerning the normal structures, the verumontanum and fossa navicularis were better delineated without the catheter in 27% and 33% of cases, respectively. Our study shows that a urethral catheter does not alter the diagnosis of abnormalities of the posterior urethra but may hamper the observation of normal structures or abnormalities of the anterior urethra.