Importance of urinary flow studies after hypospadias repair: a systematic review.

A systematic review was performed of publications relating to the results of urinary flow studies after hypospadias repair dating back to 1978, when what appears to be the first publication on this topic was found. The literature search was performed using the key words "hypospadias" combined with "urinary flow", "urine flow", "uroflow", "uroflowmetry", and "long-term". We also reviewed the abstracts and full-length articles cited in the reference list of selected articles. Criteria for inclusion in the present systematic review included descriptions of patient selection, surgical technique, the severity of disease (proximal vs distal), and the method used to determine uroflow, as well as a definition of urethral obstruction. In all, 339 article titles were found. Of these, 25 abstracts appeared relevant and the full text of these articles were reviewed, with 22 of the papers included in this review. Sixteen reports had appeared in the literature since 2001, compared with six between 1978 and 2000, suggesting an increasing interest in this topic. On the basis of the results of the present systematic review, we recommend that asymptomatic children operated on for hypospadias in infancy should have one flow study after toilet training, with that study repeated if the results are abnormal. It appears that early abnormal flows improve spontaneously, so that children operated on after toilet training who are asymptomatic should undergo their first uroflow measurement 1 year after surgery. Children with obstructed flow parameters or borderline flows should be followed until adulthood, until long-term follow up studies clarify the significance of abnormal flow parameters. Given the present findings, we anticipate that in the next two decades urologists will need to treat a number of men with strictures resulting from hypospadias repairs performed in childhood.