The so-called Y-type urethral duplication: anatomical insights through controversial terminology

Abstract

Abstract Background Y-type urethral duplication is a term frequently used to describe a rare condition in the male associated with double urinary stream: a weak interrupted urinary stream through a hypoplastic penile urethra, while the main urine flow is through the anus/perineum via accessory posterior channel. Fortunately, the advent of MRI has provided a powerful tool to study these anomalies in depth and on multiple planes. The study included boys presenting with abnormal micturition through the anus beside weak interrupted urine stream through the penis. Investigations included pelviabdominal ultrasound to screen for possible associated upper urinary tract anomalies, conventional contrast X-ray studies, and pelvic MRI. Results During the period between 2016 through 2021, the study included two newly diagnosed cases with abnormal communication between the lower urinary tract and the anus (the so-called Y-type urethral duplication), in addition to one previously reported case whose preoperative imaging studies (including pelvic MRI) were available for analysis. Different surgical solutions have been applied for each case. Hypoplasia was not only restricted to the penile urethra but also affected the corporeal bodies of the penis with variable degrees. In two cases, only a single corporeal body could be identified. In another case, the three corporeal bodies were present but appeared distorted (irregularities and interruption of corporeal bodies). Conclusion In our present study, pelvic MRI examination clearly unveiled significant degrees of corporeal dysgenesis among cases diagnosed as Y-type urethral duplication that would strongly suggest these cases to belong to the same disease spectrum of penile dysgenesis/agenesis.