Congential Malformation of the Posteriror Urethra

Urethral valves

“…Lowsley [ 5] thought that valves were the result of anomalous junction of the ejaculatory (Wolffian) duct and the prostatic utricle (Müllerian duct): he described fibres attaching themselves around the entire circumference of the urethra in an autopsy specimen. Watson [ 6] deduced that valves represent the fusion of epithelium of the seminal coliculus with the roof of the urethra (the so‐called posterior urethral groove).…”

Posterior Urethral Valves: Theoretical Considerations on Embryological Development

“…As early as 1914, Lowsley [9] believed anomalous devel opment of the Wolffian or Müllerian ducts to be the ori gin of posterior urethral valves because of his histological studies. In cross sections of the fetal urethra, Watson [15] found fibrous bands in the urethra attached to the tip of the colliculus and suggested that early fusion of the colli culus with the urethral roof may result in posterior ure thral valves.…”

“…Looking at the route of posterolateral migration of the Wolffian ducts from an anterior-posterior view, the ducts enter the ure thra at the verumontanum, sheathed in connective tissue which disappears distally. Lowsley [9] found persistence of this connective tissue beyond the verumontanum, con nected to the posterior urethral wall building a crest which causes obstruction to the urethral lumen.…”

Congenital urethral obstruction: the video‐endoscopic perspective

“…Lederer [6] provided two views of the autopsy specimen of an 11‐year‐old patient, concluding that the abnormality was a ‘semicircular diaphragmatic obstruction below the verumontanum’. Lowsley [7] in 1914 found ‘the entire structure is more or less dome shaped, make the term “diaphragm” more appropriate in referring to this anomaly’. Velpeau and Budd, while making the morphological description, certainly did not suggest any specific physiological intent of these lesions to prevent back‐flow of urine, nevertheless the term ‘valves’ has become entrenched in urological literature.…”