Is a failure of midline penile fusion much earlier in embryogenesis. An isolated opening of the dorsal (“top”) side of the penis is rare, and most of these children have much more severe defects, involving a small and bifid phallus with bladder exstrophy or more severely, cloacal exstrophy involving the entire perineum. The cause of this defect of early embryogenesis is unknown but does not involve androgens.
Epispadias is an uncommon and partial form of a spectrum of failures of abdominal and pelvic fusion in the first months of embryogenesis known as the exstrophy – epispadias complex. While epispadias is inherent in all cases of exstrophy it can also, much less frequently, appear in isolation as the least severe form of the complex spectrum. It occurs as a result of defective migration of the genital tubercle primordii to the cloacal membrane, and so malformation of the genital tubercle, at about the 5th week of gestation.
The main treatment for isolated epispadias is a comprehensive surgical repair of the genito-urinary area usually during the first 7 years of life, including reconstruction of the urethra, closure of the penile shaft and mobilisation of the corpora. The most popular and successful technique is known as the modified Cantwell-Ransley approach. In recent decades however increasing success has been achieved with the complete penile disassembly technique despite its association with greater and more serious risk of damage
