Abnormalities of the ureteral bud.

The development and incorporation of the ureteric bud into the developing bladder is a complex process, and it is influenced by events occurring at the same time in the development of other systems in the perineum. Knowledge of the embryology of the ureteric bud and associated wolffian duct is the key to understanding the development of the entire genitourinary system. If the normal embryology is understood, the dysembryogenesis that results in many of the common anomalies of the lower urinary system is simplified. Many of the concepts proposed in this discussion are well substantiated, others are more difficult to prove conclusively. It is believed, however, that the embryologic approach provides a simplified understanding of many of the common problems encountered in pediatric urology. The key in clinical practice to the diagnosis and understanding of these defects is the cystoscopic examination. Careful assessment of the orifice's position, appearance, and tunnel length will allow the interpretation of how the abnormality came about, and also provides valuable information concerning the state of the associated renal segment. This in turn allow better therapeutic management of the problem based on the knowledge of the severity of the renal anomaly associated with the abnormality found in the bladder.