Congenital Anomalies Of The Urinary System In Human

Congenital anomalies of the urogenital tract are considered the third most common system anomalies after the skeletal and cutaneous ones. They account for one third of all congenital anomalies. Anomalies of the urinary system can affect 3% of live births .this wide prevalence is due to the fact that, renal development is characterized by proliferation, migration, induction and cell differentiation taking along time and is subjected to topographic changesCongenital anomalies of the kidneys:- As regards anomalies of number, URA as well as BRA is due to absence of nephrogenic cord or failure of ureteric bud to develop. BRA is less common and is incompatible with life. The Supernumerary kidney is rare and is considered an accessory organ with its own collecting system and blood supply.- As regard anomalies of volume, congenital polycystic kidney is common; the incidence of ADPKD is more than the ARPKD, is less progressive in course and usually doesn’t cause renal failure until adulthood.- The multicystic dysplastic kidney presents a collection of tense non communicating cysts of variable size (bunch of grapes).- As regards anomalies of the form and fusion the horseshoe kidney and crossed fused renal ectopia are the most frequent. The horseshoe kidney is usually lower than normal and is due to change in the orientation of the migratory kidneys as their ascent is prevented by the root of the inferior mesenteric artery.- As regards anomalies of rotation, abnormal rotation of the kidney is of three types; incomplete with the hilum facing posteriorly, excessive rotation and reverse rotation in which the hilum faces laterally.Congenital anomalies of the ureterAre considered some of the most significant anomalies in all pediatric urology because they directly affect renal function.- The laterally placed ureteral orifice is usually due to origin of the ureteric bud from a caudal point on the mesonephric duct.- The ectopic ureter describes termination of the ureter into the bladder neck or distally into one of the mesonephric duct structures.It is due to the proximal origin of ureteric bud and failure of its absorption into the bladder.- Megaureter is an enlarged ureter which is either primary (due to congenital alteration at the vesicoureteric junction) or secondary due to abnormality of the urinary bladder or urethra).- Several vascular lesions due to anomalies of the vascular system can cause ureteral obstruction as in the preureteral vena cava.- Congenital ureteral stenosis can occur in one of three sites; just above extravesical junction, ureteropelvic junction and midureter at the pelvic brim.- Double ureters can result from division of ureteric bud.Congenital anomalies of the urinary bladderAnomalies of the urachus include urachal fistula in which the lumen of intraembryonic of the allantois persists. If part only persists, urachal cyst can occur. If the lumen in the upper of the urachus persists, urachal sinus can occur.- Exstrophy of the bladder is a ventral body wall defect in which the bladder mucosa is exposed. Epispadias is a constant feature exstrophy of the bladder is part of a spectrum of anomalies involving the urinary tract, the genital tract, the musculoskeletal system and sometimes the intestinal tract. Exstrophy of the cloaca is a worse severe ventral body wall defect in which the migration of mesoderm to the body wall is inhibited and the tail fold fails to progress. It is a rare anomaly.Congenital anomalies of the urethra- Male hypospadias is an abnormal ventral opening of the urethral meatus which may be located anywhere from the ventral aspect of the glans penis to the perineum. It is due to incomplete closure of the urethral folds on the under surface of the penis. Etiologic factors for hypospadias may include endocrinological, environmental or maybe a manifestation of arrested development. Recently, disruption of fibroblast growth factor 10 (FGF-10) gene is the cause of hypospadias.- Female hypospadias is characterized by short urethra with ectopic extraurethral opening. it is due to fissure of the posterior wall of the urethra..