pediatrics
Renal Anomalies
Fusion anomalies
With fusion anomalies, the kidneys are joined, but the ureters enter the bladder on each side. These anomalies increase the risk of ureteropelvic junction obstruction, Vesicoureteral Reflux (VUR) , Horseshoe kidney,the most common fusion anomaly, occurs when renal parenchyma on each side of the vertebral column is joined at the corresponding (usually lower) poles; an isthmus of renal parenchyma or fibrous tissue joins at the midline. The ureters course medially and anteriorly over this isthmus and generally drain well. Obstruction, if present, is usually secondary to insertion of the ureters high in the renal pelvis. Pyeloplasty relieves the obstruction and can be done without resecting the isthmus. Crossed fused renal ectopiais the second most common fusion anomaly. The renal parenchyma (representing both kidneys) is on one side of the vertebral column. One of the ureters crosses the midline and enters the bladder on the side opposite the fused kidneys. When ureteropelvic junction obstruction is present, pyeloplasty is the treatment of choice. Fused pelvic kidney(pancake kidney) is much less common. A single pelvic kidney is served by two collecting systems and ureters. If obstruction is present, reconstruction is needed. 