Horseshoe Kidney

Overview


Plain-Language Overview

Horseshoe Kidney is a condition where the two kidneys are joined together at the lower ends, forming a U-shape like a horseshoe. This affects the urinary system, which is responsible for filtering blood and producing urine. Because the kidneys are connected, their position and function can be altered, sometimes causing problems with urine flow. People with this condition may experience urinary tract infections, kidney stones, or pain due to obstruction. Many individuals live without symptoms, but the abnormal shape can increase the risk of complications. It is a congenital condition, meaning it is present from birth. Diagnosis often occurs during imaging tests done for other reasons.

Clinical Definition

Horseshoe Kidney is a congenital anomaly characterized by fusion of the lower poles of the kidneys across the midline, typically anterior to the aorta and inferior vena cava, resulting in a U-shaped renal mass. This fusion occurs during embryogenesis due to abnormal migration and rotation of the metanephric blastema. The isthmus connecting the kidneys is composed of functional renal parenchyma or fibrous tissue. This anomaly leads to altered renal position, impaired drainage of the collecting system, and increased risk of hydronephrosis, urinary tract infections, and nephrolithiasis. It is associated with other congenital anomalies such as Turner syndrome and trisomy 18. Despite these risks, many patients remain asymptomatic and the condition is often discovered incidentally on imaging.

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