Table of Contents
Definition of Horseshoe Kidney
The tissue band, called an isthmus, may be fibrous or the same tissue as the kidneys.
In most people who have this anomaly, both kidneys are fully functional.
However, the fusion distorts the normal structure of the kidneys, leading over time to conditions such as HYDRONEPHROSIS (dilation of the renal pelvis), NEPHROLITHIASIS (kidney stones), and VESICOURETERAL REFLUX (backflow of URINE from the BLADDER into the ureters and kidneys).
The BLOOD vessels that supply the horseshoe kidney are often intertwined and anomalous, providing abnormal blood flow to the fused kidney that can affect its functions.
The horseshoe kidney also resides lower in the abdominal cavity, placing it outside the protective enclosure of the rib cage. Horseshoe kidney increases the risk for some types of primary RENAL CANCER.
Symptoms and Diagnosis
Two thirds of people who have horseshoe kidney learn of the anomaly during diagnostic procedures for other health concerns. Doctors diagnose most others in the course of identifying the causes for conditions that affect the kidneys. When symptoms do occur, they generally represent a consequential condition such as nephrolithiasis.
The diagnostic path includes blood and urine tests to assess kidney function. Diagnostic imaging procedures such as COMPUTED TOMOGRAPHY (CT) SCAN or renal ULTRASOUND can provide visual evidence of the fused kidneys. Diagnostic prenatal ultrasound often detects horseshoe kidney in the unborn child.
For the most part horseshoe kidney of itself presents no unusual health risks.
The fused kidneys are prone to the same conditions that affect kidneys in general. Treatment targets any conditions affecting the kidney. The urologist or nephrologist may suggest surgery (nephroplasty) to separate the kidneys and establish normal positioning of the ureters and the blood supply.
Watchful waiting, with routine medical care to monitor kidney function and health, is appropriate for many people who have no symptoms of kidney disease. Researchers do not know what causes horseshoe kidney to occur. One child born with horseshoe kidney does not increase the likelihood that other children will also have the anomaly; the condition appears to be entirely random.