The horseshoe kidney is a congenital malformation: your two kidneys are fused together instead of lying apart. A horseshoe kidney is not a disease, but an anatomical peculiarity.
Usually, a person’s two kidneys are located to the right and left of the spine outside the abdominal cavity. Both organs show the typical bean shape. The right one is usually a little smaller and lighter than the left one. In a horseshoe kidney, the two lower poles of the kidneys are fused together. This malformation is congenital.
The Causes of a Horseshoe Kidney:
The horseshoe kidney develops in the embryonic stage, when the two kidney systems grow together in the first weeks of pregnancy instead of developing separately. If you look at the kidney in cross-section, you can see a U-shaped arch at the point of the adhesions, which is reminiscent of a horseshoe. The horseshoe kidney lies a little deeper on the lumbar spine than normal and is also “the wrong way”, which is why the renal pelvis faces forward towards the abdomen.
The horseshoe kidney is more common in connection with certain genetic diseases:
- Trisomy 18 (Edwards Syndrome): Chromosome 18 is present three times instead of twice. The mistake happens randomly in the development of the embryo. A higher age of the mother is a risk factor. Organ malformations of the heart, brain, kidneys and growth disorders are among other things the result.
- Turner syndrome: The congenital disease only affects women who have only one functioning X chromosome instead of two sex chromosomes (XX). Organ malformations, infertility, short stature are some of the consequences.
Symptoms are often Absent:
Many people with a horseshoe kidney have no symptoms. If anything, your doctor may discover the abnormality by chance during an ultrasound scan. If you have no symptoms, treatment is not necessary.
However, the position of the horseshoe kidney in the abdomen can mean that your ureter is kinked. Then the urine from the kidney may not flow freely and build up. This promotes urinary tract infections or the development of kidney stones. If you notice any of the following changes, you should see a doctor soon:
- The amount of urine decreases.
- The smell changes.
- Blood, grit, or stones can be found in your urine.
- You feel pain in your lower back or in the groin area.
- You suddenly develop a fever.
Diagnosis is Often Made by Chance:
- If your doctor does an ultrasound scan of your abdomen, they can quickly see the shape and location of the kidney – and any horseshoe kidney.
- Urine and blood tests provide information about kidney function and any inflammation.
- Magnetic resonance or computed tomography provide more detailed information about the malformation .
- Excretory urography (AUG) can determine the extent of impaired urine outflow from the bladder or urine backflow from the bladder into the kidney.
Therapy is Usually not Necessary:
If the horseshoe kidney is not causing you any symptoms, you do not need to seek treatment.
If you suffer from bladder infections due to the anatomical peculiarities, you should have this treated, for example with antibiotics. In order to prevent the further development of kidney stones, an operation can be useful, which helps the urine to drain better. People with a horseshoe kidney are also slightly more likely to develop kidney tumors, which also require treatment.