Duplex kidney, also called duplicated ureters, is a problem with the urinary tract where there are two ureters draining urine from a single kidney. It’s more common in females than males and it’s an unpreventable birth defect. There are surgeries available to fix the problem, but most issues simply resolve on their own. Treatment is rarely needed.
Duplex kidney, also known as duplicated ureters or duplicated collecting system, is the most common birth defect related to the urinary tract. This occurs due to an incomplete fusion of the upper and lower pole of the kidney which creates two separate drainage systems from the kidney.
Most people do not need treatment.
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Ureters are long, narrow tubes that drain urine from your kidneys to your bladder. Normally one ureter leads from each kidney to your bladder. In the case of duplicated systems, two ureters drain a single kidney. One ureter drains the upper pole of your kidney and the other drains the lower pole. This condition may affect one or both kidneys.
Duplex kidney can take on one of two forms:
About 0.7% of the healthy adult population and 2% to 4% of patients with urinary tract issues have duplicated ureters. Incomplete duplication is three times more common than complete duplication, which is estimated to appear in about one in every 500 people.
Both boys and girls are affected, but the condition is more common in females.
Duplex kidney is a result of errors in cell division that occur during the development of the fetus inside the uterus. There is no evidence that suggests anything during pregnancy causes the defect. However, there is evidence to show that the condition can be passed from parent to child. If one parent has a duplex kidney, the child has a 50-50 chance of also being born with this condition.
As long as your duplicated ureters drain normally into your bladder they should not cause any symptoms. If symptoms do occur, it is usually in the case of complete duplicated ureters.
A duplex kidney can occur with other abnormalities of your urinary system. One common abnormality is an ureterocele, which occurs when the end of the ureter does not develop properly, and urine flow is obstructed. This results in a balloon-like swelling as urine builds up at the point where the ureter and bladder connect. In addition, urine can reflux back toward the kidney through the second ureter, which often has a weak valve because it joins the bladder in an abnormal location.
A number of symptoms can occur when one of the ureters is ectopic, which means it drains to somewhere other than the bladder. Symptoms of an ectopic ureter include:
The duplication occurs during embryological development and is present at birth.
Duplicated ureters are usually found during childhood, due to the presentation of UTIs or incontinence. Sometimes they are not discovered until adulthood as symptoms may resemble other health problems, making it difficult to arrive quickly at a correct diagnosis.
A number of tests can help find duplicated ureters:
Most people do not need treatment.
If needed, treatments include:
There is no known way to prevent a duplex kidney, as it results from a birth defect. However, the previously discussed surgeries can be performed to relieve symptoms and protect the kidneys from damage.
The amount of recovery time needed after surgery depends on the procedure performed and the age of the patient. Children usually need one to two days in the hospital for recovery, then continued rest at home for one to two weeks.
An ultrasound of your kidney is usually done four to six weeks after surgery.
No long-term problems with kidney function or sexual function will result from treatment.
Typically there are no symptoms of duplex kidney. However, if you have another condition related to the urinary tract, or if a ureter is ectopic, then your quality of life might be effected. You may need to have tests done and procedures performed. Fortunately, these conditions aren’t life-threatening and the treatments are effective.
There are no at-home treatments for duplex kidney. However, if you or your child have surgery, be sure to follow all of your healthcare providers’ instructions exactly.
A note from Cleveland Clinic
Although duplex kidney (duplicated ureters) isn’t a life-threatening condition, or one that typically causes symptoms, it may require treatment. Duplex kidney can happen alongside a number of other conditions related to the urinary tract. Make sure you take those conditions, like incontinence and urinary tract infections, seriously – get them treated right away. You may not even know you have duplex kidney until you have a different condition. Be sure to connect with your healthcare providers and follow their instructions.
Last reviewed by a Cleveland Clinic medical professional on 12/04/2020.
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