Urine flows from each kidney through tubes called ureters and into the bladder. When the bladder is full, it squeezes and sends the urine out through the urethra. No urine should flow back into the ureter when the bladder is squeezing. Each ureter has a one-way valve where it enters the bladder that prevents urine from flowing back up the ureter.
But in some people, urine flows back up to the kidney. This is called vesicoureteral reflux.
Over time, the kidneys may be damaged or scarred by this reflux. This is called reflux nephropathy.
Reflux can occur in people whose ureters do not attach properly to the bladder or whose valves do not work well. Children may be born with this problem or may have other birth defects of the urinary system that cause reflux nephropathy.
Reflux nephropathy can occur with other conditions that lead to a blockage of urine flow, including:
Reflux nephropathy is often found when a child is checked for repeated bladder infections. If vesicoureteral reflux is discovered, the child's siblings may also be checked, because reflux can run in families.
Blood pressure may be high, and there may be signs and symptoms of chronic kidney disease.
Blood and urine tests will be done, and may include:
Vesicoureteral reflux is separated into 5 different grades. Simple or mild reflux often falls into grade I or II. The severity of the reflux and amount of damage to the kidney help determine treatment.
Simple, uncomplicated vesicoureteral reflux (called primary reflux) can be treated with:
Antibiotics taken every day to prevent urinary tract infections
Controlling blood pressure is the most important way to slow kidney damage. The health care provider may prescribe medicines to control high blood pressure. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) are often used.
Surgery is usually only used in children who have not responded to medical therapy.
More severe vesicoureteral reflux may need surgery, especially in children who do not respond to medical therapy. Surgery to place the ureter back into the bladder (ureteral reimplantation) can stop reflux nephropathy in some cases.
More severe reflux may need reconstructive surgery. This type of surgery may reduce the number and severity of urinary tract infections.
If needed, people will be treated for chronic kidney disease.
Outcome varies, depending on the severity of the reflux. Some people with reflux nephropathy will not lose kidney function over time, even though their kidneys are damaged. However, kidney damage may be permanent. If only one kidney is involved, the other kidney should keep working normally.
Reflux nephropathy may cause kidney failure in children and adults.
Complications that may result from this condition or its treatment include:
Quickly treating conditions that cause reflux of urine into the kidney may prevent reflux nephropathy.
Bakkaloglu SA, Schaefer F. Diseases of the kidney and urinary tract in children. In: Taal MW, Chertow GM, Marsden PA, Skorecki K, Yu A, Brenner BM, eds. Brenner and Rector's The Kidney. 9th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 75.
Charles Silberberg, DO, private practice specializing in nephrology, affiliated with New York Medical College, Division of Nephrology, Valhalla, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.