Reflux nephropathy (RN) is a condition wherein the kidneys are damaged due to chronic backward flow of urine into the kidneys. Unilateral or bilateral reflux can occur, and damage from scarring or atrophy can involve one kidney or both, leading to chronic renal insufficiency. It may be congenital or may occur with acquired conditions that lead to urine flow obstruction. Risk factors for reflux nephropathy include personal history or family history of urine reflux, urinary tract abnormalities, and recurrent urinary tract infections. Treatment of this condition varies with severity of the reflux and damage to the kidney.
This condition is a relatively common form of chronic pyelonephritic scarring. It occurs in young children because of a superimposed urinary tract infection on congenital intrarenal reflux and vesicoureteral reflux. When there is a severe obstruction, vesicoureteral reflux can occasionally cause reflux nephropathy even in the absence of infection. Acquired conditions that lead to urine flow obstruction, and eventually reflux nephropathy if not treated immediately, are bladder stones, bladder outlet obstruction, and neurogenic bladder. Trauma to or swelling of the ureter may also cause reflux nephropathy.
An individual with this condition may be asymptomatic or symptomatic. Symptomatic individuals have symptoms similar to those of a chronic kidney disease or urinary tract infection. The symptoms for chronic kidney disease vary with the degree of severity and are usually nonspecific, but most individuals with this disease have high blood pressure. Urinary tract infection usually produces symptoms of painful urination, blood in the urine, back pain, and urinary frequency, urgency, and hesitancy. Children with recurrent urinary tract infection should be suspected for reflux nephropathy.
Several tests are needed to confirm this condition. These include tests for blood and urine as well as imaging modalities. Blood and urine tests are serum blood urea nitrogen (BUN), serum creatinine, creatinine clearance, urinalysis, and urine culture. Imaging modalities that may be done to demonstrate reflux are ultrasound of the kidneys, simple or delayed cystography, radionuclide cystogram, or voiding cystourethrogram.
Treating conditions that cause urine reflux can prevent reflux nephropathy. Mild reflux can be treated medically. The doctor will prescribe antibiotics to prevent infections and antihypertensive drugs, specifically angiotensin-converting enzyme and angiotensin receptor blockers, to delay kidney damage by controlling blood pressure. Individuals undergoing medical therapy should be monitored regularly and have regular urine cultures and an annual kidney ultrasound. People with severe reflux and those who are unresponsive to medical therapy are treated surgically through ureteral implantation or reconstructive repair.