Reflux nephropathy is kidney damage (nephropathy) due to urine flowing backward (reflux) from the bladder toward the kidneys; the latter is called

vesicoureteral reflux Vesicoureteral reflux (VUR), also known as vesicoureteric reflux, is a condition in which urine flows retrograde, or backward, from the bladder into one or both ureters and then to the renal calyx or kidneys. Urine normally travels in one directio ...

(VUR). Longstanding VUR can result in small and scarred kidneys during the first five years of life in affected children. The end results of reflux nephropathy can include high blood pressure, excessive protein loss in the urine, and eventually

kidney failure Kidney failure, also known as end-stage kidney disease, is a medical condition in which the kidneys can no longer adequately filter waste products from the blood, functioning at less than 15% of normal levels. Kidney failure is classified as eit ...

. When reflux nephropathy is suspected as a cause of kidney disease, other conditions to consider include chronic

pyelonephritis Pyelonephritis is inflammation of the kidney, typically due to a bacterial infection. Symptoms most often include fever and flank tenderness. Other symptoms may include nausea, burning with urination, and frequent urination. Complications may ...

obstructive uropathy Obstructive uropathy is a structural or functional hindrance of normal urine flow, sometimes leading to renal dysfunction (obstructive nephropathy). It is a very broad term, and does not imply a location or cause. Presentation Symptoms, less lik ...

, and analgesic overuse. The term "reflux nephropathy" was introduced in 1973.

Signs and symptoms

The symptoms of reflux nephropathy are comparable to nephrotic syndrome and infection of the

urinary tract The urinary system, also known as the urinary tract or renal system, consists of the kidneys, ureters, bladder, and the urethra. The purpose of the urinary system is to eliminate waste from the body, regulate blood volume and blood pressure, c ...

, though some individuals may not exhibit any evidence (symptom) of reflux nephropathy.

Cause

The abnormal retrograde flow of urine from the bladder into one or both the ureters leads to vesicoureteral reflux (VUR), which is a direct consequence of incompetent and mislocated ureterovesical valves. Reflux nephropathy is a direct consequence of VUR or other urologic congenital anomalies stemming from chronic high-pressure sterile urine reflux and often leads to recurrent urinary tract infections (UTIs) in the early childhood.Aeddula NR, Baradhi KM. Reflux Nephropathy. pdated 2018 Sep 23 In: StatPearls nternet Treasure Island (FL): StatPearls Publishing; 2018 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526055/

Pathophysiology

The underlying calyces lose their normal concave shape and show clubbing.

Diagnosis

It is diagnosed by micturating

cystography In radiology and urology, a cystography (also known as cystogram) is a procedure used to visualise the urinary bladder. Using a urinary catheter, radiocontrast is instilled in the bladder, and X-ray imaging is performed. Cystography can be used t ...

; scarring can be demonstrated by

ultrasound Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies ...

or DMSA.

Prognosis

Children with reflux nephropathy have higher risk of developing kidney scarring and hypertension in later life.

Treatment

The aim of treatment is to reduce renal scarring. Those children with grade II or worse should receive low dose

prophylactic Preventive healthcare, or prophylaxis, consists of measures taken for the purposes of disease prevention.Hugh R. Leavell and E. Gurney Clark as "the science and art of preventing disease, prolonging life, and promoting physical and mental hea ...

antibiotics (

Nitrofurantoin Nitrofurantoin is an antibacterial medication used to treat urinary tract infections, but it is not as effective for kidney infections. It is taken by mouth. Common side effects include nausea, loss of appetite, diarrhea, and headaches. Rarely ...

trimethoprim Trimethoprim (TMP) is an antibiotic used mainly in the treatment of bladder infections. Other uses include for middle ear infections and travelers' diarrhea. With sulfamethoxazole or dapsone it may be used for ''Pneumocystis'' pneumonia in peo ...

cotrimoxazole Trimethoprim/sulfamethoxazole, sold under the brand name Bactrim among others, is a fixed-dose combination antibiotic medication used to treat a variety of bacterial infections. It consists of one part trimethoprim to five parts sulfamethoxaz ...

, cefalexin in those with CRF). Hypertension should be managed with ACE inhibitor or ARBs. Other treatment modalities include surgery (endoscopic injection of collagen behind the intra-vesical ureter, ureteric re-implantation or lengthening of the submucosal ureteric tunnel) which has its protagonists.

Epidemiology

There is a genetic predisposition, first-degree relatives have a great increase in the chance of VUR. The gene frequency is estimated to be 1:600. The American Academy of Pediatrics recommends that children from 2 to 24 months presenting with a UTI should be investigated for VUR.

References

External links

{{Authority control Nephrology