Vesicoureteral reflux (VUR) can only be diagnosed by a test called a cystogram, in which a catheter is placed through the urethra into the bladder, and the bladder is filled with fluid. This procedure allows doctors to see the reverse flow of urine toward the kidney. There are two types of cystograms: A cystogram is most commonly done in a child who has had a UTI but may also be performed in infants who have hydronephrosis — a condition detected by ultrasound before birth. There are other tests that are sometimes performed in children with VUR including: If a child is suspected of having a urinary tract infection, the urine needs to be sampled using special techniques to avoid contamination and false test results. For younger children and infants, this
usually means passing a catheter into the bladder to obtain a urine sample. In some cases, a bag will be placed on the child to collect urine, although this method has a high rate of false results. In older, toilet-trained children, the child can urinate into a cup. Based on the results of diagnostic vesicoureteral reflux testing, a physician will usually assign a number score for the VUR. Scores range from one to five or
one to three, depending on the type of test performed. The higher the number or score, the more severe the VUR. Children with mild VUR will likely improve over time and are less likely to need surgery. Once VUR resolves itself, it is important for parents to know that their child may still get UTIs. If a child has more severe VUR or gets frequent kidney infections, despite preventative antibiotics, he or she may need surgery to correct the VUR. The severe form of VUR is less likely
to resolve on its own. Ureteral reimplantation surgery is a surgical procedure where the connection between the ureter and the bladder is reconstructed to prevent VUR. Endoscopic treatment is an option for some children who have lower grades of VUR. The procedure is performed on an outpatient basis under general anesthesia. The doctor inserts a small telescope into the bladder through the urethra (the tube
connects the bladder to the outside) and injects a small amount of gel-like material under the opening of the ureter. The injected material partially closes the opening and prevents the urine from going backward toward the kidney. The success rate of this procedure is about 75 percent, and there are very few complications. However, we do not know how long the results will last, since some children can have recurrence of their VUR months or years later. Although there are some advantages to
endoscopic treatment, it is not always the best option. Robot-assisted laparoscopic surgery is performed by inserting small instruments through several tiny incisions in the abdomen. This procedure is normally performed in patients who require repeat surgery for VUR or to treat VUR in adolescents and young adults. The approach is rarely performed in younger children because the success rate for open surgery is better (about 98 percent) and with few
complications. Continued technical improvements in robotic surgical treatment will likely provide good alternatives to open surgery in the future. We have made great progress with robotic-assisted laparoscopic surgery for VUR. The Boston Children’s Hospital Department of Urology team takes a conservative approach to VUR. Most children will
outgrow their VUR on their own, and we give them a chance to do just that.How is vesicoureteral reflux diagnosed?
What are the treatment options for vesicoureteral reflux?
Ureteral reimplantation surgery
Endoscopic treatment
Robotic surgical treatment
How we care for vesicoureteral reflux
Our main goal is to treat vesicoureteral reflux and prevent infections that might affect the kidneys and possibly cause kidney damage. Our specialists provide a comprehensive approach to the management of vesicoureteral reflux from initial diagnosis to treatment and follow-up care.
Citation, DOI & article data
Citation:
Radswiki T, Niknejad M, Rasuli B, et al. Vesicoureteric reflux. Reference article, Radiopaedia.org (Accessed on 25 Nov 2022) //doi.org/10.53347/rID-12737
Vesicoureteric reflux (VUR) is the term for the abnormal flow of urine from the bladder into the upper urinary tract and is typically encountered in young children.
For grading of vesicoureteric reflux, please refer to vesicoureteric reflux grading.
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The incidence of urinary tract infection is 8% in females and 2% in males 2. Among children with urinary tract infections, the incidence of vesicoureteric reflux rises to ~ 25-40%.
Reflux from the bladder into the upper urinary tract predisposes to pyelonephritis by allowing entry of bacteria to the usually sterile upper tract. As such the diagnosis is first suspected after urinary tract infection in a young child.
Vesicoureteric reflux may be an isolated abnormality or associated with other congenital anomalies including:
- congenital obstructive posterior urethral membrane (COPUM) 6
- bulbar urethral obstruction (Cobb collar)
- ureteral partial obstruction
- duplex collecting system
Vesicoureteric reflux is, in the majority of cases, the result of a primary maturation abnormality of the vesicoureteral junction resulting in a short distal ureteric submucosal tunnel. As a result, the normal pinch-cock action of the vesicoureteric junction when bladder pressure increases during micturition is impaired, allowing urine to pass retrogradely up the ureter.
The primary diagnostic procedure for evaluation of vesicoureteric reflux is a voiding cystourethrogram (VCUG), which however requires bladder catheterization and distention of the bladder. This can cause discomfort to the patient but is usually well tolerated if patients are carefully selected and families counseled prior to the study. Patients unsuitable for the catheterization may need to undergo cystoscopy as an alternative. In addition, as it is a fluoroscopic examination it requires ionizing radiation, the dose of which varies greatly depending on the equipment and technique used.
As such other methods for assessing vesicoureteric reflux are being evaluated. These include:
- nuclear medicine studies - such as MAG3, a useful screening tool in older patients
- ultrasound
- MR voiding cystography 3
However, an anatomical assessment of the vesicoureteric junction is needed to help determine the appropriate therapy.
Voiding cystourethrogram (VCUG)Voiding cystourethrogram (also known as micturating cystourethrogram) should be performed after the first well-documented urinary tract infection up to the age of 6 years 3. The reporter should specifically evaluate:
- confirm the presence of reflux with grading where possible
- the occurrence of reflux during micturition or during bladder filling
- presence of associated anatomical anomalies
- length of the ureteric tunnel
- the width of the lower ureter
Routine ultrasound is usually also performed (in addition to voiding cystourethrogram) to assess the renal parenchyma for evidence of scarring or anatomic anomalies.
Additionally, ultrasound has been investigated as a replacement for traditional fluoroscopic voiding cystourethrogram, by assessing the distal ureters during bladder filling, using micro-bubbles 4. Recent evidence has shown that contrast-enhanced voiding urosonography has a performance comparable to conventional voiding cystourethrography in the detection of vesicoureteral reflux but without the radiation exposure of the latter 7.
Nuclear medicineReflux can also be graded, although less precisely, with nuclear cystography. There is no universally accepted grading system for nuclear cystography, with most radiologists simply using the terms mild, moderate, and severe 2.
The advantage of nuclear cystography is the lower radiation dosage, which makes it an excellent tool for screening female patients and for following up patients of both sexes.
Disadvantages of nuclear cystography are difficulty in recognizing important associated bladder disease (e.g. bladder diverticula), difficulty in visualizing the male urethra, and lack of spatial resolution.
MR voiding cystourethrogram protocols are still being developed but have the advantage of not having ionizing radiation and of simultaneously imaging the renal parenchyma 3.
Treatment and prognosis
Significant vesicoureteral reflux, if untreated, may lead to recurrent urinary tract infections, renal scarring, and eventually renal failure (reflux nephropathy).
Low-grade reflux may be treated by prophylactic antibiotic treatment.
Surgical reimplantation for the treatment of higher grades of reflux is aimed at reducing the incidence of reflux nephropathy.
Endoscopic treatment, performed by injection of a bulking agent (e.g. Deflux™) at the ureterovesical junction, may be used and is variably effective in preventing sequelae of reflux 5.