Vesicoureteral reflux
Encyclopedia
Vesicoureteral reflux is an abnormal movement of urine
from the bladder
into ureter
s or kidney
s. Urine normally travels from the kidneys via the ureters to the bladder. In vesicoureteral reflux the direction of urine flow is reversed (retrograde).
, an abnormal widening of the ureter
or with a urinary tract infection
or acute pyelonephritis
. Symptoms such as painful urination or renal colic
/flank pain are not symptoms associated with vesicoureteral reflux.
Newborns may be lethargic with faltering growth, while infants and young children typically present with pyrexia, dysuria
, frequent urination
, malodorous urine and GIT
symptoms, but only when urinary tract infection is present as the initial presentation of VUR.
Hardikar syndrome can include Vesicoureteral reflux, Hydronephrosis
, cleft lip and palate, Intestinal obstruction and other symptoms.
Anatomical: Posterior urethral valves; urethral or meatal stenosis.
These causes are treated surgically when possible.
Functional: Bladder instability, neurogenic bladder and non-neurogenic neurogenic bladder
Urinary tract infections may cause reflux due to the elevated pressures associated with inflammation.
Resolution of functional VUR will usually occur if the precipitating cause is treated and resolved. Medical and/or surgical treatment may be indicated.
In children under the age of 1 year with a urinary tract infection, 70% will have VUR. This number decreases to 15% by the age of 12.
The younger the age of the patient and the lower the grade at presentation the higher the chance of spontaneous resolution. Most (approx. 85%) of grade I & II cases of VUR will resolve spontaneously. Approximately 50% of grade III cases and a lower percentage of higher grades will also resolve spontaneously.
An abdominal ultrasound might suggest the presence of VUR if ureteral dilatation is present; however, in many circumstances of VUR of low to moderate severity, the sonogram may be completely normal, thus providing insufficient utility as a single diagnostic test in the evaluation of children suspected of having VUR, such as those presenting with prenatal hydronephrosis
or urinary tract infection
(UTI). VCUG is the method of choice for grading and initial workup, while RNC is preferred for subsequent evaluations as there is less exposure to radiation. A high index of suspicion should be attached to any case a where a child presents with a urinary tract infection, and anatomical causes should be excluded. A VCUG and abdominal ultrasound should be performed in these cases
Early diagnosis in children is crucial as studies have shown that the children with VUR who present with a UTI and associated acute pyelonephritis are more likely to develop permanent renal cortical scarring than those children without VUR, with an odds ratio of 2.8. Thus VUR not only increases the frequency of UTI's, but also the risk of damage to upper urinary structures.
and hyaluronic acid. Both substances are well-known from previous uses in medicine. Both materials are also biocompatible, which means that they do not cause significant reactions within the body. In fact, hyaluronic acid is produced and found naturally within the body.
After 2 months the following antibiotics are suitable:
Urine cultures are performed 3 monthly to exclude breakthrough infection. Annual radiological investigations are likewise indicated. Good perineal hygiene, and timed and double voiding are also important aspects of medical treatment. Bladder dysfunction is treated with the administration of anticholinergic
s.
There are three types of surgical procedure available for the treatment of VUR: endoscopic (STING/HIT procedures); laparoscopic; and open procedures (Cohen procedure, Leadbetter-Politano procedure).
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
from the bladder
Urinary bladder
The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. A hollow muscular, and distensible organ, the bladder sits on the pelvic floor...
into ureter
Ureter
In human anatomy, the ureters are muscular tubes that propel urine from the kidneys to the urinary bladder. In the adult, the ureters are usually long and ~3-4 mm in diameter....
s or kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
s. Urine normally travels from the kidneys via the ureters to the bladder. In vesicoureteral reflux the direction of urine flow is reversed (retrograde).
Symptoms
Vesicoureteral reflux may present before birth as prenatal hydronephrosisHydronephrosis
Hydronephrosis is distension and dilation of the renal pelvis calyces, usually caused by obstruction of the free flow of urine from the kidney, leading to progressive atrophy of the kidney...
, an abnormal widening of the ureter
Ureter
In human anatomy, the ureters are muscular tubes that propel urine from the kidneys to the urinary bladder. In the adult, the ureters are usually long and ~3-4 mm in diameter....
or with a urinary tract infection
Urinary tract infection
A urinary tract infection is a bacterial infection that affects any part of the urinary tract. Symptoms include frequent feeling and/or need to urinate, pain during urination, and cloudy urine. The main causal agent is Escherichia coli...
or acute pyelonephritis
Pyelonephritis
Pyelonephritis is an ascending urinary tract infection that has reached the pyelum or pelvis of the kidney. It is a form of nephritis that is also referred to as pyelitis...
. Symptoms such as painful urination or renal colic
Renal colic
Renal colic is a type of abdominal pain commonly caused by kidney stones.-Presentation:The pain typically begins in the abdomen and often radiates to the hypochondrium or the groin. The pain is often colicky due to ureteric peristalsis, but may be constant...
/flank pain are not symptoms associated with vesicoureteral reflux.
Newborns may be lethargic with faltering growth, while infants and young children typically present with pyrexia, dysuria
Dysuria
In medicine, specifically urology, dysuria refers to painful urination.Difficult urination is also sometimes described as dysuria.It is one of a constellation of irritative bladder symptoms, which includes urinary frequency and haematuria....
, frequent urination
Polyuria
Polyuria is a condition usually defined as excessive or abnormally large production or passage of urine . Frequent urination is sometimes included by definition, but is nonetheless usually an accompanying symptom...
, malodorous urine and GIT
Gastrointestinal tract
The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....
symptoms, but only when urinary tract infection is present as the initial presentation of VUR.
Causes
In healthy individuals the ureters enter the urinary bladder obliquely and run submucosally for some distance. This, in addition to the ureter's muscular attachments, helps secure and support them posteriorly. Together these features produce a valvelike effect that occludes the ureteric opening during storage and voiding of urine. In people with VUR, failure of this mechanism occurs, with resultant retrograde flow of urine.Hardikar syndrome can include Vesicoureteral reflux, Hydronephrosis
Hydronephrosis
Hydronephrosis is distension and dilation of the renal pelvis calyces, usually caused by obstruction of the free flow of urine from the kidney, leading to progressive atrophy of the kidney...
, cleft lip and palate, Intestinal obstruction and other symptoms.
Primary VUR
Insufficient submucosal length of the ureter relative to its diameter causes inadequacy of the valvular mechanism. This is precipitated by a congenital defect/lack of longitudinal muscle of the intravesical ureter resulting in an ureterovesicular junction (UVJ) anomaly.Secondary VUR
In this category the valvular mechanism is intact and healthy to start with but becomes overwhelmed by raised vesicular pressures associated with obstruction, which distorts the ureterovesical junction. The obstructions may be anatomical or functional. Secondary VUR can be further divided into anatomical and functional groups as follows:Anatomical: Posterior urethral valves; urethral or meatal stenosis.
These causes are treated surgically when possible.
Functional: Bladder instability, neurogenic bladder and non-neurogenic neurogenic bladder
Urinary tract infections may cause reflux due to the elevated pressures associated with inflammation.
Resolution of functional VUR will usually occur if the precipitating cause is treated and resolved. Medical and/or surgical treatment may be indicated.
Prevalence
It has been estimated that VUR is present in more than 10% of the population. In children without urinary tract infections 17.2-18.5% have VUR, whereas in those with urinary tract infections the incidence may be as high as 70%.Age
Younger children are more prone to VUR because of the relative shortness of the submucosal ureters. This susceptibility decreases with age as the length of the ureters increases as the children grow.In children under the age of 1 year with a urinary tract infection, 70% will have VUR. This number decreases to 15% by the age of 12.
Sex
Although VUR is more common in males antenatally, in later life there is a definite female preponderance with 85% of cases being female.International Classification of Vesicoureteral Reflux
- Grade I – reflux into non-dilated ureter
- Grade II – reflux into the renal pelvis and calyces without dilatation
- Grade III – mild/moderate dilatation of the ureter, renal pelvis and calyces with minimal blunting of the fornices
- Grade IV – dilation of the renal pelvis and calyces with moderate ureteral tortuosity
- Grade V – gross dilatation of the ureter, pelvis and calyces; ureteral tortuosity; loss of papillary impressions
The younger the age of the patient and the lower the grade at presentation the higher the chance of spontaneous resolution. Most (approx. 85%) of grade I & II cases of VUR will resolve spontaneously. Approximately 50% of grade III cases and a lower percentage of higher grades will also resolve spontaneously.
Diagnosis
The following procedures may be used to diagnose VUR:- Nuclear cystogram (RNC)
- Fluoroscopic voiding cystourethrogramVoiding cystourethrogramIn urology, a voiding cystourethrogram , also micturating cystourethrogram , is a technique for watching a person's urethra and urinary bladder while the person urinates . The technique consists of catheterizing the person in order to fill the bladder with a radiocontrast agent, typically cystografin...
(VCUG) - Ultrasonic cystography
- Abdominal ultrasound
An abdominal ultrasound might suggest the presence of VUR if ureteral dilatation is present; however, in many circumstances of VUR of low to moderate severity, the sonogram may be completely normal, thus providing insufficient utility as a single diagnostic test in the evaluation of children suspected of having VUR, such as those presenting with prenatal hydronephrosis
Hydronephrosis
Hydronephrosis is distension and dilation of the renal pelvis calyces, usually caused by obstruction of the free flow of urine from the kidney, leading to progressive atrophy of the kidney...
or urinary tract infection
Urinary tract infection
A urinary tract infection is a bacterial infection that affects any part of the urinary tract. Symptoms include frequent feeling and/or need to urinate, pain during urination, and cloudy urine. The main causal agent is Escherichia coli...
(UTI). VCUG is the method of choice for grading and initial workup, while RNC is preferred for subsequent evaluations as there is less exposure to radiation. A high index of suspicion should be attached to any case a where a child presents with a urinary tract infection, and anatomical causes should be excluded. A VCUG and abdominal ultrasound should be performed in these cases
Early diagnosis in children is crucial as studies have shown that the children with VUR who present with a UTI and associated acute pyelonephritis are more likely to develop permanent renal cortical scarring than those children without VUR, with an odds ratio of 2.8. Thus VUR not only increases the frequency of UTI's, but also the risk of damage to upper urinary structures.
Treatment
Medical treatment is the preferred mode of management, but surgical interventions may be necessary. Medical management is recommended in children with Grade I-III VUR as most cases will resolve spontaneously. A trial of medical treatment is indicated in patients with Grade IV VUR especially in younger patients or those with unilateral disease. Of the patients with Grade V VUR only infants are trialed on a medical approach before surgery is indicated, in older patients surgery is the only option.Endoscopic Injection
Deflux is a gel that is used in endoscopic injections to treat Vesicoureteral Reflux. It is the material that the surgeon injects around the ureteral opening to create a valve function and stop urine from flowing back up the ureter. Deflux consists of two types of sugar-based molecules called dextranomerDextranomer
Dextranomer is a cicatrizant used in dressings for wound healing, and in pharmaceutical products to treat fecal incontinence. It consists of dextran polymer chains cross-linked into a three-dimensional network....
and hyaluronic acid. Both substances are well-known from previous uses in medicine. Both materials are also biocompatible, which means that they do not cause significant reactions within the body. In fact, hyaluronic acid is produced and found naturally within the body.
Medical Treatment
Medical treatment entails low dose antibiotic prophylaxis until resolution of VUR occurs. Antibiotics are administered nightly at half the normal therapeutic dose. The specific antibiotics used differ with the age of the patient and include:- AmoxicillinAmoxicillinAmoxicillin , formerly amoxycillin , and abbreviated amox, is a moderate-spectrum, bacteriolytic, β-lactam antibiotic used to treat bacterial infections caused by susceptible microorganisms. It is usually the drug of choice within the class because it is better absorbed, following oral...
or ampicillinAmpicillinAmpicillin is a beta-lactam antibiotic that has been used extensively to treat bacterial infections since 1961. Until the introduction of ampicillin by the British company Beecham, penicillin therapies had only been effective against Gram-positive organisms such as staphylococci and streptococci...
- infants younger than 6 weeks - Trimethoprim-sulfamethoxazole (co-trimoxazole) - 6 weeks to 2 months
After 2 months the following antibiotics are suitable:
- NitrofurantoinNitrofurantoinNitrofurantoin is an antibiotic which is marketed under the following brand names; Furadantin, Macrobid, Macrodantin, Nitrofur Mac, Nitro Macro, Nifty-SR, Martifur-MR, Martifur-100 , Urantoin, and Uvamin . It is usually used in treating urinary tract infection...
{5–7 mg/kg/24hrs} - Nalidixic acidNalidixic acidNalidixic acid is the first of the synthetic quinolone antibiotics...
- Bactrim
- TrimethoprimTrimethoprimTrimethoprim is a bacteriostatic antibiotic mainly used in the prophylaxis and treatment of urinary tract infections.It belongs to the class of chemotherapeutic agents known as dihydrofolate reductase inhibitors...
- CephalosporinCephalosporinThe cephalosporins are a class of β-lactam antibiotics originally derived from Acremonium, which was previously known as "Cephalosporium".Together with cephamycins they constitute a subgroup of β-lactam antibiotics called cephems.-Medical use:...
s
Urine cultures are performed 3 monthly to exclude breakthrough infection. Annual radiological investigations are likewise indicated. Good perineal hygiene, and timed and double voiding are also important aspects of medical treatment. Bladder dysfunction is treated with the administration of anticholinergic
Anticholinergic
An anticholinergic agent is a substance that blocks the neurotransmitter acetylcholine in the central and the peripheral nervous system. An example of an anticholinergic is dicycloverine, and the classic example is atropine....
s.
Surgical Management
A surgical approach is necessary in cases where a breakthrough infection results despite prophylaxis, or there is non-compliance with the prophylaxis. Similarly if the VUR is severe (Grade IV & V), there are pyelonephritic changes or congenital abnormalities. Other reasons necessitating surgical intervention are failure of renal growth, formation of new scars, renal deterioration and VUR in girls approaching puberty.There are three types of surgical procedure available for the treatment of VUR: endoscopic (STING/HIT procedures); laparoscopic; and open procedures (Cohen procedure, Leadbetter-Politano procedure).