Urinary tract infection is not an expected situation in a normal healthy, cleanly cared child.  For this reason, we, physicians, especially if there is a child with a febrile urinary tract infection, evaluate by ultrasonography, and if an unexpected result is obtained, we go further and try to reveal the underlying cause.  The underlying cause may be the upward flow of urine in the bladder.  This reflux may occur during urinary tract infection, or it may give us a clue in advance with the findings of the examinations made while the baby is still in the mother’s uterine.
I wrote about vesico-ureteral reflux, which is called “VUR” in children in this month’s Pediatric Surgeon’s journal.  
If there is urinary reflux, the bacterial urine that may occur in the bladder may escape to the upper kidneys and cause febrile kidney infections, followed by the development of scar tissue in the kidney, then hypertension and chronic kidney disease.  For these reasons, we, physicians, pediatric surgeons, nephrologists and pediatric urologists attach special importance to this pathology.
So what causes vesicoureteral reflux?  Why does the urine accumulated in the bladder go up to the kidneys?
Normally, the ureter, which carries urine from the kidney to the bladder, opens inside the bladder after a little progress in the its wall.  Thus, when the bladder fills with urine and starts to swell, the duct part in the bladder wall begins to squeeze between the bladder muscles and this prevents the reflux of the accumulated urine upwards.  The breakdown of this mechanism causes upward reflux.
How can the mechanism preventing this upward leakage be broken?
Either the length of the urethra within the bladder wall is too short (which is the group that heals spontaneously if the intra-wall part of the ureter lengthens over time), either the duct opens into the bladder through a wrong place, or the pressure is so high inside the bladder that the upward leakage prevention mechanism is not sufficient.
How can the pressure in the bladder increase?  
It can either be an anatomical defect, for example posterior urethral valve; or accompanied by functional impairment of the bladder, eg. bladder bowel dysfunction.  In other words, there is a blockage at the outlet of the bag, so the bladder contracts but cannot empty, the pressure inside increases and the urine refluxes upwards.  Or the bladder does not work properly, for example, the muscles of the sac contract to empty the bladder, but the muscles at the opening of the sac do not relax in a coordinated manner, thus increasing intra-vesical pressure and causing upward leakage.
Urinary reflux can be detected in almost 15% of babies with enlargement of the kidneys in the uterine, and in approximately 30-40% of children with febrile urinary tract infection.  While the majority of those detected in the uterine are boys, the majority of older children are girls.  But the most important thing for us is that this problem can be found in 27% of siblings of children with reflux and in 35% of children of parents with reflux.  These findings suggest that there is an underlying genetic cause.
With all this told, if we suspect urinary reflux, we need to do a test called voiding cystourethrography to make the diagnosis.  We insert a catheter, fill the bladder with medicated water and see if there is a passage towards the kidneys.  As a result of this test, we can obtain a lot of data such as the capacity of the bladder, its shape, the degree of urinary reflux, the appearance of the urinary tract during urination, whether there is a problem at the exit of the bladder, whether the bladder is fully emptied or not, etc.  There are other methods that can give less radiation such as scintigraphy or water ultrasonography, but we do not prefer them because they do not show the anatomy as well as this test, we only use them sometimes in follow-ups.
If we detect urinary reflux in our patient, we definitely evaluate the child’s growth by measuring his height, weight and blood pressure.  We try to understand the possibility of an accompanying bladder and bowel dysfunction by questioning complaints such as urinary frequency, urinary incontinence, constipation, and poop incontinence.  We perform the clinical evaluation of the kidney with findings such as urine and blood tests, protein in the urine, blood urea and creatinine values.  With the scintigraphic examinations of the kidney, we can understand whether there is scar tissue in the kidney and evaluate its functions.
Also, since we know that the siblings of children with urinary reflux may also have the same problem, they should also be tested in order to see if they have the same issue. We do not ignore the possibility of having a sibling, especially if symptoms of bladder bowel dysfunction or urinary tract infections are described in siblings under the age of five, or if we feel that we are not getting enough information from the parents.
After collecting all the data I have explained, we discuss our patient in our “pediatric nephrology-urology” council, which is attended by pediatric nephrologists, pediatric surgeons, pediatric urologists, pediatric radiologists and nuclear medicine specialists, and we decide what path to follow.
That’s enough for now.  We finished another course in the Pediatric Surgeon’s Journal.  I will tell you how we treat a child with urinary reflux and information such as the course, progression and consequences of this disease in the next journal.
Please click if you want to watch the video, follow us on instagram, and stay happy.
Prof.  Dr.  Egemen Eroglu
May 2022