Antenatal hydronephrosis, which translates to "water in the kidney," refers to a condition in which the renal pelvis expands, usually due to an obstruction in the normal flow of urine through the kidney, leading to urine accumulation. Kidney expansion is a common finding (around 2%-4%) in prenatal ultrasound examinations. A few decades ago, kidney expansion couldn't be detected before the appearance of secondary symptoms like lower back pain, urinary infection, or kidney insufficiency. Nowadays, modern imaging technologies allow for the diagnosis of kidney expansion and even the identification of the underlying causes in the early stages of the disease. Thanks to early diagnosis, in most cases, corrective measures can be taken before irreversible deterioration in kidney function occurs.
Common causes of kidney expansion in fetuses include dilation in the renal pelvis outlet and dilation in the ureter's entry point into the bladder. In the latter case, the ultrasound examination will also reveal ureteral dilation. Kidney expansion can also occur due to vesicoureteral reflux, where urine flows back from the bladder into the kidney. Another, although less common, cause is posterior urethral valves in boys.
In most cases, surgical intervention will not be required, and the child will be placed under observation only. Monitoring is of great importance in the therapeutic process, as it helps identify problems or complications in advance that might require a more aggressive treatment approach. Even in cases of surgical intervention, it is a procedure without complications, yielding positive outcomes.
The Pediatric Urology Department at Shaare Zedek Medical Center was among the pioneers worldwide to adopt a conservative approach in the management of varying degrees of prenatal kidney expansion, rather than surgical intervention in all cases.
Today, this is the accepted approach in Western medicine for treating children with prenatal kidney expansion. The department's physicians are an integral part of the multidisciplinary team that supports parents from the moment of diagnosis through birth, final diagnosis, and performing surgery if necessary.
The surgery is minimally invasive for removing the blockage or endoscopic surgery for repairing vesicoureteral reflux. The department's physicians specialize in both techniques, yielding good results with no scars and a short healing time before returning to normal activities.