Hydronephrosis is a condition that affects the urinary tract. This consists of an increasing volume of the renal pelvis, chalices and often the kidneys, following an accumulation of normal, uninfected urine. The renal pelvis is a funnel-shaped tank that collects the urine from the kidney before discharging it into the bladder via the urethra. Kidney chalices lie just above the pelvis. The causes of hydronephrosis are many, mainly the existence of an obstruction to the normal flow of urine, or when the renal pelvis weakens. In most cases, hydronephrosis is a condition found in children, as part of a malformation of the urinary tract defined by an abnormality of the implementation of the ureter in the renal pelvis.
Symptoms of hydronephrosis can be represented by:
- lower back pain;
- frequent urinary tract infections;
- rarely, a palpable mass in the abdomen next to a kidney.
However, in most cases, hydronephrosis is discovered before birth.
The diagnosis of hydronephrosis is through an ultrasound that shows the size of the pelvis, chalices and kidneys. This exam can also detect a possible obstruction to the flow of urine, but most of the time, it highlights a morphological abnormality and, most often, a pyelo-ureteral junction will found. Hydronephrosis is also often discovered before birth, during an ultrasonic monitoring of pregnancy. In this context, further tests are performed like a cystography in which X-rays of the urinary tract are taken after the injection of a contrast, but also renal scintigraphy to assess kidney functions.
Hydronephrosis treatment depends on the cause. This may include removing the cause of the obstruction. If the condition is congenital, the operation will aim to correct the anatomical defect.
Hydronephrosis is usually due to a congenital anatomical anomaly, prevention is difficult, but a diagnosis before birth allows for early treatment.