What is Kidney Outlet Stenosis? Symptoms, Findings, Diagnosis and Treatment

Dr. Statement about kidney outlet obstruction from Associate Professor Çağdaş Gökhun Özmerimanı.

Uretero-pelvic junction stenosis-UP Stenosis

The waste materials that come to the kidney are filtered and converted into urine, and this urine is sent to the urinary bladder through the urinary canal (ureter) from the pool (kidney pelvis) located in the middle of the kidney. Stenosis at the junction of the pool and the canal is called renal outlet stenosis-UP stenosis. It is the most common congenital defect of the kidney. As a result, the kidney swells (hydronephrosis) and grows because the urine that should be sent from the canal to the bladder through the kidney cannot be easily evacuated. As this situation continues, a decrease in kidney functions is observed.

Symptoms, Signs and Diagnosis

While routine pregnancy follow-up in the mother's womb, it can be noticed that the baby kidney is enlarged in control ultrasonographies. This finding, which is more noticeable especially in the last 3 months, has become the most common condition in which renal outlet stenosis is diagnosed today.

In children not noticed before birth, urinary tract infections with high fever in infancy, bleeding in the urine, swelling in the abdomen, and renal outlet obstruction may be suspected. The risk of kidney stone formation has also increased in these patients due to the presence of urine that cannot be discharged easily.

In cases of doubt, the first thing to do is radiological evaluation of kidney ultrasonography. Depending on the severity of the exit stenosis, a result in the form of mild, moderate or severe enlargement (hydronephrosis) can be obtained. Renal scintigraphy is required to understand the severity of the stenosis more objectively and to decide what to do in the treatment.

Treatment

Follow-up can be done in mild or moderate strictures. Surgical correction is recommended for those who have severe kidney enlargement and swelling at the time of initial diagnosis, severe prolonged excretion from the kidney into the canal on scintigraphy, and a serious decrease in renal function. The main purpose of surgery is to correct the kidney outlet and the canal junction (pyeloplasty) and to eliminate external pressure, if any. This surgery can be performed by open, laparoscopic or robot-assisted laparoscopic methods.