Ureteral Stenosis

By | June 10, 2022

A ureteral stenosis is a congenital or acquired narrowing of the renal pelvis transition in the direction of the ureter. Stenosis is particularly common in childhood.

What is ureteral stenosis?

There is talk of a ureteral stenosis when there is a constriction at the transition from the renal pelvis to the ureter (ureter). The constriction results in an accumulation of urine and the widening of the renal pelvis ( hydronephrosis ). The ureteral outlet stenosis is also called renal pelvic outlet narrowing.

In most cases, the ureteral stenosis is already congenital and shows up in babies or small children. In some cases, however, narrowing in adulthood is also possible. This can lead to repeated stenoses. For cryptitis explained, please visit psyknowhow.com.

With a proportion of around 80 percent, ureteral stenosis is the most common reason for renal pelvic ectasia in old age. In newborns, the frequency is two to eight children in 10,000 babies. In adults, on the other hand, the frequency of ureteral stenosis is less easy to determine because the incidence rates of the examined person vary greatly.

In most cases, the ureteral stenosis occurs on the left side of the body. It is present on both sides in 10 to 40 percent of all patients. Males suffer more often from a narrowing of the renal pelvis than females.


There are two possible causes of ureteral stenosis. In most cases, the narrowing is congenital, which makes it difficult for urine to flow out of the kidney. The congenital form, which is called the primary form in medicine, can already be recognized by examinations during pregnancy.

Sometimes, however, it first becomes apparent through pain that takes a colicky course or inflammation of the renal pelvis. If the ureteral stenosis is acquired in the course of life, which doctors classify as a secondary form, this is due to a blood vessel that runs atypically. This in turn results in more difficult urine drainage because the ureter is narrowed. Due to the outflow obstruction, the urine eventually accumulates within the renal pelvis. This is expanding more and more.

A ureteral stenosis is differentiated into an intrinsic (internal) or an extrinsic (external) form. A combination of both forms is also possible. The intrinsic form is mostly congenital and is triggered by functional or anatomical disorders. The reason for this is insufficient retubularization of the ureter segment between the 10th and 12th week of pregnancy.

An imbalance in growth factors is suspected, which has a negative effect on smooth muscle development and segmental peristalsis. In rare cases, ureteral polyps or ureteral valves can also be responsible for a ureteral stenosis. An extrinsic narrowing of the renal pelvis is caused by arterial or venous blood vessels crossing the course of the ureter in a disruptive manner. Other possible causes are tumors, post-traumatic sequelae or retroperitoneal inflammation.

Symptoms, Ailments & Signs

It is not uncommon for there to be no symptoms of ureteral stenosis if the narrowing has already been detected by a prenatal ultrasound examination, which is the case in around 60 percent of all children. In older children, pain in the flanks can sometimes occur. The accumulation of urine in the renal pelvis is responsible for this.

The pain is particularly evident after an extensive intake of fluids. Due to the outflow obstruction there is also an increased risk of urinary tract infections. In some cases, an abdominal tumor can be felt. Symptoms such as colicky flank pain, back pain or pain in the upper abdomen are also possible in adulthood. If the ureteral stenosis persists over a longer period of time, this can lead to secondary high blood pressure, which is associated with a high plasma renin level.

Diagnosis & course of disease

In most cases, ureteral stenosis is diagnosed during pregnancy. The kidneys are checked by sonography (ultrasound examination). The doctor usually notices a unilateral enlargement of the renal pelvis. Furthermore, the parenchyma (kidney tissue) can be well assessed using an ultrasound examination.

Another important diagnostic method is scintigraphy. With this method, the kidney function and the drainage conditions of the urinary tract can be checked. The ureteral stenosis usually takes on different dimensions, on which the course of the disease depends. Sometimes there is a risk of a drop in kidney function. In such cases, an operation is performed to correct the narrowing.


In many cases, the ureteral stenosis does not directly lead to complaints or symptoms. For this reason, this disease is in many cases only discovered relatively late in regular examinations and for this reason cannot be treated early. Those affected usually suffer from a high risk of urinary tract infections.

These can be associated with pain when urinating. It is also not uncommon for severe pain in the flanks to occur with ureteral stenosis. This pain also spreads to the back and can lead to restricted movement. Pain in the upper abdomen or in the stomach can also occur.

Furthermore, the ureteral stenosis leads to high blood pressure, which in the worst case can lead to a heart attack. The person concerned can also die. The treatment of ureteral stenosis usually depends on the symptoms. In the case of infections, they are treated with antibiotics.

In many cases, however, surgical interventions are necessary to alleviate the symptoms. There are no particular complications. It may also be necessary to completely remove a kidney. It may also reduce the patient’s life expectancy.

When should you go to the doctor?

Since ureteral stenosis cannot heal itself, the affected person is dependent on medical examination and treatment. This is the only way to avoid further complaints, complications or a further deterioration of the symptoms. As soon as the first signs or symptoms of the disease appear, the affected person should contact a doctor.

In most cases, the ureteral stenosis is discovered by a routine ultrasound examination. In some cases, pain in the flanks can also indicate the disease. If this pain occurs over a longer period of time, a doctor should be contacted. High blood pressure, which occurs for no particular reason, or severe pain in the back and upper abdomen can also indicate this disease. If these symptoms do not go away on their own, a doctor should also be contacted.

In most cases, the ureteral stenosis can be diagnosed and treated by a urologist.

Treatment & Therapy

It is not always necessary to perform an operation in the case of a ureteral stenosis. However, if symptoms such as repeated infections appear, surgical intervention cannot be avoided. The same applies if the outflow of urine is less than 40 percent.

A flap is used as part of the operation on the pyeloureteral transition, which is used, among other things, to correct a high exit. An alternative is the complete severing and reconstruction of the renal pelvis including the ureteral outlet. If necessary, the newly created renal pelvis and the connected ureteral connection can be relieved using a catheter.

In recent years, medicine has also increasingly used minimally invasive techniques to correct ureteral stenosis. During the operation, the surgeon usually cuts off the ureter, the constriction and a section of the renal pelvis. He then sews the ureter back into the renal pelvis and closes it. If the kidney function on the affected side of the body is less than ten percent, it is sometimes necessary to remove the kidney.


A ureteral stenosis can hardly be prevented. In most cases it is already congenital.


Follow-up treatment is required if the ureteric stenosis has been treated surgically. After the operation, the affected child usually has to stay in the hospital for about four to six days. Up to a week after removing the splint, the child is advised to be released from school or daycare.

It is also considered sensible for the child to refrain from physical education and other sporting activities for up to four weeks. After the control examination by sonography (ultrasound examination) and the removal of any catheters that may have been inserted, the child can return home and recover there.

About six weeks after the operation, a scintigraphy takes place for further control. In this nuclear medicine procedure, the doctor checks whether the urine is draining better from the renal pelvis. The pediatrician usually takes care of the further follow-up treatment. Whether further check-ups are necessary usually depends on the individual findings of the child.

If necessary, outpatient examinations that serve as additional controls are carried out on a regular basis. The focus is on the growth of the kidney and the outflow conditions. Until the child has completed its growth, the further follow-up examinations are carried out at longer intervals. If the child still suffers from pain after the surgical procedure, this is treated with analgesics.

You can do that yourself

Stenosis of the ureter must always be treated. Mild symptoms may require symptomatic therapy with painkillers, the intake of which should be carefully monitored. In addition, the renal pelvis must be constantly monitored. Parents must pay attention to symptoms in the child that indicate a deterioration in the state of health and, if necessary, inform the doctor.

In the case of larger complaints, an operation is necessary. After the surgical procedure, the child is weak and needs to rest for a few days. After leaving the hospital, it is the responsibility of the parents to watch the child, since there is a risk of complications. Information brochures and discussions with the doctor provide the necessary information to be able to optimally support the recovery at home.

If symptoms occur that indicate renewed narrowing between the renal pelvis and the ureter, the doctor must be informed. Diet should be particularly gentle in the first few days after the procedure. The sick child must also drink enough fluids. Finally, it is important to inform the child later about his illness, so that he can take advantage of the necessary medical check-ups independently.

Ureteral Stenosis