What Is Ureteropelvic Junction Obstruction?

One of the main jobs of the kidney is to filter the blood, and deliver the waste products (urine) to the bladder. The urine leaves the kidney, enters the renal pelvis, and then passes into the ureter through a funnel called the ureteropelvic junction (UPJ). In some children there can be a partial blockage at the UPJ. The blockage may be severe (high grade), minimal (low grade) or intermittent.

Contact Us Refer a Patient

How Is UPJ Obstruction Diagnosed?

Ultrasonography and intravenous urography (IVU) will show hydronephrosis (enlargement of the kidney) related to the UPJ obstruction. Other studies, such as a diuretic renal scan (DRS) may be needed to evaluate the function of the kidneys.

How Is UPJ Obstruction Treated?

The usual repair of a UPJ obstruction (pyeloplasty) involves removing the blockage, and reconnecting the ureter to the renal pelvis. Depending on the individual circumstances a tube may be left across the pyeloplasty (stent) or a tube may be left above the repair to decompress the kidney (nephrostomy).

What Is Pyeloplasty?

Pyeloplasty is a surgical procedure to relieve swelling of the kidney (hydronephrosis) that is caused by a blockage between the kidney and bladder (ureteropelvic junction obstruction). This blockage obstructs the flow of urine from the kidney to the bladder, causing the kidney to swell with excess urine. Pyeloplasty is the most common treatment for infants and children.

Post-Operative Care Instructions for Pyeloplasty

This surgery can be done in three different ways: open technique, laparoscopic, or laparoscopic with robotic assistance. Your surgeon will discuss each option with you and recommend the method that is best for your child and their individual situation.

What to Expect After Surgery

Most children spend 1 to 2 nights in the hospital following pyeloplasty.

It is normal to see some blood or small blood clots in the urine, when voiding, if your child has a stent in place. This can happen during the first few weeks after surgery. Stents can also cause some children to feel discomfort when urinating, especially on their backside, where the procedure was performed.

Please make sure your child does not engage in strenuous or high-intensity activities until the follow-up renal ultrasound.

Post-Surgery Follow Up

Your child may have one of the following that will remain in place after surgery and during the recovery period, and will be removed during a follow-up procedure.

Indwelling Ureteral Stent

This type of stent will be removed during an outpatient procedure in the operating room. Your child will go home the same day.

External Nephroureteral Stent/Tube

This type of stent/tube can be removed in the urologist's office during a follow-up appointment.

External JP Drain

We will need to monitor the output of the JP drain. During your post-operative recovery, we will call and ask how much draining your child is experiencing. Once the output is minimal, the drain will be removed in the urologist's office.

Usually, there are 2 follow-up appointments:

  • Your child will need to be seen 1 to 2 weeks after surgery. During this appointment, the external stent, tube or drain will be removed.
  • There will be an additional follow up 4 to 6 weeks after surgery (or after the stent/drain is removed). Your child will have a renal ultrasound to re-evaluate any swelling in the kidney or urinary tract. Your physician may recommend antibiotics until this repeat imaging is completed.

You should call the doctor if your child experiences any of the following:

  • You are having to empty the drain/stent constantly (high output), or it is not draining at all.
  • The dressing around the drain/stent is completely saturated and requires changing every few hours.
  • Pain is uncontrolled by pain medications.
  • Infection symptoms: fever greater than 101° F, spreading/increasing redness or swelling, foul-smelling urine draining from the drain/stent.
  • New or worsening symptoms of a urinary tract infection (frequency, burning with urination, urgency), increase in wetting accidents, fever, back/abdominal pain, nausea or vomiting.

Contact Us

UT Pediatric Urology
UT Physicians Professional Building
6410 Fannin St. Suite 950
Houston, Texas 77030
Phone: (832) 325-7234

To contact Children's Memorial Hermann Hospital, please fill out the form below.


Thank you for contacting Children’s Memorial Hermann Hospital. We have received your inquiry, and a team member will contact you soon.

If you need more immediate assistance, please call us at (713) 704-KIDS (5437).