Pyeloplasty: surgery for UPJ obstruction

Goal of the operation

In UPJ obstruction, urine cannot pass easily from the renal pelvis into the ureter. The goal of pyeloplasty is to remove the narrow segment so that urine flows freely, and to protect kidney function.

When is it needed?

Pyeloplasty is done when the obstruction is confirmed by symptoms or by repeated imaging. The main indications are:

• recurrent flank pain or febrile urinary tract infection,
• split renal function on MAG3/DTPA below 40%, or a drop of more than 10 percentage points during follow-up,
• poor drainage from the pelvis after the diuretic,
• dilation that increases on ultrasound or is high grade (SFU III–IV).

The decision is based not on a single number but on how the dilation and kidney function change over time.

How is the operation done?

The standard method is the Anderson-Hynes pyeloplasty: the narrow segment is cut out, part of the enlarged pelvis is reduced, and the ureter is stitched back to the pelvis with a wide, funnel-shaped connection. If a blood vessel is pressing on it, the ureter is moved in front of the vessel.

There are three surgical approaches:

• Open method: a 2–4 cm incision in the side. Often chosen for babies.
• Laparoscopic method: a camera and instruments through 3 small incisions.
• Robotic method: a robot-assisted form of laparoscopy, for older children.

Results are excellent with all methods.

Stent and drain

To help the stitched area heal, an internal JJ stent is usually placed in the ureter. It is usually removed after 4–6 weeks with a cystoscope under a short anesthetic. In some cases, the stent is an external tube that comes out through the skin and is removed without anesthesia.

In the hospital and at home

• The hospital stay is usually 1–3 days.
• In the first days, mild pain and a little blood in the urine are normal.
• At home, no heavy physical activity for 2 weeks.
• While the stent is in, plenty of fluids; if there is a fever, seek care right away.

Follow-up

• ultrasound 4–6 weeks after stent removal,
• then ultrasound at 3–6 and 12 months,
• MAG3/DTPA after 6–12 months if needed.

The dilation takes months to decrease and may not disappear completely. The main sign of success is that urine flows easily and kidney function is preserved. Repeat narrowing is rare.