Definition and Overview

Pyeloplasty is a surgical procedure that involves repairing the renal pelvis as a treatment for ureteropelvic junction (UPJ) obstruction, which is common among children.

In the urinary system, the kidneys are responsible for filtering blood wastes and eliminating them by converting them into urine. Urine then flows from the kidney to the ureter then to the bladder, which has many nerves that are sensitive to the accumulation of urine. When it’s already filled, the sphincter muscles relax, allowing the urine to flow from the bladder to the urethra and then to the penis or vagina.

However, there are times when the tubes encounter problems such as an obstruction. In UPJ obstruction, something is blocking the uteropelvic junction, which is the area where the floor of the kidneys and the ureter meet. When this happens, urine can go back up to the kidneys, a condition called hydronephrosis, damaging the organs by compressing them.

Renal pelvis reconstruction is performed to remove the blockage, decompressing the kidneys in the process.

Who Should Undergo and Expected Results

Pyeloplasty is intended for people who have been diagnosed with UPJ obstruction. Although the condition can occur at any age, it is most commonly diagnosed among small children and even the ones still in utero. This is because hydronephrosis can be detected during a maternal ultrasound as early as the first semester. This means that as soon as the baby is born, the surgery can already be planned and executed.

There are many possible causes of the obstruction including the growth of polyps or tumours, wrong positioning of a blood vessel, the presence of a scar tissue, and kidney stones. For those in utero, the problem typically occurs due to foetal development abnormalities such as when the tubes progressively become narrow, causing strictures (constrictions).

Unless the condition has been detected during an ultrasound, the obstruction may not be easily determined as the child can be asymptomatic for some time. In the long term, he may begin to feel pain in the lower back where the kidneys are located, experience bleeding or pain when urinating, and develop recurrent urinary tract infections (UTI).

The success of renal pelvis reconstruction depends on the severity of the condition. The earlier it is diagnosed, the better are the chances of avoiding permanent damage to the kidneys. Although the procedure can cure the condition in many cases, it cannot prevent the development of UTI in the future.

How Does the Procedure Work?

Pyeloplasty can be a traditional open surgery, in which a single large incision is made on the side, or laparoscopic, where three small incisions are made in the same area. This is then followed up by the insertion of a laparoscope, a long narrow flexible tube that contains a camera that feeds images of the organs and the surrounding tissues in real time to a monitor.

Once the incisions are created, the urologic surgeon can proceed with the repair or reconstruction of the stricture by removing the blockage and connecting the ends of the ureter. There’s no need to use any artificial material to fix it. The stitches are then closed with dissolvable sutures.

The surgeon will also insert a catheter to the bladder from the urethra to drain any urine buildup or allow the patient to urinate during the procedure. A stent may also be placed to keep the ureter open, although this is normally removed a few weeks once the operated area has completely healed.

Renal pelvis reconstruction usually takes 3 to 4 hours and is performed under general anaesthesia, which means that the child is asleep and comfortable throughout the procedure.

Possible Risks and Complications

Inserting the catheter into the bladder may cause the urine to turn pink or brown. The patient may also feel the urge to urinate more frequently or feel discomfort and sometimes pain. Infection may also happen, so often, doctors prescribe antibiotics and pain mediations to the patient.


  • Elder JS. Obstruction of the urinary tract. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics.19th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 534.

  • Frokiaer J, Zeidel ML. Urinary tract obstruction. In: Taal MW, ed. Brenner and Rector's The Kidney. 9th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 35.

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